Human population-specific gene expression and transcriptional network modification with polymorphic transposable elements

PubMed Central

Wang, Lu; Mariño-Ramírez, Leonardo

2017-01-01

Abstract Transposable element (TE) derived sequences are known to contribute to the regulation of the human genome. The majority of known TE-derived regulatory sequences correspond to relatively ancient insertions, which are fixed across human populations. The extent to which human genetic variation caused by recent TE activity leads to regulatory polymorphisms among populations has yet to be thoroughly explored. In this study, we searched for associations between polymorphic TE (polyTE) loci and human gene expression levels using an expression quantitative trait loci (eQTL) approach. We compared locus-specific polyTE insertion genotypes to B cell gene expression levels among 445 individuals from 5 human populations. Numerous human polyTE loci correspond to both cis and trans eQTL, and their regulatory effects are directly related to cell type-specific function in the immune system. PolyTE loci are associated with differences in expression between European and African population groups, and a single polyTE loci is indirectly associated with the expression of numerous genes via the regulation of the B cell-specific transcription factor PAX5. The polyTE-gene expression associations we found indicate that human TE genetic variation can have important phenotypic consequences. Our results reveal that TE-eQTL are involved in population-specific gene regulation as well as transcriptional network modification. PMID:27998931

Lack of association of the TP53 Arg72Pro SNP and the MDM2 SNP309 with systemic lupus erythematosus in Caucasian, African American, and Asian children and adults.

PubMed

Onel, K B; Huo, D; Hastings, D; Fryer-Biggs, J; Crow, M K; Onel, K

2009-01-01

The p53 tumour suppressor is the central regulator of apoptosis. Previously, the functional TP53 Arg72Pro polymorphism was found to be associated with systemic lupus erythematosus (SLE) in Koreans but not Spaniards. MDM2 is the major negative regulator of p53. An intronic polymorphism in MDM2, the SNP309, attenuates p53 activity and is associated with accelerated tumour development in premenopausal women. Polymorphic variation in MDM2 has never been studied in SLE. The aim of this study is to further assess the contribution of p53-pathway genetic variation to SLE by testing the association of the TP53 Arg72Pro polymorphism and the MDM2 SNP309 with SLE in a well-characterised and ethnically diverse cohort of patients with both childhood- and adult-onset SLE (n = 314). No association was found between the TP53 Arg72Pro polymorphism and SLE in patients of European descent, Asian descent or in African Americans, nor was an association found between the MDM2 SNP309 and SLE in patients of European descent or in African Americans. In addition, there was no correlation between either variant and early-onset disease or nephritis, an index of severe disease. It is concluded that neither the TP53 Arg72Pro polymorphism nor the MDM2 SNP309 contributes significantly to either susceptibility or disease severity in SLE.

G-protein-coupled receptor kinase 4 polymorphisms and blood pressure response to metoprolol among African Americans: sex-specificity and interactions.

PubMed

Bhatnagar, Vibha; O'Connor, Daniel T; Brophy, Victoria H; Schork, Nicholas J; Richard, Erin; Salem, Rany M; Nievergelt, Caroline M; Bakris, George L; Middleton, John P; Norris, Keith C; Wright, Jackson; Hiremath, Leena; Contreras, Gabriel; Appel, Lawrence J; Lipkowitz, Michael S

2009-03-01

African Americans have a disproportionate burden of hypertension and comorbid disease. Pharmacogenetic markers of blood pressure response have yet to be defined clearly. This study explores the association between G-protein-coupled receptor kinase type 4 (GRK4) variants and blood pressure response to metoprolol among African Americans with early hypertensive nephrosclerosis. Participants from the African American Study of Kidney Disease and Hypertension (AASK) trial were genotyped at three GRK4 polymorphisms: R65L, A142V, and A486V. A Cox proportional hazards model, stratified by gender, was used to determine the relationship between GRK4 variants and time to reach a mean arterial pressure (MAP) of 107 mm Hg, adjusted for other predictors of blood pressure response. Potential interactions between the three polymorphisms were explored by analyzing the effects of gene haplotypes and by stratifying the analysis by neighboring sites. The hazard ratio with 95% confidence interval by A142V among men randomized to a usual MAP (102-107 mm Hg) was 1.54 (1.11-2.44; P = 0.0009). The hazard ratio by A142V with R65/L65 or L65/L65 was 2.14 (1.35-3.39; P = 0.001). Haplotype analyses were consistent but inconclusive. There was no association between A142V and blood pressure response among women. Results suggest a sex-specific relationship between GRK4 A142V and blood pressure response among African-American men with early hypertensive nephrosclerosis. Men with a GRK4 A142 were less responsive to metoprolol if they had a GRK4 L65 variant. The effect of GRK4 variants and blood pressure response to metoprolol should be studied in larger clinical trials.

Polymorphisms in the non-muscle myosin heavy chain 9 gene (MYH9) are strongly associated with end-stage renal disease historically attributed to hypertension in African Americans

PubMed Central

Freedman, Barry I.; Hicks, Pamela J.; Bostrom, Meredith A.; Cunningham, Mary E.; Liu, Yongmei; Divers, Jasmin; Kopp, Jeffrey B.; Winkler, Cheryl A.; Nelson, George W.; Langefeld, Carl D.; Bowden, Donald W.

2009-01-01

African Americans have high incidence rates of end-stage renal disease (ESRD) labeled as due to hypertension. As recent studies showed strong association with idiopathic and HIV-related focal segmental glomerulosclerosis and non-muscle myosin heavy chain 9 (MYH9) gene polymorphisms in this ethnic group, we tested for MYH9 associations in a variety of kidney diseases. Fifteen MYH9 single-nucleotide polymorphisms were evaluated in 175 African Americans with chronic glomerulonephritis-associated ESRD, 696 African Americans reportedly with hypertension-associated ESRD, and 948 control subjects without kidney disease. Significant associations were detected with 14 of the 15 polymorphisms in all 871 non-diabetic patients with ESRD. In hypertension-associated ESRD cases alone, significant associations were found with 13 MYH9 polymorphisms and the previously reported E1 haplotype. Thus, hypertension-associated ESRD in African Americans is substantially related to MYH9 gene polymorphisms and this may explain the poor response to blood pressure control in those diagnosed with hypertensive nephrosclerosis. It is possible that many African Americans classified as having hypertension-associated ESRD have occult MYH9-associated segmental or global glomerulosclerosis. Our study shows that gene-environment and/or gene–gene interactions may initiate kidney disease in genetically susceptible individuals, because African Americans homozygous for MYH9 risk alleles do not universally develop kidney disease. PMID:19177153

Pharmacogenetics of human 3'-phosphoadenosine 5'-phosphosulfate synthetase 1 (PAPSS1): gene resequencing, sequence variation, and functional genomics.

PubMed

Xu, Zhen-Hua; Thomae, Bianca A; Eckloff, Bruce W; Wieben, Eric D; Weinshilboum, Richard M

2003-06-01

3'-Phosphoadenosine 5'-phosphosulfate (PAPS) is the high-energy "sulfate donor" for reactions catalyzed by sulfotransferase (SULT) enzymes. The strict requirement of SULTs for PAPS suggests that PAPS synthesis might influence the rate of sulfate conjugation. In humans, PAPS is synthesized from ATP and SO(4)(2-) by two isoforms of PAPS synthetase (PAPSS): PAPSS1 and PAPSS2. As a step toward pharmacogenetic studies, we have resequenced the entire coding sequence of the human PAPSS1 gene, including exon-intron splice junctions, using DNA samples from 60 Caucasian-American and 58 African-American subjects. Twenty-one genetic polymorphisms were observed-1 insertion-deletion event and 20 single nucleotide polymorphisms (SNPs)-including two non-synonymous coding SNPs (cSNPs) that altered the following amino acids: Arg333Cys and Glu531Gln. Twelve pairs of these polymorphisms were tightly linked, and a total of twelve unequivocal haplotypes could be identified-two that were common to both ethnic groups and ten that were ethnic-specific. The Arg333Cys polymorphism, with an allele frequency of 2.5%, was observed only in DNA samples from Caucasian subjects. The Glu531Gln polymorphism was rare, with only a single copy of that allele in a DNA sample from an African-American subject. Transient expression in mammalian cells showed that neither of the non-synonymous cSNPs resulted in a change in the basal level of enzyme activity measured under optimal assay conditions. However, the Glu531Gln polymorphism altered the substrate kinetic properties of the enzyme. The Gln531 variant allozyme had a 5-fold higher K(m) value for SO(4)(2-) than did the wild-type allozyme and displayed monophasic kinetics for Na(2)SO(4). The wild-type allozyme (Glu531) showed biphasic kinetics for that substrate. These observations represent a step toward testing the hypothesis that genetic variation in PAPS synthesis catalyzed by PAPSS1 might alter in vivo sulfate conjugation.

Lack of Association of the TP53 Arg72Pro SNP and the MDM2 SNP309 with systemic lupus erythematosus in Caucasian, African American, and Asian children and adults

PubMed Central

Onel, KB; Huo, D; Hastings, D; Fryer-Biggs, J; Crow, MK; Onel, K

2009-01-01

The p53 tumour suppressor is the central regulator of apoptosis. Previously, the functional TP53 Arg72Pro polymorphism was found to be associated with systemic lupus erythematosus (SLE) in Koreans but not Spaniards. MDM2 is the major negative regulator of p53. An intronic polymorphism in MDM2, the SNP309, attenuates p53 activity and is associated with accelerated tumour development in premenopausal women. Polymorphic variation in MDM2 has never been studied in SLE. The aim of this study is to further assess the contribution of p53-pathway genetic variation to SLE by testing the association of the TP53 Arg72Pro polymorphism and the MDM2 SNP309 with SLE in a well-characterised and ethnically diverse cohort of patients with both childhood- and adult-onset SLE (n = 314). No association was found between the TP53 Arg72Pro polymorphism and SLE in patients of European descent, Asian descent or in African Americans, nor was an association found between the MDM2 SNP309 and SLE in patients of European descent or in African Americans. In addition, there was no correlation between either variant and early-onset disease or nephritis, an index of severe disease. It is concluded that neither the TP53 Arg72Pro polymorphism nor the MDM2 SNP309 contributes significantly to either susceptibility or disease severity in SLE. PMID:19074170

Genetic Variation in TLR Genes in Ugandan and South African Populations and Comparison with HapMap Data

PubMed Central

Randhawa, April Kaur; Horne, David J.; Adams, Mark D.; Shey, Muki; Barnholtz-Sloan, Jill; Mayanja-Kizza, Harriet; Kaplan, Gilla; Hanekom, Willem A.; Boom, W. Henry; Hawn, Thomas R.; Stein, Catherine M.

2012-01-01

Genetic epidemiological studies of complex diseases often rely on data from the International HapMap Consortium for identification of single nucleotide polymorphisms (SNPs), particularly those that tag haplotypes. However, little is known about the relevance of the African populations used to collect HapMap data for study populations conducted elsewhere in Africa. Toll-like receptor (TLR) genes play a key role in susceptibility to various infectious diseases, including tuberculosis. We conducted full-exon sequencing in samples obtained from Uganda (n = 48) and South Africa (n = 48), in four genes in the TLR pathway: TLR2, TLR4, TLR6, and TIRAP. We identified one novel TIRAP SNP (with minor allele frequency [MAF] 3.2%) and a novel TLR6 SNP (MAF 8%) in the Ugandan population, and a TLR6 SNP that is unique to the South African population (MAF 14%). These SNPs were also not present in the 1000 Genomes data. Genotype and haplotype frequencies and linkage disequilibrium patterns in Uganda and South Africa were similar to African populations in the HapMap datasets. Multidimensional scaling analysis of polymorphisms in all four genes suggested broad overlap of all of the examined African populations. Based on these data, we propose that there is enough similarity among African populations represented in the HapMap database to justify initial SNP selection for genetic epidemiological studies in Uganda and South Africa. We also discovered three novel polymorphisms that appear to be population-specific and would only be detected by sequencing efforts. PMID:23112821

The combined risks of reduced or increased function variants in cell death pathway genes differentially influence cervical cancer risk and herpes simplex virus type 2 infection among black Africans and the Mixed Ancestry population of South Africa.

PubMed

Chattopadhyay, Koushik; Williamson, Anna-Lise; Hazra, Annapurna; Dandara, Collet

2015-10-12

Cervical cancer is one of the most important cancers worldwide with a high incident and mortality rate and is caused by the human papilloma virus (HPV). Among sexually active women who get infected with human papillomavirus (HPV), a small fraction progresses to cervical cancer disease pointing to possible roles of additional risk factors in development of the disease which include host genetic factors and other infections such as HSV-2. Since cellular apoptosis plays a role in controlling the spread of virus-infections in cells, gene variants altering the function of proteins involved in cell death pathways might be associated with the clearing of virus infections. Activity altering polymorphisms in FasR (-1377G > A and -670A > G), FasL (-844 T > C) and CASP8 (-652 6 N ins/del) genes have been shown to alter the mechanism of apoptosis by modifying the level of expression of their correspondent proteins. In the present study, we set out to investigate the combined risks of CASP8, FasR, and FasL polymorphisms in cervical cancer, pre-cancerous lesions, HPV infection and HSV-2 infection. Participants were 442 South African women of black African and mixed-ancestry origin with invasive cervical cancer and 278 control women matched by age, ethnicity and domicile status. FasR and FasL polymorphisms were genotyped by TaqMan and CASP8 polymorphism by PCR-RFLP. The results were analysed with R using haplo.stats software version 1.5.2. CASP8 -652 6 N del + FasR-670A was associated with a reduced risk (P = 0.019, Combined Polymorphism Score (CPS) = -2.34) and CASP8 -652 6 N ins + FasR-1377G was associated with a marginal increased risk (P = 0.047, CPS = 1.99) of cervical cancer among black Africans. When compared within the control group, CASP8 -652 6 N ins + FasR-1377A showed a reduced risk (P = 0.023, CPS = -2.28) of HSV-2 infection in both black African and mixed-ancestry population. Our results show that the combined risks of variants in cell death pathway genes are associated with the cervical cancer as well as the HSV-2 infection in the black African and mixed-ancestry population.

Common polymorphic variation in the genetically diverse African insulin gene and its association with size at birth.

PubMed

Petry, Clive J; Rayco-Solon, Pura; Fulford, Anthony J C; Stead, John D H; Wingate, Dianne L; Ong, Ken K; Sirugo, Giorgio; Prentice, Andrew M; Dunger, David B

2009-09-01

The insulin variable number of tandem repeats (INS VNTR) has been variably associated with size at birth in non-African populations. Small size at birth is a major determinant of neonatal mortality, so the INS VNTR may influence survival. We tested the hypothesis, therefore, that genetic variation around the INS VNTR in a rural Gambian population, who experience seasonal variation in nutrition and subsequently birth weight, may be associated with foetal and early growth. Six polymorphisms flanking the INS VNTR were genotyped in over 2,500 people. Significant associations were detected between the maternally inherited SNP 27 (rs689) allele and birth length [effect size 17.5 (5.2-29.8) mm; P = 0.004; n = 361]. Significant associations were also found between the maternally inherited African-specific SNP 28 (rs5506) allele and post-natal weight gain [effect size 0.19 (0.05-0.32) z score points/year; P = 0.005; n = 728). These results suggest that in the Gambian population studied there are associations between polymorphic variation in the genetically diverse INS gene and foetal and early growth characteristics, which contribute to overall polygenic associations with these traits.

G-Protein-Coupled Receptor Kinase 4 Polymorphisms and Blood Pressure Response to Metoprolol Among African Americans: Sex-Specificity and Interactions

PubMed Central

Bhatnagar, Vibha; O’Connor, Daniel T.; Brophy, Victoria H.; Schork, Nicholas J.; Richard, Erin; Salem, Rany M.; Nievergelt, Caroline M.; Bakris, George L.; Middleton, John P.; Norris, Keith C.; Wright, Jackson; Hiremath, Leena; Contreras, Gabriel; Appel, Lawrence J.; Lipkowitz, Michael S.

2009-01-01

BACKGROUND African Americans have a disproportionate burden of hypertension and comorbid disease. Pharmacogenetic markers of blood pressure response have yet to be defined clearly. This study explores the association between G-protein-coupled receptor kinase type 4 (GRK4) variants and blood pressure response to metoprolol among African Americans with early hypertensive nephrosclerosis. METHODS Participants from the African American Study of Kidney Disease and Hypertension (AASK) trial were genotyped at three GRK4 polymorphisms: R65L, A142V, and A486V. A Cox proportional hazards model, stratified by gender, was used to determine the relationship between GRK4 variants and time to reach a mean arterial pressure (MAP) of 107 mm Hg, adjusted for other predictors of blood pressure response. Potential interactions between the three polymorphisms were explored by analyzing the effects of gene haplotypes and by stratifying the analysis by neighboring sites. RESULTS The hazard ratio with 95% confidence interval by A142V among men randomized to a usual MAP (102–107 mm Hg) was 1.54 (1.11–2.44; P = 0.0009). The hazard ratio by A142V with R65/L65 or L65/L65 was 2.14 (1.35–3.39; P = 0.001). Haplotype analyses were consistent but inconclusive. There was no association between A142V and blood pressure response among women. CONCLUSIONS Results suggest a sex-specific relationship between GRK4 A142V and blood pressure response among African-American men with early hypertensive nephrosclerosis. Men with a GRK4 A142 were less responsive to metoprolol if they had a GRK4 L65 variant. The effect of GRK4 variants and blood pressure response to metoprolol should be studied in larger clinical trials. PMID:19119263

Evaluation of Human FcγRIIA (CD32) and FcγRIIIB (CD16) Polymorphisms in Caucasians and African-Americans Using Salivary DNA

PubMed Central

van Schie, Rob C. A. A.; Wilson, Mark E.

2000-01-01

Two classes of low-affinity receptors for the Fc region of immunoglobulin G (IgG) (FcγR) are constitutively expressed on resting human neutrophils. These receptors, termed FcγRIIa (CD32) and FcγRIIIb (CD16), display biallelic polymorphisms which have functional consequences with respect to binding and/or ingestion of targets opsonized by human IgG subclass antibodies. The H131-R131 polymorphism of CD32 influences binding of human IgG2 and, to a lesser extent, human IgG3 to neutrophils. The neutrophil antigen (NA1-NA2) polymorphism of CD16 influences the efficiency of phagocytosis of bacteria opsonized by human IgG1 and IgG3. These polymorphisms may influence host susceptibility to certain infectious and/or autoimmune diseases, prompting interest in the development of facile methods for determination of CD32 and CD16 genotype in various clinical settings. We previously reported that genomic DNA from saliva is a suitable alternative to DNA from blood in PCR-based analyses of CD32 and CD16 polymorphisms. In the present study, we utilized for the first time this salivary DNA-based methodology to define CD32 and CD16 genotypes in 271 Caucasian and 118 African-American subjects and to investigate possible linkage disequilibrium between certain CD32 and CD16 genotypes in these two ethnic groups. H131 and R131 gene frequencies were 0.45 and 0.55, respectively, among Caucasians and 0.59 among African-Americans. NA1 and NA2 gene frequencies were 0.38 and 0.62 among Caucasians and 0.39 and 0.61 among African-Americans. Since FcγRIIa and FcγRIIIb synergize in triggering neutrophils, we also assessed the frequency of different CD32 and CD16 genotype combinations in these two groups. In both groups, the R/R131-NA2/NA2 genotype combination was more common than the H/H131-NA1/NA1 combination (threefold for Caucasians versus sevenfold for African-Americans). Whether individuals with the combined R/R131-NA2/NA2 genotype are at greater risk for development of infectious and/or autoimmune diseases requires further investigation, which can be conveniently performed using DNA from saliva rather than blood. PMID:10882671

Association of cocaine- and amphetamine-related transcript, leptin and leptin receptor gene polymorphisms with anthropometric obesity phenotype indicators in South African learners.

PubMed

Yako, Y Y; Fanampe, B L; Hassan, M S; Erasmus, R T; van der Merwe, L; van Rensburg, S J; Matsha, T E

2011-01-01

Obesity has increased rapidly in South African children and adolescents. Genes involved in appetite regulation have been extensively studied worldwide, but their role in the obesity phenotype in South African Black and mixed-ancestry school adolescents is unknown. Seven common polymorphisms in LEP, GHRL, CART and LEPR were analysed for genotype and haplotype association with anthropometric obesity phenotype indicators in South African Black and mixed-ancestry adolescent school learners. The CART c.517A→G polymorphism was significantly associated with obesity susceptibility. The LEPR Lys(109)Arg G allele was associated with an average reduction of 2.36 kg/m(2) in body mass index (BMI), 5.66 cm in waist circumference (WC) and 1.61 cm in mid-upper-arm circumference (MUAC). This was confirmed by haplotype analysis. Additionally, a haplotype of the LEP polymorphisms significantly increased BMI, MUAC and hip circumference, while LEPR haplotypes were associated with differences in MUAC. Our findings suggest that c.517A→G and Lys(109)Arg contribute to the variation in anthropometric obesity phenotype indicators observed among Black African and mixed-ancestry South African learners. Furthermore, haplotypes of LEP, LEPR and GHRL polymorphisms were associated with varying measurements of weight, BMI and WC. Further studies are required to confirm our results in a larger and homogeneous study population group. Copyright © 2011 S. Karger AG, Basel.

Fcγ receptor IIIa single-nucleotide polymorphisms and haplotypes affect human IgG binding and are associated with lupus nephritis in African Americans.

PubMed

Dong, Chaoling; Ptacek, Travis S; Redden, David T; Zhang, Kui; Brown, Elizabeth E; Edberg, Jeffrey C; McGwin, Gerald; Alarcón, Graciela S; Ramsey-Goldman, Rosalind; Reveille, John D; Vilá, Luis M; Petri, Michelle; Qin, Aijian; Wu, Jianming; Kimberly, Robert P

2014-05-01

To investigate whether the Fcγ receptor IIIa-66L/R/H (FcγRIIIa-66L/R/H) polymorphism influences net effective receptor function and to assess if the FCGR3A combined genotypes formed by FcγRIIIa-66L/R/H and FcγRIIIa-176F/V, as well as copy number variation (CNV), confer risk of developing systemic lupus erythematosus (SLE) and lupus nephritis. FcγRIIIa variants, expressed on A20 IIA1.6 cells, were used in flow cytometry-based human IgG-binding assays. Using Pyrosequencing methodology, FCGR3A single-nucleotide polymorphism and CNV genotypes were determined in a cohort of 1,728 SLE patients and 2,404 healthy controls. The FcγRIIIa-66L/R/H (rs10127939) polymorphism influenced ligand binding capacity in the presence of the FcγRIIIa-176V (rs396991) allele. There was a trend toward an association of the low-binding FcγRIIIa-176F allele with lupus nephritis among African Americans (P = 0.0609) but not among European Americans (P > 0.10). Nephritis among African American patients with SLE was associated with FcγRIIIa low-binding haplotypes containing the 66L/R/H and 176F variants (P = 0.03) and with low-binding genotype combinations (P = 0.002). No association was observed among European American patients with SLE. The distribution of FCGR3A CNV was not significantly different among controls and SLE patients with or without nephritis. FcγRIIIa-66L/R/H influences ligand binding. The low-binding haplotypes formed by 66L/R/H and 176F confer enhanced risk of lupus nephritis in African Americans. FCGR3A CNVs are not associated with SLE or lupus nephritis in either African Americans or European Americans. Copyright © 2014 by the American College of Rheumatology.

Manganese superoxide dismutase Ala-9Val polymorphism and risk of breast cancer in a population-based case–control study of African Americans and whites

PubMed Central

Millikan, Robert C; Player, Jon; de Cotret, Allan René; Moorman, Patricia; Pittman, Gary; Vannappagari, Vani; Tse, Chiu-Kit J; Keku, Temitope

2004-01-01

Introduction A polymorphism in the manganese superoxide dismutase (MnSOD) gene, Ala-9Val, has been examined in association with breast cancer risk in several epidemiologic studies. Results suggest that the Ala allele increases the risk of breast cancer and modifies the effects of environmental exposures that produce oxidative damage to DNA. Methods We examined the role of the MnSOD Ala-9Val polymorphism in a population-based case–control study of invasive and in situ breast cancer in North Carolina. Genotypes were evaluated for 2025 cases (760 African Americans and 1265 whites) and for 1812 controls (677 African Americans and 1135 whites). Results The odds ratio for MnSOD Ala/Ala versus any MnSOD Val genotypes was not elevated in African Americans (odds ratio = 0.9, 95% confidence interval = 0.7–1.2) or in whites (odds ratio = 1.0, 95% confidence interval = 0.8–1.2). Greater than additive joint effects were observed for the Ala/Ala genotype and smoking, radiation to the chest, and occupational exposure to ionizing radiation. Antagonism was observed between the Ala/Ala genotype and the use of nonsteroidal anti-inflammatory drugs. Conclusions The MnSOD genotype may contribute to an increased risk of breast cancer in the presence of specific environmental exposures. These results provide further evidence for the importance of reactive oxygen species and of oxidative DNA damage in the etiology of breast cancer. PMID:15217492

Effects of dopamine D2 receptor (DRD2) and transporter (SLC6A3) polymorphisms on smoking cue-induced cigarette craving among African-American smokers.

PubMed

Erblich, J; Lerman, C; Self, D W; Diaz, G A; Bovbjerg, D H

2005-04-01

Cue-induced craving for addictive substances has long been known to contribute to the problem of persistent addiction in humans. Research in animals over the past decade has solidly established the central role of dopamine in cue-induced craving for addictive substances, including nicotine. Analogous studies in humans, however, are lacking, especially among African-American smokers, who have lower quit rates than Caucasian smokers. Based on the animal literature, the study's objective was to test the hypothesis that smokers carrying specific variants in dopamine-related genes previously associated with risk for addictive behaviors would exhibit heightened levels of cigarette craving following laboratory exposure to cues. To this end, cigarette craving was induced in healthy African-American smokers (n=88) through laboratory exposure to smoking cues. Smokers carrying either the DRD2 (D2 dopamine receptor gene) TaqI A1 RFLP or the SLC6A3 (dopamine transporter gene) 9-repeat VNTR polymorphisms had stronger cue-induced cravings than noncarriers (Ps <0.05 and 0.01, respectively). Consistent with the separate biological pathways involved (receptor, transporter), carriers of both polymorphisms had markedly higher craving responses compared to those with neither (P<0.0006), reflecting additive effects. Findings provide support for the role of dopamine in cue-induced craving in humans, and suggest a possible genetic risk factor for persistent smoking behavior in African-American smokers.

Detection of DNA "fingerprints" of cultivated rice by hybridization with a human minisatellite DNA probe.

PubMed

Dallas, J F

1988-09-01

A human minisatellite DNA probe detects several restriction fragment length polymorphisms in cultivars of Asian and African rice. Certain fragments appear to be inherited in a Mendelian fashion and may represent unlinked loci. The hybridization patterns appear to be cultivar-specific and largely unchanged after the regeneration of plants from tissue culture. The results suggest that these regions of the rice genome may be used to generate cultivar-specific DNA fingerprints. The demonstration of similarity between a human minisatellite sequence and polymorphic regions in the rice genome suggests that such regions also occur in the genomes of many other plant species.

Associations between polymorphisms in the antiviral TRIM genes and measles vaccine immunity.

PubMed

Ovsyannikova, Inna G; Haralambieva, Iana H; Vierkant, Robert A; O'Byrne, Megan M; Poland, Gregory A

2013-06-01

The role of polymorphisms within the antiviral tripartite motif (TRIM) genes in measles vaccine adaptive immune responses was examined. A limited association was found between TRIM5 (rs7122620) and TRIM25 (rs205499) gene polymorphisms and measles-specific antibody levels. However, many associations were found between TRIM gene SNPs and variations in cellular responses (IFN-γ Elispot and secreted cytokines IL-2, IL-6, IL-10, IFN-γ, and TNF-α). TRIM22 rs2291841 was significantly associated with an increased IFN-γ Elispot response (35 vs. 102 SFC per 2×10(5)PBMC, p=0.009, q=0.71) in Caucasians. A non-synonymous TRIM25 rs205498 (in LD with other SNPs, r(2)≥0.56), as well as the TRIM25 AAAGGAAAGGAGT haplotype, was associated with a decreased IFN-γ Elispot response (t-statistic -2.32, p=0.02) in African-Americans. We also identified polymorphisms in the TRIM5, TRIM22, and TRIM25 genes that were associated with significant differences in cytokine responses. Additional studies are necessary to replicate our findings and to examine the functional consequences of these associations. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

TSLP Polymorphisms are Associated with Asthma in a Sex-Specific Fashion

PubMed Central

Hunninghake, Gary M.; Soto-Quirós, Manuel E.; Avila, Lydiana; Kim, Hong P.; Lasky-Su, Jessica; Rafaels, Nicholas; Ruczinski, Ingo; Beaty, Terry H.; Mathias, Rasika A.; Barnes, Kathleen C.; Wilk, Jemma B.; O’Connor, George T.; Gauderman, W. James; Vora, Hita; Baurley, James W.; Gilliland, Frank; Liang, Catherine; Sylvia, Jody S.; Klanderman, Barbara J.; Sharma, Sunita S.; Himes, Blanca E.; Bossley, Cara J.; Israel, Elliot; Raby, Benjamin A.; Bush, Andrew; Choi, Augustine M.; Weiss, Scott T.; Celedón, Juan C.

2010-01-01

Background Single nucleotide polymorphisms (SNPs) in thymic stromal lymphopoietin (TSLP) have been associated with IgE (in girls) and asthma (in general). We sought to determine whether TSLP SNPs are associated with asthma in a sex-specific fashion. Methods We conducted regular and sex-stratified analyses of association between SNPs in TSLP and asthma in families of asthmatic children in Costa Rica. Significant findings were replicated in white and African-American participants in the Childhood Asthma Management Program, in African Americans in the Genomic Research on Asthma in the African Diaspora study, in whites and Hispanics in the Children’s Health Study, and in whites in the Framingham Heart Study (FHS). Main Results Two SNPs in TSLP (rs1837253 and rs2289276) were significantly associated with a reduced risk of asthma in combined analyses of all cohorts (p values of 2×10−5 and 1×10−5, respectively). In a sex-stratified analysis, the T allele of rs1837253 was significantly associated with a reduced risk of asthma in males only (p= 3×10−6). Alternately, the T allele of rs2289276 was significantly associated with a reduced risk of asthma in females only (p= 2×10−4). Findings for rs2289276 were consistent in all cohorts except the FHS. Conclusions TSLP variants are associated with asthma in a sex-specific fashion. PMID:20560908

TSLP polymorphisms are associated with asthma in a sex-specific fashion.

PubMed

Hunninghake, G M; Soto-Quirós, M E; Avila, L; Kim, H P; Lasky-Su, J; Rafaels, N; Ruczinski, I; Beaty, T H; Mathias, R A; Barnes, K C; Wilk, J B; O'Connor, G T; Gauderman, W James; Vora, H; Baurley, J W; Gilliland, F; Liang, C; Sylvia, J S; Klanderman, B J; Sharma, S S; Himes, B E; Bossley, C J; Israel, E; Raby, B A; Bush, A; Choi, A M; Weiss, S T; Celedón, J C

2010-12-01

Single nucleotide polymorphisms (SNPs) in thymic stromal lymphopoietin (TSLP) have been associated with IgE (in girls) and asthma (in general). We sought to determine whether TSLP SNPs are associated with asthma in a sex-specific fashion. We conducted regular and sex-stratified analyses of association between SNPs in TSLP and asthma in families of children with asthma in Costa Rica. Significant findings were replicated in whites and African-American participants in the Childhood Asthma Management Program, in African-Americans in the Genomic Research on Asthma in the African Diaspora study, in whites and Hispanics in the Children's Health Study, and in whites in the Framingham Heart Study (FHS). Two SNPs in TSLP (rs1837253 and rs2289276) were significantly associated with a reduced risk of asthma in combined analyses of all cohorts (P values of 2 × 10(-5) and 1 × 10(-5) , respectively). In a sex-stratified analysis, the T allele of rs1837253 was significantly associated with a reduced risk of asthma in males only (P = 3 × 10(-6) ). Alternately, the T allele of rs2289276 was significantly associated with a reduced risk of asthma in females only (P = 2 × 10(-4) ). Findings for rs2289276 were consistent in all cohorts except the FHS. TSLP variants are associated with asthma in a sex-specific fashion. © 2010 John Wiley & Sons A/S.

[Distribution of three polymorphisms of the TSLP gen in African-descendent population from San Basilio de Palenque, Colombia].

PubMed

Fang, Luis; Martínez, Beatriz; Marrugo, Javier

2013-01-01

Thymic stromal lymphopoietin (TSLP) has been linked as a susceptibility gene for the development of allergic diseases. It is known that the population of Cartagena is a triethnic mix, in which the component of African ancestry was significantly associated with risk of asthma and high total serum IgE levels. This component comes from African slaves brought into the continent and settled in "palenques", one of them is San Basilio de Palenque, in the Colombian Caribbean Coast. To analyze the distribution of single nucleotide polymorphisms (SNP) rs1837253, rs17551370 and rs2289276 located in TSLP gene, in the African-descendent population of San Basilio de Palenque. By real time-PCR and probes TaqMan SNP Genotyping™, we genotyped three polymorphisms in 80 individuals of African-descent aged 5 to 18 years of age. The frequency of the rs1837253 allele T was 41.9%, for the allele A, 14.3% for rs17551370, and 22.5% for the allele T of rs2289276. The rs17551370 and rs2289276 distribution remained in Hardy- Weinberg genetic equilibrium. The allele frequency of each SNP did not show statistically significant differences with those reported for other African and African-descendent populations. The three polymorphisms in the TSLP were present in the sample population of San Basilio de Palenque and its distribution is similar to that reported for African populations and African ancestry in America.

Interleukin-6 (IL-6) rs1800796 and cyclin dependent kinase inhibitor (CDKN2A/CDKN2B) rs2383207 are associated with ischemic stroke in indigenous West African Men.

PubMed

Akinyemi, Rufus; Arnett, Donna K; Tiwari, Hemant K; Ovbiagele, Bruce; Sarfo, Fred; Srinivasasainagendra, Vinodh; Irvin, Marguerite Ryan; Adeoye, Abiodun; Perry, Rodney T; Akpalu, Albert; Jenkins, Carolyn; Owolabi, Lukman; Obiako, Reginald; Wahab, Kolawole; Sanya, Emmanuel; Komolafe, Morenikeji; Fawale, Michael; Adebayo, Philip; Osaigbovo, Godwin; Sunmonu, Taofiki; Olowoyo, Paul; Chukwuonye, Innocent; Obiabo, Yahaya; Akpa, Onoja; Melikam, Sylvia; Saulson, Raelle; Kalaria, Raj; Ogunniyi, Adesola; Owolabi, Mayowa

2017-08-15

Inherited genetic variations offer a possible explanation for the observed peculiarities of stroke in sub - Saharan African populations. Interleukin-6 polymorphisms have been previously associated with ischemic stroke in some non-African populations. Herein we investigated, for the first time, the association of genetic polymorphisms of IL-6, CDKN2A- CDKN2B and other genes with ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study. Twenty-three previously identified single nucleotide polymorphisms (SNPs) in 14 genes of relevance to the neurobiology of ischemic stroke were investigated. Logistic regression models adjusting for known cardiovascular disease risk factors were constructed to assess the associations of the 23 SNPs in rigorously phenotyped cases (N=429) of ischemic stroke (Men=198; Women=231) and stroke- free (N=483) controls (Men=236; Women=247). Interleukin-6 (IL6) rs1800796 (C minor allele; frequency: West Africans=8.6%) was significantly associated with ischemic stroke in men (OR=2.006, 95% CI=[1.065, 3.777], p=0.031) with hypertension in the model but not in women. In addition, rs2383207 in CDKN2A/CDKN2B (minor allele A with frequency: West Africans=1.7%) was also associated with ischemic stroke in men (OR=2.550, 95% CI=[1.027, 6.331], p=0.044) with primary covariates in the model, but not in women. Polymorphisms in other genes did not show significant association with ischemic stroke. Polymorphisms rs1800796 in IL6 gene and rs2383207 in CDKN2A/CDKN2B gene have significant associations with ischemic stroke in indigenous West African men. CDKN2A/CDKN2B SNP rs2383207 is independently associated with ischemic stroke in indigenous West African men. Further research should focus on the contributions of inflammatory genes and other genetic polymorphisms, as well as the influence of sex on the neurobiology of stroke in people of African ancestry. Copyright © 2017 Elsevier B.V. All rights reserved.

Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry.

PubMed

Gichohi-Wainaina, Wanjiku N; Tanaka, Toshiko; Towers, G Wayne; Verhoef, Hans; Veenemans, Jacobien; Talsma, Elise F; Harryvan, Jan; Boekschoten, Mark V; Feskens, Edith J; Melse-Boonstra, Alida

2016-01-01

Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations.

Associations between Common Variants in Iron-Related Genes with Haematological Traits in Populations of African Ancestry

PubMed Central

Tanaka, Toshiko; Towers, G. Wayne; Verhoef, Hans; Veenemans, Jacobien; Talsma, Elise F.; Harryvan, Jan; Boekschoten, Mark V.; Feskens, Edith J.; Melse-Boonstra, Alida

2016-01-01

Background Large genome-wide association (GWA) studies of European ancestry individuals have identified multiple genetic variants influencing iron status. Studies on the generalizability of these associations to African ancestry populations have been limited. These studies are important given interethnic differences in iron status and the disproportionate burden of iron deficiency among African ancestry populations. Methods We tested the associations of 20 previously identified iron status-associated single nucleotide polymorphisms (SNPs) in 628 Kenyans, 609 Tanzanians, 608 South Africans and 228 African Americans. In each study, we examined the associations present between 20 SNPs with ferritin and haemoglobin, adjusting for age, sex and CRP levels. Results In the meta analysis including all 4 African ancestry cohorts, we replicated previously reported associations with lowered haemoglobin concentrations for rs2413450 (β = -0.19, P = 0.02) and rs4820268 (β = -0.16, P = 0.04) in TMPRSS6. An association with increased ferritin concentrations was also confirmed for rs1867504 in TF (β = 1.04, P = <0.0001) in the meta analysis including the African cohorts only. Conclusions In all meta analyses, we only replicated 4 of the 20 single nucleotide polymorphisms reported to be associated with iron status in large GWA studies of European ancestry individuals. While there is now evidence for the associations of a number of genetic variants with iron status in both European and African ancestry populations, the considerable lack of concordance highlights the importance of continued ancestry-specific studies to elucidate the genetic underpinnings of iron status in ethnically diverse populations. PMID:27332551

An ImmunoChip study of multiple sclerosis risk in African Americans

PubMed Central

Isobe, Noriko; Madireddy, Lohith; Khankhanian, Pouya; Matsushita, Takuya; Caillier, Stacy J.; Moré, Jayaji M.; Gourraud, Pierre-Antoine; McCauley, Jacob L.; Beecham, Ashley H.; Piccio, Laura; Herbert, Joseph; Khan, Omar; Cohen, Jeffrey; Stone, Lael; Santaniello, Adam; Cree, Bruce A. C.; Onengut-Gumuscu, Suna; Rich, Stephen S.; Hauser, Stephen L.; Sawcer, Stephen

2015-01-01

The aims of this study were: (i) to determine to what degree multiple sclerosis-associated loci discovered in European populations also influence susceptibility in African Americans; (ii) to assess the extent to which the unique linkage disequilibrium patterns in African Americans can contribute to localizing the functionally relevant regions or genes; and (iii) to search for novel African American multiple sclerosis-associated loci. Using the ImmunoChip custom array we genotyped 803 African American cases with multiple sclerosis and 1516 African American control subjects at 130 135 autosomal single nucleotide polymorphisms. We conducted association analysis with rigorous adjustments for population stratification and admixture. Of the 110 non-major histocompatibility complex multiple sclerosis-associated variants identified in Europeans, 96 passed stringent quality control in our African American data set and of these, >70% (69) showed over-representation of the same allele amongst cases, including 21 with nominally significant evidence for association (one-tailed test P < 0.05). At a further eight loci we found nominally significant association with an alternate correlated risk-tagging single nucleotide polymorphism from the same region. Outside the regions known to be associated in Europeans, we found seven potentially associated novel candidate multiple sclerosis variants (P < 10−4), one of which (rs2702180) also showed nominally significant evidence for association (one-tailed test P = 0.034) in an independent second cohort of 620 African American cases and 1565 control subjects. However, none of these novel associations reached genome-wide significance (combined P = 6.3 × 10−5). Our data demonstrate substantial overlap between African American and European multiple sclerosis variants, indicating common genetic contributions to multiple sclerosis risk. PMID:25818868

An ImmunoChip study of multiple sclerosis risk in African Americans.

PubMed

Isobe, Noriko; Madireddy, Lohith; Khankhanian, Pouya; Matsushita, Takuya; Caillier, Stacy J; Moré, Jayaji M; Gourraud, Pierre-Antoine; McCauley, Jacob L; Beecham, Ashley H; Piccio, Laura; Herbert, Joseph; Khan, Omar; Cohen, Jeffrey; Stone, Lael; Santaniello, Adam; Cree, Bruce A C; Onengut-Gumuscu, Suna; Rich, Stephen S; Hauser, Stephen L; Sawcer, Stephen; Oksenberg, Jorge R

2015-06-01

The aims of this study were: (i) to determine to what degree multiple sclerosis-associated loci discovered in European populations also influence susceptibility in African Americans; (ii) to assess the extent to which the unique linkage disequilibrium patterns in African Americans can contribute to localizing the functionally relevant regions or genes; and (iii) to search for novel African American multiple sclerosis-associated loci. Using the ImmunoChip custom array we genotyped 803 African American cases with multiple sclerosis and 1516 African American control subjects at 130 135 autosomal single nucleotide polymorphisms. We conducted association analysis with rigorous adjustments for population stratification and admixture. Of the 110 non-major histocompatibility complex multiple sclerosis-associated variants identified in Europeans, 96 passed stringent quality control in our African American data set and of these, >70% (69) showed over-representation of the same allele amongst cases, including 21 with nominally significant evidence for association (one-tailed test P < 0.05). At a further eight loci we found nominally significant association with an alternate correlated risk-tagging single nucleotide polymorphism from the same region. Outside the regions known to be associated in Europeans, we found seven potentially associated novel candidate multiple sclerosis variants (P < 10(-4)), one of which (rs2702180) also showed nominally significant evidence for association (one-tailed test P = 0.034) in an independent second cohort of 620 African American cases and 1565 control subjects. However, none of these novel associations reached genome-wide significance (combined P = 6.3 × 10(-5)). Our data demonstrate substantial overlap between African American and European multiple sclerosis variants, indicating common genetic contributions to multiple sclerosis risk. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Associations of MC3R polymorphisms with physical activity in South African adolescents.

PubMed

Yako, Yandiswa Y; Hassan, Mogamat S; Erasmus, Rajiv T; van der Merwe, Lize; Janse van Rensburg, Susan; Matsha, Tandi Edith

2013-08-01

There is evidence demonstrating that the contribution of sedentary behavior and effect of physical activity on metabolic phenotypes is mediated by polymorphisms in genes. The type and frequency of physical activity was assessed by means of structured questionnaires in 1555 South African school learners. Anthropometric measurements, blood pressure, fasting blood glucose and lipids were measured using standard procedures. The effect of different types and frequency of physical activity on obesity-related traits was assessed in relation to MC3R T6K and V81I genotypes in 430 of the learners. Levels of total cholesterol were significantly lower in learners carrying the MC3R T6K and V81I minor alleles, after adjusting for age, race, gender, and each specific physical activity category. An activity-by-genotype interaction was also detected: learners heterozygous for the V81I polymorphism and performed house chores often had reduced total cholesterol. Though no association was observed between frequency of physical activity and BMI, television viewing was significantly associated with an increase in height, weight and marginally with waist circumference. Our findings suggest that physical activity even in the form of house chores has a positive effect on metabolic traits and this effect is further enhanced in the presence of MC3R polymorphisms.

Molecular Variation of Adh and P6 Genes in an African Population of Drosophila Melanogaster and Its Relation to Chromosomal Inversions

PubMed Central

Benassi, V.; Aulard, S.; Mazeau, S.; Veuille, M.

1993-01-01

Four-cutter molecular polymorphism of Adh and P6, and chromosome inversion polymorphism of chromosome II were investigated in 95 isogenic lines of an Ivory Coast population of Drosophila melanogaster, a species assumed to have recently spread throughout the world from a West African origin. The P6 gene showed little linkage disequilibrium with the In(2L)t inversion, although it is located within this inversion. This suggests that the inversion and the P6 locus have extensively exchanged genetic information through either double crossover or gene conversion. Allozymic variation in ADH was in linkage disequilibrium with In(2L)t and In(2R)NS inversions. Evidence suggests either that inversion linkage with the Fast allele is selectively maintained, or that this allele only recently appeared. Molecular polymorphism at the Adh locus in the Ivory Coast is not higher than in North American populations. New haplotypes specific to the African population were found, some of them connect the ``Wa(s)-like'' haplotypes found at high frequencies in the United States to the other slow haplotypes. Their relation with In(2L)t supports the hypothesis that Wa(s) recently recombined away from an In(2L)t chromosome which may be the cause of its divergence from the other haplotypes. PMID:8349110

Limited Evidence for Classic Selective Sweeps in African Populations

PubMed Central

Granka, Julie M.; Henn, Brenna M.; Gignoux, Christopher R.; Kidd, Jeffrey M.; Bustamante, Carlos D.; Feldman, Marcus W.

2012-01-01

While hundreds of loci have been identified as reflecting strong-positive selection in human populations, connections between candidate loci and specific selective pressures often remain obscure. This study investigates broader patterns of selection in African populations, which are underrepresented despite their potential to offer key insights into human adaptation. We scan for hard selective sweeps using several haplotype and allele-frequency statistics with a data set of nearly 500,000 genome-wide single-nucleotide polymorphisms in 12 highly diverged African populations that span a range of environments and subsistence strategies. We find that positive selection does not appear to be a strong determinant of allele-frequency differentiation among these African populations. Haplotype statistics do identify putatively selected regions that are shared across African populations. However, as assessed by extensive simulations, patterns of haplotype sharing between African populations follow neutral expectations and suggest that tails of the empirical distributions contain false-positive signals. After highlighting several genomic regions where positive selection can be inferred with higher confidence, we use a novel method to identify biological functions enriched among populations’ empirical tail genomic windows, such as immune response in agricultural groups. In general, however, it seems that current methods for selection scans are poorly suited to populations that, like the African populations in this study, are affected by ascertainment bias and have low levels of linkage disequilibrium, possibly old selective sweeps, and potentially reduced phasing accuracy. Additionally, population history can confound the interpretation of selection statistics, suggesting that greater care is needed in attributing broad genetic patterns to human adaptation. PMID:22960214

Steroid profiles of professional soccer players: an international comparative study.

PubMed

Strahm, E; Sottas, P-E; Schweizer, C; Saugy, M; Dvorak, J; Saudan, C

2009-12-01

Urinary steroid profiling is used in doping controls to detect testosterone abuse. A testosterone over epitestosterone (T/E) ratio exceeding 4.0 is considered as suspicious of testosterone administration, irrespectively of individual heterogeneous factors such as the athlete's ethnicity. A deletion polymorphism in the UGT2B17 gene was demonstrated to account for a significant part of the interindividual variability in the T/E between Caucasians and Asians. Here, the variability of urinary steroid profiles was examined in a widely heterogeneous cohort of professional soccer players. The steroid profile of 57 Africans, 32 Asians, 50 Caucasians and 32 Hispanics was determined by gas chromatography-mass spectrometry. Significant differences have been observed between all ethnic groups. After estimation of the prevalence of the UGT2B17 deletion/deletion genotype (African: 22%; Asian: 81%; Caucasian: 10%; Hispanic: 7%), ethnic-specific thresholds were developed for a specificity of 99% for the T/E (African: 5.6; Asian: 3.8; Caucasian: 5.7; Hispanic: 5.8). Finally, another polymorphism could be hypothesised in Asians based on specific concentration ratio of 5alpha-/5beta-androstane-3alpha,17beta-diol in urine. These results demonstrate that a unique and non-specific threshold to evidence testosterone misuse is not fit for purpose. An athlete's endocrinological passport consisting of a longitudinal follow-up together with the ethnicity and/or the genotype would strongly enhance the detection of testosterone abuse. Finally, additional genotyping studies should be undertaken to determine whether the remaining unexplained disparities have an environmental or a genetic origin.

A tale of aborigines, conquerors and slaves: Alu insertion polymorphisms and the peopling of Canary Islands.

PubMed

Maca-Meyer, N; Villar, J; Pérez-Méndez, L; Cabrera de León, A; Flores, C

2004-11-01

Classical, mitochondrial DNA (mtDNA) and Y chromosome markers have been used to examine the genetic admixture in present day inhabitants of the Canary Islands. In this study, we report the analysis of ten autosomal Alu insertion polymorphisms in 364 samples from the seven main islands of the Archipelago, and their comparison to continental samples. The detection of population-specific alleles from the Iberian Peninsula and Northwest Africa, as well as their affinities on the basis of genetic distances and principal component analysis, support a clear link between these populations. Coincident with previous results, the Canarian gene pool can be distinguished as being halfway between those of its putative parents, although with a major Iberian contribution (62-78%). Both the substantial Northwest African contribution (23-38%), and the minor sub-Saharan African input (3%), suggest that the genetic legacy from the aborigines and slaves still persists in the Canary Islanders.

Neuroantibodies (NAB) in African-American Children with Heavy Metal Exposures are Associated with Cytokine and Human Leukocyte Antigen (HLA) Polymorphisms (SNP)

EPA Science Inventory

Polymorphisms in cytokine and HLA genes are associated with allergies, autoimmunity and neurodegeneration (ND). Samples from 131 African-American children (71 males; 60 females) in the Mechanistic Indicators of Childhood Asthma (MICA) study were used to determine SNPs of IL-4, IL...

Origin of the polymorphism of the involucrin gene in Asians.

PubMed Central

Djian, P; Delhomme, B; Green, H

1995-01-01

The involucrin gene, encoding a protein of the terminally differentiated keratinocyte, is polymorphic in the human. There is polymorphism of marker nucleotides a two positions in the coding region, and there are over eight polymorphic forms based on the number and kind of 10-codon tandem repeats in that part of the coding region most recently added in the human lineage. The involucrin alleles of Caucasians and Africans differ in both nucleotides and repeat patterns. We show that the involucrin alleles of East Asians (Chinese and Japanese) can be divided into two populations according to whether they possess the two marker nucleotides typical of Africans or Caucasians. The Asian population bearing Caucasian-type marker nucleotides has repeat patterns similar to those of Caucasians, whereas Asians bearing African-type marker nucleotides have repeat patterns that resemble those of Africans more than those of Caucasians. The existence of two populations of East Asian involucrin alleles gives support for the existence of a Eurasian stem lineage from which Caucasians and a part of the Asian population originated. PMID:7762559

Association of ABCB1 genetic variants with renal function in Africans and in Caucasians

PubMed Central

Bochud, Murielle; Eap, Chin B; Maillard, Marc; Johnson, Toby; Vollenweider, Peter; Bovet, Pascal; Elston, Robert C; Bergmann, Sven; Beckmann, Jacques S; Waterworth, Dawn M; Mooser, Vincent; Gabriel, Anne; Burnier, Michel

2008-01-01

Background The P-glycoprotein, encoded by the ABCB1 gene, is expressed in human endothelial and mesangial cells, which contribute to control renal plasma flow and glomerular filtration rate. We investigated the association of ABCB1 variants with renal function in African and Caucasian subjects. Methods In Africans (290 subjects from 62 pedigrees), we genotyped the 2677G>T and 3435 C>T ABCB1 polymorphisms. Glomerular filtration rate (GFR) was measured using inulin clearance and effective renal plasma flow (ERPF) using para-aminohippurate clearance. In Caucasians (5382 unrelated subjects), we analyzed 30 SNPs located within and around ABCB1, using data from the Affymetrix 500 K chip. GFR was estimated using the simplified Modification of the Diet in Renal Disease (MDRD) and Cockcroft-Gault equations. Results In Africans, compared to the reference genotype (GG or CC), each copy of the 2677T and 3435T allele was associated, respectively, with: GFR higher by 10.6 ± 2.9 (P < 0.001) and 4.4 ± 2.3 (P = 0.06) mL/min; ERPF higher by 47.5 ± 11.6 (P < 0.001) and 28.1 ± 10.5 (P = 0.007) mL/min; and renal resistances lower by 0.016 ± 0.004 (P < 0.001) and 0.011 ± 0.004 (P = 0.004) mm Hg/mL/min. In Caucasians, we identified 3 polymorphisms in the ABCB1 gene that were strongly associated with all estimates of GFR (smallest P value = 0.0006, overall P = 0.014 after multiple testing correction). Conclusion Variants of the ABCB1 gene were associated with renal function in both Africans and Caucasians and may therefore confer susceptibility to nephropathy in humans. If confirmed in other studies, these results point toward a new candidate gene for nephropathy in humans. PMID:18518969

A Common Variant in the Von Willebrand Factor Gene is Associated With Multiple Functional Consequences

PubMed Central

Vaidya, Dhananjay; Yanek, Lisa R.; Herrera-Galeano, J. Enrique; Mathias, Rasika A.; Moy, Taryn F.; Faraday, Nauder; Becker, Lewis C.; Becker, Diane M.

2010-01-01

Von Willebrand Factor (vWF) is a plasma protein involved in thrombosis and hemostasis [1]. We examined whether common single nucleotide polymorphisms (SNPs) in the vWF gene were associated with vWF levels and platelet aggregation-related functional consequences in1230 Whites and 837 African Americans in a cross-sectional family based genetic study of platelet function. From a high-density scan, 28 SNPs with a minor allele frequency > 5% in both races were tested for association using age and sex adjusted variance components analysis in MERLIN. SNP rs216321, with the strongest association with vWF levels in biracial metaanalysis (p=9.5×10−6, Whites–p=8.1×10−4, African Americans–p=3.6×10−3), encoding a R852Q substitution in the D’D3 protein domain, demonstrated negative association with plasma vWF. The R852Q variant was recessively associated with 15.5% lower collagen-induced platelet aggregation adjusting for dose-response relationship (p=0.010, vWF-level adjusted p=0.003). Each copy of the R852Q variant was additively associated with 31% higher FVIII levels (p=0.039, vWF-adjusted p=0.033). In conclusion, this common missense polymorphism appears to have pleiotropic functional consequences. PMID:20941784

Hereditary polymorphic light eruption of American Indians: occurrence in non-Indians with polymorphic light eruption.

PubMed

Fusaro, R M; Johnson, J A

1996-04-01

Hereditary polymorphic light eruption (HPLE) occurs unique ly in the American Indian and Inuit and exhibits autosomal dominant transmission. Because the cutaneous expression of HPLE resembles that of polymorphic light eruption (PLE) and because many non-Indians in the United States have American Indian heritage, some instances of PLE may actually be HPLE. Our purpose was to determine whether non-Indian patients with PLE have characteristics suggestive of HPLE. We surveyed in Nebraska 25 European-Caucasian and 36 African-American patients with PLE for American Indian heritage and photosensitive relatives. Nonphotosensitive subjects (52 Caucasians and 40 African Americans) were surveyed for American Indian heritage. American Indian heritage occurred in 11 Caucasian patients (44%); of those, seven (64%) had photosensitive relatives. Likewise, 29 African Americans (81%) had American Indian heritage; 19 (66%) of those had photosensitive relatives. American Indian heritage occurred in 10 Caucasian control subjects (19%) and in 34 African-American control subjects (85%). If American Indian heritage and a family history of photosensitivity are definitive for HPLE, seven (28%) of our Caucasian patients and 19 (53%) of our African-American patients have HPLE rather than PLE. We urge physicians who suspect PLE in non-Indians to ask about American Indian heritage and photosensitive relatives and to screen their present patients with PLE for such characteristics.

Association of SLC11A1 with tuberculosis interactions with NOS2A and TLR2 in African-Americans and Caucasians

PubMed Central

Velez, D.R.; Hulme, W.F.; Myers, J.L.; Stryjewski, M.E.; Abbate, E.; Estevan, R.; Patillo, S.G.; Gilbert, J.R.; Hamilton, C.D.; Scott, W.K.

2010-01-01

SETTING Host defense factors may influence the development of active tuberculosis (TB). OBJECTIVE To test variants in solute carrier family 11A, member 1 (SLC11A1), for an association with TB. METHODS A mixed case-control study of TB cases, relatives or close contact controls, consisting of 474 African-Americans (243 families) and 381 Caucasians (192 families), examined 13 SLC11A1 polymorphisms for association with pulmonary TB using generalized estimating equations adjusting for age and gender. RESULTS Two associations were observed in Caucasians (rs3731863, P = 0.03, and rs17221959, P = 0.04) and one in African-Americans (rs3731865, P = 0.05). Multilocus analyses between polymorphisms in SLC11A1 and 11 TB candidate genes detected interactions between SLC11A1 and inducible nitric oxide synthase (NOS2A) in Caucasians (rs3731863 [SLC11A1] × rs8073782 [NOS2A], P = 0.009; rs3731863 [SLC11A1] × rs17722851 [NOS2A], P = 0.007) and toll-like receptor 2 (TLR2) in African-Americans (rs3731865 [SLC11A1] x rs1816702, P = 0.005). CONCLUSIONS No association was detected with 5′(GT)n promoter polymorphism previously associated with lower SLC11A1 expression, rs17235409 (D543N), or rs17235416 (3′ TGTG insertion/deletion polymorphism). SLC11A1 polymorphism rs3731865 was associated with TB in African-Americans, consistent with previous findings in West Africans. These results suggest that variants in SLC11A1 increase susceptibility to pulmonary TB and interact with other variants that differ by race. PMID:19723394

Genome-Wide Association Study to Identify Single Nucleotide Polymorphisms (SNPs) Associated With the Development of Erectile Dysfunction in African-American Men After Radiotherapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kerns, Sarah L.; Ostrer, Harry; Stock, Richard

2010-12-01

Purpose: To identify single nucleotide polymorphisms (SNPs) associated with erectile dysfunction (ED) among African-American prostate cancer patients treated with external beam radiation therapy. Methods and Materials: A cohort of African-American prostate cancer patients treated with external beam radiation therapy was observed for the development of ED by use of the five-item Sexual Health Inventory for Men (SHIM) questionnaire. Final analysis included 27 cases (post-treatment SHIM score {<=}7) and 52 control subjects (post-treatment SHIM score {>=}16). A genome-wide association study was performed using approximately 909,000 SNPs genotyped on Affymetrix 6.0 arrays (Affymetrix, Santa Clara, CA). Results: We identified SNP rs2268363, locatedmore » in the follicle-stimulating hormone receptor (FSHR) gene, as significantly associated with ED after correcting for multiple comparisons (unadjusted p = 5.46 x 10{sup -8}, Bonferroni p = 0.028). We identified four additional SNPs that tended toward a significant association with an unadjusted p value < 10{sup -6}. Inference of population substructure showed that cases had a higher proportion of African ancestry than control subjects (77% vs. 60%, p = 0.005). A multivariate logistic regression model that incorporated estimated ancestry and four of the top-ranked SNPs was a more accurate classifier of ED than a model that included only clinical variables. Conclusions: To our knowledge, this is the first genome-wide association study to identify SNPs associated with adverse effects resulting from radiotherapy. It is important to note that the SNP that proved to be significantly associated with ED is located within a gene whose encoded product plays a role in male gonad development and function. Another key finding of this project is that the four SNPs most strongly associated with ED were specific to persons of African ancestry and would therefore not have been identified had a cohort of European ancestry been screened. This study demonstrates the feasibility of a genome-wide approach to investigate genetic predisposition to radiation injury.« less

Sequence polymorphism at the human apolipoprotein AII gene ( APOA2): unexpected deficit of variation in an African-American sample.

PubMed

Fullerton, Stephanie M; Clark, Andrew G; Weiss, Kenneth M; Taylor, Scott L; Stengård, Jari H; Salomaa, Veikko; Boerwinkle, Eric; Nickerson, Deborah A

2002-07-01

A 3.3-kb region, encompassing the APOA2 gene and 2 kb of 5' and 3' flanking DNA, was re-sequenced in a "core" sample of 24 individuals, sampled without regard to the health from each of three populations: African-Americans from Jackson (Miss., USA), Europeans from North Karelia (Finland), and non-Hispanic European-Americans from Rochester, (Minn., USA). Fifteen variable sites were identified (14 SNPs and one multi-allelic microsatellite, all silent), and these sites segregated as 18 sequence haplotypes (or nine, if SNPs only are considered). The haplotype distribution in the core African-American sample was unusual, with a deficit of particular haplotypes compared with those found in the other two samples, and a significantly (P<0.05) low level of nucleotide diversity relative to patterns of polymorphism and divergence at other human loci. Six of the 14 SNPs, whose variation captured the haplotype structure of the core data, were then genotyped by oligonucleotide ligation assay in an additional 2183 individuals from the same three populations (n=843, n=452, and n=888, respectively). All six sites varied in each of the larger "epidemiological" samples, and together, they defined 19 SNP haplotypes, seven with relative frequencies greater than 1% in the total sample; all of these common haplotypes had been identified earlier in the core re-sequencing survey. Here also, the African-American sample showed significantly lower SNP heterozygosity and haplotype diversity than the other two samples. The deficit of polymorphism is consistent with a population-specific non-neutral increase in the relative frequency of several haplotypes in Jackson.

Association of Neuroantibodies(NAB) with Glutathione-S-Tranferase(GST) Isozyme Polymorphisms(SNP) in African-American Children with Heavy Metal Exposure

EPA Science Inventory

Polymorphisms in GST isozymes have implications in heavy metal accumulation, neurodegeneration, and immune-mediated disease. Blood cell DNA and sera from 131 African-American children were used to determine GST Pi [rs947895 (C>A), rs17593068 (G>T), rs6591256 (A>G), rs187...

Frequency of genetic polymorphisms of PXR gene in the Brazilian population.

PubMed

Moreira, Ricardo P P; Jorge, Alexander A L; Mendonca, Berenice B; Bachega, Tânia A S S

2011-01-01

PXR polymorphisms have been implicated in modulating CYP3A4 and PXR expression, potentially accounting for interindividual differences in drug metabolism. The prevalence of PXR polymorphisms varies among ethnic groups and data on the allelic distribution in the highly mixed Brazilian population is lacking. The aim of this study was to analyze genetic variations in the PXR gene in Brazilians and to compare the results to other ethnic groups. DNA samples from 117 healthy Brazilians underwent PCR amplification and sequencing. Eleven polymorphisms were identified, 3 of which are highly associated with differences in CYP3A4 expression. We also identified 1 new synonymous variant in 1.3% of the alleles. Among the functional polymorphisms, -25913 C>T and -6994T>C occurred at a higher frequency comparedtothe Africanalleles (p < 0.05) but at a lower frequency compared to Caucasian alleles. The 8055 C>T allele was found at a similar frequency to those described in Caucasians and Africans (p > 0.05). We observed that functional variants of the PXR were frequent in our sample of the Brazilian population. Our results suggest that PXR gene variants may be of interest in pharmacogenetic studies involving Brazilians.

The 5-HTTLPR polymorphism moderates the effect of stressful life events on drinking behavior in college students of African descent.

PubMed

Kranzler, Henry R; Scott, Denise; Tennen, Howard; Feinn, Richard; Williams, Carla; Armeli, Stephen; Taylor, Robert E; Briggs-Gowan, Margaret J; Covault, Jonathan

2012-07-01

Covault et al. [Covault et al. (2007); Biol Psychiatry 61(5): 609-616] reported that the common functional polymorphism, 5-HTTLPR, in the serotonin transporter gene moderated the association between past-year stressful events and daily reports of drinking in a sample of European-American (EA) college students. We examined this effect in college students of African descent. Students recruited at a Historically Black University (n = 564) completed web-based measures of past-year stressful life experiences and daily reports of drinking and heavy drinking over a 30-day period. Participants were genotyped for the tri-allelic 5-HTTLPR polymorphism and dichotomized as low-activity S' allele carriers or high-activity L' homozygotes. Generalized linear models were used to examine the effects of life stress, genotype, and their interaction on the two drinking measures. In students who completed 15 or more daily surveys (n = 393), there was a significant interaction of past-year stressful events, 5-HTTLPR genotype, and gender on the number of drinking days (P = 0.002). Similar findings were obtained in relation to heavy drinking days (P = 0.007). Men showed a main effect of past-year stressful events on both drinking outcomes (P's < 0.001), but no main or moderator effects of genotype. In women, the S' allele moderated the impact of past-year life stressors on the frequency of drinking and heavy drinking days (P's < 0.001). In college students of African descent, past-year stressful events were associated with more frequent drinking and heavy drinking, an effect that was moderated by the 5-HTTLPR polymorphism. However, in contrast to the findings in EA students, in the current sample, 5-HTTLPR moderated the association only among women. Copyright © 2012 Wiley Periodicals, Inc.

The 5-HTTLPR Polymorphism Moderates the Effect of Stressful Life Events on Drinking Behavior in College Students of African Descent

PubMed Central

Kranzler, Henry R.; Scott, Denise; Tennen, Howard; Feinn, Richard; Williams, Carla; Armeli, Stephen; Taylor, Robert E.; Briggs-Gowan, Margaret J.; Covault, Jonathan

2012-01-01

Background Covault et al. (2007) reported that the common functional polymorphism, 5-HTTLPR, in the serotonin transporter gene moderated the association between past-year stressful events and daily reports of drinking in a sample of European-American (EA) college students. We examined this effect in college students of African descent. Methods Students recruited at a Historically Black University (n=564) completed web-based measures of past-year stressful life experiences and daily reports of drinking and heavy drinking over a 30-day period. Participants were genotyped for the tri-allelic 5-HTTLPR polymorphism and dichotomized as low-activity S’ allele carriers or high-activity L’ homozygotes. Generalized linear models were used to examine the effects of life stress, genotype, and their interaction on the two drinking measures. Results In students who completed 15 or more daily surveys (n=393), there was a significant interaction of past-year stressful events, 5-HTTLPR genotype, and gender on the number of drinking days (p=0.002). Similar findings were obtained in relation to heavy drinking days (p=0.007). Men showed a main effect of past-year stressful events on both drinking outcomes (p’s<0.001), but no main or moderator effects of genotype. In women, the S’ allele moderated the impact of past-year life stressors on the frequency of drinking and heavy drinking days (p’s<0.001). Conclusions In college students of African descent, past-year stressful events were associated with more frequent drinking and heavy drinking, an effect that was moderated by the 5-HTTLPR polymorphism. However, in contrast to the findings in EA students, in the current sample, 5-HTTLPR moderated the association only among women. PMID:22488930

The DRD2 Taq1A A1 Allele May Magnify the Risk of Alzheimer's in Aging African-Americans.

PubMed

Blum, Kenneth; Badgaiyan, Rajendra D; Dunston, Georgia M; Baron, David; Modestino, Edward J; McLaughlin, Thomas; Steinberg, Bruce; Gold, Mark S; Gondré-Lewis, Marjorie C

2017-09-30

Alzheimer's disease is an irreversible, progressive brain disorder that slowly destroys cognitive skills and the ability to perform the simplest tasks. More than 5 million Americans are afflicted with Alzheimer's; a disorder which ranks third, just behind heart disease and cancer, as a cause of death for older people. With no real cure and in spite of enormous efforts worldwide, the disease remains a mystery in terms of treatment. Importantly, African-Americans are two times as likely as Whites to develop late-onset Alzheimer's disease and less likely to receive timely diagnosis and treatment. Dopamine function is linked to normal cognition and memory and carriers of the DRD2 Taq1A A1 allele have significant loss of D2 receptor density in the brain. Recent research has shown that A1 carriers have worse memory performance during long-term memory (LTM) updating, compared to non-carriers or A2-carriers. A1carriers also show less blood oxygen level-dependent (BOLD) activation in the left caudate nucleus which is important for LTM updating. This latter effect was only seen in older adults, suggesting magnification of genetic effects on brain functioning in the elderly. Moreover, the frequency of the A1 allele is 0.40 in African-Americans, with an approximate prevalence of the DRD2 A1 allele in 50% of an African-American subset of individuals. This is higher than what is found in a non-screened American population (≤ 28%) for reward deficiency syndrome (RDS) behaviors. Based on DRD2 known genetic polymorphisms, we hypothesize that the DRD2 Taq1A A1 allele magnifies the risk of Alzheimer's in aging African-Americans. Research linking this high risk for Alzheimer's in the African-American population, with DRD2/ANKK1-TaqIA polymorphism and neurocognitive deficits related to LTM, could pave the way for novel, targeted pro-dopamine homeostatic treatment.

Interethnic diversity of the CD209 (rs4804803) gene promoter polymorphism in African but not American sickle cell disease.

PubMed

Noble, Jenelle A; Duru, Kimberley C; Guindo, Aldiouma; Yi, Li; Imumorin, Ikhide G; Diallo, Dapa A; Thomas, Bolaji N

2015-01-01

Elucidating the genomic diversity of CD209 gene promoter polymorphism could assist in clarifying disease pathophysiology as well as contribution to co-morbidities. CD209 gene promoter polymorphism has been shown to be associated with susceptibility to infection. We hypothesize that CD209 mutant variants occur at a higher frequency among Africans and in sickle cell disease. We analyzed the frequency of the CD209 gene (rs4804803) in healthy control and sickle cell disease (SCD) populations and determined association with disease. Genomic DNA was extracted from blood samples collected from 145 SCD and 231 control Africans (from Mali), 331 SCD and 379 control African Americans and 159 Caucasians. Comparative analysis among and between groups was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Per ethnic diversification, we found significant disparity in genotypic (23.4% versus 16.9% versus 3.2%) and allelic frequencies (48.7% versus 42.1% versus 19.8%) of the homozygote mutant variant of the CD209 (snp 309A/G) gene promoter between Africans, African Americans and Caucasians respectively. Comparative evaluation between disease and control groups reveal a significant difference in genotypic (10.4% versus 23.4%; p = 0.002) and allelic frequencies (39.7% versus 48.7%; p = 0.02) of the homozygote mutant variant in African SCD and healthy controls respectively, an observation that is completely absent among Americans. Comparing disease groups, we found no difference in the genotypic (p = 0.19) or allelic (p = 0.72) frequencies of CD209 homozygote mutant variant between Africans and Americans with sickle cell disease. The higher frequency of CD209 homozygote mutant variants in the African control group reveals a potential impairment of the capacity to mount an immune response to infectious diseases, and possibly delineate susceptibility to or severity of infectious co-morbidities within and between groups.

Interethnic diversity of the CD209 (rs4804803) gene promoter polymorphism in African but not American sickle cell disease

PubMed Central

Noble, Jenelle A.; Duru, Kimberley C.; Guindo, Aldiouma; Yi, Li; Imumorin, Ikhide G.; Diallo, Dapa A.

2015-01-01

Elucidating the genomic diversity of CD209 gene promoter polymorphism could assist in clarifying disease pathophysiology as well as contribution to co-morbidities. CD209 gene promoter polymorphism has been shown to be associated with susceptibility to infection. We hypothesize that CD209 mutant variants occur at a higher frequency among Africans and in sickle cell disease. We analyzed the frequency of the CD209 gene (rs4804803) in healthy control and sickle cell disease (SCD) populations and determined association with disease. Genomic DNA was extracted from blood samples collected from 145 SCD and 231 control Africans (from Mali), 331 SCD and 379 control African Americans and 159 Caucasians. Comparative analysis among and between groups was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Per ethnic diversification, we found significant disparity in genotypic (23.4% versus 16.9% versus 3.2%) and allelic frequencies (48.7% versus 42.1% versus 19.8%) of the homozygote mutant variant of the CD209 (snp 309A/G) gene promoter between Africans, African Americans and Caucasians respectively. Comparative evaluation between disease and control groups reveal a significant difference in genotypic (10.4% versus 23.4%; p = 0.002) and allelic frequencies (39.7% versus 48.7%; p = 0.02) of the homozygote mutant variant in African SCD and healthy controls respectively, an observation that is completely absent among Americans. Comparing disease groups, we found no difference in the genotypic (p = 0.19) or allelic (p = 0.72) frequencies of CD209 homozygote mutant variant between Africans and Americans with sickle cell disease. The higher frequency of CD209 homozygote mutant variants in the African control group reveals a potential impairment of the capacity to mount an immune response to infectious diseases, and possibly delineate susceptibility to or severity of infectious co-morbidities within and between groups. PMID:25755928

Vitamin D Levels and Related Genetic Polymorphisms, Sun Exposure, Skin Color, and Risk of Aggressive Prostate Cancer

DTIC Science & Technology

2012-07-01

for our specific aims. 15. SUBJECT TERMS vitamin D deficiency, prostate cancer, health disparities, African American 16. SECURITY CLASSIFICATION OF...ler.reb (If - 0.43 wen aJECia6!d with ~ iota re.icleaa~ in tbe lropi.:. (~- 5.60, p- 114), &t:.ry vibnoio D iobsb @- 0.01, p- ,OJ); IIILd supplmu1Ji

A Culturally-Specific Dance Intervention to Increase Functional Capacity in African American Women

PubMed Central

Murrock, Carolyn J.; Gary, Faye A.

2013-01-01

This study examined a culturally-specific dance intervention on functional capacity in African American women at three time points. The intervention was two times per week for 8 weeks using two African American churches randomly assigned to either the experimental or comparison group, had 126 participants, ages 36–82 years. Analysis of covariance revealed that both groups improved over time and the only significant difference between groups was at 18 weeks. The increase at 18 weeks in the experimental group remained when controlling for baseline covariates. This study supported culturally-specific dance as an intervention to improve functional capacity in African American women. PMID:19202718

A culturally-specific dance intervention to increase functional capacity in African American women.

PubMed

Murrock, Carolyn J; Gary, Faye A

2008-01-01

This study examined a culturally-specific dance intervention on functional capacity in African American women at three time points. The intervention was two times per week for 8 weeks using two African American churches randomly assigned to either the experimental or comparison group, had 126 participants, ages 36-82 years. Analysis of covariance revealed that both groups improved over time and the only significant difference between groups was at 18 weeks. The increase at 18 weeks in the experimental group remained when controlling for baseline covariates. This study supported culturally-specific dance as an intervention to improve functional capacity in African American women.

5-HTTLPR polymorphism: analysis in South African autistic individuals.

PubMed

Arieff, Zainunisha; Kaur, Mandeep; Gameeldien, Hajirah; van der Merwe, Lize; Bajic, Vladimir B

2010-06-01

The serotonin transporter promoter length polymorphism (5-hydroxytryptamine transporter length polymorphism; 5-HTTLPR) has long been implicated in autism and other psychiatric disorders. The use of selective serotonin reuptake inhibitors (SSRIs) has a positive effect on treating some symptoms of autism. The effects of these drugs vary in individuals because of the presence of the S or L allele of 5-HTTLPR. Studies performed on various autistic populations have found different allele frequencies for the L and S alleles. Allele frequencies and genotypes of the South African autistic populations (African, mixed, and Caucasian) were compared with matching South African ethnic control populations. The *S/*S genotype was found to be highly significantly associated with all the South African autistic ethnic populations. In the South African African population the *S/*S genotype was present in 7 (33%) of the autistic individuals but in none of the control subjects, yielding infinitely large odds of developing autism. The odds of developing autism with the *S/*S genotype compared to the *L/*L genotype increased 10.15-fold in the South African mixed group and 2.74-fold in the South African Caucasian population. The allele frequency of the South African autistic population was also compared with studies of other autistic populations around the world, and highly significant differences were found with the Japanese, Korean, and Indian population groups. The difference was not significant for the French, German, Israeli, Portuguese, and American groups. This is the first South African study of autistic individuals of different ethnic backgrounds that shows significant differences in allele and genotype frequencies of 5-HTTLPR. The results of this study open new avenues for investigating the role of transmission of the L and S alleles in families with autism in South Africa.

Increased risk of incident stroke associated with the cyclooxygenase 2 (COX-2) G-765C polymorphism in African-Americans: the Atherosclerosis Risk in Communities Study.

PubMed

Kohsaka, Shun; Volcik, Kelly A; Folsom, Aaron R; Wu, Kenneth K; Ballantyne, Christie M; Willerson, James T; Boerwinkle, Eric

2008-02-01

A hallmark feature of atherosclerosis is inflammation mediated by prostaglandins (PGs) catalyzed by the enzyme cyclooxygenase (COX). The present study explored whether the COX-2 G-765C polymorphism contributes to increased incidence of coronary heart disease (CHD) or stroke in the large prospective Atherosclerosis Risk in Communities (ARIC) Study. Incidences of CHD and stroke were identified through annual follow-up and hospital and death certificate surveillance. The study included 1488 incident CHD and 527 stroke events after an average of 14 years of follow-up. The frequency of the -765C variant allele was markedly different between African-Americans and whites, therefore all analyses were performed separately by race. Due to the small number of persons with the -765CC genotype, heterozygous and homozygous variant genotypes were combined for this analysis. The COX-2 G-765C polymorphism was not a significant predictor of CHD in either racial group, but it was a significant predictor of incident stroke in African-Americans. After adjustment for age and gender, the hazard rate ratio for developing stroke for the CG+CC genotypes relative to the GG genotype was 1.34 (95% confidence interval [CI] 1.03-1.74, P=0.03) in African-Americans. This result was essentially unchanged when established predictors such as smoking, diabetes and hypertension were added to the model (HRR 1.34, 95%CI 1.03-1.76, P=0.03). We have found the COX-2 G-765C polymorphism to be a risk factor for incident stroke in African-Americans. This study provides additional evidence for utilizing inflammation-related genetic polymorphisms for identifying individuals at increased risk for stroke.

Can immune-related genotypes illuminate the immunopathogenesis of cytomegalovirus disease in human immunodeficiency virus-infected patients?

PubMed

Affandi, Jacquita S; Aghafar, Zayd K A; Rodriguez, Benigno; Lederman, Michael M; Burrows, Sally; Senitzer, David; Price, Patricia

2012-02-01

Most human immunodeficiency virus (HIV) patients are seropositive for cytomegalovirus (CMV) but a smaller proportion experience end-organ disease. This observation may reflect variations in genes affecting inflammatory and natural killer cell responses. DNA samples were collected from 240 HIV-infected patients followed at the University Hospitals/Case Medical Center (Cleveland, OH) between 1993 and 2008. Seventy-eight patients (African Americans = 41, Caucasians = 37) experienced CMV disease. Genotypes were determined using allele-specific fluorescent probes or multiplex polymerase chain reaction sequence-specific primers. IL12B3'UTR*(1) and SLC11A1 D543N*(1,2) were associated with CMV disease in African American patients (p = 0.04 and p = 0.02, respectively). IL10-1082*(1,2) and LILRB1 I142T*(1) were associated with CMV disease in Caucasians (p = 0.02 and p = 0.07, respectively). DARC T-46C*(1) and CD14 C-159T*(2) were associated with low nadir CD4(+) T cell counts in African American patients (p = 0.002 and p = 0.01, respectively). Caucasian patients carrying TNFA-308*2, TNFA-1031*(2), IL2-330*(1), CCL2-2518*(2), or LILRB1 I142T*(1) had significantly lower nadir CD4(+) T cells in a bootstrapped multivariable model (p = 0.006-0.02). In general, polymorphisms associated with CMV disease and CD4(+) T cell counts were distinct in Caucasian and African American patients in the United States. The LILRB1 I142T polymorphism was associated with both CMV disease and low nadir CD4(+) T cell counts in Caucasians, but the clearest determinant of low nadir CD4(+) T cell count in African American patients was DARC T-46C. Copyright © 2012 American Society for Histocompatibility and Immunogenetics. All rights reserved.

Race, Gender, and Genetic Polymorphism Contribute to Variability in Acetaminophen Pharmacokinetics, Metabolism, and Protein-Adduct Concentrations in Healthy African-American and European-American Volunteers.

PubMed

Court, Michael H; Zhu, Zhaohui; Masse, Gina; Duan, Su X; James, Laura P; Harmatz, Jerold S; Greenblatt, David J

2017-09-01

Over 30 years ago, black Africans from Kenya and Ghana were shown to metabolize acetaminophen faster by glucuronidation and slower by oxidation compared with white Scottish Europeans. The objectives of this study were to determine whether similar differences exist between African-Americans and European-Americans, and to identify genetic polymorphisms that could explain these potential differences. Acetaminophen plasma pharmacokinetics and partial urinary metabolite clearances via glucuronidation, sulfation, and oxidation were determined in healthy African-Americans (18 men, 23 women) and European-Americans (34 men, 20 women) following a 1-g oral dose. There were no differences in acetaminophen total plasma, glucuronidation, or sulfation clearance values between African-Americans and European-Americans. However, median oxidation clearance was 37% lower in African-Americans versus European-Americans (0.57 versus 0.90 ml/min per kilogram; P = 0.0001). Although acetaminophen total or metabolite clearance values were not different between genders, shorter plasma half-life values (by 11-14%; P < 0.01) were observed for acetaminophen, acetaminophen glucuronide, and acetaminophen sulfate in women versus men. The UGT2B15*2 polymorphism was associated with variant-allele-number proportional reductions in acetaminophen total clearance (by 15-27%; P < 0.001) and glucuronidation partial clearance (by 23-48%; P < 0.001). UGT2B15 *2/*2 genotype subjects also showed higher acetaminophen protein-adduct concentrations than *1/*2 (by 42%; P = 0.003) and *1/*1 (by 41%; P = 0.003) individuals. Finally, CYP2E1 *1D/*1D genotype African-Americans had lower oxidation clearance than *1C/*1D (by 42%; P = 0.041) and *1C/*1C (by 44%; P = 0.048) African-Americans. Consequently, African-Americans oxidize acetaminophen more slowly than European-Americans, which may be partially explained by the CYP2E1*1D polymorphism. UGT2B15*2 influences acetaminophen pharmacokinetics in both African-Americans and European-Americans. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Co-evolution of Human Leukocyte Antigen (HLA) Class I Ligands with Killer-Cell Immunoglobulin-Like Receptors (KIR) in a Genetically Diverse Population of Sub-Saharan Africans

PubMed Central

Norman, Paul J.; Hollenbach, Jill A.; Nemat-Gorgani, Neda; Guethlein, Lisbeth A.; Hilton, Hugo G.; Pando, Marcelo J.; Koram, Kwadwo A.; Riley, Eleanor M.; Abi-Rached, Laurent; Parham, Peter

2013-01-01

Interactions between HLA class I molecules and killer-cell immunoglobulin-like receptors (KIR) control natural killer cell (NK) functions in immunity and reproduction. Encoded by genes on different chromosomes, these polymorphic ligands and receptors correlate highly with disease resistance and susceptibility. Although studied at low-resolution in many populations, high-resolution analysis of combinatorial diversity of HLA class I and KIR is limited to Asian and Amerindian populations with low genetic diversity. At the other end of the spectrum is the West African population investigated here: we studied 235 individuals, including 104 mother-child pairs, from the Ga-Adangbe of Ghana. This population has a rich diversity of 175 KIR variants forming 208 KIR haplotypes, and 81 HLA-A, -B and -C variants forming 190 HLA class I haplotypes. Each individual we studied has a unique compound genotype of HLA class I and KIR, forming 1–14 functional ligand-receptor interactions. Maintaining this exceptionally high polymorphism is balancing selection. The centromeric region of the KIR locus, encoding HLA-C receptors, is highly diverse whereas the telomeric region encoding Bw4-specific KIR3DL1, lacks diversity in Africans. Present in the Ga-Adangbe are high frequencies of Bw4-bearing HLA-B*53:01 and Bw4-lacking HLA-B*35:01, which otherwise are identical. Balancing selection at key residues maintains numerous HLA-B allotypes having and lacking Bw4, and also those of stronger and weaker interaction with LILRB1, a KIR-related receptor. Correspondingly, there is a balance at key residues of KIR3DL1 that modulate its level of cell-surface expression. Thus, capacity to interact with NK cells synergizes with peptide binding diversity to drive HLA-B allele frequency distribution. These features of KIR and HLA are consistent with ongoing co-evolution and selection imposed by a pathogen endemic to West Africa. Because of the prevalence of malaria in the Ga-Adangbe and previous associations of cerebral malaria with HLA-B*53:01 and KIR, Plasmodium falciparum is a candidate pathogen. PMID:24204327

Molecular defects leading to human complement component C6 deficiency in an African-American family

PubMed Central

Zhu, Z-B; Totemchokchyakarn, K; Atkinson, T P; Volanakis, J E

1998-01-01

Complement component C6 deficiency (C6D) was diagnosed in a 16-year-old African-American male with meningococcal meningitis. The patient's father and two brothers also had C6D, but gave no history of meningitis or other neisserial infection. By using exon-specific polymerase chain reaction (PCR)/single-strand conformation polymorphism as a screening step and nucleotide sequencing of target exons, we determined that the proband was a compound heterozygote for two C6 gene mutations. The first, 1195delC located in exon 7, is a novel mutation, while the second, 1936delG in exon 12, has been described before to cause C6D in an unrelated African-American individual. Both mutations result in premature termination codons and C6 null alleles. Allele-specific PCR indicated that the proband's two brothers also inherited the 1195delC mutation from their heterozygous mother and the 1936delG mutation from their homozygous father. PMID:9472666

IL-10 and IL-12B gene polymorphisms in a multiethnic Malaysian population.

PubMed

Sam, S S; Teoh, B T; AbuBakar, S

2015-04-13

Inheritance of polymorphisms in the interleukin (IL)-10 promoter and IL-12B genes, which influence cytokine production and activities, may define the balance in T helper response in infection and autoimmune diseases. In the present study, we investigated the distribution of the IL-10 promoter and IL-12B gene polymorphisms in a multiethnic Malaysian population. Overall, our findings suggest that the IL-12B and IL-10 -592 genotypes were distributed homogenously across all major ethnic groups, including Malays, Chinese, and Indians, except for polymorphisms at IL-10 -1082. At this gene locus, the ethnic Chinese showed a significantly lower allele frequency of -1082G (2.1%) compared to the Malay (12.2%) and Indian (15.3%) populations. Results for the IL-12B and IL-10 gene polymorphisms were consistent with those reported for the Asian population, but markedly different from those of the African and Caucasian populations. Our findings suggest that there are specific genetic variations between different ethnic groups, which should be examined in all gene population-based association studies.

[Efficiency of 27-plex single nucleotide polymorphism multiplex system for ancestry inference in different populations].

PubMed

Feng, Xing-Ling; Sun, Qi-Fan; Liu, Hong; Wei, Yi-Liang; DU, Wei-An; Li, Cai-Xia; Chen, Ling; Liu, Chao

2016-04-20

To validate the efficiency of 27-plex single nucleotide polymorphism (SNP) multiplex system for ancestry inference. The 27-plex SNP system was validated for its sensitivity and species specificity. A total of 533 samples were collected from African, Southern Chinese Han, China's ethic minorities (Yi, Hui, Miao, Tibet, and Uygur), European, Central Asian, Western Asian, Southern Asian, Southeast Asian and South American populations for clustering analysis of the genotypes by citing 3 representative continental ancestral groups [East Asia (CHB), Europe (CEU), and Africa (YRI)] from HapMap database. The system sensitivity is 0.125 ng. Twenty and six genotypes were detected in chimpanzee and monkeys, respectively. Except in rs10496971, no more products were found in other animals. The system was capable of differentiating intercontinental populations but not of distinguishing between East Asian and Southeast Asian population or between Southern Chinese Han population and Chinese Ethnic populations (Hui, Miao, Yi and Tibet). This system achieved a 100% accuracy for intercontinental population source inference for 46 blind test samples. 27-plex SNPs multiplex system has a high sensitivity and species specificity and can correctly differentiate the ancestry origins of individuals from African, European and East Asian for criminal case investigation. But this system is not capable of distinguishing subpopulation groups and more specific ancestry-informative markers are needed to improve its recognition of Southeast Asian and Chinese ethnic populations.

A pharmacogenetic study of CD4 recovery in response to HIV antiretroviral therapy in two South African population groups.

PubMed

Parathyras, John; Gebhardt, Stefan; Hillermann-Rebello, Renate; Grobbelaar, Nelis; Venter, Mauritz; Warnich, Louise

2009-05-01

South Africa, like many other Southern African countries, has one of the highest HIV infection rates in the world and many individuals consequently receive antiretroviral therapy (ART). However, knowledge regarding (i) the prevalence of functional single nucleotide polymorphisms (SNPs) in pharmacologically relevant genes, and (ii) variance in pharmacotherapy both within and between different populations and ethnic groups is limited. The aim of this study was to determine whether selected polymorphisms in cytochrome P450 (CYP) genes (CYP2B6 and CYP3A4) and the multidrug-resistance 1 (ABCB1) gene underlie altered antiretroviral (ARV) drug response in two South African populations. DNA samples from 182 HIV-positive individuals of Mixed-Ancestry and Xhosa ethnicity on ART were genotyped for the A-392G SNP in CYP3A4, the G516T and A785G SNPs in CYP2B6, and the T-129C, C1236T, G2677T/A and C3435T SNPs in ABCB1. Univariate two-way analysis of variance (ANOVA) testing revealed no apparent effect of ethnicity on immune recovery (in terms of CD4-cell count) in response to ART. Univariate one-way ANOVA testing revealed a discernible effect of genotype on immune recovery in the cases of the T-129C (P=0.03) and G2677A (P<0.01) polymorphisms in the ABCB1 gene. This study serves as a basis for better understanding and possible prediction of pharmacogenetic risk profiles and drug response in individuals and ethnic groups in South Africa.

Primate TNF Promoters Reveal Markers of Phylogeny and Evolution of Innate Immunity

PubMed Central

Baena, Andres; Ligeiro, Filipa; Diop, Ousmane M.; Brieva, Claudia; Gagneux, Pascal; O'Brien, Stephen J.; Ryder, Oliver A.; Goldfeld, Anne E.

2007-01-01

Background Tumor necrosis factor (TNF) is a critical cytokine in the immune response whose transcriptional activation is controlled by a proximal promoter region that is highly conserved in mammals and, in particular, primates. Specific single nucleotide polymorphisms (SNPs) upstream of the proximal human TNF promoter have been identified, which are markers of human ancestry. Methodology/Principal findings Using a comparative genomics approach we show that certain fixed genetic differences in the TNF promoter serve as markers of primate speciation. We also demonstrate that distinct alleles of most human TNF promoter SNPs are identical to fixed nucleotides in primate TNF promoters. Furthermore, we identify fixed genetic differences within the proximal TNF promoters of Asian apes that do not occur in African ape or human TNF promoters. Strikingly, protein-DNA binding assays and gene reporter assays comparing these Asian ape TNF promoters to African ape and human TNF promoters demonstrate that, unlike the fixed differences that we define that are associated with primate phylogeny, these Asian ape-specific fixed differences impair transcription factor binding at an Sp1 site and decrease TNF transcription induced by bacterial stimulation of macrophages. Conclusions/significance Here, we have presented the broadest interspecies comparison of a regulatory region of an innate immune response gene to date. We have characterized nucleotide positions in Asian ape TNF promoters that underlie functional changes in cell type- and stimulus-specific activation of the TNF gene. We have also identified ancestral TNF promoter nucleotide states in the primate lineage that correspond to human SNP alleles. These findings may reflect evolution of Asian and African apes under a distinct set of infectious disease pressures involving the innate immune response and TNF. PMID:17637837

Collagen Ialpha1 and vitamin D receptor gene polymorphisms in South African whites, blacks and Indians.

PubMed

Ojwang, P J; Pegoraro, R J; Rom, L; Lanning, P

2001-11-01

To determine whether polymorphic differences exist between black, white and Indian South Africans in genes associated with bone mineral density and osteoporosis. Genes selected were the vitamin D receptor (Apa I and Taq I polymorphisms) and collagen (Sp I transcription factor polymorphism) using standard molecular biology techniques. Department of Chemical Pathology, Nelson R Mandela School of Medicine, University of Natal, Durban, South Africa. Healthy male and female blood donors living in the Durban metropolitan region, South Africa. The group comprised black Africans (n=264), white Caucasians (n=247) and Asians of Indian origin (n=194). No significant differences in genotypes were seen between white and Indian subjects. Blacks had a significantly higher frequency of the TT Taq I genotype and a significantly lower frequency of the Ss Sp I genotype. No ss genotype was detected in blacks. The very low frequency of the collagen Sp I s allele and higher frequency of the VDR T allele in blacks may be associated with the lower incidence of osteoporosis in this ethnic group.

Environmental Adaptation Contributes to Gene Polymorphism across the Arabidopsis thaliana Genome

PubMed Central

Lee, Cheng-Ruei

2012-01-01

The level of within-species polymorphism differs greatly among genes in a genome. Many genomic studies have investigated the relationship between gene polymorphism and factors such as recombination rate or expression pattern. However, the polymorphism of a gene is affected not only by its physical properties or functional constraints but also by natural selection on organisms in their environments. Specifically, if functionally divergent alleles enable adaptation to different environments, locus-specific polymorphism may be maintained by spatially heterogeneous natural selection. To test this hypothesis and estimate the extent to which environmental selection shapes the pattern of genome-wide polymorphism, we define the "environmental relevance" of a gene as the proportion of genetic variation explained by environmental factors, after controlling for population structure. We found substantial effects of environmental relevance on patterns of polymorphism among genes. In addition, the correlation between environmental relevance and gene polymorphism is positive, consistent with the expectation that balancing selection among heterogeneous environments maintains genetic variation at ecologically important genes. Comparison of the gene ontology annotations shows that genes with high environmental relevance are enriched in unknown function categories. These results suggest an important role for environmental factors in shaping genome-wide patterns of polymorphism and indicate another direction of genomic study. PMID:22798389

Vitamin D receptor (VDR) polymorphisms and risk of ovarian cancer in Caucasian and African American women.

PubMed

Grant, Delores J; Hoyo, Cathrine; Akushevich, Lucy; Iversen, Edwin S; Whitaker, Regina; Marks, Jeffrey; Berchuck, Andrew; Schildkraut, Joellen M

2013-04-01

Polymorphisms in the vitamin D receptor (VDR) gene have been shown in some studies to be associated with the risk of epithelial ovarian cancer (EOC) in Caucasian women. There are no published reports among African Americans. Case-control data from the North Carolina Ovarian Cancer Study were analyzed using logistic regression to determine the association between seven VDR polymorphisms and EOC in both Caucasians (513 cases, 532 controls) and African Americans (74 cases, 79 controls). In a larger sample of African-Americans (125 cases, 155 controls), we assessed associations between six SNPs in proximity of rs7975232. African American women who carried at least one minor allele of rs7975232 were at higher risk for invasive EOC controlling for age and admixture with an odds ratio (OR) for association under the log-additive model of 2.08 (95% confidence interval (CI)=1.19, 3.63, p=0.010). No association was observed between any of the VDR variants and EOC among Caucasians. A larger sample of African Americans revealed a nearly two-fold increased risk of invasive EOC associated with rs7305032, a SNP in proximity to rs7975232 (R(2)=0.369) with a log-additive OR of 1.87 (95% CI=1.20, 2.93, p=0.006). This is the first report showing VDR variants associated with ovarian cancer risk in African American women. A larger study of African American women is needed to confirm these findings. These results imply that vitamin D exposure is a possible modifiable risk factor of ovarian cancer among African Americans. Copyright © 2012. Published by Elsevier Inc.

Novel associations of UDP-glucuronosyltransferase 2B gene variants with prostate cancer risk in a multiethnic study.

PubMed

Vidal, Adriana C; Tucker, Cocoa; Schildkraut, Joellen M; Richardson, Ricardo M; McPhail, Megan; Freedland, Stephen J; Hoyo, Cathrine; Grant, Delores J

2013-11-22

We have previously shown that a functional polymorphism of the UGT2B15 gene (rs1902023) was associated with increased risk of prostate cancer (PC). Novel functional polymorphisms of the UGT2B17 and UGT2B15 genes have been recently characterized by in vitro assays but have not been evaluated in epidemiologic studies. Fifteen functional SNPs of the UGT2B17 and UGT2B15 genes, including cis-acting UGT2B gene SNPs, were genotyped in African American and Caucasian men (233 PC cases and 342 controls). Regression models were used to analyze the association between SNPs and PC risk. After adjusting for race, age and BMI, we found that six UGT2B15 SNPs (rs4148269, rs3100, rs9994887, rs13112099, rs7686914 and rs7696472) were associated with an increased risk of PC in log-additive models (p < 0.05). A SNP cis-acting on UGT2B17 and UGT2B15 expression (rs17147338) was also associated with increased risk of prostate cancer (OR = 1.65, 95% CI = 1.00-2.70); while a stronger association among men with high Gleason sum was observed for SNPs rs4148269 and rs3100. Although small sample size limits inference, we report novel associations between UGT2B15 and UGT2B17 variants and PC risk. These associations with PC risk in men with high Gleason sum, more frequently found in African American men, support the relevance of genetic differences in the androgen metabolism pathway, which could explain, in part, the high incidence of PC among African American men. Larger studies are required.

Novel associations of UDP-glucuronosyltransferase 2B gene variants with prostate cancer risk in a multiethnic study

PubMed Central

2013-01-01

Background We have previously shown that a functional polymorphism of the UGT2B15 gene (rs1902023) was associated with increased risk of prostate cancer (PC). Novel functional polymorphisms of the UGT2B17 and UGT2B15 genes have been recently characterized by in vitro assays but have not been evaluated in epidemiologic studies. Methods Fifteen functional SNPs of the UGT2B17 and UGT2B15 genes, including cis-acting UGT2B gene SNPs, were genotyped in African American and Caucasian men (233 PC cases and 342 controls). Regression models were used to analyze the association between SNPs and PC risk. Results After adjusting for race, age and BMI, we found that six UGT2B15 SNPs (rs4148269, rs3100, rs9994887, rs13112099, rs7686914 and rs7696472) were associated with an increased risk of PC in log-additive models (p < 0.05). A SNP cis-acting on UGT2B17 and UGT2B15 expression (rs17147338) was also associated with increased risk of prostate cancer (OR = 1.65, 95% CI = 1.00-2.70); while a stronger association among men with high Gleason sum was observed for SNPs rs4148269 and rs3100. Conclusions Although small sample size limits inference, we report novel associations between UGT2B15 and UGT2B17 variants and PC risk. These associations with PC risk in men with high Gleason sum, more frequently found in African American men, support the relevance of genetic differences in the androgen metabolism pathway, which could explain, in part, the high incidence of PC among African American men. Larger studies are required. PMID:24267955

The dopamine-related polymorphisms BDNF, COMT, DRD2, DRD3, and DRD4 are not linked with changes in CSF dopamine levels and frequency of HIV infection.

PubMed

Horn, Anne; Scheller, C; du Plessis, S; Burger, R; Arendt, G; Joska, J; Sopper, S; Maschke, C M; Obermann, M; Husstedt, I W; Hain, J; Riederer, P; Koutsilieri, E

2017-04-01

We showed previously that higher levels in CSF dopamine in HIV patients are associated with the presence of the dopamine transporter (DAT) 10/10-repeat allele which was also detected more frequently in HIV-infected individuals compared to uninfected subjects. In the current study, we investigated further whether other genetic dopamine (DA)-related polymorphisms may be related with changes in CSF DA levels and frequency of HIV infection in HIV-infected subjects. Specifically, we studied genetic polymorphisms of brain-derived neurotrophic factor, catechol-O-methyltransferase, and dopamine receptors DRD2, DRD3, and DRD4 genetic polymorphisms in uninfected and HIV-infected people in two different ethnical groups, a German cohort (Caucasian, 72 individuals with HIV infection and 22 individuals without HIV infection) and a South African cohort (Xhosan, 54 individuals with HIV infection and 19 individuals without HIV infection). We correlated the polymorphisms with CSF DA levels, HIV dementia score, CD4 + T cell counts, and HIV viral load. None of the investigated DA-related polymorphisms was associated with altered CSF DA levels, CD4 + T cell count, viral load, and HIV dementia score. The respective allele frequencies were equally distributed between HIV-infected patients and controls. Our findings do not show any influence of the studied genetic polymorphisms on CSF DA levels and HIV infection. This is in contrast to what we found previously for the DAT 3'UTR VNTR and highlights the specific role of the DAT VNTR in HIV infection and disease.

Cytochrome and sulfotransferase gene variation in north African populations.

PubMed

Fernández-Santander, Ana; Novillo, Apolonia; Gaibar, María; Romero-Lorca, Alicia; Moral, Pedro; Sánchez-Cuenca, David; Amir, Nadir; Chaabani, Hassen; Harich, Nourdin; Esteban, Maria Esther

2016-08-01

To describe the diversity of four cytochrome and four sulfotransferase polymorphisms in six north African samples. Scarce data have been compiled for these samples despite the rich genetic background of north African populations. CYP3A4*1B, CYP3A4*17, CYP3A4*3, CYP3A5*3, SULT1A1*2, SULT1A2*2, SULT1A2*3 and SULT1E1*2 polymorphisms were explored in 556 individuals from Morocco, Algeria, Tunisia and Libya. Allele frequencies in our samples largely exceeded the variation ranges described for European populations, especially for CYP3A4*1B, SULT1A1*2 and SULT1A2*3. North African populations are heterogeneous, genetically diverse and show a considerable sub-Saharan African contribution for markers associated with increased risk of prostate cancer and with differential drug metabolism.

Comparative analysis of the prion protein gene sequences in African lion.

PubMed

Wu, Chang-De; Pang, Wan-Yong; Zhao, De-Ming

2006-10-01

The prion protein gene of African lion (Panthera Leo) was first cloned and polymorphisms screened. The results suggest that the prion protein gene of eight African lions is highly homogenous. The amino acid sequences of the prion protein (PrP) of all samples tested were identical. Four single nucleotide polymorphisms (C42T, C81A, C420T, T600C) in the prion protein gene (Prnp) of African lion were found, but no amino acid substitutions. Sequence analysis showed that the higher homology is observed to felis catus AF003087 (96.7%) and to sheep number M31313.1 (96.2%) Genbank accessed. With respect to all the mammalian prion protein sequences compared, the African lion prion protein sequence has three amino acid substitutions. The homology might in turn affect the potential intermolecular interactions critical for cross species transmission of prion disease.

Association Analysis in African Americans of European-Derived Type 2 Diabetes Single Nucleotide Polymorphisms From Whole-Genome Association Studies

PubMed Central

Lewis, Joshua P.; Palmer, Nicholette D.; Hicks, Pamela J.; Sale, Michele M.; Langefeld, Carl D.; Freedman, Barry I.; Divers, Jasmin; Bowden, Donald W.

2008-01-01

OBJECTIVE— Several whole-genome association studies have reported identification of type 2 diabetes susceptibility genes in various European-derived study populations. Little investigation of these loci has been reported in other ethnic groups, specifically African Americans. Striking differences exist between these populations, suggesting they may not share identical genetic risk factors. Our objective was to examine the influence of type 2 diabetes genes identified in whole-genome association studies in a large African American case-control population. RESEARCH DESIGN AND METHODS— Single nucleotide polymorphisms (SNPs) in 12 loci (e.g., TCF7L2, IDE/KIF11/HHEX, SLC30A8, CDKAL1, PKN2, IGF2BP2, FLJ39370, and EXT2/ALX4) associated with type 2 diabetes in European-derived populations were genotyped in 993 African American type 2 diabetic and 1,054 African American control subjects. Additionally, 68 ancestry-informative markers were genotyped to account for the impact of admixture on association results. RESULTS— Little evidence of association was observed between SNPs, with the exception of those in TCF7L2, and type 2 diabetes in African Americans. One TCF7L2 SNP (rs7903146) showed compelling evidence of association with type 2 diabetes (admixture-adjusted additive P [Pa] = 1.59 × 10−6). Only the intragenic SNP on 11p12 (rs9300039, dominant P [Pd] = 0.029) was also associated with type 2 diabetes after admixture adjustments. Interestingly, four of the SNPs are monomorphic in the Yoruba population of the HAPMAP project, with only the risk allele from the populations of European descent present. CONCLUSIONS— Results suggest that these variants do not significantly contribute to interindividual susceptibility to type 2 diabetes in African Americans. Consequently, genes contributing to type 2 diabetes in African Americans may, in part, be different from those in European-derived study populations. High frequency of risk alleles in several of these genes may, however, contribute to the increased prevalence of type 2 diabetes in African Americans. PMID:18443202

Association analysis in african americans of European-derived type 2 diabetes single nucleotide polymorphisms from whole-genome association studies.

PubMed

Lewis, Joshua P; Palmer, Nicholette D; Hicks, Pamela J; Sale, Michele M; Langefeld, Carl D; Freedman, Barry I; Divers, Jasmin; Bowden, Donald W

2008-08-01

Several whole-genome association studies have reported identification of type 2 diabetes susceptibility genes in various European-derived study populations. Little investigation of these loci has been reported in other ethnic groups, specifically African Americans. Striking differences exist between these populations, suggesting they may not share identical genetic risk factors. Our objective was to examine the influence of type 2 diabetes genes identified in whole-genome association studies in a large African American case-control population. Single nucleotide polymorphisms (SNPs) in 12 loci (e.g., TCF7L2, IDE/KIF11/HHEX, SLC30A8, CDKAL1, PKN2, IGF2BP2, FLJ39370, and EXT2/ALX4) associated with type 2 diabetes in European-derived populations were genotyped in 993 African American type 2 diabetic and 1,054 African American control subjects. Additionally, 68 ancestry-informative markers were genotyped to account for the impact of admixture on association results. Little evidence of association was observed between SNPs, with the exception of those in TCF7L2, and type 2 diabetes in African Americans. One TCF7L2 SNP (rs7903146) showed compelling evidence of association with type 2 diabetes (admixture-adjusted additive P [P(a)] = 1.59 x 10(-6)). Only the intragenic SNP on 11p12 (rs9300039, dominant P [P(d)] = 0.029) was also associated with type 2 diabetes after admixture adjustments. Interestingly, four of the SNPs are monomorphic in the Yoruba population of the HAPMAP project, with only the risk allele from the populations of European descent present. Results suggest that these variants do not significantly contribute to interindividual susceptibility to type 2 diabetes in African Americans. Consequently, genes contributing to type 2 diabetes in African Americans may, in part, be different from those in European-derived study populations. High frequency of risk alleles in several of these genes may, however, contribute to the increased prevalence of type 2 diabetes in African Americans.

Genome-Wide Association of the Laboratory-Based Nicotine Metabolite Ratio in Three Ancestries.

PubMed

Baurley, James W; Edlund, Christopher K; Pardamean, Carissa I; Conti, David V; Krasnow, Ruth; Javitz, Harold S; Hops, Hyman; Swan, Gary E; Benowitz, Neal L; Bergen, Andrew W

2016-09-01

Metabolic enzyme variation and other patient and environmental characteristics influence smoking behaviors, treatment success, and risk of related disease. Population-specific variation in metabolic genes contributes to challenges in developing and optimizing pharmacogenetic interventions. We applied a custom genome-wide genotyping array for addiction research (Smokescreen), to three laboratory-based studies of nicotine metabolism with oral or venous administration of labeled nicotine and cotinine, to model nicotine metabolism in multiple populations. The trans-3'-hydroxycotinine/cotinine ratio, the nicotine metabolite ratio (NMR), was the nicotine metabolism measure analyzed. Three hundred twelve individuals of self-identified European, African, and Asian American ancestry were genotyped and included in ancestry-specific genome-wide association scans (GWAS) and a meta-GWAS analysis of the NMR. We modeled natural-log transformed NMR with covariates: principal components of genetic ancestry, age, sex, body mass index, and smoking status. African and Asian American NMRs were statistically significantly (P values ≤ 5E-5) lower than European American NMRs. Meta-GWAS analysis identified 36 genome-wide significant variants over a 43 kilobase pair region at CYP2A6 with minimum P = 2.46E-18 at rs12459249, proximal to CYP2A6. Additional minima were located in intron 4 (rs56113850, P = 6.61E-18) and in the CYP2A6-CYP2A7 intergenic region (rs34226463, P = 1.45E-12). Most (34/36) genome-wide significant variants suggested reduced CYP2A6 activity; functional mechanisms were identified and tested in knowledge-bases. Conditional analysis resulted in intergenic variants of possible interest (P values < 5E-5). This meta-GWAS of the NMR identifies CYP2A6 variants, replicates the top-ranked single nucleotide polymorphism from a recent Finnish meta-GWAS of the NMR, identifies functional mechanisms, and provides pan-continental population biomarkers for nicotine metabolism. This multiple ancestry meta-GWAS of the laboratory study-based NMR provides novel evidence and replication for genome-wide association of CYP2A6 single nucleotide and insertion-deletion polymorphisms. We identify three regions of genome-wide significance: proximal, intronic, and distal to CYP2A6. We replicate the top-ranking single nucleotide polymorphism from a recent GWAS of the NMR in Finnish smokers, identify a functional mechanism for this intronic variant from in silico analyses of RNA-seq data that is consistent with CYP2A6 expression measured in postmortem lung and liver, and provide additional support for the intergenic region between CYP2A6 and CYP2A7. © The Author 2016. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco.

Genome-Wide Association of the Laboratory-Based Nicotine Metabolite Ratio in Three Ancestries

PubMed Central

Baurley, James W.; Edlund, Christopher K.; Pardamean, Carissa I.; Conti, David V.; Krasnow, Ruth; Javitz, Harold S.; Hops, Hyman; Swan, Gary E.; Benowitz, Neal L.

2016-01-01

Introduction: Metabolic enzyme variation and other patient and environmental characteristics influence smoking behaviors, treatment success, and risk of related disease. Population-specific variation in metabolic genes contributes to challenges in developing and optimizing pharmacogenetic interventions. We applied a custom genome-wide genotyping array for addiction research (Smokescreen), to three laboratory-based studies of nicotine metabolism with oral or venous administration of labeled nicotine and cotinine, to model nicotine metabolism in multiple populations. The trans-3′-hydroxycotinine/cotinine ratio, the nicotine metabolite ratio (NMR), was the nicotine metabolism measure analyzed. Methods: Three hundred twelve individuals of self-identified European, African, and Asian American ancestry were genotyped and included in ancestry-specific genome-wide association scans (GWAS) and a meta-GWAS analysis of the NMR. We modeled natural-log transformed NMR with covariates: principal components of genetic ancestry, age, sex, body mass index, and smoking status. Results: African and Asian American NMRs were statistically significantly (P values ≤ 5E-5) lower than European American NMRs. Meta-GWAS analysis identified 36 genome-wide significant variants over a 43 kilobase pair region at CYP2A6 with minimum P = 2.46E-18 at rs12459249, proximal to CYP2A6. Additional minima were located in intron 4 (rs56113850, P = 6.61E-18) and in the CYP2A6-CYP2A7 intergenic region (rs34226463, P = 1.45E-12). Most (34/36) genome-wide significant variants suggested reduced CYP2A6 activity; functional mechanisms were identified and tested in knowledge-bases. Conditional analysis resulted in intergenic variants of possible interest (P values < 5E-5). Conclusions: This meta-GWAS of the NMR identifies CYP2A6 variants, replicates the top-ranked single nucleotide polymorphism from a recent Finnish meta-GWAS of the NMR, identifies functional mechanisms, and provides pan-continental population biomarkers for nicotine metabolism. Implications: This multiple ancestry meta-GWAS of the laboratory study-based NMR provides novel evidence and replication for genome-wide association of CYP2A6 single nucleotide and insertion–deletion polymorphisms. We identify three regions of genome-wide significance: proximal, intronic, and distal to CYP2A6. We replicate the top-ranking single nucleotide polymorphism from a recent GWAS of the NMR in Finnish smokers, identify a functional mechanism for this intronic variant from in silico analyses of RNA-seq data that is consistent with CYP2A6 expression measured in postmortem lung and liver, and provide additional support for the intergenic region between CYP2A6 and CYP2A7. PMID:27113016

Chromosome 7p linkage and association study for diabetes related traits and type 2 diabetes in an African-American population enriched for nephropathy.

PubMed

Leak, Tennille S; Langefeld, Carl D; Keene, Keith L; Gallagher, Carla J; Lu, Lingyi; Mychaleckyj, Josyf C; Rich, Stephen S; Freedman, Barry I; Bowden, Donald W; Sale, Michèle M

2010-02-08

Previously we performed a linkage scan of 638 African American affected sibling pairs (ASP) with type 2 diabetes (T2D) enriched for end-stage renal disease (ESRD). Ordered subset linkage analysis (OSA) revealed a linkage peak on chromosome 7p in the subset of families with earlier age of T2D diagnosis. We fine mapped this region by genotyping 11 additional polymorphic markers in the same ASP and investigated a total of 68 single nucleotide polymorphisms (SNPs) in functional candidate genes (GCK1, IL6, IGFBP1 and IGFBP3) for association with age of T2D diagnosis, age of ESRD diagnosis, duration of T2D to onset of ESRD, body mass index (BMI) in African American cases and T2D-ESRD in an African American case-control cohort. OSA of fine mapping markers supported linkage at 28 cM on 7p (near D7S3051) in early-onset T2D families (max. LOD = 3.61, P = 0.002). SNPs in candidate genes and 70 ancestry-informative markers (AIMs) were evaluated in 577 African American T2D-ESRD cases and 596 African American controls. The most significant association was observed between ESRD age of diagnosis and SNP rs730497, located in intron 1 of the GCK1 gene (recessive T2D age-adjusted P = 0.0006). Nominal associations were observed with GCK1 SNPs and T2D age of diagnosis (BMI-adjusted P = 0.014 to 0.032). Also, one IGFBP1 and four IGFBP3 SNPs showed nominal genotypic association with T2D-ESRD (P = 0.002-0.049). After correcting for multiple tests, only rs730497 remanined significant. Variant rs730947 in the GCK1 gene appears to play a role in early ESRD onset in African Americans.

Identification of Polymorphisms in the 3′-Untranslated Region of the Human Pregnane X Receptor (PXR) Gene Associated with Variability in Cytochrome P450 3A (CYP3A) Metabolism

PubMed Central

Oleson, Lauren; von Moltke, Lisa L.; Greenblatt, David J.; Court, Michael H.

2013-01-01

Single nucleotide polymorphisms (SNPs) in the 3′untranslated region (3′UTR) of human pregnane X receptor (PXR) gene may contribute to interindividual variability in cytochrome P450 3A (CYP3A) activity. Genotype-phenotype associations involving PXR-3′UTR SNPs were investigated through in vitro (53 human livers from primarily white donors) and in vivo (26 white or African-American volunteers) studies using midazolam 1′-hydroxylation and midazolam apparent oral clearance (CL/F), respectively, as CYP3A-specific probes. PXR-3′UTR resequencing identified 12 SNPs, including 2 that were novel. Although none of the SNPs evaluated were associated with altered midazolam 1′-hydroxylation in the liver bank, both rs3732359 homozygotes and rs3732360 carriers showed 80% higher (P<0.05) CL/F compared with homozygous reference individuals. These differences in CL/F were even larger (100 and 120% higher, respectively; P<0.01) when only African-American subjects (n=14) were considered. Five major haplotypes were identified containing the PXR-3′UTR SNPs and previously identified intron SNPs. Although CL/F differences were not statistically significant within the entire study cohort, African-American carriers of Haplotype-1 (which includes both rs3732359 and rs3732360 variants) exhibited 70% higher median CL/F compared with African-American non-carriers (P=0.036). Our results identify rs3732359 and rs3732360 as PXR-3′UTR SNPs associated with higher CYP3A activity in vivo in African-Americans. PMID:20082578

FcγRIIIa SNPs and haplotypes affect human IgG binding and association with lupus nephritis in African Americans

PubMed Central

Dong, Chaoling; Ptacek, Travis S; Redden, David T; Zhang, Kui; Brown, Elizabeth E.; Edberg, Jeffrey C.; McGwin, Gerald; Alarcón, Graciela S.; Ramsey-Goldman, Rosalind; Reveille, John D.; Vilá, Luis M.; Petri, Michelle; Qin, Aijian; Wu, Jianming; Kimberly, Robert P.

2014-01-01

Objective To investigate whether the FcγRIIIa-66R/H/L polymorphism influences net effective receptor function and to assess if the FCGR3A combined genotypes formed by FcγRIIIa-66R/H/L and FcγRIIIa-176F/V as well as copy number variation (CNV) confer risk for development of SLE and lupus nephritis. Methods FcγRIIIa variants, expressed on A20 IIA1.6 cells, were used in flow cytometry-based human IgG binding assays. FCGR3A SNP and CNV genotypes were determined by Pyrosequencing methodology in a cohort of 1728 SLE patients and 2404 healthy controls. Results The FcγRIIIa-66L/H/R (rs10127939) polymorphism influences ligand binding capacity in the context of the FcγRIIIa-176V (rs396991) allele. The low binding FcγRIIIa-176F allele was associated with SLE nephritis (p = 0.0609) in African Americans but not in European Americans (p > 0.10). Nephritis among African American SLE subjects was associated with FcγRIIIa low binding haplotypes containing the 66R/H/L and 176F variants (p = 0.03) and with low binding genotype combinations (p = 0.002). No association was observed in European American SLE patients. The distribution of FCGR3A CNV was not significantly different between controls and SLE patients with or without nephritis. Conclusion FcγRIIIa-66R/H/L influences ligand binding. The low binding haplotypes formed by 66R/H/L and 176F confer enhanced risk for lupus nephritis in African Americans. FCGR3A CNVs are not associated with SLE or SLE nephritis in either African Americans or European Americans. PMID:24782186

Identifying Darwinian Selection Acting on Different Human APOL1 Variants among Diverse African Populations

PubMed Central

Ko, Wen-Ya; Rajan, Prianka; Gomez, Felicia; Scheinfeldt, Laura; An, Ping; Winkler, Cheryl A.; Froment, Alain; Nyambo, Thomas B.; Omar, Sabah A.; Wambebe, Charles; Ranciaro, Alessia; Hirbo, Jibril B.; Tishkoff, Sarah A.

2013-01-01

Disease susceptibility can arise as a consequence of adaptation to infectious disease. Recent findings have suggested that higher rates of chronic kidney disease (CKD) in individuals with recent African ancestry might be attributed to two risk alleles (G1 and G2) at the serum-resistance-associated (SRA)-interacting-domain-encoding region of APOL1. These two alleles appear to have arisen adaptively, possibly as a result of their protective effects against human African trypanosomiasis (HAT), or African sleeping sickness. In order to explore the distribution of potential functional variation at APOL1, we studied nucleotide variation in 187 individuals across ten geographically and genetically diverse African ethnic groups with exposure to two Trypanosoma brucei subspecies that cause HAT. We observed unusually high levels of nonsynonymous polymorphism in the regions encoding the functional domains that are required for lysing parasites. Whereas allele frequencies of G2 were similar across all populations (3%–8%), the G1 allele was only common in the Yoruba (39%). Additionally, we identified a haplotype (termed G3) that contains a nonsynonymous change at the membrane-addressing-domain-encoding region of APOL1 and is present in all populations except for the Yoruba. Analyses of long-range patterns of linkage disequilibrium indicate evidence of recent selection acting on the G3 haplotype in Fulani from Cameroon. Our results indicate that the G1 and G2 variants in APOL1 are geographically restricted and that there might be other functional variants that could play a role in HAT resistance and CKD risk in African populations. PMID:23768513

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alam, Asim; Mukhopadhyay, Nitai D.; Ning, Yi

Purpose: This study tested whether racial differences in genetic polymorphisms of 4 genes involved in wound repair and response to radiation can be used to predict the occurrence of normal tissue late effects of radiation therapy and indicate potential therapeutic targets. Methods and Materials: This prospective study examined genetic polymorphisms that modulate the expression of 4 genes involved in inflammation and fibrosis and response to radiation (HMOX1, NFE2L2, NOS3, and TGFβ1). DNA from blood samples of 179 patients (∼80% breast and head and neck) collected at the time of diagnosis by their radiation oncologist as exhibiting late normal tissue toxicitymore » was used for the analysis. Patient demographics were as follows: 56% white, 43% African American, 1% other. Allelic frequencies of the different polymorphisms of the participants were compared with those of the general American population stratified by race. Twenty-six additional patients treated with radiation, but without toxicity at 3 months or later after therapy, were also analyzed. Results: Increased frequency of a long GT repeat in the HMOX1 promoter was associated with late effects in both African American and white populations. The single nucleotide polymorphisms (SNP) rs1800469 in the TGFβ1 promoter and the rs6721961 SNP in the NFE2L2 promoter were also found to significantly associate with late effects in African Americans but not whites. A combined analysis of these polymorphisms revealed that >90% of African American patients with late effects had at least 1 of these minor alleles, and 58% had 2 or more. No statistical significance was found relating the studied NOS3 polymorphisms and normal tissue toxicity. Conclusions: These results support a strong association between wound repair and late toxicities of radiation. The presence of these genetic risk factors can vary significantly among different ethnic groups, as demonstrated for some of the SNPs. Future studies should account for the possibility of such ethnic heterogeneity in the late toxicities of radiation.« less

Recurrent Loss of APOBEC3H Activity during Primate Evolution.

PubMed

Garcia, Erin I; Emerman, Michael

2018-06-20

Genes in the APOBEC3 family encode cytidine deaminases that provide a barrier against viral infection and retrotransposition. Of all APOBEC3 genes in humans, APOBEC3H ( A3H ) is the most polymorphic: some haplotypes encode stable and active A3H proteins, while others are unstable and poorly antiviral. Such variation in human A3H affects interactions with the lentiviral antagonist Vif, which counteracts A3H via proteasomal degradation. In order to broaden our understanding of A3H-Vif interactions, as well as its evolution in Old World monkeys, we characterized A3H variation within four African green monkey (AGM) subspecies. We found that A3H is highly polymorphic in AGMs and has lost antiviral activity in multiple Old World monkeys. This loss of function was partially related to protein expression levels but was also influenced by amino acid mutations in the N-terminus. Moreover, we demonstrate that the evolution of A3H in the primate lineages leading to AGMs was not driven by Vif. Our work suggests that activity of A3H is evolutionarily dynamic and may have a negative effect on host fitness, resulting in its recurrent loss in primates. IMPORTANCE Adaptation of viruses to their hosts is critical for transmission of viruses between different species. Previous studies had identified changes in a protein from the APOBEC3 family that influenced species-specificity of simian immunodeficiency viruses (SIVs) in African green monkeys. We studied the evolution of a related protein in the same system, APOBEC3H, which has experienced a loss of function in humans. This evolutionary approach revealed that recurrent loss of APOBEC3H activity has taken place during primate evolution suggesting that APOBEC3H places a fitness cost on hosts. The variability of APOBEC3H activity between different primates highlights the differential selective pressures on the APOBEC3 gene family. Copyright © 2018 American Society for Microbiology.

Interactions of Cigarette Smoking with NAT2 Polymorphisms Impact Rheumatoid Arthritis Risk in African Americans

PubMed Central

Mikuls, Ted R.; LeVan, Tricia; Gould, Karen A.; Yu, Fang; Thiele, Geoffrey M.; Bynote, Kimberly K.; Conn, Doyt; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin; Brasington, Richard; Moreland, Larry W.; Reynolds, Richard; Gaffo, Angelo; Bridges, S. Louis

2011-01-01

Objective To examine whether polymorphisms in genes coding for drug metabolizing enzymes (DMEs) impact rheumatoid arthritis (RA) risk due to cigarette smoking in African Americans. Methods Smoking status was evaluated in African American RA cases and non-RA controls categorized as heavy (≥ 10 pack-years) vs. other. Individuals were genotyped for a homozygous deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) in addition to tagging single nucleotide polymorphisms (SNPs) in N-acetyltransferase (NAT)1, NAT2, and epoxide hydrolase (EPXH1). Associations of genotypes with RA were examined using logistic regression and gene-smoking interactions were assessed. Results There were no significant associations of any DME genotype with RA. After adjustment for multiple comparisons, there were significant additive interactions between heavy smoking and NAT2 SNPs rs9987109 (Padd = 0.000003) and rs1208 (Padd = 0.00001); attributable proportions (APs) due to interaction ranged from 0.61 to 0.67. None of the multiplicative gene-smoking interactions examined remained significant after adjustment for multiple testing in overall disease risk. There was no evidence of significant gene-smoking interactions in analyses of GSTM1-null, NAT1, or EPXH1. DME gene-smoking interactions were similar when cases were limited to anti-citrullinated protein antibody (ACPA) positive individuals. Conclusion Among African Americans, RA risk imposed by heavy smoking appears to be mediated in part by genetic variation in NAT2. While further studies are needed to elucidate mechanisms underpinning these interactions, these SNPs appear to identify African American smokers at a much higher risk for RA with relative risks that are at least two-fold higher compared to non-smokers lacking these risk alleles. PMID:21989592

The role of ancestry in TB susceptibility of an admixed South African population.

PubMed

Daya, Michelle; van der Merwe, Lize; van Helden, Paul D; Möller, Marlo; Hoal, Eileen G

2014-07-01

Genetic susceptibility to tuberculosis (TB) has been well established and this, taken together with variation in susceptibility observed between different geographic and ethnic populations, implies that susceptibility to TB may in part be affected by ethnicity. In a previous genome-wide TB case-control study (642 cases and 91 controls) of the admixed South African Coloured (SAC) population, we found a positive correlation between African San ancestry and TB susceptibility, and negative correlations with European and Asian ancestries. Since genome-wide data was available for only a small number of controls in the previous study, we endeavored to validate this finding by genotyping a panel of ancestry informative markers (AIMs) in additional individuals, yielding a data set of 918 cases and 507 controls. Ancestry proportions were estimated using the AIMs for each of the source populations of the SAC (African San, African non-San, European, South Asian and East Asian). Using logistic regression models to test for association between TB and ancestry, we confirmed the substantial effect of ancestry on TB susceptibility. We also investigated the effect of adjusting for ancestry in candidate gene TB association studies of the SAC. We report a polymorphism that is no longer significantly associated with TB after adjustment for ancestry, a polymorphism that is significantly associated with TB only after adjustment for ancestry, and a polymorphism where the association significance remains unchanged. By comparing the allele frequencies of these polymorphisms in the source populations of the SAC, we demonstrate that association results are likely to be affected by adjustment for ancestry if allele frequencies differ markedly in the source populations of the SAC. Copyright © 2014 Elsevier Ltd. All rights reserved.

Differences in candidate gene association between European ancestry and African American asthmatic children.

PubMed

Baye, Tesfaye M; Butsch Kovacic, Melinda; Biagini Myers, Jocelyn M; Martin, Lisa J; Lindsey, Mark; Patterson, Tia L; He, Hua; Ericksen, Mark B; Gupta, Jayanta; Tsoras, Anna M; Lindsley, Andrew; Rothenberg, Marc E; Wills-Karp, Marsha; Eissa, N Tony; Borish, Larry; Khurana Hershey, Gurjit K

2011-02-28

Candidate gene case-control studies have identified several single nucleotide polymorphisms (SNPs) that are associated with asthma susceptibility. Most of these studies have been restricted to evaluations of specific SNPs within a single gene and within populations from European ancestry. Recently, there is increasing interest in understanding racial differences in genetic risk associated with childhood asthma. Our aim was to compare association patterns of asthma candidate genes between children of European and African ancestry. Using a custom-designed Illumina SNP array, we genotyped 1,485 children within the Greater Cincinnati Pediatric Clinic Repository and Cincinnati Genomic Control Cohort for 259 SNPs in 28 genes and evaluated their associations with asthma. We identified 14 SNPs located in 6 genes that were significantly associated (p-values <0.05) with childhood asthma in African Americans. Among Caucasians, 13 SNPs in 5 genes were associated with childhood asthma. Two SNPs in IL4 were associated with asthma in both races (p-values <0.05). Gene-gene interaction studies identified race specific sets of genes that best discriminate between asthmatic children and non-allergic controls. We identified IL4 as having a role in asthma susceptibility in both African American and Caucasian children. However, while IL4 SNPs were associated with asthma in asthmatic children with European and African ancestry, the relative contributions of the most replicated asthma-associated SNPs varied by ancestry. These data provides valuable insights into the pathways that may predispose to asthma in individuals with European vs. African ancestry.

A GCH1 haplotype confers sex-specific susceptibility to pain crises and altered endothelial function in adults with sickle cell anemia

PubMed Central

Belfer, Inna; Youngblood, Victoria; Darbari, Deepika S.; Wang, Zhengyuan; Diaw, Lena; Freeman, Lita; Desai, Krupa; Dizon, Michael; Allen, Darlene; Cunnington, Colin; Channon, Keith M.; Milton, Jacqueline; Hartley, Stephen W.; Nolan, Vikki; Kato, Gregory J.; Steinberg, Martin H.; Goldman, David; Taylor, James G.

2014-01-01

GTP cyclohydrolase (GCH1) is rate limiting for tetrahydrobiopterin (BH4) synthesis, where BH4 is a cofactor for nitric oxide (NO) synthases and aromatic hydroxylases. GCH1 polymorphisms are implicated in the pathophysiology of pain, but have not been investigated in African populations. We examined GCH1 and pain in sickle cell anemia where GCH1 rs8007267 was a risk factor for pain crises in discovery (n = 228; odds ratio [OR] 2.26; P = 0.009) and replication (n = 513; OR 2.23; P = 0.004) cohorts. In vitro, cells from sickle cell anemia subjects homozygous for the risk allele produced higher BH4. In vivo physiological studies of traits likely to be modulated by GCH1 showed rs8007267 is associated with altered endothelial dependent blood flow in females with SCA (8.42% of variation; P = 0.002). The GCH1 pain association is attributable to an African haplotype with where its sickle cell anemia pain association is limited to females (OR 2.69; 95% CI 1.21–5.94; P = 0.01) and has the opposite directional association described in Europeans independent of global admixture. The presence of a GCH1 haplotype with high BH4 in populations of African ancestry could explain the association of rs8007267 with sickle cell anemia pain crises. The vascular effects of GCH1 and BH4 may also have broader implications for cardiovascular disease in populations of African ancestry. PMID:24136375

Myostatin and follistatin polymorphisms interact with muscle phenotypes and ethnicity.

PubMed

Kostek, Matthew A; Angelopoulos, Theodore J; Clarkson, Priscilla M; Gordon, Paul M; Moyna, Niall M; Visich, Paul S; Zoeller, Robert F; Price, Thomas B; Seip, Richard L; Thompson, Paul D; Devaney, Joseph M; Gordish-Dressman, Heather; Hoffman, Eric P; Pescatello, Linda S

2009-05-01

We examined associations among myostatin (MSTN) 2379 A > G and 163 G > A and follistatin (FST) -5003 A > T and -833 G > T single nucleotide polymorphisms (SNP) on the muscle size and the strength response to resistance training (RT). Subjects (n = 645, age = 24.1 +/- 0.2 yr, body mass index [BMI] = 24.2 +/- 0.2 kg x m(-2)) self-disclosed themselves as Caucasian (78.9%), African American (3.6%), Asian (8.4%), Hispanic (5.0%), or Other (4.2%). They were genotyped for MSTN 2379 A > G (n = 645), MSTN 163 G > A (n = 639), FST -5003 A > T (n = 580), and FST -833 G > T (n = 603). We assessed dynamic (one repetition maximum [1RM]) and isometric (maximum voluntary contraction [MVC]) muscle strength and size (cross-sectional area [CSA]) of the elbow flexors before and after 12 wk of unilateral upper-arm RT. Repeated-measures ANCOVA tested associations among genetic variants and muscle phenotypes with age and BMI as covariates. Baseline MVC was greater among African Americans who were carriers of the MSTN G(2379) allele (AG/GG, n = 15) than the A2379A homozygotes (n = 8; 64.2 +/- 6.8 vs 49.8 +/- 8.7 kg). African Americans who were carriers of the FST T(-5003) allele (n = 12) had greater baseline 1RM (11.9 +/- 0.7 vs 8.8 +/- 0.5 kg) and CSA (24.4 +/- 1.3 vs 19.1 +/- 1.2 cm(2)) than African Americans with the A-5003A genotype (n = 14; P < 0.05). No MSTN or FST genotype and muscle phenotype associations were found among the other ethnic groups (P >or= 0.05). MSTN 2379 A > G and FST -5003 A > T were associated with baseline muscle strength and size among African Americans only. These ethnic-specific associations are hypothesis generating and should be confirmed in a larger sample of African Americans.

The Arg72 variant of the p53 functional polymorphism (rs1042522) is associated with coronary artery disease in young South Africans of Indian ancestry.

PubMed

Khan, Sajidah; Phulukdaree, Alisa; Ramkaran, Prithiksha; Moodley, Devapregasan; Chuturgoon, Anil A

2016-11-30

Tumor protein p53 (p53), classically referred to as a tumor suppressor gene, is involved in cell cycle regulation and may be related to atherosclerosis by affecting smooth muscle cell proliferation, a feature of atherogenesis. A polymorphism at codon 72 (rs1042522) results in functional variability and hence plays a role in the pathophysiology of coronary artery disease (CAD). This polymorphism has been well established for its role in cancer and has only recently been investigated in CAD. Limited data is available on South Africans (SA) of Indian ancestry. We examined associations of this polymorphism and clinical markers in a cohort of young SA Indian CAD patients. A total of 284 subjects were recruited into this study which included 100 CAD patients (diagnosed on angiography, mean age 37.5, range 24-45years), 100 age- and sex-matched Indian controls and 84 age- and sex-matched Black controls. Polymorphic variants were assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Data for clinical markers were obtained from pathology reports. Genotype distribution differed significantly between CAD patients and Indian controls (Pro/Pro, Pro/Arg, Arg/Arg: 24%, 48%, 28% vs. 30%, 61%, 9% respectively, p=0.0025). There was a significant genotype distribution between Indian and Black controls (Pro/Pro, Pro/Arg, Arg/Arg: 30%, 61%, 9% vs. 45.2% 40.5%, 14.3% respectively, p=0.0212). A significantly higher frequency of the p53 Arg72 allele was found in CAD patients compared to controls (52% vs. 39.5% respectively, p=0.0159). The variant allele was slightly higher in Indian controls (39.5%) compared to Black controls (34.5%), but this did not reach statistical significance (p=0.3324). The levels of total cholesterol, LDL, HDL, triglycerides, fasting glucose, fasting insulin and %HbA1c were not significantly influenced by the p53 genotypic variants. Although the p53 codon 72 SNP is not associated with clinical markers of disease in CAD, the higher frequency of the variant allele in SA Indians may be a contributing factor for this population having an increased risk of developing premature CAD. Copyright © 2016. Published by Elsevier B.V.

Gene by Environment Investigation of Incident Lung Cancer Risk in African-Americans.

PubMed

David, Sean P; Wang, Ange; Kapphahn, Kristopher; Hedlin, Haley; Desai, Manisha; Henderson, Michael; Yang, Lingyao; Walsh, Kyle M; Schwartz, Ann G; Wiencke, John K; Spitz, Margaret R; Wenzlaff, Angela S; Wrensch, Margaret R; Eaton, Charles B; Furberg, Helena; Mark Brown, W; Goldstein, Benjamin A; Assimes, Themistocles; Tang, Hua; Kooperberg, Charles L; Quesenberry, Charles P; Tindle, Hilary; Patel, Manali I; Amos, Christopher I; Bergen, Andrew W; Swan, Gary E; Stefanick, Marcia L

2016-02-01

Genome-wide association studies have identified polymorphisms linked to both smoking exposure and risk of lung cancer. The degree to which lung cancer risk is driven by increased smoking, genetics, or gene-environment interactions is not well understood. We analyzed associations between 28 single nucleotide polymorphisms (SNPs) previously associated with smoking quantity and lung cancer in 7156 African-American females in the Women's Health Initiative (WHI), then analyzed main effects of top nominally significant SNPs and interactions between SNPs, cigarettes per day (CPD) and pack-years for lung cancer in an independent, multi-center case-control study of African-American females and males (1078 lung cancer cases and 822 controls). Nine nominally significant SNPs for CPD in WHI were associated with incident lung cancer (corrected p-values from 0.027 to 6.09 × 10(-5)). CPD was found to be a nominally significant effect modifier between SNP and lung cancer for six SNPs, including CHRNA5 rs2036527[A](betaSNP*CPD = - 0.017, p = 0.0061, corrected p = 0.054), which was associated with CPD in a previous genome-wide meta-analysis of African-Americans. These results suggest that chromosome 15q25.1 variants are robustly associated with CPD and lung cancer in African-Americans and that the allelic dose effect of these polymorphisms on lung cancer risk is most pronounced in lighter smokers.

Genetic analysis of Saccharomyces cerevisiae strains isolated from palm wine in eastern Nigeria. Comparison with other African strains.

PubMed

Ezeronye, O U; Legras, J-L

2009-05-01

To study the yeast diversity of Nigerian palm wines by comparison with other African strains. Twenty-three Saccharomyces cerevisiae strains were obtained from palm wine samples collected at four locations in eastern Nigeria, and characterized using different molecular techniques: internal transcribed spacer restriction fragment length polymorphism and sequence analysis, pulsed field gel electrophoresis, inter delta typing and microsatellite multilocus analysis. These techniques revealed that palm wine yeasts represent a group of closely related strains that includes other West African isolates (CBS400, NCYC110, DVPG6044). Population analysis revealed an excess of homozygote strains and an allelic richness similar to wine suggestive of local domestication. Several other African yeast strains were not connected to this group. Ghana sorghum beer strains and other African strains (DBVPG1853 and MUCL28071) displayed strikingly high relatedness with European bread, beer or wine strains, and the genome of strain MUCL30909 contained African and wine-type alleles, indicating its hybrid origin. Nigerian palm wine yeast represents a local specific yeast flora, whereas a European origin or hybrid was suspected for several other Africa isolates. This study presents the first genetic characterization of an autochthonous African palm wine yeast population and confirms the idea that human intervention has favoured yeast migration.

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

PubMed Central

Leppert, Tami; Anex, Deon S.; Hilmer, Jonathan K.; Matsunami, Nori; Baird, Lisa; Stevens, Jeffery; Parsawar, Krishna; Durbin-Johnson, Blythe P.; Rocke, David M.; Nelson, Chad; Fairbanks, Daniel J.; Wilson, Andrew S.; Rice, Robert H.; Woodward, Scott R.; Bothner, Brian; Hart, Bradley R.; Leppert, Mark

2016-01-01

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 single nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). This study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts. PMID:27603779

In Black South Africans from Rural and Urban Communities, the 4G/5G PAI-1 Polymorphism Influences PAI-1 Activity, but Not Plasma Clot Lysis Time

PubMed Central

de Lange, Zelda; Rijken, Dingeman C.; Hoekstra, Tiny; Conradie, Karin R.; Jerling, Johann C.; Pieters, Marlien

2013-01-01

Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT). We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009) but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central) obesity was the biggest contributor to PAI-1act variance (12.5%). Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT. PMID:24386152

In black South Africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time.

PubMed

de Lange, Zelda; Rijken, Dingeman C; Hoekstra, Tiny; Conradie, Karin R; Jerling, Johann C; Pieters, Marlien

2013-01-01

Data on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysis time (CLT). We also describe gene-environment interactions and the effect of urbanisation. Data from 2010 apparently healthy urban and rural black participants from the South African arm of the PURE study were cross-sectionally analysed. The 5G allele frequency of the 4G/5G polymorphism was 0.85. PAI-1act increased across genotypes in the urban subgroup (p = 0.009) but not significantly in the rural subgroup, while CLT did not differ across genotypes. Significant interaction terms were found between the 4G/5G polymorphism and BMI, waist circumference and triglycerides in determining PAI-1act, and between the 4G/5G polymorphism and fibrinogen and fibrinogen gamma prime in determining CLT. The C428T and G429A polymorphisms did not show direct relationships with PAI-1act or CLT but they did influence the association of other environmental factors with PAI-1act and CLT. Several of these interactions differed significantly between rural and urban subgroups, particularly in individuals harbouring the mutant alleles. In conclusion, although the 4G/5G polymorphism significantly affected PAI-1act, it contributed less than 1% to the PAI-1act variance. (Central) obesity was the biggest contributor to PAI-1act variance (12.5%). Urbanisation significantly influenced the effect of the 4G/5G polymorphism on PAI-1act as well as gene-environment interactions for the C428T and G429A genotypes in determining PAI-1act and CLT.

Identification of a null allele of cytochrome P450 3A7: CYP3A7 polymorphism in a Korean population.

PubMed

Lee, Sang Seop; Jung, Hyun-Ju; Park, Jung Soon; Cha, In-June; Cho, Doo-Yeoun; Shin, Jae-Gook

2010-01-01

Cytochrome P450 3A7 (CYP3A7) is expressed in the human fetal liver and plays a role in the metabolism of hormones, drugs, and toxic compounds. Genetic variants of CYP3A7 are associated with serum estrone level, bone density, and hepatic CYP3A activity in adults. We analyzed the genetic variations of CYP3A7 in a Korean population. From direct sequencing of all exons and flanking regions of the CYP3A7 gene in 48 Koreans, we found five genetic variants, including three novel variants. One variant, a thymidine insertion in exon 2 (4011insT), causes premature termination of CYP3A7 translation, which may result in a null phenotype. The novel variant was assigned to the CYP3A7*3 allele by the CYP allele nomenclature committee. For further screen of this novel variant in other ethnic populations, we used pyrosequencing to analyze an additional 185 Koreans, 100 African Americans, 100 Caucasians, and 159 Vietnamese for the presence of this variant. The variant was not found in any other individuals, except for one Korean subject. The frequencies of two known functional alleles, CYP3A7*2 and CYP3A7*1C, were 26 and 0%, respectively, in Koreans. The frequencies of the functional CYP3A7 polymorphisms in Koreans were significantly different from those in Caucasians and African Americans. This is the first report of a null-type allele of the CYP3A7 gene. It also provides population-level genetic data on CYP3A7 in Koreans to reveal the wide ethnic variation in CYP3A7 polymorphism.

Longitudinal analysis of haplotypes and polymorphisms of the APOA5 and APOC3 genes associated with variation in serum triglyceride levels: the Bogalusa Heart Study.

PubMed

Hallman, D Michael; Srinivasan, Sathanur R; Chen, Wei; Boerwinkle, Eric; Berenson, Gerald S

2006-12-01

Polymorphisms in the APOC3 and APOA5 genes, from the APOA1/APOC3/APOA4/APOA5 gene cluster on chromosome 11q23, have been associated with interindividual variation in plasma triglycerides. APOA5 polymorphisms implicated include 2 in the promoter region (-1131 T/C and -3 A/G) and 1 in exon 2 (+56 C/G). APOC3 polymorphisms implicated include 1 (SstI) in the 3' untranslated region and 1 (-2854 G/T) in the APOC3-APOA4 intergenic region. We analyzed the associations of haplotypes and multilocus genotypes of these polymorphisms on longitudinal serum triglyceride profiles in 360 African American and 823 white subjects from the Bogalusa Heart Study. Subjects were examined from 2 to 8 times (mean +/- SD, 5.4 +/- 1.3) between 1973 and 1996, at ages ranging from 4 to 38 years, with 1978 observations in African Americans and 4465 in whites. Serum triglycerides were significantly higher among whites across all ages. Allele frequencies differed significantly between African Americans and whites at all but the APOA5 +56 C/G locus. Linkage disequilibrium among the loci was higher in whites and haplotype diversity lower: 6 haplotypes had estimated frequencies of more than 1% in African Americans, 5 in whites. Individually, all polymorphisms except APOC3 -2854 G/T showed significant associations with triglyceride levels in the full sample. However, genotype models including all 5 loci showed significant triglyceride associations for only 3 (APOC3 SstI, APOA5 -1131 T/C, and APOA5 +56 C/G); significant interactions among them indicated their effects were not independent. Neither APOC3 -2854 G/T nor APOA5 -3 A/G had significant effects when the other 3 loci were in the models. The EM algorithm was used to estimate haplotype frequencies and assign haplotype probabilities to individuals, which is conditional on their genotypes; individuals' haplotype probability vectors were then used as predictors in multilevel mixed models of longitudinal triglyceride profiles. Of haplotypes comprising, in order, APOC3 SstI and -2854 G/T and APOA5 -1131 T/C, -3 A/G, and +56 C/G, 3 were significantly associated with higher triglycerides, even after adjusting for multiple tests: GGTAG (P = .002), GTTAG (P < .0001), and CGCGC (P = .0002). Each GGTAG haplotype carried would be expected to raise triglyceride levels (relative to those of GTTAC homozygotes) by approximately 19 mg/dL, each GTTAG haplotype by approximately 15 mg/dL, and each CGCGC haplotype by approximately 7 mg/dL. Haplotypes comprising the 3 loci implicated by genotype analyses (SstI, -1131 T/C, and +56 C/G) were also tested: haplotypes C_C_C and G_T_G significantly raised triglycerides, even after adjustment for multiple comparisons (P < .002 for both), with each copy of C_C_C expected to raise triglycerides by approximately 7 mg/dL and each copy of G_T_G by approximately 15 mg/dL. Overall, our findings support those of others in associating specific polymorphisms and haplotypes in the APOA1/C3/A4/A5 gene cluster with higher serum triglyceride levels. However, the degree to which polymorphisms in the APOC3 and APOA5 genes may be independently associated with triglyceride levels remains to be determined.

Extrapolating from local ecological processes to genus-wide patterns in colour polymorphism in South African Protea

PubMed Central

Carlson, Jane E.; Holsinger, Kent E.

2015-01-01

Polymorphic traits are central to many fundamental discoveries in evolution, yet why they are found in some species and not others remains poorly understood. We use the African genus Protea—within which more than 40% of species have co-occurring pink and white floral colour morphs—to ask whether convergent evolution and ecological similarity could explain the genus-wide pattern of polymorphism. First, we identified environmental correlates of pink morph frequency across 28 populations of four species. Second, we determined whether the same correlates could predict species-level polymorphism and monomorphism across 31 species. We found that pink morph frequency increased with elevation in Protea repens and three section Exsertae species, increased eastward in P. repens, and increased with seed predation intensity in section Exsertae. For cross-species comparisons, populations of monomorphic pink species occurred at higher elevations than populations of monomorphic white species, and 18 polymorphic species spanned broader elevational gradients than 13 monomorphic species. These results suggest that divergent selection along elevational clines has repeatedly favoured polymorphism, and that more uniform selection in altitudinally restricted species may promote colour monomorphism. Our findings are, to our knowledge, the first to link selection acting within species to the presence and absence of colour polymorphism at broader phylogenetic scales. PMID:25876847

Lysine-specific demethylase 1: an epigenetic regulator of salt-sensitive hypertension.

PubMed

Williams, Jonathan S; Chamarthi, Bindu; Goodarzi, Mark O; Pojoga, Luminita H; Sun, Bei; Garza, Amanda E; Raby, Benjamin A; Adler, Gail K; Hopkins, Paul N; Brown, Nancy J; Jeunemaitre, Xavier; Ferri, Claudio; Fang, Rui; Leonor, Thiago; Cui, Jinrui; Guo, Xiuqing; Taylor, Kent D; Ida Chen, Yii-Der; Xiang, Anny; Raffel, Leslie J; Buchanan, Thomas A; Rotter, Jerome I; Williams, Gordon H; Shi, Yujiang

2012-07-01

Hypertension (HTN) represents a complex heritable disease in which environmental factors may directly affect gene function via epigenetic mechanisms. The aim of this study was to test the hypothesis that dietary salt influences the activity of a histone-modifying enzyme, lysine-specific demethylase 1 (LSD-1), which in turn is associated with salt-sensitivity of blood pressure (BP). Animal and human studies were performed. Salt-sensitivity of LSD-1 expression was assessed in wild-type (WT) and LSD-1 heterozygote knockout (LSD-1(+/-)) mice. Clinical relevance was tested by multivariate associations between single-nuclear polymorphisms (SNPs) in the LSD-1 gene and salt-sensitivity of BP, with control of dietary sodium, in a primary African-American hypertensive cohort and two replication hypertensive cohorts (Caucasian and Mexican-American). LSD-1 expression was modified by dietary salt in WT mice with lower levels associated with liberal salt intake. LSD-1(+/-) mice expressed lower LSD-1 protein levels than WT mice in kidney tissue. Similar to LSD-1(+/-) mice, African-American minor allele carriers of two LSD-1 SNPs displayed greater change in systolic BP (SBP) in response to change from low to liberal salt diet (rs671357, P = 0.01; rs587168, P = 0.005). This association was replicated in the Hispanic (rs587168, P = 0.04) but not the Caucasian cohort. Exploratory analyses demonstrated decreased serum aldosterone concentrations in African-American minor allele carriers similar to findings in the LSD-1(+/-) mice, decreased α-EnaC expression in LSD-1(+/-) mice, and impaired renovascular responsiveness to salt loading in minor allele carriers. The results of this translational research study support a role for LSD-1 in the pathogenesis of salt-sensitive HTN.

Characterization of the genetic variation present in CYP3A4 in three South African populations.

PubMed

Drögemöller, Britt; Plummer, Marieth; Korkie, Lundi; Agenbag, Gloudi; Dunaiski, Anke; Niehaus, Dana; Koen, Liezl; Gebhardt, Stefan; Schneider, Nicol; Olckers, Antonel; Wright, Galen; Warnich, Louise

2013-01-01

The CYP3A4 enzyme is the most abundant human cytochrome P450 (CYP) and is regarded as the most important enzyme involved in drug metabolism. Inter-individual and inter-population variability in gene expression and enzyme activity are thought to be influenced, in part, by genetic variation. Although Southern African individuals have been shown to exhibit the highest levels of genetic diversity, they have been under-represented in pharmacogenetic research to date. Therefore, the aim of this study was to identify genetic variation within CYP3A4 in three South African population groups comprising of 29 Khoisan, 65 Xhosa and 65 Mixed Ancestry (MA) individuals. To identify known and novel CYP3A4 variants, 15 individuals were randomly selected from each of the population groups for bi-directional Sanger sequencing of ~600 bp of the 5'-upstream region and all thirteen exons including flanking intronic regions. Genetic variants detected were genotyped in the rest of the cohort. In total, 24 SNPs were detected, including CYP3A4(*)12, CYP3A4(*)15, and the reportedly functional CYP3A4(*)1B promoter polymorphism, as well as two novel non-synonymous variants. These putatively functional variants, p.R162W and p.Q200H, were present in two of the three populations and all three populations, respectively, and in silico analysis predicted that the former would damage the protein product. Furthermore, the three populations were shown to exhibit distinct genetic profiles. These results confirm that South African populations show unique patterns of variation in the genes encoding xenobiotic metabolizing enzymes. This research suggests that population-specific genetic profiles for CYP3A4 and other drug metabolizing genes would be essential to make full use of pharmacogenetics in Southern Africa. Further investigation is needed to determine if the identified genetic variants influence CYP3A4 metabolism phenotype in these populations.

Genetic moderation of child maltreatment effects on depression and internalizing symptoms by serotonin transporter linked polymorphic region (5-HTTLPR), brain-derived neurotrophic factor (BDNF), norepinephrine transporter (NET), and corticotropin releasing hormone receptor 1 (CRHR1) genes in African American children.

PubMed

Cicchetti, Dante; Rogosch, Fred A

2014-11-01

Genetic moderation of the effects of child maltreatment on depression and internalizing symptoms was investigated in a sample of low-income maltreated and nonmaltreated African American children (N = 1,096). Lifetime child maltreatment experiences were independently coded from Child Protective Services records and maternal report. Child depression and internalizing problems were assessed in the context of a summer research camp by self-report on the Children's Depression Inventory and adult counselor report on the Teacher Report Form. DNA was obtained from buccal cell or saliva samples and genotyped for polymorphisms of the following genes: serotonin transporter linked polymorphic region (5-HTTLPR), brain-derived neurotrophic factor (BDNF), norepinephrine transporter, and corticotropin releasing hormone receptor 1. Analyses of covariance with age and gender as covariates were conducted, with maltreatment status and respective polymorphism as main effects and their Gene × Environment (G × E) interactions. Maltreatment consistently was associated with higher Children's Depression Inventory and Teacher Report Form symptoms. The results for child self-report symptoms indicated a G × E interaction for BDNF and maltreatment. In addition, BDNF and triallelic 5-HTTLPR interacted with child maltreatment in a G × G × E interaction. Analyses for counselor report of child anxiety/depression symptoms on the Teacher Report Form indicated moderation of child maltreatment effects by triallelic 5-HTTLPR. These effects were elaborated based on variation in developmental timing of maltreatment experiences. Norepinephrine transporter was found to further moderate the G × E interaction of 5-HTTLPR and maltreatment status, revealing a G × G × E interaction. This G × G × E was extended by consideration of variation in maltreatment subtype experiences. Finally, G × G × E effects were observed for the co-action of BDNF and the corticotropin releasing hormone receptor 1 haplotype. The findings illustrate the variable influence of specific genotypes in G × E interactions based on variation in maltreatment experiences and the importance of a multigenic approach for understanding influences on depression and internalizing symptoms among African American children.

Identifying Darwinian selection acting on different human APOL1 variants among diverse African populations.

PubMed

Ko, Wen-Ya; Rajan, Prianka; Gomez, Felicia; Scheinfeldt, Laura; An, Ping; Winkler, Cheryl A; Froment, Alain; Nyambo, Thomas B; Omar, Sabah A; Wambebe, Charles; Ranciaro, Alessia; Hirbo, Jibril B; Tishkoff, Sarah A

2013-07-11

Disease susceptibility can arise as a consequence of adaptation to infectious disease. Recent findings have suggested that higher rates of chronic kidney disease (CKD) in individuals with recent African ancestry might be attributed to two risk alleles (G1 and G2) at the serum-resistance-associated (SRA)-interacting-domain-encoding region of APOL1. These two alleles appear to have arisen adaptively, possibly as a result of their protective effects against human African trypanosomiasis (HAT), or African sleeping sickness. In order to explore the distribution of potential functional variation at APOL1, we studied nucleotide variation in 187 individuals across ten geographically and genetically diverse African ethnic groups with exposure to two Trypanosoma brucei subspecies that cause HAT. We observed unusually high levels of nonsynonymous polymorphism in the regions encoding the functional domains that are required for lysing parasites. Whereas allele frequencies of G2 were similar across all populations (3%-8%), the G1 allele was only common in the Yoruba (39%). Additionally, we identified a haplotype (termed G3) that contains a nonsynonymous change at the membrane-addressing-domain-encoding region of APOL1 and is present in all populations except for the Yoruba. Analyses of long-range patterns of linkage disequilibrium indicate evidence of recent selection acting on the G3 haplotype in Fulani from Cameroon. Our results indicate that the G1 and G2 variants in APOL1 are geographically restricted and that there might be other functional variants that could play a role in HAT resistance and CKD risk in African populations. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Haptoglobin polymorphism among Saharian and West African groups. Haptoglobin phenotype determination by radioimmunoelectrophoresis on Hp O samples.

PubMed Central

Constans, J; Viau, M; Gouaillard, C; Clerc, A

1981-01-01

The haptoglobin (Hp) polymorphism is investigated in 11 African groups living in an area from the Algerian Sahara to Central Africa. More than 4,000 samples were examined. In the Saharian samples, the Hp1 gene frequency is higher than in any other African group. From north to south, a decrease in the Hp1 gene frequency is observed; in the Pygmy sample only, this frequency is lower than the frequency of the Hp2 gene. By means of a sensitive radioimmunoelectrophoresis, the presence of a residual Hp in Hp O sera in which the Hp polymorphism can also be determined can be revealed. Absence of Hp 1-1 and significant excess of Hp 2-2 individuals were observed. More Hp 2-1M phenotypes were detected in the Hp O population than in the non-Hp O population examined. In the Hp O samples, the influence of the phenotype distribution on the Hp gene frequencies is discussed. The heavy polymers of the Hp related to the presence of the alpha 2 chain (Hp2 gene product) are involved only in the biological mechanisms responsible for the presence of Hp O and Hp 2-1 M phenotypes among African groups. Images Fig. 1 PMID:7258189

Expression and sub-cellular localization of an epigenetic regulator, co-activator arginine methyltransferase 1 (CARM1), is associated with specific breast cancer subtypes and ethnicity

PubMed Central

2013-01-01

Background Co-Activator Arginine Methyltransferase 1(CARM1) is an Estrogen Receptor (ER) cofactor that remodels chromatin for gene regulation via methylation of Histone3. We investigated CARM1 levels and localization across breast cancer tumors in a cohort of patients of either European or African ancestry. Methods We analyzed CARM1 levels using tissue microarrays with over 800 histological samples from 549 female cancer patients from the US and Nigeria, Africa. We assessed associations between CARM1 expression localized to the nucleus and cytoplasm for 11 distinct variables, including; ER status, Progesterone Receptor status, molecular subtypes, ethnicity, HER2+ status, other clinical variables and survival. Results We found that levels of cytoplasmic CARM1 are distinct among tumor sub-types and increased levels are associated with ER-negative (ER-) status. Higher nuclear CARM1 levels are associated with HER2 receptor status. EGFR expression also correlates with localization of CARM1 into the cytoplasm. This suggests there are distinct functions of CARM1 among molecular tumor types. Our data reveals a basal-like subtype association with CARM1, possibly due to expression of Epidermal Growth Factor Receptor (EGFR). Lastly, increased cytoplasmic CARM1, relative to nuclear levels, appear to be associated with self-identified African ethnicity and this result is being further investigated using quantified genetic ancestry measures. Conclusions Although it is known to be an ER cofactor in breast cancer, CARM1 expression levels are independent of ER. CARM1 has distinct functions among molecular subtypes, as is indicative of its sub-cellular localization and it may function in subtype etiology. These sub-cellular localization patterns, indicate a novel role beyond its ER cofactor function in breast cancer. Differential localization among ethnic groups may be due to ancestry-specific polymorphisms which alter the gene product. PMID:23663560

Lack of specific alleles for the bovine chemokine (C-X-C) receptor type 4 (CXCR4) gene in West African cattle questions its role as a candidate for trypanotolerance.

PubMed

Álvarez, Isabel; Pérez-Pardal, Lucía; Traoré, Amadou; Fernández, Iván; Goyache, Félix

2016-08-01

A panel of 81 Asian, African and European cattle (Bos taurus and B. indicus) was analysed for the whole sequence of the CXCR4 gene (3844bp), a strong candidate for cattle trypanotolerance. Thirty-one polymorphic sites identified gave 31 different haplotypes. Neutrality tests rejected the hypothesis of either positive or purifying selection. Bayesian phylogenetic tree showed differentiation of haplotypes into two clades gathering genetic variability predating domestication. Related with clades definition, linkage disequilibrium analyses suggested the existence of one only linkage block on the CXCR4 gene. Two tag SNPs identified on exon 2 captured 50% of variability. Whatever the analysis carried out, no clear separation between cattle groups was identified. Most haplotypes identified in West African taurine cattle were also found in European cattle and in Asian and West African zebu. West African taurine samples did not carry unique variants on the CXCR4 gene sequence. The current analysis failed in identifying a causal mutation on the CXCR4 gene underlying a previously reported QTL for cattle trypanotolerance on BTA2. Copyright © 2016 Elsevier B.V. All rights reserved.

Demonstration of protein-based human identification using the hair shaft proteome [Protein-based human identification: A proof of concept using the hair shaft proteome

DOE PAGES

Parker, Glendon J.; Leppert, Tami; Anex, Deon S.; ...

2016-09-07

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 singlemore » nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). Furthermore, this study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.« less

Demonstration of protein-based human identification using the hair shaft proteome [Protein-based human identification: A proof of concept using the hair shaft proteome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Glendon J.; Leppert, Tami; Anex, Deon S.

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 singlemore » nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). Furthermore, this study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.« less

Genome-wide association studies in women of African ancestry identified 3q26.21 as a novel susceptibility locus for oestrogen receptor negative breast cancer.

PubMed

Huo, Dezheng; Feng, Ye; Haddad, Stephen; Zheng, Yonglan; Yao, Song; Han, Yoo-Jeong; Ogundiran, Temidayo O; Adebamowo, Clement; Ojengbede, Oladosu; Falusi, Adeyinka G; Zheng, Wei; Blot, William; Cai, Qiuyin; Signorello, Lisa; John, Esther M; Bernstein, Leslie; Hu, Jennifer J; Ziegler, Regina G; Nyante, Sarah; Bandera, Elisa V; Ingles, Sue A; Press, Michael F; Deming, Sandra L; Rodriguez-Gil, Jorge L; Nathanson, Katherine L; Domchek, Susan M; Rebbeck, Timothy R; Ruiz-Narváez, Edward A; Sucheston-Campbell, Lara E; Bensen, Jeannette T; Simon, Michael S; Hennis, Anselm; Nemesure, Barbara; Leske, M Cristina; Ambs, Stefan; Chen, Lin S; Qian, Frank; Gamazon, Eric R; Lunetta, Kathryn L; Cox, Nancy J; Chanock, Stephen J; Kolonel, Laurence N; Olshan, Andrew F; Ambrosone, Christine B; Olopade, Olufunmilayo I; Palmer, Julie R; Haiman, Christopher A

2016-11-01

Multiple breast cancer loci have been identified in previous genome-wide association studies, but they were mainly conducted in populations of European ancestry. Women of African ancestry are more likely to have young-onset and oestrogen receptor (ER) negative breast cancer for reasons that are unknown and understudied. To identify genetic risk factors for breast cancer in women of African descent, we conducted a meta-analysis of two genome-wide association studies of breast cancer; one study consists of 1,657 cases and 2,029 controls genotyped with Illumina’s HumanOmni2.5 BeadChip and the other study included 3,016 cases and 2,745 controls genotyped using Illumina Human1M-Duo BeadChip. The top 18,376 single nucleotide polymorphisms (SNP) from the meta-analysis were replicated in the third study that consists of 1,984 African Americans cases and 2,939 controls. We found that SNP rs13074711, 26.5 Kb upstream of TNFSF10 at 3q26.21, was significantly associated with risk of oestrogen receptor (ER)-negative breast cancer (odds ratio [OR]=1.29, 95% CI: 1.18-1.40; P = 1.8 × 10 − 8). Functional annotations suggest that the TNFSF10 gene may be involved in breast cancer aetiology, but further functional experiments are needed. In addition, we confirmed SNP rs10069690 was the best indicator for ER-negative breast cancer at 5p15.33 (OR = 1.30; P = 2.4 × 10 − 10) and identified rs12998806 as the best indicator for ER-positive breast cancer at 2q35 (OR = 1.34; P = 2.2 × 10 − 8) for women of African ancestry. These findings demonstrated additional susceptibility alleles for breast cancer can be revealed in diverse populations and have important public health implications in building race/ethnicity-specific risk prediction model for breast cancer.

Variants in toll-like receptors 2 and 9 influence susceptibility to pulmonary tuberculosis in Caucasians, African-Americans, and West Africans

PubMed Central

Velez, Digna Rosa; Wejse, Christian; Stryjewski, Martin E.; Abbate, Eduardo; Hulme, William F.; Myers, Jamie L.; Estevan, Rosa; Patillo, Sara G.; Olesen, Rikke; Tacconelli, Alessandra; Sirugo, Giorgio; Gilbert, John R.; Hamilton, Carol D.; Scott, William K.

2010-01-01

Tuberculosis (TB) is a global public health problem and a source of preventable deaths each year, with 8.8 million new cases of TB and 1.6 million deaths worldwide in 2005. Approximately, 10% of infected individuals develop pulmonary or extrapulmonary TB, suggesting that host defense factors influence development of active disease. Toll-like receptor’ (TLR) polymorphisms have been associated with regulation of TLR expression and development of active TB. In the present study, 71 polymorphisms in TLR1, TLR2, TLR4, TLR6, and TLR9 were examined from 474 (295 cases and 179 controls) African-Americans, 381 (237 cases and 144 controls) Caucasians, and from 667 (321 cases and 346 controls) Africans from Guinea-Bissau for association with pulmonary TB using generalized estimating equations and logistic regression. Statistically significant associations were observed across populations at TLR9 and TLR2. The strongest evidence for association came at an insertion (I)/deletion (D) polymorphism (−196 to −174) in TLR2 that associated with TB in both Caucasians (II vs. ID&DD, OR=0.41 [95% CI 0.24–0.68], p=0.0007) and Africans (II vs. ID&DD, OR=0.70 [95% CI 0.51–0.95], p=0.023). Our findings in three independent population samples indicate that variations in TLR2 and TLR9 might play important roles in determining susceptibility to TB. PMID:19771452

Serotonin-related FEV gene variant in the sudden infant death syndrome is a common polymorphism in the African-American population.

PubMed

Broadbelt, Kevin G; Barger, Melissa A; Paterson, David S; Holm, Ingrid A; Haas, Elisabeth A; Krous, Henry F; Kinney, Hannah C; Markianos, Kyriacos; Beggs, Alan H

2009-12-01

An important subset of the sudden infant death syndrome (SIDS) is associated with multiple serotonergic (5-HT) abnormalities in regions of the medulla oblongata. The mouse ortholog of the fifth Ewing variant gene (FEV) is critical for 5-HT neuronal development. A putatively rare intronic variant [IVS2-191_190insA, here referred to as c.128-(191_192)dupA] has been reported as a SIDS-associated mutation in an African-American population. We tested this association in an independent dataset: 137 autopsied cases (78 SIDS, 59 controls) and an additional 296 control DNA samples from Coriell Cell Repositories. In addition to the c.128-(191_192)dupA variant, we observed an associated single-base deletion [c.128-(301-306)delG] in a subset of the samples. Neither of the two FEV variants showed significant association with SIDS in either the African-American subgroup or the overall cohort. Although we found a significant association of c.128-(191_192)dupA with SIDS when San Diego Hispanic SIDS cases were compared with San Diego Hispanic controls plus Mexican controls (p = 0.04), this became nonsignificant after multiple testing correction. Among Coriell controls, 33 of 99 (33%) African-American and 0 of 197 (0%) of the remaining controls carry the polymorphism (c.128-(191_192)dupA). The polymorphism seems to be a common, likely nonpathogenic, variant in the African-American population.

Interactive influences of ethnicity, endothelin-1 gene, and everyday discrimination upon nocturnal ambulatory blood pressure.

PubMed

Gregoski, Mathew J; Buxbaum, Sarah G; Kapuku, Gaston; Dong, Yanbin; Zhu, Haidong; Davis, Mary; Gonto, Kelsey; Treiber, Frank A

2013-06-01

Everyday discrimination scale scores are associated with increased ambulatory blood pressure (BP) and reduced nocturnal dipping, and the endothelin-1 (ET-1)/Lys198Asn polymorphism is associated with increased resting BP and exaggerated BP reactivity among African Americans compared to European Americans. Combined influences of these factors on BP control are unknown. This study tested the hypothesis of a three-way interaction between ethnicity, ET-1 carrier status, and everyday discrimination upon ambulatory BP and nocturnal dipping. Baseline laboratory anthropometrics and the everyday discrimination scale were completed by 352 (175 African American) young adult normotensives, followed by 24-h ambulatory BP monitoring. For nocturnal dipping, multiple regression models controlling for age, sex, ethnicity, and body mass index revealed significant three-way ET-1 × everyday discrimination × ethnicity interactions. Specifically, among African American ET-1 T-allele carriers, increases in everyday discrimination led to reduced nocturnal dipping. African Americans that carry the ET-1/Lys198Asn T-allele and report higher everyday discrimination scores may be at particular risk for reduced nocturnal dipping.

Interactive Influences of Ethnicity, Endothelin-1 Gene, and Everyday Discrimination Upon Nocturnal Ambulatory Blood Pressure

PubMed Central

Gregoski, Mathew J.; Buxbaum, Sarah G.; Kapuku, Gaston; Dong, Yanbin; Zhu, Haidong; Davis, Mary; Gonto, Kelsey; Treiber, Frank A.

2013-01-01

Background Everyday discrimination scale scores are associated with increased ambulatory blood pressure (BP), and reduced nocturnal dipping, and the ET-1/Lys198Asn polymorphism is associated with increased resting BP and exaggerated BP reactivity among African Americans compared to European Americans. Combined influences of these factors on BP control are unknown. Purpose This study tested the hypothesis of a three-way interaction between ethnicity, ET-1 carrier status and everyday discrimination upon ambulatory BP and nocturnal dipping. Methods Baseline laboratory anthropometrics and the everyday discrimination scale were completed by 351 (175 African American) young adult normotensives; followed by 24-hour ambulatory BP monitoring. Results For nocturnal dipping, multiple regression models controlling for age, sex, race, and BMI revealed significant three-way ET-1 x everyday discrimination x ethnicity interactions. Specifically, among African American ET-1 T-allele carriers, increases in everyday discrimination led to reduced nocturnal dipping. Conclusions African Americans that carry the ET1/Lys198Asn T-allele and report higher everyday discrimination scores may be at particular risk for reduced nocturnal dipping. PMID:23436272

Population genetics of the potentially invasive African fruit fly species, Ceratitis rosa and Ceratitis fasciventris (Diptera: Tephritidae).

PubMed

Baliraine, F N; Bonizzoni, M; Guglielmino, C R; Osir, E O; Lux, S A; Mulaa, F J; Gomulski, L M; Zheng, L; Quilici, S; Gasperi, G; Malacrida, A R

2004-03-01

A set of 10 microsatellite markers was used to survey the levels of genetic variability and to analyse the genetic aspects of the population dynamics of two potentially invasive pest fruit fly species, Ceratitis rosa and C. fasciventris, in Africa. The loci were derived from the closely related species, C. capitata. The degree of microsatellite polymorphism in C. rosa and C. fasciventris was extensive and comparable to that of C. capitata. In C. rosa, the evolution of microsatellite polymorphism in its distribution area reflects the colonization history of this species. The mainland populations are more polymorphic than the island populations. Low levels of differentiation were found within the Africa mainland area, while greater levels of differentiation affect the islands. Ceratitis fasciventris is a central-east African species. The microsatellite data over the Uganda/Kenya spatial scale suggest a recent expansion and possibly continuing gene flow within this area. The microsatellite variability data from C. rosa and C. fasciventris, together with those of C. capitata, support the hypothesis of an east African origin of the Ceratitis spp.

Human Alu insertion polymorphisms in North African populations.

PubMed

Cherni, Loth; Frigi, Sabeh; Ennafaa, Hajer; Mtiraoui, Nabil; Mahjoub, Touhami; Benammar-Elgaaied, Amel

2011-10-01

Several features make Alu insertions a powerful tool used in population genetic studies: the polymorphic nature of many Alu insertions, the stability of an Alu insertion event and, furthermore, the ancestral state of an Alu insertion is known to be the absence of the Alu element at a particular locus and the presence of an Alu insertion at the site that forward mutational change. This study analyses seven Alu insertion polymorphisms in a sample of 297 individuals from the autochthonous population of Tunisia (Thala, Smar, Zarzis, and Bou Salem) and Libya with the aim of studying their genetic structure with respect to the populations of North Africa, Western, Eastern and Central Europe. The comparative analyses carried out using the MDS and AMOVA methods reveal the existence of spatial heterogeneity, and identify four population groups. Study populations (Libya, Smar, Zarzis, and Bou Salem) are closest to North African populations whereas Thala is isolated and is closest to Western European populations. In conclusion, Results of the present study support the important role that migratory movements have played in the North African gene pool, at least since the Neolithic period.

Associations between the SS variant of 5-HTTLPR and PTSD among adults with histories of childhood emotional abuse: results from two African American independent samples.

PubMed

Walsh, Kate; Uddin, Monica; Soliven, Richelo; Wildman, Derek E; Bradley, Bekh

2014-06-01

Prior studies have found that the 5-HTTLPR polymorphism in the promoter region of the serotonin transporter gene (SLC6A4) interacts with stressful life events to increase general risk for PTSD, but this association has not extended to African American samples. Further, little is known about the effects of this interaction on specific PTSD symptom clusters, despite indications that clusters may have different biological substrates. The current study examined the interaction between exposure to childhood emotional abuse and 5-HTTLPR genotype on risk for PTSD symptom severity and severity of specific PTSD symptom clusters in two African American samples. Participants were 136 African American household residents from Detroit, MI and 546 African American patients recruited from waiting rooms in primary care clinics in Atlanta, GA. Participants reported emotional abuse exposure and PTSD symptom severity, and provided DNA for triallelic 5-HTTLPR genotyping. Analysis of covariance (ANCOVA) was used to examine main effects and interactions. In both African American samples, 5-HTTLPR genotype modified the effect of emotional abuse on PTSD symptom severity. Participants with the low-expression SS genotype who were exposed to emotional abuse had significantly lower reexperiencing and arousal symptom severity scores. The DNHS genetic sample size was small, and abuse data were assessed retrospectively. The SS variant of 5-HTTLPR appears to buffer against developing the reexperiencing and arousal symptoms of PTSD in two independent African American samples exposed to childhood emotional abuse. Findings also highlight the importance of considering emotional abuse experiences in patients with suspected PTSD. Copyright © 2014 Elsevier B.V. All rights reserved.

Genotype-phenotype associations for common CYP3A4 and CYP3A5 variants in the basal and induced metabolism of midazolam in European- and African-American men and women.

PubMed

Floyd, Michael D; Gervasini, Guillermo; Masica, Andrew L; Mayo, Gail; George, Alfred L; Bhat, Kolari; Kim, Richard B; Wilkinson, Grant R

2003-10-01

CYP3A activity in adults varies between individuals and it has been suggested that this has a genetic basis, possibly related to variant alleles in CYP3A4 and CYP3A5 genes. Accordingly, genotype-phenotype associations were investigated under constitutive and induced conditions. Midazolam's systemic and oral clearances, and the erythromycin breath test (ERBT) were determined in 57 healthy subjects: 23 (11 men, 12 women) European- and 34 (14 men, 20 women) African-Americans. Studies were undertaken in the basal state and after 14-15 days pretreatment with rifampin. DNA was characterized for the common polymorphisms CYP3A4*1B, CYP3A5*3, CYP3A5*6 and CYP3A5*7 by direct sequencing, and for exon 21 and exon 26 variants of MDR1 by allele-specific, real-time polymerase chain reaction. In 95% of subjects, the basal systemic clearance of midazolam was unimodally distributed and variability was less than four-fold whereas, in 98% of the study population, oral clearance varied five-fold. No population or sex-related differences were apparent. Similar findings were observed with the ERBT. Rifampin pretreatment markedly increased the systemic (two-fold) and oral clearance (16-fold) of midazolam, and the ERBT (two-fold) but the variabilities were unchanged. No associations were noted between these phenotypic measures and any of the studied genotypes, except for oral clearance and its fold-increase after rifampin. These were related to the presence of CYP3A4*1B and the inversely linked CYP3A5*3 polymorphism, with the extent of induction being approximately 50% greater in CYP3A5*3 homozygotes compared to wild-type subjects. In most healthy subjects, variability in intestinal and hepatic CYP3A activity, using midazolam as an in-vivo probe, is modest and common polymorphisms in CYP3A4 and CYP3A5 do not appear to have important functional significance.

East African cheetahs: evidence for two population bottlenecks?

PubMed Central

O'Brien, S J; Wildt, D E; Bush, M; Caro, T M; FitzGibbon, C; Aggundey, I; Leakey, R E

1987-01-01

A combined population genetic and reproductive analysis was undertaken to compare free-ranging cheetahs from east Africa (Acinonyx jubatus raineyi) with the genetically impoverished and reproductively impaired south African subspecies (Acinonyx jubatus jubatus). Like that of their south African counterparts, the quality of semen specimens from east African cheetahs was poor, with a low concentration of spermatozoa (25.3 X 10(6) per ejaculate) and a high incidence of morphological abnormalities (79%). From an electrophoretic survey of the products of 49 genetic loci in A. jubatus raineyi, two allozyme polymorphisms were detected; one of these, for a nonspecific esterase, shows an allele that is rare (less than 1% incidence) in south African specimens. Estimates of polymorphism (2-4%) and average heterozygosity (0.0004-0.014) affirm the cheetah as the least genetically variable felid species. The genetic distance between south and east African cheetahs was low (0.004), suggesting that the development of genetic uniformity preceded the recent geographic isolation of the subspecies. We propose that at least two population bottlenecks followed by inbreeding produced the modern cheetah species. The first and most extreme was ancient, possibly late Pleistocene (circa 10,000 years ago); the second was more recent (within the last century) and led to the south African populations. PMID:3467370

Neanderthal and Denisova tooth protein variants in present-day humans

PubMed Central

Zanolli, Clément; Hourset, Mathilde; Esclassan, Rémi

2017-01-01

Environment parameters, diet and genetic factors interact to shape tooth morphostructure. In the human lineage, archaic and modern hominins show differences in dental traits, including enamel thickness, but variability also exists among living populations. Several polymorphisms, in particular in the non-collagenous extracellular matrix proteins of the tooth hard tissues, like enamelin, are involved in dental structure variation and defects and may be associated with dental disorders or susceptibility to caries. To gain insights into the relationships between tooth protein polymorphisms and dental structural morphology and defects, we searched for non-synonymous polymorphisms in tooth proteins from Neanderthal and Denisova hominins. The objective was to identify archaic-specific missense variants that may explain the dental morphostructural variability between extinct and modern humans, and to explore their putative impact on present-day dental phenotypes. Thirteen non-collagenous extracellular matrix proteins specific to hard dental tissues have been selected, searched in the publicly available sequence databases of Neanderthal and Denisova individuals and compared with modern human genome data. A total of 16 non-synonymous polymorphisms were identified in 6 proteins (ameloblastin, amelotin, cementum protein 1, dentin matrix acidic phosphoprotein 1, enamelin and matrix Gla protein). Most of them are encoded by dentin and enamel genes located on chromosome 4, previously reported to show signs of archaic introgression within Africa. Among the variants shared with modern humans, two are ancestral (common with apes) and one is the derived enamelin major variant, T648I (rs7671281), associated with a thinner enamel and specific to the Homo lineage. All the others are specific to Neanderthals and Denisova, and are found at a very low frequency in modern Africans or East and South Asians, suggesting that they may be related to particular dental traits or disease susceptibility in these populations. This modern regional distribution of archaic dental polymorphisms may reflect persistence of archaic variants in some populations and may contribute in part to the geographic dental variations described in modern humans. PMID:28902892

Sex dependent influence of a functional polymorphism in steroid 5-α-reductase type 2 (SRD5A2) on post-traumatic stress symptoms.

PubMed

Gillespie, Charles F; Almli, Lynn M; Smith, Alicia K; Bradley, Bekh; Kerley, Kimberly; Crain, Daniel F; Mercer, Kristina B; Weiss, Tamara; Phifer, Justine; Tang, Yilang; Cubells, Joseph F; Binder, Elisabeth B; Conneely, Karen N; Ressler, Kerry J

2013-04-01

A non-synonymous, single nucleotide polymorphism (SNP) in the gene coding for steroid 5-α-reductase type 2 (SRD5A2) is associated with reduced conversion of testosterone to dihydrotestosterone (DHT). Because SRD5A2 participates in the regulation of testosterone and cortisol metabolism, hormones shown to be dysregulated in patients with PTSD, we examined whether the V89L variant (rs523349) influences risk for post-traumatic stress disorder (PTSD). Study participants (N = 1,443) were traumatized African-American patients of low socioeconomic status with high rates of lifetime trauma exposure recruited from the primary care clinics of a large, urban hospital. PTSD symptoms were measured with the post-traumatic stress symptom scale (PSS). Subjects were genotyped for the V89L variant (rs523349) of SRD5A2. We initially found a significant sex-dependent effect of genotype in male but not female subjects on symptoms. Associations with PTSD symptoms were confirmed using a separate internal replication sample with identical methods of data analysis, followed by pooled analysis of the combined samples (N = 1,443, sex × genotype interaction P < 0.002; males: n = 536, P < 0.001). These data support the hypothesis that functional variation within SRD5A2 influences, in a sex-specific way, the severity of post-traumatic stress symptoms and risk for diagnosis of PTSD. Copyright © 2013 Wiley Periodicals, Inc.

Genetic variants in one-carbon metabolism genes and breast cancer risk in European American (EA) and African American (AA) women

PubMed Central

Gong, Zhihong; Yao, Song; Zirpoli, Gary; Cheng, Ting-Yuan David; Roberts, Michelle; Khoury, Thaer; Ciupak, Gregory; Davis, Warren; Pawlish, Karen; Jandorf, Lina; Bovbjerg, Dana H.; Bandera, Elisa V.; Ambrosone, Christine B.

2015-01-01

Folate-mediated one-carbon metabolism plays critical roles in DNA synthesis, repair, and DNA methylation. The impact of single nucleotide polymorphisms (SNPs) in folate-metabolizing enzymes has been investigated in risk of breast cancer among European or Asian populations, but not among women of African ancestry. We conducted a comprehensive analysis of SNPs in eleven genes involved in one-carbon metabolism and risk of breast cancer in 1,275 European-American (EA) and 1,299 African-American (AA) women who participated in the Women’s Circle of Health Study. Allele frequencies varied significantly between EA and AA populations. A number of these SNPs, specifically in genes including MTR, MTRR, SHMT1, TYMS, and SLC19A1, were associated with overall breast cancer risk, as well as risk by estrogen receptor (ER) status, in either EA or AA women. Associations appeared to be modified by dietary folate intake. Although single-SNP associations were not statistically significant after correcting for multiple comparisons, polygenetic score analyses revealed significant associations with breast cancer risk. Per unit increase of the risk score was associated with a modest 19% to 50% increase in risk of breast cancer overall, ER positive or ER negative cancer (all P<0.0005) in EAs or AAs. In summary, our data suggest that one-carbon metabolizing gene polymorphisms could play a role in breast cancer and that may differ between EA and AA women. PMID:25598430

Extrapolating from local ecological processes to genus-wide patterns in colour polymorphism in South African Protea.

PubMed

Carlson, Jane E; Holsinger, Kent E

2015-05-07

Polymorphic traits are central to many fundamental discoveries in evolution, yet why they are found in some species and not others remains poorly understood. We use the African genus Protea-within which more than 40% of species have co-occurring pink and white floral colour morphs-to ask whether convergent evolution and ecological similarity could explain the genus-wide pattern of polymorphism. First, we identified environmental correlates of pink morph frequency across 28 populations of four species. Second, we determined whether the same correlates could predict species-level polymorphism and monomorphism across 31 species. We found that pink morph frequency increased with elevation in Protea repens and three section Exsertae species, increased eastward in P. repens, and increased with seed predation intensity in section Exsertae. For cross-species comparisons, populations of monomorphic pink species occurred at higher elevations than populations of monomorphic white species, and 18 polymorphic species spanned broader elevational gradients than 13 monomorphic species. These results suggest that divergent selection along elevational clines has repeatedly favoured polymorphism, and that more uniform selection in altitudinally restricted species may promote colour monomorphism. Our findings are, to our knowledge, the first to link selection acting within species to the presence and absence of colour polymorphism at broader phylogenetic scales. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Challenges Experienced by District-Based Support Teams in the Execution of Their Functions in a Specific South African Province

ERIC Educational Resources Information Center

Makhalemele, Thabo; Nel, Mirna

2016-01-01

This article reports on the findings of an embedded mixed-method South African study that investigated the challenges experienced by District-Based Support Team (DBST) members in the sub-directorate of Inclusive Education of a South African province in the execution of their functions. A Likert-scale questionnaire and individual semi-structured…

Balancing Selection on a Regulatory Region Exhibiting Ancient Variation That Predates Human–Neandertal Divergence

PubMed Central

Iskow, Rebecca C.; Austermann, Christian; Scharer, Christopher D.; Raj, Towfique; Boss, Jeremy M.; Sunyaev, Shamil; Price, Alkes; Stranger, Barbara; Simon, Viviana; Lee, Charles

2013-01-01

Ancient population structure shaping contemporary genetic variation has been recently appreciated and has important implications regarding our understanding of the structure of modern human genomes. We identified a ∼36-kb DNA segment in the human genome that displays an ancient substructure. The variation at this locus exists primarily as two highly divergent haplogroups. One of these haplogroups (the NE1 haplogroup) aligns with the Neandertal haplotype and contains a 4.6-kb deletion polymorphism in perfect linkage disequilibrium with 12 single nucleotide polymorphisms (SNPs) across diverse populations. The other haplogroup, which does not contain the 4.6-kb deletion, aligns with the chimpanzee haplotype and is likely ancestral. Africans have higher overall pairwise differences with the Neandertal haplotype than Eurasians do for this NE1 locus (p<10−15). Moreover, the nucleotide diversity at this locus is higher in Eurasians than in Africans. These results mimic signatures of recent Neandertal admixture contributing to this locus. However, an in-depth assessment of the variation in this region across multiple populations reveals that African NE1 haplotypes, albeit rare, harbor more sequence variation than NE1 haplotypes found in Europeans, indicating an ancient African origin of this haplogroup and refuting recent Neandertal admixture. Population genetic analyses of the SNPs within each of these haplogroups, along with genome-wide comparisons revealed significant FST (p = 0.00003) and positive Tajima's D (p = 0.00285) statistics, pointing to non-neutral evolution of this locus. The NE1 locus harbors no protein-coding genes, but contains transcribed sequences as well as sequences with putative regulatory function based on bioinformatic predictions and in vitro experiments. We postulate that the variation observed at this locus predates Human–Neandertal divergence and is evolving under balancing selection, especially among European populations. PMID:23593015

Single nucleotide polymorphisms related to cystic fibrosis in chronic rhinositus-a pilot study.

PubMed

Hull, Benjamin P; Jiramongkolchai, Pawina; Turner, Justin H; Olson, Lana; Chandra, Rakesh K

2017-05-01

The clinical association between cystic fibrosis (CF) and chronic rhinosinusitis (CRS) is well known. Studies have identified several non-CF transmembrane conductance regulator single nucleotide polymorphisms (SNPs) associated with disease severity in CF patients. We hypothesized that prevalence of these SNPs would be different between CRS patients and age/gender-matched non-CRS controls. This is a targeted SNP study of 1231 CRS patients identified through a large university hospital database who were compared with 8796 age- and gender-matched controls without a history of rhinitis, sinusitis, allergies, or asthma. Prevalence of 5 relevant SNPs was compared between groups, with p < 0.05 considered significant. Stratification by race and gender was performed among groups when statistically appropriate. CRS patients exhibited a statistically significant (p = 0.036) lower prevalence of rs12883884 (associated with an ion transporter) compared with controls. This association was lost when patients were stratified by race. CRS patients manifested a greater prevalence of rs1403543 (chromosome 23) in both Caucasian and African American subgroups (p = 0.036 and p = 0.026, respectively). Statistical significance disappeared among Caucasians when stratified by gender, but persisted among African American women (p = 0.047). rs12188164 and rs12793173 were both more prevalent in African Americans with CRS than controls (p = 0.042 and p = 0.020, respectively). A trend was also observed for decreased prevalence of rs12883884 in CRS patients compared with controls in the African American subgroup (p = 0.086). The identified SNPs were differentially prevalent in CRS compared with control groups, with some variability as a function of race and gender. Further research is required to confirm these findings and elucidate clinical significance. © 2017 ARS-AAOA, LLC.

Population-specific variation in haplotype composition and heterozygosity at the POLB locus.

PubMed

Yamtich, Jennifer; Speed, William C; Straka, Eva; Kidd, Judith R; Sweasy, Joann B; Kidd, Kenneth K

2009-05-01

DNA polymerase beta plays a central role in base excision repair (BER), which removes large numbers of endogenous DNA lesions from each cell on a daily basis. Little is currently known about germline polymorphisms within the POLB locus, making it difficult to study the association of variants at this locus with human diseases such as cancer. Yet, approximately thirty percent of human tumor types show variants of DNA polymerase beta. We have assessed the global frequency distributions of coding and common non-coding SNPs in and flanking the POLB gene for a total of 14 sites typed in approximately 2400 individuals from anthropologically defined human populations worldwide. We have found a marked difference between haplotype frequencies in African populations and in non-African populations.

Frequency of APOE, MTHFR and ACE polymorphisms in the Zambian population

PubMed Central

2014-01-01

Background Polymorphisms within the apolipoprotein-E (APOE), Methylenetetrahydrofolate reductase (MTHFR) and Angiotensin I-converting enzyme (ACE) genes has been associated with cardiovascular and cerebrovascular disorders, Alzheimer’s disease and other complex diseases in various populations. The aim of the study was to analyze the allelic and genotypic frequencies of APOE, MTHFR C677T and ACE I/D gene polymorphisms in the Zambian population. Results The allele frequencies of APOE polymorphism in the Zambian populations were 13.8%, 59.5% and 26.7% for the ε2, ε3 and ε4 alleles respectively. MTHFR C677T and ACE I/D allele frequencies were 8.6% and 13.8% for the T and D minor alleles respectively. The ε2ε2 genotype and TT genotype were absent in the Zambian population. The genetic distances between Zambian and other African and non-African major populations revealed an independent variability of these polymorphisms. Conclusion We found that the APOE ε3 allele and the I allele of the ACE were significantly high in our study population while there were low frequencies observed for the MTHFR 677 T and ACE D alleles. Our analysis of the APOE, MTHFR and ACE polymorphisms may provide valuable insight into the understanding of the disease risk in the Zambian population. PMID:24679048

Single nucleotide polymorphisms in bone turnover-related genes in Koreans: ethnic differences in linkage disequilibrium and haplotype

PubMed Central

Kim, Kyung-Seon; Kim, Ghi-Su; Hwang, Joo-Yeon; Lee, Hye-Ja; Park, Mi-Hyun; Kim, Kwang-joong; Jung, Jongsun; Cha, Hyo-Soung; Shin, Hyoung Doo; Kang, Jong-Ho; Park, Eui Kyun; Kim, Tae-Ho; Hong, Jung-Min; Koh, Jung-Min; Oh, Bermseok; Kimm, Kuchan; Kim, Shin-Yoon; Lee, Jong-Young

2007-01-01

Background Osteoporosis is defined as the loss of bone mineral density that leads to bone fragility with aging. Population-based case-control studies have identified polymorphisms in many candidate genes that have been associated with bone mass maintenance or osteoporotic fracture. To investigate single nucleotide polymorphisms (SNPs) that are associated with osteoporosis, we examined the genetic variation among Koreans by analyzing 81 genes according to their function in bone formation and resorption during bone remodeling. Methods We resequenced all the exons, splice junctions and promoter regions of candidate osteoporosis genes using 24 unrelated Korean individuals. Using the common SNPs from our study and the HapMap database, a statistical analysis of deviation in heterozygosity depicted. Results We identified 942 variants, including 888 SNPs, 43 insertion/deletion polymorphisms, and 11 microsatellite markers. Of the SNPs, 557 (63%) had been previously identified and 331 (37%) were newly discovered in the Korean population. When compared SNPs in the Korean population with those in HapMap database, 1% (or less) of SNPs in the Japanese and Chinese subpopulations and 20% of those in Caucasian and African subpopulations were significantly differentiated from the Hardy-Weinberg expectations. In addition, an analysis of the genetic diversity showed that there were no significant differences among Korean, Han Chinese and Japanese populations, but African and Caucasian populations were significantly differentiated in selected genes. Nevertheless, in the detailed analysis of genetic properties, the LD and Haplotype block patterns among the five sub-populations were substantially different from one another. Conclusion Through the resequencing of 81 osteoporosis candidate genes, 118 unknown SNPs with a minor allele frequency (MAF) > 0.05 were discovered in the Korean population. In addition, using the common SNPs between our study and HapMap, an analysis of genetic diversity and deviation in heterozygosity was performed and the polymorphisms of the above genes among the five populations were substantially differentiated from one another. Further studies of osteoporosis could utilize the polymorphisms identified in our data since they may have important implications for the selection of highly informative SNPs for future association studies. PMID:18036257

Targeted sequencing identifies genetic polymorphisms of flavin-containing monooxygenase genes contributing to susceptibility of nicotine dependence in European American and African American.

PubMed

Zhang, Tian-Xiao; Saccone, Nancy L; Bierut, Laura J; Rice, John P

2017-04-01

Smoking is a leading cause of preventable death. Early studies based on samples of twins have linked the lifetime smoking practices to genetic predisposition. The flavin-containing monooxygenase (FMO) protein family consists of a group of enzymes that metabolize drugs and xenobiotics. Both FMO1 and FMO3 were potentially susceptible genes for nicotine metabolism process. In this study, we investigated the potential of FMO genes to confer risk of nicotine dependence via deep targeted sequencing in 2,820 study subjects comprising 1,583 nicotine dependents and 1,237 controls from European American and African American. Specifically, we focused on the two genomic segments including FMO1 , FMO3 , and pseudo gene FMO6P , and aimed to investigate the potential association between FMO genes and nicotine dependence. Both common and low-frequency/rare variants were analyzed using different algorithms. The potential functional significance of SNPs with association signal was investigated with relevant bioinformatics tools. We identified different clusters of significant common variants in European (with most significant SNP rs6674596, p  =   .0004, OR = 0.67, MAF_EA = 0.14, FMO1 ) and African Americans (with the most significant SNP rs6608453, p  =   .001, OR = 0.64, MAF_AA = 0.1, FMO6P ). No significant signals were identified through haplotype-based analyses. Gene network investigation indicated that both FMO1 and FMO3 have a strong relation with a variety of genes belonging to CYP gene families (with combined score greater than 0.9). Most of the significant variants identified were SNPs located within intron regions or with unknown functional significance, indicating a need for future work to understand the underlying functional significance of these signals. Our findings indicated significant association between FMO genes and nicotine dependence. Replications of our findings in other ethnic groups were needed in the future. Most of the significant variants identified were SNPs located within intronic regions or with unknown functional significance, indicating a need for future work to understand the underlying functional significance of these signals.

CYP3A4 and CYP3A5 polymorphisms and blood pressure response to amlodipine among African-American men and women with early hypertensive renal disease.

PubMed

Bhatnagar, Vibha; Garcia, Erin P; O'Connor, Daniel T; Brophy, Victoria H; Alcaraz, John; Richard, Erin; Bakris, George L; Middleton, John P; Norris, Keith C; Wright, Jackson; Hiremath, Leena; Contreras, Gabriel; Appel, Lawrence J; Lipkowitz, Michael S

2010-01-01

To explore the association between CYP3A4 and CYP3A5 gene polymorphisms and blood pressure response to amlodipine among participants from the African-American Study of Kidney Disease and Hypertension Trial randomized to amlodipine (n = 164). Cox proportional hazards models were used to determine the risk of reaching a target mean arterial pressure (MAP) of < or =107 mm Hg by CYP3A4 (A-392G and T16090C) and CYP3A5 (A6986G) gene polymorphisms, stratified by MAP randomization group (low or usual) and controlling for other predictors for blood pressure response. Women randomized to a usual MAP goal with an A allele at CYP3A4 A-392G were more likely to reach a target MAP of 107 mm Hg. The adjusted hazard ratio (AA/AG compared to GG) with 95% confidence interval was 3.41 (1.20-9.64; p = 0.020). Among participants randomized to a lower MAP goal, those with the C allele at CYP3A4 T16090C were more likely to reach target MAP: The adjusted hazard ratio was 2.04 (1.17-3.56; p = 0.010). After adjustment for multiple testing using a threshold significance level of p = 0.016, only the CYP3A4 T16090C SNP remained significant. CYP3A5 A6986G was not associated with blood pressure response. Our findings suggest that blood pressure response to amlodipine among high-risk African-Americans appears to be determined by CYP3A4 genotypes, and sex specificity may be an important consideration. Clinical applications of CYP3A4 genotype testing for individualized treatment regimens warrant further study. Copyright (c) 2009 S. Karger AG, Basel.

CYP3A4 and CYP3A5 Polymorphisms and Blood Pressure Response to Amlodipine among African-American Men and Women with Early Hypertensive Renal Disease

PubMed Central

Bhatnagar, Vibha; Garcia, Erin P.; O’Connor, Daniel T.; Brophy, Victoria H.; Alcaraz, John; Richard, Erin; Bakris, George L.; Middleton, John P.; Norris, Keith C.; Wright, Jackson; Hiremath, Leena; Contreras, Gabriel; Appel, Lawrence J.; Lipkowitz, Michael S.

2010-01-01

Purpose To explore the association between CYP3A4 and CYP3A5 gene polymorphisms and blood pressure response to amlodipine among participants from the African-American Study of Kidney Disease and Hypertension Trial randomized to amlodipine (n = 164). Methods Cox proportional hazards models were used to determine the risk of reaching a target mean arterial pressure (MAP) of ≤107 mm Hg by CYP3A4 (A–392G and T16090C) and CYP3A5 (A6986G) gene polymorphisms, stratified by MAP randomization group (low or usual) and controlling for other predictors for blood pressure response. Results Women randomized to a usual MAP goal with an A allele at CYP3A4 A–392G were more likely to reach a target MAP of 107 mm Hg. The adjusted hazard ratio (AA/AG compared to GG) with 95% confidence interval was 3.41 (1.20–9.64; p = 0.020). Among participants randomized to a lower MAP goal, those with the C allele at CYP3A4 T16090C were more likely to reach target MAP: The adjusted hazard ratio was 2.04 (1.17–3.56; p = 0.010). After adjustment for multiple testing using a threshold significance level of p = 0.016, only the CYP3A4 T16090C SNP remained significant. CYP3A5 A6986G was not associated with blood pressure response. Conclusions Our findings suggest that blood pressure response to amlodipine among high-risk African-Americans appears to be determined by CYP3A4 genotypes, and sex specificity may be an important consideration. Clinical applications of CYP3A4 genotype testing for individualized treatment regimens warrant further study. PMID:19907160

Absence of Putative Artemisinin Resistance Mutations Among Plasmodium falciparum in Sub-Saharan Africa: A Molecular Epidemiologic Study

PubMed Central

Taylor, Steve M.; Parobek, Christian M.; DeConti, Derrick K.; Kayentao, Kassoum; Coulibaly, Sheick Oumar; Greenwood, Brian M.; Tagbor, Harry; Williams, John; Bojang, Kalifa; Njie, Fanta; Desai, Meghna; Kariuki, Simon; Gutman, Julie; Mathanga, Don P.; Mårtensson, Andreas; Ngasala, Billy; Conrad, Melissa D.; Rosenthal, Philip J.; Tshefu, Antoinette K.; Moormann, Ann M.; Vulule, John M.; Doumbo, Ogobara K.; ter Kuile, Feiko O.; Meshnick, Steven R.; Bailey, Jeffrey A.; Juliano, Jonathan J.

2015-01-01

Plasmodium falciparum parasites that are resistant to artemisinins have been detected in Southeast Asia. Resistance is associated with several polymorphisms in the parasite's K13-propeller gene. The molecular epidemiology of these artemisinin resistance genotypes in African parasite populations is unknown. We developed an assay to quantify rare polymorphisms in parasite populations that uses a pooled deep-sequencing approach to score allele frequencies, validated it by evaluating mixtures of laboratory parasite strains, and then used it to screen P. falciparum parasites from >1100 African infections collected since 2002 from 14 sites across sub-Saharan Africa. We found no mutations in African parasite populations that are associated with artemisinin resistance in Southeast Asian parasites. However, we observed 15 coding mutations, including 12 novel mutations, and limited allele sharing between parasite populations, consistent with a large reservoir of naturally occurring K13-propeller variation. Although polymorphisms associated with artemisinin resistance in P. falciparum in Southeast Asia are not prevalent in sub-Saharan Africa, numerous K13-propeller coding polymorphisms circulate in Africa. Although their distributions do not support a widespread selective sweep for an artemisinin-resistant phenotype, the impact of these mutations on artemisinin susceptibility is unknown and will require further characterization. Rapid, scalable molecular surveillance offers a useful adjunct in tracking and containing artemisinin resistance. PMID:25180240

Population Structure With Localized Haplotype Clusters

PubMed Central

Browning, Sharon R.; Weir, Bruce S.

2010-01-01

We propose a multilocus version of FST and a measure of haplotype diversity using localized haplotype clusters. Specifically, we use haplotype clusters identified with BEAGLE, which is a program implementing a hidden Markov model for localized haplotype clustering and performing several functions including inference of haplotype phase. We apply this methodology to HapMap phase 3 data. With this haplotype-cluster approach, African populations have highest diversity and lowest divergence from the ancestral population, East Asian populations have lowest diversity and highest divergence, and other populations (European, Indian, and Mexican) have intermediate levels of diversity and divergence. These relationships accord with expectation based on other studies and accepted models of human history. In contrast, the population-specific FST estimates obtained directly from single-nucleotide polymorphisms (SNPs) do not reflect such expected relationships. We show that ascertainment bias of SNPs has less impact on the proposed haplotype-cluster-based FST than on the SNP-based version, which provides a potential explanation for these results. Thus, these new measures of FST and haplotype-cluster diversity provide an important new tool for population genetic analysis of high-density SNP data. PMID:20457877

Directional and balancing selection in human beta-defensins.

PubMed

Hollox, Edward J; Armour, John A L

2008-04-16

In primates, infection is an important force driving gene evolution, and this is reflected in the importance of infectious disease in human morbidity today. The beta-defensins are key components of the innate immune system, with antimicrobial and cell signalling roles, but also reproductive functions. Here we examine evolution of beta-defensins in catarrhine primates and variation within different human populations. We show that five beta-defensin genes that do not show copy number variation in humans show evidence of positive selection in catarrhine primates, and identify specific codons that have been under selective pressure. Direct haplotyping of DEFB127 in humans suggests long-term balancing selection: there are two highly diverged haplotype clades carrying different variants of a codon that, in primates, is positively selected. For DEFB132, we show that extensive diversity, including a four-state amino acid polymorphism (valine, isoleucine, alanine and threonine at position 93), is present in hunter-gatherer populations, both African and non-African, but not found in samples from agricultural populations. Some, but not all, beta-defensin genes show positive selection in catarrhine primates. There is suggestive evidence of different selective pressures on these genes in humans, but the nature of the selective pressure remains unclear and is likely to differ between populations.

Association of genetic polymorphisms with risk of renal injury after coronary bypass graft surgery.

PubMed

Stafford-Smith, Mark; Podgoreanu, Mihai; Swaminathan, Madhav; Phillips-Bute, Barbara; Mathew, Joseph P; Hauser, Elizabeth H; Winn, Michelle P; Milano, Carmelo; Nielsen, Dahlia M; Smith, Mike; Morris, Richard; Newman, Mark F; Schwinn, Debra A

2005-03-01

Post-cardiac surgery renal dysfunction is a common, serious, multifactorial disorder, with interpatient variability predicted poorly by preoperative clinical, procedural, and biological markers. Therefore, we tested the hypothesis that selected gene variants are associated with acute renal injury, reflected by a serum creatinine level increase after cardiac surgery. One thousand six hundred seventy-one patients undergoing aortocoronary surgery were studied. Clinical covariates were recorded. DNA was isolated from preoperative blood; mass spectrometry was used for genotype analysis. A model was developed relating clinical and genetic factors to postoperative acute renal injury. A race effect was found; therefore, Caucasians and African Americans were analyzed separately. Overall, clinical factors alone account poorly for postoperative renal injury, although more so in African Americans than Caucasians. When 12 candidate polymorphisms were assessed, 2 alleles (interleukin 6 -572C and angiotensinogen 842C) showed a strong association with renal injury in Caucasians (P < 0.0001; >50% decrease in renal filtration when they present together). Using less stringent criteria for significance (0.01 > P > 0.001), 4 additional polymorphisms are identified (apolipoproteinE 448C [4], angiotensin receptor1 1166C, and endothelial nitric oxide synthase [eNOS] 894T in Caucasians; eNOS 894T and angiotensin-converting enzyme deletion and insertion in African Americans). Adding genetic to clinical factors resulted in the best model, with overall ability to explain renal injury increasing approximately 4-fold in Caucasians and doubling in African Americans (P < 0.0005). In this study, we identify genetic polymorphisms that collectively provide 2- to 4-fold improvement over preoperative clinical factors alone in explaining post-cardiac surgery renal dysfunction. From a mechanistic perspective, most identified genetic variants are associated with increased renal inflammatory and/or vasoconstrictor responses.

Increased genetic diversity of ADME genes in African Americans compared with their putative ancestral source populations and implications for Pharmacogenomics

PubMed Central

2014-01-01

Background African Americans have been treated as a representative population for African ancestry for many purposes, including pharmacogenomic studies. However, the contribution of European ancestry is expected to result in considerable differences in the genetic architecture of African American individuals compared with an African genome. In particular, the genetic admixture influences the genomic diversity of drug metabolism-related genes, and may cause high heterogeneity of drug responses in admixed populations such as African Americans. Results The genomic ancestry information of African-American (ASW) samples was obtained from data of the 1000 Genomes Project, and local ancestral components were also extracted for 32 core genes and 252 extended genes, which are associated with drug absorption, distribution, metabolism, and excretion (ADME) genes. As expected, the global genetic diversity pattern in ASW was determined by the contributions of its putative ancestral source populations, and the whole profiles of ADME genes in ASW are much closer to those in YRI than in CEU. However, we observed much higher diversity in some functionally important ADME genes in ASW than either CEU or YRI, which could be a result of either genetic drift or natural selection, and we identified some signatures of the latter. We analyzed the clinically relevant polymorphic alleles and haplotypes, and found that 28 functional mutations (including 3 missense, 3 splice, and 22 regulator sites) exhibited significantly higher differentiation between the three populations. Conclusions Analysis of the genetic diversity of ADME genes showed differentiation between admixed population and its ancestral source populations. In particular, the different genetic diversity between ASW and YRI indicated that the ethnic differences in pharmacogenomic studies are broadly existed despite that African ancestry is dominant in Africans Americans. This study should advance our understanding of the genetic basis of the drug response heterogeneity between populations, especially in the case of population admixture, and have significant implications for evaluating potential inter-population heterogeneity in drug treatment effects. PMID:24884825

Genome-wide Association Study Identifies African-Specific Susceptibility Loci in African Americans with Inflammatory Bowel Disease

PubMed Central

Brant, Steven R.; Okou, David T.; Simpson, Claire L.; Cutler, David J.; Haritunians, Talin; Bradfield, Jonathan P.; Chopra, Pankaj; Prince, Jarod; Begum, Ferdouse; Kumar, Archana; Huang, Chengrui; Venkateswaran, Suresh; Datta, Lisa W.; Wei, Zhi; Thomas, Kelly; Herrinton, Lisa J.; Klapproth, Jan-Micheal A.; Quiros, Antonio J.; Seminerio, Jenifer; Liu, Zhenqiu; Alexander, Jonathan S.; Baldassano, Robert N.; Dudley-Brown, Sharon; Cross, Raymond K.; Dassopoulos, Themistocles; Denson, Lee A.; Dhere, Tanvi A.; Dryden, Gerald W.; Hanson, John S.; Hou, Jason K.; Hussain, Sunny Z.; Hyams, Jeffrey S.; Isaacs, Kim L.; Kader, Howard; Kappelman, Michael D.; Katz, Jeffry; Kellermayer, Richard; Kirschner, Barbara S.; Kuemmerle, John F.; Kwon, John H.; Lazarev, Mark; Li, Ellen; Mack, David; Mannon, Peter; Moulton, Dedrick E.; Newberry, Rodney D.; Osuntokun, Bankole O.; Patel, Ashish S.; Saeed, Shehzad A.; Targan, Stephan R.; Valentine, John F.; Wang, Ming-Hsi; Zonca, Martin; Rioux, John D.; Duerr, Richard H.; Silverberg, Mark S.; Cho, Judy H.; Hakonarson, Hakon; Zwick, Michael E.; McGovern, Dermot P.B.; Kugathasan, Subra

2016-01-01

Background & Aims The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn’s disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. Methods We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified [IBD-U]) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P<5.0×10−8 in meta-analysis with a nominal evidence (P<.05) in each scan were considered to have genome-wide significance. Results We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance associations for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P<1.6×10−6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B, PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. Conclusions We performed a genome-wide association study of African Americans with IBD and identified loci associated with CD and UC in only this population; we also replicated loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry. PMID:27693347

Effect of Genetic African Ancestry on eGFR and Kidney Disease

PubMed Central

Nadkarni, Girish N.; Belbin, Gillian; Lotay, Vaneet; Wyatt, Christina; Gottesman, Omri; Bottinger, Erwin P.; Kenny, Eimear E.; Peter, Inga

2015-01-01

Self-reported ancestry, genetically determined ancestry, and APOL1 polymorphisms are associated with variation in kidney function and related disease risk, but the relative importance of these factors remains unclear. We estimated the global proportion of African ancestry for 9048 individuals at Mount Sinai Medical Center in Manhattan (3189 African Americans, 1721 European Americans, and 4138 Hispanic/Latino Americans by self-report) using genome-wide genotype data. CKD-EPI eGFR and genotypes of three APOL1 coding variants were available. In admixed African Americans and Hispanic/Latino Americans, serum creatinine values increased as African ancestry increased (per 10% increase in African ancestry, creatinine values increased 1% in African Americans and 0.9% in Hispanic/Latino Americans; P≤1x10−7). eGFR was likewise significantly associated with African genetic ancestry in both populations. In contrast, APOL1 risk haplotypes were significantly associated with CKD, eGFR<45 ml/min per 1.73 m2, and ESRD, with effects increasing with worsening disease states and the contribution of genetic African ancestry decreasing in parallel. Using genetic ancestry in the eGFR equation to reclassify patients as black on the basis of ≥50% African ancestry resulted in higher eGFR for 14.7% of Hispanic/Latino Americans and lower eGFR for 4.1% of African Americans, affecting CKD staging in 4.3% and 1% of participants, respectively. Reclassified individuals had electrolyte values consistent with their newly assigned CKD stage. In summary, proportion of African ancestry was significantly associated with normal-range creatinine and eGFR, whereas APOL1 risk haplotypes drove the associations with CKD. Recalculation of eGFR on the basis of genetic ancestry affected CKD staging and warrants additional investigation. PMID:25349204

Normal Genetic Variation, Cognition, and Aging

PubMed Central

Greenwood, P. M.; Parasuraman, Raja

2005-01-01

This article reviews the modulation of cognitive function by normal genetic variation. Although the heritability of “g” is well established, the genes that modulate specific cognitive functions are largely unidentified. Application of the allelic association approach to individual differences in cognition has begun to reveal the effects of single nucleotide polymorphisms on specific and general cognitive functions. This article proposes a framework for relating genotype to cognitive phenotype by considering the effect of genetic variation on the protein product of specific genes within the context of the neural basis of particular cognitive domains. Specificity of effects is considered, from genes controlling part of one receptor type to genes controlling agents of neuronal repair, and evidence is reviewed of cognitive modulation by polymorphisms in dopaminergic and cholinergic receptor genes, dopaminergic enzyme genes, and neurotrophic genes. Although allelic variation in certain genes can be reliably linked to cognition—specifically to components of attention, working memory, and executive function in healthy adults—the specificity, generality, and replicability of the effects are not fully known. PMID:15006290

CCL3L1 copy number, CCR5 genotype and susceptibility to tuberculosis.

PubMed

Carpenter, Danielle; Taype, Carmen; Goulding, Jon; Levin, Mike; Eley, Brian; Anderson, Suzanne; Shaw, Marie-Anne; Armour, John A L

2014-01-09

Tuberculosis is a major infectious disease and functional studies have provided evidence that both the chemokine MIP-1α and its receptor CCR5 play a role in susceptibility to TB. Thus by measuring copy number variation of CCL3L1, one of the genes that encode MIP-1α, and genotyping a functional promoter polymorphism -2459A > G in CCR5 (rs1799987) we investigate the influence of MIP-1α and CCR5, independently and combined, in susceptibility to clinically active TB in three populations, a Peruvian population (n = 1132), a !Xhosa population (n = 605) and a South African Coloured population (n = 221). The three populations include patients with clinically diagnosed pulmonary TB, as well as other, less prevalent forms of extrapulmonary TB. Copy number of CCL3L1 was measured using the paralogue ratio test and exhibited ranges between 0-6 copies per diploid genome (pdg) in Peru, between 0-12 pdg in !Xhosa samples and between 0-10 pdg in South African Coloured samples. The CCR5 promoter polymorphism was observed to differ significantly in allele frequency between populations (*A; Peru f = 0.67, !Xhosa f = 0.38, Coloured f = 0.48). The case-control association studies performed however find, surprisingly, no evidence for an influence of variation in genes coding for MIP-1α or CCR5 individually or together in susceptibility to clinically active TB in these populations.

Validation of a CD1b tetramer assay for studies of human mycobacterial infection or vaccination.

PubMed

Layton, Erik D; Yu, Krystle K Q; Smith, Malisa T; Scriba, Thomas J; De Rosa, Stephen C; Seshadri, Chetan

2018-07-01

CD1 tetramers loaded with lipid antigens facilitate the identification of rare lipid-antigen specific T cells present in human blood and tissue. Because CD1 proteins are structurally non-polymorphic, these tetramers can be applied to genetically diverse human populations, unlike MHC-I and MHC-II tetramers. However, there are no standardized assays to quantify and characterize lipid antigen-specific T cells present within clinical samples. We incorporated CD1b tetramers loaded with the mycobacterial lipid glucose monomycolate (GMM) into a multi-parameter flow cytometry assay. Using a GMM-specific T-cell line, we demonstrate that the assay is linear, reproducible, repeatable, precise, accurate, and has a limit of detection of approximately 0.007%. Having formally validated this assay, we performed a cross-sectional study of healthy U.S. controls and South African adolescents with and without latent tuberculosis infection (LTBI). We show that GMM-specific T cells are specifically detected in South African subjects with LTBI and not in U.S. healthy controls. This assay can be expanded to include additional tetramers or phenotypic markers to characterize GMM-specific T cells in studies of mycobacterial infection, disease, or vaccination. Copyright © 2018 Elsevier B.V. All rights reserved.

Polymorphisms in VDR gene in Tunisian postmenopausal women are associated with osteopenia phenotype.

PubMed

Sassi, R; Sahli, H; Souissi, C; Sellami, S; Ben Ammar El Gaaied, A

2015-01-01

Osteopenia is characterized by intermediate values of bone mineral density (BMD) as compared to normal and osteoporotic subjects. BMD, a surrogate phenotype for osteoporosis, is influenced in part by genetic factors. Among the genes associated with BMD, the vitamin D receptor (VDR) was the first gene studied as a potential candidate associated with BMD in adult and postmenopausal bone loss. However, results are controversial. To determine whether VDR polymorphisms ApaI and TaqI are associated with BMD, osteopenia, osteoporosis and low-impact fracture risk in North Africans, these genotypes were analyzed in 566 postmenopausal Tunisian women. In postmenopausal Tunisian women, the GT ApaI genotype seems to be protective against osteoporosis development (p = 0.02; odds ratio = 0.54). Moreover, the presence of the combined GT/TT genotype of ApaI and TaqI polymorphisms is more frequent in normal BMD women than in osteoporotic women (p = 0.00; odds ratio = 0.41). Interestingly, the GG ApaI genotype is associated with osteopenia development (p = 0.02; odds ratio = 1.86) and also the TT TaqI polymorphism (p = 0.02; odds ratio = 1.53). The GG ApaI genotype is associated with a three times risk of vertebral fracture. The ApaI polymorphism showed an association with osteopenia and low-impact vertebral fracture incidence but not with osteoporosis. The TaqI polymorphism is associated specifically with the osteopenia phenotype. The presence of the two polymorphisms increases the risk to develop osteopenia in postmenopausal Tunisian women. Osteopenia seems to be genetically determined. However, osteoporosis is the result of interaction between genetic and environmental factors.

Delimiting Allelic Imbalance of TYMS by Allele-Specific Analysis.

PubMed

Balboa-Beltrán, Emilia; Cruz, Raquel; Carracedo, Angel; Barros, Francisco

2015-07-01

Allelic imbalance of thymidylate synthase (TYMS) is attributed to polymorphisms in the 5'- and 3'-untranslated region (UTR). These polymorphisms have been related to the risk of suffering different cancers, for example leukemia, breast or gastric cancer, and response to different drugs, among which are methotrexate glutamates, stavudine, and specifically 5-fluorouracil (5-FU), as TYMS is its direct target. A vast literature has been published in relation to 5-FU, even suggesting the sole use of these polymorphisms to effectively manage 5-FU dosage. Estimates of the extent to which these polymorphisms influence in TYMS expression have in the past been based on functional analysis by luciferase assays and quantification of TYMS mRNA, but both these studies, as the association studies with cancer risk or with toxicity or response to 5-FU, are very contradictory. Regarding functional assays, the artificial genetic environment created in luciferase assay and the problems derived from quantitative polymerase chain reactions (qPCRs), for example the use of a reference gene, may have distorted the results. To avoid these sources of interference, we have analyzed the allelic imbalance of TYMS by allelic-specific analysis in peripheral blood mononuclear cells (PBMCs) from patients.Allelic imbalance in PBMCs, taken from 40 patients with suspected myeloproliferative haematological diseases, was determined by fluorescent fragment analysis (for the 3'-UTR polymorphism), Sanger sequencing and allelic-specific qPCR in multiplex (for the 5'-UTR polymorphisms).For neither the 3'- nor the 5'-UTR polymorphisms did the observed allelic imbalance exceed 1.5 fold. None of the TYMS polymorphisms is statistically associated with allelic imbalance.The results acquired allow us to deny the previously established assertion of an influence of 2 to 4 fold of the rs45445694 and rs2853542 polymorphisms in the expression of TYMS and narrow its allelic imbalance to 1.5 fold, in our population. These data circumscribe the influence of these polymorphisms in the clinical outcome of 5-FU and question their use for establishing 5-FU dosage, above all when additional genetic factors are not considered.

Residue-Specific Side-Chain Polymorphisms via Particle Belief Propagation.

PubMed

Ghoraie, Laleh Soltan; Burkowski, Forbes; Li, Shuai Cheng; Zhu, Mu

2014-01-01

Protein side chains populate diverse conformational ensembles in crystals. Despite much evidence that there is widespread conformational polymorphism in protein side chains, most of the X-ray crystallography data are modeled by single conformations in the Protein Data Bank. The ability to extract or to predict these conformational polymorphisms is of crucial importance, as it facilitates deeper understanding of protein dynamics and functionality. In this paper, we describe a computational strategy capable of predicting side-chain polymorphisms. Our approach extends a particular class of algorithms for side-chain prediction by modeling the side-chain dihedral angles more appropriately as continuous rather than discrete variables. Employing a new inferential technique known as particle belief propagation, we predict residue-specific distributions that encode information about side-chain polymorphisms. Our predicted polymorphisms are in relatively close agreement with results from a state-of-the-art approach based on X-ray crystallography data, which characterizes the conformational polymorphisms of side chains using electron density information, and has successfully discovered previously unmodeled conformations.

IL-10 -1082 A>G (rs1800896) polymorphism confers susceptibility to pulmonary tuberculosis in Caucasians but not in Asians and Africans: a meta-analysis.

PubMed

Areeshi, Mohammed Y; Mandal, Raju K; Dar, Sajad A; Jawed, Arshad; Wahid, Mohd; Lohani, Mohtashim; Panda, Aditya K; Mishra, Bhartendu N; Akhter, Naseem; Haque, Shafiul

2017-10-31

Earlier studies have shown that interlukin-10 ( IL-10 ) -1082 A>G gene polymorphism is implicated in susceptibility to pulmonary tuberculosis (PTB), but their results are inconsistent and inconclusive. In the present study, a meta-analysis was performed to analyze the potential association between IL-10 -1082 A>G gene polymorphism and PTB susceptibility. A quantitative synthesis was done using PubMed (Medline), EMBASE, and Google Scholar web databases search and meta-analysis was performed by calculating pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for all the genetic models. A total of 22 eligible studies comprising 4956 PTB cases and 6428 healthy controls were included in the analysis. We did not observe any increased or decreased risk of PTB in allelic contrast (G vs. A: P =0.985; OR = 1.001, 95% CI = 0.863-1.162), homozygous (GG vs. AA: P =0.889; OR = 1.029, 95% CI = 0.692-1.529), heterozygous (GA vs. AA: P =0.244; OR = 0.906, 95% CI = 0.767-1.070), dominant (GG + AG vs. AA: P =0.357; OR = 1.196, 95% CI = 0.817-1.752), and recessive (GG vs. AA + AG: P =0.364; OR = 0.921, 95% CI = 0.771-1.100) genetic models. Likewise, no association of IL-10 -1082 A>G polymorphism with PTB risk was observed in Asian and African population for all the genetic models. Interestingly, the dominant model (GG + AG vs. AA: P =0.004; OR = 1.694, 95% CI = 1.183-2.425) demonstrated increased risk of PTB in Caucasian population. This meta-analysis concludes that IL-10 -1082 A>G gene polymorphism is not significantly associated with overall, Asian and African population. However, this polymorphism is associated with Caucasian population. © 2017 The Author(s).

IL-10 -1082 A>G (rs1800896) polymorphism confers susceptibility to pulmonary tuberculosis in Caucasians but not in Asians and Africans: a meta-analysis

PubMed Central

Areeshi, Mohammed Y.; Mandal, Raju K.; Dar, Sajad A.; Jawed, Arshad; Wahid, Mohd; Lohani, Mohtashim; Panda, Aditya K.; Mishra, Bhartendu N.; Akhter, Naseem

2017-01-01

Background: Earlier studies have shown that interlukin-10 (IL-10) -1082 A>G gene polymorphism is implicated in susceptibility to pulmonary tuberculosis (PTB), but their results are inconsistent and inconclusive. In the present study, a meta-analysis was performed to analyze the potential association between IL-10 -1082 A>G gene polymorphism and PTB susceptibility. Methods: A quantitative synthesis was done using PubMed (Medline), EMBASE, and Google Scholar web databases search and meta-analysis was performed by calculating pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) for all the genetic models. Results: A total of 22 eligible studies comprising 4956 PTB cases and 6428 healthy controls were included in the analysis. We did not observe any increased or decreased risk of PTB in allelic contrast (G vs. A: P=0.985; OR = 1.001, 95% CI = 0.863–1.162), homozygous (GG vs. AA: P=0.889; OR = 1.029, 95% CI = 0.692–1.529), heterozygous (GA vs. AA: P=0.244; OR = 0.906, 95% CI = 0.767–1.070), dominant (GG + AG vs. AA: P=0.357; OR = 1.196, 95% CI = 0.817–1.752), and recessive (GG vs. AA + AG: P=0.364; OR = 0.921, 95% CI = 0.771–1.100) genetic models. Likewise, no association of IL-10 -1082 A>G polymorphism with PTB risk was observed in Asian and African population for all the genetic models. Interestingly, the dominant model (GG + AG vs. AA: P=0.004; OR = 1.694, 95% CI = 1.183–2.425) demonstrated increased risk of PTB in Caucasian population. Conclusions: This meta-analysis concludes that IL-10 -1082 A>G gene polymorphism is not significantly associated with overall, Asian and African population. However, this polymorphism is associated with Caucasian population. PMID:28951522

Genetic differences in human circadian clock genes among worldwide populations.

PubMed

Ciarleglio, Christopher M; Ryckman, Kelli K; Servick, Stein V; Hida, Akiko; Robbins, Sam; Wells, Nancy; Hicks, Jennifer; Larson, Sydney A; Wiedermann, Joshua P; Carver, Krista; Hamilton, Nalo; Kidd, Kenneth K; Kidd, Judith R; Smith, Jeffrey R; Friedlaender, Jonathan; McMahon, Douglas G; Williams, Scott M; Summar, Marshall L; Johnson, Carl Hirschie

2008-08-01

The daily biological clock regulates the timing of sleep and physiological processes that are of fundamental importance to human health, performance, and well-being. Environmental parameters of relevance to biological clocks include (1) daily fluctuations in light intensity and temperature, and (2) seasonal changes in photoperiod (day length) and temperature; these parameters vary dramatically as a function of latitude and locale. In wide-ranging species other than humans, natural selection has genetically optimized adaptiveness along latitudinal clines. Is there evidence for selection of clock gene alleles along latitudinal/photoperiod clines in humans? A number of polymorphisms in the human clock genes Per2, Per3, Clock, and AANAT have been reported as alleles that could be subject to selection. In addition, this investigation discovered several novel polymorphisms in the human Arntl and Arntl2 genes that may have functional impact upon the expression of these clock transcriptional factors. The frequency distribution of these clock gene polymorphisms is reported for diverse populations of African Americans, European Americans, Ghanaians, Han Chinese, and Papua New Guineans (including 5 subpopulations within Papua New Guinea). There are significant differences in the frequency distribution of clock gene alleles among these populations. Population genetic analyses indicate that these differences are likely to arise from genetic drift rather than from natural selection.

Absence of putative artemisinin resistance mutations among Plasmodium falciparum in Sub-Saharan Africa: a molecular epidemiologic study.

PubMed

Taylor, Steve M; Parobek, Christian M; DeConti, Derrick K; Kayentao, Kassoum; Coulibaly, Sheick Oumar; Greenwood, Brian M; Tagbor, Harry; Williams, John; Bojang, Kalifa; Njie, Fanta; Desai, Meghna; Kariuki, Simon; Gutman, Julie; Mathanga, Don P; Mårtensson, Andreas; Ngasala, Billy; Conrad, Melissa D; Rosenthal, Philip J; Tshefu, Antoinette K; Moormann, Ann M; Vulule, John M; Doumbo, Ogobara K; Ter Kuile, Feiko O; Meshnick, Steven R; Bailey, Jeffrey A; Juliano, Jonathan J

2015-03-01

Plasmodium falciparum parasites that are resistant to artemisinins have been detected in Southeast Asia. Resistance is associated with several polymorphisms in the parasite's K13-propeller gene. The molecular epidemiology of these artemisinin resistance genotypes in African parasite populations is unknown. We developed an assay to quantify rare polymorphisms in parasite populations that uses a pooled deep-sequencing approach to score allele frequencies, validated it by evaluating mixtures of laboratory parasite strains, and then used it to screen P. falciparum parasites from >1100 African infections collected since 2002 from 14 sites across sub-Saharan Africa. We found no mutations in African parasite populations that are associated with artemisinin resistance in Southeast Asian parasites. However, we observed 15 coding mutations, including 12 novel mutations, and limited allele sharing between parasite populations, consistent with a large reservoir of naturally occurring K13-propeller variation. Although polymorphisms associated with artemisinin resistance in P. falciparum in Southeast Asia are not prevalent in sub-Saharan Africa, numerous K13-propeller coding polymorphisms circulate in Africa. Although their distributions do not support a widespread selective sweep for an artemisinin-resistant phenotype, the impact of these mutations on artemisinin susceptibility is unknown and will require further characterization. Rapid, scalable molecular surveillance offers a useful adjunct in tracking and containing artemisinin resistance. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Evolutionary context for the association of γ-globin, serum uric acid, and hypertension in African Americans.

PubMed

Shriner, Daniel; Kumkhaek, Chutima; Doumatey, Ayo P; Chen, Guanjie; Bentley, Amy R; Charles, Bashira A; Zhou, Jie; Adeyemo, Adebowale; Rodgers, Griffin P; Rotimi, Charles N

2015-11-05

Hyperuricemia and associated cardio-metabolic disorders are more prevalent in African Americans than in European Americans. We used genome-wide admixture mapping and association testing to identify loci with ancestry effects on serum uric acid levels. We analyzed 1,976 African Americans from Washington, D.C, including 1,322 individuals from 328 pedigrees and 654 unrelated individuals, enrolled in the Howard University Family Study. We performed admixture mapping and genome-wide association testing using ~800 k autosomal single-nucleotide polymorphisms (SNPs). We performed fine mapping by dense genotyping. We assessed functionality by a combination of bioinformatic annotation, reporter gene assays, and gel shift experiments. We also analyzed 12,641 individuals enrolled in the National Health and Nutrition Examination Survey. We detected a genome-wide significant locus on chromosome 11p15.4 at which serum uric acid levels increased with increasing African ancestry, independent of kidney function. Fine-mapping identified two independent signals in the β-globin locus. The ancestral allele at SNP rs2855126, located upstream of the hemoglobin, gamma A gene HBG1, was associated with increased serum uric acid levels and higher expression of a reporter gene relative to the derived allele. Hyperuricemia was associated with increased risk of hypertension in 3,767 African Americans (Odds Ratio = 2.48, p = 2.71 × 10(-19)). Given that increased expression of γ-globin leads to increased levels of fetal hemoglobin which confers protection against malaria, we hypothesize that evolution in Africa of protection against malaria may have occurred at the cost of increased serum uric acid levels, contributing to the high rates of hyperuricemia and associated cardio-metabolic disorders observed in African Americans.

Most common single-nucleotide polymorphisms associated with rheumatoid arthritis in persons of European ancestry confer risk of rheumatoid arthritis in African Americans.

PubMed

Hughes, Laura B; Reynolds, Richard J; Brown, Elizabeth E; Kelley, James M; Thomson, Brian; Conn, Doyt L; Jonas, Beth L; Westfall, Andrew O; Padilla, Miguel A; Callahan, Leigh F; Smith, Edwin A; Brasington, Richard D; Edberg, Jeffrey C; Kimberly, Robert P; Moreland, Larry W; Plenge, Robert M; Bridges, S Louis

2010-12-01

Large-scale genetic association studies have identified >20 rheumatoid arthritis (RA) risk alleles among individuals of European ancestry. The influence of these risk alleles has not been comprehensively studied in African Americans. We therefore sought to examine whether these validated RA risk alleles are associated with RA risk in an African American population. Twenty-seven candidate single-nucleotide polymorphisms (SNPs) were genotyped in 556 autoantibody-positive African Americans with RA and 791 healthy African American control subjects. Odds ratios (ORs) and 95% confidence intervals (95% CIs) for each SNP were compared with previously published ORs for RA patients of European ancestry. We then calculated a composite genetic risk score (GRS) for each individual based on the sum of all risk alleles. Overlap of the ORs and 95% CIs between the European and African American populations was observed for 24 of the 27 candidate SNPs. Conversely, 3 of the 27 SNPs (CCR6 rs3093023, TAGAP rs394581, and TNFAIP3 rs6920220) demonstrated ORs in the opposite direction from those reported for RA patients of European ancestry. The GRS analysis indicated a small but highly significant probability that African American patients relative to control subjects were enriched for the risk alleles validated in European RA patients (P = 0.00005). The majority of RA risk alleles previously validated for RA patients of European ancestry showed similar ORs in our population of African Americans with RA. Furthermore, the aggregate GRS supports the hypothesis that these SNPs are risk alleles for RA in the African American population. Future large-scale genetic studies are needed to validate these risk alleles and identify novel RA risk alleles in African Americans. Copyright © 2010 by the American College of Rheumatology.

The Evolution and Functional Impact of Human Deletion Variants Shared with Archaic Hominin Genomes

PubMed Central

Lin, Yen-Lung; Pavlidis, Pavlos; Karakoc, Emre; Ajay, Jerry; Gokcumen, Omer

2015-01-01

Allele sharing between modern and archaic hominin genomes has been variously interpreted to have originated from ancestral genetic structure or through non-African introgression from archaic hominins. However, evolution of polymorphic human deletions that are shared with archaic hominin genomes has yet to be studied. We identified 427 polymorphic human deletions that are shared with archaic hominin genomes, approximately 87% of which originated before the Human–Neandertal divergence (ancient) and only approximately 9% of which have been introgressed from Neandertals (introgressed). Recurrence, incomplete lineage sorting between human and chimp lineages, and hominid-specific insertions constitute the remaining approximately 4% of allele sharing between humans and archaic hominins. We observed that ancient deletions correspond to more than 13% of all common (>5% allele frequency) deletion variation among modern humans. Our analyses indicate that the genomic landscapes of both ancient and introgressed deletion variants were primarily shaped by purifying selection, eliminating large and exonic variants. We found 17 exonic deletions that are shared with archaic hominin genomes, including those leading to three fusion transcripts. The affected genes are involved in metabolism of external and internal compounds, growth and sperm formation, as well as susceptibility to psoriasis and Crohn’s disease. Our analyses suggest that these “exonic” deletion variants have evolved through different adaptive forces, including balancing and population-specific positive selection. Our findings reveal that genomic structural variants that are shared between humans and archaic hominin genomes are common among modern humans and can influence biomedically and evolutionarily important phenotypes. PMID:25556237

Interleukin 12B (IL12B) Genetic Variation and Pulmonary Tuberculosis: A Study of Cohorts from The Gambia, Guinea-Bissau, United States and Argentina

PubMed Central

Hill, Philip C.; Wejse, Christian; Bisseye, Cyrille; Olesen, Rikke; Edwards, Todd L.; Gilbert, John R.; Myers, Jamie L.; Stryjewski, Martin E.; Abbate, Eduardo; Estevan, Rosa; Hamilton, Carol D.; Tacconelli, Alessandra; Novelli, Giuseppe; Brunetti, Ercole; Aaby, Peter; Sodemann, Morten; Østergaard, Lars; Adegbola, Richard; Williams, Scott M.; Scott, William K.; Sirugo, Giorgio

2011-01-01

We examined whether polymorphisms in interleukin-12B (IL12B) associate with susceptibility to pulmonary tuberculosis (PTB) in two West African populations (from The Gambia and Guinea-Bissau) and in two independent populations from North and South America. Nine polymorphisms (seven SNPs, one insertion/deletion, one microsatellite) were analyzed in 321 PTB cases and 346 controls from Guinea-Bissau and 280 PTB cases and 286 controls from The Gambia. For replication we studied 281 case and 179 control African-American samples and 221 cases and 144 controls of European ancestry from the US and Argentina. First-stage single locus analyses revealed signals of association at IL12B 3′ UTR SNP rs3212227 (unadjusted allelic p = 0.04; additive genotypic p = 0.05, OR = 0.78, 95% CI [0.61–0.99]) in Guinea-Bissau and rs11574790 (unadjusted allelic p = 0.05; additive genotypic p = 0.05, OR = 0.76, 95% CI [0.58–1.00]) in The Gambia. Association of rs3212227 was then replicated in African-Americans (rs3212227 allelic p = 0.002; additive genotypic p = 0.05, OR = 0.78, 95% CI [0.61–1.00]); most importantly, in the African-American cohort, multiple significant signals of association (seven of the nine polymorphisms tested) were detected throughout the gene. These data suggest that genetic variation in IL12B, a highly relevant candidate gene, is a risk factor for PTB in populations of African ancestry, although further studies will be required to confirm this association and identify the precise mechanism underlying it. PMID:21339808

Mitochondrial DNA G10398A variant is not associated with breast cancer in African-American women

PubMed Central

Setiawan, Veronica Wendy; Chu, Li-Hao; John, Esther M.; Ding, Yuan Chun; Ingles, Sue A.; Bernstein, Leslie; Press, Michael F.; Ursin, Giske; Haiman, Christopher A.; Neuhausen, Susan L

2009-01-01

Mitochondria play important roles in cellular energy production, free radical generation and apoptosis. In a previous report in Cancer Research, the mitochondrial DNA (mtDNA) G10398A (Thr → Ala) polymorphism was associated with breast cancer risk in African-American women. Here, we seek to replicate the association by genotyping the G10398A polymorphism in three established population-based case-control studies of breast cancer in African-American women. The 10398A allele was not significantly associated with risk in any of the studies [San Francisco study (542 cases, 282 controls, odds ratio (OR) = 1.73; 95% confidence interval (CI): 0.87, 3.47, P = 0.12); Multiethnic Cohort (391 cases, 460 controls, OR = 1.08; 95% CI: 0.62, 1.86, P = 0.79); CARE/LIFE study (524 cases, 236 controls, OR = 0.81; 95% CI: 0.43, 1.52, P = 0.50)]. When pooling the data across the three studies (1456 cases and 978 controls), no significant association was observed with the 10398A allele (OR = 1.14; 95% CI: 0.80, 1.62, P = 0.47, P heterogeneity=0.30). In analysis of advanced breast cancer cases (n=674), there also was no significant association (OR = 1.18; 95% CI: 0.76, 1.82, P = 0.46). Our results do not support the hypothesis that the mtDNA G10398A polymorphism is a marker of breast cancer risk in African Americans as previously reported. PMID:18262047

Relationship between Hysterectomy and Admixture in African American Women

PubMed Central

Qi, Lihong; Nassir, Rami; Kosoy, Roman; Garcia, Lorena; Waetjen, L. Elaine; Ochs-Balcom, Heather M.; Gass, Margery; Robbins, John; Seldin, Michael F

2013-01-01

Objective Most studies suggest that hysterectomies are more common in African Americans than in other ethnic groups. To assess this ethnic surgical disparity in a novel way, our main goal was to determine whether admixture (the proportion of sub-Saharan African or European origin in individuals) is associated with hysterectomy frequency in African American women in the Women’s Health Initiative (WHI). Study Design In this retrospective study, we used ancestry informative single nucleotide polymorphisms (SNPs) to estimate admixture proportions in >10,000 African American women from the WHI. Logistic regression models were used to assess the association between admixture and self-reported history of hysterectomy with and without controlling for relevant covariates. Multinomial logistic regression models were used to assess the association between admixture and self-reported age of hysterectomy. We also considered other potential risk factors (adiposity, hypertension, and education) for hysterectomy accounting for admixture. Results African admixture was a strong risk factor after adjusting for multiple covariates (OR 1.85, P<.0001). The admixture risk for hysterectomy was highest for those performed in the 35–39 age range (OR 3.08, P<.0001) and least evident in oldest ages (45 or older). Our analyses also suggest that adiposity, hypertension and education were independently associated with hysterectomy in this population group. Conclusion These results suggest that higher African admixture is associated with higher frequencies of hysterectomy and that genetic studies specifically targeting African American women and diseases associated with hysterectomy may be especially useful in understanding the pathogenesis and underlying cause of this disparity in health outcome. PMID:23333549

Antiretroviral therapy modifies the genetic effect of known type 2 diabetes-associated risk variants in HIV-infected women.

PubMed

Frasco, Melissa A; Karim, Roksana; Van Den Berg, David; Watanabe, Richard M; Anastos, Kathryn; Cohen, Mardge; Gange, Stephen J; Gustafson, Deborah R; Liu, Chenglong; Tien, Phyllis C; Mack, Wendy J; Pearce, Celeste L

2014-07-31

Type 2 diabetes mellitus incidence is increased in HIV-infected persons. We examined the associations of diabetes mellitus with known diabetes mellitus-risk alleles from the general population in the context of HIV infection, and explored effect modification by combination antiretroviral therapy (cART). The Women's Interagency HIV Study is a prospective cohort of HIV-infected women. Seventeen European-derived diabetes mellitus-risk polymorphisms were genotyped in the eligible participants of the Women's Interagency HIV Study. Analyses were run separately for non-African Americans (Whites, Hispanics, Asians, and other; n = 378, 49 with incident diabetes mellitus) and African Americans (n = 591, 49 with incident diabetes mellitus). Cox proportional-hazards models were fit to estimate hazard ratios for diabetes mellitus overall and within strata of cART. In non-African Americans, heterogeneity across cART regimen was observed for nine of the 14 polymorphisms (phet < 0.05). One polymorphism was statistically significantly inversely associated with diabetes mellitus risk among women taking two nucleotide reverse transcriptase inhibitors (NRTIs) + non-nucleotide reverse transcriptase inhibitor (NNRTI). Five polymorphisms were statistically significantly associated with diabetes mellitus among women treated with at least two NRTIs + at least one protease inhibitor and one polymorphism was associated with diabetes mellitus among those treated with at least three NRTIs ± NNRTI. The hazard ratio per risk allele for IGF2BP2 rs1470579 was 2.67 (95% confidence interval 1.67-4.31) for women taking cART with at least two NRTIs + at least one protease inhibitor and 2.45 (95% confidence interval 1.08-5.53) in women taking at least three NRTIs ± NNRTI (phet = 2.50 × 10⁻³). No such associations were observed in the African Americans. Genetic susceptibility to diabetes mellitus, based on the variants studied, is substantially elevated among HIV-infected women using cART containing three or more NRTI/protease inhibitor components. A personalized medicine approach to cART selection may be indicated for HIV-infected persons carrying these diabetes mellitus-risk variants.

Analyses of genome wide association data, cytokines, and gene expression in African-Americans with benign ethnic neutropenia

PubMed Central

Shriner, Daniel; Ramos, Edward; Chin, Kyung; Srivastava, Kshitij; Zakai, Neil A.; Cushman, Mary; McClure, Leslie A.; Howard, Virginia; Flegel, Willy A.; Rotimi, Charles N.; Rodgers, Griffin P.

2018-01-01

Background Benign ethnic neutropenia (BEN) is a hematologic condition associated with people of African ancestry and specific Middle Eastern ethnic groups. Prior genetic association studies in large population showed that rs2814778 in Duffy Antigen Receptor for Chemokines (DARC) gene, specifically DARC null red cell phenotype, was associated with BEN. However, the mechanism of this red cell phenotype leading to low white cell count remained elusive. Methods We conducted an extreme phenotype design genome-wide association study (GWAS), analyzed ~16 million single nucleotide polymorphisms (SNP) in 1,178 African-Americans individuals from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study and replicated from 819 African-American participants in the Atherosclerosis Risk in Communities (ARIC) study. Conditional analyses on rs2814778 were performed to identify additional association signals on chromosome 1q22. In a separate cohort of healthy individuals with and without BEN, whole genome gene expression from peripheral blood neutrophils were analyzed for DARC. Results We confirmed that rs2814778 in DARC was associated with BEN (p = 4.09×10−53). Conditioning on rs2814778 abolished other significant chromosome 1 associations. Inflammatory cytokines (IL-2, 6, and 10) in participants in the Howard University Family Study (HUFS) and Multi-Ethnic Study in Atherosclerosis (MESA) showed similar levels in individuals homozygous for the rs2814778 allele compared to others, indicating cytokine sink hypothesis played a minor role in leukocyte homeostasis. Gene expression in neutrophils of individuals with and without BEN was also similar except for low DARC expression in BEN, suggesting normal function. BEN neutrophils had slightly activated profiles in leukocyte migration and hematopoietic stem cell mobilization pathways (expression fold change <2). Conclusions These results in humans support the notion of DARC null erythroid progenitors preferentially differentiating to myeloid cells, leading to activated DARC null neutrophils egressing from circulation to the spleen, and causing relative neutropenia. Collectively, these human data sufficiently explained the mechanism DARC null red cell phenotype causing BEN and further provided a biologic basis that BEN is clinically benign. PMID:29596498

Analyses of genome wide association data, cytokines, and gene expression in African-Americans with benign ethnic neutropenia.

PubMed

Charles, Bashira A; Hsieh, Matthew M; Adeyemo, Adebowale A; Shriner, Daniel; Ramos, Edward; Chin, Kyung; Srivastava, Kshitij; Zakai, Neil A; Cushman, Mary; McClure, Leslie A; Howard, Virginia; Flegel, Willy A; Rotimi, Charles N; Rodgers, Griffin P

2018-01-01

Benign ethnic neutropenia (BEN) is a hematologic condition associated with people of African ancestry and specific Middle Eastern ethnic groups. Prior genetic association studies in large population showed that rs2814778 in Duffy Antigen Receptor for Chemokines (DARC) gene, specifically DARC null red cell phenotype, was associated with BEN. However, the mechanism of this red cell phenotype leading to low white cell count remained elusive. We conducted an extreme phenotype design genome-wide association study (GWAS), analyzed ~16 million single nucleotide polymorphisms (SNP) in 1,178 African-Americans individuals from the Reasons for Geographic and Racial Differences in Stroke (REGARDS) study and replicated from 819 African-American participants in the Atherosclerosis Risk in Communities (ARIC) study. Conditional analyses on rs2814778 were performed to identify additional association signals on chromosome 1q22. In a separate cohort of healthy individuals with and without BEN, whole genome gene expression from peripheral blood neutrophils were analyzed for DARC. We confirmed that rs2814778 in DARC was associated with BEN (p = 4.09×10-53). Conditioning on rs2814778 abolished other significant chromosome 1 associations. Inflammatory cytokines (IL-2, 6, and 10) in participants in the Howard University Family Study (HUFS) and Multi-Ethnic Study in Atherosclerosis (MESA) showed similar levels in individuals homozygous for the rs2814778 allele compared to others, indicating cytokine sink hypothesis played a minor role in leukocyte homeostasis. Gene expression in neutrophils of individuals with and without BEN was also similar except for low DARC expression in BEN, suggesting normal function. BEN neutrophils had slightly activated profiles in leukocyte migration and hematopoietic stem cell mobilization pathways (expression fold change <2). These results in humans support the notion of DARC null erythroid progenitors preferentially differentiating to myeloid cells, leading to activated DARC null neutrophils egressing from circulation to the spleen, and causing relative neutropenia. Collectively, these human data sufficiently explained the mechanism DARC null red cell phenotype causing BEN and further provided a biologic basis that BEN is clinically benign.

APOL1 Genotype, Kidney and Cardiovascular Disease, and Death in Older Adults.

PubMed

Mukamal, Kenneth J; Tremaglio, Joseph; Friedman, David J; Ix, Joachim H; Kuller, Lewis H; Tracy, Russell P; Pollak, Martin R

2016-02-01

We sought to evaluate the cardiovascular impact of coding variants in the apolipoprotein L1 gene APOL1 that protect against trypanosome infection but have been associated with kidney disease among African Americans. As part of the Cardiovascular Health Study, a population-based cohort of Americans aged ≥65 years, we genotyped APOL1 polymorphisms rs73885319 and rs71785153 and examined kidney function, subclinical atherosclerosis, and incident cardiovascular disease and death over 13 years of follow-up among 91 African Americans with 2 risk alleles, 707 other African Americans, and 4964 white participants. The high-risk genotype with 2 risk alleles was associated with 2-fold higher levels of albuminuria and lower ankle-brachial indices but similar carotid intima-media thickness among African Americans. Median survival among high-risk African Americans was 9.9 years (95% confidence interval [CI], 8.7-11.9), compared with 13.6 years (95% CI, 12.5-14.3) among other African Americans and 13.3 years (95% CI, 13.0-13.6) among whites (P=0.03). The high-risk genotype was also associated with increased risk for incident myocardial infarction (adjusted hazard ratio 1.8; 95% CI, 1.1-3.0) and mortality (adjusted hazard ratio 1.3; 95% CI 1.0-1.7). Albuminuria and risk for myocardial infarction and mortality were nearly identical between African Americans with 0 to 1 risk alleles and whites. APOL1 genotype is associated with albuminuria, subclinical atherosclerosis, incident myocardial infarction, and mortality in older African Americans. African Americans without 2 risk alleles do not differ significantly in risk of myocardial infarction or mortality from whites. APOL1 trypanolytic variants may account for a substantial proportion of the excess risk of chronic disease in African Americans. © 2015 American Heart Association, Inc.

Angiotensin-converting enzyme gene polymorphism predicts the time-course of blood pressure response to angiotensin converting enzyme inhibition in the AASK trial

PubMed Central

Bhatnagar, Vibha; O’Connor, Daniel T.; Schork, Nicholas J.; Salem, Rany M.; Nievergelt, Caroline M.; Rana, Brinda K.; Smith, Douglas W.; Bakris, George L.; Middleton, John P.; Norris, Keith C.; Wright, Jackson T.; Cheek, Deanna; Hiremath, Leena; Contreras, Gabriel; Appel, Lawrence J.; Lipkowitz, Michael S.

2009-01-01

Objective It has yet to be determined whether genotyping at the angiotensin-converting enzyme (ACE) locus is predictive of blood pressure response to an ACE inhibitor. Methods Participants from the African American Study of Kidney Disease and Hypertension trial randomized to the ACE inhibitor ramipril (n = 347) were genotyped at three polymorphisms on ACE, just downstream from the ACE insertion/deletion polymorphism (Ins/Del): G12269A, C17888T, and G20037A. Time to reach target mean arterial pressure (≤ 107 mmHg) was analyzed by genotype and ACE haplotype using Kaplan–Meier survival curves and Cox proportional hazard models. Results Individuals with a homozygous genotype at G12269A responded significantly faster than those with a heterozygous genotype; the adjusted (average number of medications and baseline mean arterial pressure) hazard ratio (homozygous compared to heterozygous genotype) was 1.86 (95% confidence limits 1.32–3.23; P < 0.001 for G12269A genotype). The adjusted hazard ratio for participants with homozygous ACE haplotypes compared to those heterozygous ACE haplotypes was 1.40 (1.13–1.75; P = 0.003 for haplotype). The ACE genotype effects were specific for ACE inhibition (i.e., not seen among those randomized to a calcium channel blocker), and were independent of population stratification. Conclusions African-Americans with a homozygous genotype at G12269A or homozygous ACE haplotypes responded to ramipril significantly faster than those with a heterozygous genotype or heterozygous haplotypes, suggesting that heterosis may be an important determinant of responsiveness to an ACE inhibitor. These associations may be a result of biological activity of this polymorphism, or of linkage disequilibrium with nearby variants such as the ACE Ins/Del, perhaps in the regulation of ACE splicing. PMID:17885551

Evaluation of the influence of alcohol dehydrogenase polymorphisms on alcohol elimination rates in African Americans.

PubMed

Marshall, Vanessa J; Ramchandani, Vijay A; Kalu, Nnenna; Kwagyan, John; Scott, Denise M; Ferguson, Clifford L; Taylor, Robert E

2014-01-01

The relationship between alcohol dehydrogenase (ADH) polymorphisms and alcohol use disorders in populations of African descent has not been clearly established. This study examined the effect of ADH1B polymorphisms on alcohol metabolism and subjective response, following intravenous (IV) alcohol administration, and the influence of gender, recent drinking history, and family history of alcoholism (FHA), in nondependent African American drinkers. The sample included eighty-seven 21- to 35-year-old, light social drinkers of African descent. Participants included 39 sib pairs, 2 sibships with 3 siblings each, and 3 individuals who were not part of a sibship. Participants received infusions via the use of the clamp method that refers to the goal of controlling breath alcohol concentration in 2 randomized sessions at 0.06 g% ethanol and 0 mg% (placebo), and a battery of subjective scales at predefined time points. Dependent measures included alcohol elimination rates (AERs), alcohol disappearance rates (ADRs), subjective measures peak scores, and area under the curve. General linear model and mixed models were performed to examine the relationship between ADH1B genotype, dependent measures, and influence of covariates. Participants with ADH1B1/1 genotypes showed higher number of drinks (p = 0.023) and drinks per drinking day (p = 0.009) compared with the persons with ADH1B1/3 genotype. AER (adjusted for body weight) was higher in ADH1B*1 homozygotes (p = 0.045) compared with ADH1B1/3 heterozygotes. ADR differed significantly between males and females (p = 0.002), regardless of body weight (p = 0.004) and lean body mass (p < 0.001) adjustments. Although a few subjective measures differed across genotype, all measures were higher in alcohol sessions compared with placebo sessions (p < 0.001). These observations were mediated by drinks per drinking day, gender, and FHA. ADH1B polymorphism had a marginal effect on alcohol pharmacokinetics following IV alcohol administration in nondependent drinkers of African descent. Session (alcohol vs. placebo) and ADH1B genotype did, however, influence subjective response to alcohol with some variation by gender, FHA, and drinks per drinking day. Copyright © 2013 by the Research Society on Alcoholism.

Novel single nucleotide polymorphism associations with colorectal cancer on chromosome 8q24 in African and European Americans

PubMed Central

Kupfer, Sonia S.; Torres, Jada Benn; Hooker, Stanley; Anderson, Jeffrey R.; Skol, Andrew D.; Ellis, Nathan A.; Kittles, Rick A.

2009-01-01

Regions on chromosome 8q24 harbor susceptibility alleles for multiple cancers including colorectal (region 3) and prostate cancer (regions 1–4). The objectives of the present study were (i) to test whether single-nucleotide polymorphisms (SNPs) in region 4 are associated with colorectal cancer (CRC) in European or African Americans; (ii) to test whether 8q24 SNPs previously shown to be associated with colorectal and prostate cancer also show association in our multiethnic series and (iii) to test for association between 100 ancestry informative markers (AIMs) and CRC in both the African American and European American cohorts. In total, we genotyped nine markers on 8q24 and 100 unlinked AIMs in 569 CRC cases and 439 controls (490 European Americans and 518 African Americans) obtained retrospectively from a hospital-based sample. We found rs7008482 in 8q24 region 4 to be significantly associated with CRC in European Americans (P = 0.03). Also in region 4, we found that a second SNP, rs16900305, trended toward association with CRC in African Americans. The rs6983267 in region 3, previously implicated in CRC risk, trended toward association with disease in European Americans but not in African Americans. Finally, none of the 100 AIMs tested for association reached statistical significance after correction for multiple hypothesis testing. In summary, these results are evidence that 8q24 region 4 contains novel CRC-associated alleles in European and African Americans. PMID:19520795

African American race but not genome-wide ancestry is negatively associated with atrial fibrillation among postmenopausal women in the Women's Health Initiative.

PubMed

Perez, Marco V; Hoffmann, Thomas J; Tang, Hua; Thornton, Timothy; Stefanick, Marcia L; Larson, Joseph C; Kooperberg, Charles; Reiner, Alex P; Caan, Bette; Iribarren, Carlos; Risch, Neil

2013-09-01

Atrial fibrillation (AF) is the most common arrhythmia in women and is associated with higher rates of stroke and death. Rates of AF are lower in African American subjects compared with European Americans, suggesting European ancestry could contribute to AF risk. The Women's Health Initiative (WHI) Observational Study (OS) followed up 93,676 women since the mid 1990s for various cardiovascular outcomes including AF. Multivariate Cox hazard regression analysis was used to measure the association between African American race and incident AF. A total of 8,119 African American women from the WHI randomized clinical trials and OS were genotyped on the Affymetrix Human SNP Array 6.0. Genome-wide ancestry and previously reported single nucleotide polymorphisms associated with AF in European cohorts were tested for association with AF using multivariate logistic regression analyses. Self-reported African American race was associated with lower rates of AF (hazard ratio 0.43, 95% CI 0.32-0.60) in the OS, independent of demographic and clinical risk factors. In the genotyped cohort, there were 558 women with AF. By contrast, genome-wide European ancestry was not associated with AF. None of the single nucleotide polymorphisms previously associated with AF in European populations, including rs2200733, were associated with AF in the WHI African American cohort. African American race is significantly and inversely correlated with AF in postmenopausal women. The etiology of this association remains unclear and may be related to unidentified environmental differences. Larger studies are necessary to identify genetic determinants of AF in African Americans. © 2013.

Genetic association between human chitinases and lung function in COPD.

PubMed

Aminuddin, F; Akhabir, L; Stefanowicz, D; Paré, P D; Connett, J E; Anthonisen, N R; Fahy, J V; Seibold, M A; Burchard, E G; Eng, C; Gulsvik, A; Bakke, P; Cho, M H; Litonjua, A; Lomas, D A; Anderson, W H; Beaty, T H; Crapo, J D; Silverman, E K; Sandford, A J

2012-07-01

Two primary chitinases have been identified in humans--acid mammalian chitinase (AMCase) and chitotriosidase (CHIT1). Mammalian chitinases have been observed to affect the host's immune response. The aim of this study was to test for association between genetic variation in the chitinases and phenotypes related to chronic obstructive pulmonary disease (COPD). Polymorphisms in the chitinase genes were selected based on previous associations with respiratory diseases. Polymorphisms that were associated with lung function level or rate of decline in the Lung Health Study (LHS) cohort were analyzed for association with COPD affection status in four other COPD case-control populations. Chitinase activity and protein levels were also related to genotypes. In the caucasian LHS population, the baseline forced expiratory volume in one second (FEV(1)) was significantly different between the AA and GG genotypic groups of the AMCase rs3818822 polymorphism. Subjects with the GG genotype had higher AMCase protein and chitinase activity compared with AA homozygotes. For CHIT1 rs2494303, a significant association was observed between rate of decline in FEV(1) and the different genotypes. In the African American LHS population, CHIT1 rs2494303 and AMCase G339T genotypes were associated with rate of decline in FEV(1). Although a significant effect of chitinase gene alleles was found on lung function level and decline in the LHS, we were unable to replicate the associations with COPD affection status in the other COPD study groups.

Grade-specific prostate cancer associations of IGF1 (CA)19 repeats and IGFBP3-202A/C in blacks and whites.

PubMed

Hoyo, Cathrine; Grubber, Janet; Demark-Wahnefried, Wendy; Marks, Jeffrey R; Freedland, Stephen J; Jeffreys, Amy S; Grambow, Steven C; Wenham, Robert M; Walther, Philip J; Schildkraut, Joellen M

2007-07-01

Carrying the cytosine-adenosine (CA)19 repeat polymorphism in insulin-like growth factor-1 (IGF1) is associated with lower serum proteins and decreased prostate cancer risk. Carrying the -202A/C genotype in insulin-like growth factor binding protein-3 (IGFBP3) also has been associated with lower serum levels of the binding protein. However, the association between this variant and prostate cancer is inconsistent. To test the hypothesis that inconsistencies are partly due to cancer grade-specific differences in strength and direction of associations, we reanalyzed data from our previous Durham Veterans Administration Hospital study of blacks and whites comprising 47 cases (19 African Americans) with Gleason sum > or = 7, 50 cases (30 African Americans) with Gleason sum < 7 and 93 controls (49 African Americans). Compared to controls, the association between carrying the IGFBP3 C allele and prostate cancer risk was in OR(Low-Gleason) = 4.0; 95% CI: 1.4-12.3 compared to OR(High-Gleason) = 1.0; 95% CI: 0.4-2.2. Association patterns were similar in African Americans (OR(Low-Gleason) = 3.6; 95% CI: 1.0-13.2 vs. OR(High-Gleason) = 1.4; 95% CI: 0.4-2.3) and whites (OR(Low-Gleason) = 5.6; 95% CI: 0.6-49.0 vs. OR(High-Gleason) = 0.6; 95% CI: 0.2-2.2). The inverse association between carrying the IGF1 (CA)19 repeat variant did not vary by grade or ethnicity. If confirmed in larger studies, these findings support the hypothesis that the association between IGFBP3 C allele and prostate cancer is grade specific in both ethnic groups.

Grade-specific prostate cancer associations of IGF1 (CA)19 repeats and IGFBP3-202A/C in blacks and whites.

PubMed Central

Hoyo, Cathrine; Grubber, Janet; Demark-Wahnefried, Wendy; Marks, Jeffrey R.; Freedland, Stephen J.; Jeffreys, Amy S.; Grambow, Steven C.; Wenham, Robert M.; Walther, Philip J.; Schildkraut, Joellen M.

2007-01-01

Carrying the cytosine-adenosine (CA)19 repeat polymorphism in insulin-like growth factor-1 (IGF1) is associated with lower serum proteins and decreased prostate cancer risk. Carrying the -202A/C genotype in insulin-like growth factor binding protein-3 (IGFBP3) also has been associated with lower serum levels of the binding protein. However, the association between this variant and prostate cancer is inconsistent. To test the hypothesis that inconsistencies are partly due to cancer grade-specific differences in strength and direction of associations, we reanalyzed data from our previous Durham Veterans Administration Hospital study of blacks and whites comprising 47 cases (19 African Americans) with Gleason sum > or = 7, 50 cases (30 African Americans) with Gleason sum < 7 and 93 controls (49 African Americans). Compared to controls, the association between carrying the IGFBP3 C allele and prostate cancer risk was in OR(Low-Gleason) = 4.0; 95% CI: 1.4-12.3 compared to OR(High-Gleason) = 1.0; 95% CI: 0.4-2.2. Association patterns were similar in African Americans (OR(Low-Gleason) = 3.6; 95% CI: 1.0-13.2 vs. OR(High-Gleason) = 1.4; 95% CI: 0.4-2.3) and whites (OR(Low-Gleason) = 5.6; 95% CI: 0.6-49.0 vs. OR(High-Gleason) = 0.6; 95% CI: 0.2-2.2). The inverse association between carrying the IGF1 (CA)19 repeat variant did not vary by grade or ethnicity. If confirmed in larger studies, these findings support the hypothesis that the association between IGFBP3 C allele and prostate cancer is grade specific in both ethnic groups. PMID:17668637

Association of Matrix Metalloproteinase-1 Polymorphisms with Risk of COPD and Lung Cancer and Survival in Lung Cancer

PubMed Central

ENEWOLD, LINDSEY; MECHANIC, LEAH E.; BOWMAN, ELISE D.; PLATZ, ELIZABETH A.; ALBERG, ANTHONY J.

2013-01-01

Background The primary risk factor for chronic obstructive pulmonary disease (COPD) and non-small cell lung cancer (NSCLC) is cigarette smoking but shared susceptibility factors, such as variations in the matrix metalloproteinase-1 (MMP1) gene, may also underlie both diseases. Materials and Methods Cases with prevalent COPD (n=167), incident NSCLC (n=242), or prevalent COPD plus incident NSCLC (n=128) were compared to disease-free controls (n=338) to assess six MMP1 polymorphisms. The association between these polymorphisms and survival in NSCLC was also evaluated. Results Rs11292517 among African-Americans [odds ratio (OR)=5.48, 95% confidence interval (CI)=1.17–25.72] and rs2071230 among Caucasians (OR=2.51, 95% CI=1.09–5.77) appeared to be associated with NSCLC risk in the presence of COPD. Rs470558 appeared to be associated with survival in NSCLC among African-Americans (hazard ratio=3.94; 95%CI=1.14–13.63). No associations remained after adjusting for multiple comparisons. Conclusion Polymorphisms in MMP1 were not consistently associated with prevalent COPD or incident NSCLC nor with survival in NSCLC. PMID:22993337

Pharmacogenomics of warfarin in populations of African descent

PubMed Central

Suarez-Kurtz, Guilherme; Botton, Mariana R

2013-01-01

Warfarin is the most commonly prescribed oral anticoagulant worldwide despite its narrow therapeutic index and the notorious inter- and intra-individual variability in dose required for the target clinical effect. Pharmacogenetic polymorphisms are major determinants of warfarin pharmacokinetic and dynamics and included in several warfarin dosing algorithms. This review focuses on warfarin pharmacogenomics in sub-Saharan peoples, African Americans and admixed Brazilians. These ‘Black’ populations differ in several aspects, notably their extent of recent admixture with Europeans, a factor which impacts on the frequency distribution of pharmacogenomic polymorphisms relevant to warfarin dose requirement for the target clinical effect. Whereas a small number of polymorphisms in VKORC1 (3673G > A, rs9923231), CYP2C9 (alleles *2 and *3, rs1799853 and rs1057910, respectively) and arguably CYP4F2 (rs2108622), may capture most of the pharmacogenomic influence on warfarin dose variance in White populations, additional polymorphisms in these, and in other, genes (e.g. CALU rs339097) increase the predictive power of pharmacogenetic warfarin dosing algorithms in the Black populations examined. A personalized strategy for initiation of warfarin therapy, allowing for improved safety and cost-effectiveness for populations of African descent must take into account their pharmacogenomic diversity, as well as socio-economical, cultural and medical factors. Accounting for this heterogeneity in algorithms that are ‘friendly’ enough to be adopted by warfarin prescribers worldwide requires gathering information from trials at different population levels, but demands also a critical appraisal of racial/ethnic labels that are commonly used in the clinical pharmacology literature but do not accurately reflect genetic ancestry and population diversity. PMID:22676711

Role of Assay Type in Determining Free 25-Hydroxyvitamin D Levels in Diverse Populations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielson, Carrie M.; Jones, Kerry S.; Chun, Rene F.

Serum 25-hydroxyvitamin D (25OHD) is the most frequently used marker of vitamin D status. Low 25OHD is associated with bone loss, fractures {Cauley, 2010 #1516;Ensrud, 2009 #1517}, and other adverse health outcomes {Theodoratou, 2014 #1518}. Most extra renal tissues only have access to free 25OHD, and free 25OHD concentration is thus a plausible biomarker of 25OHD availability and function {Johnsen, 2014 #1443;Chun, 2014 #1343}. Stronger associations with free or bioavailable 25OHD than with total 25OHD were reported for serum calcium, parathyroid hormone (PTH) {Bhan, 2012 #1124} and bone mineral density (BMD) {Powe, 2011 #1129}. These findings have led to themore » suggestion that free or bioavailable 25OHD may provide a more clinically relevant measure of tissue 25OHD availability and vitamin D status {Powe, 2013 #1369; Holick NEJM 2013 editorial}. The US Preventive Services Task Force (LeFevre 2015) recently pointed to the gap in research regarding bioavailable and free 25OHD and noted the possibility that these may be better markers of tissue 25OHD availability. Free 25OHD is conventionally calculated from the concentrations of total 25OHD, vitamin D binding protein (DBP) and albumin, with or without a factor accounting for DBP genotype-specific binding affinities {Bouillon, 1981 #1207;Chun, 2012 #1143; Powe, 2011 #1129;Johnsen, 2014 #1443}. DBP—or Group specific component (GC) {Hirschfeld, 1959 #1468}—polymorphisms (rs4588 and rs7041) give rise to three major polymorphic isoforms of DBP, GC-1F, GC-1S and GC-2, the frequencies of which differ globally, with GC-1F alleles more common in populations of African descent {Kambou, 1986 #1122}. Although DBP is a primary component of free and bioavailable 25OHD calculations, substantial variation in DBP between assays has been noted (Powe suggest to cite here previous publications as in previous version of this Ms). Using DBP measured by a monoclonal antibody Powe et al. {Powe, 2013 #1369} concluded that calculated free 25OHD in African-Americans was equal or higher than in US whites, questioning the implications of low total 25OHD concentrations in African Americans (Holick 2013). This idea gained widespread attention in medical and lay press {LeFevre, 2015 #1598; Bhan, 2014 #1485; Durazo-Arvizu, 2014 #1519}, and many others) and may have important implications for nutrional supplementation policy. To better understand the importance of free 25OHD estimates, and its racial differences, we conducted studies in cohorts based in the US, UK and The Gambia that included participants of African and European ancestry known to differ in GC genotype distribution. We characterized the molecular forms of circulating DBP through comparison of several DBP assays and DBP peptide proteomic analysis, to obtain both calculated and directly measured free 25OHD by geographical region, race and GC genotype.« less

Ancient Genetic Signatures of Orang Asli Revealed by Killer Immunoglobulin-Like Receptor Gene Polymorphisms

PubMed Central

NurWaliyuddin, Hanis Z. A.; Norazmi, Mohd N.; Edinur, Hisham A.; Chambers, Geoffrey K.; Panneerchelvam, Sundararajulu; Zafarina, Zainuddin

2015-01-01

The aboriginal populations of Peninsular Malaysia, also known as Orang Asli (OA), comprise three major groups; Semang, Senoi and Proto-Malays. Here, we analyzed for the first time KIR gene polymorphisms for 167 OA individuals, including those from four smallest OA subgroups (Che Wong, Orang Kanaq, Lanoh and Kensiu) using polymerase chain reaction-sequence specific primer (PCR-SSP) analyses. The observed distribution of KIR profiles of OA is heterogenous; Haplotype B is the most frequent in the Semang subgroups (especially Batek) while Haplotype A is the most common type in the Senoi. The Semang subgroups were clustered together with the Africans, Indians, Papuans and Australian Aborigines in a principal component analysis (PCA) plot and shared many common genotypes (AB6, BB71, BB73 and BB159) observed in these other populations. Given that these populations also display high frequencies of Haplotype B, it is interesting to speculate that Haplotype B may be generally more frequent in ancient populations. In contrast, the two Senoi subgroups, Che Wong and Semai are displaced toward Southeast Asian and African populations in the PCA scatter plot, respectively. Orang Kanaq, the smallest and the most endangered of all OA subgroups, has lost some degree of genetic variation, as shown by their relatively high frequency of the AB2 genotype (0.73) and a total absence of KIR2DL2 and KIR2DS2 genes. Orang Kanaq tradition that strictly prohibits intermarriage with outsiders seems to have posed a serious threat to their survival. This present survey is a demonstration of the value of KIR polymorphisms in elucidating genetic relationships among human populations. PMID:26565719

The power of social networks and social support in promotion of physical activity and body mass index among African American adults.

PubMed

Flórez, Karen R; Richardson, Andrea S; Ghosh-Dastidar, Madhumita Bonnie; Troxel, Wendy; DeSantis, Amy; Colabianchi, Natalie; Dubowitz, Tamara

2018-04-01

Social support and social networks can elucidate important structural and functional aspects of social relationships that are associated with health-promoting behaviors, including Physical Activity (PA) and weight. A growing number of studies have investigated the relationship between social support, social networks, PA and obesity specifically among African Americans; however, the evidence is mixed and many studies focus exclusively on African American women. Most studies have also focused on either functional or structural aspects of social relationships (but not both) and few have objectively measured moderate-to-vigorous physical activity (MVPA) and body mass index (BMI). Cross-sectional surveys of adult African American men and women living in two low-income predominantly African American neighborhoods in Pittsburgh, PA (N = 799) measured numerous structural features as well as functional aspects of social relationships. Specifically, structural features included social isolation, and social network size and diversity. Functional aspects included perceptions of social support for physical activity from the social network in general as well as from family and friends specifically. Height, weight, and PA were objectively measured. From these, we derived Body Mass Index (BMI) and moderate-to-vigorous physical activity (MVPA). All regression models were stratified by gender, and included age, income, education, employment, marital status, physical limitations, and a neighborhood indicator. Greater social isolation was a significant predictor of lower BMI among men only. Among women only, social isolation was significantly associated with increased MVPA whereas, network diversity was significantly associated with reduced MVPA. Future research would benefit from in-depth qualitative investigations to understand how social networks may act to influence different types of physical activity among African Americans, as well as understand how they can be possible levers for health promotion and prevention.

South-East Asian strains of Plasmodium falciparum display higher ratio of non-synonymous to synonymous polymorphisms compared to African strains

PubMed Central

Singh, Gajinder Pal; Sharma, Amit

2016-01-01

Resistance to frontline anti-malarial drugs, including artemisinin, has repeatedly arisen in South-East Asia, but the reasons for this are not understood. Here we test whether evolutionary constraints on Plasmodium falciparum strains from South-East Asia differ from African strains. We find a significantly higher ratio of non-synonymous to synonymous polymorphisms in P. falciparum from South-East Asia compared to Africa, suggesting differences in the selective constraints on P. falciparum genome in these geographical regions. Furthermore, South-East Asian strains showed a higher proportion of non-synonymous polymorphism at conserved positions, suggesting reduced negative selection. There was a lower rate of mixed infection by multiple genotypes in samples from South-East Asia compared to Africa. We propose that a lower mixed infection rate in South-East Asia reduces intra-host competition between the parasite clones, reducing the efficiency of natural selection. This might increase the probability of fixation of fitness-reducing mutations including drug resistant ones. PMID:27853513

CCL3L1 copy number, CCR5 genotype and susceptibility to tuberculosis

PubMed Central

2014-01-01

Background Tuberculosis is a major infectious disease and functional studies have provided evidence that both the chemokine MIP-1α and its receptor CCR5 play a role in susceptibility to TB. Thus by measuring copy number variation of CCL3L1, one of the genes that encode MIP-1α, and genotyping a functional promoter polymorphism -2459A > G in CCR5 (rs1799987) we investigate the influence of MIP-1α and CCR5, independently and combined, in susceptibility to clinically active TB in three populations, a Peruvian population (n = 1132), a !Xhosa population (n = 605) and a South African Coloured population (n = 221). The three populations include patients with clinically diagnosed pulmonary TB, as well as other, less prevalent forms of extrapulmonary TB. Methods and results Copy number of CCL3L1 was measured using the paralogue ratio test and exhibited ranges between 0–6 copies per diploid genome (pdg) in Peru, between 0–12 pdg in !Xhosa samples and between 0–10 pdg in South African Coloured samples. The CCR5 promoter polymorphism was observed to differ significantly in allele frequency between populations (*A; Peru f = 0.67, !Xhosa f = 0.38, Coloured f = 0.48). Conclusions The case–control association studies performed however find, surprisingly, no evidence for an influence of variation in genes coding for MIP-1α or CCR5 individually or together in susceptibility to clinically active TB in these populations. PMID:24405814

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease.

PubMed

Brant, Steven R; Okou, David T; Simpson, Claire L; Cutler, David J; Haritunians, Talin; Bradfield, Jonathan P; Chopra, Pankaj; Prince, Jarod; Begum, Ferdouse; Kumar, Archana; Huang, Chengrui; Venkateswaran, Suresh; Datta, Lisa W; Wei, Zhi; Thomas, Kelly; Herrinton, Lisa J; Klapproth, Jan-Micheal A; Quiros, Antonio J; Seminerio, Jenifer; Liu, Zhenqiu; Alexander, Jonathan S; Baldassano, Robert N; Dudley-Brown, Sharon; Cross, Raymond K; Dassopoulos, Themistocles; Denson, Lee A; Dhere, Tanvi A; Dryden, Gerald W; Hanson, John S; Hou, Jason K; Hussain, Sunny Z; Hyams, Jeffrey S; Isaacs, Kim L; Kader, Howard; Kappelman, Michael D; Katz, Jeffry; Kellermayer, Richard; Kirschner, Barbara S; Kuemmerle, John F; Kwon, John H; Lazarev, Mark; Li, Ellen; Mack, David; Mannon, Peter; Moulton, Dedrick E; Newberry, Rodney D; Osuntokun, Bankole O; Patel, Ashish S; Saeed, Shehzad A; Targan, Stephan R; Valentine, John F; Wang, Ming-Hsi; Zonca, Martin; Rioux, John D; Duerr, Richard H; Silverberg, Mark S; Cho, Judy H; Hakonarson, Hakon; Zwick, Michael E; McGovern, Dermot P B; Kugathasan, Subra

2017-01-01

The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10 -8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance. We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10 -6 ): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

PAI-1 gain-of-function genotype, factors increasing PAI-1 levels, and airway obstruction: The GALA II Cohort.

PubMed

Sherenian, M G; Cho, S H; Levin, A; Min, J-Y; Oh, S S; Hu, D; Galanter, J; Sen, S; Huntsman, S; Eng, C; Rodriguez-Santana, J R; Serebrisky, D; Avila, P C; Kalhan, R; Smith, L J; Borrell, L N; Seibold, M A; Keoki Williams, L; Burchard, E G; Kumar, R

2017-09-01

PAI-1 gain-of-function variants promote airway fibrosis and are associated with asthma and with worse lung function in subjects with asthma. We sought to determine whether the association of a gain-of-function polymorphism in plasminogen activator inhibitor-1 (PAI-1) with airway obstruction is modified by asthma status, and whether any genotype effect persists after accounting for common exposures that increase PAI-1 level. We studied 2070 Latino children (8-21y) with genotypic and pulmonary function data from the GALA II cohort. We estimated the relationship of the PAI-1 risk allele with FEV1/FVC by multivariate linear regression, stratified by asthma status. We examined the association of the polymorphism with asthma and airway obstruction within asthmatics via multivariate logistic regression. We replicated associations in the SAPPHIRE cohort of African Americans (n=1056). Secondary analysis included the effect of the at-risk polymorphism on postbronchodilator lung function. There was an interaction between asthma status and the PAI-1 polymorphism on FEV 1 /FVC (P=.03). The gain-of-function variants, genotypes (AA/AG), were associated with lower FEV 1 /FVC in subjects with asthma (β=-1.25, CI: -2.14,-0.35, P=.006), but not in controls. Subjects with asthma and the AA/AG genotypes had a 5% decrease in FEV 1 /FVC (P<.001). In asthmatics, the risk genotype (AA/AG) was associated with a 39% increase in risk of clinically relevant airway obstruction (OR=1.39, CI: 1.01, 1.92, P=.04). These associations persisted after exclusion of factors that increase PAI-1 including tobacco exposure and obesity. The decrease in the FEV 1 /FVC ratio associated with the risk genotype was modified by asthma status. The genotype increased the odds of airway obstruction by 75% within asthmatics only. As exposures known to increase PAI-1 levels did not mitigate this association, PAI-1 may contribute to airway obstruction in the context of chronic asthmatic airway inflammation. © 2017 John Wiley & Sons Ltd.

Novel genetic predictors of venous thromboembolism risk in African Americans

PubMed Central

Hernandez, Wenndy; Gamazon, Eric R.; Smithberger, Erin; O’Brien, Travis J.; Harralson, Arthur F.; Tuck, Matthew; Barbour, April; Kittles, Rick A.; Cavallari, Larisa H.

2016-01-01

Venous thromboembolism (VTE) is the third most common life-threatening cardiovascular condition in the United States, with African Americans (AAs) having a 30% to 60% higher incidence compared with other ethnicities. The mechanisms underlying population differences in the risk of VTE are poorly understood. We conducted the first genome-wide association study in AAs, comprising 578 subjects, followed by replication of highly significant findings in an independent cohort of 159 AA subjects. Logistic regression was used to estimate the association between genetic variants and VTE risk. Through bioinformatics analysis of the top signals, we identified expression quantitative trait loci (eQTLs) in whole blood and investigated the messenger RNA expression differences in VTE cases and controls. We identified and replicated single-nucleotide polymorphisms on chromosome 20 (rs2144940, rs2567617, and rs1998081) that increased risk of VTE by 2.3-fold (P < 6 × 10−7). These risk variants were found in higher frequency among populations of African descent (>20%) compared with other ethnic groups (<10%). We demonstrate that SNPs on chromosome 20 are cis-eQTLs for thrombomodulin (THBD), and the expression of THBD is lower among VTE cases compared with controls (P = 9.87 × 10−6). We have identified novel polymorphisms associated with increased risk of VTE in AAs. These polymorphisms are predominantly found among populations of African descent and are associated with THBD gene expression. Our findings provide new molecular insight into a mechanism regulating VTE susceptibility and identify common genetic variants that increase the risk of VTE in AAs, a population disproportionately affected by this disease. PMID:26888256

Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico.

PubMed

Galindo-Cardona, Alberto; Acevedo-Gonzalez, Jenny P; Rivera-Marchand, Bert; Giray, Tugrul

2013-08-06

The Africanized honey bee is one of the most spectacular invasions in the Americas. African bees escaped from apiaries in Brazil in 1956, spread over Americas and by 1994 they were reported in Puerto Rico. In contrast to other places, the oceanic island conditions in Puerto Rico may mean a single introduction and different dynamics of the resident European and new-coming Africanized bees.To examine the genetic variation of honey bee feral populations and colonies from different locations in Puerto Rico, we used eight known polymorphic microsatellite loci. In Puerto Rico, gAHB population does not show any genetic structure (Fst = 0.0783), and is best described as one honey bee population, product of hybridization of AHB and EHB. The genetic variability in this Africanized population was similar to that reported in studies from Texas. We observed that European private allele frequencies are high in all but one locus. This contrasts with mainland Africanized populations, where European allele frequencies are diminished. Two loci with European private alleles, one on Linkage Group 7, known to carry two known defensiveness Quantitative Trait Loci (QTLs), and the other on Linkage Group 1, known to carry three functionally studied genes and 11 candidate genes associated with Varroa resistance mechanisms were respectively, significantly greater or lower in European allele frequency than the other loci with European private alleles. Genetic structure of Puerto Rico gAHB differs from mainland AHB populations, probably representing evolutionary processes on the island.

Genetic structure of the gentle Africanized honey bee population (gAHB) in Puerto Rico

PubMed Central

2013-01-01

Background The Africanized honey bee is one of the most spectacular invasions in the Americas. African bees escaped from apiaries in Brazil in 1956, spread over Americas and by 1994 they were reported in Puerto Rico. In contrast to other places, the oceanic island conditions in Puerto Rico may mean a single introduction and different dynamics of the resident European and new-coming Africanized bees. To examine the genetic variation of honey bee feral populations and colonies from different locations in Puerto Rico, we used eight known polymorphic microsatellite loci. Results In Puerto Rico, gAHB population does not show any genetic structure (Fst = 0.0783), and is best described as one honey bee population, product of hybridization of AHB and EHB. The genetic variability in this Africanized population was similar to that reported in studies from Texas. We observed that European private allele frequencies are high in all but one locus. This contrasts with mainland Africanized populations, where European allele frequencies are diminished. Two loci with European private alleles, one on Linkage Group 7, known to carry two known defensiveness Quantitative Trait Loci (QTLs), and the other on Linkage Group 1, known to carry three functionally studied genes and 11 candidate genes associated with Varroa resistance mechanisms were respectively, significantly greater or lower in European allele frequency than the other loci with European private alleles. Conclusions Genetic structure of Puerto Rico gAHB differs from mainland AHB populations, probably representing evolutionary processes on the island. PMID:23915100

Single-nucleotide polymorphisms in DNA bypass polymerase genes and association with breast cancer and breast cancer subtypes among African Americans and Whites

PubMed Central

Family, Leila; Bensen, Jeannette T.; Troester, Melissa A.; Wu, Michael C.; Anders, Carey K.; Olshan, Andrew F.

2015-01-01

DNA damage recognition and repair is a complex system of genes focused on maintaining genomic stability. Recently, there has been a focus on how breast cancer susceptibility relates to genetic variation in the DNA bypass polymerases pathway. Race-stratified and subtype-specific logistic regression models were used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) for the association between 22 single-nucleotide polymorphisms (SNPs) in seven bypass polymerase genes and breast cancer risk in the Carolina Breast Cancer Study, a population-based, case–control study (1,972 cases and 1,776 controls). We used SNP-set kernel association test (SKAT) to evaluate the multi-gene, multi-locus (combined) SNP effects within bypass polymerase genes. We found similar ORs for breast cancer with three POLQ SNPs (rs487848 AG/AA vs. GG; OR = 1.31, 95 % CI 1.03–1.68 for Whites and OR = 1.22, 95 % CI 1.00–1.49 for African Americans), (rs532411 CT/TT vs. CC; OR = 1.31, 95 % CI 1.02–1.66 for Whites and OR = 1.22, 95 % CI 1.00–1.48 for African Americans), and (rs3218634 CG/CC vs. GG; OR = 1.29, 95 % CI 1.02–1.65 for Whites). These three SNPs are in high linkage disequilibrium in both races. Tumor subtype analysis showed the same SNPs to be associated with increased risk of Luminal breast cancer. SKAT analysis showed no significant combined SNP effects. These results suggest that variants in the POLQ gene may be associated with the risk of Luminal breast cancer. PMID:25417172

A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

PubMed

Chimusa, Emile R; Meintjies, Ayton; Tchanga, Milaine; Mulder, Nicola; Seoighe, Cathal; Seioghe, Cathal; Soodyall, Himla; Ramesar, Rajkumar

2015-03-01

We report a study of genome-wide, dense SNP (∼ 900K) and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

A Genomic Portrait of Haplotype Diversity and Signatures of Selection in Indigenous Southern African Populations

PubMed Central

Chimusa, Emile R.; Meintjies, Ayton; Tchanga, Milaine; Mulder, Nicola; Seoighe, Cathal; Soodyall, Himla; Ramesar, Rajkumar

2015-01-01

We report a study of genome-wide, dense SNP (∼900K) and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region. PMID:25811879

IL1B-CGTC haplotype is associated with colorectal cancer in admixed individuals with increased African ancestry

PubMed Central

Sanabria-Salas, María Carolina; Hernández-Suárez, Gustavo; Umaña-Pérez, Adriana; Rawlik, Konrad; Tenesa, Albert; Serrano-López, Martha Lucía; Sánchez de Gómez, Myriam; Rojas, Martha Patricia; Bravo, Luis Eduardo; Albis, Rosario; Plata, José Luis; Green, Heather; Borgovan, Theodor; Li, Li; Majumdar, Sumana; Garai, Jone; Lee, Edward; Ashktorab, Hassan; Brim, Hassan; Li, Li; Margolin, David; Fejerman, Laura; Zabaleta, Jovanny

2017-01-01

Single-nucleotide polymorphisms (SNPs) in cytokine genes can affect gene expression and thereby modulate inflammation and carcinogenesis. However, the data on the association between SNPs in the interleukin 1 beta gene (IL1B) and colorectal cancer (CRC) are conflicting. We found an association between a 4-SNP haplotype block of the IL1B (-3737C/-1464G/-511T/-31C) and CRC risk, and this association was exclusively observed in individuals with a higher proportion of African ancestry, such as individuals from the Coastal Colombian region (odds ratio, OR 2.06; 95% CI 1.31–3.25; p < 0.01). Moreover, a significant interaction between this CRC risk haplotype and local African ancestry dosage was identified in locus 2q14 (p = 0.03). We conclude that Colombian individuals with high African ancestry proportions at locus 2q14 harbour more IL1B-CGTC copies and are consequently at an increased risk of CRC. This haplotype has been previously found to increase the IL1B promoter activity and is the most frequent haplotype in African Americans. Despite of limitations in the number of samples and the lack of functional analysis to examine the effect of these haplotypes on CRC cell lines, our results suggest that inflammation and ethnicity play a major role in the modulation of CRC risk. PMID:28157220

Norrie disease gene sequence variants in an ethnically diverse population with retinopathy of prematurity.

PubMed

Hutcheson, Kelly A; Paluru, Prasuna C; Bernstein, Steven L; Koh, Jamie; Rappaport, Eric F; Leach, Richard A; Young, Terri L

2005-07-14

Retinopathy of prematurity (ROP) is a leading cause of visual loss in the pediatric population. Mutations in the Norrie disease gene (NDP) are associated with heritable retinal vascular disorders, and have been found in a small subset of patients with severe retinopathy of prematurity. Varying rates of progression to threshold disease in different races may have a genetic basis, as recent studies suggest that the incidence of NDP mutations may vary in different groups. African Americans, for example, are less likely to develop severe degrees of ROP. We screened a large cohort of ethnically diverse patients for mutations in the entire NDP. A total of 143 subjects of different ethnic backgrounds were enrolled in the study. Fifty-four patients had severe ROP (Stage 3 or worse). Of these, 38 were threshold in at least one eye (with a mean gestational age of 26.1 weeks and mean birth weight of 788.4 g). There were 36 patients with mild or no ROP, 31 parents with no history of retinal disease or prematurity, and 22 wild type (normal) controls. There were 70 African American subjects, 55 Caucasians, and 18 of other races. Severe ROP was noted in 29 African American subjects, 17 Caucasians, and 8 of other races. Seven polymerase chain reaction primer pairs spanning the NDP were optimized for denaturing high performance liquid chromatography and direct sequencing. Three primer pairs covered the coding region, and the remaining four spanned the 3' and 5' untranslated regions (UTR). Six of 54 (11%) infants with severe ROP had polymorphisms in the NDP. Five of the infants were African American, and one was Caucasian. Two parents were heterozygous for the same polymorphism as their child. One parent-child pair had a single base pair (bp) insertion in the 3' UTR region. Another parent-child pair had two mutations: a 14 bp deletion in the 5' UTR region of exon 1 and a single nucleotide polymorphism in the 5' UTR region of exon 2. No coding region sequence changes were found. No polymorphisms were observed in infants with mild or no ROP, or in the wild type controls. Of the six sequence alterations found, five were novel nucleotide changes: One in the 5' UTR region of exon 2, and four in the 3' UTR region of exon 3. The extent of NDP polymorphisms in this large, racially diverse group of infants is moderate. NDP polymorphisms may play a role in the pathogenesis of ROP, but do not appear to be a major causative factor.

VWF mutations and new sequence variations identified in healthy controls are more frequent in the African-American population.

PubMed

Bellissimo, Daniel B; Christopherson, Pamela A; Flood, Veronica H; Gill, Joan Cox; Friedman, Kenneth D; Haberichter, Sandra L; Shapiro, Amy D; Abshire, Thomas C; Leissinger, Cindy; Hoots, W Keith; Lusher, Jeanne M; Ragni, Margaret V; Montgomery, Robert R

2012-03-01

Diagnosis and classification of VWD is aided by molecular analysis of the VWF gene. Because VWF polymorphisms have not been fully characterized, we performed VWF laboratory testing and gene sequencing of 184 healthy controls with a negative bleeding history. The controls included 66 (35.9%) African Americans (AAs). We identified 21 new sequence variations, 13 (62%) of which occurred exclusively in AAs and 2 (G967D, T2666M) that were found in 10%-15% of the AA samples, suggesting they are polymorphisms. We identified 14 sequence variations reported previously as VWF mutations, the majority of which were type 1 mutations. These controls had VWF Ag levels within the normal range, suggesting that these sequence variations might not always reduce plasma VWF levels. Eleven mutations were found in AAs, and the frequency of M740I, H817Q, and R2185Q was 15%-18%. Ten AA controls had the 2N mutation H817Q; 1 was homozygous. The average factor VIII level in this group was 99 IU/dL, suggesting that this variation may confer little or no clinical symptoms. This study emphasizes the importance of sequencing healthy controls to understand ethnic-specific sequence variations so that asymptomatic sequence variations are not misidentified as mutations in other ethnic or racial groups.

Evolutionary Determinants of Morphological Polymorphism in Colonial Animals.

PubMed

Simpson, Carl; Jackson, Jeremy B C; Herrera-Cubilla, Amalia

2017-07-01

Colonial animals commonly exhibit morphologically polymorphic modular units that are phenotypically distinct and specialize in specific functional tasks. But how and why these polymorphic modules have evolved is poorly understood. Across colonial invertebrates, there is wide variation in the degree of polymorphism, from none in colonial ascidians to extreme polymorphism in siphonophores, such as the Portuguese man-of-war. Bryozoa are a phylum of exclusively colonial invertebrates that uniquely exhibit almost the entire range of polymorphism, from monomorphic species to others that rival siphonophores in their polymorphic complexity. Previous approaches to understanding the evolution of polymorphism have been based on analyses of (1) the functional role of polymorphs or (2) presumed evolutionary costs and benefits based on evolutionary theory that postulates polymorphism should be evolutionarily sustainable only in more stable environments because polymorphism commonly leads to the loss of feeding and sexual competence. Here we use bryozoans from opposite shores of the Isthmus of Panama to revisit the environmental hypothesis by comparison of faunas from distinct oceanographic provinces that differ greatly in environmental variability, and we then examine the correlations between the extent of polymorphism in relation to patterns of ecological succession and variation in life histories. We find no support for the environmental hypothesis. Distributions of the incidence of polymorphism in the oceanographically unstable Eastern Pacific are indistinguishable from those in the more stable Caribbean. In contrast, the temporal position of species in a successional sequence is collinear with the degree of polymorphism because species with fewer types of polymorphs are competitively replaced by species with higher numbers of polymorphs on the same substrata. Competitively dominant species also exhibit patterns of growth that increase their competitive ability. The association between degrees of polymorphism and variations in life histories is fundamental to understanding of the macroevolution of polymorphism.

Association of polymorphisms at the ADIPOR1 regulatory region with type 2 diabetes and body mass index in a Brazilian population with European or African ancestry.

PubMed

Yeh, E; Kimura, L; Errera, F I V; Angeli, C B; Mingroni-Netto, R C; Silva, M E R; Canani, L H S; Passos-Bueno, M R

2008-06-01

Association studies between ADIPOR1 genetic variants and predisposition to type 2 diabetes (DM2) have provided contradictory results. We determined if two single nucleotide polymorphisms (SNP c.-8503G>A and SNP c.10225C>G) in regulatory regions of ADIPOR1 in 567 Brazilian individuals of European (EA; N = 443) or African (AfA; N = 124) ancestry from rural (quilombo remnants; N = 439) and urban (N = 567) areas. We detected a significant effect of ethnicity on the distribution of the allelic frequencies of both SNPs in these populations (EA: -8503A = 0.27; AfA: -8503A = 0.16; P = 0.001 and EA: 10225G = 0.35; AfA: 10225G = 0.51; P < 0.001). Neither of the polymorphisms were associated with DM2 in the case-control study in EA (SNP c.-8503G>A: DM2 group -8503A = 0.26; control group -8503A = 0.30; P = 0.14/SNP 10225C>G: DM2 group 10225G = 0.37; control group 10225G = 0.32; P = 0.40) and AfA populations (SNP c.-8503G>A: DM2 group -8503A = 0.16; control group -8503A = 0.15; P = 0.34/SNP 10225C>G: DM2 group 10225G = 0.51; control group 10225G = 0.52; P = 0.50). Similarly, none of the polymorphisms were associated with metabolic/anthropometric risk factors for DM2 in any of the three populations, except for HDL cholesterol, which was significantly higher in AfA heterozygotes (GC = 53.75 +/- 17.26 mg/dL) than in homozygotes. We conclude that ADIPOR1 polymorphisms are unlikely to be major risk factors for DM2 or for metabolic/anthropometric measurements that represent risk factors for DM2 in populations of European and African ancestries.

Genetic Variation at Selected SNPs in the Leptin Gene and Association of Alleles with Markers of Kidney Disease in a Xhosa Population of South Africa

PubMed Central

Okpechi, Ikechi G.; Rayner, Brian L.; van der Merwe, Lize; Mayosi, Bongani M.; Adeyemo, Adebowale; Tiffin, Nicki; Ramesar, Rajkumar

2010-01-01

Background Chronic kidney disease (CKD) is a significant public health problem that leads to end-stage renal disease (ESRD) with as many as 2 million people predicted to need therapy worldwide by 2010. Obesity is a risk factor for CKD and leptin, the obesity hormone, correlates with body fat mass and markers of renal function. A number of clinical and experimental studies have suggested a link between serum leptin and kidney disease. We hypothesised that variants in the leptin gene (LEP) may be associated with markers of CKD in indigenous black Africans. Methodology/Principal Findings Black South Africans of Xhosa (distinct cultural Bantu-speaking population) descent were recruited for the study and four common polymorphisms of the LEP (rs7799039, rs791620, rs2167270 and STS-U43653 [ENSSNP5824596]) were analysed for genotype and haplotype association with urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), Serum creatinine (Scr) and serum leptin level. In one of the four single nucleotide polymorphisms (SNPs) we examined, an association with the renal phenotypes was observed. Hypertensive subjects with the T allele (CT genotype) of the ENSSNP5824596 SNP had a significantly higher eGFR (p = 0.0141), and significantly lower Scr (p = 0.0137). This was confirmed by haplotype analysis. Also, the haplotype GAAC had a modest effect on urine albumin-to-creatinine ratio in normotensive subjects (p = 0.0482). Conclusions/Significance These results suggest that genetic variations of the LEP may be associated with phenotypes that are markers of CKD in black Africans. PMID:20140086

The Geographic Distribution of Human Y Chromosome Variation

PubMed Central

Hammer, M. F.; Spurdle, A. B.; Karafet, T.; Bonner, M. R.; Wood, E. T.; Novelletto, A.; Malaspina, P.; Mitchell, R. J.; Horai, S.; Jenkins, T.; Zegura, S. L.

1997-01-01

We examined variation on the nonrecombining portion of the human Y chromosome to investigate human evolution during the last 200,000 years. The Y-specific polymorphic sites included the Y Alu insertional polymorphism or ``YAP'' element (DYS287), the poly(A) tail associated with the YAP element, three point mutations in close association with the YAP insertion site, an A-G polymorphic transition (DYS271), and a tetranucleotide microsatellite (DYS19). Global variation at the five bi-allelic sites (DYS271, DYS287, and the three point mutations) gave rise to five ``YAP haplotypes'' in 60 populations from Africa, Europe, Asia, Australasia, and the New World (n = 1500). Combining the multi-allelic variation at the microsatellite loci (poly(A) tail and DYS19) with the YAP haplotypes resulted in a total of 27 ``combination haplotypes''. All five of the YAP haplotypes and 21 of the 27 combination haplotypes were found in African populations, which had greater haplotype diversity than did populations from other geographical locations. Only subsets of the five YAP haplotypes were found outside of Africa. Patterns of observed variation were compatible with a variety of hypotheses, including multiple human migrations and range expansions. PMID:9055088

The Role of Dopamine in Anticipatory Pursuit Eye Movements: Insights from Genetic Polymorphisms in Healthy Adults

PubMed Central

Hennig, Jürgen

2016-01-01

Abstract There is a long history of eye movement research in patients with psychiatric diseases for which dysfunctions of neurotransmission are considered to be the major pathologic mechanism. However, neuromodulation of oculomotor control is still hardly understood. We aimed to investigate in particular the impact of dopamine on smooth pursuit eye movements. Systematic variability in dopaminergic transmission due to genetic polymorphisms in healthy subjects offers a noninvasive opportunity to determine functional associations. We measured smooth pursuit in 110 healthy subjects genotyped for two well-documented polymorphisms, the COMT Val158Met polymorphism and the SLC6A3 3′-UTR-VNTR polymorphism. Pursuit paradigms were chosen to particularly assess the ability of the pursuit system to initiate tracking when target motion onset is blanked, reflecting the impact of extraretinal signals. In contrast, when following a fully visible target sensory, retinal signals are available. Our results highlight the crucial functional role of dopamine for anticipatory, but not for sensory-driven, pursuit processes. We found the COMT Val158Met polymorphism specifically associated with anticipatory pursuit parameters, emphasizing the dominant impact of prefrontal dopamine activity on complex oculomotor control. In contrast, modulation of striatal dopamine activity by the SLC6A3 3′-UTR-VNTR polymorphism had no significant functional effect. Though often neglected so far, individual differences in healthy subjects provide a promising approach to uncovering functional mechanisms and can be used as a bridge to understanding deficits in patients. PMID:28101524

The Role of Dopamine in Anticipatory Pursuit Eye Movements: Insights from Genetic Polymorphisms in Healthy Adults.

PubMed

Billino, Jutta; Hennig, Jürgen; Gegenfurtner, Karl R

2016-01-01

There is a long history of eye movement research in patients with psychiatric diseases for which dysfunctions of neurotransmission are considered to be the major pathologic mechanism. However, neuromodulation of oculomotor control is still hardly understood. We aimed to investigate in particular the impact of dopamine on smooth pursuit eye movements. Systematic variability in dopaminergic transmission due to genetic polymorphisms in healthy subjects offers a noninvasive opportunity to determine functional associations. We measured smooth pursuit in 110 healthy subjects genotyped for two well-documented polymorphisms, the COMT Val 158 Met polymorphism and the SLC6A3 3'-UTR-VNTR polymorphism. Pursuit paradigms were chosen to particularly assess the ability of the pursuit system to initiate tracking when target motion onset is blanked, reflecting the impact of extraretinal signals. In contrast, when following a fully visible target sensory, retinal signals are available. Our results highlight the crucial functional role of dopamine for anticipatory, but not for sensory-driven, pursuit processes. We found the COMT Val 158 Met polymorphism specifically associated with anticipatory pursuit parameters, emphasizing the dominant impact of prefrontal dopamine activity on complex oculomotor control. In contrast, modulation of striatal dopamine activity by the SLC6A3 3'-UTR-VNTR polymorphism had no significant functional effect. Though often neglected so far, individual differences in healthy subjects provide a promising approach to uncovering functional mechanisms and can be used as a bridge to understanding deficits in patients.

Genome-wide patterns of genetic distances reveal candidate Loci contributing to human population-specific traits.

PubMed

de Magalhães, João Pedro; Matsuda, Alex

2012-03-01

Modern humans originated in Africa before migrating across the world with founder effects and adaptations to new environments contributing to their present phenotypic diversity. Determining the genetic basis of differences between populations may provide clues about our evolutionary history and may have clinical implications. Herein, we develop a method to detect genes and biological processes in which populations most differ by calculating the genetic distance between modern populations and a hypothetical ancestral population. We apply our method to large-scale single nucleotide polymorphism (SNP) data from human populations of African, European and Asian origin. As expected, ancestral alleles were more conserved in the African populations and we found evidence of high divergence in genes previously suggested as targets of selection related to skin pigmentation, immune response, senses and dietary adaptations. Our genome-wide scan also reveals novel candidates for contributing to population-specific traits. These include genes related to neuronal development and behavior that may have been influenced by cultural processes. Moreover, in the African populations, we found a high divergence in genes related to UV protection and to the male reproductive system. Taken together, these results confirm and expand previous findings, providing new clues about the evolution and genetics of human phenotypic diversity. © 2011 The Authors Annals of Human Genetics © 2011 Blackwell Publishing Ltd/University College London.

The genetics of East African populations: a Nilo-Saharan component in the African genetic landscape

PubMed Central

Dobon, Begoña; Hassan, Hisham Y.; Laayouni, Hafid; Luisi, Pierre; Ricaño-Ponce, Isis; Zhernakova, Alexandra; Wijmenga, Cisca; Tahir, Hanan; Comas, David; Netea, Mihai G.; Bertranpetit, Jaume

2015-01-01

East Africa is a strategic region to study human genetic diversity due to the presence of ethnically, linguistically, and geographically diverse populations. Here, we provide new insight into the genetic history of populations living in the Sudanese region of East Africa by analysing nine ethnic groups belonging to three African linguistic families: Niger-Kordofanian, Nilo-Saharan and Afro-Asiatic. A total of 500 individuals were genotyped for 200,000 single-nucleotide polymorphisms. Principal component analysis, clustering analysis using ADMIXTURE, FST statistics, and the three-population test were used to investigate the underlying genetic structure and ancestry of the different ethno-linguistic groups. Our analyses revealed a genetic component for Sudanese Nilo-Saharan speaking groups (Darfurians and part of Nuba populations) related to Nilotes of South Sudan, but not to other Sudanese populations or other sub-Saharan populations. Populations inhabiting the North of the region showed close genetic affinities with North Africa, with a component that could be remnant of North Africans before the migrations of Arabs from Arabia. In addition, we found very low genetic distances between populations in genes important for anti-malarial and anti-bacterial host defence, suggesting similar selective pressures on these genes and stressing the importance of considering functional pathways to understand the evolutionary history of populations. PMID:26017457

Prolactin and Dehydroepiandrosterone Levels in Women with Systemic Lupus Erythematosus: The Role of the Extrapituitary Prolactin Promoter Polymorphism at -1149G/T.

PubMed

Treadwell, Edward L; Wiley, Kenneth; Word, Beverly; Melchior, William; Tolleson, William H; Gopee, Neera; Hammons, George; Lyn-Cook, Beverly D

2015-01-01

Systemic lupus erythematosus (SLE) has shown an association with high levels of prolactin, low levels of dehydroepiandrosterone (DHEA), and induction of inflammatory cytokines in the serum of patients with the disease. This preliminary study examined the relevance of a -1149G/T functional single-nucleotide polymorphism (SNP) (rs1341239) in the promoter of the extrapituitary prolactin gene in a cohort of African American and European American women with lupus. Examination of this SNP revealed that the -1149TT genotype was correlated with higher levels of prolactin in serum and prolactin gene expression (p = 0.0001) in peripheral blood mononuclear cells (PBMCs). Lower levels of DHEA in serum were demonstrated in lupus patients (p = 0.001); those with the -1149TT genotype had the lowest levels of DHEA. Furthermore, a small subset of women who were on DHEA therapy and had a TT genotype showed a significant decrease in prolactin gene expression and lower disease activity scores (SLEDAI). Lupus patients, particularly African Americans, had significantly higher levels of IL-6 (p = 0.0001) and TNF-α (p = 0.042). This study suggests that the -1149TT genotype may be a risk factor for lupus and may predict who could possibly benefit from DHEA therapy; therefore, these results should be validated in a larger cohort with all ethnic groups.

D4 dopamine-receptor (DRD4) alleles and novelty seeking in substance-dependent, personality-disorder, and control subjects.

PubMed Central

Gelernter, J; Kranzler, H; Coccaro, E; Siever, L; New, A; Mulgrew, C L

1997-01-01

Two reports have been published suggesting an association between the personality trait of novelty seeking and the DRD4*7R allele at the D4 dopamine-receptor locus (with heterozygotes or homozygotes for DRD4*7R having higher novelty seeking). We studied novelty seeking and four coding-sequence polymorphisms affecting protein structure in the D4 dopamine-receptor gene (DRD4) in a sample of 341 American subjects, of whom 224 are of primarily European ancestry and 117 are of primarily African ancestry. These subjects had diagnoses of substance dependence or personality disorder (PD) or were screened to exclude major psychiatric diagnosis. We found that, although the substance-dependent subjects had significantly higher novelty seeking than the control and PD subjects, they did not differ in DRD4*7R allele frequency. There was no association between any DRD4 polymorphism and novelty seeking in any population or diagnostic group, except for a significant association between the DRD4*7R allele and lower novelty seeking among European American females and African American substance abusers. The novelty seeking of subjects heterozygous for a null mutation did not differ from that of subjects with two functional alleles. We conclude that the most likely explanation of these results is that the DRD4 VNTR does not influence directly the trait of novelty seeking, in these samples. PMID:9345090

Phylogenetic relationships among East African haplochromine fish as revealed by short interspersed elements (SINEs).

PubMed

Terai, Yohey; Takezaki, Naoko; Mayer, Werner E; Tichy, Herbert; Takahata, Naoyuki; Klein, Jan; Okada, Norihiro

2004-01-01

Genomic DNA libraries were prepared from two endemic species of Lake Victoria haplochromine (cichlid) fish and used to isolate and characterize a set of short interspersed elements (SINEs). The distribution and sequences of the SINEs were used to infer phylogenetic relationships among East African haplochromines. The SINE-based classification divides the fish into four groups, which, in order of their divergence from a stem lineage, are the endemic Lake Tanganyika flock (group 1); fish of the nonendemic, monotypic, widely distributed genus Astatoreochromis (group 2); the endemic Lake Malawi flock (group 3); and group 4, which contains fish from widely dispersed East African localities including Lakes Victoria, Edward, George, Albert, and Rukwa, as well as many rivers. The group 4 haplochromines are characterized by a subset of polymorphic SINEs, each of which is present in some individuals and absent in others of the same population at a given locality, the same morphologically defined species, and the same mtDNA-defined haplogroup. SINE-defined group 4 contains six of the seven previously described mtDNA haplogroups. One of the polymorphic SINEs appears to be fixed in the endemic Lake Victoria flock; four others display the presence-or-absence polymorphism within the species of this flock. These findings have implications for the origin of Lake Victoria cichlids and for their founding population sizes.

Worldwide Distribution of Four SNPs in X‐Ray and Repair and Cross‐Complementing Group 1 (XRCC1)

PubMed Central

Takeshita, Haruo; Yasuda, Toshihiro; Kimura‐Kataoka, Kaori

2014-01-01

Abstract Purpose X‐ray repair cross‐complementing group 1 (XRCC1) repairs single‐strand breaks in DNA. Several reports have shown the association of single nucleotide polymorphisms (SNPs) (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 to diseases. Limited population data are available regarding SNPs in XRCC1, especially in African populations. In this study, genotype distributions of four SNPs in worldwide populations were examined and compared with those reported previously. Materials and Methods Four SNPs (Arg194Trp, Pro206Pro, Arg280His, Arg399Gln) in XRCC1 from genomic DNA samples of 10 populations were evaluated by using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results The frequency of the minor allele corresponding to the Trp allele of XRCC1Arg194Trp was higher in Asian populations than in African and Caucasian populations. As for XRCC1Pro206Pro, Africans showed higher minor allele frequencies than did Asian populations, except for Tamils and Sinhalese. XRCC1 Arg280His frequencies were similar among Africans and Caucasians but differed among Asian populations. Similarly, lower mutant XRCC1 Arg399Gln frequencies were observed in Africans. Conclusions This study is the first to show the existence of a certain genetic heterogeneity in the worldwide distribution of four SNPs in XRCC1. PMID:25387884

Single nucleotide polymorphism-specific regulation of matrix metalloproteinase-9 by multiple miRNAs targeting the coding exon

PubMed Central

Duellman, Tyler; Warren, Christopher; Yang, Jay

2014-01-01

Microribonucleic acids (miRNAs) work with exquisite specificity and are able to distinguish a target from a non-target based on a single nucleotide mismatch in the core nucleotide domain. We questioned whether miRNA regulation of gene expression could occur in a single nucleotide polymorphism (SNP)-specific manner, manifesting as a post-transcriptional control of expression of genetic polymorphisms. In our recent study of the functional consequences of matrix metalloproteinase (MMP)-9 SNPs, we discovered that expression of a coding exon SNP in the pro-domain of the protein resulted in a profound decrease in the secreted protein. This missense SNP results in the N38S amino acid change and a loss of an N-glycosylation site. A systematic study demonstrated that the loss of secreted protein was due not to the loss of an N-glycosylation site, but rather an SNP-specific targeting by miR-671-3p and miR-657. Bioinformatics analysis identified 41 SNP-specific miRNA targeting MMP-9 SNPs, mostly in the coding exon and an extension of the analysis to chromosome 20, where the MMP-9 gene is located, suggesting that SNP-specific miRNAs targeting the coding exon are prevalent. This selective post-transcriptional regulation of a target messenger RNA harboring genetic polymorphisms by miRNAs offers an SNP-dependent post-transcriptional regulatory mechanism, allowing for polymorphic-specific differential gene regulation. PMID:24627221

Genetic risk factors for nonsyndromic cleft lip with or without cleft palate in a Brazilian population with high African ancestry.

PubMed

do Rego Borges, Andrea; Sá, Jamile; Hoshi, Ryuichi; Viena, Camila Sane; Mariano, Lorena C; de Castro Veiga, Patricia; Medrado, Alena Peixoto; Machado, Renato Assis; de Aquino, Sibele Nascimento; Messetti, Ana Camila; Spritz, Richard A; Coletta, Ricardo D; Reis, Silvia R A

2015-10-01

Nonsyndromic cleft lip with or without cleft palate (NSCL ± P) is the most common orofacial birth defect, exhibiting variable prevalence around the world, often attributed to ethnic and environmental differences. Linkage analyses and genome-wide association studies have identified several genomic susceptibility regions for NSCL ± P, mostly in European-derived or Asian populations. Genetic predisposition to NSCL ± P is ethnicity-dependent, and the genetic basis of susceptibility to NSCL ± P likely varies among populations. The population of Brazil is highly admixed, with highly variable ancestry; thus, the genetic determinants of NSCL ± P susceptibility may be quite different. This study tested association of 8 single-nucleotide polymorphisms (SNPs), previously identified by genome-wide studies in other populations, with NSCL ± P in a Brazilian population with high African ancestry. SNPs rs560426, rs642961, rs1530300, rs987525, rs3758249, rs7078160, rs17085106, and rs13041247 were genotyped in 293 Brazilian patients with NSCL ± P and 352 unaffected Brazilian controls. Each sample was also genotyped for 40 biallelic short insertion/deletion polymorphic markers to characterize genetic ancestry. The average African ancestry background was 31.1% for the NSCL ± P group and 36.7% for the control group. After adjustment for ancestry and multiple testing, the minor alleles of rs3758249 (OR: 1.58, 95% CI: 1.25-2.01, P = 0.0001) and rs7078160 (OR: 1.59, 95% CI: 1.21-2.07, P = 0.0002) were significantly associated with risk of NSCL ± P. Polymorphisms located in IRF6 (rs642961) and 8q24 (rs1530300 and rs987525) showed marginal associations in this Brazilian population with high African ancestry. These results indicate that rs3758249 at 9q22 and rs7078160 at 10q25.3 represent risk loci for NSCL ± P in the Brazilian population with high African ancestry. © 2015 Wiley Periodicals, Inc.

Vitamin D Receptor ApaI (rs7975232) Polymorphism Confers Decreased Risk of Pulmonary Tuberculosis in Overall and African Population, but not in Asians: Evidence from a Meta-analysis.

PubMed

Areeshi, Mohammed Y; Mandal, Raju K; Wahid, Mohd; Dar, Sajad A; Jawed, Arshad; Lohani, Mohtashim; Abdallah, Amir Mahgoub Awadelkareem; Khan, Saif; Panda, Aditya K; Mishra, B N; Haque, Shafiul

2017-09-01

The involvement of the VDR ApaI gene polymorphism in the development of pulmonary tuberculosis (PTB) has been reported by numerous published studies and yielded inconsistent results. The present meta-analysis evaluated the association of VDR ApaI polymorphism and risk of PTB occurrence. PubMed (Medline), EMBASE and Google Scholar web-databases were searched and a meta-analysis was performed by calculating the pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). This meta-analysis included a total of 14 eligible studies comprising of 1958 confirmed PTB cases and 2938 controls. We observed decreased risk of PTB in allelic (a vs. A: p =0.003; OR=0.873, 95% CI=0.798 to 0.955), homozygous (aa vs. AA: p =0.006; OR=0.761, 95% CI=0.626 to 0.924), dominant (aa+Aa vs. AA: p =0.039; OR=0.874, 95% CI=0.769 to 0.993) and recessive (aa vs. AA+Aa: p =0.025; OR=0.819, 95% CI=0.688 to 0.975) genetic models. During subgroup analysis, allele (a vs. A: p =0.005; OR=0.846, 95% CI=0.753 to 0.951), homozygous (aa vs. AA: p =0.002; OR=0.662, 95% CI=0.513 to 0.854) and recessive genetic models (aa vs. AA+Aa: p=0.003; OR=0.709, 95% CI=0.566 to 0.889) demonstrated decreased PTB risk in African population. However, no significant association was observed in Asian population. In conclusion, VDR ApaI polymorphism is significantly associated with decreased risk of PTB for in overall and African population, but not in Asians. © 2017 by the Association of Clinical Scientists, Inc.

Pharmacogenomics of warfarin in populations of African descent.

PubMed

Suarez-Kurtz, Guilherme; Botton, Mariana R

2013-02-01

Warfarin is the most commonly prescribed oral anticoagulant worldwide despite its narrow therapeutic index and the notorious inter- and intra-individual variability in dose required for the target clinical effect. Pharmacogenetic polymorphisms are major determinants of warfarin pharmacokinetic and dynamics and included in several warfarin dosing algorithms. This review focuses on warfarin pharmacogenomics in sub-Saharan peoples, African Americans and admixed Brazilians. These 'Black' populations differ in several aspects, notably their extent of recent admixture with Europeans, a factor which impacts on the frequency distribution of pharmacogenomic polymorphisms relevant to warfarin dose requirement for the target clinical effect. Whereas a small number of polymorphisms in VKORC1 (3673G > A, rs9923231), CYP2C9 (alleles *2 and *3, rs1799853 and rs1057910, respectively) and arguably CYP4F2 (rs2108622), may capture most of the pharmacogenomic influence on warfarin dose variance in White populations, additional polymorphisms in these, and in other, genes (e.g. CALU rs339097) increase the predictive power of pharmacogenetic warfarin dosing algorithms in the Black populations examined. A personalized strategy for initiation of warfarin therapy, allowing for improved safety and cost-effectiveness for populations of African descent must take into account their pharmacogenomic diversity, as well as socio-economical, cultural and medical factors. Accounting for this heterogeneity in algorithms that are 'friendly' enough to be adopted by warfarin prescribers worldwide requires gathering information from trials at different population levels, but demands also a critical appraisal of racial/ethnic labels that are commonly used in the clinical pharmacology literature but do not accurately reflect genetic ancestry and population diversity. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

Genetic variants associated with fetal hemoglobin levels show the diverse ethnic origin in Colombian patients with sickle cell anemia.

PubMed

Fong, Cristian; Menzel, Stephan; Lizarralde, María Alejandra; Barreto, Guillermo

2015-01-01

Fetal hemoglobin is an important factor in modulating the severity of sickle cell anemia. Its level in peripheral blood underlies strong genetic determination. Associated loci with increased levels of fetal hemoglobin display population-specific allele frequencies. We investigated the presence and effect of known common genetic variants promoting fetal hemoglobin persistence (rs11886868, rs9399137, rs4895441, and rs7482144) in 60 Colombian patients with sickle cell anemia. Four single nucleotide polymorphisms (SNP) were genotyped by restriction fragment length polymorphisms (RFLP) and the use of the TaqMan procedure. Fetal hemoglobin (HbF) from these patients was quantified using the oxyhemoglobin alkaline denaturation technique. Genotype frequencies were compared with frequencies reported in global reference populations. We detected genetic variants in the four SNPs, reported to be associated with higher HbF levels for all four SNPs in the Colombian patients. Genetic association between SNPs and HbF levels did not reach statistical significance. The frequency of these variants reflected the specific ethnic make-up of our patient population: A high prevalence of rs7482144-'A' reflects the West-African origin of the sickle cell mutation, while high frequencies of rs4895441-'G' and rs11886868-'C' point to a significant influence of an Amerindian ethnic background in the Colombian sickle cell disease population. These results showed that in the sickle cell disease population in Colombia there is not a unique genetic background, but two (African and Amerindian). This unique genetic situation will provide opportunities for a further study of these loci, such as fine-mapping and molecular-biological investigation. Colombian patients are expected to yield a distinctive insight into the effect of modifier loci in sickle cell disease.

Resequencing and Analysis of Variation in the TCF7L2 Gene in African Americans Suggests That SNP rs7903146 Is the Causal Diabetes Susceptibility Variant

PubMed Central

Palmer, Nicholette D.; Hester, Jessica M.; An, S. Sandy; Adeyemo, Adebowale; Rotimi, Charles; Langefeld, Carl D.; Freedman, Barry I.; Ng, Maggie C.Y.; Bowden, Donald W.

2011-01-01

OBJECTIVE Variation in the transcription factor 7-like 2 (TCF7L2) locus is associated with type 2 diabetes across multiple ethnicities. The aim of this study was to elucidate which variant in TCF7L2 confers diabetes susceptibility in African Americans. RESEARCH DESIGN AND METHODS Through the evaluation of tagging single nucleotide polymorphisms (SNPs), type 2 diabetes susceptibility was limited to a 4.3-kb interval, which contains the YRI (African) linkage disequilibrium (LD) block containing rs7903146. To better define the relationship between type 2 diabetes risk and genetic variation we resequenced this 4.3-kb region in 96 African American DNAs. Thirty-three novel and 13 known SNPs were identified: 20 with minor allele frequencies (MAF) >0.05 and 12 with MAF >0.10. These polymorphisms and the previously identified DG10S478 microsatellite were evaluated in African American type 2 diabetic cases (n = 1,033) and controls (n = 1,106). RESULTS Variants identified from direct sequencing and databases were genotyped or imputed. Fifteen SNPs showed association with type 2 diabetes (P < 0.05) with rs7903146 being the most significant (P = 6.32 × 10−6). Results of imputation, haplotype, and conditional analysis of SNPs were consistent with rs7903146 being the trait-defining SNP. Analysis of the DG10S478 microsatellite, which is outside the 4.3-kb LD block, revealed consistent association of risk allele 8 with type 2 diabetes (odds ratio [OR] = 1.33; P = 0.022) as reported in European populations; however, allele 16 (MAF = 0.016 cases and 0.032 controls) was strongly associated with reduced risk (OR = 0.39; P = 5.02 × 10−5) in contrast with previous studies. CONCLUSIONS In African Americans, these observations suggest that rs7903146 is the trait-defining polymorphism associated with type 2 diabetes risk. Collectively, these results support ethnic differences in type 2 diabetes associations. PMID:20980453

Variable continental distribution of polymorphisms in the coding regions of DNA-repair genes.

PubMed

Mathonnet, Géraldine; Labuda, Damian; Meloche, Caroline; Wambach, Tina; Krajinovic, Maja; Sinnett, Daniel

2003-01-01

DNA-repair pathways are critical for maintaining the integrity of the genetic material by protecting against mutations due to exposure-induced damages or replication errors. Polymorphisms in the corresponding genes may be relevant in genetic epidemiology by modifying individual cancer susceptibility or therapeutic response. We report data on the population distribution of potentially functional variants in XRCC1, APEX1, ERCC2, ERCC4, hMLH1, and hMSH3 genes among groups representing individuals of European, Middle Eastern, African, Southeast Asian and North American descent. The data indicate little interpopulation differentiation in some of these polymorphisms and typical FST values ranging from 10 to 17% at others. Low FST was observed in APEX1 and hMSH3 exon 23 in spite of their relatively high minor allele frequencies, which could suggest the effect of balancing selection. In XRCC1, hMSH3 exon 21 and hMLH1 Africa clusters either with Middle East and Europe or with Southeast Asia, which could be related to the demographic history of human populations, whereby human migrations and genetic drift rather than selection would account for the observed differences.

Epidermal Growth Factor (EGF) Receptor Intron 1 CA Repeat Polymorphisms in African-American and Caucasian Males: Influence on Prostate Cancer Risk or Disease Progression and Interaction with Androgen Receptor CAG Repeat Polymorphisms

DTIC Science & Technology

2003-09-01

Adipose Stromal Cells from Tumescent Liposuction Procedures. American Society for Dermatologic Surgery, $15,000 direct, 11/01/01 -10/31/02. 1999...stromal cells from tumescent liposuction procedures" ASDS Annual Meeting, Chicago, IL, November 1,2002."Adult Multipotent Stem Cells", Coriell

Association of TCF7L2 Gene Polymorphisms with Reduced Acute Insulin Response in Hispanic Americans

PubMed Central

Palmer, Nicholette D.; Lehtinen, Allison B.; Langefeld, Carl D.; Campbell, Joel K.; Haffner, Steven M.; Norris, Jill M.; Bergman, Richard N.; Goodarzi, Mark O.; Rotter, Jerome I.; Bowden, Donald W.

2008-01-01

Context: Genetic variation at the transcription factor 7-like 2 locus has been linked to type 2 diabetes in predominantly European-derived populations. The biological basis of these associations remains to be determined. Objective: The objective of this study was to evaluate previously associated variants for association with measures of glucose homeostasis in Hispanic-Americans and African-Americans and determine the biological mechanism(s) through which these variants exert their effect. Design: This study was the Insulin Resistance Atherosclerosis Family Study (IRAS-FS). Setting: The IRAS-FS is a community-based study of Hispanic-Americans (San Antonio, TX, and San Luis Valley, CO) and African-Americans (Los Angeles, CA). Participants: A total of 1040 Hispanic-American and 500 African-American individuals from the IRAS-FS formed the basis of this study. Main Outcomes Measures(s): The primary glucose homeostasis phenotypes of interest in this study were derived from the frequently sampled iv glucose tolerance test and include insulin sensitivity, acute insulin response, and disposition index. Results: In Hispanic-Americans, significant evidence of association was observed between single-nucleotide polymorphisms rs7903146 and rs112255372 with reduced insulin secretion as measured by acute insulin response and adjusted for the degree of insulin sensitivity (P = 0.032 and 0.036, respectively). Other quantitative measures, e.g. insulin sensitivity or disposition index, were not associated with the single nucleotide polymorphisms examined. In African-Americans there was no evidence of association observed. Conclusions: These results suggest that transcription factor 7-like 2 variants could play a role in the pathogenesis of type 2 diabetes in the Hispanic-American population through a mechanism involving insulin secretion. PMID:17971425

Association of TCF7L2 gene polymorphisms with reduced acute insulin response in Hispanic Americans.

PubMed

Palmer, Nicholette D; Lehtinen, Allison B; Langefeld, Carl D; Campbell, Joel K; Haffner, Steven M; Norris, Jill M; Bergman, Richard N; Goodarzi, Mark O; Rotter, Jerome I; Bowden, Donald W

2008-01-01

Genetic variation at the transcription factor 7-like 2 locus has been linked to type 2 diabetes in predominantly European-derived populations. The biological basis of these associations remains to be determined. The objective of this study was to evaluate previously associated variants for association with measures of glucose homeostasis in Hispanic-Americans and African-Americans and determine the biological mechanism(s) through which these variants exert their effect. This study was the Insulin Resistance Atherosclerosis Family Study (IRAS-FS). The IRAS-FS is a community-based study of Hispanic-Americans (San Antonio, TX, and San Luis Valley, CO) and African-Americans (Los Angeles, CA). A total of 1040 Hispanic-American and 500 African-American individuals from the IRAS-FS formed the basis of this study. MAIN OUTCOMES MEASURES(S): The primary glucose homeostasis phenotypes of interest in this study were derived from the frequently sampled iv glucose tolerance test and include insulin sensitivity, acute insulin response, and disposition index. In Hispanic-Americans, significant evidence of association was observed between single-nucleotide polymorphisms rs7903146 and rs112255372 with reduced insulin secretion as measured by acute insulin response and adjusted for the degree of insulin sensitivity (P = 0.032 and 0.036, respectively). Other quantitative measures, e.g. insulin sensitivity or disposition index, were not associated with the single nucleotide polymorphisms examined. In African-Americans there was no evidence of association observed. These results suggest that transcription factor 7-like 2 variants could play a role in the pathogenesis of type 2 diabetes in the Hispanic-American population through a mechanism involving insulin secretion.

Racial and sex differences in associations between activities of daily living and cognition in community-dwelling older adults.

PubMed

Garrett, Stephanie L; Sawyer, Patricia; Kennedy, Richard E; McGuire, Dawn; Simon, Roger P; Strothers, Harry S; Allman, Richard M

2013-12-01

To examine the association between function measured according to activities of daily living (ADLs), instrumental activ1ities of daily living (IADLs), and cognition assessed according to Mini-Mental State Examination (MMSE) scores of older African-American and non-Hispanic white community-dwelling men and women. Cross-sectional study assessing associations between self-reported ADL and IADL difficulty and MMSE scores for race- and sex-specific groups. Homes of community-dwelling older adults. A random sample of 974 African-American and non-Hispanic white Medicare beneficiaries aged 65 and older living in west-central Alabama and participating in the University of Alabama at Birmingham Study of Aging, excluding those with reported diagnoses of dementia or with missing data. Function, based on self-reported difficulty in performing ADLs and IADLs, and cognition, using the MMSE. Multivariable linear regression models were used to test the association between function and cognition in race- and sex-specific groups after adjusting for covariates. Mini-Mental State Examination scores were modestly correlated with ADL and IADL difficulty in all four race- and sex-specific groups, with Pearson correlation coefficients ranging from −0.189 for non-Hispanic white women to −0.429 for African-American men. Correlations between MMSE and ADL or IADL difficulty in any of the race- and sex-specific groups were no longer significant after controlling for sociodemographic factors and comorbidities. Mini-Mental State Examination was not significantly associated with functional difficulty in older African-American and non-Hispanic white men and women after adjusting for sociodemographic factors and comorbidities, suggesting a mediating role in the relationship between cognition and function. © 2013, Copyright the Authors Journal compilation © 2013, The American Geriatrics Society.

Genome-wide detection of natural selection in African Americans pre- and post-admixture

PubMed Central

Jin, Wenfei; Xu, Shuhua; Wang, Haifeng; Yu, Yongguo; Shen, Yiping; Wu, Bailin; Jin, Li

2012-01-01

It is particularly meaningful to investigate natural selection in African Americans (AfA) due to the high mortality their African ancestry has experienced in history. In this study, we examined 491,526 autosomal single nucleotide polymorphisms (SNPs) genotyped in 5210 individuals and conducted a genome-wide search for selection signals in 1890 AfA. Several genomic regions showing an excess of African or European ancestry, which were considered the footprints of selection since population admixture, were detected based on a commonly used approach. However, we also developed a new strategy to detect natural selection both pre- and post-admixture by reconstructing an ancestral African population (AAF) from inferred African components of ancestry in AfA and comparing it with indigenous African populations (IAF). Interestingly, many selection-candidate genes identified by the new approach were associated with AfA-specific high-risk diseases such as prostate cancer and hypertension, suggesting an important role these disease-related genes might have played in adapting to a new environment. CD36 and HBB, whose mutations confer a degree of protection against malaria, were also located in the highly differentiated regions between AAF and IAF. Further analysis showed that the frequencies of alleles protecting against malaria in AAF were lower than those in IAF, which is consistent with the relaxed selection pressure of malaria in the New World. There is no overlap between the top candidate genes detected by the two approaches, indicating the different environmental pressures AfA experienced pre- and post-population admixture. We suggest that the new approach is reasonably powerful and can also be applied to other admixed populations such as Latinos and Uyghurs. PMID:22128132

Single-Nucleotide Polymorphisms in LPA Explain Most of the Ancestry-Specific Variation in Lp(a) Levels in African Americans

PubMed Central

Lawson, Kim; Kao, W. H. Linda; Reich, David; Tandon, Arti; Akylbekova, Ermeg; Patterson, Nick; Mosley, Thomas H.; Boerwinkle, Eric; Taylor, Herman A.

2011-01-01

Lipoprotein(a) (Lp(a)) is an important causal cardiovascular risk factor, with serum Lp(a) levels predicting atherosclerotic heart disease and genetic determinants of Lp(a) levels showing association with myocardial infarction. Lp(a) levels vary widely between populations, with African-derived populations having nearly 2-fold higher Lp(a) levels than European Americans. We investigated the genetic basis of this difference in 4464 African Americans from the Jackson Heart Study (JHS) using a panel of up to 1447 ancestry informative markers, allowing us to accurately estimate the African ancestry proportion of each individual at each position in the genome. In an unbiased genome-wide admixture scan for frequency-differentiated genetic determinants of Lp(a) level, we found a convincing peak (LOD = 13.6) at 6q25.3, which spans the LPA locus. Dense fine-mapping of the LPA locus identified a number of strongly associated, common biallelic SNPs, a subset of which can account for up to 7% of the variation in Lp(a) level, as well as >70% of the African-European population differences in Lp(a) level. We replicated the association of the most strongly associated SNP, rs9457951 (p = 6×10−22, 27% change in Lp(a) per allele, ∼5% of Lp(a) variance explained in JHS), in 1,726 African Americans from the Dallas Heart Study and found an even stronger association after adjustment for the kringle(IV) repeat copy number. Despite the strong association with Lp(a) levels, we find no association of any LPA SNP with incident coronary heart disease in 3,225 African Americans from the Atherosclerosis Risk in Communities Study. PMID:21283670

Adenylyl Cyclase 9 Polymorphisms Reveal Potential Link to HDL Function and Cardiovascular Events in Multiple Pathologies: Potential Implications in Sickle Cell Disease.

PubMed

Niesor, Eric J; Benghozi, Renée; Amouyel, Philippe; Ferdinand, Keith C; Schwartz, Gregory G

2015-12-01

Adenylyl cyclase 9 (ADCY9) mediates β2-adrenoceptor (β2-AR) signalling. Both proteins are associated with caveolae, specialized cholesterol-rich membrane substructures. Apolipoprotein A1 (ApoA1), the major protein component of high-density lipoprotein (HDL), removes cholesterol from cell membrane and caveolae and may thereby influence β2-AR signalling, shown in vitro to be modulated by cholesterol. Patients with Sickle Cell Disease (SCD) typically have low HDL and ApoA1 levels. In patients, mainly of African origin, with SCD, β2-AR activation may trigger adhesion of red blood cells to endothelial cells, leading to vascular occlusive events. Moreover, ADCY9 polymorphism is associated with risk of stroke in SCD. In recent clinical trials, ADCY9 polymorphism was found to be a discriminant factor associated with the risk of cardiovascular (CV) events in Caucasian patients treated with the HDL-raising compound dalcetrapib. We hypothesize that these seemingly disparate observations share a common mechanism related to interaction of HDL/ApoA1 and ADCY9 on β2-AR signalling. This review also raises the importance of characterizing polymorphisms that determine the response to HDL-raising and -mimicking agents in the non-Caucasian population at high risk of CV diseases and suffering from SCD. This may facilitate personalized CV treatments.

Tissue-Specific and Genetic Regulation of Insulin Sensitivity-Associated Transcripts in African Americans

PubMed Central

Sharma, Neeraj K.; Sajuthi, Satria P.; Chou, Jeff W.; Calles-Escandon, Jorge; Demons, Jamehl; Rogers, Samantha; Ma, Lijun; Palmer, Nicholette D.; McWilliams, David R.; Beal, John; Comeau, Mary E.; Cherry, Kristina; Hawkins, Gregory A.; Menon, Lata; Kouba, Ethel; Davis, Donna; Burris, Marcie; Byerly, Sara J.; Easter, Linda; Bowden, Donald W.; Freedman, Barry I.; Langefeld, Carl D.

2016-01-01

Context: Compared with European Americans, African Americans (AAs) are more insulin resistant, have a higher insulin secretion response to glucose, and develop type 2 diabetes more often. Molecular processes and/or genetic variations contributing to altered glucose homeostasis in high-risk AAs remain uncharacterized. Objective: Adipose and muscle transcript expression profiling and genotyping were performed in 260 AAs to identify genetic regulatory mechanisms associated with insulin sensitivity (SI). We hypothesized that: 1) transcription profiles would reveal tissue-specific modulation of physiologic pathways with SI, and 2) a subset of SI-associated transcripts would be controlled by DNA sequence variants as expression quantitative traits, and these variants in turn would be associated with SI. Design and Settings: The cross-sectional research study was performed in a clinical research unit. Participants: Unrelated nondiabetic AAs were recruited for the study. Main Outcome Measures: SI was measured by frequently sampled iv glucose tolerance test. Results: The expression levels of 2212 transcripts in adipose and 145 transcripts in muscle were associated with SI. Genes involved in eIF2, eIF4-p70S6K, and mTOR signaling were modulated with SI in both tissues. Genes involved in leukocyte extravasation signaling showed adipose-specific regulation, and genes involved in oxidative phosphorylation had discordant regulation between tissues. Intersecting cis-expression quantitative trait loci results with data from transcript-SI association analysis identified cis-regulatory single nucleotide polymorphisms for 363 and 42 SI-associated transcripts in adipose and muscle, respectively. Cis-eSNPs for three SI-associated adipose transcripts, NINJ1, AGA, and CLEC10A were associated with SI. Abrogation of NINJ1 induction in THP1 macrophages modulated expression of genes in chemokine signaling, cell adhesion, and angiogenesis pathways. Conclusion: This study identified multiple pathways associated with SI; particularly discordant tissue-specific regulation of the oxidative phosphorylation pathway, and adipose-specific regulation of transcripts in the leukocyte extravasation signaling pathway that seem to be important in insulin resistance. Identification of single nucleotide polymorphisms associated with SI and with modulation of expression of SI-associated transcripts, including NINJ1, reveals novel genetic regulatory mechanisms of insulin resistance in AAs. PMID:26789776

The Impact of Ancestry and Common Genetic Variants on QT Interval in African Americans

PubMed Central

Smith, J. Gustav; Avery, Christy L.; Evans, Daniel S.; Nalls, Michael A.; Meng, Yan A.; Smith, Erin N.; Palmer, Cameron; Tanaka, Toshiko; Mehra, Reena; Butler, Anne M.; Young, Taylor; Buxbaum, Sarah G.; Kerr, Kathleen F.; Berenson, Gerald S.; Schnabel, Renate B.; Li, Guo; Ellinor, Patrick T.; Magnani, Jared W.; Chen, Wei; Bis, Joshua C.; Curb, J. David; Hsueh, Wen-Chi; Rotter, Jerome I.; Liu, Yongmei; Newman, Anne B.; Limacher, Marian C.; North, Kari E.; Reiner, Alexander P.; Quibrera, P. Miguel; Schork, Nicholas J.; Singleton, Andrew B.; Psaty, Bruce M.; Soliman, Elsayed Z.; Solomon, Allen J.; Srinivasan, Sathanur R.; Alonso, Alvaro; Wallace, Robert; Redline, Susan; Zhang, Zhu-Ming; Post, Wendy S.; Zonderman, Alan B.; Taylor, Herman A.; Murray, Sarah S.; Ferrucci, Luigi; Arking, Dan E.; Evans, Michele K.; Fox, Ervin R.; Sotoodehnia, Nona; Heckbert, Susan R.; Whitsel, Eric A.; Newton-Cheh, Christopher

2013-01-01

Background Ethnic differences in cardiac arrhythmia incidence have been reported, with a particularly high incidence of sudden cardiac death (SCD) and low incidence of atrial fibrillation in individuals of African ancestry. We tested the hypotheses that African ancestry and common genetic variants are associated with prolonged duration of cardiac repolarization, a central pathophysiological determinant of arrhythmia, as measured by the electrocardiographic QT interval. Methods and Results First, individual estimates of African and European ancestry were inferred from genome-wide single nucleotide polymorphism (SNP) data in seven population-based cohorts of African Americans (n=12 097) and regressed on measured QT interval from electrocardiograms. Second, imputation was performed for 2.8 million SNPs and a genome-wide association (GWA) study of QT interval performed in ten cohorts (n=13 105). There was no evidence of association between genetic ancestry and QT interval (p=0.94). Genome-wide significant associations (p<2.5×10−8) were identified with SNPs at two loci, upstream of the genes NOS1AP (rs12143842, p=2×10−15) and ATP1B1 (rs1320976, p=2×10−10). The most significant SNP in NOS1AP was the same as the strongest SNP previously associated with QT interval in individuals of European ancestry. Low p-values (p<10−5) were observed for SNPs at several other loci previously identified in GWA studies in individuals of European ancestry, including KCNQ1, KCNH2, LITAF and PLN. Conclusions We observed no difference in duration of cardiac repolarization with global genetic indices of African ancestry. In addition, our GWA study extends the association of polymorphisms at several loci associated with repolarization in individuals of European ancestry to include African Americans. PMID:23166209

Impact of ancestry and common genetic variants on QT interval in African Americans.

PubMed

Smith, J Gustav; Avery, Christy L; Evans, Daniel S; Nalls, Michael A; Meng, Yan A; Smith, Erin N; Palmer, Cameron; Tanaka, Toshiko; Mehra, Reena; Butler, Anne M; Young, Taylor; Buxbaum, Sarah G; Kerr, Kathleen F; Berenson, Gerald S; Schnabel, Renate B; Li, Guo; Ellinor, Patrick T; Magnani, Jared W; Chen, Wei; Bis, Joshua C; Curb, J David; Hsueh, Wen-Chi; Rotter, Jerome I; Liu, Yongmei; Newman, Anne B; Limacher, Marian C; North, Kari E; Reiner, Alexander P; Quibrera, P Miguel; Schork, Nicholas J; Singleton, Andrew B; Psaty, Bruce M; Soliman, Elsayed Z; Solomon, Allen J; Srinivasan, Sathanur R; Alonso, Alvaro; Wallace, Robert; Redline, Susan; Zhang, Zhu-Ming; Post, Wendy S; Zonderman, Alan B; Taylor, Herman A; Murray, Sarah S; Ferrucci, Luigi; Arking, Dan E; Evans, Michele K; Fox, Ervin R; Sotoodehnia, Nona; Heckbert, Susan R; Whitsel, Eric A; Newton-Cheh, Christopher

2012-12-01

Ethnic differences in cardiac arrhythmia incidence have been reported, with a particularly high incidence of sudden cardiac death and low incidence of atrial fibrillation in individuals of African ancestry. We tested the hypotheses that African ancestry and common genetic variants are associated with prolonged duration of cardiac repolarization, a central pathophysiological determinant of arrhythmia, as measured by the electrocardiographic QT interval. First, individual estimates of African and European ancestry were inferred from genome-wide single-nucleotide polymorphism (SNP) data in 7 population-based cohorts of African Americans (n=12,097) and regressed on measured QT interval from ECGs. Second, imputation was performed for 2.8 million SNPs, and a genome-wide association study of QT interval was performed in 10 cohorts (n=13,105). There was no evidence of association between genetic ancestry and QT interval (P=0.94). Genome-wide significant associations (P<2.5 × 10(-8)) were identified with SNPs at 2 loci, upstream of the genes NOS1AP (rs12143842, P=2 × 10(-15)) and ATP1B1 (rs1320976, P=2 × 10(-10)). The most significant SNP in NOS1AP was the same as the strongest SNP previously associated with QT interval in individuals of European ancestry. Low probability values (P<10(-5)) were observed for SNPs at several other loci previously identified in genome-wide association studies in individuals of European ancestry, including KCNQ1, KCNH2, LITAF, and PLN. We observed no difference in duration of cardiac repolarization with global genetic indices of African American ancestry. In addition, our genome-wide association study extends the association of polymorphisms at several loci associated with repolarization in individuals of European ancestry to include individuals of African ancestry.

Clinical and Genetic Modifiers of Long-term Survival in Heart Failure

PubMed Central

Cresci, Sharon; Kelly, Reagan J; Cappola, Thomas P; ScM; Diwan, Abhinav; Dries, Daniel; Kardia, Sharon LR; Dorn, Gerald W

2009-01-01

Objective To identify genetic modifiers of β-blocker (BB) response and long-term survival in heart failure (HF). Background Differences in BB treatment effect between Caucasians and African Americans with HF have been reported. Methods Prospective cohort study of 2,460 patients (711 African American; 1,749 Caucasian) enrolled between 1999 and 2007. 2039 (81.7%) were treated with BB. Each was genotyped for β1-adrenergic receptor (ADRB1) Arg389>Gly and G-protein receptor kinase 5 (GRK5) Gln41>Leu polymorphisms, which are more prevalent among African Americans than Caucasians. Primary endpoint was survival time from HF onset. Results There were 765 deaths during follow up (median 46 months). BB treatment increased survival in Caucasians (Log Rank P=0.00038) but not African Americans (Log Rank P=0.327). Among patients not taking BB, ADRB1 Gly389 was associated with decreased survival in Caucasians (HR = 1.98, 95% CI = 1.1 − 3.7, P = 0.03) while GRK5 Leu41 was associated with improved survival in African Americans (HR = 0.325, CI = 0.133 − 0.796, P = 0.01). ADRB1 Gly389 GRK5 Gln41Gln African Americans derived similar survival benefit from BB therapy (HR = 0.385 95% CI = 0.182 − 0.813, P = 0.012) as ADRB1 Gly389 GRK5 Gln41Gln Caucasians (HR = 0.529, 95% CI = 0.326 − 0.858, P=0.0098). Conclusions These data demonstrate that differences caused by β-adrenergic receptor signaling pathway gene polymorphisms, rather than race, are the major factors contributing to apparent differences in BB treatment effect between Caucasians and African Americans; proper evaluation of treatment response should account for genetic variance. PMID:19628119

Personality assessment and its association with genetic factors in captive Asian and African elephants.

PubMed

Yasui, Saki; Konno, Akitsugu; Tanaka, Masayuki; Idani, Gen'ichi; Ludwig, Arne; Lieckfeldt, Dietmar; Inoue-Murayama, Miho

2013-01-01

Elephants live in a complex society based on matrilineal groups. Management of captive elephants is difficult, partly because each elephant has a unique personality. For a better understanding of elephant well being in captivity, it would be helpful to systematically evaluate elephants' personalities and their underlying biological basis. We sent elephant' personality questionnaires to keepers of 75 elephants. We also used 196 elephant DNA samples to search for genetic polymorphisms in genes expressed in the brain that have been suggested to be related to personality traits. Three genes, androgen receptor (AR), fragile X related mental retardation protein interacting protein (NUFIP2), and acheate-scute homologs 1 (ASH1) contained polymorphic regions. We examined the association of personality with intraspecific genetic variation in 17 Asian and 28 African elephants. The results suggest that the ASH1 genotype was associated with neuroticism in Asian elephants. Subjects with short alleles had lower scores of neuroticism than those with long alleles. This is the first report of an association between a genetic polymorphism and personality in elephants. © 2012 Wiley Periodicals, Inc.

Parallel Geographic Variation in Drosophila melanogaster

PubMed Central

Reinhardt, Josie A.; Kolaczkowski, Bryan; Jones, Corbin D.; Begun, David J.; Kern, Andrew D.

2014-01-01

Drosophila melanogaster, an ancestrally African species, has recently spread throughout the world, associated with human activity. The species has served as the focus of many studies investigating local adaptation relating to latitudinal variation in non-African populations, especially those from the United States and Australia. These studies have documented the existence of shared, genetically determined phenotypic clines for several life history and morphological traits. However, there are no studies designed to formally address the degree of shared latitudinal differentiation at the genomic level. Here we present our comparative analysis of such differentiation. Not surprisingly, we find evidence of substantial, shared selection responses on the two continents, probably resulting from selection on standing ancestral variation. The polymorphic inversion In(3R)P has an important effect on this pattern, but considerable parallelism is also observed across the genome in regions not associated with inversion polymorphism. Interestingly, parallel latitudinal differentiation is observed even for variants that are not particularly strongly differentiated, which suggests that very large numbers of polymorphisms are targets of spatially varying selection in this species. PMID:24610860

Lung function and exhaled nitric oxide in healthy unsedated African infants

PubMed Central

Gray, Diane; Willemse, Lauren; Visagie, Ane; Smith, Emilee; Czövek, Dorottya; Sly, Peter D; Hantos, Zoltán; Hall, Graham L; Zar, Heather J

2015-01-01

Background and objective Population-appropriate lung function reference data are essential to accurately identify respiratory disease and measure response to interventions. There are currently no reference data in African infants. The aim was to describe normal lung function in healthy African infants. Methods Lung function was performed on healthy South African infants enrolled in a birth cohort study, the Drakenstein child health study. Infants were excluded if they were born preterm or had a history of neonatal respiratory distress or prior respiratory tract infection. Measurements, made during natural sleep, included the forced oscillation technique, tidal breathing, exhaled nitric oxide and multiple breath washout measures. Results Three hundred sixty-three infants were tested. Acceptable and repeatable measurements were obtained in 356 (98%) and 352 (97%) infants for tidal breathing analysis and exhaled nitric oxide outcomes, 345 (95%) infants for multiple breath washout and 293 of the 333 (88%) infants for the forced oscillation technique. Age, sex and weight-for-age z score were significantly associated with lung function measures. Conclusions This study provides reference data for unsedated infant lung function in African infants and highlights the importance of using population-specific data. PMID:26134556

Isolation and characterization of Y chromosome sequences from the African malaria mosquito Anopheles gambiae.

PubMed Central

Krzywinski, Jaroslaw; Nusskern, Deborah R; Kern, Marcia K; Besansky, Nora J

2004-01-01

The karyotype of the African malaria mosquito Anopheles gambiae contains two pairs of autosomes and a pair of sex chromosomes. The Y chromosome, constituting approximately 10% of the genome, remains virtually unexplored, despite the recent completion of the A. gambiae genome project. Here we report the identification and characterization of Y chromosome sequences of total length approaching 150 kb. We developed 11 Y-specific PCR markers that consistently yielded male-specific products in specimens from both laboratory colony and natural populations. The markers are characterized by low sequence polymorphism in samples collected across Africa and by presence in more than one copy on the Y. Screening of the A. gambiae BAC library using these markers allowed detection of 90 Y-linked BAC clones. Analysis of the BAC sequences and other Y-derived fragments showed massive accumulation of a few transposable elements. Nevertheless, more complex sequences are apparently present on the Y; these include portions of an approximately 48-kb-long unmapped AAAB01008227 scaffold from the whole genome shotgun assembly. Anopheles Y appears not to harbor any of the genes identified in Drosophila Y. However, experiments suggest that one of the ORFs from the AAAB01008227 scaffold represents a fragment of a gene with male-specific expression. PMID:15082548

Genotype imputation for African Americans using data from HapMap phase II versus 1000 genomes projects.

PubMed

Sung, Yun J; Gu, C Charles; Tiwari, Hemant K; Arnett, Donna K; Broeckel, Ulrich; Rao, Dabeeru C

2012-07-01

Genotype imputation provides imputation of untyped single nucleotide polymorphisms (SNPs) that are present on a reference panel such as those from the HapMap Project. It is popular for increasing statistical power and comparing results across studies using different platforms. Imputation for African American populations is challenging because their linkage disequilibrium blocks are shorter and also because no ideal reference panel is available due to admixture. In this paper, we evaluated three imputation strategies for African Americans. The intersection strategy used a combined panel consisting of SNPs polymorphic in both CEU and YRI. The union strategy used a panel consisting of SNPs polymorphic in either CEU or YRI. The merge strategy merged results from two separate imputations, one using CEU and the other using YRI. Because recent investigators are increasingly using the data from the 1000 Genomes (1KG) Project for genotype imputation, we evaluated both 1KG-based imputations and HapMap-based imputations. We used 23,707 SNPs from chromosomes 21 and 22 on Affymetrix SNP Array 6.0 genotyped for 1,075 HyperGEN African Americans. We found that 1KG-based imputations provided a substantially larger number of variants than HapMap-based imputations, about three times as many common variants and eight times as many rare and low-frequency variants. This higher yield is expected because the 1KG panel includes more SNPs. Accuracy rates using 1KG data were slightly lower than those using HapMap data before filtering, but slightly higher after filtering. The union strategy provided the highest imputation yield with next highest accuracy. The intersection strategy provided the lowest imputation yield but the highest accuracy. The merge strategy provided the lowest imputation accuracy. We observed that SNPs polymorphic only in CEU had much lower accuracy, reducing the accuracy of the union strategy. Our findings suggest that 1KG-based imputations can facilitate discovery of significant associations for SNPs across the whole MAF spectrum. Because the 1KG Project is still under way, we expect that later versions will provide better imputation performance. © 2012 Wiley Periodicals, Inc.

Ethnic differences in the +405 and -460 vascular endothelial growth factor polymorphisms and peripheral neuropathy in patients with diabetes residing in a North London, community in the United Kingdom.

PubMed

Zitouni, Karima; Tinworth, Lorna; Earle, Kenneth Anthony

2017-06-29

There are marked ethnic differences in the susceptibility to the long-term diabetic vascular complications including sensory neuropathy. The vascular endothelial growth factor (VEGF) +405 (C/G) and -460 (T/C) polymorphisms are associated with retinopathy and possibly with nephropathy, however no information is available on their relationship with peripheral neuropathy. Therefore, we examined the prevalence of these VEGF genotypes in a multi-ethnic cohort of patients with diabetes and their relationship with evident peripheral diabetic neuropathy. In the current investigation, we studied 313 patients with diabetes mellitus of African-Caribbean, Indo-Asian and Caucasian ethnic origin residing in an inner-city community in London, United Kingdom attending a single secondary care centre. Genotyping was performed for the VEGF +405 and VEGF -460 polymorphisms using a pyrosequencing technique. Forty-nine patients (15.6%) had clinical evidence of peripheral neuropathy. Compared to Caucasian patients, African-Caribbean and Indo-Asian patients had lower incidence of neuropathy (24.6%, 14.28%, 6.7%, respectively; P = 0.04). The frequency of the VEGF +405 GG genotype was more common in Indo-Asian patients compared to African-Caribbean and Caucasian patients (67.5%, 45.3%, 38.4%, respectively; p ≤ 0.02). The G allele was more common in patients with type 2 diabetes of Indo-Asian origin compared to African-Caribbean and Caucasian origin (p ≤ 0.02). There was no difference between the ethnic groups in VEGF -460 genotypes. The distributions of the VEGF +405 and VEGF -460 genotypes were similar between the diabetic patients with and without neuropathy. In this cohort of patients, VEGF +405 and VEGF -460 polymorphisms were not associated with evident diabetic peripheral neuropathy, however an association was found between VEGF +405 genotypes and Indo-Asian which might have relevance to their lower rates of ulceration and amputation. This finding highlights the need for further investigation of any possible relationship between VEGF genotype, circulating VEGF concentrations and differential vulnerability to peripheral neuropathy amongst diabetic patients of different ethnic backgrounds.

Frequency distribution of interleukin-10 haplotypes (-1082 A>G, -819 C>T, and -592 C>A) in a Mexican population.

PubMed

Vázquez-Villamar, M; Palafox-Sánchez, C A; Hernández-Bello, J; Muñoz-Valle, J F; Valle, Y; Cruz, A; Alatorre-Meza, A I; Oregon-Romero, E

2016-11-03

Interleukin 10 (IL-10) is an immunoregulatory cytokine with multiple roles in the immune system. Three single nucleotide polymorphisms at positions -1082 (A>G), -819 (C>T), and -592 (C>A) in the promoter region of the IL10 gene are believed to be associated with different inflammatory, infectious, and autoimmune diseases. These polymorphisms exhibit a strong linkage disequilibrium (LD) and form three principal haplotypes (GCC, ACC, and ATA). The GCC and ATA haplotypes have been associated with high and low levels of IL-10 production, respectively. The aim of this study was to establish the allele and haplotype frequencies of the IL10 polymorphisms in Mestizos from western Mexico. SNPs were analyzed in 340 healthy unrelated Mestizos from western Mexico by polymerase chain reaction-restriction fragment length polymorphism. The studied population presented significant differences, in the distribution of IL10 polymorphisms, from the Asian, African, and European populations. We also observed a strong LD within -1082 A>G, -819 C>T, and -592 C>A (100% pc = 7.735 x 10 -18 ). The haplotypes ACC (45.4%), ATA (22.0%), GTA (14.9%), and GCC (13.9%) were most frequently observed in this population. The haplotype frequencies, however, differed from those reported previously in Mestizos from central Mexico, Asians, Africans, and European Caucasians, suggesting a differential gene flow in the Mexican Mestizo population. This could account for the genetic variability between Mexicans and populations of other ethnicities. The study of these polymorphisms and their haplotypes could help in expanding our knowledge to design future disease-risk studies on the western Mexican population.

The origins of the Lemba "Black Jews" of southern Africa: evidence from p12F2 and other Y-chromosome markers.

PubMed Central

Spurdle, A. B.; Jenkins, T.

1996-01-01

The Lemba are a southern African Bantu-speaking population claiming Jewish ancestry. Allele frequencies at four different Y-specific polymorphic loci, as well as extended-haplotype frequencies that included data from several loci, were analyzed in an attempt to establish the genetic affinities and origins of the Lemba. The results suggest that > or = 50% of the Lemba Y chromosomes are Semitic in origin, approximately 40% are Negroid, and the ancestry of the remainder cannot be resolved. These Y-specific genetic findings are consistent with Lemba oral tradition, and analysis of the history of Jewish people and their association with Africa indicates that the historical facts are not incompatible with theories concerning the origin of the Lemba. PMID:8900243

Genes determining the severity of cerebral palsy: the role of single nucleotide polymorphisms on the amount and structure of apolipoprotein E

PubMed Central

Lien, Espen; Andersen, Guro; Bao, Yongde; Gordish-Dressman, Heather; Skranes, Jon S.; Blackman, James A.; Vik, Torstein

2015-01-01

Aim ApolipoproteinE (apoE) influences repair and other processes in the brain and the apoE4 variant is a risk factor for Alzheimer's disease and for prolonged recovery following traumatic brain injury. We previously reported that specific single nucleotide polymorphisms in the APOE or TOMM40 genes affecting the structure and production of apoE were associated with epilepsy, more impaired hand function and gastrostomy tube feeding in children with cerebral palsy (CP). This study explored how various combinations of the same polymorphisms may affect these clinical manifestations. Methods Successful DNA analyses of APOE and TOMM40 were carried out on 227 children. The CP Register of Norway provided details of gross and fine motor function, epilepsy and gastrostomy tube feeding. Possible associations between these clinical manifestations and various combinations of the APOEε2, ε3 or ε4 alleles and of the rs59007384 polymorphism in the TOMM40 gene were explored. Results Epilepsy, impaired fine motor function and gastrostomy tube feeding were less common in children carrying the combination of rs59007384 GG and APOEε2 or ε3 than in children with other combinations. Conclusion Our findings suggest that specific combinations of genes influence the structure and production of apoE differently and affect the clinical manifestations of CP. PMID:25703783

Inference of Evolutionary Forces Acting on Human Biological Pathways

PubMed Central

Daub, Josephine T.; Dupanloup, Isabelle; Robinson-Rechavi, Marc; Excoffier, Laurent

2015-01-01

Because natural selection is likely to act on multiple genes underlying a given phenotypic trait, we study here the potential effect of ongoing and past selection on the genetic diversity of human biological pathways. We first show that genes included in gene sets are generally under stronger selective constraints than other genes and that their evolutionary response is correlated. We then introduce a new procedure to detect selection at the pathway level based on a decomposition of the classical McDonald–Kreitman test extended to multiple genes. This new test, called 2DNS, detects outlier gene sets and takes into account past demographic effects and evolutionary constraints specific to gene sets. Selective forces acting on gene sets can be easily identified by a mere visual inspection of the position of the gene sets relative to their two-dimensional null distribution. We thus find several outlier gene sets that show signals of positive, balancing, or purifying selection but also others showing an ancient relaxation of selective constraints. The principle of the 2DNS test can also be applied to other genomic contrasts. For instance, the comparison of patterns of polymorphisms private to African and non-African populations reveals that most pathways show a higher proportion of nonsynonymous mutations in non-Africans than in Africans, potentially due to different demographic histories and selective pressures. PMID:25971280

A novel FY allele in Brazilians.

PubMed

Castilho, L; Rios, M; Pellegrino, J; Saad, S T O; Costa, F F; Reid, M E

2004-10-01

The GATA box single nucleotide polymorphism (SNP) at position -33 (T>C) in Blacks silences the expression of FY*B in erythrocytes, and the substitution 265 C>T, together with 298 G>A, weakens the Fy(b) antigen (Fy(x)). Individuals with these phenotypes/genotypes who receive Fy(b+) blood are unlikely to be alloimmunized to Fy(b) because, in the presence of 265 T, the Fy(b) antigen is expressed, and in the case of -33 C, other tissues express Duffy protein and probably the Fy(b) antigen. We studied samples from 361 blood donors (182 of African ancestry and 179 of Caucasian ancestry) by haemagglutination and polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP). Forty Caucasian and 130 donors of African ancestry were serologically Fy(b-); among these, the majority of the donors of African ancestry had FY*B with the GATA SNP, while the majority of Caucasians typing Fy(b-) had FY*B with 265 T/298 A SNPs. Six of the Fy(b-) donors (three Africans and three Caucasians) had both GATA and 265/298 SNPs, and six donors of Caucasian ancestry apparently had a GATA SNP. Samples from two donors - one African and one Caucasian with an unusual MspA1I-RFLP pattern - were sequenced and found to have a novel SNP (145 G>T) co-existent with 265 C>T and 298 G>A SNPs. These findings highlight the importance of establishing the incidence and nature of molecular events that impact on Duffy expression in different populations.

Association of ferroportin Q248H polymorphism with elevated levels of serum ferritin in African-Americans in the Hemochromatosis and Iron Overload Screening (HEIRS) Study

PubMed Central

Rivers, Charles A.; Barton, James C.; Gordeuk, Victor R.; Acton, Ronald T.; Speechley, Mark R.; Snively, Beverly M.; Leiendecker-Foster, Catherine; Press, Richard D.; Adams, Paul C.; McLaren, Gordon D.; Dawkins, Fitzroy W.; McLaren, Christine E.; Reboussin, David M.

2007-01-01

The ferroportin (FPN1) Q248H polymorphism has been associated with increased serum ferritin (SF) levels in sub-Saharan Africans and in African Americans (AA). AA participants of the HEIRS Study who did not have HFE C282Y or H63D who had elevated initial screening SF (≥300 μg/L in men and ≥200 μg/L in women) (defined as cases) were frequency-matched to AA participants with normal SF (defined as controls) to investigate the association of the Q248H with elevated SF. 10.4% of cases and 6.7% of controls were Q248H heterozygotes (P = 0.257). Q248H homozygosity was observed in 0.5% of the cases and none of the controls. The frequency of Q248H was higher among men with elevated SF than among control men (P = 0.047); corresponding differences were not observed among women. This appeared to be unrelated to self-reports of a previous diagnosis of liver disease. Men with elevated SF were three times more likely than women with elevated SF to have Q248H (P = 0.012). There were no significant differences in Q248H frequencies in men and women control participants. We conclude that the frequency of the FPN1 Q248H polymorphism is greater in AA men with elevated SF than in those with normal SF. PMID:17276706

Inversion Monophyly in African Anopheline Malaria Vectors

PubMed Central

Garcia, B. A.; Caccone, A.; Mathiopoulos, K. D.; Powell, J. R.

1996-01-01

The African Anopheles gambiae complex of six sibling species has many polymorphic and fixed paracentric inversions detectable in polytene chromosomes. These have been used to infer phylogenetic relationships as classically done with Drosophila. Two species, A. gambiae and A. merus, were thought to be sister taxa based on a shared X inversion designated X(ag). Recent DNA data have conflicted with this phylogenetic inference as they have supported a sister taxa relationship of A. gambiae and A. arabiensis. A possible explanation is that the X(ag) is not monophyletic. Here we present data from a gene (soluble guanylate cyclase) within the X(ag) that strongly supports the monophyly of the X(ag). We conjecture that introgression may be occurring between the widely sympatric species A. gambiae and A. arabiensis and that the previous DNA phylogenies have been detecting the introgression. Evidently, introgression is not uniform across the genome, and species-specific regions, like the X-chromosome inversions, do not introgress probably due to selective elimination in hybrids and backcrosses. PMID:8807303

Prevalence of Hb S (HHB: c.20A > T) in a Honduran population of African descent.

PubMed

Erazo, Brian M; Ramírez, Gilberto A; Cerrato, Linda E; Pinto, Luis J; Castro, Edder J; Yanez, Néstor J; Montoya, Brayan; Fontecha, Gustavo A

2015-01-01

Sickle cell disease is the most common hemoglobinopathy worldwide, particularly in Africa and among people of African descent. Serious clinical consequences characterize the homozygous condition. To determine the prevalence of Hb S (HBB: c.20A > T) and anemia in a community of people of African descent from Honduras, 202 individuals were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The high prevalence found indicates that it is necessary to implement a program to prevent the consequences of this disease in vulnerable populations of Honduras.

Using Polymorphisms in FKBP5 to Define Biologically Distinct Subtypes of Posttraumatic Stress Disorder

PubMed Central

Mehta, Divya; Gonik, Mariya; Klengel, Torsten; Rex-Haffner, Monika; Menke, Andreas; Rubel, Jennifer; Mercer, Kristina B.; Pütz, Benno; Bradley, Bekh; Holsboer, Florian; Ressler, Kerry J.; Müller-Myhsok, Bertram; Binder, Elisabeth B.

2013-01-01

Context Polymorphisms in the gene encoding the glucocorticoid receptor (GR) regulating co-chaperone FKBP5 have been shown to alter GR sensitivity and are associated with an increased risk to develop posttraumatic stress disorder (PTSD). Objective To investigate interactions of the FKBP5 single-nucleotide polymorphism rs9296158 and PTSD symptoms on baseline cortisol level, low-dose dexamethasone suppression, and whole-blood gene expression. Design Association of FKBP5 genotypes and PTSD symptoms with endocrine measures and genome-wide expression profiles. Setting Waiting rooms of general medical and gynecological clinics of an urban hospital at Emory University. Participants The 211 participants were primarily African American (90.05%) and of low socioeconomic status and had high rates of trauma and PTSD. Main Outcome Measures Baseline and post–dexamethasone suppression cortisol measures and gene expression levels. Results In our endocrine study, we found that only risk allele A carriers of rs9296158 showed GR supersensitivity with PTSD; in contrast, baseline cortisol levels were decreased in PTSD only in patients with the GG genotype. Expression of 183 transcripts was significantly correlated with PTSD symptoms after multiple testing corrections. When adding FKBP5 genotype and its interaction with PTSD symptoms, expression levels of an additional 32 genes were significantly regulated by the interaction term. Within these 32 genes, previously reported PTSD candidates were identified, including FKBP5 and the IL18 and STAT pathways. Significant overrepresentation of steroid hormone transcription factor binding sites within these 32 transcripts was observed, highlighting the fact that the earlier-described genotype and PTSD-dependent differences in GR sensitivity could drive the observed gene expression pattern. Results were validated by reverse transcriptase–polymerase chain reaction and replicated in an independent sample (N=98). Conclusions These data suggest that the inheritance of GR sensitivity–moderating FKBP5 polymorphisms can determine specific types of hypothalamic-pituitary-adrenal axis dysfunction within PTSD, which are also reflected in gene-expression changes of a subset of GR-responsive genes. Thus, these findings indicate that functional variants in FKBP5 are associated with biologically distinct subtypes of PTSD. PMID:21536970

Association of vitamin D receptor gene polymorphisms with polycystic ovary syndrome among Indian women

PubMed Central

Dasgupta, Shilpi; Dutta, Joyita; Annamaneni, Sandhya; Kudugunti, Neelaveni; Battini, Mohan Reddy

2015-01-01

Background & objectives: The Vitamin-D receptor (VDR) regulates vitamin D levels and calcium metabolism in the body and these are known to be associated with endocrine dysfunctions, insulin resistance and type-2 diabetes in polycystic ovarian syndrome (PCOS). Studies on VDR polymorphisms among PCOS women are sparse. We undertook this study to investigate the association pattern of VDR polymorphisms (Cdx2, Fok1, Apa1 and Taq1) with PCOS among Indian women. Methods: For the present study, 250 women with PCOS and 250 normal healthy control women were selected from Hyderabad city, Telangana, India. The four VDR polymorphisms were genotyped and analysed using ASM-PCR (allele specific multiple PCR) and PCR-RFLP (restriction fragment length polymorphism). Results: The genotype and allele frequency distributions of only Cdx2 showed significant difference between the PCOS cases and control women, indicating protective role of this SNP against PCOS phenotype. However, significant association was observed between VDR genotypes and some of the PCOS specific clinical/biochemical traits. For example, Fok1 showed a significant genotypic difference for the presence of infertility and Cdx2 genotpes showed association with testosterone levels. Further, the two haplotypes, ACCA and ACTA, were found to be significantly associated with PCOS indicating haplotype specific risk. Interpretation & conclusions: Although VDR polymorphisms have not shown significant association with PCOS, in view of functional significance of the SNPs considered, one cannot yet rule out the possibility of their association with PCOS. Further, specifically designed studies on large cohorts are required to conclusively establish the role of VDR polymorphisms in PCOS, particularly including data on vitamin D levels. PMID:26458343

Genome-Wide Detection of Allele Specific Copy Number Variation Associated with Insulin Resistance in African Americans from the HyperGEN Study

PubMed Central

Pajewski, Nicholas M.; Kabagambe, Edmond K.; Gu, Charles C.; Pankow, Jim; North, Kari E.; Wilk, Jemma B.; Freedman, Barry I.; Franceschini, Nora; Broeckel, Uli; Tiwari, Hemant K.; Arnett, Donna K.

2011-01-01

African Americans have been understudied in genome wide association studies of diabetes and related traits. In the current study, we examined the joint association of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with fasting insulin and an index of insulin resistance (HOMA-IR) in the HyperGEN study, a family based study with proband ascertainment for hypertension. This analysis is restricted to 1,040 African Americans without diabetes. We generated allele specific CNV genotypes at 872,243 autosomal loci using Birdsuite, a freely available multi-stage program. Joint tests of association for SNPs and CNVs were performed using linear mixed models adjusting for covariates and familial relationships. Our results highlight SNPs associated with fasting insulin and HOMA-IR (rs6576507 and rs8026527, 3.7*10−7≤P≤1.1*10−5) near ATPase, class V, type 10A (ATP10A), and the L Type voltage dependent calcium channel (CACNA1D, rs1401492, P≤5.2*10−6). ATP10A belongs to a family of aminophospholipid-transporting ATPases and has been associated with type 2 diabetes in mice. CACNA1D has been linked to pancreatic beta cell generation in mice. The two most significant copy variable markers (rs10277702 and rs361367; P<2.0*10−4) were in the beta variable region of the T-cell receptor gene (TCRVB). Human and mouse TCR has been shown to mimic insulin and its receptor and could contribute to insulin resistance. Our findings differ from genome wide association studies of fasting insulin and other diabetes related traits in European populations, highlighting the continued need to investigate unique genetic influences for understudied populations such as African Americans. PMID:21901158

Genome-wide detection of allele specific copy number variation associated with insulin resistance in African Americans from the HyperGEN study.

PubMed

Irvin, Marguerite R; Wineinger, Nathan E; Rice, Treva K; Pajewski, Nicholas M; Kabagambe, Edmond K; Gu, Charles C; Pankow, Jim; North, Kari E; Wilk, Jemma B; Freedman, Barry I; Franceschini, Nora; Broeckel, Uli; Tiwari, Hemant K; Arnett, Donna K

2011-01-01

African Americans have been understudied in genome wide association studies of diabetes and related traits. In the current study, we examined the joint association of single nucleotide polymorphisms (SNPs) and copy number variants (CNVs) with fasting insulin and an index of insulin resistance (HOMA-IR) in the HyperGEN study, a family based study with proband ascertainment for hypertension. This analysis is restricted to 1,040 African Americans without diabetes. We generated allele specific CNV genotypes at 872,243 autosomal loci using Birdsuite, a freely available multi-stage program. Joint tests of association for SNPs and CNVs were performed using linear mixed models adjusting for covariates and familial relationships. Our results highlight SNPs associated with fasting insulin and HOMA-IR (rs6576507 and rs8026527, 3.7*10(-7)≤P≤1.1*10(-5)) near ATPase, class V, type 10A (ATP10A), and the L Type voltage dependent calcium channel (CACNA1D, rs1401492, P≤5.2*10(-6)). ATP10A belongs to a family of aminophospholipid-transporting ATPases and has been associated with type 2 diabetes in mice. CACNA1D has been linked to pancreatic beta cell generation in mice. The two most significant copy variable markers (rs10277702 and rs361367; P<2.0*10(-4)) were in the beta variable region of the T-cell receptor gene (TCRVB). Human and mouse TCR has been shown to mimic insulin and its receptor and could contribute to insulin resistance. Our findings differ from genome wide association studies of fasting insulin and other diabetes related traits in European populations, highlighting the continued need to investigate unique genetic influences for understudied populations such as African Americans.

Racial disparity in pathophysiologic pathways of preterm birth based on genetic variants

PubMed Central

Menon, Ramkumar; Pearce, Brad; Velez, Digna R; Merialdi, Mario; Williams, Scott M; Fortunato, Stephen J; Thorsen, Poul

2009-01-01

Objective To study pathophysiologic pathways in spontaneous preterm birth and possibly the racial disparity associating with maternal and fetal genetic variations, using bioinformatics tools. Methods A large scale candidate gene association study was performed on 1442 SNPs in 130 genes in a case (preterm birth < 36 weeks) control study (term birth > 37 weeks). Both maternal and fetal DNA from Caucasians (172 cases and 198 controls) and 279 African-Americans (82 cases and 197 controls) were used. A single locus association (genotypic) analysis followed by hierarchical clustering was performed, where clustering was based on p values for significant associations within each race. Using Ingenuity Pathway Analysis (IPA) software, known pathophysiologic pathways in both races were determined. Results From all SNPs entered into the analysis, the IPA mapped genes to specific disease functions. Gene variants in Caucasians were implicated in disease functions shared with other known disorders; specifically, dermatopathy, inflammation, and hematological disorders. This may reflect abnormal cervical ripening and decidual hemorrhage. In African-Americans inflammatory pathways were the most prevalent. In Caucasians, maternal gene variants showed the most prominent role in disease functions, whereas in African Americans it was fetal variants. The IPA software was used to generate molecular interaction maps that differed between races and also between maternal and fetal genetic variants. Conclusion Differences at the genetic level revealed distinct disease functions and operational pathways in African Americans and Caucasians in spontaneous preterm birth. Differences in maternal and fetal contributions in pregnancy outcome are also different between African Americans and Caucasians. These results present a set of explicit testable hypotheses regarding genetic associations with preterm birth in African Americans and Caucasians PMID:19527514

Simultaneous determination of seven informative Y chromosome SNPs to differentiate East Asian, European, and African populations.

PubMed

Muro, Tomonori; Iida, Reiko; Fujihara, Junko; Yasuda, Toshihiro; Watanabe, Yukina; Imamura, Shinji; Nakamura, Hiroaki; Kimura-Kataoka, Kaori; Yuasa, Isao; Toga, Tomoko; Takeshita, Haruo

2011-05-01

Identification of the population origin of an individual is very useful for crime investigators who need to narrow down a suspect based on specimens left at a crime scene. Single nucleotide polymorphisms of the Y chromosome (Y-SNPs) are a class of markers of interest to forensic investigators because many of the markers indicate regional specificity, thus providing useful information about the geographic origin of a subject. We selected seven informative Y-SNPs (M168, M130, JST021355, M96, P126, P196, and P234) to differentiate the three major population groups (East Asian, European, and African) and used them to develop forensic application. SNP genotyping was carried out by multiplex PCR reaction and multiplex single base extension (MSBE) reaction followed by capillary electrophoresis of extension products. This method can be used to assign a haplogroup from both degraded male DNA samples and DNA samples containing a mixture of female and male DNA through PCR primers that generate small amplicons (less than about 150 bp) and are highly specific for targets on the Y chromosome. The allelic state of each marker was definitively determined from a total of 791 males from the three major population groups. As expected, samples from the three major population groups showed Y-haplogroups common in the region of provenance: Y haplogroups C, D, and O for East Asians; IJ and R1 for Europeans; and AB and E for Africans. Published by Elsevier Ireland Ltd.

Regional selection of the brain size regulating gene CASC5 provides new insight into human brain evolution.

PubMed

Shi, Lei; Hu, Enzhi; Wang, Zhenbo; Liu, Jiewei; Li, Jin; Li, Ming; Chen, Hua; Yu, Chunshui; Jiang, Tianzi; Su, Bing

2017-02-01

Human evolution is marked by a continued enlargement of the brain. Previous studies on human brain evolution focused on identifying sequence divergences of brain size regulating genes between humans and nonhuman primates. However, the evolutionary pattern of the brain size regulating genes during recent human evolution is largely unknown. We conducted a comprehensive analysis of the brain size regulating gene CASC5 and found that in recent human evolution, CASC5 has accumulated many modern human specific amino acid changes, including two fixed changes and six polymorphic changes. Among human populations, 4 of the 6 amino acid polymorphic sites have high frequencies of derived alleles in East Asians, but are rare in Europeans and Africans. We proved that this between-population allelic divergence was caused by regional Darwinian positive selection in East Asians. Further analysis of brain image data of Han Chinese showed significant associations of the amino acid polymorphic sites with gray matter volume. Hence, CASC5 may contribute to the morphological and structural changes of the human brain during recent evolution. The observed between-population divergence of CASC5 variants was driven by natural selection that tends to favor a larger gray matter volume in East Asians.

Spatial and temporal distribution of the neutral polymorphisms in the last ZFX intron: analysis of the haplotype structure and genealogy.

PubMed Central

Jaruzelska, J; Zietkiewicz, E; Batzer, M; Cole, D E; Moisan, J P; Scozzari, R; Tavaré, S; Labuda, D

1999-01-01

With 10 segregating sites (simple nucleotide polymorphisms) in the last intron (1089 bp) of the ZFX gene we have observed 11 haplotypes in 336 chromosomes representing a worldwide array of 15 human populations. Two haplotypes representing 77% of all chromosomes were distributed almost evenly among four continents. Five of the remaining haplotypes were detected in Africa and 4 others were restricted to Eurasia and the Americas. Using the information about the ancestral state of the segregating positions (inferred from human-great ape comparisons), we applied coalescent analysis to estimate the age of the polymorphisms and the resulting haplotypes. The oldest haplotype, with the ancestral alleles at all the sites, was observed at low frequency only in two groups of African origin. Its estimated age of 740 to 1100 kyr corresponded to the time to the most recent common ancestor. The two most frequent worldwide distributed haplotypes were estimated at 550 to 840 and 260 to 400 kyr, respectively, while the age of the continentally restricted polymorphisms was 120 to 180 kyr and smaller. Comparison of spatial and temporal distribution of the ZFX haplotypes suggests that modern humans diverged from the common ancestral stock in the Middle Paleolithic era. Subsequent range expansion prevented substantial gene flow among continents, separating African groups from populations that colonized Eurasia and the New World. PMID:10388827

Spatial and temporal distribution of the neutral polymorphisms in the last ZFX intron: analysis of the haplotype structure and genealogy.

PubMed

Jaruzelska, J; Zietkiewicz, E; Batzer, M; Cole, D E; Moisan, J P; Scozzari, R; Tavaré, S; Labuda, D

1999-07-01

With 10 segregating sites (simple nucleotide polymorphisms) in the last intron (1089 bp) of the ZFX gene we have observed 11 haplotypes in 336 chromosomes representing a worldwide array of 15 human populations. Two haplotypes representing 77% of all chromosomes were distributed almost evenly among four continents. Five of the remaining haplotypes were detected in Africa and 4 others were restricted to Eurasia and the Americas. Using the information about the ancestral state of the segregating positions (inferred from human-great ape comparisons), we applied coalescent analysis to estimate the age of the polymorphisms and the resulting haplotypes. The oldest haplotype, with the ancestral alleles at all the sites, was observed at low frequency only in two groups of African origin. Its estimated age of 740 to 1100 kyr corresponded to the time to the most recent common ancestor. The two most frequent worldwide distributed haplotypes were estimated at 550 to 840 and 260 to 400 kyr, respectively, while the age of the continentally restricted polymorphisms was 120 to 180 kyr and smaller. Comparison of spatial and temporal distribution of the ZFX haplotypes suggests that modern humans diverged from the common ancestral stock in the Middle Paleolithic era. Subsequent range expansion prevented substantial gene flow among continents, separating African groups from populations that colonized Eurasia and the New World.

Evaluation of genetic association and expression reduction of TRPC1 in the development of diabetic nephropathy.

PubMed

Zhang, Dongying; Freedman, Barry I; Flekac, Milan; Santos, Elisabete; Hicks, Pamela J; Bowden, Donald W; Efendic, Suad; Brismar, Kerstin; Gu, Harvest F

2009-01-01

The TRPC1 gene on chromosome 3q22-24 resides within the linkage region for diabetic nephropathy (DN) in type 1 (T1D) and type 2 diabetes mellitus (T2D). A recent study has demonstrated that TRPC1 expression is reduced in the kidney of diabetic ZDF- and STZ-treated rats. The present study aimed to evaluate the genetic and functional role of TRPC1 in the development of DN. Genetic association study was performed with two independent cohorts, including 1,177 T1D European Americans with or without DN from GoKinD population and 850 African-American subjects with T2D-associated end-stage renal disease (ESRD), or with hypertensive (non-diabetic) ESRD, and nondiabetic controls. Seven tag SNP markers derived from HapMap data (phase II) were genotyped. TRPC1 gene expression was examined using real time RT-PCR. No significant association of TRPC1 DNA polymorphisms with DN or ERSD was found in GoKinD and African-American populations. TRPC1 gene mRNA expression in kidney was found to be trendily reduced in 12-week and significantly in 26-week-old db/db mice. TRPC1 genetic polymorphism may not fundamentally contribute to the development of DN, while reduction of the gene expression in kidney may be a late phenomenon of DN as seen in diabetic animal models. 2008 S. Karger AG, Basel.

An Examination of Lower Extremity Function and its Correlates in Older African American and White Men.

PubMed

Clay, Olivio J; Thorpe, Roland J; Wilkinson, Larrell L; Plaisance, Eric P; Crowe, Michael; Sawyer, Patricia; Brown, Cynthia J

2015-08-07

Maintaining functional status and reducing/eliminating health disparities in late life are key priorities. Older African Americans have been found to have worse lower extremity functioning than Whites, but little is known about potential differences in correlates between African American and White men. The goal of this investigation was to examine measures that could explain this racial difference and to identify race-specific correlates of lower extremity function. Data were analyzed for a sample of community-dwelling men. Linear regression models examined demographics, medical conditions, health behaviors, and perceived discrimination and mental health as correlates of an objective measure of lower extremity function, the Short Physical Performance Battery (SPPB). Scores on the SPPB have a potential range of 0 to 12 with higher scores corresponding to better functioning. The mean age of all men was 74.9 years (SD=6.5), and the sample was 50% African American and 53% rural. African American men had scores on the SPPB that were significantly lower than White men after adjusting for age, rural residence, marital status, education, and income difficulty (P<.01). Racial differences in cognitive functioning accounted for approximately 41% of the race effect on physical function. Additional models stratified by race revealed a pattern of similar correlates of the SPPB among African American and White men. The results of this investigation can be helpful for researchers and clinicians to aid in identifying older men who are at-risk for poor lower extremity function and in planning targeted interventions to help reduce disparities.

The impact of FADS genetic variants on ω6 polyunsaturated fatty acid metabolism in African Americans

PubMed Central

2011-01-01

Background Arachidonic acid (AA) is a long-chain omega-6 polyunsaturated fatty acid (PUFA) synthesized from the precursor dihomo-gamma-linolenic acid (DGLA) that plays a vital role in immunity and inflammation. Variants in the Fatty Acid Desaturase (FADS) family of genes on chromosome 11q have been shown to play a role in PUFA metabolism in populations of European and Asian ancestry; no work has been done in populations of African ancestry to date. Results In this study, we report that African Americans have significantly higher circulating levels of plasma AA (p = 1.35 × 10-48) and lower DGLA levels (p = 9.80 × 10-11) than European Americans. Tests for association in N = 329 individuals across 80 nucleotide polymorphisms (SNPs) in the Fatty Acid Desaturase (FADS) locus revealed significant association with AA, DGLA and the AA/DGLA ratio, a measure of enzymatic efficiency, in both racial groups (peak signal p = 2.85 × 10-16 in African Americans, 2.68 × 10-23 in European Americans). Ancestry-related differences were observed at an upstream marker previously associated with AA levels (rs174537), wherein, 79-82% of African Americans carry two copies of the G allele compared to only 42-45% of European Americans. Importantly, the allelic effect of the G allele, which is associated with enhanced conversion of DGLA to AA, on enzymatic efficiency was similar in both groups. Conclusions We conclude that the impact of FADS genetic variants on PUFA metabolism, specifically AA levels, is likely more pronounced in African Americans due to the larger proportion of individuals carrying the genotype associated with increased FADS1 enzymatic conversion of DGLA to AA. PMID:21599946

Novel Loci Associated with PR Interval in a Genome-Wide Association Study of Ten African American Cohorts

PubMed Central

Butler, Anne M.; Yin, Xiaoyan; Evans, Daniel S.; Nalls, Michael A.; Smith, Erin N.; Tanaka, Toshiko; Li, Guo; Buxbaum, Sarah G.; Whitsel, Eric A.; Alonso, Alvaro; Arking, Dan E.; Benjamin, Emelia J.; Berenson, Gerald S.; Bis, Josh C.; Chen, Wei; Deo, Rajat; Ellinor, Patrick T.; Heckbert, Susan R.; Heiss, Gerardo; Hsueh, Wen-Chi; Keating, Brendan J.; Kerr, Kathleen F.; Li, Yun; Limacher, Marian C.; Liu, Yongmei; Lubitz, Steven A.; Marciante, Kristin D.; Mehra, Reena; Meng, Yan A.; Newman, Anne B.; Newton-Cheh, Christopher; North, Kari E.; Palmer, Cameron D.; Psaty, Bruce M.; Quibrera, P. Miguel; Redline, Susan; Reiner, Alex P.; Rotter, Jerome I.; Schnabel, Renate B.; Schork, Nicholas J.; Singleton, Andrew B.; Smith, J. Gustav; Soliman, Elsayed Z.; Srinivasan, Sathanur R.; Zhang, Zhu-ming; Zonderman, Alan B.; Ferrucci, Luigi; Murray, Sarah S.; Evans, Michele K.; Sotoodehnia, Nona; Magnani, Jared W.; Avery, Christy L.

2013-01-01

Background The PR interval (PR) as measured by the resting, standard 12-lead electrocardiogram (ECG) reflects the duration of atrial/atrioventricular nodal depolarization. Substantial evidence exists for a genetic contribution to PR, including genome-wide association studies that have identified common genetic variants at nine loci influencing PR in populations of European and Asian descent. However, few studies have examined loci associated with PR in African Americans. Methods and Results We present results from the largest genome-wide association study to date of PR in 13,415 adults of African descent from ten cohorts. We tested for association between PR (ms) and approximately 2.8 million genotyped and imputed single nucleotide polymorphisms. Imputation was performed using HapMap 2 YRI and CEU panels. Study-specific results, adjusted for global ancestry and clinical correlates of PR, were meta-analyzed using the inverse variance method. Variation in genome-wide test statistic distributions was noted within studies (lambda range: 0.9–1.1), although not after genomic control correction was applied to the overall meta-analysis (lambda: 1.008). In addition to generalizing previously reported associations with MEIS1, SCN5A, ARHGAP24, CAV1, and TBX5 to African American populations at the genome-wide significance level (P<5.0×10−8), we also identified a novel locus: ITGA9, located in a region previously implicated in SCN5A expression. The 3p21 region harboring SCN5A also contained two additional independent secondary signals influencing PR (P<5.0×10−8). Conclusions This study demonstrates the ability to map novel loci in African Americans as well as the generalizability of loci associated with PR across populations of African, European and Asian descent. PMID:23139255

APOL1 nephropathy risk variants are associated with altered high-density lipoprotein profiles in African Americans.

PubMed

Gutiérrez, Orlando M; Judd, Suzanne E; Irvin, Marguerite R; Zhi, Degui; Limdi, Nita; Palmer, Nicholette D; Rich, Stephen S; Sale, Michèle M; Freedman, Barry I

2016-04-01

Two independent coding variants in the apolipoprotein L1 gene (APOL1), G1 and G2, strongly associate with nephropathy in African Americans; associations with cardiovascular disease are more controversial. Although APOL1 binds plasma high-density lipoproteins (HDLs), data on APOL1 risk variant associations with HDL subfractions are sparse. Two APOL1 G1 single nucleotide polymorphisms and the G2 insertion/deletion polymorphism were genotyped in 2010 Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study participants with nuclear magnetic resonance spectroscopy-based lipoprotein subfraction measurements. Linear regression was used to model associations between numbers of APOL1 G1/G2 risk variants and HDL subfractions, adjusting for demographic, clinical and ancestral covariates. Female sex and higher percentage of African ancestry were positively associated with the number of APOL1 G1/G2 risk alleles. In the unadjusted analysis, mean (standard error) small HDL concentrations (μmol/L) for participants with zero, one and two G1/G2 risk alleles were 19.0 (0.2), 19.7 (0.2) and 19.9 (0.4), respectively (P = 0.02). Adjustment for age, sex, diabetes and African ancestry did not change the results but strengthened the statistical significance (P = 0.004). No significant differences in large or medium HDL, very low-density lipoprotein or low-density lipoprotein particle concentrations were observed by APOL1 genotype. Greater numbers of APOL1 G1/G2 risk alleles were associated with higher small HDL particle concentrations in African Americans. These results may suggest novel areas of investigation to uncover reasons for the association between APOL1 risk variants with adverse outcomes in African Americans. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

APOL1 nephropathy risk variants are associated with altered high-density lipoprotein profiles in African Americans

PubMed Central

Gutiérrez, Orlando M.; Judd, Suzanne E.; Irvin, Marguerite R.; Zhi, Degui; Limdi, Nita; Palmer, Nicholette D.; Rich, Stephen S.; Sale, Michèle M.; Freedman, Barry I.

2016-01-01

Background Two independent coding variants in the apolipoprotein L1 gene (APOL1), G1 and G2, strongly associate with nephropathy in African Americans; associations with cardiovascular disease are more controversial. Although APOL1 binds plasma high-density lipoproteins (HDLs), data on APOL1 risk variant associations with HDL subfractions are sparse. Methods Two APOL1 G1 single nucleotide polymorphisms and the G2 insertion/deletion polymorphism were genotyped in 2010 Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study participants with nuclear magnetic resonance spectroscopy-based lipoprotein subfraction measurements. Linear regression was used to model associations between numbers of APOL1 G1/G2 risk variants and HDL subfractions, adjusting for demographic, clinical and ancestral covariates. Results Female sex and higher percentage of African ancestry were positively associated with the number of APOL1 G1/G2 risk alleles. In the unadjusted analysis, mean (standard error) small HDL concentrations (μmol/L) for participants with zero, one and two G1/G2 risk alleles were 19.0 (0.2), 19.7 (0.2) and 19.9 (0.4), respectively (P = 0.02). Adjustment for age, sex, diabetes and African ancestry did not change the results but strengthened the statistical significance (P = 0.004). No significant differences in large or medium HDL, very low-density lipoprotein or low-density lipoprotein particle concentrations were observed by APOL1 genotype. Conclusions Greater numbers of APOL1 G1/G2 risk alleles were associated with higher small HDL particle concentrations in African Americans. These results may suggest novel areas of investigation to uncover reasons for the association between APOL1 risk variants with adverse outcomes in African Americans. PMID:26152403

Mutations and polymorphisms in FSH receptor: functional implications in human reproduction.

PubMed

Desai, Swapna S; Roy, Binita Sur; Mahale, Smita D

2013-12-01

FSH brings about its physiological actions by activating a specific receptor located on target cells. Normal functioning of the FSH receptor (FSHR) is crucial for follicular development and estradiol production in females and for the regulation of Sertoli cell function and spermatogenesis in males. In the last two decades, the number of inactivating and activating mutations, single nucleotide polymorphisms, and spliced variants of FSHR gene has been identified in selected infertile cases. Information on genotype-phenotype correlation and in vitro functional characterization of the mutants has helped in understanding the possible genetic cause for female infertility in affected individuals. The information is also being used to dissect various extracellular and intracellular events involved in hormone-receptor interaction by studying the differences in the properties of the mutant receptor when compared with WT receptor. Studies on polymorphisms in the FSHR gene have shown variability in clinical outcome among women treated with FSH. These observations are being explored to develop molecular markers to predict the optimum dose of FSH required for controlled ovarian hyperstimulation. Pharmacogenetics is an emerging field in this area that aims at designing individual treatment protocols for reproductive abnormalities based on FSHR gene polymorphisms. The present review discusses the current knowledge of various genetic alterations in FSHR and their impact on receptor function in the female reproductive system.

The social psychological costs of racial segmentation in the workplace: a study of African Americans' well-being.

PubMed

Forman, Tyrone A

2003-09-01

Although several studies have documented how social-structural constraints impair psychological functioning, few have considered how race-related structural constraints impair African Americans' psychological functioning. This study focuses on an under-studied form of race-related structural constraints: racial segmentation in the workplace. Specifically, I examine the association between perceived workplace racial segmentation, conceived and assessed from a social psychological perspective, and African Americans' psychological well-being. The magnitude and consistency of the relationship is evaluated across both a national sample and a local probability sample of African Americans. Findings across the two samples indicate a modest but consistent negative relationship between perceived racial segmentation and psychological well-being. In addition, this association remains significant after controlling for perceived discrimination as well as sociodemographic and occupational characteristics. Consistent with prior research on relative deprivation, the adverse influence of perceived racial segmentation on well-being was stronger among higher socioeconomic status African Americans than lower socioeconomic African Americans.

Association of Functional Polymorphism rs2231142 (Q141K) in the ABCG2 Gene With Serum Uric Acid and Gout in 4 US Populations

PubMed Central

Zhang, Lili; Spencer, Kylee L.; Voruganti, V. Saroja; Jorgensen, Neal W.; Fornage, Myriam; Best, Lyle G.; Brown-Gentry, Kristin D.; Cole, Shelley A.; Crawford, Dana C.; Deelman, Ewa; Franceschini, Nora; Gaffo, Angelo L.; Glenn, Kimberly R.; Heiss, Gerardo; Jenny, Nancy S.; Kottgen, Anna; Li, Qiong; Liu, Kiang; Matise, Tara C.; North, Kari E.; Umans, Jason G.; Kao, W. H. Linda

2013-01-01

A loss-of-function mutation (Q141K, rs2231142) in the ATP-binding cassette, subfamily G, member 2 gene (ABCG2) has been shown to be associated with serum uric acid levels and gout in Asians, Europeans, and European and African Americans; however, less is known about these associations in other populations. Rs2231142 was genotyped in 22,734 European Americans, 9,720 African Americans, 3,849 Mexican Americans, and 3,550 American Indians in the Population Architecture using Genomics and Epidemiology (PAGE) Study (2008–2012). Rs2231142 was significantly associated with serum uric acid levels (P = 2.37 × 10−67, P = 3.98 × 10−5, P = 6.97 × 10−9, and P = 5.33 × 10−4 in European Americans, African Americans, Mexican Americans, and American Indians, respectively) and gout (P = 2.83 × 10−10, P = 0.01, and P = 0.01 in European Americans, African Americans, and Mexican Americans, respectively). Overall, the T allele was associated with a 0.24-mg/dL increase in serum uric acid level (P = 1.37 × 10−80) and a 1.75-fold increase in the odds of gout (P = 1.09 × 10−12). The association between rs2231142 and serum uric acid was significantly stronger in men, postmenopausal women, and hormone therapy users compared with their counterparts. The association with gout was also significantly stronger in men than in women. These results highlight a possible role of sex hormones in the regulation of ABCG2 urate transporter and its potential implications for the prevention, diagnosis, and treatment of hyperuricemia and gout. PMID:23552988

Two Theileria parva CD8 T Cell Antigen Genes Are More Variable in Buffalo than Cattle Parasites, but Differ in Pattern of Sequence Diversity

PubMed Central

Pelle, Roger; Graham, Simon P.; Njahira, Moses N.; Osaso, Julius; Saya, Rosemary M.; Odongo, David O.; Toye, Philip G.; Spooner, Paul R.; Musoke, Anthony J.; Mwangi, Duncan M.; Taracha, Evans L. N.; Morrison, W. Ivan; Weir, William; Silva, Joana C.; Bishop, Richard P.

2011-01-01

Background Theileria parva causes an acute fatal disease in cattle, but infections are asymptomatic in the African buffalo (Syncerus caffer). Cattle can be immunized against the parasite by infection and treatment, but immunity is partially strain specific. Available data indicate that CD8+ T lymphocyte responses mediate protection and, recently, several parasite antigens recognised by CD8+ T cells have been identified. This study set out to determine the nature and extent of polymorphism in two of these antigens, Tp1 and Tp2, which contain defined CD8+ T-cell epitopes, and to analyse the sequences for evidence of selection. Methodology/Principal Findings Partial sequencing of the Tp1 gene and the full-length Tp2 gene from 82 T. parva isolates revealed extensive polymorphism in both antigens, including the epitope-containing regions. Single nucleotide polymorphisms were detected at 51 positions (∼12%) in Tp1 and in 320 positions (∼61%) in Tp2. Together with two short indels in Tp1, these resulted in 30 and 42 protein variants of Tp1 and Tp2, respectively. Although evidence of positive selection was found for multiple amino acid residues, there was no preferential involvement of T cell epitope residues. Overall, the extent of diversity was much greater in T. parva isolates originating from buffalo than in isolates known to be transmissible among cattle. Conclusions/Significance The results indicate that T. parva parasites maintained in cattle represent a subset of the overall T. parva population, which has become adapted for tick transmission between cattle. The absence of obvious enrichment for positively selected amino acid residues within defined epitopes indicates either that diversity is not predominantly driven by selection exerted by host T cells, or that such selection is not detectable by the methods employed due to unidentified epitopes elsewhere in the antigens. Further functional studies are required to address this latter point. PMID:21559495

Two Theileria parva CD8 T cell antigen genes are more variable in buffalo than cattle parasites, but differ in pattern of sequence diversity.

PubMed

Pelle, Roger; Graham, Simon P; Njahira, Moses N; Osaso, Julius; Saya, Rosemary M; Odongo, David O; Toye, Philip G; Spooner, Paul R; Musoke, Anthony J; Mwangi, Duncan M; Taracha, Evans L N; Morrison, W Ivan; Weir, William; Silva, Joana C; Bishop, Richard P

2011-04-29

Theileria parva causes an acute fatal disease in cattle, but infections are asymptomatic in the African buffalo (Syncerus caffer). Cattle can be immunized against the parasite by infection and treatment, but immunity is partially strain specific. Available data indicate that CD8(+) T lymphocyte responses mediate protection and, recently, several parasite antigens recognised by CD8(+) T cells have been identified. This study set out to determine the nature and extent of polymorphism in two of these antigens, Tp1 and Tp2, which contain defined CD8(+) T-cell epitopes, and to analyse the sequences for evidence of selection. Partial sequencing of the Tp1 gene and the full-length Tp2 gene from 82 T. parva isolates revealed extensive polymorphism in both antigens, including the epitope-containing regions. Single nucleotide polymorphisms were detected at 51 positions (∼12%) in Tp1 and in 320 positions (∼61%) in Tp2. Together with two short indels in Tp1, these resulted in 30 and 42 protein variants of Tp1 and Tp2, respectively. Although evidence of positive selection was found for multiple amino acid residues, there was no preferential involvement of T cell epitope residues. Overall, the extent of diversity was much greater in T. parva isolates originating from buffalo than in isolates known to be transmissible among cattle. The results indicate that T. parva parasites maintained in cattle represent a subset of the overall T. parva population, which has become adapted for tick transmission between cattle. The absence of obvious enrichment for positively selected amino acid residues within defined epitopes indicates either that diversity is not predominantly driven by selection exerted by host T cells, or that such selection is not detectable by the methods employed due to unidentified epitopes elsewhere in the antigens. Further functional studies are required to address this latter point.

AGXT2 rs37369 polymorphism predicts the renal function in patients with chronic heart failure.

PubMed

Hu, Xiao-Lei; Zeng, Wen-Jing; Li, Mu-Peng; Yang, Yong-Long; Kuang, Da-Bin; Li, He; Zhang, Yan-Jiao; Jiang, Chun; Peng, Li-Ming; Qi, Hong; Zhang, Ke; Chen, Xiao-Ping

2017-12-30

Patients with chronic heart failure (CHF) are often accompanied with varying degrees of renal diseases. The purpose of this study was to identify rs37369 polymorphism of AGXT2 specific to the renal function of CHF patients. A total of 1012 southern Chinese participants, including 487 CHF patients without history of renal diseases and 525 healthy volunteers, were recruited for this study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotypes of AGXT2 rs37369 polymorphism. Levels of blood urea nitrogen (BUN) and serum creatinine (SCr) were detected to indicate the renal function of the participants. BUN level was significantly higher in CHF patients without history of renal diseases compared with healthy volunteers (p=0.000). And the similar result was also obtained for SCr (p=0.000). Besides, our results indicated that the level of BUN correlated significantly with SCr in both the CHF patients without renal diseases (r=0.4533, p<0.0001) and volunteers (r=0.2489, p<0.0001). Furthermore, we found that the AGXT2 rs37369 polymorphism could significantly affect the level of BUN in CHF patients without history of renal diseases (p=0.036, AA+AG vs GG). Patients with rs37369 GG genotype showed a significantly reduced level of BUN compared to those with the AA genotype (p=0.024), and the significant difference was still observed in the smokers of CHF patients without renal diseases (p=0.023). In conclusion, we found that CHF might induce the impairment of kidney and cause deterioration of renal function. AGXT2 rs37369 polymorphism might affect the renal function of CHF patients free from renal diseases, especially in patients with cigarette smoking. Copyright © 2017. Published by Elsevier B.V.

Genetic risk variants in African Americans with multiple sclerosis

PubMed Central

Isobe, Noriko; Gourraud, Pierre-Antoine; Harbo, Hanne F.; Caillier, Stacy J.; Santaniello, Adam; Khankhanian, Pouya; Maiers, Martin; Spellman, Stephen; Cereb, Nezih; Yang, SooYoung; Pando, Marcelo J.; Piccio, Laura; Cross, Anne H.; De Jager, Philip L.; Cree, Bruce A.C.; Hauser, Stephen L.

2013-01-01

Objectives: To assess the association of established multiple sclerosis (MS) risk variants in 3,254 African Americans (1,162 cases and 2,092 controls). Methods: Human leukocyte antigen (HLA)-DRB1, HLA-DQB1, and HLA-A alleles were typed by molecular techniques. Single nucleotide polymorphism (SNP) genotyping was conducted for 76 MS-associated SNPs and 52 ancestry informative marker SNPs selected throughout the genome. Self-declared ancestry was refined by principal component analysis of the ancestry informative marker SNPs. An ancestry-adjusted multivariate model was applied to assess genetic associations. Results: The following major histocompatibility complex risk alleles were replicated: HLA-DRB1*15:01 (odds ratio [OR] = 2.02 [95% confidence interval: 1.54–2.63], p = 2.50e-07), HLA-DRB1*03:01 (OR = 1.58 [1.29–1.94], p = 1.11e-05), as well as HLA-DRB1*04:05 (OR = 2.35 [1.26–4.37], p = 0.007) and the African-specific risk allele of HLA-DRB1*15:03 (OR = 1.26 [1.05–1.51], p = 0.012). The protective association of HLA-A*02:01 was confirmed (OR = 0.72 [0.55–0.93], p = 0.013). None of the HLA-DQB1 alleles were associated with MS. Using a significance threshold of p < 0.01, outside the major histocompatibility complex region, 8 MS SNPs were also found to be associated with MS in African Americans. Conclusion: MS genetic risk in African Americans only partially overlaps with that of Europeans and could explain the difference of MS prevalence between populations. PMID:23771490

Genetic polymorphism analysis of cytochrome P4502E1 (CYP2E1) in a Chinese Tibetan population

PubMed Central

Wang, Li; Ren, Guoxia; Li, Jingjie; Zhu, Linhao; Niu, Fanglin; Yan, Mengdan; Li, Jing; Yuan, Dongya; Jin, Tianbo

2017-01-01

Abstract Cytochrome P4502E1 (CYP2E1) gene genetic polymorphisms vary markedly in frequency among different ethnic and racial groups. We studied the genotype distributions and allele frequencies of 3 CYP2E1 polymorphisms: CYP2E1∗1A, CYP2E1∗7A, and CYP2E1∗7C by polymerase chain reaction technique in a sample of 100 healthy subjects representing Tibetan population. The frequencies of CYP2E1∗1A, ∗7A, and ∗7C alleles were 0.705, 0.125, and 0.170, respectively. Compared with other populations, we found that the allele frequencies of the variants −352A>G (rs2070672) and −333A>T (rs2070673) in this Tibetan population have significant differences compared with European-American, African-American, Japanese, Korean, and other different geographic areas in Chinese Han population. Furthermore, the results of protein prediction revealed that the variant 6397G>A (rs61710826) could influence the protein structure and function. These findings in this study would be valuable for pharmacogenetics for drug therapy and drug discovery. However, further studies in larger samples are warranted to confirm our results. PMID:29381998

Primary hyperoxaluria type 1: update and additional mutation analysis of the AGXT gene.

PubMed

Williams, Emma L; Acquaviva, Cecile; Amoroso, Antonio; Chevalier, Francoise; Coulter-Mackie, Marion; Monico, Carla G; Giachino, Daniela; Owen, Tricia; Robbiano, Angela; Salido, Eduardo; Waterham, Hans; Rumsby, Gill

2009-06-01

Primary hyperoxaluria type 1 (PH1) is an autosomal recessive, inherited disorder of glyoxylate metabolism arising from a deficiency of the alanine:glyoxylate aminotransferase (AGT) enzyme, encoded by the AGXT gene. The disease is manifested by excessive endogenous oxalate production, which leads to impaired renal function and associated morbidity. At least 146 mutations have now been described, 50 of which are newly reported here. The mutations, which occur along the length of the AGXT gene, are predominantly single-nucleotide substitutions (75%), 73 are missense, 19 nonsense, and 18 splice mutations; but 36 major and minor deletions and insertions are also included. There is little association of mutation with ethnicity, the most obvious exception being the p.Ile244Thr mutation, which appears to have North African/Spanish origins. A common, polymorphic variant encoding leucine at codon 11, the so-called minor allele, has significantly lower catalytic activity in vitro, and has a higher frequency in PH1 compared to the rest of the population. This polymorphism influences enzyme targeting in the presence of the most common Gly170Arg mutation and potentiates the effect of several other pathological sequence variants. This review discusses the spectrum of AGXT mutations and polymorphisms, their clinical significance, and their diagnostic relevance.

Genetic moderation of child maltreatment effects on depression and internalizing symptoms by 5-HTTLPR, BDNF, NET, and CRHR1 genes in African-American children

PubMed Central

Cicchetti, Dante; Rogosch, Fred A.

2014-01-01

Genetic moderation of the effects of child maltreatment on depression and internalizing symptoms was investigated in a sample of low-income maltreated and nonmaltreated African-American children (N = 1,096). Lifetime child maltreatment experiences were independently coded from Child Protective Services records and maternal report. Child depression and internalizing problems were assessed in the context of a summer research camp by self-report (Children’s Depression Inventory, CDI) and adult counselor-report (Teacher Report Form, TRF). DNA was obtained from buccal cell or saliva samples and genotyped for polymorphisms of the following genes: 5-HTTLPR, BDNF, NET, and CRHR1. ANCOVAs with age and gender as covariates were conducted, with maltreatment status and respective polymorphism as main effects and their GxE interactions. Maltreatment consistently was associated with higher CDI and TRF symptoms. Results for child self-report symptoms indicated a GxE interaction for BDNF and maltreatment. Additionally, BDNF and tri-allelic 5-HTTLPR interacted with child maltreatment in a GxGxE interaction. Analyses for counselor-report of child anxiety/depression symptoms on the TRF indicated moderation of child maltreatment effects by tri-allelic 5-HTTLPR. These effects were elaborated based on variation in developmental timing of maltreatment experiences. NET was found to further moderate the GxE interaction of 5-HTTLPR and maltreatment status revealing a GxGxE interaction. This GxGxE was extended by consideration of variation in maltreatment subtype experiences. Finally, GxGxE effects were observed for the co-action of BDNF and the CRHR1 haplotype. The findings illustrate the variable influence of specific genotypes in GxE interactions based on variation in maltreatment experiences and the importance of a multi-genic approach for understanding influences on depression and internalizing symptoms among African-American children. PMID:25422957

Association of a functional IRF7 variant with systemic lupus erythematosus.

PubMed

Fu, Qiong; Zhao, Jian; Qian, Xiaoxia; Wong, Jonathan L H; Kaufman, Kenneth M; Yu, C Yung; Mok, Mo Yin; Harley, John B; Guthridge, Joel M; Song, Yeong Wook; Cho, Soo-Kyung; Bae, Sang-Cheol; Grossman, Jennifer M; Hahn, Bevra H; Arnett, Frank C; Shen, Nan; Tsao, Betty P

2011-03-01

A previous genome-wide association study conducted in a population of European ancestry identified rs4963128, a KIAA1542 single-nucleotide polymorphism (SNP) 23 kb telomeric to IRF7 (the gene for interferon regulatory factor 7 [IRF-7]), to be strongly associated with systemic lupus erythematosus (SLE). This study was undertaken to investigate whether genetic polymorphism within IRF7 is a risk factor for the development of SLE. We genotyped one KIAA1542 SNP (rs4963128) and one IRF7 SNP (rs1131665 [Q412R]) in an Asian population (1,302 cases, 1,479 controls), to assess their association with SLE. Subsequently, rs1131665 was further genotyped in independent panels of Chinese subjects (528 cases, 527 controls), European American subjects (446 cases, 461 controls), and African American subjects (159 cases, 115 controls) by TaqMan genotyping assay, to seek confirmation of association in various ethnic groups. A luciferase reporter assay was used to assess the effect of Q412R polymorphism on the activation of IRF-7. Consistent association of rs1131665 (Q412R) with SLE was identified in Asian, European American, and African American populations (total 2,435 cases and 2,582 controls) (P(meta) = 6.18 × 10(-6) , odds ratio 1.42 [95% confidence interval 1.22-1.65]). Expression of the IRF7 412Q risk allele resulted in a 2-fold increase in interferon-stimulated response element transcriptional activity compared with expression of IRF7 412R (P = 0.0003), suggesting that IRF7 412Q confers elevated IRF-7 activity and may therefore affect a downstream interferon pathway. These findings show that the major allele of a nonsynonymous SNP, rs1131665 (412Q) in IRF7, confers elevated activation of IRF-7 and predisposes to the development of SLE in multiple ethnic groups. This result provides direct genetic evidence that IRF7 may be a risk gene for human SLE. Copyright © 2011 by the American College of Rheumatology.

Lack of integrase inhibitors associated resistance mutations among HIV-1C isolates.

PubMed

Mulu, Andargachew; Maier, Melanie; Liebert, Uwe Gerd

2015-12-01

Although biochemical analysis of HIV-1 integrase enzyme suggested the use of integrase inhibitors (INIs) against HIV-1C, different viral subtypes may favor different mutational pathways potentially leading to varying levels of drug resistance. Thus, the aim of this study was to search for the occurrence and natural evolution of integrase polymorphisms and/or resistance mutations in HIV-1C Ethiopian clinical isolates prior to the introduction of INIs. Plasma samples from chronically infected drug naïve patients (N = 45), of whom the PR and RT sequence was determined previously, were used to generate population based sequences of HIV-1 integrase. HIV-1 subtype was determined using the REGA HIV-1 subtyping tool. Resistance mutations were interpreted according to the Stanford HIV drug resistance database ( http://hivdb.stanford.edu ) and the updated International Antiviral Society (IAS)-USA mutation lists. Moreover, rates of polymorphisms in the current isolates were compared with South African and global HIV-1C isolates. All subjects were infected with HIV-1C concordant to the protease (PR) and reverse transcriptase (RT) regions. Neither major resistance-associated IN mutations (T66I/A/K, E92Q/G, T97A, Y143HCR, S147G, Q148H/R/K, and N155H) nor silent mutations known to change the genetic barrier were observed. Moreover, the DDE-catalytic motif (D64G/D116G/E152 K) and signature HHCC zinc-binding motifs at codon 12, 16, 40 and 43 were found to be highly conserved. However, compared to other South African subtype C isolates, the rate of polymorphism was variable at various positions. Although the sample size is small, the findings suggest that this drug class could be effective in Ethiopia and other southern African countries where HIV-1C is predominantly circulating. The data will contribute to define the importance of integrase polymorphism and to improve resistance interpretation algorithms in HIV-1C isolates.

Analysis of the Functional Polymorphism in the Cytochrome P450 CYP2C8 Gene rs11572080 with Regard to Colorectal Cancer Risk

PubMed Central

Ladero, José M.; Agúndez, José A. G.; Martínez, Carmen; Amo, Gemma; Ayuso, Pedro; García-Martín, Elena

2012-01-01

In addition to the known effects on drug metabolism and response, functional polymorphisms of genes coding for xenobiotic-metabolizing enzymes (XME) play a role in cancer. Genes coding for XME act as low-penetrance genes and confer modest but consistent and significant risks for a variety of cancers related to the interaction of environmental and genetic factors. Consistent evidence supports a role for polymorphisms of the cytochrome P450 CYP2C9 gene as a protecting factor for colorectal cancer susceptibility. It has been shown that CYP2C8 and CYP2C9 overlap in substrate specificity. Because CYP2C8 has the common functional polymorphisms rs11572080 and rs10509681 (CYP2C8*3), it could be speculated that part of the findings attributed to CYP2C9 polymorphisms may actually be related to the presence of polymorphisms in the CYP2C8 gene. Nevertheless, little attention has been paid to the role of the CYP2C8 polymorphism in colorectal cancer. We analyzed the influence of the CYP2C8*3 allele in the risk of developing colorectal cancer in genomic DNA from 153 individuals suffering colorectal cancer and from 298 age- and gender-matched control subjects. Our findings do not support any effect of the CYP2C8*3 allele (OR for carriers of functional CYP2C8 alleles = 0.50 (95% CI = 0.16–1.59; p = 0.233). The absence of a relative risk related to CYP2C8*3 did not vary depending on the tumor site. We conclude that the risk of developing colorectal cancer does not seem to be related to the commonest functional genetic variation in the CYP2C8 gene. PMID:23420707

Studying Individual Plant AOX Gene Functionality in Early Growth Regulation: A New Approach.

PubMed

Arnholdt-Schmitt, Birgit; Patil, Vinod Kumar

2017-01-01

AOX1 and AOX2 genes are thought to play different physiological roles. Whereas AOX1 is typically expected to associate to stress and growth responses, AOX2 was more often found to be linked to development and housekeeping functions. However, this view is questioned by several adverse observations. For example, co-regulated expression for DcAOX1 and DcAOX2a genes was recently reported during growth induction in carrot (Daucus carota L.). Early expression peaks for both genes during the lag phase of growth coincided with a critical time point for biomass prediction, a result achieved by applying calorespirometry. The effect of both AOX family member genes cannot easily be separated. However, separate functional analysis is required in order to identify important gene-specific polymorphisms or patterns of polymorphisms for functional marker development and its use in breeding. Specifically, a methodology is missing that enables studying functional effects of individual genes or polymorphisms/polymorphic patterns on early growth regulation.This protocol aims to provide the means for identifying plant alternative oxidase (AOX) gene variants as functional markers for early growth regulation. Prerequisite for applying this protocol is available Schizosaccharomyces pombe strains that were transformed with individual AOX genes following published protocols from Anthony Moore's group (Albury et al., J Biol Chem 271:17062-17066, 1996; Affourtit et al., J Biol Chem 274:6212-6218, 1999). The novelty of the present protocol comes by modifying yeast cell densities in a way that allows studying critical qualitative and quantitative effects of AOX gene variants (isoenzymes or polymorphic genes) during the early phase of growth. Calorimetry is used as a novel tool to confirm differences obtained by optical density measurements in early growth regulation by metabolic phenotyping (released heat rates). This protocol enables discriminating between AOX genes that inhibit growth and AOX genes that enhance growth under comparable conditions. It also allows studying dependency of AOX gene effects on gene copy number. The protocol can also be combined with laser microdissection of individual cells from target tissues for specified breeding traits.

Fine-mapping and initial characterization of QT interval loci in African Americans.

PubMed

Avery, Christy L; Sethupathy, Praveen; Buyske, Steven; He, Qianchuan; Lin, Dan-Yu; Arking, Dan E; Carty, Cara L; Duggan, David; Fesinmeyer, Megan D; Hindorff, Lucia A; Jeff, Janina M; Klein, Liviu; Patton, Kristen K; Peters, Ulrike; Shohet, Ralph V; Sotoodehnia, Nona; Young, Alicia M; Kooperberg, Charles; Haiman, Christopher A; Mohlke, Karen L; Whitsel, Eric A; North, Kari E

2012-01-01

The QT interval (QT) is heritable and its prolongation is a risk factor for ventricular tachyarrhythmias and sudden death. Most genetic studies of QT have examined European ancestral populations; however, the increased genetic diversity in African Americans provides opportunities to narrow association signals and identify population-specific variants. We therefore evaluated 6,670 SNPs spanning eleven previously identified QT loci in 8,644 African American participants from two Population Architecture using Genomics and Epidemiology (PAGE) studies: the Atherosclerosis Risk in Communities study and Women's Health Initiative Clinical Trial. Of the fifteen known independent QT variants at the eleven previously identified loci, six were significantly associated with QT in African American populations (P≤1.20×10(-4)): ATP1B1, PLN1, KCNQ1, NDRG4, and two NOS1AP independent signals. We also identified three population-specific signals significantly associated with QT in African Americans (P≤1.37×10(-5)): one at NOS1AP and two at ATP1B1. Linkage disequilibrium (LD) patterns in African Americans assisted in narrowing the region likely to contain the functional variants for several loci. For example, African American LD patterns showed that 0 SNPs were in LD with NOS1AP signal rs12143842, compared with European LD patterns that indicated 87 SNPs, which spanned 114.2 Kb, were in LD with rs12143842. Finally, bioinformatic-based characterization of the nine African American signals pointed to functional candidates located exclusively within non-coding regions, including predicted binding sites for transcription factors such as TBX5, which has been implicated in cardiac structure and conductance. In this detailed evaluation of QT loci, we identified several African Americans SNPs that better define the association with QT and successfully narrowed intervals surrounding established loci. These results demonstrate that the same loci influence variation in QT across multiple populations, that novel signals exist in African Americans, and that the SNPs identified as strong candidates for functional evaluation implicate gene regulatory dysfunction in QT prolongation.

Fine-Mapping and Initial Characterization of QT Interval Loci in African Americans

PubMed Central

Avery, Christy L.; Sethupathy, Praveen; Buyske, Steven; He, Qianchuan; Lin, Dan-Yu; Arking, Dan E.; Carty, Cara L.; Duggan, David; Fesinmeyer, Megan D.; Hindorff, Lucia A.; Jeff, Janina M.; Klein, Liviu; Patton, Kristen K.; Peters, Ulrike; Shohet, Ralph V.; Sotoodehnia, Nona; Young, Alicia M.; Kooperberg, Charles; Haiman, Christopher A.; Mohlke, Karen L.; Whitsel, Eric A.; North, Kari E.

2012-01-01

The QT interval (QT) is heritable and its prolongation is a risk factor for ventricular tachyarrhythmias and sudden death. Most genetic studies of QT have examined European ancestral populations; however, the increased genetic diversity in African Americans provides opportunities to narrow association signals and identify population-specific variants. We therefore evaluated 6,670 SNPs spanning eleven previously identified QT loci in 8,644 African American participants from two Population Architecture using Genomics and Epidemiology (PAGE) studies: the Atherosclerosis Risk in Communities study and Women's Health Initiative Clinical Trial. Of the fifteen known independent QT variants at the eleven previously identified loci, six were significantly associated with QT in African American populations (P≤1.20×10−4): ATP1B1, PLN1, KCNQ1, NDRG4, and two NOS1AP independent signals. We also identified three population-specific signals significantly associated with QT in African Americans (P≤1.37×10−5): one at NOS1AP and two at ATP1B1. Linkage disequilibrium (LD) patterns in African Americans assisted in narrowing the region likely to contain the functional variants for several loci. For example, African American LD patterns showed that 0 SNPs were in LD with NOS1AP signal rs12143842, compared with European LD patterns that indicated 87 SNPs, which spanned 114.2 Kb, were in LD with rs12143842. Finally, bioinformatic-based characterization of the nine African American signals pointed to functional candidates located exclusively within non-coding regions, including predicted binding sites for transcription factors such as TBX5, which has been implicated in cardiac structure and conductance. In this detailed evaluation of QT loci, we identified several African Americans SNPs that better define the association with QT and successfully narrowed intervals surrounding established loci. These results demonstrate that the same loci influence variation in QT across multiple populations, that novel signals exist in African Americans, and that the SNPs identified as strong candidates for functional evaluation implicate gene regulatory dysfunction in QT prolongation. PMID:22912591

Microsatellite Interruptions Stabilize Primate Genomes and Exist as Population-Specific Single Nucleotide Polymorphisms within Individual Human Genomes

PubMed Central

Ananda, Guruprasad; Hile, Suzanne E.; Breski, Amanda; Wang, Yanli; Kelkar, Yogeshwar; Makova, Kateryna D.; Eckert, Kristin A.

2014-01-01

Interruptions of microsatellite sequences impact genome evolution and can alter disease manifestation. However, human polymorphism levels at interrupted microsatellites (iMSs) are not known at a genome-wide scale, and the pathways for gaining interruptions are poorly understood. Using the 1000 Genomes Phase-1 variant call set, we interrogated mono-, di-, tri-, and tetranucleotide repeats up to 10 units in length. We detected ∼26,000–40,000 iMSs within each of four human population groups (African, European, East Asian, and American). We identified population-specific iMSs within exonic regions, and discovered that known disease-associated iMSs contain alleles present at differing frequencies among the populations. By analyzing longer microsatellites in primate genomes, we demonstrate that single interruptions result in a genome-wide average two- to six-fold reduction in microsatellite mutability, as compared with perfect microsatellites. Centrally located interruptions lowered mutability dramatically, by two to three orders of magnitude. Using a biochemical approach, we tested directly whether the mutability of a specific iMS is lower because of decreased DNA polymerase strand slippage errors. Modeling the adenomatous polyposis coli tumor suppressor gene sequence, we observed that a single base substitution interruption reduced strand slippage error rates five- to 50-fold, relative to a perfect repeat, during synthesis by DNA polymerases α, β, or η. Computationally, we demonstrate that iMSs arise primarily by base substitution mutations within individual human genomes. Our biochemical survey of human DNA polymerase α, β, δ, κ, and η error rates within certain microsatellites suggests that interruptions are created most frequently by low fidelity polymerases. Our combined computational and biochemical results demonstrate that iMSs are abundant in human genomes and are sources of population-specific genetic variation that may affect genome stability. The genome-wide identification of iMSs in human populations presented here has important implications for current models describing the impact of microsatellite polymorphisms on gene expression. PMID:25033203

Genome-wide association studies suggest that APOL1-environment interactions more likely trigger kidney disease in African Americans with nondiabetic nephropathy than strong APOL1-second gene interactions.

PubMed

Langefeld, Carl D; Comeau, Mary E; Ng, Maggie C Y; Guan, Meijian; Dimitrov, Latchezar; Mudgal, Poorva; Spainhour, Mitzie H; Julian, Bruce A; Edberg, Jeffrey C; Croker, Jennifer A; Divers, Jasmin; Hicks, Pamela J; Bowden, Donald W; Chan, Gary C; Ma, Lijun; Palmer, Nicholette D; Kimberly, Robert P; Freedman, Barry I

2018-06-06

African Americans carrying two apolipoprotein L1 gene (APOL1) renal risk variants have a high risk for nephropathy. However, only a minority develops end-stage renal disease (ESRD). Hence, modifying factors likely contribute to initiation of kidney disease such as endogenous (HIV infection) or exogenous (interferon treatment) environmental modifiers. In this report, genome-wide association studies and a meta-analysis were performed to identify novel loci for nondiabetic ESRD in African Americans and to detect genetic modifiers in APOL1-associated nephropathy. Two African American cohorts were analyzed, 1749 nondiabetic ESRD cases and 1136 controls from Wake Forest and 901 lupus nephritis (LN)-ESRD cases and 520 controls with systemic lupus erythematosus but lacking nephropathy from the LN-ESRD Consortium. Association analyses adjusting for APOL1 G1/G2 renal-risk variants were completed and stratified by APOL1 risk genotype status. Individual genome-wide association studies and meta-analysis results of all 2650 ESRD cases and 1656 controls did not detect significant genome-wide associations with ESRD beyond APOL1. Similarly, no single nucleotide polymorphism showed significant genome-wide evidence of an interaction with APOL1 risk variants. Thus, although variants with small individual effects cannot be ruled out and are likely to exist, our results suggest that APOL1-environment interactions may be of greater clinical importance in triggering nephropathy in African Americans than APOL1 interactions with other single nucleotide polymorphisms. Copyright © 2018 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

Chemokine gene polymorphisms associate with gender in patients with uveitis.

PubMed

Chen, Y; Vaughan, R W; Kondeatis, E; Fortune, F; Graham, E M; Stanford, M R; Wallace, G R

2004-01-01

Uveitis is an inflammatory condition of ocular tissue characterized by leukocyte infiltration, tissue damage, and decreased visual acuity. Chemokines have been implicated in the pathogenesis of uveitis. Polymorphisms in the genes encoding chemokines have been described as affecting chemokine production or function. We analyzed the frequency of single-nucleotide polymorphisms (SNPs) in genes encoding CCL2 (-2518 and -2076) and CCL5 (-403 and -28) in patients with Behçet's disease (BD), a systemic form of uveitis, and patients with retinal vasculitis (RV), an organ-specific form of disease. We report that there was no association between any SNP and disease. However, when segregated on the basis of gender the CCR5 -403 AA genotype was only found in male patients with BD. Similarly, CCL2 genotypes 1/2 were predominant in males, while genotype 4 was significantly associated with disease in female patients with BD. Differences in disease symptoms and severity between males and females have been described in BD and gender-specific genetic differences in chemokine gene function may be involved.

High prevalence of anaemia among African migrants in Germany persists after exclusion of iron deficiency and erythrocyte polymorphisms.

PubMed

Müller, Sophie A; Amoah, Stephen K B; Meese, Stefanie; Spranger, Joachim; Mockenhaupt, Frank P

2015-09-01

Haematological parameters differ between individuals of African and European ancestry. However, respective data of first-generation African migrants are virtually absent. We assessed these in Ghanaian migrants living in Berlin, compared them with reference data from Germany and Ghana, and estimated the role of iron deficiency (ID) and erythrocyte polymorphisms in anaemia. A total of 576 Ghanaians (median age, 45 years) were analysed. Blood counts were performed, haemoglobinopathies and glucose-6-phosphate dehydrogenase (G6PD) deficiency were genotyped, and concentrations of ferritin and C-reactive protein were measured to define ID. Most individuals had resided in Germany for more than a decade (median, 18 years). By WHO definition, anaemia was present in 30.9% of females and 9.4% of males. Median haemoglobin (Hb) levels were lower than among Germans (women, -0.8 g/dl, men, -0.7 g/dl). However, applying reference values from Ghana, only 1.9% of the migrants were considered anaemic. Alpha-thalassaemia, Hb variants and G6PD deficiency were observed in 33.9%, 28.3% and 23.6%, respectively. ID was highly prevalent in women (32.0%; men, 3.9%). The population fraction of anaemia cases attributable to ID was 29.0% (alpha-thalassaemia, 13.6%; G6PD deficiency, 13.5%). Nevertheless, excluding ID, alpha-thalassaemia, G6PD deficiency and sickle cell disease, anaemia prevalence remained high (women, 18.4%; men, 6.5%), and was also high when applying uncensored thresholds proposed for African Americans (females, 19.3%; males, 7.8%). Iron deficiency and erythrocyte polymorphisms are common among first-generation Ghanaian migrants but explain only part of the increased prevalence of anaemia. Common Hb thresholds for the definition of anaemia may not be appropriate for this group. © 2015 John Wiley & Sons Ltd.

A chronotype comparison of South African and Dutch marathon runners: The role of scheduled race start times and effects on performance.

PubMed

Henst, Rob H P; Jaspers, Richard T; Roden, Laura C; Rae, Dale E

2015-01-01

Recently, a high prevalence of morning-types was reported among trained South African endurance athletes. Proposed explanations for this observation were that either the chronotype of these athletes is better suited to coping with the early-morning start times of endurance events in South Africa; or habitual early waking for training or endurance events may have conditioned the athletes to adapt and become morning-types. The South African endurance athletes also had earlier chronotypes compared to a control population of less active individuals, suggesting that individuals who are more physically active may have earlier chronotypes. However, since both the South African athlete and control groups showed an overrepresentation of morning-types compared to European and American populations, the South African climate may in part have explained this bias towards morningness. Given the latitude and climate differences between South Africa and the Netherlands, and that South African marathons typically start at about 06:30 while those in the Netherlands start later (±11:00), comparison of South African and Dutch marathon runners and active controls would allow for simultaneous assessment of the effects of marathon start time, degree of physical activity and climate on chronotype. Therefore, the primary aims of this study were: (i) to assess the effect of marathon start time on chronotype in marathon runners and (ii) to determine the extent to which either degree of physical activity or climate might explain the bias towards morningness observed in South African athletes and controls. A secondary aim was to determine whether any relationships exist between chronotype, PERIOD3 (PER3) variable number tandem repeat (VNTR) polymorphism genotype, habitual training habits and marathon performance. Trained male marathon runners from South Africa (n = 95) and the Netherlands (n = 90), and active but non-competitive male controls from South Africa (n = 97) and the Netherlands (n = 98) completed a questionnaire capturing demographics, training and race history, as well as the Horne-Östberg morningness-eveningness personality questionnaire. All participants donated buccal cell samples from which genomic DNA was extracted and polymerase chain reaction analysis was used to genotype them for the PER3 VNTR polymorphism, which has previously been associated with chronotype. The main finding was that South African runners were significantly more morning-orientated than Dutch runners suggesting that participation in an endurance sport with an earlier start time may influence chronotype. Secondly, both the South African and Dutch runners were significantly more morning-orientated than their respective control groups, indicating that individuals who train for and participate in recreational endurance sport races have an earlier chronotype than physically active but non-competitive males. Thirdly, mean chronotype scores were similar between the South African and Dutch control groups, suggesting that climate does not seem to affect chronotype in these groups. Fourthly, the PER3 VNTR polymorphism distribution was similar between the four groups and was not associated with chronotype, suggesting that the difference in chronotype between the four groups in this study is not explained by the PER3 VNTR genotype. Lastly, in the South African runners group, a higher preference for mornings was associated with a better personal best half-marathon and current marathon performance.

Association of FCGR2A rs1801274 polymorphism with susceptibility to autoimmune diseases: A meta-analysis.

PubMed

Zhang, Chang'e; Wang, Wenju; Zhang, Hong'e; Wei, Lulu; Guo, Shuping

2016-06-28

The aim of this meta-analysis was to estimate the association between the FCGR2A rs1801274 polymorphism and the susceptibility to autoimmune diseases more precisely. A meta-analysis was conducted on the association between the FCGR2A gene variants and ADs by allelic contrast, homozygote contrast, the recessive model, and the dominant model. A total of 17 studies with 30 comparisons in different populations and genotype-methods were available for this meta-analysis, including 10 Kawasaki disease (KD), 7 Ulcerative colitis (UC), 6 Crohn's disease (CD), 3 Rheumatoid arthritis (RA), 2 Systemic lupus erythematosus (SLE), 1 Autoimmune thyroid disease (ATD) and 1 diabetes mellitus type 1 (T1D). A significant association between FCGR2A rs1801274 polymorphism were found in KD (OR = 1.409, P < 0.001) and UC (OR = 1.237, P < 0.001). A overall meta-analysis increased risk of AD significant association between FCGR2A rs1801274 gene polymorphism and ADs under allelic (OR = 1.378, P=0.000), homozygous (OR: 1.866, P=0.001), dominant (OR = 1.667, P = 0.000) and recessive (OR = 1.434, P=0.000) in Asian population. Meanwhile, a decreased risk of AD was detected in the allelic (OR= 0.882, P = 0.011), homozygous (OR = 0.777, P = 0.013), dominant (OR = 0.850, P = 0.032) and recessive (OR = 0.840, P = 0.048) in African-American population. This meta-analysis demonstrates that the FCGR2A rs1801274 G-allele confers susceptibility to KD and UC. Data also suggests that the FCGR2A rs1801274 polymorphism may be associated with the susceptibility of multiple ADs in Asian and African-American populations.

Association of FCGR2A rs1801274 polymorphism with susceptibility to autoimmune diseases: A meta-analysis

PubMed Central

Wei, Lulu; Guo, Shuping

2016-01-01

Objectives The aim of this meta-analysis was to estimate the association between the FCGR2A rs1801274 polymorphism and the susceptibility to autoimmune diseases more precisely. Methods A meta-analysis was conducted on the association between the FCGR2A gene variants and ADs by allelic contrast, homozygote contrast, the recessive model, and the dominant model. Results A total of 17 studies with 30 comparisons in different populations and genotype-methods were available for this meta-analysis, including 10 Kawasaki disease (KD), 7 Ulcerative colitis (UC), 6 Crohn's disease (CD), 3 Rheumatoid arthritis (RA), 2 Systemic lupus erythematosus (SLE), 1 Autoimmune thyroid disease (ATD) and 1 diabetes mellitus type 1 (T1D). A significant association between FCGR2A rs1801274 polymorphism were found in KD (OR = 1.409, P < 0.001) and UC (OR = 1.237, P < 0.001). A overall meta-analysis increased risk of AD significant association between FCGR2A rs1801274 gene polymorphism and ADs under allelic (OR = 1.378, P=0.000), homozygous (OR: 1.866, P=0.001), dominant (OR = 1.667, P = 0.000) and recessive (OR = 1.434, P=0.000) in Asian population. Meanwhile, a decreased risk of AD was detected in the allelic (OR= 0.882, P = 0.011), homozygous (OR = 0.777, P = 0.013), dominant (OR = 0.850, P = 0.032) and recessive (OR = 0.840, P = 0.048) in African-American population. Conclusions This meta-analysis demonstrates that the FCGR2A rs1801274 G-allele confers susceptibility to KD and UC. Data also suggests that the FCGR2A rs1801274 polymorphism may be associated with the susceptibility of multiple ADs in Asian and African-American populations. PMID:27270653

Triosephosphate isomerase gene promoter variation: -5G/A and -8G/A polymorphisms in clinical malaria groups in two African populations.

PubMed

Guerra, Mónica; Machado, Patrícia; Manco, Licínio; Fernandes, Natércia; Miranda, Juliana; Arez, Ana Paula

2015-06-01

TPI1 promoter polymorphisms occur in high prevalence in individuals from African origin. Malaria-patients from Angola and Mozambique were screened for the TPI1 gene promoter variants rs1800200A>G, (-5G>A), rs1800201G>A, (-8G>A), rs1800202T>G, (-24T>G), and for the intron 5 polymorphism rs2071069G>A, (2262G>A). -5G>A and -8G>A variants occur in 47% and 53% in Angola and Mozambique, respectively while -24T>G was monomorphic for the wild-type T allele. Six haplotypes were identified and -8A occurred in 45% of the individuals, especially associated with the GAG haplotype and more frequent in non-severe malaria groups, although not significantly. The arising and dispersion of -5G>A and -8G>A polymorphisms is controversial. Their age was estimated by analyses of two microsatellite loci, CD4 and ATN1, adjacent to TPI1 gene. The -5G>A is older than -8G>A, with an average estimate of approximately 35,000 years. The -8A variant arose in two different backgrounds, suggesting independent mutational events. The first, on the -5G background, may have occurred in East Africa around 20,800 years ago; the second, on the -5A background, may have occurred in West Africa some 7500 years ago. These estimates are within the period of spread of agriculture and the malaria mosquito vector in Africa, which could has been a possible reason for the selection of -8A polymorphism in malaria endemic countries. Copyright © 2015 Elsevier B.V. All rights reserved.

Anxiety, Alexithymia, and Depression as Mediators of the Association between Childhood Abuse and Eating Disordered Behavior in African American and European American Women

ERIC Educational Resources Information Center

Mazzeo, Suzanne E.; Mitchell, Karen S.; Williams, Larry J.

2008-01-01

This study evaluated structural equation models of the associations among family functioning, childhood abuse, depression, anxiety, alexithymia, and eating disorder symptomatology in a sample of 412 European American and 192 African American female undergraduates. Additionally, the specific roles of anxiety, depression, and alexithymia as…

Gender-specific association of functional prodynorphin 68 bp repeats with cannabis exposure in an African American cohort.

PubMed

Yuferov, Vadim; Butelman, Eduardo R; Kreek, Mary Jeanne

2018-01-01

Cannabis use disorders (CUDs) cause substantial neuropsychiatric morbidity and comorbidity. There is evidence for gender-based differences in CUDs, for instance, a greater prevalence in males than in females. The main active component of cannabis is delta 9-tetrahydrocannabinol (delta 9-THC), a partial agonist of the cannabinoid type 1 receptor. Preclinical studies show that genetic or pharmacological manipulation of the kappa opioid receptor/dynorphin system modulates the effects of delta 9-THC. In this case-control study of adult African Americans (n=476; 206 females, 270 males), we examined the association of the functional prodynorphin 68 bp ( PDYN 68 bp) promoter repeats with categorical diagnoses of cannabis dependence ( Diagnostic and Statistical Manual of Mental Disorders-IV criteria), as well as with a rapid dimensional measure of maximum lifetime cannabis exposure (the Kreek-McHugh-Schluger-Kellogg cannabis scale). The PDYN 68 bp genotype (examined as short-short [SS], short-long [SL], or long-long [LL], based on the number of repeats) was not significantly associated with categorical cannabis-dependence diagnoses, either in males or in females. However, in males, the PDYN 68 bp SS+SL genotype was associated with both greater odds of any use of cannabis ( p <0.05) and earlier age of first cannabis use, compared to the LL genotype (ie, 15 versus 16.5 years of age; p <0.045). Males in the SS+SL group also had greater odds of high lifetime exposure to cannabis, compared to the LL group ( p <0.045). Of interest, none of the aforementioned genetic associations were significant in females. This study provides the first data on how the PDYN 68 bp genotype is associated with gender-specific patterns of exposure to cannabis. Overall, this study shows that PDYN 68 bp polymorphisms affect behaviors involved in early stages of nonmedical cannabis use and potentially lead to increasing self-exposure. These data may eventually lead to improvements in personalized medicine for the prevention and treatment of highly prevalent CUDs and neuropsychiatric comorbidities.

Gender-specific association of functional prodynorphin 68 bp repeats with cannabis exposure in an African American cohort

PubMed Central

Kreek, Mary Jeanne

2018-01-01

Background Cannabis use disorders (CUDs) cause substantial neuropsychiatric morbidity and comorbidity. There is evidence for gender-based differences in CUDs, for instance, a greater prevalence in males than in females. The main active component of cannabis is delta 9-tetrahydrocannabinol (delta 9-THC), a partial agonist of the cannabinoid type 1 receptor. Preclinical studies show that genetic or pharmacological manipulation of the kappa opioid receptor/dynorphin system modulates the effects of delta 9-THC. Methods In this case-control study of adult African Americans (n=476; 206 females, 270 males), we examined the association of the functional prodynorphin 68 bp (PDYN 68 bp) promoter repeats with categorical diagnoses of cannabis dependence (Diagnostic and Statistical Manual of Mental Disorders-IV criteria), as well as with a rapid dimensional measure of maximum lifetime cannabis exposure (the Kreek–McHugh–Schluger–Kellogg cannabis scale). Results The PDYN 68 bp genotype (examined as short–short [SS], short–long [SL], or long–long [LL], based on the number of repeats) was not significantly associated with categorical cannabis-dependence diagnoses, either in males or in females. However, in males, the PDYN 68 bp SS+SL genotype was associated with both greater odds of any use of cannabis (p<0.05) and earlier age of first cannabis use, compared to the LL genotype (ie, 15 versus 16.5 years of age; p<0.045). Males in the SS+SL group also had greater odds of high lifetime exposure to cannabis, compared to the LL group (p<0.045). Of interest, none of the aforementioned genetic associations were significant in females. Conclusion This study provides the first data on how the PDYN 68 bp genotype is associated with gender-specific patterns of exposure to cannabis. Overall, this study shows that PDYN 68 bp polymorphisms affect behaviors involved in early stages of nonmedical cannabis use and potentially lead to increasing self-exposure. These data may eventually lead to improvements in personalized medicine for the prevention and treatment of highly prevalent CUDs and neuropsychiatric comorbidities. PMID:29713172

Human immunodeficiency virus type 1 seroprevalence and antiretroviral drug resistance-associated mutations in miners in Gabon, central Africa.

PubMed

Caron, Mélanie; Makuwa, Maria; Souquière, Sandrine; Descamps, Diane; Brun-Vézinet, Françoise; Kazanji, Mirdad

2008-09-01

Miners in sub-Saharan African are known to have an extremely high prevalence of HIV-1 infection. We therefore evaluated the prevalence of HIV-1 infection among manganese miners in Gabon, central Africa and examined the diversity of HIV-1 strains by characterizing the polymorphism of the pol gene in order to observe drug resistance-associated mutations. In 857 samples tested, the HIV-1 prevalence was 2.9%. By pol sequence analysis, we showed that all the HIV-1 strains belonged to group M, with a majority of CRF02_AG (57%) followed by subtype A (9%) and CRF01_AE or subtype B (4%). The remaining HIV-1 strains demonstrated discordant genomic results and exhibited a mosaic pol genome (30%). Most of the mutations detected in pol coding regions corresponded to the subtype polymorphism, with no specific antiretroviral drug resistance. To avoid the rapid emergence of resistant viruses in this part of central Africa, continuous surveillance of the circulation of drug-resistant viruses must be maintained to guide treatment strategies.

Identification of the Kna/Knb polymorphism and a method for Knops genotyping

PubMed Central

Moulds, J.M.; Thomas, B.J.; Doumbo, O.; Diallo, D.A.; Lyke, K.E.; Plowe, C.V.; Rowe, J.A.; Birmingham, D.J.

2010-01-01

BACKGROUND: DNA mutations resulting in the McCoy and Swain-Langley polymorphisms have been identified on complement receptor 1 (CR1)—a ligand for rosetting of Plasmodium falciparum-infected RBCs. The molecular identification of the Kna/Knb polymorphism was sought to develop a genotyping method for use in the study of the Knops blood group and malaria. STUDY DESIGN AND METHODS: CR1 deletion constructs were used in inhibition studies of anti-Kna. PCR amplification of Exon 29 was followed by DNA sequencing. A PCR-RFLP was developed with NdeI, BsmI, and MfeI for the detection of Kna/Knb, McCa/McCb, and Sl1/Sl2, respectively. Knops phenotypes were determined with standard serologic techniques. RESULTS: A total of 310 Malian persons were phenotyped for Kna with 200 (64%) Kn(a+) and 110 (36%) Kn(a−). Many of the Kn(a−) exhibited the Knops-null phenotype, that is, Helgeson. The Kna/b DNA polymorphism was identified as a V1561M mutation with allele frequencies of Kna (V1561) 0.9 and Knb (M1561) 0.1. CONCLUSION: The high frequency (18%) of Knb in West African persons suggests that it is not solely a Caucasian trait. Furthermore, because of the high incidence of heterozygosity as well as amorphs, accurate Knops typing of donors of African descent is best accomplished by a combination of molecular and serologic techniques. PMID:14962306

Species-Specific Variation in RELA Underlies Differences in NF-κB Activity: a Potential Role in African Swine Fever Pathogenesis▿

PubMed Central

Palgrave, Christopher J.; Gilmour, Linzi; Lowden, C. Stewart; Lillico, Simon G.; Mellencamp, Martha A.; Whitelaw, C. Bruce A.

2011-01-01

African swine fever virus (ASFV) is a highly infectious disease of domestic pigs, with virulent isolates causing a rapidly fatal hemorrhagic fever. In contrast, the porcine species endogenous to Africa tolerate infection. The ability of the virus to persist in one host while killing another genetically related host implies that disease severity may be, in part, modulated by host genetic variation. To complement transcription profiling approaches to identify the underlying genetic variation in the host response to ASFV, we have taken a candidate gene approach based on known signaling pathways that interact with the virus-encoded immunomodulatory protein A238L. We report the sequencing of these genes from different pig species and the identification and initial in vitro characterization of polymorphic variation in RELA (p65; v-rel reticuloendotheliosis viral oncogene homolog A), the major component of the NF-κB transcription factor. Warthog RELA and domestic pig RELA differ at three amino acids. Transient cell transfection assays indicate that this variation is reflected in reduced NF-κB activity in vitro for warthog RELA but not for domestic pig RELA. Induction assays indicate that warthog RELA and domestic pig RELA are elevated essentially to the same extent. Finally, mutational studies indicate that the S531P site conveys the majority of the functional variation between warthog RELA and domestic pig RELA. We propose that the variation in RELA identified between the warthog and domestic pig has the potential to underlie the difference between tolerance and rapid death upon ASFV infection. PMID:21450812

Racial discrimination and relationship functioning among African American couples.

PubMed

Lavner, Justin A; Barton, Allen W; Bryant, Chalandra M; Beach, Steven R H

2018-05-21

Racial discrimination is a common stressor for African Americans, with negative consequences for mental and physical well-being. It is likely that these effects extend into the family, but little research has examined the association between racial discrimination and couple functioning. This study used dyadic data from 344 rural, predominantly low-income heterosexual African American couples with an early adolescent child to examine associations between self-reported racial discrimination, psychological and physical aggression, and relationship satisfaction and instability. Experiences of discrimination were common among men and women and were negatively associated with relationship functioning. Specifically, men reported higher levels of psychological aggression and relationship instability if they experienced higher levels of racial discrimination, and women reported higher levels of physical aggression if they experienced higher levels of racial discrimination. All results replicated when controlling for financial hardship, indicating unique effects for discrimination. Findings suggest that racial discrimination may be negatively associated with relationship functioning among African Americans and call for further research on the processes underlying these associations and their long-term consequences. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Origin of honeybees (Apis mellifera L.) from the Yucatan peninsula inferred from mitochondrial DNA analysis.

PubMed

Clarke, K E; Oldroyd, B P; Javier, J; Quezada-Euán, G; Rinderer, T E

2001-06-01

Honeybees (Apis mellifera L.) sampled at sites in Europe, Africa and South America were analysed using a mitochondrial DNA restriction fragment length polymorphism (RFLP) marker. These samples were used to provide baseline information for a detailed analysis of the process of Africanization of bees from the neotropical Yucatan peninsula of Mexico. Radical changes in mitochondrial haplotype (mitotype) frequencies were found to have occurred in the 13-year period studied. Prior to the arrival of Africanized bees (1986) the original inhabitants of the Yucatan peninsula appear to have been essentially of southeastern European origin with a smaller proportion having northwestern European ancestry. Three years after the migration of Africanized bees into the area (1989), only very low levels of maternal gene flow from Africanized populations into the resident European populations had occurred. By 1998, however, there was a sizeable increase in the proportion of African mitotypes in domestic populations (61%) with feral populations having 87% of mitotypes classified as African derived. The results suggest that the early stages of Africanization did not involve a rapid replacement of European with African mitotypes and that earlier studies probably overestimated the prevalence of African mitotypes.

A preliminary study: novelty seeking, frontal executive function, and dopamine receptor (D2) TaqI A gene polymorphism in patients with methamphetamine dependence.

PubMed

Han, Doug Hyun; Yoon, Sujung J; Sung, Young Hoon; Lee, Young Sik; Kee, Baik Seok; Lyoo, In Kyoon; Renshaw, Perry F; Cho, Soo Churl

2008-01-01

Dopamine receptor polymorphisms have been associated with specific patterns of novelty seeking (NS) temperamental nature and frontal executive function. In addition, carriers of dopamine receptor type 2 (DRD2)-TaqI A1 have been hypothesized to be potentially vulnerable to addictive behaviors. In the present study, the association between dopamine D2 polymorphisms, NS, and frontal executive function was studied. Thirty-seven methamphetamine (MA)-dependent subjects and 40 healthy comparison subjects participated in the current study. The severity of addiction, NS temperament, and frontal executive functions were measured using the Addiction Severity Index, the NS subscale in the Temperament and Character Inventory, and the Wisconsin Card Sorting Test, respectively. All subjects were genotyped with regard to DRD2-TaqI polymorphisms. The prevalence of DRD2-TaqI A1 allele polymorphisms was greater in the MA-abuser group than in the comparison group. Patients with MA dependence also had higher NS characteristics and high scores in total trials, errors, and perseverative errors of the Wisconsin Card Sorting Test than comparison subjects. Within patients with MA dependence, the subgroup of DRD2-TaqI A1 carrier had greater NS scores relative to those without, whereas there was only a trend level of lower frontal executive function in the first subgroup. In the present study, the MA-dependent patients with DRD2-TaqI A1 allele had significantly greater NS scores and lower frontal executive function with a trend level than those without. These preliminary results suggest that MA-dependent patients may have the possibility of genetic and biogenic vulnerability to MA.

DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuhki, Naoya; O'Brien, S.J.

1990-01-01

The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. The authors present here a quantitative analysis of restriction fragmentmore » length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations.« less

DNA variation of the mammalian major histocompatibility complex reflects genomic diversity and population history.

PubMed Central

Yuhki, N; O'Brien, S J

1990-01-01

The major histocompatibility complex (MHC) is a multigene complex of tightly linked homologous genes that encode cell surface antigens that play a key role in immune regulation and response to foreign antigens. In most species, MHC gene products display extreme antigenic polymorphism, and their variability has been interpreted to reflect an adaptive strategy for accommodating rapidly evolving infectious agents that periodically afflict natural populations. Determination of the extent of MHC variation has been limited to populations in which skin grafting is feasible or for which serological reagents have been developed. We present here a quantitative analysis of restriction fragment length polymorphism of MHC class I genes in several mammalian species (cats, rodents, humans) known to have very different levels of genetic diversity based on functional MHC assays and on allozyme surveys. When homologous class I probes were employed, a notable concordance was observed between the extent of MHC restriction fragment variation and functional MHC variation detected by skin grafts or genome-wide diversity estimated by allozyme screens. These results confirm the genetically depauperate character of the African cheetah, Acinonyx jubatus, and the Asiatic lion, Panthera leo persica; further, they support the use of class I MHC molecular reagents in estimating the extent and character of genetic diversity in natural populations. Images PMID:1967831

Replication and functional genomic analyses of the breast cancer susceptibility locus at 6q25.1 generalize its importance in women of Chinese, Japanese and European ancestry

PubMed Central

Cai, Qiuyin; Wen, Wanqing; Qu, Shimian; Li, Guoliang; Egan, Kathleen M.; Chen, Kexin; Deming, Sandra L; Shen, Hongbing; Shen, Chen-Yang; Gammon, Marilie D.; Blot, William J.; Matsuo, Keitaro; Haiman, Christopher A.; Khoo, Ui Soon; Iwasaki, Motoki; Santella, Regina M.; Zhang, Lina; Fair, Alecia Malin; Hu, Zhibin; Wu, Pei-Ei; Signorello, Lisa B.; Titus-Ernstoff, Linda; Tajima, Kazuo; Henderson, Brian E.; Chan, Kelvin Y.K.; Kasuga, Yoshio; Newcomb, Polly A.; Zheng, Hong; Cui, Yong; Wang, Furu; Shieh, Ya-Lan; Iwata, Hiroji; Le Marchand, Loic; Chan, Sum Yin; Shrubsole, Martha J.; Trentham-Dietz, Amy; Tsugane, Shoichiro; Garcia-Closas, Montserrat; Long, Jirong; Li, Chun; Shi, Jiajun; Huang, Bo; Xiang, Yong-Bing; Gao, Yu-Tang; Lu, Wei; Shu, Xiao-Ou; Zheng, Wei

2011-01-01

We evaluated the generalizability of a single nucleotide polymorphism (SNP), rs2046210 (A/G allele), associated with breast cancer risk that was initially identified at 6q25.1 in a genome-wide association study conducted among Chinese women. In a pooled analysis of over 31,000 women of East-Asian, European, and African ancestry, we found a positive association for rs2046210 and breast cancer risk in Chinese women [ORs (95%CI)=1.30(1.22–1.38) and 1.64(1.50–1.80) for the AG and AA genotypes, respectively, P for trend = 1.54 × 10−30], Japanese women [ORs (95%CI)=1.31(1.13–1.52) and 1.37(1.06–1.76), P for trend = 2.51 × 10−4], and European-ancestry American women [ORs (95%CI)=1.07(0.99–1.16) and 1.18(1.04–1.34), P for trend = 0.0069]. No association with this SNP, however, was observed in African American women [ORs (95%CI)=0.81(0.63–1.06) and 0.85(0.65–1.11) for the AG and AA genotypes, respectively, P for trend = 0.4027). In vitro functional genomic studies identified a putative functional variant, rs6913578. This SNP is 1,440 bp downstream of rs2046210 and is in high LD with rs2046210 in Chinese (r2=0.91) and European-ancestry (r2=0.83) populations, but not in Africans (r2=0.57). SNP rs6913578 was found to be associated with breast cancer risk in Chinese and European-ancestry American women. After adjusting for rs2046210, the association of rs6913578 with breast cancer risk in African Americans approached borderline significance. Results from this large consortium study confirmed the association of rs2046210 with breast cancer risk among women of Chinese, Japanese, and European ancestry. This association may be explained in part by a putatively functional variant (rs6913578) identified in the region. PMID:21303983

Replication and functional genomic analyses of the breast cancer susceptibility locus at 6q25.1 generalize its importance in women of chinese, Japanese, and European ancestry.

PubMed

Cai, Qiuyin; Wen, Wanqing; Qu, Shimian; Li, Guoliang; Egan, Kathleen M; Chen, Kexin; Deming, Sandra L; Shen, Hongbing; Shen, Chen-Yang; Gammon, Marilie D; Blot, William J; Matsuo, Keitaro; Haiman, Christopher A; Khoo, Ui Soon; Iwasaki, Motoki; Santella, Regina M; Zhang, Lina; Fair, Alecia Malin; Hu, Zhibin; Wu, Pei-Ei; Signorello, Lisa B; Titus-Ernstoff, Linda; Tajima, Kazuo; Henderson, Brian E; Chan, Kelvin Y K; Kasuga, Yoshio; Newcomb, Polly A; Zheng, Hong; Cui, Yong; Wang, Furu; Shieh, Ya-Lan; Iwata, Hiroji; Le Marchand, Loic; Chan, Sum Yin; Shrubsole, Martha J; Trentham-Dietz, Amy; Tsugane, Shoichiro; Garcia-Closas, Montserrat; Long, Jirong; Li, Chun; Shi, Jiajun; Huang, Bo; Xiang, Yong-Bing; Gao, Yu-Tang; Lu, Wei; Shu, Xiao-Ou; Zheng, Wei

2011-02-15

We evaluated the generalizability of a single nucleotide polymorphism (SNP), rs2046210 (A/G allele), associated with breast cancer risk that was initially identified at 6q25.1 in a genome-wide association study conducted among Chinese women. In a pooled analysis of more than 31,000 women of East-Asian, European, and African ancestry, we found a positive association for rs2046210 and breast cancer risk in Chinese women [ORs (95% CI) = 1.30 (1.22-1.38) and 1.64 (1.50-1.80) for the AG and AA genotypes, respectively, P for trend = 1.54 × 10⁻³⁰], Japanese women [ORs (95% CI) = 1.31 (1.13-1.52) and 1.37 (1.06-1.76), P for trend = 2.51 × 10⁻⁴], and European-ancestry American women [ORs (95% CI) = 1.07 (0.99-1.16) and 1.18 (1.04-1.34), P for trend = 0.0069]. No association with this SNP, however, was observed in African American women [ORs (95% CI) = 0.81 (0.63-1.06) and 0.85 (0.65-1.11) for the AG and AA genotypes, respectively, P for trend = 0.4027]. In vitro functional genomic studies identified a putative functional variant, rs6913578. This SNP is 1,440 bp downstream of rs2046210 and is in high linkage disequilibrium with rs2046210 in Chinese (r(2) = 0.91) and European-ancestry (r² = 0.83) populations, but not in Africans (r² = 0.57). SNP rs6913578 was found to be associated with breast cancer risk in Chinese and European-ancestry American women. After adjusting for rs2046210, the association of rs6913578 with breast cancer risk in African Americans approached borderline significance. Results from this large consortium study confirmed the association of rs2046210 with breast cancer risk among women of Chinese, Japanese, and European ancestry. This association may be explained in part by a putatively functional variant (rs6913578) identified in the region. ©2011 AACR.

Red Blood Cell Polymorphism and Susceptibility to Plasmodium vivax

PubMed Central

Zimmerman, Peter A.; Ferreira, Marcelo U.; Howes, Rosalind E.; Mercereau-Puijalon, Odile

2013-01-01

Resistance to Plasmodium vivax blood-stage infection has been widely recognised to result from absence of the Duffy (Fy) blood group from the surface of red blood cells (RBCs) in individuals of African descent. Interestingly, recent studies from different malaria-endemic regions have begun to reveal new perspectives on the association between Duffy gene polymorphism and P. vivax malaria. In Papua New Guinea and the Americas, heterozygous carriers of a Duffy-negative allele are less susceptible to P. vivax infection than Duffy-positive homozygotes. In Brazil, studies show that the Fya antigen, compared to Fyb, is associated with lower binding to the P. vivax Duffy-binding protein and reduced susceptibility to vivax malaria. Additionally, it is interesting that numerous studies have now shown that P. vivax can infect RBCs and cause clinical disease in Duffy-negative people. This suggests that the relationship between P. vivax and the Duffy antigen is more complex than customarily described. Evidence of P. vivax Duffy-independent red cell invasion indicates that the parasite must be evolving alternative red cell invasion pathways. In this chapter, we review the evidence for P. vivax Duffy-dependent and Duffy-independent red cell invasion. We also consider the influence of further host gene polymorphism associated with malaria endemicity on susceptibility to vivax malaria. The interaction between the parasite and the RBC has significant potential to influence the effectiveness of P. vivax-specific vaccines and drug treatments. Ultimately, the relationships between red cell polymorphisms and P. vivax blood-stage infection will influence our estimates on the population at risk and efforts to eliminate vivax malaria. PMID:23384621

Genome-wide Association Study of Cannabis Dependence Severity, Novel Risk Variants, and Shared Genetic Risks.

PubMed

Sherva, Richard; Wang, Qian; Kranzler, Henry; Zhao, Hongyu; Koesterer, Ryan; Herman, Aryeh; Farrer, Lindsay A; Gelernter, Joel

2016-05-01

Cannabis dependence (CAD) is a serious problem worldwide and is of growing importance in the United States because cannabis is increasingly available legally. Although genetic factors contribute substantially to CAD risk, at present no well-established specific genetic risk factors for CAD have been elucidated. To report findings for DSM-IV CAD criteria from association analyses performed in large cohorts of African American and European American participants from 3 studies of substance use disorder genetics. This genome-wide association study for DSM-IV CAD criterion count was performed in 3 independent substance dependence cohorts (the Yale-Penn Study, Study of Addiction: Genetics and Environment [SAGE], and International Consortium on the Genetics of Heroin Dependence [ICGHD]). A referral sample and volunteers recruited in the community and from substance abuse treatment centers included 6000 African American and 8754 European American participants, including some from small families. Participants from the Yale-Penn Study were recruited from 2000 to 2013. Data were collected for the SAGE trial from 1990 to 2007 and for the ICGHD from 2004 to 2009. Data were analyzed from January 2, 2013, to November 9, 2015. Criterion count for DSM-IV CAD. Among the 14 754 participants, 7879 were male, 6875 were female, and the mean (SD) age was 39.2 (10.2) years. Three independent regions with genome-wide significant single-nucleotide polymorphism associations were identified, considering the largest possible sample. These included rs143244591 (β = 0.54, P = 4.32 × 10-10 for the meta-analysis) in novel antisense transcript RP11-206M11.7;rs146091982 (β = 0.54, P = 1.33 × 10-9 for the meta-analysis) in the solute carrier family 35 member G1 gene (SLC35G1); and rs77378271 (β = 0.29, P = 2.13 × 10-8 for the meta-analysis) in the CUB and Sushi multiple domains 1 gene (CSMD1). Also noted was evidence of genome-level pleiotropy between CAD and major depressive disorder and for an association with single-nucleotide polymorphisms in genes associated with schizophrenia risk. Several of the genes identified have functions related to neuronal calcium homeostasis or central nervous system development. These results are the first, to our knowledge, to identify specific CAD risk alleles and potential genetic factors contributing to the comorbidity of CAD with major depression and schizophrenia.

Diversity in the Toll-Like Receptor Genes of the African Penguin (Spheniscus demersus).

PubMed

Dalton, Desiré Lee; Vermaak, Elaine; Roelofse, Marli; Kotze, Antoinette

2016-01-01

The African penguin, Spheniscus demersus, is listed as Endangered by the IUCN Red List of Threatened Species due to the drastic reduction in population numbers over the last 20 years. To date, the only studies on immunogenetic variation in penguins have been conducted on the major histocompatibility complex (MHC) genes. It was shown in humans that up to half of the genetic variability in immune responses to pathogens are located in non-MHC genes. Toll-like receptors (TLRs) are now increasingly being studied in a variety of taxa as a broader approach to determine functional genetic diversity. In this study, we confirm low genetic diversity in the innate immune region of African penguins similar to that observed in New Zealand robin that has undergone several severe population bottlenecks. Single nucleotide polymorphism (SNP) diversity across TLRs varied between ex situ and in situ penguins with the number of non-synonymous alterations in ex situ populations (n = 14) being reduced in comparison to in situ populations (n = 16). Maintaining adaptive diversity is of vital importance in the assurance populations as these animals may potentially be used in the future for re-introductions. Therefore, this study provides essential data on immune gene diversity in penguins and will assist in providing an additional monitoring tool for African penguin in the wild, as well as to monitor diversity in ex situ populations and to ensure that diversity found in the in situ populations are captured in the assurance populations.

LRP5 coding polymorphisms influence the variation of peak bone mass in a normal population of French-Canadian women.

PubMed

Giroux, Sylvie; Elfassihi, Latifa; Cardinal, Guy; Laflamme, Nathalie; Rousseau, François

2007-05-01

Bone mineral density has a strong genetic component but it is also influenced by environmental factors making it a complex trait to study. LRP5 gene was previously shown to be involved in rare diseases affecting bone mass. Mutations associated with gain-of-function were described as well as loss-of-function mutations. Following this discovery, many frequent LRP5 polymorphisms were tested against the variation of BMD in the normal population. Heel bone parameters (SOS, BUA) were measured by right calcaneal QUS in 5021 healthy French-Canadian women and for 2104 women, BMD evaluated by DXA at two sites was available (femoral neck (FN) and lumbar spine (LS)). Among women with QUS measures and those with DXA measures, 26.5% and 32.8% respectively were premenopausal, 9.2% and 10.7% were perimenopausal and 64.2% and 56.5% were postmenopausal. About a third of the peri- and postmenopausal women never received hormone therapy. Two single nucleotide coding polymorphisms (Val667Met and Ala1330Val) in LRP5 gene were genotyped by allele-specific PCR. All bone measures were tested individually for associations with each polymorphism by analysis of covariance with adjustment for non genetic risk factors. Furthermore, haplotype analysis was performed to take into account the strong linkage disequilibrium between the two polymorphisms. The two LRP5 polymorphisms were found to be associated with all five bone measures (L2L4 and femoral neck DXA as well as heel SOS, BUA and stiffness index) in the whole sample. Premenopausal women drove the association as expected from the proposed role of LRP5 in peak bone mass. Our results suggest that the Val667Met polymorphism is the causative variant but this remains to be functionally proven.

The CHRNA5-CHRNA3-CHRNB4 nicotinic receptor subunit gene cluster affects risk for nicotine dependence in African-Americans and in European-Americans.

PubMed

Saccone, Nancy L; Wang, Jen C; Breslau, Naomi; Johnson, Eric O; Hatsukami, Dorothy; Saccone, Scott F; Grucza, Richard A; Sun, Lingwei; Duan, Weimin; Budde, John; Culverhouse, Robert C; Fox, Louis; Hinrichs, Anthony L; Steinbach, Joseph Henry; Wu, Meng; Rice, John P; Goate, Alison M; Bierut, Laura J

2009-09-01

Genetic association studies have shown the importance of variants in the CHRNA5-CHRNA3-CHRNB4 cholinergic nicotinic receptor subunit gene cluster on chromosome 15q24-25.1 for the risk of nicotine dependence, smoking, and lung cancer in populations of European descent. We have carried out a detailed study of this region using dense genotyping in both European-Americans and African-Americans. We genotyped 75 known single nucleotide polymorphisms (SNPs) and one sequencing-discovered SNP in an African-American sample (N = 710) and in a European-American sample (N = 2,062). Cases were nicotine-dependent and controls were nondependent smokers. The nonsynonymous CHRNA5 SNP rs16969968 is the most significant SNP associated with nicotine dependence in the full sample of 2,772 subjects [P = 4.49 x 10(-8); odds ratio (OR), 1.42; 95% confidence interval (CI), 1.25-1.61] as well as in African-Americans only (P = 0.015; OR, 2.04; 1.15-3.62) and in European-Americans only (P = 4.14 x 10(-7); OR, 1.40; 1.23-1.59). Other SNPs that have been shown to affect the mRNA levels of CHRNA5 in European-Americans are associated with nicotine dependence in African-Americans but not in European-Americans. The CHRNA3 SNP rs578776, which has a low correlation with rs16969968, is associated with nicotine dependence in European-Americans but not in African-Americans. Less common SNPs (frequency

Generalization of Associations of Kidney-Related Genetic Loci to American Indians

PubMed Central

Haack, Karin; Almasy, Laura; Laston, Sandra; Lee, Elisa T.; Best, Lyle G.; Fabsitz, Richard R.; MacCluer, Jean W.; Howard, Barbara V.; Umans, Jason G.; Cole, Shelley A.

2014-01-01

Summary Background and objectives CKD disproportionally affects American Indians, who similar to other populations, show genetic susceptibility to kidney outcomes. Recent studies have identified several loci associated with kidney traits, but their relevance in American Indians is unknown. Design, setting, participants, & measurements This study used data from a large, family-based genetic study of American Indians (the Strong Heart Family Study), which includes 94 multigenerational families enrolled from communities located in Oklahoma, the Dakotas, and Arizona. Individuals were recruited from the Strong Heart Study, a population-based study of cardiovascular disease in American Indians. This study selected 25 single nucleotide polymorphisms in 23 loci identified from recently published kidney-related genome-wide association studies in individuals of European ancestry to evaluate their associations with kidney function (estimated GFR; individuals 18 years or older, up to 3282 individuals) and albuminuria (urinary albumin to creatinine ratio; n=3552) in the Strong Heart Family Study. This study also examined the association of single nucleotide polymorphisms in the APOL1 region with estimated GFR in 1121 Strong Heart Family Study participants. GFR was estimated using the abbreviated Modification of Diet in Renal Disease Equation. Additive genetic models adjusted for age and sex were used. Results This study identified significant associations of single nucleotide polymorphisms with estimated GFR in or nearby PRKAG2, SLC6A13, UBE2Q2, PIP5K1B, and WDR72 (P<2.1 × 10-3 to account for multiple testing). Single nucleotide polymorphisms in these loci explained 2.2% of the estimated GFR total variance and 2.9% of its heritability. An intronic variant of BCAS3 was significantly associated with urinary albumin to creatinine ratio. APOL1 single nucleotide polymorphisms were not associated with estimated GFR in a single variant test or haplotype analyses, and the at-risk variants identified in individuals with African ancestry were not detected in DNA sequencing of American Indians. Conclusion This study extends the genetic associations of loci affecting kidney function to American Indians, a population at high risk of kidney disease, and provides additional support for a potential biologic relevance of these loci across ancestries. PMID:24311711

Cytokine gene polymorphisms and atopic disease in two European cohorts. (ECRHS-Basel and SAPALDIA)

PubMed Central

Imboden, M; Nieters, A; Bircher, AJ; Brutsche, M; Becker, N; Wjst, M; Ackermann-Liebrich, U; Berger, W; Probst-Hensch, NM

2006-01-01

Background Atopy and allergic phenotypes are biologically characterized by an imbalanced T helper cell response skewed towards a type 2 (TH2) immune response associated with elevated serum immunoglobulin E (IgE) levels. Polymorphisms in cytokine genes might modulate regulation of the TH1/TH2 balance. We thus aimed at reproducing our previous findings from a European study population on the association of various cytokine polymorphisms with self-reported hay fever as well as increased total and specific IgE levels in two comparable study populations. Methods Two prospective Caucasian cohorts were used. In the Basel center of the European Community Respiratory Health Survey (ECRHS, n = 418) ten distinct cytokine polymorphisms of putative functional relevance were genotyped. In the Swiss cohort Study on Air Pollution And Lung Disease In Adults (SAPALDIA, n = 6003) two cytokine polymorphisms were genotyped. The associations of these polymorphisms with atopy were estimated by covariance and logistic regression analysis. Results We confirmed IL4, IL10, IL6 and IL18 as candidate genes for atopic health outcomes. In the large, well-characterized SAPALDIA cohort the IL6(-174G>C) and IL18(-137G>C) polymorphisms were associated with circulating total IgE concentrations in subjects with hay fever. The IL18(-137G>C) polymorphism was also associated with the prevalence of hay fever. Conclusion Comprehensive characterization of genetic variation in extended cytokine candidate gene regions is now needed. Large study networks must follow to investigate the association of risk patterns defined by genetic predisposing and environmental risk factors with specific atopic phenotypes. PMID:16759385

Genetic polymorphisms in the IL-18 gene and ulcerative colitis risk: a meta-analysis.

PubMed

Wang, Ying; Tong, Jing; Chang, Bing; Wang, Bai-Fang; Zhang, Dai; Wang, Bing-Yuan

2014-07-01

This meta-analysis was performed to evaluate the relationships between genetic polymorphisms in the IL-18 gene and ulcerative colitis (UC) risk. The PubMed, CISCOM, CINAHL, Web of Science, Google Scholar, EBSCO, Cochrane Library, and CBM databases were searched for relevant articles published before November 1st, 2013 without any language restrictions. Meta-analysis was conducted using the STATA 12.0 software. Crude odds ratios (ORs) with their 95% confidence intervals (95% CI) were calculated. Eight case-control studies with a total of 1000 UC cases and 1392 healthy subjects met the inclusion criteria. Six common polymorphisms in the IL-18 gene were evaluated, including rs1946518 A>C, rs187238 G>C, rs917997 G>A, Codon35, rs1946519 C>A, and rs360718 A>C. The results of our meta-analysis suggest that the IL-18 rs1946518 (allele model: OR=1.22, 95% CI: 1.01-1.48, p=0.039; dominant model: OR=1.44, 95% CI: 1.01-2.06, p=0.045; respectively), rs187238 (allele model: OR=1.38, 95% CI: 1.19-1.61, p<0.001; dominant model: OR=1.50, 95% CI: 1.03-2.19, p=0.034; respectively), and rs360718 (allele model: OR=2.18, 95% CI: 1.22-3.90, p=0.008) polymorphisms might be strongly correlated with an increased risk of UC. A subgroup analysis was conducted to investigate the effect of ethnicity on an individual's risk of UC. Our results revealed positive significant correlations between IL-18 genetic polymorphisms and an increased risk of UC among Asians (allele model: OR=1.36, 95% CI: 1.16-1.60, p<0.001; dominant model: OR=1.50, 95% CI: 1.14-1.98, p=0.004; respectively) and Africans (allele model: OR=1.45, 95% CI: 1.03-2.05, p=0.034), but not among Caucasians (all p>0.05). Our findings provide convincing evidence that IL-18 genetic polymorphisms may contribute to susceptibility to UC, especially the rs1946518, rs187238, and rs360718 polymorphisms among Asians and Africans.

Genome-wide analysis of macrosatellite repeat copy number variation in worldwide populations: evidence for differences and commonalities in size distributions and size restrictions

PubMed Central

2013-01-01

Background Macrosatellite repeats (MSRs), usually spanning hundreds of kilobases of genomic DNA, comprise a significant proportion of the human genome. Because of their highly polymorphic nature, MSRs represent an extreme example of copy number variation, but their structure and function is largely understudied. Here, we describe a detailed study of six autosomal and two X chromosomal MSRs among 270 HapMap individuals from Central Europe, Asia and Africa. Copy number variation, stability and genetic heterogeneity of the autosomal macrosatellite repeats RS447 (chromosome 4p), MSR5p (5p), FLJ40296 (13q), RNU2 (17q) and D4Z4 (4q and 10q) and X chromosomal DXZ4 and CT47 were investigated. Results Repeat array size distribution analysis shows that all of these MSRs are highly polymorphic with the most genetic variation among Africans and the least among Asians. A mitotic mutation rate of 0.4-2.2% was observed, exceeding meiotic mutation rates and possibly explaining the large size variability found for these MSRs. By means of a novel Bayesian approach, statistical support for a distinct multimodal rather than a uniform allele size distribution was detected in seven out of eight MSRs, with evidence for equidistant intervals between the modes. Conclusions The multimodal distributions with evidence for equidistant intervals, in combination with the observation of MSR-specific constraints on minimum array size, suggest that MSRs are limited in their configurations and that deviations thereof may cause disease, as is the case for facioscapulohumeral muscular dystrophy. However, at present we cannot exclude that there are mechanistic constraints for MSRs that are not directly disease-related. This study represents the first comprehensive study of MSRs in different human populations by applying novel statistical methods and identifies commonalities and differences in their organization and function in the human genome. PMID:23496858

Variable association of reactive intermediate genes with systemic lupus erythematosus in populations with different African ancestry.

PubMed

Ramos, Paula S; Oates, James C; Kamen, Diane L; Williams, Adrienne H; Gaffney, Patrick M; Kelly, Jennifer A; Kaufman, Kenneth M; Kimberly, Robert P; Niewold, Timothy B; Jacob, Chaim O; Tsao, Betty P; Alarcón, Graciela S; Brown, Elizabeth E; Edberg, Jeffrey C; Petri, Michelle A; Ramsey-Goldman, Rosalind; Reveille, John D; Vilá, Luis M; James, Judith A; Guthridge, Joel M; Merrill, Joan T; Boackle, Susan A; Freedman, Barry I; Scofield, R Hal; Stevens, Anne M; Vyse, Timothy J; Criswell, Lindsey A; Moser, Kathy L; Alarcón-Riquelme, Marta E; Langefeld, Carl D; Harley, John B; Gilkeson, Gary S

2013-06-01

Little is known about the genetic etiology of systemic lupus erythematosus (SLE) in individuals of African ancestry, despite its higher prevalence and greater disease severity. Overproduction of nitric oxide (NO) and reactive oxygen species are implicated in the pathogenesis and severity of SLE, making NO synthases and other reactive intermediate-related genes biological candidates for disease susceptibility. We analyzed variation in reactive intermediate genes for association with SLE in 2 populations with African ancestry. A total of 244 single-nucleotide polymorphisms (SNP) from 53 regions were analyzed in non-Gullah African Americans (AA; 1432 cases and 1687 controls) and the genetically more homogeneous Gullah of the Sea Islands of South Carolina (133 cases and 112 controls). Single-marker, haplotype, and 2-locus interaction tests were computed for these populations. The glutathione reductase gene GSR (rs2253409; p = 0.0014, OR 1.26, 95% CI 1.09-1.44) was the most significant single SNP association in AA. In the Gullah, the NADH dehydrogenase NDUFS4 (rs381575; p = 0.0065, OR 2.10, 95% CI 1.23-3.59) and NO synthase gene NOS1 (rs561712; p = 0.0072, OR 0.62, 95% CI 0.44-0.88) were most strongly associated with SLE. When both populations were analyzed together, GSR remained the most significant effect (rs2253409; p = 0.00072, OR 1.26, 95% CI 1.10-1.44). Haplotype and 2-locus interaction analyses also uncovered different loci in each population. These results suggest distinct patterns of association with SLE in African-derived populations; specific loci may be more strongly associated within select population groups.

Catechol-O-Methyltransferase Val158Met Polymorphism Associates with Individual Differences in Sleep Physiologic Responses to Chronic Sleep Loss

PubMed Central

Goel, Namni; Banks, Siobhan; Lin, Ling; Mignot, Emmanuel; Dinges, David F.

2011-01-01

Background The COMT Val158Met polymorphism modulates cortical dopaminergic catabolism, and predicts individual differences in prefrontal executive functioning in healthy adults and schizophrenic patients, and associates with EEG differences during sleep loss. We assessed whether the COMT Val158Met polymorphism was a novel marker in healthy adults of differential vulnerability to chronic partial sleep deprivation (PSD), a condition distinct from total sleep loss and one experienced by millions on a daily and persistent basis. Methodology/Principal Findings 20 Met/Met, 64 Val/Met, and 45 Val/Val subjects participated in a protocol of two baseline 10h time in bed (TIB) nights followed by five consecutive 4 h TIB nights. Met/Met subjects showed differentially steeper declines in non-REM EEG slow-wave energy (SWE)—the putative homeostatic marker of sleep drive—during PSD, despite comparable baseline SWE declines. Val/Val subjects showed differentially smaller increases in slow-wave sleep and smaller reductions in stage 2 sleep during PSD, and had more stage 1 sleep across nights and a shorter baseline REM sleep latency. The genotypes, however, did not differ in performance across various executive function and cognitive tasks and showed comparable increases in subjective and physiological sleepiness in response to chronic sleep loss. Met/Met genotypic and Met allelic frequencies were higher in whites than African Americans. Conclusions/Significance The COMT Val158Met polymorphism may be a genetic biomarker for predicting individual differences in sleep physiology—but not in cognitive and executive functioning—resulting from sleep loss in a healthy, racially-diverse adult population of men and women. Beyond healthy sleepers, our results may also provide insight for predicting sleep loss responses in patients with schizophrenia and other psychiatric disorders, since these groups repeatedly experience chronically-curtailed sleep and demonstrate COMT-related treatment responses and risk factors for symptom exacerbation. PMID:22216231

NR3C1 polymorphisms in Brazilians of Caucasian, African, and Asian ancestry: glucocorticoid sensitivity and genotype association.

PubMed

Souza, Manoel Carlos L A; Martins, Clarissa S; Silva-Junior, Ivan M; Chriguer, Rosangela S; Bueno, Ana C; Antonini, Sonir R; Silva, Wilson Araújo; Zago, Marco A; Moreira, Ayrton C; Castro, Margaret de

2014-02-01

The Brazilian population has heterogeneous ethnicity. No previous study evaluated NR3C1 polymorphisms in a Brazilian healthy population. We assessed NR3C1 polymorphisms in Brazilians of Caucasian, African and Asian ancestry (n = 380). In a subgroup (n = 40), we compared the genotypes to glucocorticoid (GC) sensitivity, which was previously evaluated by plasma (PF) and salivary (SF) cortisol after dexamethasone (DEX) suppression tests, GC receptor binding affinity (K d ), and DEX-50% inhibition (IC 50 ) of concanavalin-A-stimulated mononuclear cell proliferation. p.N363S (rs6195), p.ER22/23EK (rs6189-6190), and BclI (rs41423247) allelic discrimination was performed by Real-Time PCR (Polymerase Chain Reaction). Exons 3 to 9 and exon/intron boundaries were amplified by PCR and sequenced. Genotypic frequencies (%) were: rs6195 (n = 380; AA:96.6/AG:3.14/GG:0.26), rs6189-6190 (n = 264; GG:99.6/GA:0.4), rs41423247 (n = 264; CC:57.9/CG:34.1/GG:8.0), rs6188 (n = 155; GG:69.6/GT:25.7/TT:4.7), rs258751 (n = 150; CC:88.0/CT:10.7/TT:1.3), rs6196 (n = 176; TT:77.2/TC:20.4/CC:2.4), rs67300719 (n = 137; CC:99.3/CT:0.7), and rs72542757 (n = 137; CC:99.3/CG:0.7). The rs67300719 and rs72542757 were found only in Asian descendants, in whom p.N363S and p.ER22/23EK were absent. The p.ER22/23EK was observed exclusively in Caucasian descendants. Hardy-Weinberg equilibrium was observed, except in the Asian for rs6188 and rs258751, and in the African for p.N363S. The K d , IC 50 , baseline and after DEX PF or SF did not differ between genotype groups. However, the mean DEX dose that suppressed PF or SF differed among the BclI genotypes (P = 0.03). DEX dose was higher in GG- (0.7 ± 0.2 mg) compared to GC- (0.47 ± 0.2 mg) and CC-carriers (0.47 ± 0.1 mg). The genotypic frequencies of NR3C1 polymorphisms in Brazilians are similar to worldwide populations. Additionally, the BclI polymorphism was associated with altered pituitary-adrenal axis GC sensitivity.

Association Analysis of the Ephrin-B2 Gene in African-Americans with End-Stage Renal Disease

PubMed Central

Hicks, Pamela J.; Staten, Jennifer L.; Palmer, Nicholette D.; Langefeld, Carl D.; Ziegler, Julie T.; Keene, Keith L.; Sale, Michele M.; Bowden, Donald W.; Freedman, Barry I.

2008-01-01

Background Genome scans in African-Americans with end-stage renal disease (ESRD) identified linkage on chromosome 13q33 in the region containing the ephrin-B2 ligand (EFNB2) genes. Interactions between the ephrin-B2 receptor and ephrin-B2 ligand play essential roles in renal angiogenesis, blood vessel maturation, and kidney disease. Methods The EFNB2 gene was evaluated as a positional candidate for non-diabetic and diabetic ESRD susceptibility in 1,071 unrelated African-American subjects; 316 with non-diabetic etiologies of ESRD, 394 with type 2 diabetes-associated ESRD and 361 healthy controls. Single nucleotide polymorphism (SNP) genotyping was performed on the Sequenom Mass Array System. Statistical analyses were computed using Dandelion version 1.26, Snpaddmix version 1.4 and Haploview version 3.32. Results Twenty-eight HapMap tag SNPs were genotyped spanning the 39 kilobases (kb) of the EFNB2 coding region, with average spacing of 1.43 kb. Analysis of 710 ESRD patient samples and 361 controls provided no evidence of single SNP associations in either diabetic or non-diabetic ESRD; although nominal evidence of association with all-cause ESRD was observed with a two SNP (p = 0.022) and three SNP (p = 0.023) haplotype, both containing SNPs rs7490924 and rs2391335 in intron 1. Conclusions Although an attractive positional candidate gene, polymorphisms in the EFNB2 gene do not appear to contribute in a substantial way to non-diabetic, diabetic or all-cause ESRD susceptibility in African-Americans. Additional genes within the chromosome 13q33 linkage interval are likely contributors to African-American non-diabetic ESRD. PMID:18580054

Polymorphic variants of neurotransmitter receptor genes may affect sexual function in aging males: data from the HALS study.

PubMed

Jóźków, Paweł; Słowińska-Lisowska, Małgorzata; Łaczmański, Łukasz; Mędraś, Marek

2013-01-01

Human behavior is influenced by a number of brain neurotransmitters. Central dopamine, serotonin and melanocortin systems have special importance for male sexual function. We searched for associations between male aging symptoms and polymorphic sites of serotonin (5-HTR1B), melanocortin (MC4R) and dopamine (DRD2, DRD4) receptors. In a population-based sample, genotyping of 5-HTR1B (polymorphism: G861C), MC4R (polymorphisms: C-2745T, Val103Ile), DRD2 (polymorphism: C313T) and DRD4 (polymorphism: 48-bp VNTR) was performed in 387 healthy men. The Aging Males' Symptoms (AMS) scale was used to evaluate specific ailments of aging men. We analyzed answers to questions from the AMS scale. Five points of the questionnaire addressed sexual symptoms of the aging male: feeling of passing one's peak, decrease in beard growth, decrease in ability/frequency to perform sexually, decrease in the number of morning erections, and decrease in sexual desire/libido (lacking pleasure in sex, lacking desire for sexual intercourse). Relations between reported symptoms and variants of the polymorphic sites of the studied genes were assessed. After adjusting for confounding factors (education, arterial hypertension, physical activity, weight, waist circumference) an association between the sexual dimension of AMS and genetic variants of 5-HTR1B G861C (p = 0.04) was observed. Variability of neurotransmitter receptor genes may be associated with sexual symptoms of aging in men. Copyright © 2013 S. Karger AG, Basel.

Androgen Receptor Gene Polymorphisms and Alterations in Prostate Cancer: Of Humanized Mice and Men

PubMed Central

Robins, Diane M.

2011-01-01

Germline polymorphisms and somatic mutations of the androgen receptor (AR) have been intensely investigated in prostate cancer but even with genomic approaches their impact remains controversial. To assess the functional significance of AR genetic variation, we converted the mouse gene to the human sequence by germline recombination and engineered alleles to query the role of a polymorphic glutamine (Q) tract implicated in cancer risk. In a prostate cancer model, AR Q tract length influences progression and castration response. Mutation profiling in mice provides direct evidence that somatic AR variants are selected by therapy, a finding validated in human metastases from distinct treatment groups. Mutant ARs exploit multiple mechanisms to resist hormone ablation, including alterations in ligand specificity, target gene selectivity, chaperone interaction and nuclear localization. Regardless of their frequency, these variants permute normal function to reveal novel means to target wild type AR and its key interacting partners. PMID:21689727

X-ray crystallography, an essential tool for the determination of thermodynamic relationships between crystalline polymorphs.

PubMed

Céolin, R; Rietveld, I-B

2016-01-01

After a short review of the controversies surrounding the discovery of crystalline polymorphism in relation to our present day understanding, the methods of how to solve the stability hierarchy of different polymorphs will be briefly discussed. They involve either theoretical calculations, or, more commonly, experimental methods based on classical thermodynamics. The experimental approach is mainly carried out using heat-exchange data associated to the transition of one form into another. It will be demonstrated that work-related data associated to the phase transition should be taken into account and the role of X-ray crystallography therein will be discussed. X-ray crystallography has become increasingly precise and can nowadays provide specific volumes and their differences as a function of temperature, and also as a function of pressure, humidity, and time. Copyright © 2015 Académie Nationale de Pharmacie. Published by Elsevier Masson SAS. All rights reserved.

Associations between HDL-cholesterol and polymorphisms in hepatic lipase and lipoprotein lipase genes are modified by dietary fat intake in African American and White Adults 123

PubMed Central

Nettleton, Jennifer A.; Steffen, Lyn M.; Ballantyne, Christie M.; Boerwinkle, Eric; Folsom, Aaron R.

2008-01-01

Polymorphisms in genes involved in HDL-cholesterol (HDL-C) metabolism influence plasma HDL-C concentrations. We examined whether dietary fat intake modified relations between HDL-C and polymorphisms in hepatic lipase (LIPC-514C→T), cholesteryl ester transfer protein (CETP TaqIB), and lipoprotein lipase (LPL S447X) genes. Diet (food frequency questionnaire), plasma lipids, and LIPC, CETP, and LPL genotypes were assessed in ~12,000 White and African American adults. In both races and all genotypes studied, minor allele homozygotes had highest HDL-C concentrations compared to the other genotypes (P <0.001). However, main effects were modified by usual dietary fat intake. In African Americans— women somewhat more strongly than men— LIPC TT homozygotes with fat intake ≥33.2% of energy had ~3-4 mg/dL higher HDL-C concentrations than CC and CT genotypes. In contrast, when fat intake was <33.2% of energy, TT homozygotes had HDL-C concentrations ~3.5 mg/dL greater than those with the CC genotype but not different from those with the CT genotype (Pinteraction =0.013). In Whites, LPL GG homozygotes had greatest HDL-C at lower total, saturated, and monounsaturated fat intakes but lowest HDL-C at higher intakes of these fats (Pinteraction ≤0.002). Dietary fat did not modify associations between CETP and HDL-C. In conclusion, these data show that plasma HDL-C differs according to LIPC, LPL, and CETP genotypes. In the case of LIPC and LPL, data suggest dietary fat modifies these relations. PMID:17157861

Candidate genes have sex-specific effects on timing of spring migration and moult speed in a long-distance migratory bird.

PubMed

Bazzi, Gaia; Podofillini, Stefano; Gatti, Emanuele; Gianfranceschi, Luca; Cecere, Jacopo G; Spina, Fernando; Saino, Nicola; Rubolini, Diego

2017-10-01

The timing of major life-history events, such as migration and moult, is set by endogenous circadian and circannual clocks, that have been well characterized at the molecular level. Conversely, the genetic sources of variation in phenology and in other behavioral traits have been sparsely addressed. It has been proposed that inter-individual variability in the timing of seasonal events may arise from allelic polymorphism at phenological candidate genes involved in the signaling cascade of the endogenous clocks. In this study of a long-distance migratory passerine bird, the willow warbler Phylloscopus trochilus , we investigated whether allelic variation at 5 polymorphic loci of 4 candidate genes ( Adcyap1 , Clock , Creb1 , and Npas2 ), predicted 2 major components of the annual schedule, namely timing of spring migration across the central Mediterranean sea and moult speed, the latter gauged from ptilochronological analyses of tail feathers moulted in the African winter quarters. We identified a novel Clock gene locus ( Clock region 3) showing polyQ polymorphism, which was however not significantly associated with any phenotypic trait. Npas2 allele size predicted male (but not female) spring migration date, with males bearing longer alleles migrating significantly earlier than those bearing shorter alleles. Creb1 allele size significantly predicted male (but not female) moult speed, longer alleles being associated with faster moult. All other genotype-phenotype associations were statistically non-significant. These findings provide new evidence for a role of candidate genes in modulating the phenology of different circannual activities in long-distance migratory birds, and for the occurrence of sex-specific candidate gene effects.

β2-Adrenergic receptor promoter haplotype influences the severity of acute viral respiratory tract infection during infancy: a prospective cohort study.

PubMed

Wu, Pingsheng; Larkin, Emma K; Reiss, Sara S; Carroll, Kecia N; Summar, Marshall L; Minton, Patricia A; Woodward, Kimberly B; Liu, Zhouwen; Islam, Jessica Y; Hartert, Tina V; Moore, Paul E

2015-09-14

Despite the significant interest in β2-Adrenergic receptor (ADRB2) polymorphisms related to asthma, whether ADRB2 genetic variants are similarly associated with acute respiratory tract infections have not been studied. We hypothesized that genetic variants in ADRB2 associated with a response to asthma therapy during an asthma exacerbation were also associated with severity of acute respiratory tract infections. To test this hypothesis, we genotyped 5 common polymorphisms in the promoter region and coding block of the ADRB2 gene (loci -2387, -2274, -1343, +46, and +79) from 374 Caucasian and African American term infants who were enrolled at the time of acute respiratory illness over four respiratory viral seasons. Severity of respiratory tract infections was measured using a bronchiolitis severity score (BSS; range = 0-12, clinically significant difference = 0.5) with a higher score indicating more severe disease. We assigned the promoter, coding and combined promoter and coding haplotypes to the unphased genotype data. The associations between each of these five single-nucleotide polymorphisms (SNPs) as well as the haplotypes and infant BSS were analyzed using nonparametric univariate analysis and multivariable proportional odds model separately in Caucasians and African Americans. There was no significant association between infant BSS and each of the SNPs in both Caucasians and African Americans. However, promoter haplotype CCA was associated with a decreased BSS in African Americans in a dose dependent manner. The median (interquartile range) BSS of infants with no copies of the CCA haplotype, one copy, and two copies of the CCA haplotype were 5.5 (2.0, 8.0), 4.0 (1.0, 7.5), and 3.0 (1.0, 4.0), respectively. This dose dependent relationship persisted after adjusting for infant age, gender, daycare exposure, secondhand smoke exposure, prior history of breastfeeding, siblings at home, and enrollment season (adjusted odds ratio: 0.59, 95% confidence interval: 0.36, 0.98). There was no similar protective relationship of haplotype CCA on severity of respiratory tract infections identified in Caucasians. ADRB2 genotype may be predictive of severity of acute respiratory tract infections in African Americans, and potentially identify a subset of infants who may respond to beta-agonist therapy.

Association of polymorphisms in genes of factors involved in regulation of splicing of cystic fibrosis transmembrane conductance regulator mRNA with acute respiratory distress syndrome in children with pneumonia.

PubMed

Perez-Marques, Francesca; Simpson, Pippa; Yan, Ke; Quasney, Michael W; Halligan, Nadine; Merchant, Daniel; Dahmer, Mary K

2016-09-05

Previous work has demonstrated a strong association between lung injury in African American children with pneumonia and a polymorphic (TG)mTn region in cystic fibrosis transmembrane conductance (CFTR) involved in the generation of a nonfunctional CFTR protein lacking exon 9. A number of splicing factors that regulate the inclusion/exclusion of exon 9 have been identified. The objective of this study was to determine whether genetic variants in these splicing factors were associated with acute respiratory distress syndrome (ARDS) in children with pneumonia. This is a prospective cohort genetic association study of lung injury in African American and non-Hispanic Caucasian children with community-acquired pneumonia evaluated in the emergency department or admitted to the hospital. Linkage-disequilibrium-tag single nucleotide polymorphisms (LD-tag SNPs) in genes of the following splicing factors (followed by gene name) involved in exon 9 skipping PTB1 (PTBP1), SRp40 (SFRS1), SR2/ASF (SFRS5), TDP-43 (TARDBP), TIA-1 (TIA1), and U2AF(65) (U2AF2) were genotyped. SNPs in the gene of the splicing factor CELF2 (CELF2) were selected by conservation score. Multivariable analysis was used to examine association between genotypes and ARDS. The African American cohort (n = 474) had 29 children with ARDS and the non-Hispanic Caucasian cohort (n = 304) had 32 children with ARDS. In the African American group multivariable analysis indicated that three variants in CELF2, rs7068124 (p = 0.004), rs3814634 (p = 0.032) and rs10905928 (p = 0.044), and two in TIA1, rs2592178 (p = 0.005) and rs13402990 (p = 0.018) were independently associated with ARDS. In the non-Hispanic Caucasian group, a single variant in CELF2, rs2277212 (p = 0.014), was associated with increased risk of developing ARDS. The data indicate that SNPs in CELF2 may be associated with the risk of developing ARDS in both African American and non-Hispanic Caucasian children with pneumonia and suggest that the potential role of the splicing factor CELF2 in ARDS should be explored further.

Worldwide patterns of ancestry, divergence, and admixture in domesticated cattle

USDA-ARS?s Scientific Manuscript database

The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 anima...

Neuroantibodies (NAB) in African-American Children: Associations with Gender, Glutathione-S-Transferase (GST)Pi Polymorphisms (SNP) and Heavy Metals

EPA Science Inventory

CONTACT (NAME ONLY): Hassan El-Fawal Abstract Details PRESENTATION TYPE: Platform or Poster CURRENT CATEGORY: Neurodegenerative Disease | Biomarkers | Neurotoxicity, Metals KEYWORDS: Autoantibodies, Glutathione-S-Transferase, DATE/TIME LAST MODIFIED: DATE/TIME SUBMITTED: Abs...

Genetic and epigenetic variation in the lineage specification of regulatory T cells

PubMed Central

Arvey, Aaron; van der Veeken, Joris; Plitas, George; Rich, Stephen S; Concannon, Patrick; Rudensky, Alexander Y

2015-01-01

Regulatory T (Treg) cells, which suppress autoimmunity and other inflammatory states, are characterized by a distinct set of genetic elements controlling their gene expression. However, the extent of genetic and associated epigenetic variation in the Treg cell lineage and its possible relation to disease states in humans remain unknown. We explored evolutionary conservation of regulatory elements and natural human inter-individual epigenetic variation in Treg cells to identify the core transcriptional control program of lineage specification. Analysis of single nucleotide polymorphisms in core lineage-specific enhancers revealed disease associations, which were further corroborated by high-resolution genotyping to fine map causal polymorphisms in lineage-specific enhancers. Our findings suggest that a small set of regulatory elements specify the Treg lineage and that genetic variation in Treg cell-specific enhancers may alter Treg cell function contributing to polygenic disease. DOI: http://dx.doi.org/10.7554/eLife.07571.001 PMID:26510014

Multi-Ancestral Analysis of Inflammation-Related Genetic Variants and C-Reactive Protein in the Population Architecture using Genomics and Epidemiology (PAGE) Study

PubMed Central

Kocarnik, Jonathan M.; Pendergrass, Sarah A.; Carty, Cara L.; Pankow, James S.; Schumacher, Fredrick R.; Cheng, Iona; Durda, Peter; Ambite, JoséLuis; Deelman, Ewa; Cook, Nancy R.; Liu, Simin; Wactawski-Wende, Jean; Hutter, Carolyn; Brown-Gentry, Kristin; Wilson, Sarah; Best, Lyle G.; Pankratz, Nathan; Hong, Ching-Ping; Cole, Shelley A.; Voruganti, V. Saroja; Bůžková, Petra; Jorgensen, Neal W.; Jenny, Nancy S.; Wilkens, Lynne R.; Haiman, Christopher A.; Kolonel, Laurence N.; LaCroix, Andrea; North, Kari; Jackson, Rebecca; Le Marchand, Loic; Hindorff, Lucia A.; Crawford, Dana C.; Gross, Myron; Peters, Ulrike

2014-01-01

Background C-reactive protein (CRP) is a biomarker of inflammation. Genome-wide association studies (GWAS) have identified single nucleotide polymorphisms (SNPs) associated with CRP concentrations and inflammation-related traits such as cardiovascular disease, type 2 diabetes, and obesity. We aimed to replicate previous CRP-SNP associations, assess whether these associations generalize to additional race/ethnicity groups, and evaluate inflammation-related SNPs for a potentially pleiotropic association with CRP. Methods and Results We selected and analyzed 16 CRP-associated and 250 inflammation-related GWAS SNPs among 40,473 African American, American Indian, Asian/Pacific Islander, European American, and Hispanic participants from 7 studies collaborating in the Population Architecture using Genomics and Epidemiology (PAGE) study. Fixed-effect meta-analyses combined study-specific race/ethnicity-stratified linear regression estimates to evaluate the association between each SNP and high-sensitivity CRP. Overall, 18 SNPs in 8 loci were significantly associated with CRP (Bonferroni-corrected p<3.1×10−3 for replication, p<2.0×10−4 for pleiotropy): Seven of these were specific to European Americans, while 9 additionally generalized to African Americans (1), Hispanics (5), or both (3); 1 SNP was seen only in African Americans and Hispanics. Two SNPs in the CELSR2/PSRC1/SORT1 locus showed a potentially novel association with CRP: rs599839 (p=2.0×10−6) and rs646776 (p=3.1×10−5). Conclusions We replicated 16 SNP-CRP associations, 10 of which generalized to African Americans and/or Hispanics. We also identified potentially novel pleiotropic associations with CRP for two SNPs previously associated with coronary artery disease and LDL cholesterol. These findings demonstrate the benefit of evaluating genotype-phenotype associations in multiple race/ethnicity groups, and of looking for pleiotropic relationships among SNPs previously associated with related phenotypes. PMID:24622110

Multiancestral analysis of inflammation-related genetic variants and C-reactive protein in the population architecture using genomics and epidemiology study.

PubMed

Kocarnik, Jonathan M; Pendergrass, Sarah A; Carty, Cara L; Pankow, James S; Schumacher, Fredrick R; Cheng, Iona; Durda, Peter; Ambite, José Luis; Deelman, Ewa; Cook, Nancy R; Liu, Simin; Wactawski-Wende, Jean; Hutter, Carolyn; Brown-Gentry, Kristin; Wilson, Sarah; Best, Lyle G; Pankratz, Nathan; Hong, Ching-Ping; Cole, Shelley A; Voruganti, V Saroja; Bůžkova, Petra; Jorgensen, Neal W; Jenny, Nancy S; Wilkens, Lynne R; Haiman, Christopher A; Kolonel, Laurence N; Lacroix, Andrea; North, Kari; Jackson, Rebecca; Le Marchand, Loic; Hindorff, Lucia A; Crawford, Dana C; Gross, Myron; Peters, Ulrike

2014-04-01

C-reactive protein (CRP) is a biomarker of inflammation. Genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) associated with CRP concentrations and inflammation-related traits such as cardiovascular disease, type 2 diabetes mellitus, and obesity. We aimed to replicate previous CRP-SNP associations, assess whether these associations generalize to additional race/ethnicity groups, and evaluate inflammation-related SNPs for a potentially pleiotropic association with CRP. We selected and analyzed 16 CRP-associated and 250 inflammation-related GWAS SNPs among 40 473 African American, American Indian, Asian/Pacific Islander, European American, and Hispanic participants from 7 studies collaborating in the Population Architecture using Genomics and Epidemiology (PAGE) study. Fixed-effect meta-analyses combined study-specific race/ethnicity-stratified linear regression estimates to evaluate the association between each SNP and high-sensitivity CRP. Overall, 18 SNPs in 8 loci were significantly associated with CRP (Bonferroni-corrected P<3.1×10(-3) for replication, P<2.0×10(-4) for pleiotropy): Seven of these were specific to European Americans, while 9 additionally generalized to African Americans (1), Hispanics (5), or both (3); 1 SNP was seen only in African Americans and Hispanics. Two SNPs in the CELSR2/PSRC1/SORT1 locus showed a potentially novel association with CRP: rs599839 (P=2.0×10(-6)) and rs646776 (P=3.1×10(-5)). We replicated 16 SNP-CRP associations, 10 of which generalized to African Americans and/or Hispanics. We also identified potentially novel pleiotropic associations with CRP for two SNPs previously associated with coronary artery disease and/or low-density lipoprotein-cholesterol. These findings demonstrate the benefit of evaluating genotype-phenotype associations in multiple race/ethnicity groups and looking for pleiotropic relationships among SNPs previously associated with related phenotypes.

Sex, Drugs, and Rock ‘N’ Roll: Hypothesizing Common Mesolimbic Activation as a Function of Reward Gene Polymorphisms

PubMed Central

Blum, Kenneth; Werner, Tonia; Carnes, Stefanie; Carnes, Patrick; Bowirrat, Abdalla; Giordano, John; Marlene-Oscar-Berman; Gold, Mark

2014-01-01

The nucleus accumbens, a site within the ventral striatum, plays a prominent role in mediating the reinforcing effects of drugs of abuse, food, sex, and other addictions. Indeed, it is generally believed that this structure mandates motivated behaviors such as eating, drinking, and sexual activity, which are elicited by natural rewards and other strong incentive stimuli. This article focuses on sex addiction, but we hypothesize that there is a common underlying mechanism of action for the powerful effects that all addictions have on human motivation. That is, biological drives may have common molecular genetic antecedents, which if impaired, lead to aberrant behaviors. Based on abundant scientific support, we further hypothesize that dopaminergic genes, and possibly other candidate neurotransmitter-related gene polymorphisms, affect both hedonic and anhedonic behavioral outcomes. Genotyping studies already have linked gene polymorphic associations with alcohol and drug addictions and obesity, and we anticipate that future genotyping studies of sex addicts will provide evidence for polymorphic associations with specific clustering of sexual typologies based on clinical instrument assessments. We recommend that scientists and clinicians embark on research coupling the use of neuroimaging tools with dopaminergic agonistic agents to target specific gene polymorphisms systematically for normalizing hyper- or hypo-sexual behaviors. PMID:22641964

The haptoglobin promoter polymorphism rs5471 is the most definitive genetic determinant of serum haptoglobin level in a Ghanaian population.

PubMed

Soejima, Mikiko; Teye, Kwesi; Koda, Yoshiro

2018-08-01

The serum haptoglobin (HP) level varies in various clinical conditions and among individuals. Recently, the common HP alleles, rs5472, and rs2000999 have been reported to associate with serum HP level, but no studies have been done on Africans. Here, we explored the relationship of not only these polymorphisms but also rs5470 and rs5471 to the serum HP level in 121 Ghanaians. Genotyping of rs2000999 was performed by PCR using hydrolysis probes, while the other polymorphisms have been already genotyped. Serum HP level was measured by a sandwich ELISA. We observed a significant association between rs5471 and the serum HP level (p = 0.026). It was also observed within the subgroups of HP 2 /HP 2 and HP 2 /HP 1 . In addition, we detected a trend toward lower HP levels for individuals with the A allele of rs2000999 than those without A, but it was not statistically significant (p = 0.156). However, we did not observe the clear associations between other polymorphisms and serum HP level that were observed for Europeans and Asians because of the small sample size and the complexity of SNPs affecting the HP level. We suggest that rs5471 is a strong genetic determinant of HP levels in Ghanaians, and this seems to be characteristic of Africans. Further investigation using large scale samples will help in understanding the genetic background of individual variability of the serum HP level. Copyright © 2018 Elsevier B.V. All rights reserved.

Range and Frequency of Africanized Honey Bees in California (USA)

PubMed Central

Kono, Yoshiaki; Kohn, Joshua R.

2015-01-01

Africanized honey bees entered California in 1994 but few accounts of their northward expansion or their frequency relative to European honey bees have been published. We used mitochondrial markers and morphometric analyses to determine the prevalence of Africanized honeybees in San Diego County and their current northward progress in California west of the Sierra Nevada crest. The northernmost African mitotypes detected were approximately 40 km south of Sacramento in California’s central valley. In San Diego County, 65% of foraging honey bee workers carry African mitochondria and the estimated percentage of Africanized workers using morphological measurements is similar (61%). There was no correlation between mitotype and morphology in San Diego County suggesting Africanized bees result from bidirectional hybridization. Seventy percent of feral hives, but only 13% of managed hives, sampled in San Diego County carried the African mitotype indicating that a large fraction of foraging workers in both urban and rural San Diego County are feral. We also found a single nucleotide polymorphism at the DNA barcode locus COI that distinguishes European and African mitotypes. The utility of this marker was confirmed using 401 georeferenced honey bee sequences from the worldwide Barcode of Life Database. Future censuses can determine whether the current range of the Africanized form is stable, patterns of introgression at nuclear loci, and the environmental factors that may limit the northern range of the Africanized honey bee. PMID:26361047

Lessons from the canine Oxtr gene: populations, variants and functional aspects.

PubMed

Bence, M; Marx, P; Szantai, E; Kubinyi, E; Ronai, Z; Banlaki, Z

2017-04-01

Oxytocin receptor (OXTR) acts as a key behavioral modulator of the central nervous system, affecting social behavior, stress, affiliation and cognitive functions. Variants of the Oxtr gene are known to influence behavior both in animals and humans; however, canine Oxtr polymorphisms are less characterized in terms of possible relevance to function, selection criteria in breeding and domestication. In this report, we provide a detailed characterization of common variants of the canine Oxtr gene. In particular (1) novel polymorphisms were identified by direct sequencing of wolf and dog samples, (2) allelic distributions and pairwise linkage disequilibrium patterns of several canine populations were compared, (3) neighbor joining (NJ) tree based on common single nucleotide polymorphisms (SNPs) was constructed, (4) mRNA expression features were assessed, (5) a novel splice variant was detected and (6) in vitro functional assays were performed. Results indicate marked differences regarding Oxtr variations between purebred dogs of different breeds, free-ranging dog populations, wolf subspecies and golden jackals. This, together with existence of explicitly dog-specific alleles and data obtained from the NJ tree implies that Oxtr could indeed have been a target gene during domestication and selection for human preferred aspects of temperament and social behavior. This assumption is further supported by the present observations on gene expression patterns within the brain and luciferase reporter experiments, providing a molecular level link between certain canine Oxtr polymorphisms and differences in nervous system function and behavior. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Population-based analysis of the frequency of HFE gene polymorphisms: Correlation with the susceptibility to develop hereditary hemochromatosis.

PubMed

Katsarou, Martha-Spyridoula; Latsi, Rosana; Papasavva, Maria; Demertzis, Nikolaos; Kalogridis, Thodoris; Tsatsakis, Aristides M; Spandidos, Demetrios A; Drakoulis, Nikolaos

2016-07-01

Hereditary hemochromatosis (HH) is an autosomal recessive genetic disease, characterized by increased dietary iron absorption. Due to the absence of an effective excretory mechanism, the excess iron in the body may accumulate resulting in toxic effects. The HFE gene also affects the activity of hepcidin, a hormone which acts as a negative regulator of iron metabolism. In this study, we performed a population-based analysis of the distribution of three hemochromatosis-related polymorphisms in the HFE gene (rs1800562, rs1799945 and rs1800730). DNA from 1,446 non‑related individuals of Greek ethnicity was collected and analyzed, either from whole blood or buccal swabs. The frequency distribution of these HFE gene polymorphisms was then determined. The results revealed that in our Greek population cohort (gr) the frequencies of each polymorphism were as follows: rs1800562: GG (wild‑type)=97.0%, GA=1.5%, AA=1.5%; rs1799945: CC (wild‑type)=74.4%, CG=23.4%, GG=2.2%; rs1800730: AA (wild‑type)=98.1%, AT=1.5% and TT=0.4%. No association between the HFE polymorphisms rs1800562, rs1799945 and rs1800730 and gender could be established. As regards the rs1800562 polymorphism, the A allele (mutant) was ~1.8‑fold more frequent in the European population (eur) than in the Greek population [(gr)=2,3%<(eur)=4%]. As for the rs1799945 polymorphism, the G allele (mutant) was 1.2‑fold more frequent in the European population than in the Greek population [(gr)=13,9%<(eur)=17%]. As regards the rs1800730 polymorphism, the T allele (mutant) was ~1.7‑fold more frequent in the European population than in the Greek population [(gr)=1.2%<(eur)=2%]. However, these pathogenic mutations were found more frequently in the Greek population compared to the global population (gl) [rs1800562: (gl)=1%<(gr)=2,3%; rs1799945: (gl)=7%<(gr)=13,9%; rs1800730: (gl)=<1%<(gr)=1.2%]. This suggests that the Greek population may differ genetically from the northern European population, due to influences from neighboring Asian and African populations. These findings also suggest that there is no gender-associated inheritance of these polymorphisms, and gender-specific symptoms appear as a result of independent biological processes. Thus, the early detection of the tendency towards iron accumulation may be achieved by the genotypic analysis of the polymorphisms that may contribute to the development of the hemochromatosis.

In vitro susceptibility to quinine and microsatellite variations of the Plasmodium falciparum Na+/H+ exchanger (Pfnhe-1) gene: the absence of association in clinical isolates from the Republic of Congo

PubMed Central

2011-01-01

Background Quinine is still recommended as an effective therapy for severe cases of Plasmodium falciparum malaria, but the parasite has developed resistance to the drug in some cases. Investigations into the genetic basis for quinine resistance (QNR) suggest that QNR is complex and involves several genes, with either an additive or a pairwise effect. The results obtained when assessing one of these genes, the plasmodial Na+/H+ exchanger, Pfnhe-1, were found to depend upon the geographic origin of the parasite strain. Most of the associations identified have been made in Asian strains; in contrast, in African strains, the influence of Pfnhe on QNR is not apparent. However, a recent study carried out in Kenya did show a significant association between a Pfnhe polymorphism and QNR. As genetic differences may exist across the African continent, more field data are needed to determine if this association exists in other African regions. In the present study, association between Pfnhe and QNR is investigated in a series of isolates from central Africa. Methods The sequence analysis of the polymorphisms at the Pfnhe-1 ms4760 microsatellite and the evaluation of in vitro quinine susceptibility (by isotopic assay) were conducted in 74 P. falciparum isolates from the Republic of Congo. Results Polymorphisms in the number of DNNND or NHNDNHNNDDD repeats in the Pfnhe-1 ms4760 microsatellite were not associated with quinine susceptibility. Conclusions The polymorphism in the microsatellite ms4760 in Pfnhe-1 that cannot be used to monitor quinine response in the regions of the Republic of Congo, where the isolates came from. This finding suggests that there exists a genetic background associated with geographic area for the association that will prevent the use of Pfnhe as a molecular marker for QNR. The contribution of Pfnhe to the in vitro response to quinine remains to be assessed in other regions, including in countries with different levels of drug pressure. PMID:21314947

Y-chromosome lineages in Cabo Verde Islands witness the diverse geographic origin of its first male settlers.

PubMed

Gonçalves, Rita; Rosa, Alexandra; Freitas, Ana; Fernandes, Ana; Kivisild, Toomas; Villems, Richard; Brehm, António

2003-11-01

The Y-chromosome haplogroup composition of the population of the Cabo Verde Archipelago was profiled by using 32 single-nucleotide polymorphism markers and compared with potential source populations from Iberia, west Africa, and the Middle East. According to the traditional view, the major proportion of the founding population of Cabo Verde was of west African ancestry with the addition of a minor fraction of male colonizers from Europe. Unexpectedly, more than half of the paternal lineages (53.5%) of Cabo Verdeans clustered in haplogroups I, J, K, and R1, which are characteristic of populations of Europe and the Middle East, while being absent in the probable west African source population of Guiné-Bissau. Moreover, a high frequency of J* lineages in Cabo Verdeans relates them more closely to populations of the Middle East and probably provides the first genetic evidence of the legacy of the Jews. In addition, the considerable proportion (20.5%) of E3b(xM81) lineages indicates a possible gene flow from the Middle East or northeast Africa, which, at least partly, could be ascribed to the Sephardic Jews. In contrast to the predominance of west African mitochondrial DNA haplotypes in their maternal gene pool, the major west African Y-chromosome lineage E3a was observed only at a frequency of 15.9%. Overall, these results indicate that gene flow from multiple sources and various sex-specific patterns have been important in the formation of the genomic diversity in the Cabo Verde islands.

Vitamin D receptor genetic polymorphisms and tuberculosis: updated systematic review and meta-analysis.

PubMed

Gao, L; Tao, Y; Zhang, L; Jin, Q

2010-01-01

Host genetic susceptibility has been suggested as one of the most important explanations for inter-individual differences in tuberculosis (TB) risk. The vitamin D receptor (VDR) gene has been studied as a candidate locus due to genetic polymorphisms that affects the activity of the receptor and subsequent downstream vitamin D-mediated effects. We reviewed published studies on VDR polymorphisms and TB susceptibility up to 15 April 2009 and quantitatively summarised associations of the most widely studied polymorphisms (FokI, TaqI, ApaI and BsmI) using meta-analysis. A total of 23 eligible studies were included in this review. Heterogeneous results were observed, which may be partly explained by the differences between populations. Among Asians, the FokI ff genotype showed a pronounced positive association (OR 2.0, 95%CI 1.3-3.2), a significant inverse association was observed for the BsmI bb genotype (OR 0.5, 95%CI 0.4-0.8), and marginal significant associations were found for TaqI and ApaI polymorphisms. However, none of the polymorphisms was significantly related to TB among Africans or South Americans. The association of VDR polymorphisms with risk of TB observed in our analyses supports the hypothesis that vitamin D deficiency might play a role as risk factor during the development of TB.

Allelic inhibition of displacement activity: a simplified one tube allele-specific PCR for evaluation of ITPA polymorphisms.

PubMed

Galmozzi, E; Facchetti, F; Degasperi, E; Aghemo, A; Lampertico, P

2013-02-01

Recently, genome-wide association studies (GWAS) in patients with chronic hepatitis C virus (HCV) infection have identified two functional single nucleotide polymorphisms (SNPs) in the inosine triphosphatase (ITPA) gene, that are associated strongly and independently with hemolytic anemia in patients exposed to pegylated-interferon (Peg-IFN) plus ribavirin (RBV) combined therapy. Here has been developed a simplified allele discrimination polymerase chain reaction (PCR) assay named allelic inhibition of displacement activity (AIDA) for evaluation of ITPA polymorphisms. AIDA system relies on three unlabeled primers only, two outer common primers and one inner primer with allele-specific 3' terminus mismatch. DNA samples from 192 patients with chronic HCV infection were used to validate the AIDA system and results were compared with the gold standard TaqMan(®) SNP genotyping assay. Concordant data were obtained for all samples, granting for high specificity of the method. In conclusion, AIDA is a practical one-tube method to reproducibly and to assess accurately rs7270101 and rs1127354 ITPA SNPs. Copyright © 2012 Elsevier B.V. All rights reserved.

Functional characterization of polymorphisms in DNA repair genes using cytogenetic challenge assays.

PubMed

Au, William W; Salama, Salama A; Sierra-Torres, Carlos H

2003-11-01

A major barrier to understanding the role of polymorphic DNA repair genes for environmental cancer is that the functions of variant genotypes are largely unknown. Using our cytogenetic challenge assays, we conducted an investigation to address the deficiency. Using X-rays or ultraviolet (UV) light, we irradiated blood lymphocytes from 80 nonsmoking donors to challenge the cells to repair the induced DNA damage, and we analyzed expression of chromosome aberrations (CA) specific to the inducing agents. We have genotyped polymorphic DNA repair genes preferentially involved with base excision repair (BER) and nucleotide excision repair (NER) activities (XRCC1, XRCC3, APE1, XPD) corresponding to the repair of X-ray- and UV light-induced DNA damage, respectively. We expected that defects in specific DNA repair pathways due to polymorphisms would cause corresponding increases of specific CA. From our data, XRCC1 399Gln and XRCC3 241Met were associated with significant increases in chromosome deletions compared with the corresponding homozygous wild types (18.27 1.1 vs 14.79 1.2 and 18.22 0.99 vs 14.20 1.39, respectively); XPD 312Asn and XPD 751Gln were associated with significant increases in chromatid breaks compared with wild types (16.09 1.36 vs 11.41 0.98 and 16.87 1.27 vs 10.54 0.87, respectively), p < 0.05. The data indicate that XRCC1 399Gln and XRCC3 241Met are significantly defective in BER, and the XPD 312Asn and XPD 751Gln are significantly defective in NER. In addition, the variant genotypes interact significantly, with limited overlap of the two different repair pathways.

Effect of ethanol on crystallization of the polymorphs of L-histidine

NASA Astrophysics Data System (ADS)

Wantha, Lek; Punmalee, Neeranuch; Sawaddiphol, Vanida; Flood, Adrian E.

2018-05-01

It is known that the antisolvents used for crystallization can affect the crystallization outcome and may promote the crystallization of a specific polymorph. In this study L-histidine (L-his) is used as a model substance, and ethanol was selected to be an antisolvent. The formation of the polymorphs of L-his in antisolvent crystallization as a function of supersaturation, ethanol volume fraction, and temperature was studied. The induction time for the antisolvent crystallization was also measured. The results showed that the induction time decreases with higher supersaturation and ethanol volume fraction, indicating that the nucleation rate of L-his from antisolvent crystallization (where water was used as the solvent and ethanol as the antisolvent) increases with higher supersaturation, as expected, and ethanol fraction. At all temperatures studied, the pure metastable polymorph B of L-his was obtained initially at higher ethanol volume fraction and supersaturation, while a mixture of the polymorphs A and B was obtained at lower ethanol volume fraction and supersaturation.

Genetic polymorphism and prostate cancer aggressiveness: a case-only study of 1,536 GWAS and candidate SNPs in African-Americans and European-Americans.

PubMed

Bensen, Jeannette T; Xu, Zongli; Smith, Gary J; Mohler, James L; Fontham, Elizabeth T H; Taylor, Jack A

2013-01-01

Genome-wide association studies have established a number of replicated single nucleotide polymorphisms (SNPs) for susceptibility to prostate cancer (CaP), but it is unclear whether these susceptibility SNPs are also associated with disease aggressiveness. This study evaluates whether such replication SNPs or other candidate SNPs are associated with CaP aggressiveness in African-American (AA) and European-American (EA) men. A 1,536 SNP panel which included 34 genome-wide association study (GWAS) replication SNPs, 38 flanking SNPs, a set of ancestry informative markers, and SNPs in candidate genes and other areas was genotyped in 1,060 AA and 1,087 EA men with incident CaP from the North Carolina-Louisiana Prostate Cancer Project (PCaP). Tests for association were conducted using ordinal logistic regression with a log-additive genotype model and a 3-category CaP aggressiveness variable. Four GWAS replication SNPs (rs2660753, rs13254738, rs10090154, rs2735839) and seven flanking SNPs were associated with CaP aggressiveness (P < 0.05) in three genomic regions: One at 3p12 (EA), seven at 8q24 (5 AA, 2 EA), and three at 19q13 at the kallilkrein-related peptidase 3 (KLK3) locus (two AA, one AA and EA). The KLK3 SNPs also were associated with serum prostate-specific antigen (PSA) levels in AA (P < 0.001) but not in EA. A number of the other SNPs showed some evidence of association but none met study-wide significance levels after adjusting for multiple comparisons. Some replicated GWAS susceptibility SNPs may play a role in CaP aggressiveness. However, like susceptibility, these associations are not consistent between racial groups. Copyright © 2012 Wiley Periodicals, Inc.

Genetic polymorphism and prostate cancer aggressiveness: A case-only study of 1536 GWAS and candidate SNPs in African Americans and European Americans

PubMed Central

Bensen, Jeannette T.; Xu, Zongli; Smith, Gary J.; Mohler, James L.; Fontham, Elizabeth T.H.; Taylor, Jack A.

2012-01-01

BACKGROUND Genome-wide association studies have established a number of replicated single nucleotide polymorphisms (SNPs) for susceptibility to prostate cancer (CaP), but it is unclear whether these susceptibility SNPs are also associated with disease aggressiveness. This study evaluates whether such replication SNPs or other candidate SNPs are associated with CaP aggressiveness in African-American (AA) and European-American (EA) men. METHODS A 1,536 SNP panel which included 34 genome-wide association study (GWAS) replication SNPs, 38 flanking SNPs, a set of ancestry informative markers, and SNPs in candidate genes and other areas was genotyped in 1,060 AA and 1,087 EA men with incident CaP from the North Carolina-Louisiana Prostate Cancer Project (PCaP). Tests for association were conducted using ordinal logistic regression with a log-additive genotype model and a 3-category CaP aggressiveness variable. RESULTS 4 GWAS replication SNPs (rs2660753, rs13254738, rs10090154, rs2735839) and 7 flanking SNPs were associated with CaP aggressiveness (P<0.05) in 3 genomic regions: one at 3p12 (EA), 7 at 8q24 (5 AA, 2 EA), and 3 at 19q13 at the kallilkrein-related peptidase 3 (KLK3) locus (2 AA, 1 AA and EA). The KLK3 SNPs also were associated with serum prostate-specific antigen (PSA) levels in AA (p < 0.001) but not in EA. A number of the other SNPs showed some evidence of association but none met study-wide significance levels after adjusting for multiple comparisons. CONCLUSIONS Some replicated GWAS susceptibility SNPs may play a role in CaP aggressiveness. However, like susceptibility, these associations are not consistent between racial groups. PMID:22549899

Molecular analysis reveals a high mutation frequency in the first untranslated exon of the PPOX gene and largely excludes variegate porphyria in a subset of clinically affected Afrikaner families.

PubMed

Kotze, M J; De Villiers, J N; Groenewald, J Z; Rooney, R N; Loubser, O; Thiart, R; Oosthuizen, C J; van Niekerk, M M; Groenewald, I M; Retief, A E; Warnich, L

1998-10-01

A subset of probands from 11 South African families with clinical and/or biochemical features of variegate porphyria (VP), but without the known protoporphyrinogen oxidase (PPOX) gene defects identified previously in the South African population, were subjected to mutation analysis. Disease-related mutation(s) could not be identified after screening virtually the entire PPOX gene by heteroduplex single-strand conformation polymorphism analysis (HEX-SSCP), although three new sequence variants were detected in exon 1 of the gene in three normal controls. The presence of these single base changes at nucleotide positions 22 (C/G), 27 (C/A) and 127 (C/A), in addition to the known exon 1 polymorphisms I-26 and I-150, indicates that this untranslated region of the PPOX gene is particularly mutation-prone. Furthermore, microsatellite markers flanking the PPOX and alpha-1 antitrypsin (PI) gene, on chromosomes 1 and 14, respectively, were used to assess the probability of involvement of these loci in disease presentation. Common alleles transmitted from affected parent to affected child were determined where possible in the mutation-negative index cases. Allelic frequencies of these alleles were compared to findings in the normal population, but no predominant disease-associated allele could be identified. Co-segregation of a specific haplotype with the disease phenotype could also not be demonstrated in a large Afrikaner family. It is concluded that further studies are warranted to determine the genetic factor(s) underlying the autosomal dominant pattern of inheritance in molecularly uncharacterized cases showing clinical symptoms of an acute porphyria. Copyright 1998 Academic Press.

Candidate gene polymorphisms study between human African trypanosomiasis clinical phenotypes in Guinea.

PubMed

Kaboré, Justin Windingoudi; Ilboudo, Hamidou; Noyes, Harry; Camara, Oumou; Kaboré, Jacques; Camara, Mamadou; Koffi, Mathurin; Lejon, Veerle; Jamonneau, Vincent; MacLeod, Annette; Hertz-Fowler, Christiane; Belem, Adrien Marie Gaston; Matovu, Enock; Bucheton, Bruno; Sidibe, Issa

2017-08-01

Human African trypanosomiasis (HAT), a lethal disease induced by Trypanosoma brucei gambiense, has a range of clinical outcomes in its human host in West Africa: an acute form progressing rapidly to second stage, spontaneous self-cure and individuals able to regulate parasitaemia at very low levels, have all been reported from endemic foci. In order to test if this clinical diversity is influenced by host genetic determinants, the association between candidate gene polymorphisms and HAT outcome was investigated in populations from HAT active foci in Guinea. Samples were collected from 425 individuals; comprising of 232 HAT cases, 79 subjects with long lasting positive and specific serology but negative parasitology and 114 endemic controls. Genotypes of 28 SNPs in eight genes passed quality control and were used for an association analysis. IL6 rs1818879 allele A (p = 0.0001, OR = 0.39, CI95 = [0.24-0.63], BONF = 0.0034) was associated with a lower risk of progressing from latent infection to active disease. MIF rs36086171 allele G seemed to be associated with an increased risk (p = 0.0239, OR = 1.65, CI95 = [1.07-2.53], BONF = 0.6697) but did not remain significant after Bonferroni correction. Similarly MIF rs12483859 C allele seems be associated with latent infections (p = 0.0077, OR = 1.86, CI95 = [1.18-2.95], BONF = 0.2157). We confirmed earlier observations that APOL1 G2 allele (DEL) (p = 0.0011, OR = 2.70, CI95 = [1.49-4.91], BONF = 0.0301) is associated with a higher risk and APOL1 G1 polymorphism (p = 0.0005, OR = 0.45, CI95 = [0.29-0.70], BONF = 0.0129) with a lower risk of developing HAT. No associations were found with other candidate genes. Our data show that host genes are involved in modulating Trypanosoma brucei gambiense infection outcome in infected individuals from Guinea with IL6 rs1818879 being associated with a lower risk of progressing to active HAT. These results enhance our understanding of host-parasite interactions and, ultimately, may lead to the development of new control tools.

SLC24A5 and ASIP as phenotypic predictors in Brazilian population for forensic purposes.

PubMed

Lima, F A; de Araújo Lima, Felícia; Gonçalves, F T; de Toledo Gonçalves, Fernanda; Fridman, C; Fridman, Cintia

2015-07-01

Pigmentation is a variable and complex trait in humans and it is determined by the interaction of environmental factors, age, disease, hormones, exposure to ultraviolet radiation and genetic factors, including pigmentation genes. Many polymorphisms of these genes have been associated with phenotypic diversity of skin, eyes and hair color in homogeneous populations. Phenotype prediction from biological samples using genetic information has benefited forensic area in some countries, leading some criminal investigations. Herein, we evaluated the association between polymorphisms in the genes SLC24A5 (rs1426654) and ASIP (rs6058017) with skin, eyes and hair colors, in 483 healthy individuals from Brazilian population for attainable use in forensic practice. The volunteers answered a questionnaire where they self-reported their skin, eye and hair colors. The polymorphic homozygous genotype of rs1426654∗A and rs6058017∗A in SLC24A5 and ASIP respectively, showed strongest association with fairer skin (OR 47.8; CI 14.1-161.6 and OR 8.6; CI 2.5-29.8); SLC24A5 alone showed associations with blue eyes (OR 20.7; CI 1.2-346.3) and blond hair (OR 26.6; CI 1.5-460.9). Our data showed that polymorphic genotypes (AA), in both genes, are correlated with characteristics of light pigmentation, while the ancestral genotype (GG) is related to darker traits, corroborating with previous studies in European and African populations. These associations show that specific molecular information of an individual may be useful to access some phenotypic features in an attempt to help forensic investigations, not only on crime scene samples but also in cases of face reconstructions in unknown bodies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

The History of African Gene Flow into Southern Europeans, Levantines, and Jews

PubMed Central

Moorjani, Priya; Patterson, Nick; Hirschhorn, Joel N.; Keinan, Alon; Hao, Li; Atzmon, Gil; Burns, Edward; Ostrer, Harry; Price, Alkes L.; Reich, David

2011-01-01

Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%–3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%–15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%–5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas. PMID:21533020

The history of African gene flow into Southern Europeans, Levantines, and Jews.

PubMed

Moorjani, Priya; Patterson, Nick; Hirschhorn, Joel N; Keinan, Alon; Hao, Li; Atzmon, Gil; Burns, Edward; Ostrer, Harry; Price, Alkes L; Reich, David

2011-04-01

Previous genetic studies have suggested a history of sub-Saharan African gene flow into some West Eurasian populations after the initial dispersal out of Africa that occurred at least 45,000 years ago. However, there has been no accurate characterization of the proportion of mixture, or of its date. We analyze genome-wide polymorphism data from about 40 West Eurasian groups to show that almost all Southern Europeans have inherited 1%-3% African ancestry with an average mixture date of around 55 generations ago, consistent with North African gene flow at the end of the Roman Empire and subsequent Arab migrations. Levantine groups harbor 4%-15% African ancestry with an average mixture date of about 32 generations ago, consistent with close political, economic, and cultural links with Egypt in the late middle ages. We also detect 3%-5% sub-Saharan African ancestry in all eight of the diverse Jewish populations that we analyzed. For the Jewish admixture, we obtain an average estimated date of about 72 generations. This may reflect descent of these groups from a common ancestral population that already had some African ancestry prior to the Jewish Diasporas.

A High-Density Admixture Map for Disease Gene Discovery in African Americans

PubMed Central

Smith, Michael W. ; Patterson, Nick ; Lautenberger, James A. ; Truelove, Ann L. ; McDonald, Gavin J. ; Waliszewska, Alicja ; Kessing, Bailey D. ; Malasky, Michael J. ; Scafe, Charles ; Le, Ernest ; De Jager, Philip L. ; Mignault, Andre A. ; Yi, Zeng ; de Thé, Guy ; Essex, Myron ; Sankalé, Jean-Louis ; Moore, Jason H. ; Poku, Kwabena ; Phair, John P. ; Goedert, James J. ; Vlahov, David ; Williams, Scott M. ; Tishkoff, Sarah A. ; Winkler, Cheryl A. ; De La Vega, Francisco M. ; Woodage, Trevor ; Sninsky, John J. ; Hafler, David A. ; Altshuler, David ; Gilbert, Dennis A. ; O’Brien, Stephen J. ; Reich, David 

2004-01-01

Admixture mapping (also known as “mapping by admixture linkage disequilibrium,” or MALD) provides a way of localizing genes that cause disease, in admixed ethnic groups such as African Americans, with ∼100 times fewer markers than are required for whole-genome haplotype scans. However, it has not been possible to perform powerful scans with admixture mapping because the method requires a dense map of validated markers known to have large frequency differences between Europeans and Africans. To create such a map, we screened through databases containing ∼450,000 single-nucleotide polymorphisms (SNPs) for which frequencies had been estimated in African and European population samples. We experimentally confirmed the frequencies of the most promising SNPs in a multiethnic panel of unrelated samples and identified 3,011 as a MALD map (1.2 cM average spacing). We estimate that this map is ∼70% informative in differentiating African versus European origins of chromosomal segments. This map provides a practical and powerful tool, which is freely available without restriction, for screening for disease genes in African American patient cohorts. The map is especially appropriate for those diseases that differ in incidence between the parental African and European populations. PMID:15088270

Predictors of variation in serum IGF1 and IGFBP3 levels in healthy African American and white men.

PubMed

Hoyo, Cathrine; Grubber, Janet; Demark-Wahnefried, Wendy; Lobaugh, Bruce; Jeffreys, Amy S; Grambow, Steven C; Marks, Jeffrey R; Keku, Temitope O; Walther, Phillip J; Schildkraut, Joellen M

2009-07-01

Individual variation in circulating insulinlike growth factor-1 (IGF1) and its major binding protein, insulinlike growth factor binding protein-3 (IGFBP3), have been etiologically linked to several chronic diseases, including some cancers. Factors associated with variation in circulating levels of these peptide hormones remain unclear. Multiple linear regression models were used to determine the extent to which sociodemographic characteristics, lifestyle factors, personal and family history of chronic disease, and common genetic variants, the (CA)n repeat polymorphism in the IGF1 promoter and the IGFBP3-202 A/C polymorphism (rs2854744) predict variation in IGF1 or IGFBP3 serum levels in 33 otherwise healthy African American and 37 white males recruited from Durham Veterans Administration Medical Center. Predictors of serum IGF1, IGFBP3, and the IGF1:IGFBP3 molar ratio varied by race. In African Americans, 17% and 28% of the variation in serum IGF1 and the IGF1:IGFBP3 molar ratio, were explained by cigarette smoking and carrying the IGF1 (CA)19 repeat allele, respectively. Not carrying at least 1 IGF1 (CA)19 repeat allele and a high body mass index explained 8% and 14%, respectively, of the variation IGFBP3 levels. These factors did not predict variation of these peptides in whites. If successfully replicated in larger studies, these findings would add to recent evidence, suggesting known genetic and lifestyle chronic disease risk factors influence IGF1 and IGFBP3 circulating levels differently in African Americans and whites.

Predictors of variation in serum IGFI and IGFBP3 levels in healthy African-American and white men

PubMed Central

Grubber, Janet; Demark-Wahnefried, Wendy; Lobaugh, Bruce; Jeffreys, Amy S.; Grambow, Steven C.; Marks, Jeffrey R.; Keku, Temitope O.; Walther, Phillip J.; Schildkraut, Joellen M.

2010-01-01

Background Individual variation in circulating insulin-like growth factor-I (IGF1) and its major binding protein, insulin-like growth factor binding protein-3 (IGFBP3) have been etiologically linked to several chronic diseases, including some cancers. Factors associated with variation in circulating levels of these peptide hormones remain unclear. Methods Multiple linear regression models were used to determine the extent to which socio-demographic characteristics, lifestyle factors, personal and family history of chronic disease, and common genetic variants, the (CA)n repeat polymorphism in the IGF1 promoter and the IGFBP3 -202 A/C polymorphism (rs2854744) predict variation in IGF1 or IGFBP3 serum levels in 33 otherwise healthy African American and 37 white males recruited from Durham Veterans Administration Medical Center. Results Predictors of serum IGF1, IGFBP3 and the IGF1:IGFBP3 molar ratio varied by race. In African Americans, 17% and 28% of the variation in serum IGF1 and the IGF1:IGFBP3 molar ratio, respectively, was explained by cigarette smoking and carrying the IGF1 (CA)19 repeat allele, respectively. Not carrying at least one IGF1 (CA)19 repeat allele and a high BMI explained 8% and 14%, respectively, of the variation IGFBP3 levels. These factors did not predict variation of these peptides in whites. Conclusion If successfully replicated in larger studies, these findings add to recent evidence suggesting known genetic and lifestyle chronic disease risk factors influence IGF1 and IGFBP3 circulating levels differently in African Americans and whites. PMID:19634593

A SNP test to identify Africanized honeybees via proportion of 'African' ancestry.

PubMed

Chapman, Nadine C; Harpur, Brock A; Lim, Julianne; Rinderer, Thomas E; Allsopp, Michael H; Zayed, Amro; Oldroyd, Benjamin P

2015-11-01

The honeybee, Apis mellifera, is the world's most important pollinator and is ubiquitous in most agricultural ecosystems. Four major evolutionary lineages and at least 24 subspecies are recognized. Commercial populations are mainly derived from subspecies originating in Europe (75-95%). The Africanized honeybee is a New World hybrid of A. m. scutellata from Africa and European subspecies, with the African component making up 50-90% of the genome. Africanized honeybees are considered undesirable for bee-keeping in most countries, due to their extreme defensiveness and poor honey production. The international trade in honeybees is restricted, due in part to bans on the importation of queens (and semen) from countries where Africanized honeybees are extant. Some desirable strains from the United States of America that have been bred for traits such as resistance to the mite Varroa destructor are unfortunately excluded from export to countries such as Australia due to the presence of Africanized honeybees in the USA. This study shows that a panel of 95 single nucleotide polymorphisms, chosen to differentiate between the African, Eastern European and Western European lineages, can detect Africanized honeybees with a high degree of confidence via ancestry assignment. Our panel therefore offers a valuable tool to mitigate the risks of spreading Africanized honeybees across the globe and may enable the resumption of queen and bee semen imports from the Americas. © 2015 John Wiley & Sons Ltd.

Mitochondrial DNA (mtDNA) haplotypes reveal maternal population genetic affinities of Sea Island Gullah-speaking African Americans.

PubMed

McLean, David C; Spruill, Ida; Argyropoulos, George; Page, Grier P; Shriver, Mark D; Garvey, W Timothy

2005-08-01

To better understand the population substructure of African Americans living in coastal South Carolina, we used restriction site polymorphisms and an insertion/deletion in mitochondrial DNA (mtDNA) to construct seven-position haplotypes across 1,395 individuals from Sierra Leone, Africa, from U.S. European Americans, and from the New World African-derived populations of Jamaica, Gullah-speaking African Americans of the South Carolina Sea Islands (Gullahs), African Americans living in Charleston, South Carolina, and West Coast African Americans. Analyses showed a high degree of similarity within the New World African-derived populations, where haplotype frequencies and diversities were similar. Phi-statistics indicated that very little genetic differentiation has occurred within New World African-derived populations, but that there has been significant differentiation of these populations from Sierra Leoneans. Genetic distance estimates indicated a close relationship of Gullahs and Jamaicans with Sierra Leoneans, while African Americans living in Charleston and the West Coast were progressively more distantly related to the Sierra Leoneans. We observed low maternal European American admixture in the Jamaican and Gullah samples (m = 0.020 and 0.064, respectively) that increased sharply in a clinal pattern from Charleston African Americans to West Coast African Americans (m = 0.099 and 0.205, respectively). The appreciably reduced maternal European American admixture noted in the Gullah indicates that the Gullah may be uniquely situated to allow genetic epidemiology studies of complex diseases in African Americans with low European American admixture. (c) 2004 Wiley-Liss, Inc.

Genetic Variation along the Histamine Pathway in Children with Allergic versus Nonallergic Asthma

PubMed Central

Anvari, Sara; Vyhlidal, Carrie A.; Dai, Hongying

2015-01-01

Histamine is an important mediator in the pathogenesis of asthma. Variation in genes along the histamine production, response, and degradation pathway may be important in predicting response to antihistamines. We hypothesize that differences exist among single-nucleotide polymorphisms (SNPs) in genes of the histamine pathway between children with allergic versus nonallergic asthma. Children (7–18 yr of age; n = 202) with asthma were classified as allergic or nonallergic based on allergy skin testing. Genotyping was performed to detect known SNPs (n = 10) among genes (HDC, HNMT, ABP1, HRH1, and HRH4) within the histamine pathway. Chi square tests and Cochran-Armitage Trend were used to identify associations between genetic variants and allergic or nonallergic asthma. Significance was determined by P < 0.05 and false-positive report probability. After correction for race differences in genotype were observed, HRH1-17 TT (6% allergic versus 0% nonallergic; P = 0.04), HNMT-464 TT (41% allergic versus 29% nonallergic; P = 0.04), and HNMT-1639 TT (30% allergic versus 20% nonallergic; P = 0.04) were overrepresented among children with allergic asthma. Genotype differences specifically among the African-American children were also observed: HRH1-17 TT (13% allergic versus 0% nonallergic; P = 0.04) and HNMT-1639 TT (23% allergic versus 3% nonallergic; P = 0.03) genotypes were overrepresented among African-American children with allergic asthma. Our study suggests that genetic variation within the histamine pathway may be associated with an allergic versus nonallergic asthma phenotype. Further studies are needed to determine the functional significance of identified SNPs and their impact on antihistamine response in patients with asthma and allergic disease. PMID:25909280

Genome-Wide Study of Percent Emphysema on Computed Tomography in the General Population. The Multi-Ethnic Study of Atherosclerosis Lung/SNP Health Association Resource Study

PubMed Central

Manichaikul, Ani; Hoffman, Eric A.; Smolonska, Joanna; Gao, Wei; Cho, Michael H.; Baumhauer, Heather; Budoff, Matthew; Austin, John H. M.; Washko, George R.; Carr, J. Jeffrey; Kaufman, Joel D.; Pottinger, Tess; Powell, Charles A.; Wijmenga, Cisca; Zanen, Pieter; Groen, Harry J. M.; Postma, Dirkje S.; Wanner, Adam; Rouhani, Farshid N.; Brantly, Mark L.; Powell, Rhea; Smith, Benjamin M.; Rabinowitz, Dan; Raffel, Leslie J.; Hinckley Stukovsky, Karen D.; Crapo, James D.; Beaty, Terri H.; Hokanson, John E.; Silverman, Edwin K.; Dupuis, Josée; O’Connor, George T.; Boezen, H. Marike; Rich, Stephen S.

2014-01-01

Rationale: Pulmonary emphysema overlaps partially with spirometrically defined chronic obstructive pulmonary disease and is heritable, with moderately high familial clustering. Objectives: To complete a genome-wide association study (GWAS) for the percentage of emphysema-like lung on computed tomography in the Multi-Ethnic Study of Atherosclerosis (MESA) Lung/SNP Health Association Resource (SHARe) Study, a large, population-based cohort in the United States. Methods: We determined percent emphysema and upper-lower lobe ratio in emphysema defined by lung regions less than −950 HU on cardiac scans. Genetic analyses were reported combined across four race/ethnic groups: non-Hispanic white (n = 2,587), African American (n = 2,510), Hispanic (n = 2,113), and Chinese (n = 704) and stratified by race and ethnicity. Measurements and Main Results: Among 7,914 participants, we identified regions at genome-wide significance for percent emphysema in or near SNRPF (rs7957346; P = 2.2 × 10−8) and PPT2 (rs10947233; P = 3.2 × 10−8), both of which replicated in an additional 6,023 individuals of European ancestry. Both single-nucleotide polymorphisms were previously implicated as genes influencing lung function, and analyses including lung function revealed independent associations for percent emphysema. Among Hispanics, we identified a genetic locus for upper-lower lobe ratio near the α-mannosidase–related gene MAN2B1 (rs10411619; P = 1.1 × 10−9; minor allele frequency [MAF], 4.4%). Among Chinese, we identified single-nucleotide polymorphisms associated with upper-lower lobe ratio near DHX15 (rs7698250; P = 1.8 × 10−10; MAF, 2.7%) and MGAT5B (rs7221059; P = 2.7 × 10−8; MAF, 2.6%), which acts on α-linked mannose. Among African Americans, a locus near a third α-mannosidase–related gene, MAN1C1 (rs12130495; P = 9.9 × 10−6; MAF, 13.3%) was associated with percent emphysema. Conclusions: Our results suggest that some genes previously identified as influencing lung function are independently associated with emphysema rather than lung function, and that genes related to α-mannosidase may influence risk of emphysema. PMID:24383474

Genome-wide association study of ancestry-specific TB risk in the South African Coloured population

PubMed Central

Chimusa, Emile R.; Zaitlen, Noah; Daya, Michelle; Möller, Marlo; van Helden, Paul D.; Mulder, Nicola J.; Price, Alkes L.; Hoal, Eileen G.

2014-01-01

The worldwide burden of tuberculosis (TB) remains an enormous problem, and is particularly severe in the admixed South African Coloured (SAC) population residing in the Western Cape. Despite evidence from twin studies suggesting a strong genetic component to TB resistance, only a few loci have been identified to date. In this work, we conduct a genome-wide association study (GWAS), meta-analysis and trans-ethnic fine mapping to attempt the replication of previously identified TB susceptibility loci. Our GWAS results confirm the WT1 chr11 susceptibility locus (rs2057178: odds ratio = 0.62, P = 2.71e−06) previously identified by Thye et al., but fail to replicate previously identified polymorphisms in the TLR8 gene and locus 18q11.2. Our study demonstrates that the genetic contribution to TB risk varies between continental populations, and illustrates the value of including admixed populations in studies of TB risk and other complex phenotypes. Our evaluation of local ancestry based on the real and simulated data demonstrates that case-only admixture mapping is currently impractical in multi-way admixed populations, such as the SAC, due to spurious deviations in average local ancestry generated by current local ancestry inference methods. This study provides insights into identifying disease genes and ancestry-specific disease risk in multi-way admixed populations. PMID:24057671

A Common Polymorphism in SCN2A Predicts General Cognitive Ability through Effects on PFC Physiology.

PubMed

Scult, Matthew A; Trampush, Joey W; Zheng, Fengyu; Conley, Emily Drabant; Lencz, Todd; Malhotra, Anil K; Dickinson, Dwight; Weinberger, Daniel R; Hariri, Ahmad R

2015-09-01

Here we provide novel convergent evidence across three independent cohorts of healthy adults (n = 531), demonstrating that a common polymorphism in the gene encoding the α2 subunit of neuronal voltage-gated type II sodium channels (SCN2A) predicts human general cognitive ability or "g." Using meta-analysis, we demonstrate that the minor T allele of a common polymorphism (rs10174400) in SCN2A is associated with significantly higher "g" independent of gender and age. We further demonstrate using resting-state fMRI data from our discovery cohort (n = 236) that this genetic advantage may be mediated by increased capacity for information processing between the dorsolateral PFC and dorsal ACC, which support higher cognitive functions. Collectively, these findings fill a gap in our understanding of the genetics of general cognitive ability and highlight a specific neural mechanism through which a common polymorphism shapes interindividual variation in "g."

HERC1 polymorphisms: population-specific variations in haplotype composition.

PubMed

Yuasa, Isao; Umetsu, Kazuo; Nishimukai, Hiroaki; Fukumori, Yasuo; Harihara, Shinji; Saitou, Naruya; Jin, Feng; Chattopadhyay, Prasanta K; Henke, Lotte; Henke, Jürgen

2009-08-01

Human HERC1 is one of six HERC proteins and may play an important role in intracellular membrane trafficking. The human HERC1 gene is suggested to have been affected by local positive selection. To assess the global frequency distributions of coding and non-coding single nucleotide polymorphisms (SNPs) in the HERC1 gene, we developed a new simultaneous genotyping method for four SNPs, and applied this method to investigate 1213 individuals from 12 global populations. The results confirmed remarked differences in the allele and haplotype frequencies between East Asian and non-East Asian populations. One of the three common haplotypes observed was found to be characteristic of East Asians, who showed a relatively uniform distribution of haplotypes. Information on haplotypes would be useful for testing the function of polymorphisms in the HERC1 gene. This is the first study to investigate the distribution of HERC1 polymorphisms in various populations. (c) 2009 John Wiley & Sons, Ltd.

Genetic Diversity of Toll-Like Receptors and Immunity to M. leprae Infection

PubMed Central

Hart, Bryan E.; Tapping, Richard I.

2012-01-01

Genetic association studies of leprosy cohorts across the world have identified numerous polymorphisms which alter susceptibility and outcome to infection with Mycobacterium leprae. As expected, many of the polymorphisms reside within genes that encode components of the innate and adaptive immune system. Despite the preponderance of these studies, our understanding of the mechanisms that underlie these genetic associations remains sparse. Toll-like receptors (TLRs) have emerged as an essential family of innate immune pattern recognition receptors which play a pivotal role in host defense against microbes, including pathogenic strains of mycobacteria. This paper will highlight studies which have uncovered the association of specific TLR gene polymorphisms with leprosy or tuberculosis: two important diseases resulting from mycobacterial infection. This analysis will focus on the potential influence these polymorphic variants have on TLR expression and function and how altered TLR recognition or signaling may contribute to successful antimycobacterial immunity. PMID:22529866

The -765G>C polymorphism in the cyclooxygenase-2 gene and digestive system cancer: a meta-analysis.

PubMed

Zhao, Fen; Cao, Yue; Zhu, Hong; Huang, Min; Yi, Cheng; Huang, Ying

2014-01-01

Published data regarding associations between the -765G>C polymorphism in cyclooxygenase-2 (COX-2) gene and digestive system cancer risk have been inconclusive. The aim of this study was to comprehensively evaluate the genetic risk of the -765G>C polymorphism in the COX-2 gene for digestive system cancer. A search was performed in Pubmed, Medline (Ovid), Embase, CNKI, Weipu, Wanfang and CBM databases, covering all studies until Feb 10, 2014. Statistical analysis was performed using Revman5.2. A total of 10,814 cases and 16,174 controls in 38 case-control studies were included in this meta-analysis. The results indicated that C allele carriers (GC+CC) had a 20% increased risk of digestive system cancer when compared with the homozygote GG (odds ratio (OR)=1.20, 95% confidence interval (CI), 1.00-1.44 for GC+CC vs GG). In the subgroup analysis by ethnicity, significant elevated risks were associated with C allele carriers (GC+CC) in Asians (OR = 1.46, 95% CI=1.07-2.01, and p=0.02) and Africans (OR=2.12, 95% CI=1.57-2.87, and p< 0.00001), but not among Caucasians, Americans and mixed groups. For subgroup analysis by cancer type (GC+CC vs GG), significant associations were found between the -765G>C polymorphism and higher risk for gastric cancer (OR=1.64, 95% CI=1.03-2.61, and p=0.04), but not for colorectal cancer, oral cancer, esophageal cancer, and others. Regarding study design (GC+CC vs GG), no significant associations were found in then population-based case-control (PCC), hospital-based case-control (HCC) and family-based case-control (FCC) studies. This meta-analysis suggested that the -765G>C polymorphism of the COX-2 gene is a potential risk factor for digestive system cancer in Asians and Africans and gastric cancer overall.

Population and allelic variation of A-to-I RNA editing in human transcriptomes.

PubMed

Park, Eddie; Guo, Jiguang; Shen, Shihao; Demirdjian, Levon; Wu, Ying Nian; Lin, Lan; Xing, Yi

2017-07-28

A-to-I RNA editing is an important step in RNA processing in which specific adenosines in some RNA molecules are post-transcriptionally modified to inosines. RNA editing has emerged as a widespread mechanism for generating transcriptome diversity. However, there remain significant knowledge gaps about the variation and function of RNA editing. In order to determine the influence of genetic variation on A-to-I RNA editing, we integrate genomic and transcriptomic data from 445 human lymphoblastoid cell lines by combining an RNA editing QTL (edQTL) analysis with an allele-specific RNA editing (ASED) analysis. We identify 1054 RNA editing events associated with cis genetic polymorphisms. Additionally, we find that a subset of these polymorphisms is linked to genome-wide association study signals of complex traits or diseases. Finally, compared to random cis polymorphisms, polymorphisms associated with RNA editing variation are located closer spatially to their respective editing sites and have a more pronounced impact on RNA secondary structure. Our study reveals widespread cis variation in RNA editing among genetically distinct individuals and sheds light on possible phenotypic consequences of such variation on complex traits and diseases.

Gallium plasmonic nanoparticles for label-free DNA and single nucleotide polymorphism sensing

NASA Astrophysics Data System (ADS)

Marín, Antonio García; García-Mendiola, Tania; Bernabeu, Cristina Navio; Hernández, María Jesús; Piqueras, Juan; Pau, Jose Luis; Pariente, Félix; Lorenzo, Encarnación

2016-05-01

A label-free DNA and single nucleotide polymorphism (SNP) sensing method is described. It is based on the use of the pseudodielectric function of gallium plasmonic nanoparticles (GaNPs) deposited on Si (100) substrates under reversal of the polarization handedness condition. Under this condition, the pseudodielectric function is extremely sensitive to changes in the surrounding medium of the nanoparticle surface providing an excellent sensing platform competitive to conventional surface plasmon resonance. DNA sensing has been carried out by immobilizing a thiolated capture probe sequence from Helicobacter pylori onto GaNP/Si substrates; complementary target sequences of Helicobacter pylori can be quantified over the range of 10 pM to 3.0 nM with a detection limit of 6.0 pM and a linear correlation coefficient of R2 = 0.990. The selectivity of the device allows the detection of a single nucleotide polymorphism (SNP) in a specific sequence of Helicobacter pylori, without the need for a hybridization suppressor in solution such as formamide. Furthermore, it also allows the detection of this sequence in the presence of other pathogens, such as Escherichia coli in the sample. The broad applicability of the system was demonstrated by the detection of a specific gene mutation directly associated with cystic fibrosis in large genomic DNA isolated from blood cells.A label-free DNA and single nucleotide polymorphism (SNP) sensing method is described. It is based on the use of the pseudodielectric function of gallium plasmonic nanoparticles (GaNPs) deposited on Si (100) substrates under reversal of the polarization handedness condition. Under this condition, the pseudodielectric function is extremely sensitive to changes in the surrounding medium of the nanoparticle surface providing an excellent sensing platform competitive to conventional surface plasmon resonance. DNA sensing has been carried out by immobilizing a thiolated capture probe sequence from Helicobacter pylori onto GaNP/Si substrates; complementary target sequences of Helicobacter pylori can be quantified over the range of 10 pM to 3.0 nM with a detection limit of 6.0 pM and a linear correlation coefficient of R2 = 0.990. The selectivity of the device allows the detection of a single nucleotide polymorphism (SNP) in a specific sequence of Helicobacter pylori, without the need for a hybridization suppressor in solution such as formamide. Furthermore, it also allows the detection of this sequence in the presence of other pathogens, such as Escherichia coli in the sample. The broad applicability of the system was demonstrated by the detection of a specific gene mutation directly associated with cystic fibrosis in large genomic DNA isolated from blood cells. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00926c

Tailoring Nutritional Advice for Mexicans Based on Prevalence Profiles of Diet-Related Adaptive Gene Polymorphisms

PubMed Central

Ojeda-Granados, Claudia; Panduro, Arturo; Gonzalez-Aldaco, Karina; Sepulveda-Villegas, Maricruz; Rivera-Iñiguez, Ingrid

2017-01-01

Diet-related adaptive gene (DRAG) polymorphisms identified in specific populations are associated with chronic disorders in carriers of the adaptive alleles due to changes in dietary and lifestyle patterns in recent times. Mexico’s population is comprised of Amerindians (AM) and Mestizos who have variable AM, European (EUR) and African genetic ancestry and an increased risk of nutrition-related chronic diseases. Nutritional advice based on the Mexican genome and the traditional food culture is needed to develop preventive and therapeutic strategies. Therefore, we aimed to provide a prevalence profile of several DRAG polymorphisms in the Mexican population, including Central West (CW) Mexico subpopulations. Geographic heat maps were built using ArcGIS10 (Esri, Redlands, CA, USA) software, based on the published data of the MTHFR C677T (rs1801133), ABCA1 Arg230Cys (rs9282541), APOE T388C (rs429358)/C526T (rs7412), LCT C-13910T (rs4988235) polymorphisms and AMY1 copy number variation (CNV). Also, new data obtained by allelic discrimination-real-time polymerase chain reaction (RT-PCR) assays for the MTHFR, ABCA1, and APOE polymorphisms as well as the AMY1 CNV in the CW Mexico subpopulations with different proportions of AM and EUR ancestry were included. In the CW region, the highest frequency of the MTHFR 677T, ABCA1 230C and APOE ε4 adaptive alleles was observed in the AM groups, followed by Mestizos with intermediate AM ancestry. The LCT-13910T allele frequency was highest in Mestizos-EUR but extremely low in AM, while the AMY1 diploid copy number was 6.82 ± 3.3 copies. Overall, the heat maps showed a heterogeneous distribution of the DRAG polymorphisms, in which the AM groups revealed the highest frequencies of the adaptive alleles followed by Mestizos. Given these genetic differences, genome-based nutritional advice should be tailored in a regionalized and individualized manner according to the available foods and Mexican traditional food culture that may lead to a healthier dietary pattern. PMID:29125573

Scrutinizing human MHC polymorphism: Supertype analysis using Poisson-Boltzmann electrostatics and clustering.

PubMed

Mumtaz, Shahzad; Nabney, Ian T; Flower, Darren R

2017-10-01

Peptide-binding MHC proteins are thought the most variable across the human population; the extreme MHC polymorphism observed is functionally important and results from constrained divergent evolution. MHCs have vital functions in immunology and homeostasis: cell surface MHC class I molecules report cell status to CD8+ T cells, NKT cells and NK cells, thus playing key roles in pathogen defence, as well as mediating smell recognition, mate choice, Adverse Drug Reactions, and transplantation rejection. MHC peptide specificity falls into several supertypes exhibiting commonality of binding. It seems likely that other supertypes exist relevant to other functions. Since comprehensive experimental characterization is intractable, structure-based bioinformatics is the only viable solution. We modelled functional MHC proteins by homology and used calculated Poisson-Boltzmann electrostatics projected from the top surface of the MHC as multi-dimensional descriptors, analysing them using state-of-the-art dimensionality reduction techniques and clustering algorithms. We were able to recover the 3 MHC loci as separate clusters and identify clear sub-groups within them, vindicating unequivocally our choice of both data representation and clustering strategy. We expect this approach to make a profound contribution to the study of MHC polymorphism and its functional consequences, and, by extension, other burgeoning structural systems, such as GPCRs. Copyright © 2017 Elsevier Inc. All rights reserved.

The catechol-O-methyltransferase gene (COMT) and cognitive function from childhood through adolescence

PubMed Central

Gaysina, Darya; Xu, Man K.; Barnett, Jennifer H.; Croudace, Tim J.; Wong, Andrew; Richards, Marcus; Jones, Peter B.

2013-01-01

Genetic variation in the catechol-O-methyltransferase gene (COMT) can influence cognitive function, and this effect may depend on developmental stage. Using a large representative British birth cohort, we investigated the effect of COMT on cognitive function (verbal and non-verbal) at ages 8 and 15 years taking into account the possible modifying effect of pubertal stage. Five functional COMT polymorphisms, rs6269, rs4818, rs4680, rs737865 and rs165599 were analysed. Associations between COMT polymorphisms and cognition were tested using regression and latent variable structural equation modelling (SEM). Before correction for multiple testing, COMT rs737865 showed association with reading comprehension, verbal ability and global cognition at age 15 years in pubescent boys only. Although there was some evidence for age- and sex-specific effects of the COMT rs737865 none remained significant after correction for multiple testing. Further studies are necessary in order to make firmer conclusions. PMID:23178897

The Influence of DAT1, COMT, and BDNF Genetic Polymorphisms on Total and Subregional Hippocampal Volumes in Early Onset Heavy Cannabis Users

PubMed Central

Batalla, Albert; Lorenzetti, Valentina; Chye, Yann; Yücel, Murat; Soriano-Mas, Carles; Bhattacharyya, Sagnik; Torrens, Marta; Crippa, José A.S.; Martín-Santos, Rocío

2018-01-01

Abstract Introduction: Hippocampal neuroanatomy is affected by genetic variations in dopaminergic candidate genes and environmental insults, such as early onset of chronic cannabis exposure. Here, we examine how hippocampal total and subregional volumes are affected by cannabis use and functional polymorphisms of dopamine-relevant genes, including the catechol-O-methyltransferase (COMT), dopamine transporter (DAT1), and the brain-derived neurotrophic factor (BDNF) genes. Material and Methods: We manually traced total hippocampal volumes and automatically segmented hippocampal subregions using high-resolution MRI images, and performed COMT, DAT1, and BDNF genotyping in 59 male Caucasian young adults aged 18–30 years. These included 30 chronic cannabis users with early-onset (regular use at <16 years) and 29 age-, education-, and intelligence-matched controls. Results: Cannabis use and dopaminergic gene polymorphism had both distinct and interactive effects on the hippocampus. We found emerging alterations of hippocampal total and specific subregional volumes in cannabis users relative to controls (i.e., CA1, CA2/3, and CA4), and associations between cannabis use levels and total and specific subregional volumes. Furthermore, total hippocampal volume and the fissure subregion were affected by cannabis×DAT1 polymorphism (i.e., 9/9R and in 10/10R alleles), reflecting high and low levels of dopamine availability. Conclusion: These findings suggest that cannabis exposure alters the normal relationship between DAT1 polymorphism and the anatomy of total and subregional hippocampal volumes, and that specific hippocampal subregions may be particularly affected. PMID:29404409

The Influence of DAT1, COMT, and BDNF Genetic Polymorphisms on Total and Subregional Hippocampal Volumes in Early Onset Heavy Cannabis Users.

PubMed

Batalla, Albert; Lorenzetti, Valentina; Chye, Yann; Yücel, Murat; Soriano-Mas, Carles; Bhattacharyya, Sagnik; Torrens, Marta; Crippa, José A S; Martín-Santos, Rocío

2018-01-01

Introduction: Hippocampal neuroanatomy is affected by genetic variations in dopaminergic candidate genes and environmental insults, such as early onset of chronic cannabis exposure. Here, we examine how hippocampal total and subregional volumes are affected by cannabis use and functional polymorphisms of dopamine-relevant genes, including the catechol-O-methyltransferase (COMT), dopamine transporter (DAT1), and the brain-derived neurotrophic factor (BDNF) genes. Material and Methods: We manually traced total hippocampal volumes and automatically segmented hippocampal subregions using high-resolution MRI images, and performed COMT, DAT1, and BDNF genotyping in 59 male Caucasian young adults aged 18-30 years. These included 30 chronic cannabis users with early-onset (regular use at <16 years) and 29 age-, education-, and intelligence-matched controls. Results: Cannabis use and dopaminergic gene polymorphism had both distinct and interactive effects on the hippocampus. We found emerging alterations of hippocampal total and specific subregional volumes in cannabis users relative to controls (i.e., CA1, CA2/3, and CA4), and associations between cannabis use levels and total and specific subregional volumes. Furthermore, total hippocampal volume and the fissure subregion were affected by cannabis×DAT1 polymorphism (i.e., 9/9R and in 10/10R alleles), reflecting high and low levels of dopamine availability. Conclusion: These findings suggest that cannabis exposure alters the normal relationship between DAT1 polymorphism and the anatomy of total and subregional hippocampal volumes, and that specific hippocampal subregions may be particularly affected.

Genetic diversity of 38 insertion-deletion polymorphisms in Jewish populations.

PubMed

Ferragut, J F; Pereira, R; Castro, J A; Ramon, C; Nogueiro, I; Amorim, A; Picornell, A

2016-03-01

Population genetic data of 38 non-coding biallelic autosomal indels are reported for 466 individuals, representing six populations with Jewish ancestry (Ashkenazim, Mizrahim, Sephardim, North African, Chuetas and Bragança crypto-Jews). Intra-population diversity and forensic parameters values showed that this set of indels was highly informative for forensic applications in the Jewish populations studied. Genetic distance analysis demonstrated that this set of markers efficiently separates populations from different continents, but does not seem effective for molecular anthropology studies in Mediterranean region. Finally, it is important to highlight that although the genetic distances between Jewish populations were small, significant differences were observed for Chuetas and Bragança Jews, and therefore, specific databases must be used for these populations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Surface-functionalized cockle shell–based calcium carbonate aragonite polymorph as a drug nanocarrier

PubMed Central

Mohd Abd Ghafar, Syairah Liyana; Hussein, Mohd Zobir; Rukayadi, Yaya; Abu Bakar Zakaria, Md Zuki

2017-01-01

Calcium carbonate aragonite polymorph nanoparticles derived from cockle shells were prepared using surface functionalization method followed by purification steps. Size, morphology, and surface properties of the nanoparticles were characterized using transmission electron microscopy, field emission scanning electron microscopy, dynamic light scattering, zetasizer, X-ray powder diffraction, and Fourier transform infrared spectrometry techniques. The potential of surface-functionalized calcium carbonate aragonite polymorph nanoparticle as a drug-delivery agent were assessed through in vitro drug-loading test and drug-release test. Transmission electron microscopy, field emission scanning electron microscopy, and particle size distribution analyses revealed that size, morphology, and surface characterization had been improved after surface functionalization process. Zeta potential of the nanoparticles was found to be increased, thereby demonstrating better dispersion among the nanoparticles. Purification techniques showed a further improvement in the overall distribution of nanoparticles toward more refined size ranges <100 nm, which specifically favored drug-delivery applications. The purity of the aragonite phase and their chemical analyses were verified by X-ray powder diffraction and Fourier transform infrared spectrometry studies. In vitro biological response of hFOB 1.19 osteoblast cells showed that surface functionalization could improve the cytotoxicity of cockle shell–based calcium carbonate aragonite nanocarrier. The sample was also sensitive to pH changes and demonstrated good abilities to load and sustain in vitro drug. This study thus indicates that calcium carbonate aragonite polymorph nanoparticles derived from cockle shells, a natural biomaterial, with modified surface characteristics are promising and can be applied as efficient carriers for drug delivery. PMID:28572724

Ancestry-Adjusted Vitamin D Metabolite Concentrations in Association With Cytochrome P450 3A Polymorphisms.

PubMed

Wilson, Robin Taylor; Masters, Loren D; Barnholtz-Sloan, Jill S; Salzberg, Anna C; Hartman, Terryl J

2018-04-01

We investigated the association between genetic polymorphisms in cytochrome P450 (CYP2R1, CYP24A1, and the CYP3A family) with nonsummer plasma concentrations of vitamin D metabolites (25-hydroxyvitamin D3 (25(OH)D3) and proportion 24,25-dihydroxyvitamin D3 (24,25(OH)2D3)) among healthy individuals of sub-Saharan African and European ancestry, matched on age (within 5 years; n = 188 in each ancestral group), in central suburban Pennsylvania (2006-2009). Vitamin D metabolites were measured using high-performance liquid chromatography with tandem mass spectrometry. Paired multiple regression and adjusted least-squares mean analyses were used to test for associations between genotype and log-transformed metabolite concentrations, adjusted for age, sex, proportion of West-African genetic ancestry, body mass index, oral contraceptive (OC) use, tanning bed use, vitamin D intake, days from summer solstice, time of day of blood draw, and isoforms of the vitamin D receptor (VDR) and vitamin D binding protein. Polymorphisms in CYP2R1, CYP3A43, vitamin D binding protein, and genetic ancestry proportion remained associated with plasma 25(OH)D3 after adjustment. Only CYP3A43 and VDR polymorphisms were associated with proportion 24,25(OH)2D3. Magnitudes of association with 25(OH)D3 were similar for CYP3A43, tanning bed use, and OC use. Significant least-squares mean interactions (CYP2R1/OC use (P = 0.030) and CYP3A43/VDR (P = 0.013)) were identified. A CYP3A43 genotype, previously implicated in cancer, is strongly associated with biomarkers of vitamin D metabolism. Interactive associations should be further investigated.

Interleukin-6 Gene Polymorphisms, Dietary Fat Intake, Obesity and Serum Lipid Concentrations in Black and White South African Women

PubMed Central

Joffe, Yael T.; van der Merwe, Lize; Evans, Juliet; Collins, Malcolm; Lambert, Estelle V.; September, Alison; Goedecke, Julia H.

2014-01-01

This study investigated interactions between dietary fat intake and IL-6 polymorphisms on obesity and serum lipids in black and white South African (SA) women. Normal-weight and obese, black and white women underwent measurements of body composition, serum lipids and dietary fat intake, and were genotyped for the IL-6 −174 G>C, IVS3 +281 G>T and IVS4 +869 A>G polymorphisms. In black women the IVS4 +869 G allele was associated with greater adiposity, and with increasing dietary fat intake adiposity increased in the IVS3 +281 GT+GG and IVS4 +869 AA or AG genotypes. In white women, with increasing omega-3 (n-3) intake and decreasing n-6:n-3 ratio, body mass index (BMI) decreased in those with the −174 C allele, IVS3 +281 T allele and IVS4 +869 AG genotype. In the white women, those with the IVS3 +281 T allele had lower triglycerides. Further, with increasing n-3 polyunsaturated fatty acid (PUFA); triglyceride and total cholesterol:high-density lipoprotein cholesterol (T-C:HDL-C) ratio decreased in those with the −174 C allele. In black women, with increasing total fat intake, triglycerides and T-C:HDL-C ratio increased in those with the IVS4 +869 G allele. This study is the first to show that dietary fat intake modulates the relationship between the IL-6 −174 G>C, IVS3 +281 G>T and IVS4 +869 A>G polymorphisms on obesity and serum lipids in black and white SA women. PMID:24962479

Genetic variation in a compound short tandem repeat/Alu haplotype system at the SB19.3 locus: properties and interpretation.

PubMed

Gaspar, Paulo; Seixas, Susana; Rocha, Jorge

2004-04-01

The genetic variation at a compound nonrecombining haplotype system, consisting of the previously reported SB19.3 Alu insertion polymorphism and a newly identified adjacent short tandem repeat (STR), was studied in population samples from Portugal and São Tomé (Gulf of Guinea, West Africa). Age estimates based on the linked microsatellite variation suggest that the Alu insertion occurred about 190,000 years ago. In accordance with the global patterns of distribution of human genetic variation, the highest haplotype diversity was found in the African sample. This excess in African diversity was due to both a substantial reduction in heterozygosity at the Alu polymorphism and a lower STR variability associated with the predominant Alu insertion allele in the Portuguese sample. The high level of interpopulation differentiation observed at the Alu locus (F(ST) = 0.43) was interpreted under alternative selective and demographic scenarios. The need for compatibility between patterns of variation at the STR and Alu loci could be used to restrict the range of selection coefficients in selection-driven genetic hitchhiking frameworks and to favor demographic scenarios dominated by larger pre-expansion African population sizes. Taken together, the data show that the SB19.3 Alu-STR system is an informative marker that can be included in more extended batteries of compound haplotypes used in human evolutionary studies.

HLA polymorphisms in Cabo Verde and Guiné-Bissau inferred from sequence-based typing.

PubMed

Spínola, Hélder; Bruges-Armas, Jácome; Middleton, Derek; Brehm, António

2005-10-01

Human leukocyte antigen (HLA)-A, -B, and -DRB1 polymorphisms were examined in the Cabo Verde and Guiné-Bissau populations. The data were obtained at high-resolution level, using sequence-based typing. The most frequent alleles in each locus was: A*020101 (16.7% in Guiné-Bissau and 13.5% in Cabo Verde), B*350101 (14.4% in Guiné-Bissau and 13.2% in Cabo Verde), DRB1*1304 (19.6% in Guiné-Bissau), and DRB1*1101 (10.1% in Cabo Verde). The predominant three loci haplotype in Guiné-Bissau was A*2301-B*1503-DRB1*1101 (4.6%) and in Cabo Verde was A*3002-B*350101-DRB1*1001 (2.8%), exclusive to northwestern islands (5.6%) and absent in Guiné-Bissau. The present study corroborates historic sources and other genetic studies that say Cabo Verde were populated not only by Africans but also by Europeans. Haplotypes and dendrogram analysis shows a Caucasian genetic influence in today's gene pool of Cabo Verdeans. Haplotypes and allele frequencies present a differential distribution between southeastern and northwestern Cabo Verde islands, which could be the result of different genetic influences, founder effect, or bottlenecks. Dendrograms and principal coordinates analysis show that Guineans are more similar to North Africans than other HLA-studied sub-Saharans, probably from ancient and recent genetic contacts with other peoples, namely East Africans.

Diversity and evolutionary patterns of immune genes in free-ranging Namibian leopards (Panthera pardus pardus).

PubMed

Castro-Prieto, Aines; Wachter, Bettina; Melzheimer, Joerg; Thalwitzer, Susanne; Sommer, Simone

2011-01-01

The genes of the major histocompatibility complex (MHC) are a key component of the mammalian immune system and have become important molecular markers for fitness-related genetic variation in wildlife populations. Currently, no information about the MHC sequence variation and constitution in African leopards exists. In this study, we isolated and characterized genetic variation at the adaptively most important region of MHC class I and MHC class II-DRB genes in 25 free-ranging African leopards from Namibia and investigated the mechanisms that generate and maintain MHC polymorphism in the species. Using single-stranded conformation polymorphism analysis and direct sequencing, we detected 6 MHC class I and 6 MHC class II-DRB sequences, which likely correspond to at least 3 MHC class I and 3 MHC class II-DRB loci. Amino acid sequence variation in both MHC classes was higher or similar in comparison to other reported felids. We found signatures of positive selection shaping the diversity of MHC class I and MHC class II-DRB loci during the evolutionary history of the species. A comparison of MHC class I and MHC class II-DRB sequences of the leopard to those of other felids revealed a trans-species mode of evolution. In addition, the evolutionary relationships of MHC class II-DRB sequences between African and Asian leopard subspecies are discussed.

Reduced-median-network analysis of complete mitochondrial DNA coding-region sequences for the major African, Asian, and European haplogroups.

PubMed

Herrnstadt, Corinna; Elson, Joanna L; Fahy, Eoin; Preston, Gwen; Turnbull, Douglass M; Anderson, Christen; Ghosh, Soumitra S; Olefsky, Jerrold M; Beal, M Flint; Davis, Robert E; Howell, Neil

2002-05-01

The evolution of the human mitochondrial genome is characterized by the emergence of ethnically distinct lineages or haplogroups. Nine European, seven Asian (including Native American), and three African mitochondrial DNA (mtDNA) haplogroups have been identified previously on the basis of the presence or absence of a relatively small number of restriction-enzyme recognition sites or on the basis of nucleotide sequences of the D-loop region. We have used reduced-median-network approaches to analyze 560 complete European, Asian, and African mtDNA coding-region sequences from unrelated individuals to develop a more complete understanding of sequence diversity both within and between haplogroups. A total of 497 haplogroup-associated polymorphisms were identified, 323 (65%) of which were associated with one haplogroup and 174 (35%) of which were associated with two or more haplogroups. Approximately one-half of these polymorphisms are reported for the first time here. Our results confirm and substantially extend the phylogenetic relationships among mitochondrial genomes described elsewhere from the major human ethnic groups. Another important result is that there were numerous instances both of parallel mutations at the same site and of reversion (i.e., homoplasy). It is likely that homoplasy in the coding region will confound evolutionary analysis of small sequence sets. By a linkage-disequilibrium approach, additional evidence for the absence of human mtDNA recombination is presented here.

The Brain-Derived Neurotrophic Factor Val66Met Polymorphism Moderates an Effect of Physical Activity on Working Memory Performance

PubMed Central

Erickson, Kirk I.; Banducci, Sarah E.; Weinstein, Andrea M.; MacDonald, Angus W.; Ferrell, Robert E.; Halder, Indrani; Flory, Janine D.; Manuck, Stephen B.

2014-01-01

Physical activity enhances cognitive performance, yet individual variability in its effectiveness limits its widespread therapeutic application. Genetic differences might be one source of this variation. For example, carriers of the methionine-specifying (Met) allele of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism have reduced secretion of BDNF and poorer memory, yet physical activity increases BDNF levels. To determine whether the BDNF polymorphism moderated an association of physical activity with cognitive functioning among 1,032 midlife volunteers (mean age = 44.59 years), we evaluated participants’ performance on a battery of tests assessing memory, learning, and executive processes, and evaluated their physical activity with the Paffenbarger Physical Activity Questionnaire. BDNF genotype interacted robustly with physical activity to affect working memory, but not other areas of cognitive functioning. In particular, greater levels of physical activity offset a deleterious effect of the Met allele on working memory performance. These findings suggest that physical activity can modulate domain-specific genetic (BDNF) effects on cognition. PMID:23907543

[Gene geography of Chile: regional distribution of American, European and African genetic contributions].

PubMed

Fuentes, Macarena; Pulgar, Iván; Gallo, Carla; Bortolini, María-Cátira; Canizales-Quinteros, Samuel; Bedoya, Gabriel; González-José, Rolando; Ruiz-Linares, Andrés; Rothhammer, Francisco

2014-03-01

The geographical distribution of genes plays a key role in genetic epidemiology. The Chilean population has three major stem groups (Native American, European and African). To estimate the regional rate of American, European and African admixture of the Chilean population. Forty single nucleotide polymorphisms (SNP´s) which exhibit substantially different frequencies between Amerindian populations (ancestry-informative markers or AIM´s), were genotyped in a sample of 923 Chilean participants to estimate individual genetic ancestry. The American, European and African individual average admixture estimates for the 15 Chilean Regions were relatively homogeneous and not statistically different. However, higher American components were found in northern and southern Chile and higher European components were found in central Chile. A negative correlation between African admixture and latitude was observed. On the average, American and European genetic contributions were similar and significantly higher than the African contribution. Weighted mean American, European and African genetic contributions of 44.34% ± 3 9%, 51.85% ± 5.44% and 3.81% ± 0.45%, were estimated. Fifty two percent of subjects harbor African genes. Individuals with Aymara and Mapuche surnames have an American admixture of 58.64% and 68.33%, respectively. Half of the Chilean population harbors African genes. Participants with Aymara and Mapuche surnames had a higher American genetic contribution than the general Chilean population. These results confirm the usefulness of surnames as a first approximation to determine genetic ancestry.

Assessing interethnic admixture using an X-linked insertion-deletion multiplex.

PubMed

Ribeiro-Rodrigues, Elzemar Martins; dos Santos, Ney Pereira Carneiro; dos Santos, Andrea Kely Campos Ribeiro; Pereira, Rui; Amorim, António; Gusmão, Leonor; Zago, Marco Antonio; dos Santos, Sidney Emanuel Batista

2009-01-01

In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (approximately 41%), followed by European (approximately 32%) and African (approximately 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations.

MTHFR 677C --> T genotype disrupts prefrontal function in schizophrenia through an interaction with COMT 158Val --> Met.

PubMed

Roffman, Joshua L; Gollub, Randy L; Calhoun, Vince D; Wassink, Thomas H; Weiss, Anthony P; Ho, Beng C; White, Tonya; Clark, Vincent P; Fries, Jill; Andreasen, Nancy C; Goff, Donald C; Manoach, Dara S

2008-11-11

Understanding how risk genes cumulatively impair brain function in schizophrenia could provide critical insights into its pathophysiology. Working memory impairment in schizophrenia has been associated with abnormal dopamine signaling in the prefrontal cortex, which is likely under complex genetic control. The catechol-O-methyltransferase (COMT) 158Val --> Met polymorphism (rs4680), which affects the availability of prefrontal dopamine signaling, consistently stratifies prefrontal activation during working memory performance. However, the low-dopamine COMT 158Val allele does not confer increased risk for schizophrenia, and its effects on prefrontal function are not specific to the disorder. In the setting of other genetic variants influencing prefrontal dopamine signaling, COMT 158Val --> Met genotype may exert disease-specific effects. A second polymorphism, methylenetetrahydrofolate reductase (MTHFR) 677C --> T (rs1801133), has been associated with overall schizophrenia risk and executive function impairment in patients, and may influence dopamine signaling through mechanisms upstream of COMT effects. We found that the hypofunctional 677T variant was associated with decreased working memory load-dependent activation in the prefrontal and insular cortices in 79 schizophrenia patients, but not in 75 demographically matched healthy controls. Further, significant MTHFR x COMT genotype interactions were observed, which differed by diagnostic group: Reduced prefrontal activation was associated with the 677T and 158Val alleles in patients, but with 677C/C and 158Met/Met genotype in controls. These findings are consistent with epistatic effects of the COMT and MTHFR polymorphisms on prefrontal dopamine signaling, and suggest that in schizophrenia patients, the MTHFR 677T allele exacerbates prefrontal dopamine deficiency. The findings also suggest the importance of weighing COMT effects on prefrontal function within the context of MTHFR genotype.

Sousse: extreme genetic heterogeneity in North Africa.

PubMed

Fadhlaoui-Zid, Karima; Garcia-Bertrand, Ralph; Alfonso-Sánchez, Miguel A; Zemni, Ramzi; Benammar-Elgaaied, Amel; Herrera, Rene J

2015-01-01

The male genetic landscape of the territory currently known as Tunisia is hampered by the scarcity of data, especially from cosmopolitan areas such as the coastal city of Sousse. In order to alleviate this lacuna, 220 males from Sousse were examined, for the first time, for more than 50 Y-chromosome single-nucleotide polymorphisms (Y-SNPs) markers and compared with 3099 individuals from key geographically targeted locations in North Africa, Europe and the Near East. The paternal lineages observed belong to a common set of Y haplogroups previously described in North Africa. In addition to the prominent autochthonous North African E-M81 haplogroup which is exclusively represented by its subclade E-M183 (44.55% of Y-chromosomes), a number of Near Eastern Neolithic lineages including E-M78, J-M267 and J-M172 account for 39% of the Y-chromosomes detected. Principal component analysis based on haplogroup frequencies, multidimensional scaling based on Rst genetic distances and analyses of molecular variance using both Y-chromosome short tandem repeat haplotypes and Y-SNP haplogroup data revealed that the Tunisian and North African groups, as a whole, are intra- and inter-specific diverse with Sousse being highly heterogeneous.

Assessing Mild Cognitive Impairment among Older African Americans

PubMed Central

Gamaldo, Alyssa A.; Allaire, Jason C.; Sims, Regina C.; Whitfield, Keith E.

2009-01-01

OBJECTIVES To examine the frequency of MCI in African American older adults. The study also plans to explore the specific cognitive domains of impairment as well as whether there are differences in demographics, health, and cognitive performance between MCI and normal participants. DESIGN Cross-sectional. SETTING Independent-living sample of urban dwelling elders in Baltimore, Maryland. PARTICIPANTS The sample consisted of 554 subjects ranging in age from 50 to 95 (mean = 68.79 ± 9.60). MEASUREMENTS Socio-demographics and health were assessed. Several cognitive measures were administered to assess inductive reasoning, declarative memory, perceptual speed, working memory, executive functioning, language, global cognitive functioning. RESULTS Approximately 22% of participants were considered MCI (i.e. 18% non-amnestic vs. 4% amnestic). A majority of the non-amnestic MCI participants had impairment in one cognitive domain, particularly language and executive function. Individuals classified as non-amnestic MCI were significantly older and had more years of education than normal individuals. The MCI groups were not significantly different than cognitively normal individuals on health factors. Individuals classified as MCI performed significantly worse on global cognitive measures as well as across specific cognitive domains than cognitively normal individuals. CONCLUSION This study demonstrates that impairment in a non-memory domain may be an early indicator of cognitive impairment, particularly among African Americans. PMID:20069588

Development and characterization of 13 polymorphic microsatellite loci for Cryptolepsis sanguinolenta, an African antimalarial plant

USDA-ARS?s Scientific Manuscript database

Cryptolepsis sanguinolenta is an herbaceous perennial plant indigenous to West and Central Africa. The roots are harvested and widely used in the preparation of herbal decoctions to treat malaria. The process of harvesting wild grown roots is unsustainable, and the plant is becoming more difficult t...

Alu Insertions and Genetic Diversity: A Preliminary Investigation by an Undergraduate Bioinformatics Class

ERIC Educational Resources Information Center

Elwess, Nancy L.; Duprey, Stephen L.; Harney, Lindesay A.; Langman, Jessie E.; Marino, Tara C.; Martinez, Carolina; McKeon, Lauren L.; Moss, Chantel I. E.; Myrie, Sasha S.; Taylor, Luke Ryan

2008-01-01

"Alu"-insertion polymorphisms were used by an undergraduate Bioinformatics class to study how these insertion sites could be the basis for an investigation in human population genetics. Based on the students' investigation, both allele and genotype "Alu" frequencies were determined for African-American and Japanese populations as well as a…

Behavior-Specific Influences for Physical Activity Among African American Women.

PubMed

Jackson, Hope; Yates, Bernice C; Blanchard, Shirley; Zimmerman, Lani M; Hudson, Diane; Pozehl, Bunny

2016-08-01

The purpose of this study was to describe physical activity (PA) behaviors and physical functioning of prehypertensive and Stage I hypertensive African American Women (AAW) and to examine the relationships between PA behavior, physical functioning, personal factors, and behavior-specific influences. Pender's Health Promotion Model was the conceptual framework for the study. A cross-sectional design and convenience sample were used. The PA domain where the greatest amount of time was spent was in work-related activity, followed by household, leisure time, and transportation activity. Personal factors most strongly correlated to lower PA were greater body mass index and waist circumference. AAW perceived moderate barriers to PA and minimal family and friend social support for PA. Future interventions need to focus on removing barriers to and improving social support for PA among AAW. © The Author(s) 2016.

How does mother-to-child transmission of HIV differ among African populations? Lessons from MBL2 genetic variation in Zimbabweans.

PubMed

Mhandire, Kudakwashe; Pharo, Gavin; Kandawasvika, Gwendolene Q; Duri, Kerina; Swart, Marelize; Stray-Pedersen, Babill; Dandara, Collet

2014-07-01

Mannose binding lectin (MBL) is a pathogen pattern recognition protein involved in antimicrobial activities. Variation in MBL2 gene has been extensively implicated in differential outcomes of infectious diseases in studies conducted outside Africa, but virtually very little is known on the role of this candidate gene in the African continent. We investigated human genetic variations in MBL2 in a Zimbabwean pediatric population and their putative associations with HIV infection in perinatally exposed children. One hundred and four children aged 7 to 9 years comprising 68 perinatally exposed to HIV (32 who were born infected and 36 who were uninfected) and 36 unexposed controls were recruited. DNA samples were genotyped for MBL2 polymorphisms using PCR-RFLP and sequencing. HIV infected children had markedly variable and significantly lower mean height (p=0.03) and weight (p=0.005) when compared to the uninfected children. Using all samples, frequencies for MBL2 genetic variants for the Zimbabwean population were calculated. Twelve single nucleotide polymorphisms were observed and minor alleles occurred with the following frequencies: -550C>G (G: 0.02), -435G>A (A: 0.08), -428A>C (C: 0.39), -394A>G (A: 0.39), -328AGAGAA ins/del (AGAGAA ins: 0.44), -245G>A (A: 0.05), -221C>G (C: 0.12), -111A>T (T: 0.10), -70C>T (C: 0.46), +4C>T (C: 0.45), novel -595G>A (A: 0.02), and 170G>A (0.24). We found that the MBL2 +4T variant displayed a trend for association with reduced risk of HIV transmission from mother-to-child but the remaining vast majority of the genetic markers did not show a significant association. We conclude (1) the MBL2 gene is highly polymorphic in the Zimbabwean population, and (2) MBL2 genetic variation does not appear to play a major role in influencing the risk of mother-to-child HIV transmission in our study sample. These observations contest the hitherto significant role of this candidate gene for HIV transmission from mother-to-child in non-African populations and thus, further speak to the limits of extrapolating genomic association studies directly to the African populations from studies conducted elsewhere. It is hoped that more OMICS research in a diverse set of African countries can shed further light on the putative role (or the lack thereof ) of this candidate gene in HIV transmission in the continent, a major global health burden in Africa.

The shaping of modern human immune systems by multiregional admixture with archaic humans.

PubMed

Abi-Rached, Laurent; Jobin, Matthew J; Kulkarni, Subhash; McWhinnie, Alasdair; Dalva, Klara; Gragert, Loren; Babrzadeh, Farbod; Gharizadeh, Baback; Luo, Ma; Plummer, Francis A; Kimani, Joshua; Carrington, Mary; Middleton, Derek; Rajalingam, Raja; Beksac, Meral; Marsh, Steven G E; Maiers, Martin; Guethlein, Lisbeth A; Tavoularis, Sofia; Little, Ann-Margaret; Green, Richard E; Norman, Paul J; Parham, Peter

2011-10-07

Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic human leukocyte antigen (HLA) class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems.

The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans

PubMed Central

Abi-Rached, Laurent; Jobin, Matthew J; Kulkarni, Subhash; McWhinnie, Alasdair; Dalva, Klara; Gragert, Loren; Babrzadeh, Farbod; Gharizadeh, Baback; Luo, Ma; Plummer, Francis A; Kimani, Joshua; Carrington, Mary; Middleton, Derek; Rajalingam, Raja; Beksac, Meral; Marsh, Steven GE; Maiers, Martin; Guethlein, Lisbeth A; Tavoularis, Sofia; Little, Ann-Margaret; Green, Richard E; Norman, Paul J; Parham, Peter

2013-01-01

Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic HLA class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems. PMID:21868630

Thorough analysis of unorthodox ABO deletions called by the 1000 Genomes project.

PubMed

Möller, M; Hellberg, Å; Olsson, M L

2018-02-01

ABO remains the clinically most important blood group system, but despite earlier extensive research, significant findings are still being made. The vast majority of catalogued ABO null alleles are based on the c.261delG polymorphism. Apart from c.802G>A, other mechanisms for O alleles are rare. While analysing the data set from the 1000 Genomes (1000G) project, we encountered two previously uncharacterized deletions, which needed further exploration. The Erythrogene database, complemented with bioinformatics software, was used to analyse ABO in 2504 individuals from 1000G. DNA samples from selected 1000G donors and African blood donors were examined by allele-specific PCR and Sanger sequencing to characterize predicted deletions. A 5821-bp deletion encompassing exons 5-7 was called in twenty 1000G individuals, predominantly Africans. This allele was confirmed and its exact deletion point defined by bioinformatic analyses and in vitro experiments. A PCR assay was developed, and screening of African samples revealed three donors heterozygous for this deletion, which was thereby phenotypically established as an O allele. Analysis of upstream genetic markers indicated an ancestral origin from ABO*O.01.02. We estimate this deletion as the 3rd most common mechanism behind O alleles. A 24-bp deletion was called in nine individuals and showed greater diversity regarding ethnic distribution and allelic background. It could neither be confirmed by in silico nor in vitro experiments. A previously uncharacterized ABO deletion among Africans was comprehensively mapped and a genotyping strategy devised. The false prediction of another deletion emphasizes the need for cautious interpretation of NGS data and calls for strict validation routines. © 2017 International Society of Blood Transfusion.

A Novel Variant in the Platelet Endothelial Aggregation Receptor-1 Gene is Associated with Increased Platelet Aggregabili

PubMed Central

Herrera-Galeano, J. Enrique; Becker, Diane M.; Wilson, Alexander F.; Yanek, Lisa R.; Bray, Paul; Vaidya, Dhananjay; Faraday, Nauder; Becker, Lewis C

2009-01-01

Objective: Platelet endothelial aggregation receptor-1 (PEAR1) is a recently identified platelet transmembrane protein that becomes activated by platelet contact. We looked for novel genetic variants in PEAR1 and studied their association with agonist-induced native platelet aggregation and with aspirin's inhibitory effect on platelets. Methods and Results: We genotyped PEAR1 for 10 single nucleotide polymorphisms (SNPs), selected for optimal gene coverage at a density of 4kb, in 1486 apparently healthy individuals from two generations of families with premature CAD. Subjects had a mean age of 45 years; 62% were white and 38% African American. Platelet aggregation to collagen, epinephrine, and ADP was measured in platelet rich plasma, at baseline and after 2 weeks of aspirin (ASA, 81 mg/day), and genotype-phenotype associations were examined separately by ethnicity using multivariable generalized linear models adjusted for covariates. The C allele of SNP rs2768759 [A/C], located in the promoter region of the gene, was common in whites and uncommon in African Americans (allele frequency 70.2% vs 17.7%). The C allele was generally associated in both ethnic groups with increased aggregation of native platelets to each agonist. Following ASA, the associations were stronger and more consistent, and remained significant when post ASA aggregation was adjusted for baseline aggregation, consistent with a relationship between the C allele and reduced platelet responsiveness to ASA. The PEAR1 SNP explained up to 6.9% of the locus specific genetic variance in African Americans and up to 2.5% of the genetic variance in whites following ASA. Conclusion: PEAR1 appears to play an important role in agonist-induced platelet aggregation and in the response to ASA in both whites and African Americans. PMID:18511696

The Influence of HIV on the Evolution of Mycobacterium tuberculosis

PubMed Central

Brites, Daniela; Stucki, David; Evans, Joanna C.; Seldon, Ronnett; Heekes, Alexa; Mulder, Nicola; Nicol, Mark; Oni, Tolu; Mizrahi, Valerie; Warner, Digby F.; Parkhill, Julian; Gagneux, Sebastien; Martin, Darren P.; Wilkinson, Robert J.

2017-01-01

Abstract HIV significantly affects the immunological environment during tuberculosis coinfection, and therefore may influence the selective landscape upon which M. tuberculosis evolves. To test this hypothesis whole genome sequences were determined for 169 South African M. tuberculosis strains from HIV-1 coinfected and uninfected individuals and analyzed using two Bayesian codon-model based selection analysis approaches: FUBAR which was used to detect persistent positive and negative selection (selection respectively favoring and disfavoring nonsynonymous substitutions); and MEDS which was used to detect episodic directional selection specifically favoring nonsynonymous substitutions within HIV-1 infected individuals. Among the 25,251 polymorphic codon sites analyzed, FUBAR revealed that 189-fold more were detectably evolving under persistent negative selection than were evolving under persistent positive selection. Three specific codon sites within the genes celA2b, katG, and cyp138 were identified by MEDS as displaying significant evidence of evolving under directional selection influenced by HIV-1 coinfection. All three genes encode proteins that may indirectly interact with human proteins that, in turn, interact functionally with HIV proteins. Unexpectedly, epitope encoding regions were enriched for sites displaying weak evidence of directional selection influenced by HIV-1. Although the low degree of genetic diversity observed in our M. tuberculosis data set means that these results should be interpreted carefully, the effects of HIV-1 on epitope evolution in M. tuberculosis may have implications for the design of M. tuberculosis vaccines that are intended for use in populations with high HIV-1 infection rates. PMID:28369607

Involvement of Serotonin Transporter Gene Polymorphisms (5-HTT) in Impulsive Behavior in the Japanese Population

PubMed Central

Nomura, Michio; Kaneko, Masayuki; Okuma, Yasunobu; Nomura, Jun; Kusumi, Ichiro; Koyama, Tsukasa; Nomura, Yasuyuki

2015-01-01

The serotonergic pathway has been implicated in the pathogenesis of impulsivity, and sensitivity to aversive outcomes may be linked to serotonin (5-HT) levels. Polymorphisms in the gene that encodes the serotonin transporter (5-HTT), which have differential effects on the level of serotonin transmission, display alternate responses to aversive stimuli. However, recent studies have shown that 5-HT does not affect motor function, which suggests that the functioning of the serotonin-transporter-linked polymorphic region (5-HTTLPR) does not directly affect the behavioral regulatory process itself, but instead exerts an effect via the evaluation of the potential risk associated with particular behavioral outputs. The aim of the present study was to examine the effect of specific 5-HTTLPR genotypes on the motor regulatory process, as observed during a Go/Nogo punishment feedback task. 5-HTT gene-linked promoter polymorphisms were analyzed by polymerase chain reaction, using lymphocytes from 61 healthy Japanese volunteers. Impulsivity was defined as the number of commission errors (responding when one should not) made during a Go/Nogo task. We found that the s/s genotype group made fewer impulsive responses, specifically under aversive conditions for committing such errors, compared to those in the s/l group, without affecting overall motor inhibition. These results suggest that 5-HTTLPRs do not directly affect the behavioral regulatory process itself, but may instead exert an effect on the evaluation of potential risk. The results also indicate that under such aversive conditions, decreased expression of 5-HTT may promote motor inhibitory control. PMID:25775400

New Insights on the Risk for Cardiovascular Disease in African Americans: The Role of Added Sugars

PubMed Central

Saab, Karim R.; Kendrick, Jessica; Yracheta, Joseph M.; Lanaspa, Miguel A.; Pollard, Maisha

2015-01-01

African Americans are at increased risk for cardiovascular and metabolic diseases, including obesity, high BP, diabetes, CKD, myocardial infarction, and stroke. Here we summarize the current risks and provide an overview of the underlying risk factors that may account for these associations. By reviewing the relationship between cardiovascular and renal diseases and the African-American population during the early 20th century, the historic and recent associations of African heritage with cardiovascular disease, and modern population genetics, it is possible to assemble strong hypotheses for the primary underlying mechanisms driving the increased frequency of disease in African Americans. Our studies suggest that underlying genetic mechanisms may be responsible for the increased frequency of high BP and kidney disease in African Americans, with particular emphasis on the role of APOL1 polymorphisms in causing kidney disease. In contrast, the Western diet, particularly the relatively high intake of fructose-containing sugars and sweetened beverages, appears to be the dominant force driving the increased risk of diabetes, obesity, and downstream complications. Given that intake of added sugars is a remediable risk factor, we recommend clinical trials to examine the reduction of sweetened beverages as a primary means for reducing cardiovascular risk in African Americans. PMID:25090991

Serum protein polymorphisms in a Liberian population.

PubMed

Willcox, M; Beckman, G; Beckman, L

1986-01-01

Serum protein variations were studied in a Liberian population living in Buchanan town. Of the alpha 1-antitrypsin genes only M1 and M3 were polymorphic. The frequencies of the haptoglobin and Gc genes were in accordance with earlier known estimates in African populations. There was, however, a relatively low frequency of Hp 0 which may be related to the low malarial parasite prevalence in this group. The transferrin C2 gene was found in a significantly lower frequency among Liberians compared to European and Asiatic populations. A new transferrin variant was observed by isoelectric focusing. This variant could not be identified with conventional starch or polyacrylamide electrophoresis.

Development and characterization of genomic SSR markers in Cynodon transvaalensis Burtt-Davy.

PubMed

Tan, Chengcheng; Wu, Yanqi; Taliaferro, Charles M; Bell, Greg E; Martin, Dennis L; Smith, Mike W

2014-08-01

Simple sequence repeat (SSR) markers are a major molecular tool for genetic and genomic research that have been extensively developed and used in major crops. However, few are available in African bermudagrass (Cynodon transvaalensis Burtt-Davy), an economically important warm-season turfgrass species. African bermudagrass is mainly used for hybridizations with common bermudagrass [C. dactylon var. dactylon (L.) Pers.] in the development of superior interspecific hybrid turfgrass cultivars. Accordingly, the major objective of this study was to develop and characterize a large set of SSR markers. Genomic DNA of C. transvaalensis '4200TN 24-2' from an Oklahoma State University (OSU) turf nursery was extracted for construction of four SSR genomic libraries enriched with [CA](n), [GA](n), [AAG](n), and [AAT](n) as core repeat motifs. A total of 3,064 clones were sequenced at the OSU core facility. The sequences were categorized into singletons and contiguous sequences to exclude redundancy. From the two sequence categories, 1,795 SSR loci were identified. After excluding duplicate SSRs by comparison with previously developed SSR markers using a nucleotide basic local alignment tool, 1,426 unique primer pairs (PPs) were designed. Out of the 1,426 designed PPs, 981 (68.8 %) amplified alleles of the expected size in the donor DNA. Polymorphisms of the SSR PPs tested in eight C. transvaalensis plants were 93 % polymorphic with 544 markers effective in all genotypes. Inheritance of the SSRs was examined in six F(1) progeny of African parents 'T577' × 'Uganda', indicating 917 markers amplified heritable alleles. The SSR markers developed in the study are the first large set of co-dominant markers in African bermudagrass and should be highly valuable for molecular and traditional breeding research.

Single nucleotide polymorphism coverage and inference of N-acetyltransferase-2 acetylator phenotypes in wordwide population groups.

PubMed

Suarez-Kurtz, Guilherme; Fuchshuber-Moraes, Mateus; Struchiner, Claudio J; Parra, Esteban J

2016-08-01

Several algorithms have been proposed to reduce the genotyping effort and cost, while retaining the accuracy of N-acetyltransferase-2 (NAT2) phenotype prediction. Data from the 1000 Genomes (1KG) project and an admixed cohort of Black Brazilians were used to assess the accuracy of NAT2 phenotype prediction using algorithms based on paired single nucleotide polymorphisms (SNPs) (rs1041983 and rs1801280) or a tag SNP (rs1495741). NAT2 haplotypes comprising SNPs rs1801279, rs1041983, rs1801280, rs1799929, rs1799930, rs1208 and rs1799931 were assigned according to the arylamine N-acetyltransferases database. Contingency tables were used to visualize the agreement between the NAT2 acetylator phenotypes on the basis of these haplotypes versus phenotypes inferred by the prediction algorithms. The paired and tag SNP algorithms provided more than 96% agreement with the 7-SNP derived phenotypes in Europeans, East Asians, South Asians and Admixed Americans, but discordance of phenotype prediction occurred in 30.2 and 24.8% 1KG Africans and in 14.4 and 18.6% Black Brazilians, respectively. Paired SNP panel misclassification occurs in carriers of NATs haplotypes *13A (282T alone), *12B (282T and 803G), *6B (590A alone) and *14A (191A alone), whereas haplotype *14, defined by the 191A allele, is the major culprit of misclassification by the tag allele. Both the paired SNP and the tag SNP algorithms may be used, with economy of scale, to infer NAT2 acetylator phenotypes, including the ultra-slow phenotype, in European, East Asian, South Asian and American populations represented in the 1KG cohort. Both algorithms, however, perform poorly in populations of predominant African descent, including admixed African-Americans, African Caribbeans and Black Brazilians.

Region 2 of 8q24 is associated with the risk of aggressive prostate cancer in Caribbean men of African descent from Guadeloupe (French West Indies)

PubMed Central

Cancel-Tassin, Geraldine; Romana, Marc; Gaffory, Cecile; Blanchet, Pascal; Cussenot, Olivier; Multigner, Luc

2015-01-01

Multiple regions of the genome have been associated with the risk of prostate cancer in Caucasians, particularly including several polymorphisms located at 8q24. Region 2 of 8q24 has been repeatedly found to be associated with the risk of prostate cancer among men of African descent, although one study performed in the Caribbean island of Jamaica did not report this finding. In this study, the single nucleotide polymorphism rs16901979, located in region 2 of 8q24, was genotyped in 498 cases of histologically confirmed prostate cancer and 541 controls from the French Caribbean islands of Guadeloupe, where the population is largely of African descent. The AA genotype and the A allele at rs16901979 were associated with elevated risks of prostate cancer (odds ratios [ORs] = 1.84, 95% confidence interval [95% CI] = 1.26–2.69, P = 0.002 and OR = 1.36, 95% CI = 1.13–1.64, P = 0.001, respectively). Following stratification of the patients by disease aggressiveness, as defined by the Gleason score, the pooled genotypes AC + AA were associated with a higher risk of a Gleason score ≥7 at diagnosis (OR = 1.79, 95% CI = 1.17–2.73, P = 0.007). In summary, the A allele at rs16901979 was associated with the risk of prostate cancer in the Caribbean population of Guadeloupe, confirming its involvement in populations of African descent. Moreover, our study provides the first evidence of an association between this variant and the risk of aggressive prostate cancer. PMID:25130587

LPA and PLG sequence variation and kringle IV-2 copy number in two populations.

PubMed

Crawford, Dana C; Peng, Ze; Cheng, Jan-Fang; Boffelli, Dario; Ahearn, Magdalena; Nguyen, Dan; Shaffer, Tristan; Yi, Qian; Livingston, Robert J; Rieder, Mark J; Nickerson, Deborah A

2008-01-01

Lp(a) levels have long been recognized as a potential risk factor for coronary heart disease that is almost completely under genetic control. Much of the genetics impacting Lp(a) levels has been attributed to the highly polymorphic LPA kringle IV-2 copy number variant, and most of the variance in Lp(a) levels in populations of European-descent is inversely correlated with kringle IV copy number. However, less of the variance is explained in African-descent populations for the same structural variation. African-descent populations have, on average, higher levels of Lp(a), suggesting other genetic factors contribute to Lp(a) level variability across populations. To identify potential cis-acting factors, we re-sequenced the gene LPA for single nucleotide polymorphism (SNP) discovery in 23 European-Americans and 24 African-Americans. We also re- sequenced the neighboring gene plasminogen (PLG) and genotyped the kringle IV copy number variant in the same reference samples. These data are the most comprehensive description of sequence variation in LPA and its relationship with the kringle IV copy number variant. With these data, we demonstrate that only a fraction of LPA sequence diversity has been previously documented. Also, we identify several high frequency SNPs present in the African-American sample but absent in the European-American sample. Finally, we show that SNPs within PLG are not in linkage disequilibrium with SNPs in LPA, and we show that kringle IV copy number variation is not in linkage disequilibrium with either LPA or PLG SNPs. Together, these data suggest that LPA SNPs could independently contribute to Lp(a) levels in the general population. Copyright (c) 2008 S. Karger AG, Basel.

Quantification of GC-biased gene conversion in the human genome

PubMed Central

Glémin, Sylvain; Arndt, Peter F.; Messer, Philipp W.; Petrov, Dmitri; Galtier, Nicolas; Duret, Laurent

2015-01-01

Much evidence indicates that GC-biased gene conversion (gBGC) has a major impact on the evolution of mammalian genomes. However, a detailed quantification of the process is still lacking. The strength of gBGC can be measured from the analysis of derived allele frequency spectra (DAF), but this approach is sensitive to a number of confounding factors. In particular, we show by simulations that the inference is pervasively affected by polymorphism polarization errors and by spatial heterogeneity in gBGC strength. We propose a new general method to quantify gBGC from DAF spectra, incorporating polarization errors, taking spatial heterogeneity into account, and jointly estimating mutation bias. Applying it to human polymorphism data from the 1000 Genomes Project, we show that the strength of gBGC does not differ between hypermutable CpG sites and non-CpG sites, suggesting that in humans gBGC is not caused by the base-excision repair machinery. Genome-wide, the intensity of gBGC is in the nearly neutral area. However, given that recombination occurs primarily within recombination hotspots, 1%–2% of the human genome is subject to strong gBGC. On average, gBGC is stronger in African than in non-African populations, reflecting differences in effective population sizes. However, due to more heterogeneous recombination landscapes, the fraction of the genome affected by strong gBGC is larger in non-African than in African populations. Given that the location of recombination hotspots evolves very rapidly, our analysis predicts that, in the long term, a large fraction of the genome is affected by short episodes of strong gBGC. PMID:25995268

Genetic factors influencing bone mineral content in a black South African population.

PubMed

May, Andrew; Pettifor, John M; Norris, Shane A; Ramsay, Michèle; Lombard, Zané

2013-11-01

Bone mass differs according to ethnic classification, with individuals of African ancestry attaining the highest measurements across numerous skeletal sites. Elevated bone mass is even maintained in those individuals exposed to adverse environmental factors, suggesting a prominent genetic effect that may have clinical or therapeutic value. Using a candidate gene approach, we investigated associations of six candidate genes (ESR1, TNFRSF11A, TNFRSF11B, TNFSF11, SOST and SPP1) with bone mass at the hip and lumbar spine amongst pre-pubertal black South African children (mean age 10.6 years) who formed part of the longitudinal Birth to Twenty cohort. 151 black children were genotyped at 366 polymorphic loci, including 112 previously associated and 254 tagging single nucleotide polymorphisms (SNPs). Linear regression was used to highlight significant associations whilst adjusting for height, weight, sex and bone area. Twenty-seven markers (8 previously associated and 19 tag SNPs; P < 0.05) were found to be associated with either femoral neck (18) or lumbar spine (9) bone mineral content. These signals were derived from three genes, namely ESR1 (17), TNFRSF11B (9) and SPP1 (1). One marker (rs2485209) maintained its association with the femoral neck after correction for multiple testing (P = 0.038). When compared to results amongst Caucasian adults, we detected differences with respect to associated skeletal sites. Allele frequencies and linkage disequilibrium patterns were also significantly different between populations. Hence, our results support the existence of a strong genetic effect acting at the femoral neck in black South African children, whilst simultaneously highlighting possible causes that account for inter-ethnic bone mass diversity.

High-Resolution Analysis of Human Y-Chromosome Variation Shows a Sharp Discontinuity and Limited Gene Flow between Northwestern Africa and the Iberian Peninsula

PubMed Central

Bosch, Elena; Calafell, Francesc; Comas, David; Oefner, Peter J.; Underhill, Peter A.; Bertranpetit, Jaume

2001-01-01

In the present study we have analyzed 44 Y-chromosome biallelic polymorphisms in population samples from northwestern (NW) Africa and the Iberian Peninsula, which allowed us to place each chromosome unequivocally in a phylogenetic tree based on >150 polymorphisms. The most striking results are that contemporary NW African and Iberian populations were found to have originated from distinctly different patrilineages and that the Strait of Gibraltar seems to have acted as a strong (although not complete) barrier to gene flow. In NW African populations, an Upper Paleolithic colonization that probably had its origin in eastern Africa contributed 75% of the current gene pool. In comparison, ∼78% of contemporary Iberian Y chromosomes originated in an Upper Paleolithic expansion from western Asia, along the northern rim of the Mediterranean basin. Smaller contributions to these gene pools (constituting 13% of Y chromosomes in NW Africa and 10% of Y chromosomes in Iberia) came from the Middle East during the Neolithic and, during subsequent gene flow, from Sub-Saharan to NW Africa. Finally, bidirectional gene flow across the Strait of Gibraltar has been detected: the genetic contribution of European Y chromosomes to the NW African gene pool is estimated at 4%, and NW African populations may have contributed 7% of Iberian Y chromosomes. The Islamic rule of Spain, which began in a.d. 711 and lasted almost 8 centuries, left only a minor contribution to the current Iberian Y-chromosome pool. The high-resolution analysis of the Y chromosome allows us to separate successive migratory components and to precisely quantify each historical layer. PMID:11254456

Polymorphic SVA retrotransposons at four loci and their association with classical HLA class I alleles in Japanese, Caucasians and African Americans.

PubMed

Kulski, Jerzy K; Shigenari, Atsuko; Inoko, Hidetoshi

2010-04-01

Polymorphic insertion frequencies of the retrotransposons known as the "SVA" elements were investigated at four loci in the MHC class I genomic region to determine their allele and haplotype frequencies and associations with the HLA-A, -B or -C genes for 100 Japanese, 100 African Americans, 174 Australian Caucasians and 66 reference cell lines obtained from different ethnic groups. The SVA insertions representing different subfamily members varied in frequency between none for SVA-HF in Japanese and 65% for SVA-HB in Caucasians or African Americans with significant differences in frequencies between the three populations at least at three loci. The SVA loci were in Hardy-Weinberg equilibrium except for the SVA-HA locus which deviated significantly in African Americans and Caucasians possibly because of a genomic deletion of this locus in individuals with the HLA-A*24 allele. Strong linkage disequilibria and high percentage associations between the human leucocyte antigen (HLA) class I gene alleles and some of the SVA insertions were detected in all three populations in spite of significant frequency differences for the SVA and HLA class I alleles between the three populations. The highest percentage associations (>86%) were between SVA-HB and HLA-B*08, -B*27, -B*37 to -B*41, -B*52 and -B*53; SVA-HC and HLA-B*07; SVA-HA and HLA-A*03, -A*11 and -A*30; and SVA-HF and HLA-A*03 and HLA-B*47. From pairwise associations in the three populations and the homozygous cell line results, it was possible to deduce the SVA and HLA class I allelic combinations (haplotypes), population differences and the identity by descent of several common HLA-A allelic lineages.

Rapid identification of apolipoprotein E genotypes by high-resolution melting analysis in Chinese Han and African Fang populations.

PubMed

Zhan, Xiu-Hui; Zha, Guang-Cai; Jiao, Ji-Wei; Yang, Li-Ye; Zhan, Xiao-Fen; Chen, Jiang-Tao; Xie, Dong-DE; Eyi, Urbano Monsuy; Matesa, Rocio Apicante; Obono, Maximo Miko Ondo; Ehapo, Carlos Sala; Wei, Er-Jia; Zheng, Yu-Zhong; Yang, Hui; Lin, Min

2015-02-01

Apolipoprotein E (APOE) gene polymorphism can affect APOE gene transcription, serum lipid levels and repair of tissue damage, which could place individuals at serious risk of cardiovascular disease or certain infectious diseases. Recently, high-resolution melting (HRM) analysis was reported to be a simple, inexpensive, accurate and sensitive method for the genotyping or/and scanning of rare mutations. For this reason, an HRM analysis was used in the present study for APOE genotyping in the Southern Chinese Han and African Fang populations. A total of 100 healthy Southern Chinese Han and 175 healthy African Fang individuals attended the study. Polymerase chain reaction-DNA sequencing was used as a reference method for the genotyping of these samples. The six APOE genotypes could all be rapidly and efficiently identified by HRM analysis, and 100% concordance was found between the HRM analysis and the reference method. The allele frequencies of APOE in the Southern Chinese Han population were 7.0, 87.5 and 5.5% for ɛ2, ɛ3 and ɛ4, respectively. In the African Fang population, the allele frequencies of APOE were 24.3, 65.7 and 10.0% for ɛ2, ɛ3 and ɛ4, respectively. A statistically significant difference was found between the allele frequencies between the populations (P<0.05). In conclusion, the present study revealed the molecular characterization of APOE gene polymorphism in the Han population from the Chaozhou region of Southern China and the Fang population from Equatorial Guinea. The findings of the study indicated that HRM analysis could be used as an accurate and sensitive method for the rapid screening and identification of APOE genotypes in prospective clinical and population genetic analyses.

Meiotic recombination generates rich diversity in NK cell receptor genes, alleles, and haplotypes

PubMed Central

Norman, Paul J.; Abi-Rached, Laurent; Gendzekhadze, Ketevan; Hammond, John A.; Moesta, Achim K.; Sharma, Deepti; Graef, Thorsten; McQueen, Karina L.; Guethlein, Lisbeth A.; Carrington, Christine V.F.; Chandanayingyong, Dasdayanee; Chang, Yih-Hsin; Crespí, Catalina; Saruhan-Direskeneli, Güher; Hameed, Kamran; Kamkamidze, Giorgi; Koram, Kwadwo A.; Layrisse, Zulay; Matamoros, Nuria; Milà, Joan; Park, Myoung Hee; Pitchappan, Ramasamy M.; Ramdath, D. Dan; Shiau, Ming-Yuh; Stephens, Henry A.F.; Struik, Siske; Tyan, Dolly; Verity, David H.; Vaughan, Robert W.; Davis, Ronald W.; Fraser, Patricia A.; Riley, Eleanor M.; Ronaghi, Mostafa; Parham, Peter

2009-01-01

Natural killer (NK) cells contribute to the essential functions of innate immunity and reproduction. Various genes encode NK cell receptors that recognize the major histocompatibility complex (MHC) Class I molecules expressed by other cells. For primate NK cells, the killer-cell immunoglobulin-like receptors (KIR) are a variable and rapidly evolving family of MHC Class I receptors. Studied here is KIR3DL1/S1, which encodes receptors for highly polymorphic human HLA-A and -B and comprises three ancient allelic lineages that have been preserved by balancing selection throughout human evolution. While the 3DS1 lineage of activating receptors has been conserved, the two 3DL1 lineages of inhibitory receptors were diversified through inter-lineage recombination with each other and with 3DS1. Prominent targets for recombination were D0-domain polymorphisms, which modulate enhancer function, and dimorphism at position 283 in the D2 domain, which influences inhibitory function. In African populations, unequal crossing over between the 3DL1 and 3DL2 genes produced a deleted KIR haplotype in which the telomeric “half” was reduced to a single fusion gene with functional properties distinct from its 3DL1 and 3DL2 parents. Conversely, in Eurasian populations, duplication of the KIR3DL1/S1 locus by unequal crossing over has enabled individuals to carry and express alleles of all three KIR3DL1/S1 lineages. These results demonstrate how meiotic recombination combines with an ancient, preserved diversity to create new KIR phenotypes upon which natural selection acts. A consequence of such recombination is to blur the distinction between alleles and loci in the rapidly evolving human KIR gene family. PMID:19411600

Plasminogen activator inhibitor I 4G/5G polymorphism in neonatal respiratory distress syndrome.

PubMed

Armangil, Didem; Yurdakök, Murat; Okur, Hamza; Gürgey, Aytemiz

2011-08-01

Fibrin monomers inhibit surfactant function. 4G/5G insertion/deletion polymorphism plays an important role in the regulation of plasminogen activator inhibitor 1 (PAI-1) gene expression. To examine the genotype distribution of PAI-1 polymorphism in 60 infants with respiratory distress syndrome (RDS) and 53 controls, an allele-specific polymerase chain reaction (PCR) was used. The proportion of 4G/4G, 4G/5G, and 5G/5G genotypes did not differ statistically between the RDS and control groups (P > .05). Having PAI-1 4G/4G genotype polymorphism appears to increase the risk of RDS (odds ratio [OR] =1.5; 95% confidence interval [CI], 0.5-4.3), although it was not statistically significant. No relation was found between the PAI-1 4G/5G polymorphisms and RDS, but there was an increased risk associated with the 4G variant of the PAI-1 gene. We believe that our findings of increased 4G allele of the PAI-1 gene in infants with RDS would also help to clarify the pathogenesis of RDS.

USP38, FREM3, SDC1, DDC, and LOC727982 Gene Polymorphisms and Differential Susceptibility to Severe Malaria in Tanzania.

PubMed

Manjurano, Alphaxard; Sepúlveda, Nuno; Nadjm, Behzad; Mtove, George; Wangai, Hannah; Maxwell, Caroline; Olomi, Raimos; Reyburn, Hugh; Drakeley, Christopher J; Riley, Eleanor M; Clark, Taane G

2015-10-01

Populations exposed to Plasmodium falciparum infection develop genetic mechanisms of protection against severe malarial disease. Despite decades of genetic epidemiological research, the sickle cell trait (HbAS) sickle cell polymorphism, ABO blood group, and other hemoglobinopathies remain the few major determinants in severe malaria to be replicated across different African populations and study designs. Within a case-control study in a region of high transmission in Tanzania (n = 983), we investigated the role of 40 new loci identified in recent genome-wide studies. In 32 loci passing quality control procedures, we found polymorphisms in USP38, FREM3, SDC1, DDC, and LOC727982 genes to be putatively associated with differential susceptibility to severe malaria. Established candidates explained 7.4% of variation in severe malaria risk (HbAS polymorphism, 6.3%; α-thalassemia, 0.3%; ABO group, 0.3%; and glucose-6-phosphate dehydrogenase deficiency, 0.5%) and the new polymorphisms, another 4.3%. The regions encompassing the loci identified are promising targets for the design of future treatment and control interventions. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America.

Assessment of the relationship between ACE I/D gene polymorphism and renal allograft survival.

PubMed

Yang, Chun-Hua; Lu, Yi; Chen, Xue-Xia; Xian, Wen-Feng; Tu, Wei-Feng; Li, Hong-Yan

2015-12-01

The relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism and renal allograft survival after renal transplantation from the published reports are still debatable. This study was performed to evaluate the relationship between the ACE I/D gene polymorphism and renal allograft survival after renal transplantation using meta-analysis. Eligible studies were identified from PubMed and Cochrane Library on 1 November 2014, and eligible studies were recruited and synthesized using a meta-analysis methodology. Twelve investigations were included in this meta-analysis for the assessment of the relationship between the ACE I/D gene polymorphism and renal allograft survival. In this meta-analysis, the ACE I/D gene polymorphism was not associated with renal allograft survival after renal transplantation for overall populations, Caucasians, Brazilians and Africans. Interestingly, the ACE D allele and DD genotype were associated with renal allograft survival after renal transplantation in the Asian population. ACE D allele and DD genotype were associated with renal allograft survival after renal transplantation in the Asian population. However, more studies should be performed to confirm this association. © The Author(s) 2015.

Association of genome-wide variation with the risk of incident heart failure in adults of European and African ancestry: a prospective meta-analysis from the cohorts for heart and aging research in genomic epidemiology (CHARGE) consortium.

PubMed

Smith, Nicholas L; Felix, Janine F; Morrison, Alanna C; Demissie, Serkalem; Glazer, Nicole L; Loehr, Laura R; Cupples, L Adrienne; Dehghan, Abbas; Lumley, Thomas; Rosamond, Wayne D; Lieb, Wolfgang; Rivadeneira, Fernando; Bis, Joshua C; Folsom, Aaron R; Benjamin, Emelia; Aulchenko, Yurii S; Haritunians, Talin; Couper, David; Murabito, Joanne; Wang, Ying A; Stricker, Bruno H; Gottdiener, John S; Chang, Patricia P; Wang, Thomas J; Rice, Kenneth M; Hofman, Albert; Heckbert, Susan R; Fox, Ervin R; O'Donnell, Christopher J; Uitterlinden, Andre G; Rotter, Jerome I; Willerson, James T; Levy, Daniel; van Duijn, Cornelia M; Psaty, Bruce M; Witteman, Jacqueline C M; Boerwinkle, Eric; Vasan, Ramachandran S

2010-06-01

Although genetic factors contribute to the onset of heart failure (HF), no large-scale genome-wide investigation of HF risk has been published to date. We have investigated the association of 2,478,304 single-nucleotide polymorphisms with incident HF by meta-analyzing data from 4 community-based prospective cohorts: the Atherosclerosis Risk in Communities Study, the Cardiovascular Health Study, the Framingham Heart Study, and the Rotterdam Study. Eligible participants for these analyses were of European or African ancestry and free of clinical HF at baseline. Each study independently conducted genome-wide scans and imputed data to the approximately 2.5 million single-nucleotide polymorphisms in HapMap. Within each study, Cox proportional hazards regression models provided age- and sex-adjusted estimates of the association between each variant and time to incident HF. Fixed-effect meta-analyses combined results for each single-nucleotide polymorphism from the 4 cohorts to produce an overall association estimate and P value. A genome-wide significance P value threshold was set a priori at 5.0x10(-7). During a mean follow-up of 11.5 years, 2526 incident HF events (12%) occurred in 20 926 European-ancestry participants. The meta-analysis identified a genome-wide significant locus at chromosomal position 15q22 (1.4x10(-8)), which was 58.8 kb from USP3. Among 2895 African-ancestry participants, 466 incident HF events (16%) occurred during a mean follow-up of 13.7 years. One genome-wide significant locus was identified at 12q14 (6.7x10(-8)), which was 6.3 kb from LRIG3. We identified 2 loci that were associated with incident HF and exceeded genome-wide significance. The findings merit replication in other community-based settings of incident HF.

Detection of the mtDNA 14484 mutation on an African-specific haplotype: Implications about its role in causing Leber hereditary optic neuropathy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torroni, A.; Petrozzi, M.; Terracina, M.

1996-07-01

Leber hereditary optic neuropathy (LHON) is a maternally transmitted disease whose primary clinical manifestation is acute or subacute bilateral loss of central vision leading to central scotoma and blindness. To date, LHON has been associated with 18 mtDNA missense mutations, even though, for many of these mutations, it remains unclear whether they cause the disease, contribute to the pathology, or are nonpathogenic mtDNA polymorphisms. On the basis of numerous criteria, which include the specificity for LHON, the frequency in the general population, and the penetrance within affected pedigrees, the detection of associated defects in the respiratory chain, mutations at threemore » nucleotide positions (nps), 11778 (G{r_arrow}A), 3460 (G{r_arrow}A), and 14484 (T{r_arrow}C) have been classified as high-risk and primary LHON mutations. Overall, these three mutations encompass {ge}90% of the LHON cases. 29 refs., 1 fig.« less

Lipoprotein receptor-related protein 1 variants and dietary fatty acids: meta-analysis of European origin and African American studies

PubMed Central

Smith, CE; Ngwa, J; Tanaka, T; Qi, Q; Wojczynski, MK; Lemaitre, RN; Anderson, JS; Manichaikul, A; Mikkilä, V; van Rooij, FJA; Ye, Z; Bandinelli, S; Frazier-Wood, AC; Houston, DK; Hu, F; Langenberg, C; McKeown, NM; Mozaffarian, D; North, KE; Viikari, J; Zillikens, MC; Djoussé, L; Hofman, A; Kähönen, M; Kabagambe, EK; Loos, RJF; Saylor, GB; Forouhi, NG; Liu, Y; Mukamal, KJ; Chen, Y-DI; Tsai, MY; Uitterlinden, AG; Raitakari, O; van Duijn, CM; Arnett, DK; Borecki, IB; Cupples, LA; Ferrucci, L; Kritchevsky, SB; Lehtimäki, T; Qi, Lu; Rotter, JI; Siscovick, DS; Wareham, NJ; Witteman, JCM; Ordovás, JM; Nettleton, JA

2013-01-01

OBJECTIVE Low-density lipoprotein-related receptor protein 1 (LRP1) is a multi-functional endocytic receptor and signaling molecule that is expressed in adipose and the hypothalamus. Evidence for a role of LRP1 in adiposity is accumulating from animal and in vitro models, but data from human studies are limited. The study objectives were to evaluate (i) relationships between LRP1 genotype and anthropometric traits, and (ii) whether these relationships were modified by dietary fatty acids. DESIGN AND METHODS We conducted race/ethnic-specific meta-analyses using data from 14 studies of US and European whites and 4 of African Americans to evaluate associations of dietary fatty acids and LRP1 genotypes with body mass index (BMI), waist circumference and hip circumference, as well as interactions between dietary fatty acids and LRP1 genotypes. Seven single-nucleotide polymorphisms (SNPs) of LRP1 were evaluated in whites (N up to 42 000) and twelve SNPs in African Americans (N up to 5800). RESULTS After adjustment for age, sex and population substructure if relevant, for each one unit greater intake of percentage of energy from saturated fat (SFA), BMI was 0.104 kg m−2 greater, waist was 0.305 cm larger and hip was 0.168 cm larger (all P<0.0001). Other fatty acids were not associated with outcomes. The association of SFA with outcomes varied by genotype at rs2306692 (genotyped in four studies of whites), where the magnitude of the association of SFA intake with each outcome was greater per additional copy of the T allele: 0.107 kg m−2 greater for BMI (interaction P=0.0001), 0.267 cm for waist (interaction P=0.001) and 0.21 cm for hip (interaction P=0.001). No other significant interactions were observed. CONCLUSION Dietary SFA and LRP1 genotype may interactively influence anthropometric traits. Further exploration of this, and other diet x genotype interactions, may improve understanding of interindividual variability in the relationships of dietary factors with anthropometric traits. PMID:23357958

Duffy-Null–Associated Low Neutrophil Counts Influence HIV-1 Susceptibility in High-Risk South African Black Women

PubMed Central

Ramsuran, Veron; Kulkarni, Hemant; He, Weijing; Mlisana, Koleka; Wright, Edwina J.; Werner, Lise; Castiblanco, John; Dhanda, Rahul; Le, Tuan; Dolan, Matthew J.; Guan, Weihua; Weiss, Robin A.; Clark, Robert A.; Abdool Karim, Salim S.; Ndung'u, Thumbi

2011-01-01

Background. The Duffy-null trait and ethnic netropenia are both highly prevalent in Africa. The influence of pre-seroconversion levels of peripheral blood cell counts (PBCs) on the risk of acquiring human immunodeficiency virus (HIV)–1 infection among Africans is unknown. Methods. The triangular relationship among pre-seroconversion PBC counts, host genotypes, and risk of HIV acquisition was determined in a prospective cohort of black South African high-risk female sex workers. Twenty-seven women had seroconversion during follow-up, and 115 remained HIV negative for 2 years, despite engaging in high-risk activity. Results. Pre-seroconversion neutrophil counts in women who subsequently had seroconversion were significantly lower, whereas platelet counts were higher, compared with those who remained HIV negative. Comprising 27% of the cohort, subjects with pre-seroconversion neutrophil counts of <2500 cells/mm3 had a ∼3-fold greater risk of acquiring HIV infection. In a genome-wide association analyses, an African-specific polymorphism (rs2814778) in the promoter of Duffy Antigen Receptor for Chemokines (DARC −46T > C) was significantly associated with neutrophil counts (P = 7.9 × 10−11). DARC −46C/C results in loss of DARC expression on erthyrocytes (Duffy-null) and resistance to Plasmodium vivax malaria, and in our cohort, only subjects with this genotype had pre-seroconversion neutrophil counts of <2500 cells/mm3. The risk of acquiring HIV infection was ∼3-fold greater in those with the trait of Duffy-null–associated low neutrophil counts, compared with all other study participants. Conclusions. Pre-seroconversion neutrophil and platelet counts influence risk of HIV infection. The trait of Duffy-null–associated low neutrophil counts influences HIV susceptibility. Because of the high prevalence of this trait among persons of African ancestry, it may contribute to the dynamics of the HIV epidemic in Africa. PMID:21507922

Effect of functionally significant deiodinase single nucleotide polymorphisms on drinking behavior in alcohol dependence: an exploratory investigation

PubMed Central

Lee, MR; Schwandt, ML; Bollinger, JW; Dias, AA; Oot, EN; Goldman, D; Hodgkinson, CA; Leggio, L

2016-01-01

Background Abnormalities of the hypothalamic-pituitary-thyroid (HPT) axis have been reported in alcoholism, however, there is no definitive agreement on the specific thyroid abnormalities and their underlying mechanisms in alcohol dependence (AD). The biological activity of thyroid hormones or the availability of T3 is regulated by the three deiodinase enzymes D1, D2 and D3. In the context of alcohol use, functionally significant single nucleotide polymorphisms (SNP’s) of these deiodinase genes may play a role in HPT dysfunction. Methods The present study explored the effect of three functionally significant SNP’s (D1: rs2235544, D2: rs225014 and rs12885300) of deiodinase genes on drinking behavior and thyroid stimulating hormone (TSH) levels in alcohol dependent (N=521) and control subjects (N=228). Results Rs225014 was associated with significant differences in the amount of naturalistic alcohol drinking assessed by the Timeline Follow-Back (TLFB). Alcohol-dependent subjects had significantly higher thyroid stimulating hormone levels compared to controls; however, there was no effect of genotype on TSH levels for either group. Conclusions These findings extend previous studies on thyroid dysfunction in alcoholism and provide novel, albeit preliminary, information by linking functionally significant genetic polymorphisms of the deiodinase enzymes with alcohol drinking behavior. PMID:26207529

A novel polymorphic cytochrome P450 formed by splicing of CYP3A7 and the pseudogene CYP3AP1.

PubMed

Rodriguez-Antona, Cristina; Axelson, Magnus; Otter, Charlotta; Rane, Anders; Ingelman-Sundberg, Magnus

2005-08-05

The cytochrome P450 3A7 (CYP3A7) is the most abundant CYP in human liver during fetal development and first months of postnatal age, playing an important role in the metabolism of endogenous hormones, drugs, differentiation factors, and potentially toxic and teratogenic substrates. Here we describe and characterize a novel enzyme, CYP3A7.1L, encompassing the CYP3A7.1 protein with the last four carboxyl-terminal amino acids replaced by a unique sequence of 36 amino acids, generated by splicing of CYP3A7 with CYP3AP1 RNA. The corresponding CYP3A7-3AP1 mRNA had a significant expression in liver, kidney, and gastrointestinal tract, and its presence was found to be tissue-specific and dependent on the developmental stage. Heterologous expression in yeast revealed that CYP3A7.1L was a functional enzyme with a specific activity similar to that of CYP3A7.1 and, in some conditions, a different hydroxylation specificity than CYP3A7.1 using dehydroepiandrosterone as a substrate. CYP3A7.1L was found to be polymorphic due to a mutation at position -6 of the first splicing site of CYP3AP1 (CYP3A7_39256T-->A), which abrogates the pseudogene splicing. This polymorphism had pronounced interethnic differences and was in linkage disequilibrium with other functional polymorphisms described in the CYP3A locus: CYP3A7*2 and CYP3A5*1. Therefore, the resulting CYP3A haplotypes express different sets of enzymes within the population. In conclusion, a novel mechanism, consisting of the splicing of the pseudogene CYP3AP1 to CYP3A7, causes the formation of the novel CYP3A7.1L having a different tissue distribution and functional properties than the parent CYP3A7 enzyme, with possible developmental, physiological, and toxicological consequences.

The COMT Val/Met polymorphism is associated with reading-related skills and consistent patterns of functional neural activation.

PubMed

Landi, Nicole; Frost, Stephen J; Mencl, W Einar; Preston, Jonathan L; Jacobsen, Leslie K; Lee, Maria; Yrigollen, Carolyn; Pugh, Kenneth R; Grigorenko, Elena L

2013-01-01

In both children and adults there is large variability in reading skill, with approximately 5-10% of individuals characterized as having reading disability; these individuals struggle to learn to read despite adequate intelligence and opportunity. Although it is well established that a substantial portion of this variability is attributed to the genetic differences between individuals, specifics of the connections between reading and the genome are not understood. This article presents data that suggest that variation in the COMT gene, which has previously been associated with variation in higher-order cognition, is associated with reading and reading-related skills, at the level of both brain and behavior. In particular, we found that the COMT Val/Met polymorphism at rs4680, which results in the substitution of the ancestral Valine (Val) by Methionine (Met), was associated with better performance on a number of critical reading measures and with patterns of functional neural activation that have been linked to better readers. We argue that this polymorphism, known for its broad effects on cognition, may modulate (likely through frontal lobe function) reading skill. © 2012 Blackwell Publishing Ltd.

The COMT Val/Met polymorphism is associated with reading related skills and consistent patterns of functional neural activation

PubMed Central

Landi, Nicole; Frost, Stephen J.; Mencl, W. Einar; Preston, Jonathan L.; Jacobsen, Leslie K.; Lee, Maria; Yrigollen, Carolyn; Pugh, Kenneth R.; Grigorenko, Elena L.

2013-01-01

In both children and adults there is large variability in reading skill, with approximately 5–10% of individuals characterized as having reading disability; these individuals struggle to learn to read despite adequate intelligence and opportunity. Although it is well established that a substantial portion of this variability is attributed to the genetic differences between individuals, specifics of the connections between reading and the genome are not understood. This article presents data that suggest that variation in the COMT gene, which has previously been associated with variation in higher-order cognition, is associated with reading and reading-related skills, both at the level of brain and behavior. In particular, we found that the COMT Val/Met polymorphism at rs4680, which results in the substitution of the ancestral Valine (Val) by Methionine (Met), was associated with better performance on a number of critical reading measures and with patterns of functional neural activation that have been linked to better readers. We argue that this polymorphism, known for its broad effects on cognition, may modulate (likely through frontal lobe function) reading skill. PMID:23278923

Base excision repair genes and risk of lung cancer among San Francisco Bay Area Latinos and African-Americans

PubMed Central

Chang, Jeffrey S.; Wrensch, Margaret R.; Hansen, Helen M.; Sison, Jennette D.; Aldrich, Melinda C.; Quesenberry, Charles P.; Seldin, Michael F.; Kelsey, Karl T.; Wiencke, John K.

2009-01-01

Base excision repair (BER) is the primary DNA damage repair mechanism for repairing small base lesions resulting from oxidation and alkylation damage. This study examines the association between 24 single-nucleotide polymorphisms (SNPs) belonging to five BER genes (XRCC1, APEX1, PARP1, MUTYH and OGG1) and lung cancer among Latinos (113 cases and 299 controls) and African-Americans (255 cases and 280 controls). The goal was to evaluate the differences in genetic contribution to lung cancer risk by ethnic groups. Analyses of individual SNPs and haplotypes were performed using unconditional logistic regressions adjusted for age, sex and genetic ancestry. Four SNPs among Latinos and one SNP among African-Americans were significantly (P < 0.05) associated with either risk of all lung cancer or non-small cell lung cancer (NSCLC). However, only the association between XRCC1 Arg399Gln (rs25487) and NSCLC among Latinos (odds ratio associated with every copy of Gln = 1.52; 95% confidence interval: 1.01–2.28) had a false-positive report probability of <0.5. Arg399Gln is a SNP with some functional evidence and has been shown previously to be an important SNP associated with lung cancer, mostly for Asians. Since the analyses were adjusted for genetic ancestry, the observed association between Arg399Gln and NSCLC among Latinos is unlikely to be confounded by population stratification; however, this result needs to be confirmed by additional studies among the Latino population. This study suggests that there are genetic differences in the association between BER pathway and lung cancer between Latinos and African-Americans. PMID:19029194

Raising African American boys: an exploration of gender and racial socialization practices.

PubMed

Howard, Lionel C; Rose, Jason C; Barbarin, Oscar A

2013-01-01

Although parental socialization practices are critical to a child's social development, little is known of the details of how parental practices function to meet the specific challenges of supporting young boys' development as African American and men. Accordingly, this article offers a window onto how 15 parents of African American boys (ages 3-8) conceive and implement strategies for their sons' social and emotional development. Using ethnographic observations and structured interview data, this article explores the ways they promote emerging racial and gender identities and socioemotional well-being. Findings reveal that highly incongruous messages and expectations are communicated to young boys about race and gender. The study's findings have implications for young African American boys' emerging racial and gender identities. © 2013 American Orthopsychiatric Association.

Association of calcium sensing receptor polymorphisms at rs1801725 with circulating calcium in breast cancer patients.

PubMed

Wang, Li; Widatalla, Sarrah E; Whalen, Diva S; Ochieng, Josiah; Sakwe, Amos M

2017-08-02

Breast cancer (BC) patients with late-stage and/or rapidly growing tumors are prone to develop high serum calcium levels which have been shown to be associated with larger and aggressive breast tumors in post and premenopausal women respectively. Given the pivotal role of the calcium sensing receptor (CaSR) in calcium homeostasis, we evaluated whether polymorphisms of the CASR gene at rs1801725 and rs1801726 SNPs in exon 7, are associated with circulating calcium levels in African American and Caucasian control subjects and BC cases. In this retrospective case-control study, we assessed the mean circulating calcium levels, the distribution of two inactivating CaSR SNPs at rs1801725 and rs1801726 in 199 cases and 384 age-matched controls, and used multivariable regression analysis to determine whether these SNPs are associated with circulating calcium in control subjects and BC cases. We found that the mean circulating calcium levels in African American subjects were higher than those in Caucasian subjects (p < 0.001). As expected, the mean calcium levels were higher in BC cases compared to control subjects (p < 0.001), but the calcium levels in BC patients were independent of race. We also show that in BC cases and control subjects, the major alleles at rs1801725 (G/T, A986S) and at rs1801726 (C/G, Q1011E) were common among Caucasians and African Americans respectively. Compared to the wild type alleles, polymorphisms at the rs1801725 SNP were associated with higher calcium levels (p = 0.006) while those at rs1801726 were not. Using multivariable linear mixed-effects models and adjusting for age and race, we show that circulating calcium levels in BC cases were associated with tumor grade (p = 0.009), clinical stage (p = 0.003) and more importantly, with inactivating mutations of the CASR at the rs1801725 SNP (p = 0.038). These data suggest that decreased sensitivity of the CaSR to calcium due to inactivating polymorphisms at rs1801725, may predispose up to 20% of BC cases to high circulating calcium-associated larger and/or aggressive breast tumors.

Analysis for genotyping Duffy blood group in inhabitants of Sudan, the Fourth Cataract of the Nile

PubMed Central

2012-01-01

Background Genetic polymophisms of the Duffy antigen receptor for the chemokines (DARC) gene successfully protected against blood stage infection by Plasmodium vivax infection. The Fy (a-, b-) phenotype is predominant among African populations, particularly those originating from West Africa, and it is rare among non-African populations. The aim of this study was to analyse the frequency of four Duffy blood groups based on SNPs (T-33C, G125A, G298A and C5411T) in two local tribes of Sudanese Arabs, the Shagia and Manasir, which are both from the region of the Fourth Nile cataract in Sudan. Methods An analysis of polymorphisms was performed on 217 individuals (126 representatives of the Shagia tribe and 91 of the Manasir). Real-time PCR and TaqMan Genotyping Assays were used to study the prevalence of alleles and genotypes. Results The analysis of allelic and genotype frequency in the T-33C polymorphisms demonstrated a significant dominance of the C allele and CC genotype (OR = 0.53 [0.32-0.88]; p = 0.02) in both tribes. The G125A polymorphism is associated with phenotype Fy(a-, b-) and was identified in 83% of Shagia and 77% of Manasir. With regard to G298A polymorphisms, the genotype frequencies were different between the tribes (p = 0,002) and no single AA homozygote was found. Based on four SNPs examined, 20 combinations of genotypes for the Shagia and Manasir tribes were determined. The genotype CC/AA/GG/CT occurred most often in Shagia tribe (45.9%) but was rare in the Manasir tribe (6.6%) (p < 0.001 Shagia versus Manasir). The FY*AES allele was identified in both analysed tribes. The presence of individuals with the FY*A/FY*A genotype was demonstrated only in the Shagia tribe. Conclusion This is probably the first report showing genotypically Duffy-negative people who carry both FY*BES and FY*AES. The identification of the FY*AES allele in both tribes may be due to admixture of the non-African genetic background. Taken as a whole, allele and genotype frequencies between the Shagia and the Manasir were statistically different. However, the presence of individuals with the FY*A/FY*A genotype was demonstrated only in the Shagia tribe. PMID:22510366

Her2 Ile655Val polymorphism and its association with breast cancer risk: an updated meta-analysis of case-control studies.

PubMed

Krishna, B Madhu; Chaudhary, Sanjib; Panda, Aditya K; Mishra, Dipti Ranjan; Mishra, Sandip K

2018-05-09

Breast cancer (BC) is one of the most common types of cancer in women worldwide. Several factors including genetic and environmental have been linked with susceptibility to development of BC. Her2 is a transmembrane protein with tyrosine kinase activity, overexpressed in several cancers including BC. Various studies in different populations have shown association of Her2 variants with susceptibility to BC, however these results were inconsistent, inconclusive and controversial. To obtain a common conclusive finding, we performed meta-analysis of 35 case-control studies reported earlier including 19, 220 cases and 22, 306 controls. We observed significant association of Her2 Ile 655 Val polymorphism with susceptibility to development of breast cancer (Overall allele Val vs Ile: OR = 1.130, 95% CI = 1.051-1.216, p = 0.001; Ile-Val vs Ile-Ile: OR = 1.100, 95% CI = 1.016-1.192, p = 0.019; Val-Val+Ile-Val vs Ile-Ile: OR = 1.127, 95% CI = 1.038-1.223, p = 0.004). Subgroup analysis indicated a significant association with susceptibility to breast cancer in African and Asian populations. However, such association was not observed in other ethnic groups. Our findings suggested that Her2 Ile 655 Val polymorphism is associated with breast cancer risk in overall, Asian and African populations, and can be used as diagnostic marker for BC.

A Functional Tph2 C1473G Polymorphism Causes an Anxiety Phenotype via Compensatory Changes in the Serotonergic System

PubMed Central

Berger, Stefan M; Weber, Tillmann; Perreau-Lenz, Stephanie; Vogt, Miriam A; Gartside, Sarah E; Maser-Gluth, Christiane; Lanfumey, Laurence; Gass, Peter; Spanagel, Rainer; Bartsch, Dusan

2012-01-01

The association of single-nucleotide polymorphisms (SNPs) in the human tryptophan hydroxylase 2 (TPH2) gene with anxiety traits and depression has been inconclusive. Observed inconsistencies might result from the fact that TPH2 polymorphisms have been studied in a genetically heterogeneous human population. A defined genetic background, control over environmental factors, and the ability to analyze the molecular and neurochemical consequences of introduced genetic alterations constitute major advantages of investigating SNPs in inbred laboratory mouse strains. To investigate the behavioral and neurochemical consequences of a functional C1473G SNP in the mouse Tph2 gene, we generated congenic C57BL/6N mice homozygous for the Tph2 1473G allele. The Arg447 substitution in the TPH2 enzyme resulted in a significant reduction of the brain serotonin (5-HT) in vivo synthesis rate. Despite decreased 5-HT synthesis, we could detect neither a reduction of brain region-specific 5-HT concentrations nor changes in baseline and stress-induced 5-HT release using a microdialysis approach. However, using a [35S]GTP-γ-S binding assay and 5-HT1A receptor autoradiography, a functional desensitization of 5-HT1A autoreceptors could be identified. Furthermore, behavioral analysis revealed a distinct anxiety phenotype in homozygous Tph2 1473G mice, which could be reversed with chronic escitalopram treatment. Alterations in depressive-like behavior could not be detected under baseline conditions or after chronic mild stress. These findings provide evidence for an involvement of functional Tph2 polymorphisms in anxiety-related behaviors, which are likely not caused directly by alterations in 5-HT content or release but are rather due to compensatory changes during development involving functional desensitization of 5-HT1A autoreceptors. PMID:22491354

Functional genetic variants in the vesicular monoamine transporter 1 modulate emotion processing.

PubMed

Lohoff, F W; Hodge, R; Narasimhan, S; Nall, A; Ferraro, T N; Mickey, B J; Heitzeg, M M; Langenecker, S A; Zubieta, J-K; Bogdan, R; Nikolova, Y S; Drabant, E; Hariri, A R; Bevilacqua, L; Goldman, D; Doyle, G A

2014-01-01

Emotional behavior is in part heritable and often disrupted in psychopathology. Identification of specific genetic variants that drive this heritability may provide important new insight into molecular and neurobiological mechanisms involved in emotionality. Our results demonstrate that the presynaptic vesicular monoamine transporter 1 (VMAT1) Thr136Ile (rs1390938) polymorphism is functional in vitro, with the Ile allele leading to increased monoamine transport into presynaptic vesicles. Moreover, we show that the Thr136Ile variant predicts differential responses in emotional brain circuits consistent with its effects in vitro. Lastly, deep sequencing of bipolar disorder (BPD) patients and controls identified several rare novel VMAT1 variants. The variant Phe84Ser was only present in individuals with BPD and leads to marked increase monoamine transport in vitro. Taken together, our data show that VMAT1 polymorphisms influence monoamine signaling, the functional response of emotional brain circuits and risk for psychopathology.

TPH2 G/T polymorphism is associated with hyperphagia, IQ, and internalizing problems in Prader-Willi syndrome

PubMed Central

Dykens, Elisabeth M.; Roof, Elizabeth; Bittel, Douglas; Butler, Merlin G.

2010-01-01

Background Prader-Willi syndrome (PWS) is a genetic, neurodevelopmental disorder characterized by intellectual disabilities, growth hormone dysregulation, hyperphagia, increased risks of morbid obesity, compulsive behaviors, and irritability. As aberrant serotonergic functioning is strongly implicated in PWS, we examined associations between the PWS phenotype and polymorphisms in tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme in the biosynthesis of serotonin in the brain. Methods 92 individuals with PWS aged 4 to 50 years (M = 21.97) were genotyped for the TPH2 G703-T polymorphism. IQ testing was conducted in offspring, and parents completed questionnaires that tapped their child’s compulsivity, hyperphagia, and other behavior problems. Results As expected, the frequency of G/T or T/T polymorphisms in participants with PWS (39%) was similar to rates found in the general population (38%). Compared to those with a homozygous (G/G) genotype, individuals with a T allele had significantly higher hyperphagic behavior, drive, and severity scores, and they also had a younger age of onset of hyperphagia. Those with a T allele also had higher IQ scores than their counterparts. Females with a T allele had significantly higher internalizing symptoms, primarily anxiety and depression, than all others. Conclusions TPH2 G/T polymorphisms, and presumed loss of enzyme function, were associated with specific aspects of the PWS phenotype. Aberrant serotonergic functioning is strongly implicated in hyperphagia in PWS, and females with TPH2 T alleles may be at higher risk for affective or mood disorders. Findings hold promise for examining other serotonin-altering genes in PWS, and for future serotonin-altering treatment trials. PMID:21418060

TPH2 G/T polymorphism is associated with hyperphagia, IQ, and internalizing problems in Prader-Willi syndrome.

PubMed

Dykens, Elisabeth M; Roof, Elizabeth; Bittel, Douglas; Butler, Merlin G

2011-05-01

Prader-Willi syndrome (PWS) is a genetic, neurodevelopmental disorder characterized by intellectual disabilities, growth hormone dysregulation, hyperphagia, increased risks of morbid obesity, compulsive behaviors, and irritability. As aberrant serotonergic functioning is strongly implicated in PWS, we examined associations between the PWS phenotype and polymorphisms in tryptophan hydroxylase 2 (TPH2), the rate-limiting enzyme in the biosynthesis of serotonin in the brain. Ninety-two individuals with PWS aged 4 to 50 years (M = 21.97) were genotyped for the TPH2 G703-T polymorphism. IQ testing was conducted in offspring, and parents completed questionnaires that tapped their child's compulsivity, hyperphagia, and other behavior problems. As expected, the frequency of G/T or T/T polymorphisms in participants with PWS (39%) was similar to rates found in the general population (38%). Compared to those with a homozygous (G/G) genotype, individuals with a T allele had significantly higher hyperphagic behavior, drive, and severity scores, and they also had a younger age of onset of hyperphagia. Those with a T allele also had higher IQ scores than their counterparts. Females with a T allele had significantly higher internalizing symptoms, primarily anxiety and depression, than all others. TPH2 G/T polymorphisms, and presumed loss of enzyme function, were associated with specific aspects of the PWS phenotype. Aberrant serotonergic functioning is strongly implicated in hyperphagia in PWS, and females with TPH2 T alleles may be at higher risk for affective or mood disorders. Findings hold promise for examining other serotonin-altering genes in PWS, and for future serotonin-altering treatment trials. © 2011 The Authors. Journal of Child Psychology and Psychiatry © 2011 Association for Child and Adolescent Mental Health.

Validation and Interrogation of Differentially Expressed and Alternatively Spliced Genes in African-American Prostate Cancer

DTIC Science & Technology

2015-10-01

Epigenetic Regulation of Tyrosine Receptor Kinases and Childhood Respiratory Disease (Murphy – Duke site PI) Time Commitment: 5% 0.6 calendar...children to the risk of childhood asthma and lower lung function when exposed to prenatal tobacco smoke. Specific Aims: Specific aims are: (1) to...epigenetic and/or genetic variation in the TAM genes are independently or jointly associated with childhood asthma and 24 with attained lung function at

Alcohol and aldehyde dehydrogenase polymorphisms in Chinese and Indian populations.

PubMed

Tan, Ene-Choo; Lim, Leslie; Leong, Jern-Yi; Lim, Jing-Yan; Lee, Arthur; Yang, Jun; Tan, Chay-Hoon; Winslow, Munidasa

2010-01-01

The association between two functional polymorphisms in alcohol dehydrogenase (ADH2/ADH1B) and aldehyde dehydrogenase (ALDH2) genes and alcohol dependence was examined in 182 Chinese and Indian patients undergoing treatment for alcohol dependence and 184 screened control subjects from Singapore. All subjects were screened by the Alcohol Use Disorders Identification Test (AUDIT). Patients were also administered the Severity of Alcohol Dependence Questionnaire (SADQ). Polymorphisms were genotyped by allele-specific polymerase chain reaction and selected genotypes confirmed by DNA sequencing or restriction fragment length polymorphism. Our results showed that frequencies of ADH1B*2 and ALDH2*2 were higher in controls compared to alcohol-dependent subjects for both Chinese and Indians. Frequencies of these two alleles were also higher in the 104 Chinese controls compared to the 80 Indian controls. None of the eight Chinese who were homozygous for both protective alleles was alcohol dependent. The higher frequencies of the protective alleles could explain the lower rate of alcohol dependence in Chinese.

A Common Polymorphism in SCN2A Predicts General Cognitive Ability Through Effects on Prefrontal Cortex Physiology

PubMed Central

Scult, Matthew A.; Trampush, Joey W.; Zheng, Fengyu; Conley, Emily Drabant; Lencz, Todd; Malhotra, Anil K.; Dickinson, Dwight; Weinberger, Daniel R.; Hariri, Ahmad R.

2015-01-01

Here we provide novel convergent evidence across three independent cohorts of healthy adults (n=531) demonstrating that a common polymorphism in the gene encoding the α2 subunit of neuronal voltage-gated type II sodium channels (SCN2A) predicts human general cognitive ability or “g.” Using meta-analysis, we demonstrate that the minor T allele of a common polymorphism (rs10174400) in SCN2A is associated with significantly higher “g” independent of gender and age. We further demonstrate using resting-state fMRI data from our discovery cohort (n=236) that this genetic advantage may be mediated by increased capacity for information processing between the dorsolateral prefrontal cortex and dorsal anterior cingulate cortex, which support higher cognitive functions. Collectively, these findings fill a gap in our understanding of the genetics of general cognitive ability and highlight a specific neural mechanism through which a common polymorphism shapes inter-individual variation in “g.” PMID:25961639

The D allele of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism is associated with worse functional outcome of ischaemic stroke.

PubMed

Malueka, Rusdy Ghazali; Dwianingsih, Ery Kus; Sutarni, Sri; Bawono, Rheza Gandi; Bayuangga, Halwan Fuad; Gofir, Abdul; Setyopranoto, Ismail

2017-12-29

Insertion/deletion polymorphism in ACE gene (ACE I/D) is known to be associated with the occurrence of ischaemic stroke through its effect on pathogenesis of atherosclerosis and hypertension. This study was aimed to examine the association between this polymorphism with functional outcome of ischaemic stroke. This was a cross-sectional study. The subjects were patients with ischaemic stroke in a reference hospital in Yogyakarta, Indonesia. Data on demographic characteristics, stroke risk factors, comorbidities and stroke severity were assessed on admission. The functional outcome, Barthel index (BI), was assessed when the patients were discharged from the hospital. ACE I/D genotypes of the patients were identified by polymerase chain reaction (PCR). In total, 61 patients were included. Of these, 38 patients (62.3%) had II polymorphism, 22 patients (36.1%) had ID polymorphism and 1 patient (1.6%) had DD polymorphism in the ACE gene. There were significant differences in the functional outcomes between patients without D allele (II polymorphisms) and patients with D allele (ID and DD polymorphism) (mean BI on discharge: 75 ± 23.57 and 60.65 ± 27.15, respectively; p = 0.034). Multiple linear regression model showed that the availability of D allele is an independent variable negatively associated with functional outcome as assessed by BI (β = -0.232, p = 0.024). This study showed that the D allele in ACE I/D polymorphism is associated with worse functional outcomes. This highlights the possibility of further research to improve functional outcomes of ischaemic stroke by inhibiting the ACE system.

A common FADS2 promoter polymorphism increases promoter activity and facilitates binding of transcription factor ELK1

PubMed Central

Lattka, E.; Eggers, S.; Moeller, G.; Heim, K.; Weber, M.; Mehta, D.; Prokisch, H.; Illig, T.; Adamski, J.

2010-01-01

Fatty acid desaturases (FADS) play an important role in the formation of omega-6 and omega-3 highly unsaturated fatty acids (HUFAs). The composition of HUFAs in the human metabolome is important for membrane fluidity and for the modulation of essential physiological functions such as inflammation processes and brain development. Several recent studies reported significant associations of single nucleotide polymorphisms (SNPs) in the human FADS gene cluster with HUFA levels and composition. The presence of the minor allele correlated with a decrease of desaturase reaction products and an accumulation of substrates. We performed functional studies with two of the associated polymorphisms (rs3834458 and rs968567) and showed an influence of polymorphism rs968567 on FADS2 promoter activity by luciferase reporter gene assays. Electrophoretic mobility shift assays proved allele-dependent DNA-binding ability of at least two protein complexes to the region containing SNP rs968567. One of the proteins binding to this region in an allele-specific manner was shown to be the transcription factor ELK1 (a member of ETS domain transcription factor family). These results indicate that rs968567 influences FADS2 transcription and offer first insights into the modulation of complex regulation mechanisms of FADS2 gene transcription by SNPs. PMID:19546342

A common FADS2 promoter polymorphism increases promoter activity and facilitates binding of transcription factor ELK1.

PubMed

Lattka, E; Eggers, S; Moeller, G; Heim, K; Weber, M; Mehta, D; Prokisch, H; Illig, T; Adamski, J

2010-01-01

Fatty acid desaturases (FADS) play an important role in the formation of omega-6 and omega-3 highly unsaturated fatty acids (HUFAs). The composition of HUFAs in the human metabolome is important for membrane fluidity and for the modulation of essential physiological functions such as inflammation processes and brain development. Several recent studies reported significant associations of single nucleotide polymorphisms (SNPs) in the human FADS gene cluster with HUFA levels and composition. The presence of the minor allele correlated with a decrease of desaturase reaction products and an accumulation of substrates. We performed functional studies with two of the associated polymorphisms (rs3834458 and rs968567) and showed an influence of polymorphism rs968567 on FADS2 promoter activity by luciferase reporter gene assays. Electrophoretic mobility shift assays proved allele-dependent DNA-binding ability of at least two protein complexes to the region containing SNP rs968567. One of the proteins binding to this region in an allele-specific manner was shown to be the transcription factor ELK1 (a member of ETS domain transcription factor family). These results indicate that rs968567 influences FADS2 transcription and offer first insights into the modulation of complex regulation mechanisms of FADS2 gene transcription by SNPs.

The Impact of BDNF Polymorphisms on Suicidality in Treatment-Resistant Major Depressive Disorder: A European Multicenter Study.

PubMed

Schosser, Alexandra; Carlberg, Laura; Calati, Raffaella; Serretti, Alessandro; Massat, Isabel; Spindelegger, Christoph; Linotte, Sylvie; Mendlewicz, Julien; Souery, Daniel; Zohar, Joseph; Montgomery, Stuart; Kasper, Siegfried

2017-10-01

Numerous studies have reported associations between the brain-derived neurotrophic factor (BDNF) gene and psychiatric disorders, including suicidal behavior, although with conflicting results. A total of 250 major depressive disorder patients were collected in the context of a European multicenter resistant depression study and treated with antidepressants at adequate doses for at least 4 weeks. Suicidality was assessed using the Mini International Neuropsychiatric Interview and Hamilton Rating Scale for Depression, and treatment response using the HAM-D. Genotyping was performed for the functional Val66Met polymorphism (rs6265) and 7 additional tagging single nucleotide polymorphisms within the BDNF gene. Neither BDNF single markers nor haplotypes were found to be associated with suicide risk and lifetime history of suicide attempts. Gender-specific analyses revealed nonsignificant single marker (rs908867) and haplotypic association with suicide risk in males after multiple testing correction. Analyzing treatment response phenotypes, the functional Val66Met polymorphism as well as rs10501087 showed significant genotypic and haplotypic association with suicide risk in remitters (n=34, 13.6%). Considering the sample size, the present findings need to be replicated in larger samples to confirm or refute a role of BDNF in the investigated suicidal behavior phenotypes. © The Author 2017. Published by Oxford University Press on behalf of CINP.

African Music in the Americas

ERIC Educational Resources Information Center

Goines, Leonard

1977-01-01

Discusses African music, how it survived slavery, why it manifests itself in specific forms, why some of these forms are almost purely African today while others are very European, the specific characteristics of African music that permeate all African-American music, and why African derived religions are flourishing in the black communities of…

Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in Commensal Gut Bacteria

PubMed Central

Ramiro, Ricardo S.; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, Isabel

2017-01-01

Abstract The evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) spread to >90% frequency in all colonized mice. Here, we show that this loss-of-function is repeatedly reversed when a gat-negative clone colonizes new mice. The regain of function occurs via compensatory mutation and reversion, the latter leaving no trace of past adaptation. We further show that loss-of-function adaptive mutants reevolve, after colonization with an evolved gat-positive clone. Thus, even under strong bottlenecks a regime of strong-mutation-strong-selection dominates adaptation. Coupling experiments and modeling, we establish that reverse evolution recurrently generates two coexisting phenotypes within the microbiota that can or not consume galactitol (gat-positive and gat-negative, respectively). Although the abundance of the dominant strain, the gat-negative, depends on the microbiota composition, gat-positive abundance is independent of the microbiota composition and can be precisely manipulated by supplementing the diet with galactitol. These results show that a specific diet is able to change the abundance of specific strains. Importantly, we find polymorphism for these phenotypes in indigenous Enterobacteria of mice and man. Our results demonstrate that natural selection can greatly overwhelm genetic drift at structuring the strain diversity of gut commensals and that competition for limiting resources may be a key mechanism for maintaining polymorphism in the gut. PMID:28961745

FTO Genetic Variation and Association With Obesity in West Africans and African Americans

PubMed Central

Adeyemo, Adebowale; Chen, Guanjie; Zhou, Jie; Shriner, Daniel; Doumatey, Ayo; Huang, Hanxia; Rotimi, Charles

2010-01-01

OBJECTIVE The FTO gene is one of the most consistently replicated loci for obesity. However, data from populations of African ancestry are limited. We evaluated genetic variation in the FTO gene and investigated associations with obesity in West Africans and African Americans. RESEARCH DESIGN AND METHODS The study samples comprised 968 African Americans (59% female, mean age 49 years, mean BMI 30.8 kg/m2) and 517 West Africans (58% female, mean age 54 years, mean BMI 25.5 kg/m2). FTO genetic variation was evaluated by genotyping 262 tag single nucleotide polymorphisms (SNPs) across the entire gene. Association of each SNP with BMI, waist circumference, and percent fat mass was investigated under an additive model. RESULTS As expected, both African-ancestry samples showed weaker linkage disequilibrium (LD) patterns compared with other continental (e.g., European) populations. Several intron 8 SNPs, in addition to intron 1 SNPs, showed significant associations in both study samples. The combined effect size for BMI for the top SNPs from meta-analysis was 0.77 kg/m2 (P = 0.009, rs9932411) and 0.70 kg/m2 (P = 0.006, rs7191513). Two previously reported associations with intron 1 SNPs (rs1121980 and rs7204609, r2 = 0.001) were replicated among the West Africans. CONCLUSIONS The FTO gene shows significant differences in allele frequency and LD patterns in populations of African ancestry compared with other continental populations. Despite these differences, we observed evidence of associations with obesity in African Americans and West Africans, as well as evidence of heterogeneity in association. More studies of FTO in multiple ethnic groups are needed. PMID:20299471

Efficient selection of tagging single-nucleotide polymorphisms in multiple populations.

PubMed

Howie, Bryan N; Carlson, Christopher S; Rieder, Mark J; Nickerson, Deborah A

2006-08-01

Common genetic polymorphism may explain a portion of the heritable risk for common diseases, so considerable effort has been devoted to finding and typing common single-nucleotide polymorphisms (SNPs) in the human genome. Many SNPs show correlated genotypes, or linkage disequilibrium (LD), suggesting that only a subset of all SNPs (known as tagging SNPs, or tagSNPs) need to be genotyped for disease association studies. Based on the genetic differences that exist among human populations, most tagSNP sets are defined in a single population and applied only in populations that are closely related. To improve the efficiency of multi-population analyses, we have developed an algorithm called MultiPop-TagSelect that finds a near-minimal union of population-specific tagSNP sets across an arbitrary number of populations. We present this approach as an extension of LD-select, a tagSNP selection method that uses a greedy algorithm to group SNPs into bins based on their pairwise association patterns, although the MultiPop-TagSelect algorithm could be used with any SNP tagging approach that allows choices between nearly equivalent SNPs. We evaluate the algorithm by considering tagSNP selection in candidate-gene resequencing data and lower density whole-chromosome data. Our analysis reveals that an exhaustive search is often intractable, while the developed algorithm can quickly and reliably find near-optimal solutions even for difficult tagSNP selection problems. Using populations of African, Asian, and European ancestry, we also show that an optimal multi-population set of tagSNPs can be substantially smaller (up to 44%) than a typical set obtained through independent or sequential selection.

Male Lineages in Brazil: Intercontinental Admixture and Stratification of the European Background.

PubMed

Resque, Rafael; Gusmão, Leonor; Geppert, Maria; Roewer, Lutz; Palha, Teresinha; Alvarez, Luis; Ribeiro-dos-Santos, Ândrea; Santos, Sidney

2016-01-01

The non-recombining nature of the Y chromosome and the well-established phylogeny of Y-specific Single Nucleotide Polymorphisms (Y-SNPs) make them useful for defining haplogroups with high geographical specificity; therefore, they are more apt than the Y-STRs to detect population stratification in admixed populations from diverse continental origins. Different Y-SNP typing strategies have been described to address issues of population history and movements within geographic territories of interest. In this study, we investigated a set of 41 Y-SNPs in 1217 unrelated males from the five Brazilian geopolitical regions, aiming to disclose the genetic structure of male lineages in the country. A population comparison based on pairwise FST genetic distances did not reveal statistically significant differences in haplogroup frequency distributions among populations from the different regions. The genetic differences observed among regions were, however, consistent with the colonization history of the country. The sample from the Northern region presented the highest Native American ancestry (8.4%), whereas the more pronounced African contribution could be observed in the Northeastern population (15.1%). The Central-Western and Southern samples showed the higher European contributions (95.7% and 93.6%, respectively). The Southeastern region presented significant European (86.1%) and African (12.0%) contributions. The subtyping of the most frequent European lineage in Brazil (R1b1a-M269) allowed differences in the genetic European background of the five Brazilian regions to be investigated for the first time.

Male Lineages in Brazil: Intercontinental Admixture and Stratification of the European Background

PubMed Central

Geppert, Maria; Roewer, Lutz; Palha, Teresinha; Alvarez, Luis; Ribeiro-dos-Santos, Ândrea; Santos, Sidney

2016-01-01

The non-recombining nature of the Y chromosome and the well-established phylogeny of Y-specific Single Nucleotide Polymorphisms (Y-SNPs) make them useful for defining haplogroups with high geographical specificity; therefore, they are more apt than the Y-STRs to detect population stratification in admixed populations from diverse continental origins. Different Y-SNP typing strategies have been described to address issues of population history and movements within geographic territories of interest. In this study, we investigated a set of 41 Y-SNPs in 1217 unrelated males from the five Brazilian geopolitical regions, aiming to disclose the genetic structure of male lineages in the country. A population comparison based on pairwise FST genetic distances did not reveal statistically significant differences in haplogroup frequency distributions among populations from the different regions. The genetic differences observed among regions were, however, consistent with the colonization history of the country. The sample from the Northern region presented the highest Native American ancestry (8.4%), whereas the more pronounced African contribution could be observed in the Northeastern population (15.1%). The Central-Western and Southern samples showed the higher European contributions (95.7% and 93.6%, respectively). The Southeastern region presented significant European (86.1%) and African (12.0%) contributions. The subtyping of the most frequent European lineage in Brazil (R1b1a-M269) allowed differences in the genetic European background of the five Brazilian regions to be investigated for the first time. PMID:27046235

Association Studies of Specific Cholesterol Related Genes (APOE, LPL, and CETP) with Lipid Profile and Memory Function: A Correlative Study Among Rural and Tribal Population of Dharmapuri District, India.

PubMed

Periyasamy, Sabapathy; Sathya, Mohan; Karthick, Chennakesavan; Kandasamy, Mahesh; Shanmugaapriya, Sellathamby; Tamilselvan, Jeyavelu; Jayachandran, Kesavan Swaminathan; Anusuyadevi, Muthuswamy

2017-01-01

 Epidemiological studies state that dementia has multiple etiologies including genetic mutation, genetic variation, and environmental factors. Accumulating evidence suggests that dysregulation of cholesterol homeostasis is the major etiological factor in initiating neurodegeneration. Apolipoprotein E (APOE) polymorphic alleles and associated polymorphism of lipoprotein lipase (LPL) and cholesteryl ester transfer protein (CETP) that are important components in regulating cholesterol metabolism are implicated in neurodegenerative diseases. Therefore, the current study focused on identifying the association between several common polymorphism (viz., APOE, CETP, and LPL) to that of change in serum lipid levels and memory symptoms. Volunteer subjects aged 50 and above from rural and tribal areas of the Dharmapuri district, Tamilnadu, India were chosen for the current study and polymorphism was analyzed using PCR-RFLP. Fasting lipid profile and memory function using simplified version of Global Clinical Dementia rating were assessed. Significant difference in the major lipid profile parameters were observed (TC, TGL, LDL, VLDL) among rural and tribal populations that were associated with significant genotypic variation of APOE, CETP, and LPL. Regression analysis revealed significant risk for memory loss that are dependent on age and genetic variants like CETP. These data predict positive correlation between cholesterol-associated genes and their relationship to altered lipid profile and memory symptoms, which possibly link gene-polymorphism and susceptibility ratio for aging and dementia.

Specific Cell Targeting Therapy Bypasses Drug Resistance Mechanisms in African Trypanosomiasis

PubMed Central

Unciti-Broceta, Juan D.; Arias, José L.; Maceira, José; Soriano, Miguel; Ortiz-González, Matilde; Hernández-Quero, José; Muñóz-Torres, Manuel; de Koning, Harry P.; Magez, Stefan; Garcia-Salcedo, José A.

2015-01-01

African trypanosomiasis is a deadly neglected disease caused by the extracellular parasite Trypanosoma brucei. Current therapies are characterized by high drug toxicity and increasing drug resistance mainly associated with loss-of-function mutations in the transporters involved in drug import. The introduction of new antiparasitic drugs into therapeutic use is a slow and expensive process. In contrast, specific targeting of existing drugs could represent a more rapid and cost-effective approach for neglected disease treatment, impacting through reduced systemic toxicity and circumventing resistance acquired through impaired compound uptake. We have generated nanoparticles of chitosan loaded with the trypanocidal drug pentamidine and coated by a single domain nanobody that specifically targets the surface of African trypanosomes. Once loaded into this nanocarrier, pentamidine enters trypanosomes through endocytosis instead of via classical cell surface transporters. The curative dose of pentamidine-loaded nanobody-chitosan nanoparticles was 100-fold lower than pentamidine alone in a murine model of acute African trypanosomiasis. Crucially, this new formulation displayed undiminished in vitro and in vivo activity against a trypanosome cell line resistant to pentamidine as a result of mutations in the surface transporter aquaglyceroporin 2. We conclude that this new drug delivery system increases drug efficacy and has the ability to overcome resistance to some anti-protozoal drugs. PMID:26110623

Identification of Genetic Polymorphisms of CYP2W1 in the Three Main Chinese Ethnicities: Han, Tibetan, and Uighur.

PubMed

Li, Yanwei; Kang, Xing; Yang, Ge; Dai, Penggao; Chen, Chao; Wang, Huijuan

2016-09-01

CYP2W1 is an orphan member of the cytochrome P450 superfamily. Recently, CYP2W1 has gained great research interest because of its unknown enzymatic function and tumor-specific expression property. This study aims to investigate the genetic polymorphisms of the CYP2W1 gene in Chinese populations and explore the functions of the detected variants. All of the nine exons and exon-intron junction regions of the CYP2W1 gene were sequenced in 150 Chinese subjects, including 50 Han Chinese, 50 Tibetans, and 50 Uighurs. A total of 26 genetic variants were identified in this study, and 19 polymorphisms were detected in each population. Frequency comparison between populations showed that nine variants exhibited significantly different allelic distributions. A total of 12 different haplotypes were inferred from 150 samples by using the genotype data of nine exonic variants found in this study. CYP2W1*1A, *1B, *2, *4, and *6 were detected as the main alleles/haplotypes. Moreover, one, three, and two ethnically specific haplotypes were observed in the Han, Tibetan, and Uighur samples, respectively. Then, the effects of four detected missense mutations (Ala181Thr, Gly376Ser, Val432Ile, and Pro488Leu) on the CYP2W1 protein function were predicted using three in silico tools: Polymorphism Phenotyping v2, Sorts Intolerant from Tolerant, and MutationTaster. The results showed that Gly376Ser and Pro488Leu may have deleterious effects. In summary, this study showed that the genetic pattern of CYP2W1 is interethnically different among the three Chinese populations, and this finding can extend our understanding of population genetics of CYP2W1 in the Chinese population. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

Genetic Ancestry-Smoking Interactions and Lung Function in African Americans: A Cohort Study

PubMed Central

Colangelo, Laura A.; Williams, L. Keoki; Sen, Saunak; Kritchevsky, Stephen B.; Meibohm, Bernd; Galanter, Joshua; Hu, Donglei; Gignoux, Christopher R.; Liu, Yongmei; Harris, Tamara B.; Ziv, Elad; Zmuda, Joseph; Garcia, Melissa; Leak, Tennille S.; Foreman, Marilyn G.; Smith, Lewis J.; Fornage, Myriam; Liu, Kiang; Burchard, Esteban G.

2012-01-01

Background Smoking tobacco reduces lung function. African Americans have both lower lung function and decreased metabolism of tobacco smoke compared to European Americans. African ancestry is also associated with lower pulmonary function in African Americans. We aimed to determine whether African ancestry modifies the association between smoking and lung function and its rate of decline in African Americans. Methodology/Principal Findings We evaluated a prospective ongoing cohort of 1,281 African Americans participating in the Health, Aging, and Body Composition (Health ABC) Study initiated in 1997. We also examined an ongoing prospective cohort initiated in 1985 of 1,223 African Americans in the Coronary Artery Disease in Young Adults (CARDIA) Study. Pulmonary function and tobacco smoking exposure were measured at baseline and repeatedly over the follow-up period. Individual genetic ancestry proportions were estimated using ancestry informative markers selected to distinguish European and West African ancestry. African Americans with a high proportion of African ancestry had lower baseline forced expiratory volume in one second (FEV1) per pack-year of smoking (−5.7 ml FEV1/ smoking pack-year) compared with smokers with lower African ancestry (−4.6 ml in FEV1/ smoking pack-year) (interaction P value  = 0.17). Longitudinal analyses revealed a suggestive interaction between smoking, and African ancestry on the rate of FEV1 decline in Health ABC and independently replicated in CARDIA. Conclusions/Significance African American individuals with a high proportion of African ancestry are at greater risk for losing lung function while smoking. PMID:22737244

African-American Men with Gleason Score 3+3=6 Prostate Cancer Produce Less Prostate Specific Antigen than Caucasian Men: A Potential Impact on Active Surveillance.

PubMed

Kryvenko, Oleksandr N; Balise, Raymond; Soodana Prakash, Nachiketh; Epstein, Jonathan I

2016-02-01

We assess the difference in prostate specific antigen production between African-American and Caucasian men with Gleason score 3+3=6 prostate cancer. We measured tumor volume in 414 consecutive radical prostatectomies from men with National Comprehensive Cancer Network(®) low risk prostate cancer (348 Caucasian, 66 African-American) who had Gleason score 3+3=6 disease at radical prostatectomy. We then compared clinical presentation, pathological findings, prostate specific antigen, prostate specific antigen density and prostate specific antigen mass (an absolute amount of prostate specific antigen in patient's circulation) between African-American and Caucasian men. The t-test and Wilcoxon rank sum were used for comparison of means. African-American and Caucasian men had similar clinical findings based on age, body mass index and prostate specific antigen. There were no statistically significant differences between the dominant tumor nodule volume and total tumor volume (mean 0.712 vs 0.665 cm(3), p=0.695) between African-American and Caucasian men. Prostates were heavier in African-American men (mean 55.4 vs 46.3 gm, p <0.03). Despite the significantly greater weight of benign prostate tissue contributing to prostate specific antigen in African-American men, prostate specific antigen mass was not different from that of Caucasian men (mean 0.55 vs 0.558 μg, p=0.95). Prostate specific antigen density was significantly less in African-American men due to larger prostates (mean 0.09 vs 0.105, p <0.02). African-American men with Gleason score 3+3=6 prostate cancer produce less prostate specific antigen than Caucasian men. African-American and Caucasian men had equal serum prostate specific antigen and prostate specific antigen mass despite significantly larger prostates in African-American men with all other parameters, particularly total tumor volume, being the same. This finding has practical implications in T1c cases diagnosed with prostate cancer due to prostate specific antigen screening. Lowering the prostate specific antigen density threshold in African-American men may account for this disparity, particularly in selecting patients for active surveillance programs. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

The effect of the COMT val(158)met polymorphism on neural correlates of semantic verbal fluency.

PubMed

Krug, Axel; Markov, Valentin; Sheldrick, Abigail; Krach, Sören; Jansen, Andreas; Zerres, Klaus; Eggermann, Thomas; Stöcker, Tony; Shah, N Jon; Kircher, Tilo

2009-12-01

Variation in the val(158)met polymorphism of the COMT gene has been found to be associated with cognitive performance. In functional neuroimaging studies, this dysfunction has been linked to signal changes in prefrontal areas. Given the complex modulation and functional heterogeneity of frontal lobe systems, further specification of COMT gene-related phenotypes differing in prefrontally mediated cognitive performance are of major interest. Eighty healthy individuals (54 men, 26 women; mean age 23.3 years) performed an overt semantic verbal fluency task while brain activation was measured with functional magnetic resonance imaging (fMRI). COMT val(158)met genotype was determined and correlated with brain activation measured with fMRI during the task. Although there were no differences in performance, brain activation in the left inferior frontal gyrus [Brodmann area 10] was positively correlated with the number of val alleles in the COMT gene. COMT val(158)met status modulates brain activation during the language production on a semantic level in an area related to executive functions.

A Cell-surface Phylome for African Trypanosomes

PubMed Central

Jackson, Andrew P.; Allison, Harriet C.; Barry, J. David; Field, Mark C.; Hertz-Fowler, Christiane; Berriman, Matthew

2013-01-01

The cell surface of Trypanosoma brucei, like many protistan blood parasites, is crucial for mediating host-parasite interactions and is instrumental to the initiation, maintenance and severity of infection. Previous comparisons with the related trypanosomatid parasites T. cruzi and Leishmania major suggest that the cell-surface proteome of T. brucei is largely taxon-specific. Here we compare genes predicted to encode cell surface proteins of T. brucei with those from two related African trypanosomes, T. congolense and T. vivax. We created a cell surface phylome (CSP) by estimating phylogenies for 79 gene families with putative surface functions to understand the more recent evolution of African trypanosome surface architecture. Our findings demonstrate that the transferrin receptor genes essential for bloodstream survival in T. brucei are conserved in T. congolense but absent from T. vivax and include an expanded gene family of insect stage-specific surface glycoproteins that includes many currently uncharacterized genes. We also identify species-specific features and innovations and confirm that these include most expression site-associated genes (ESAGs) in T. brucei, which are absent from T. congolense and T. vivax. The CSP presents the first global picture of the origins and dynamics of cell surface architecture in African trypanosomes, representing the principal differences in genomic repertoire between African trypanosome species and provides a basis from which to explore the developmental and pathological differences in surface architectures. All data can be accessed at: http://www.genedb.org/Page/trypanosoma_surface_phylome. PMID:23556014

Neuropsychopharmacology and Neurogenetic Aspects of Executive Functioning: Should Reward Gene Polymorphisms Constitute a Diagnostic Tool to Identify Individuals at Risk for Impaired Judgment?

PubMed Central

Bowirrat, Abdalla; Chen, Thomas JH; Oscar-Berman, Marlene; Madigan, Margaret; Chen, Amanda LH; Bailey, John A.; Braverman, Eric R.; Kerner, Mallory; Giordano, John; Morse, Siohban; Downs, B. William; Waite, Roger L.; Fornari, Frank; Armaly, Zaher; Blum, Kenneth

2013-01-01

Executive functions are processes that act in harmony to control behaviors necessary for maintaining focus and achieving outcomes. Executive dysfunction in neuropsychiatric disorders is attributed to structural or functional pathology of brain networks involving prefrontal cortex (PFC) and its connections with other brain regions. The PFC receives innervations from different neurons associated with a number of neurotransmitters, especially dopamine (DA). Here we review findings on the contribution of PFC DA to higher-order cognitive and emotional behaviors. We suggest examination of multifactorial interactions of an individual’s genetic history, along with environmental risk factors, can assist in the characterization of executive functioning for that individual. Based upon the results of genetic studies we also propose genetic mapping as a probable diagnostic tool serving as a therapeutic adjunct for augmenting executive functioning capabilities. We conclude that preservation of the neurological underpinnings of executive functions requires the integrity of complex neural systems including the influence of specific genes and associated polymorphisms to provide adequate neurotransmission. PMID:22371275

Neuropsychopharmacology and neurogenetic aspects of executive functioning: should reward gene polymorphisms constitute a diagnostic tool to identify individuals at risk for impaired judgment?

PubMed

Bowirrat, Abdalla; Chen, Thomas J H; Oscar-Berman, Marlene; Madigan, Margaret; Chen, Amanda Lh; Bailey, John A; Braverman, Eric R; Kerner, Mallory; Giordano, John; Morse, Siobhan; Downs, B William; Waite, Roger L; Fornari, Frank; Armaly, Zaher; Blum, Kenneth

2012-04-01

Executive functions are processes that act in harmony to control behaviors necessary for maintaining focus and achieving outcomes. Executive dysfunction in neuropsychiatric disorders is attributed to structural or functional pathology of brain networks involving prefrontal cortex (PFC) and its connections with other brain regions. The PFC receives innervations from different neurons associated with a number of neurotransmitters, especially dopamine (DA). Here we review findings on the contribution of PFC DA to higher-order cognitive and emotional behaviors. We suggest that examination of multifactorial interactions of an individual's genetic history, along with environmental risk factors, can assist in the characterization of executive functioning for that individual. Based upon the results of genetic studies, we also propose genetic mapping as a probable diagnostic tool serving as a therapeutic adjunct for augmenting executive functioning capabilities. We conclude that preservation of the neurological underpinnings of executive functions requires the integrity of complex neural systems including the influence of specific genes and associated polymorphisms to provide adequate neurotransmission.

Effects of BDNF polymorphisms on antidepressant action.

PubMed

Tsai, Shih-Jen; Hong, Chen-Jee; Liou, Ying-Jay

2010-12-01

Evidence suggests that the down-regulation of the signaling pathway involving brain-derived neurotrophic factor (BDNF), a molecular element known to regulate neuronal plasticity and survival, plays an important role in the pathogenesis of major depression. The restoration of BDNF activity induced by antidepressant treatment has been implicated in the antidepressant therapeutic mechanism. Because there is variability among patients with major depressive disorder in terms of response to antidepressant treatment and since genetic factors may contribute to this inter-individual variability in antidepressant response, pharmacogenetic studies have tested the associations between genetic polymorphisms in candidate genes related to antidepressant therapeutic action. In human BDNF gene, there is a common functional polymorphism (Val66Met) in the pro-region of BDNF, which affects the intracellular trafficking of proBDNF. Because of the potentially important role of BDNF in the antidepressant mechanism, many pharmacogenetic studies have tested the association between this polymorphism and the antidepressant therapeutic response, but they have produced inconsistent results. A recent meta-analysis of eight studies, which included data from 1,115 subjects, suggested that the Val/Met carriers have increased antidepressant response in comparison to Val/Val homozygotes, particularly in the Asian population. The positive molecular heterosis effect (subjects heterozygous for a specific genetic polymorphism show a significantly greater effect) is compatible with animal studies showing that, although BDNF exerts an antidepressant effect, too much BDNF may have a detrimental effect on mood. Several recommendations are proposed for future antidepressant pharmacogenetic studies of BDNF, including the consideration of multiple polymorphisms and a haplotype approach, gene-gene interaction, a single antidepressant regimen, controlling for age and gender interactions, and pharmacogenetic effects on specific depressive symptom-clusters.

Comparative genomics of the mimicry switch in Papilio dardanus.

PubMed

Timmermans, Martijn J T N; Baxter, Simon W; Clark, Rebecca; Heckel, David G; Vogel, Heiko; Collins, Steve; Papanicolaou, Alexie; Fukova, Iva; Joron, Mathieu; Thompson, Martin J; Jiggins, Chris D; ffrench-Constant, Richard H; Vogler, Alfried P

2014-07-22

The African Mocker Swallowtail, Papilio dardanus, is a textbook example in evolutionary genetics. Classical breeding experiments have shown that wing pattern variation in this polymorphic Batesian mimic is determined by the polyallelic H locus that controls a set of distinct mimetic phenotypes. Using bacterial artificial chromosome (BAC) sequencing, recombination analyses and comparative genomics, we show that H co-segregates with an interval of less than 500 kb that is collinear with two other Lepidoptera genomes and contains 24 genes, including the transcription factor genes engrailed (en) and invected (inv). H is located in a region of conserved gene order, which argues against any role for genomic translocations in the evolution of a hypothesized multi-gene mimicry locus. Natural populations of P. dardanus show significant associations of specific morphs with single nucleotide polymorphisms (SNPs), centred on en. In addition, SNP variation in the H region reveals evidence of non-neutral molecular evolution in the en gene alone. We find evidence for a duplication potentially driving physical constraints on recombination in the lamborni morph. Absence of perfect linkage disequilibrium between different genes in the other morphs suggests that H is limited to nucleotide positions in the regulatory and coding regions of en. Our results therefore support the hypothesis that a single gene underlies wing pattern variation in P. dardanus.

Regulatory polymorphisms modulate the expression of HLA class II molecules and promote autoimmunity

PubMed Central

Raj, Prithvi; Rai, Ekta; Song, Ran; Khan, Shaheen; Wakeland, Benjamin E; Viswanathan, Kasthuribai; Arana, Carlos; Liang, Chaoying; Zhang, Bo; Dozmorov, Igor; Carr-Johnson, Ferdicia; Mitrovic, Mitja; Wiley, Graham B; Kelly, Jennifer A; Lauwerys, Bernard R; Olsen, Nancy J; Cotsapas, Chris; Garcia, Christine K; Wise, Carol A; Harley, John B; Nath, Swapan K; James, Judith A; Jacob, Chaim O; Tsao, Betty P; Pasare, Chandrashekhar; Karp, David R; Li, Quan Zhen; Gaffney, Patrick M; Wakeland, Edward K

2016-01-01

Targeted sequencing of sixteen SLE risk loci among 1349 Caucasian cases and controls produced a comprehensive dataset of the variations causing susceptibility to systemic lupus erythematosus (SLE). Two independent disease association signals in the HLA-D region identified two regulatory regions containing 3562 polymorphisms that modified thirty-seven transcription factor binding sites. These extensive functional variations are a new and potent facet of HLA polymorphism. Variations modifying the consensus binding motifs of IRF4 and CTCF in the XL9 regulatory complex modified the transcription of HLA-DRB1, HLA-DQA1 and HLA-DQB1 in a chromosome-specific manner, resulting in a 2.5-fold increase in the surface expression of HLA-DR and DQ molecules on dendritic cells with SLE risk genotypes, which increases to over 4-fold after stimulation. Similar analyses of fifteen other SLE risk loci identified 1206 functional variants tightly linked with disease-associated SNPs and demonstrated that common disease alleles contain multiple causal variants modulating multiple immune system genes. DOI: http://dx.doi.org/10.7554/eLife.12089.001 PMID:26880555

[Association of I/D and -786 Polymorphisms of ACE and NOS3 Genes With Features of the Course of Ischemic Heart Disease and Diabetes Mellitus Type 2].

PubMed

Afanasiev, S A; Muslimova, E F; Rebrov, T Y; Sergienko, T N; Repin, A N

2016-09-01

to study relationship of ACE insertion-deletion (I/D) polymorphism and NOS3 T-786C polymorphism with characteristics of the course of ischemic heart disease (IHD) at the background of diabetes mellitus. Were examined 114 patients with IHD, 29.8% of patients had type 2 diabetes mellitus. ACE and NOS3 polymorphisms were determined by allele-specific polymerase chain reaction with primers by "Lytech". Patients with combined pathology belonged to older age group, had increased frequency of obesity and predominance of functional class II chronic heart failure. In this group we detected association of D allele of the ACE gene with higher frequency of dyslipidemia and obesity. Among patients with IHD without diabetes we observed associations of ACE I/D and NOS3 T-786C polymorphisms (close and moderate, respectively) with severity of effort angina. We also found that frequency of dyslipidemia among carriers of II and TT genotypes was lower than among carriers of other genotypes. Presence of type 2 diabetes as background pathology leads to a change of character of association of ACE I/D and NOS3 T-786C polymorphisms with clinical characteristics of patients with IHD.

Gender-specific association of the plasminogen activator inhibitor-1 4G/5G polymorphism with central arterial blood pressure.

PubMed

Björck, Hanna M; Eriksson, Per; Alehagen, Urban; De Basso, Rachel; Ljungberg, Liza U; Persson, Karin; Dahlström, Ulf; Länne, Toste

2011-07-01

The functional plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism has previously been associated with hypertension. In recent years, central blood pressure, rather than brachial has been argued a better measure of cardiovascular damage and clinical outcome. The aim of this study was to investigate the possible influence of the 4G/5G polymorphism on central arterial blood pressure in a cohort of elderly individuals. We studied 410 individuals, 216 men and 194 women, aged 70-88. Central pressures and pulse waveforms were calculated from the radial artery pressure waveform by the use of the SphygmoCor system and a generalized transfer function. Brachial pressure was recorded using oscillometric technique (Dinamap, Critikon, Tampa, FL). PAI-1 antigen was determined in plasma. The results showed that central pressures were higher in women carrying the PAI-1 4G/4G genotype compared to female carriers of the 5G/5G genotype, (P = 0.025, P = 0.002, and P = 0.002 for central systolic-, diastolic-, and mean arterial pressure, respectively). The association remained after adjustment for potentially confounding factors related to hypertension. No association of the PAI-1 genotype with blood pressure was found in men. Multiple regression analysis revealed an association between PAI-1 genotype and plasma PAI-1 levels (P = 0.048). Our findings show a gender-specific association of the PAI-1 4G/5G polymorphism with central arterial blood pressure. The genotype effect was independent of other risk factors related to hypertension, suggesting that impaired fibrinolytic potential may play an important role in the development of central hypertension in women.

Loci associated with skin pigmentation identified in African populations

PubMed Central

Crawford, Nicholas G.; Kelly, Derek E.; Hansen, Matthew E. B.; Beltrame, Marcia H.; Fan, Shaohua; Bowman, Shanna L.; Jewett, Ethan; Ranciaro, Alessia; Thompson, Simon; Lo, Yancy; Pfeifer, Susanne P.; Jensen, Jeffrey D.; Campbell, Michael C.; Beggs, William; Hormozdiari, Farhad; Mpoloka, Sununguko Wata; Mokone, Gaonyadiwe George; Nyambo, Thomas; Meskel, Dawit Wolde; Belay, Gurja; Haut, Jake; Rothschild, Harriet; Zon, Leonard; Zhou, Yi; Kovacs, Michael A.; Xu, Mai; Zhang, Tongwu; Bishop, Kevin; Sinclair, Jason; Rivas, Cecilia; Elliot, Eugene; Choi, Jiyeon; Li, Shengchao A.; Hicks, Belynda; Burgess, Shawn; Abnet, Christian; Watkins-Chow, Dawn E.; Oceana, Elena; Song, Yun S.; Eskin, Eleazar; Brown, Kevin M.; Marks, Michael S.; Loftus, Stacie K.; Pavan, William J.; Yeager, Meredith; Chanock, Stephen; Tishkoff, Sarah

2017-01-01

Despite the wide range of skin pigmentation in humans, little is known about its genetic basis in global populations. Examining ethnically diverse African genomes, we identify variants in or near SLC24A5, MFSD12, DDB1, TMEM138, OCA2 and HERC2 that are significantly associated with skin pigmentation. Genetic evidence indicates that the light pigmentation variant at SLC24A5 was introduced into East Africa by gene flow from non-Africans. At all other loci, variants associated with dark pigmentation in Africans are identical by descent in southern Asian and Australo-Melanesian populations. Functional analyses indicate that MFSD12 encodes a lysosomal protein that affects melanogenesis in zebrafish and mice, and that mutations in melanocyte-specific regulatory regions near DDB1/TMEM138 correlate with expression of UV response genes under selection in Eurasians. PMID:29025994

Genetic Polymorphisms of Metastasis Suppressor Gene NME1 and Breast Cancer Survival

PubMed Central

Qu, Shimian; Long, Jirong; Cai, Qiuyin; Shu, Xiao-Ou; Cai, Hui; Gao, Yu-Tang; Zheng, Wei

2009-01-01

Purpose Ample evidence supports an important role of tumor metastasis suppressor genes in cancer metastatic processes. We evaluated the association of genetic polymorphisms of tumor metastasis suppressor gene NME1 with breast cancer prognosis in a follow-up study of patients with primary breast cancer and further investigated the functions of these polymorphisms. Experimental Design NME1 genotypes were analyzed in a cohort of 1134 breast cancer patients recruited as part of the Shanghai Breast Cancer Study who were followed for a median of 7.1 years. In vitro biochemical analyses were carried out to examine the function of NME1 gene polymorphisms. Results Single nucleotide polymorphisms (SNPs) in the promoter region of the NME1 gene were found to be associated with breast cancer prognosis. Patients carrying the C allele in rs16949649 were associated with higher breast cancer-specific mortality (HR =1.4, 95% CI =1.1–1.9) as compared to those carrying the wild-type allele, and the association was more evident in patients with an early stage cancer (HR=1.7, 95% CI =1.2–2.5). SNP rs2302254 was also associated with breast cancer prognosis, and the association was statistically significant for the risk of breast cancer relapse, metastasis, and death (HR=1.3, 95% CI, 1.0–1.6). In vitro biochemical analyses showed that minor alleles in rs2302254 and rs3760468, which is in strong linkage disequilibrium with rs16949646, altered nuclear proteins binding capacity and reduced NME1 promoter activity, supporting the results from an association study of these SNPs with breast cancer survival. Conclusion Promoter polymorphisms in the NME1 gene may alter its expression and influence breast cancer survival. PMID:18676749

Association between FOXP3 polymorphisms and vitiligo in a Han Chinese population.

PubMed

Song, P; Wang, X-W; Li, H-X; Li, K; Liu, L; Wei, C; Jian, Z; Yi, X-L; Li, Q; Wang, G; Li, C-Y; Gao, T-W

2013-09-01

Vitiligo is an autoimmune chronic depigmentation disorder caused by melanocyte loss. Previous studies found that CD4(+)CD25(+) regulatory T-cell (Treg) dysfunction was involved in the pathogenesis of vitiligo and that gene polymorphisms in forkhead box P3 (FOXP3) - a master regulator of Treg development and function - were associated with susceptibility to some autoimmune disorders. Therefore, we hypothesized that functional polymorphisms of the FOXP3 gene might be associated with vitiligo via dysregulation of Treg cells. To evaluate whether FOXP3 polymorphisms are associated with vitiligo risk. In this hospital-based case-control study of 682 patients with vitiligo and 682 vitiligo-free age- and sex-matched controls, we genotyped three single nucleotide polymorphisms (SNPs) of the FOXP3 gene - rs2232365, rs3761548 and rs5902434 - by performing polymerase chain reaction with sequence-specific primers (PCR-SSP). Significantly increased vitiligo risk was associated with the rs2232365 GG [odds ratio (OR) 1·68, 95% confidence interval (CI) 1·17-2·39, P = 0·004] and rs3761548 AA (OR 1·82, 95% CI 1·10-3·01, P = 0·033) genotypes compared with the rs2232365 AA and rs3761548 CC genotypes. On combined analysis of these three variant alleles, we found that individuals carrying 2-6 variant alleles had significantly increased vitiligo risk (OR 1·34, 95% CI 1·08-1·66). This risk was more pronounced in the following subgroups: age > 20 years, male sex, active vitiligo, nonsegmental vitiligo and other accompanying autoimmune diseases. FOXP3 gene polymorphisms contributed to vitiligo risk in a Han Chinese population. © 2013 The Authors BJD © 2013 British Association of Dermatologists.

Vitamin D receptor variants and uncontrolled asthma.

PubMed

Hutchinson, K; Kerley, C P; Faul, J; Greally, P; Coghlan, D; Louw, M; Elnazir, B; Rochev, Y

2017-11-28

Background. Asthma is a common childhood respiratory disease, affecting around 20% of Irish children. In other populations, vitamin D receptor (VDR) polymorphisms have been associated with asthma risk. We aimed to investigate the association between 2 VDR polymorphisms and uncontrolled paediatric asthma. Methods. 44 asthmatic children and 57 healthy volunteers were studied. The VDR TaqI gene variant in exon 9 (T/C) (rs731236) and ApaI (rs7975232) in intron 8 (C/T) were determined, using TaqMan® Assays. The lung function, serum 25-hydroxyvitamin D (25OHD) levels and other biomarkers of allergy, immunity, airway and systemic inflammation were as-sessed. Results. The distribution of T and C alleles and genotype frequencies differed significantly between asthmatics and controls for both polymorphisms (p < 0.05). A significant association was found between both TaqI [OR = 2.37, 95% CI (1.27 - 4.45), p = 0.007] and ApaI polymorphisms, and asthma risk [OR = 2.93, 95% CI (1.62 - 5.3), p = 0.0004]. No association was observed between genotypes and 25OHD levels, lung function and other biomarkers, with the exception of Interleukin-10 (IL-10) and white blood cells count (WBC). IL-10 levels were lower in asthmatics with TC genotype for TaqI polymorphism (p < 0.01) and were higher in patients with TT genotype for ApaI (p < 0.01). WBC were higher in patients with TC and CC genotypes for TaqI (p < 0.05) and lower in TT genotype for ApaI (p < 0.05). Conclusion. TaqI and ApaI polymorphisms are associated with asthma in Irish children. Further studies are warranted to investigate the importance of decreased IL-10 levels in paediatric asthmatics with specific genotypes.

Evaluation of the TREX1 gene in a large multi-ancestral lupus cohort

PubMed Central

Namjou, Bahram; Kothari, Parul H.; Kelly, Jennifer A.; Glenn, Stuart B.; Ojwang, Joshua O.; Adler, Adam; Alarcón-Riquelme, Marta E.; Gallant, Caroline J.; Boackle, Susan A.; Criswell, Lindsey A.; Kimberly, Robert P.; Brown, Elizabeth; Edberg, Jeffrey; Stevens, Anne M.; Jacob, Chaim O.; Tsao, Betty P.; Gilkeson, Gary S.; Kamen, Diane L.; Merrill, Joan T.; Petri, Michelle; Goldman, Rosalind Ramsey; Vila, Luis M.; Anaya, Juan-Manuel; Niewold, Timothy B.; Martin, Javier; Pons-Estel, Bernardo A.; Sabio, Jose M.; Callejas, Jose L.; Vyse, Timothy J.; Bae, Sang-Cheol; Perrino, Fred W.; Freedman, Barry I.; Scofield, R. Hal; Moser, Kathy L.; Gaffney, Patrick M.; James, Judith A.; Langefeld, Carl D.; Kaufman, Kenneth M.; Harley, John B.; Atkinson, John P.

2011-01-01

Systemic Lupus Erythematosus (SLE) is a prototypic autoimmune disorder with a complex pathogenesis in which genetic, hormonal and environmental factors play a role. Rare mutations in the TREX1 gene, the major mammalian 3′-5′ exonuclease, have been reported in sporadic SLE cases. Some of these mutations have also been identified in a rare pediatric neurologic condition featuring an inflammatory encephalopathy known as Aicardi-Goutières syndrome (AGS). We sought to investigate the frequency of these mutations in a large multi-ancestral cohort of SLE cases and controls. Methods Forty single-nucleotide polymorphisms (SNPs), including both common and rare variants, across the TREX1 gene were evaluated in ∼8370 patients with SLE and ∼7490 control subjects. Stringent quality control procedures were applied and principal components and admixture proportions were calculated to identify outliers for removal from analysis. Population-based case-control association analyses were performed. P values, false discovery rate q values, and odds ratios with 95% confidence intervals were calculated. Results The estimated frequency of TREX1 mutations in our lupus cohort was 0.5%. Five heterozygous mutations were detected at the Y305C polymorphism in European lupus cases but none were observed in European controls. Five African cases incurred heterozygous mutations at the E266G polymorphism and, again, none were observed in the African controls. A rare homozygous R114H mutation was identified in one Asian SLE patient whereas all genotypes at this mutation in previous reports for SLE were heterozygous. Analysis of common TREX1 SNPs (MAF >10%) revealed a relatively common risk haplotype in European SLE patients with neurologic manifestations, especially seizures, with a frequency of 58% in lupus cases compared to 45% in normal controls (p=0.0008, OR=1.73, 95% CI=1.25-2.39). Finally, the presence or absence of specific autoantibodies in certain populations produced significant genetic associations. For example, a strong association with anti-nRNP was observed in the European cohort at a coding synonymous variant rs56203834 (p=2.99E-13, OR=5.2, 95% CI=3.18-8.56). Conclusion Our data confirm and expand previous reports and provide additional support for the involvement of TREX1 in lupus pathogenesis. PMID:21270825

Cis-Regulatory Variants Affect CHRNA5 mRNA Expression in Populations of African and European Ancestry

PubMed Central

Wang, Jen-Chyong; Spiegel, Noah; Bertelsen, Sarah; Le, Nhung; McKenna, Nicholas; Budde, John P.; Harari, Oscar; Kapoor, Manav; Brooks, Andrew; Hancock, Dana; Tischfield, Jay; Foroud, Tatiana; Bierut, Laura J.; Steinbach, Joe Henry; Edenberg, Howard J.; Traynor, Bryan J.; Goate, Alison M.

2013-01-01

Variants within the gene cluster encoding α3, α5, and β4 nicotinic receptor subunits are major risk factors for substance dependence. The strongest impact on risk is associated with variation in the CHRNA5 gene, where at least two mechanisms are at work: amino acid variation and altered mRNA expression levels. The risk allele of the non-synonymous variant (rs16969968; D398N) primarily occurs on the haplotype containing the low mRNA expression allele. In populations of European ancestry, there are approximately 50 highly correlated variants in the CHRNA5-CHRNA3-CHRNB4 gene cluster and the adjacent PSMA4 gene region that are associated with CHRNA5 mRNA levels. It is not clear which of these variants contribute to the changes in CHRNA5 transcript level. Because populations of African ancestry have reduced linkage disequilibrium among variants spanning this gene cluster, eQTL mapping in subjects of African ancestry could potentially aid in defining the functional variants that affect CHRNA5 mRNA levels. We performed quantitative allele specific gene expression using frontal cortices derived from 49 subjects of African ancestry and 111 subjects of European ancestry. This method measures allele-specific transcript levels in the same individual, which eliminates other biological variation that occurs when comparing expression levels between different samples. This analysis confirmed that substance dependence associated variants have a direct cis-regulatory effect on CHRNA5 transcript levels in human frontal cortices of African and European ancestry and identified 10 highly correlated variants, located in a 9 kb region, that are potential functional variants modifying CHRNA5 mRNA expression levels. PMID:24303001

The genomic substrate for adaptive radiation in African cichlid fish.

PubMed

Brawand, David; Wagner, Catherine E; Li, Yang I; Malinsky, Milan; Keller, Irene; Fan, Shaohua; Simakov, Oleg; Ng, Alvin Y; Lim, Zhi Wei; Bezault, Etienne; Turner-Maier, Jason; Johnson, Jeremy; Alcazar, Rosa; Noh, Hyun Ji; Russell, Pamela; Aken, Bronwen; Alföldi, Jessica; Amemiya, Chris; Azzouzi, Naoual; Baroiller, Jean-François; Barloy-Hubler, Frederique; Berlin, Aaron; Bloomquist, Ryan; Carleton, Karen L; Conte, Matthew A; D'Cotta, Helena; Eshel, Orly; Gaffney, Leslie; Galibert, Francis; Gante, Hugo F; Gnerre, Sante; Greuter, Lucie; Guyon, Richard; Haddad, Natalie S; Haerty, Wilfried; Harris, Rayna M; Hofmann, Hans A; Hourlier, Thibaut; Hulata, Gideon; Jaffe, David B; Lara, Marcia; Lee, Alison P; MacCallum, Iain; Mwaiko, Salome; Nikaido, Masato; Nishihara, Hidenori; Ozouf-Costaz, Catherine; Penman, David J; Przybylski, Dariusz; Rakotomanga, Michaelle; Renn, Suzy C P; Ribeiro, Filipe J; Ron, Micha; Salzburger, Walter; Sanchez-Pulido, Luis; Santos, M Emilia; Searle, Steve; Sharpe, Ted; Swofford, Ross; Tan, Frederick J; Williams, Louise; Young, Sarah; Yin, Shuangye; Okada, Norihiro; Kocher, Thomas D; Miska, Eric A; Lander, Eric S; Venkatesh, Byrappa; Fernald, Russell D; Meyer, Axel; Ponting, Chris P; Streelman, J Todd; Lindblad-Toh, Kerstin; Seehausen, Ole; Di Palma, Federica

2014-09-18

Cichlid fishes are famous for large, diverse and replicated adaptive radiations in the Great Lakes of East Africa. To understand the molecular mechanisms underlying cichlid phenotypic diversity, we sequenced the genomes and transcriptomes of five lineages of African cichlids: the Nile tilapia (Oreochromis niloticus), an ancestral lineage with low diversity; and four members of the East African lineage: Neolamprologus brichardi/pulcher (older radiation, Lake Tanganyika), Metriaclima zebra (recent radiation, Lake Malawi), Pundamilia nyererei (very recent radiation, Lake Victoria), and Astatotilapia burtoni (riverine species around Lake Tanganyika). We found an excess of gene duplications in the East African lineage compared to tilapia and other teleosts, an abundance of non-coding element divergence, accelerated coding sequence evolution, expression divergence associated with transposable element insertions, and regulation by novel microRNAs. In addition, we analysed sequence data from sixty individuals representing six closely related species from Lake Victoria, and show genome-wide diversifying selection on coding and regulatory variants, some of which were recruited from ancient polymorphisms. We conclude that a number of molecular mechanisms shaped East African cichlid genomes, and that amassing of standing variation during periods of relaxed purifying selection may have been important in facilitating subsequent evolutionary diversification.

The Origins of African Plasmodium vivax; Insights from Mitochondrial Genome Sequencing

PubMed Central

Culleton, Richard; Coban, Cevayir; Zeyrek, Fadile Yildiz; Cravo, Pedro; Kaneko, Akira; Randrianarivelojosia, Milijaona; Andrianaranjaka, Voahangy; Kano, Shigeyuki; Farnert, Anna; Arez, Ana Paula; Sharp, Paul M.; Carter, Richard; Tanabe, Kazuyuki

2011-01-01

Plasmodium vivax, the second most prevalent of the human malaria parasites, is estimated to affect 75 million people annually. It is very rare, however, in west and central Africa, due to the high prevalence of the Duffy negative phenotype in the human population. Due to its rarity in Africa, previous studies on the phylogeny of world-wide P. vivax have suffered from insufficient samples of African parasites. Here we compare the mitochondrial sequence diversity of parasites from Africa with those from other areas of the world, in order to investigate the origin of present-day African P. vivax. Mitochondrial genome sequencing revealed relatively little polymorphism within the African population compared to parasites from the rest of the world. This, combined with sequence similarity with parasites from India, suggests that the present day African P. vivax population in humans may have been introduced relatively recently from the Indian subcontinent. Haplotype network analysis also raises the possibility that parasites currently found in Africa and South America may be the closest extant relatives of the ancestors of the current world population. Lines of evidence are adduced that this ancestral population may be from an ancient stock of P. vivax in Africa. PMID:22195007

The genomic substrate for adaptive radiation in African cichlid fish

PubMed Central

Malinsky, Milan; Keller, Irene; Fan, Shaohua; Simakov, Oleg; Ng, Alvin Y.; Lim, Zhi Wei; Bezault, Etienne; Turner-Maier, Jason; Johnson, Jeremy; Alcazar, Rosa; Noh, Hyun Ji; Russell, Pamela; Aken, Bronwen; Alföldi, Jessica; Amemiya, Chris; Azzouzi, Naoual; Baroiller, Jean-François; Barloy-Hubler, Frederique; Berlin, Aaron; Bloomquist, Ryan; Carleton, Karen L.; Conte, Matthew A.; D'Cotta, Helena; Eshel, Orly; Gaffney, Leslie; Galibert, Francis; Gante, Hugo F.; Gnerre, Sante; Greuter, Lucie; Guyon, Richard; Haddad, Natalie S.; Haerty, Wilfried; Harris, Rayna M.; Hofmann, Hans A.; Hourlier, Thibaut; Hulata, Gideon; Jaffe, David B.; Lara, Marcia; Lee, Alison P.; MacCallum, Iain; Mwaiko, Salome; Nikaido, Masato; Nishihara, Hidenori; Ozouf-Costaz, Catherine; Penman, David J.; Przybylski, Dariusz; Rakotomanga, Michaelle; Renn, Suzy C. P.; Ribeiro, Filipe J.; Ron, Micha; Salzburger, Walter; Sanchez-Pulido, Luis; Santos, M. Emilia; Searle, Steve; Sharpe, Ted; Swofford, Ross; Tan, Frederick J.; Williams, Louise; Young, Sarah; Yin, Shuangye; Okada, Norihiro; Kocher, Thomas D.; Miska, Eric A.; Lander, Eric S.; Venkatesh, Byrappa; Fernald, Russell D.; Meyer, Axel; Ponting, Chris P.; Streelman, J. Todd; Lindblad-Toh, Kerstin; Seehausen, Ole; Di Palma, Federica

2015-01-01

Cichlid fishes are famous for large, diverse and replicated adaptive radiations in the Great Lakes of East Africa. To understand the molecular mechanisms underlying cichlid phenotypic diversity, we sequenced the genomes and transcriptomes of five lineages of African cichlids: the Nile tilapia (Oreochromis niloticus), an ancestral lineage with low diversity; and four members of the East African lineage: Neolamprologus brichardi/pulcher (older radiation, Lake Tanganyika), Metriaclima zebra (recent radiation, Lake Malawi), Pundamilia nyererei (very recent radiation, Lake Victoria), and Astatotilapia burtoni (riverine species around Lake Tanganyika). We found an excess of gene duplications in the East African lineage compared to tilapia and other teleosts, an abundance of non-coding element divergence, accelerated coding sequence evolution, expression divergence associated with transposable element insertions, and regulation by novel microRNAs. In addition, we analysed sequence data from sixty individuals representing six closely related species from Lake Victoria, and show genome-wide diversifying selection on coding and regulatory variants, some of which were recruited from ancient polymorphisms. We conclude that a number of molecular mechanisms shaped East African cichlid genomes, and that amassing of standing variation during periods of relaxed purifying selection may have been important in facilitating subsequent evolutionary diversification. PMID:25186727

The genetic prehistory of southern Africa.

PubMed

Pickrell, Joseph K; Patterson, Nick; Barbieri, Chiara; Berthold, Falko; Gerlach, Linda; Güldemann, Tom; Kure, Blesswell; Mpoloka, Sununguko Wata; Nakagawa, Hirosi; Naumann, Christfried; Lipson, Mark; Loh, Po-Ru; Lachance, Joseph; Mountain, Joanna; Bustamante, Carlos D; Berger, Bonnie; Tishkoff, Sarah A; Henn, Brenna M; Stoneking, Mark; Reich, David; Pakendorf, Brigitte

2012-01-01

Southern and eastern African populations that speak non-Bantu languages with click consonants are known to harbour some of the most ancient genetic lineages in humans, but their relationships are poorly understood. Here, we report data from 23 populations analysed at over half a million single-nucleotide polymorphisms, using a genome-wide array designed for studying human history. The southern African Khoisan fall into two genetic groups, loosely corresponding to the northwestern and southeastern Kalahari, which we show separated within the last 30,000 years. We find that all individuals derive at least a few percent of their genomes from admixture with non-Khoisan populations that began ∼1,200 years ago. In addition, the East African Hadza and Sandawe derive a fraction of their ancestry from admixture with a population related to the Khoisan, supporting the hypothesis of an ancient link between southern and eastern Africa.

Association of the 5′-upstream regulatory region of the α7 nicotinic acetylcholine receptor subunit gene (CHRNA7) with schizophrenia

PubMed Central

Stephens, Sarah H.; Logel, Judith; Barton, Amanda; Franks, Alexis; Schultz, Jessica; Short, Margaret; Dickenson, Jane; James, Benjamin; Fingerlin, Tasha E.; Wagner, Brandie; Hodgkinson, Colin; Graw, Sharon; Ross, Randal G.; Freedman, Robert; Leonard, Sherry

2009-01-01

Background The α7 neuronal nicotinic acetylcholine receptor subunit gene (CHRNA7) is localized in a chromosomal region (15q14) linked to schizophrenia in multiple independent studies. CHRNA7 was selected as the best candidate gene in the region for a well-documented endophenotype of schizophrenia, the P50 sensory processing deficit, by genetic linkage and biochemical studies. Methods Subjects included Caucasian-Non Hispanic and African-American case-control subjects collected in Denver, and schizophrenic subjects from families in the NIMH Genetics Initiative on Schizophrenia. Thirty-five single nucleotide polymorphisms (SNPs) in the 5′-upstream regulatory region of CHRNA7 were genotyped for association with schizophrenia, and for smoking in schizophrenia. Results The rs3087454 SNP, located at position −1831 bp in the upstream regulatory region of CHRNA7, was significantly associated with schizophrenia in the case-control samples after multiple-testing correction (P = 0.0009, African American; P = 0.013, Caucasian-Non Hispanic); the association was supported in family members. There was nominal association of this SNP with smoking in schizophrenia. Conclusions The data support association of regulatory region polymorphisms in the CHRNA7 gene with schizophrenia. PMID:19181484

Structural polymorphism at LCR and its role in beta-globin gene regulation.

PubMed

Kukreti, Shrikant; Kaur, Harpreet; Kaushik, Mahima; Bansal, Aparna; Saxena, Sarika; Kaushik, Shikha; Kukreti, Ritushree

2010-09-01

Information on the secondary structures and conformational manifestations of eukaryotic DNA and their biological significance with reference to gene regulation and expression is limited. The human beta-globin gene Locus Control Region (LCR), a dominant regulator of globin gene expression, is a contiguous piece of DNA with five tissue-specific DNase I-hypersensitive sites (HSs). Since these HSs have a high density of transcription factor binding sites, structural interdependencies between HSs and different promoters may directly or indirectly regulate LCR functions. Mutations and SNPs may stabilize or destabilize the local secondary structures, affecting the gene expression by changes in the protein-DNA recognition patterns. Various palindromic or quasi-palindromic segments within LCR, could cause structural polymorphism and geometrical switching of DNA. This emphasizes the importance of understanding of the sequence-dependent variations of the DNA structure. Such structural motifs might act as regulatory elements. The local conformational variability of a DNA segment or action of a DNA specific protein is key to create and maintain active chromatin domains and affect transcription of various tissue specific beta-globin genes. We, summarize here the current status of beta-globin LCR structure and function. Further structural studies at molecular level and functional genomics might solve the regulatory puzzles that control the beta-globin gene locus. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Genetic findings and functional studies of human CYP3A5 single nucleotide polymorphisms in different ethnic groups.

PubMed

Lee, Su-Jun; Usmani, Khawja A; Chanas, Brian; Ghanayem, Burhan; Xi, Tina; Hodgson, Ernest; Mohrenweiser, Harvey W; Goldstein, Joyce A

2003-08-01

Genetic polymorphisms of cytochromes P450 (CYPs) are a principal reason for inter-individual variations in the metabolism of therapeutic drugs and environmental chemicals in humans. The present study identifies 34 single nucleotide polymorphisms (SNPs) of CYP3A5 including 27 previously unidentified SNPs by direct sequencing of the exons, intron-exon junctions and 5'-upstream region of CYP3A5 from 92 racially diverse individuals (24 Caucasians, 24 Africans, 24 Asians, and 20 individuals of unknown racial origin). Four new CYP3A5 SNPs produced coding changes: R28C, L82R, A337T, and F446S. CYP3A5 R28C occurred in African populations (allelic frequency of 4%). CYP3A5 A337T occurred in Asians (2% allelic frequency), CYP3A5 L82R (occurred in the racially unidentified group) and CYP3A5 F446S (identified in Caucasians with a 2% allelic frequency) were on an allele containing the splice change g.6986A>G known as CYP3A5*3. The newly identified allelic proteins were constructed by site-directed mutagenesis, expressed in Escherichia coli and purified. CYP3A5 L82R was expressed only as denatured CYP420, suggesting it may be unstable. CYP3A5*1 exhibited the highest maximal clearance for testosterone followed by CYP3A5 A337T > CYP3A5 R28C > CYP3A5 F446S. CYP3A5*1 exhibited a higher V(max) for nifedipine oxidation than CYP3A5 A337T > CYP3A5 R28C > CYP3A5 F446S. CYP3A5 A337T and CYP3A5 R28C exhibited a 42-64% lower V(max) for nifedipine oxidation than CYP3A5*1. CYP3A5 F446S exhibited a > 95% decrease in the intrinsic clearance for both 6beta-hydroxytestosterone and nifedipine oxidation. This study identifies four new potentially defective coding alleles. CYP3A5 F446S is predicted to be more catalytically defective than the splice change alone.

Pharmacogenetic Associations of β1-Adrenergic Receptor Polymorphisms With Cardiovascular Outcomes in the SPS3 Trial (Secondary Prevention of Small Subcortical Strokes).

PubMed

Magvanjav, Oyunbileg; McDonough, Caitrin W; Gong, Yan; McClure, Leslie A; Talbert, Robert L; Horenstein, Richard B; Shuldiner, Alan R; Benavente, Oscar R; Mitchell, Braxton D; Johnson, Julie A

2017-05-01

Functional polymorphisms (Ser49Gly and Arg389Gly) in ADRB1 have been associated with cardiovascular and β-blocker response outcomes. Herein we examined associations of these polymorphisms with major adverse cardiovascular events (MACE), with and without stratification by β-blocker treatment in patients with a history of stroke. Nine hundred and twenty-six participants of the SPS3 trial's (Secondary Prevention of Small Subcortical Strokes) genetic substudy with hypertension were included. MACE included stroke, myocardial infarction, and all-cause death. Kaplan-Meier and multivariable Cox regression analyses were used. Because the primary component of MACE was ischemic stroke, we tested the association of Ser49Gly with ischemic stroke among 41 475 individuals of European and African ancestry in the NINDS (National Institute of Neurological Disorders and Stroke) SiGN (Stroke Genetics Network). MACE was higher in carriers of the Gly49 allele than in those with the Ser49Ser genotype (10.5% versus 5.4%, log-rank P =0.005). Gly49 carrier status was associated with MACE (hazard ratio, 1.62; 95% confidence interval, 1.00-2.68) and ischemic stroke (hazard ratio, 1.81; 95% confidence interval, 1.01-3.23) in SPS3 and with small artery ischemic stroke (odds ratio, 1.14; 95% confidence interval, 1.03-1.26) in SiGN. In SPS3, β-blocker-treated Gly49 carriers had increased MACE versus non-β-blocker-treated individuals and noncarriers (hazard ratio, 2.03; 95% confidence interval, 1.20-3.45). No associations were observed with the Arg389Gly polymorphism. Among individuals with previous small artery ischemic stroke, the ADRB1 Gly49 polymorphism was associated with MACE, particularly small artery ischemic stroke, a risk that may be increased among β-blocker-treated individuals. Further research is needed to define β-blocker benefit among ischemic stroke patients by ADRB1 genotype. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306. © 2017 American Heart Association, Inc.

BCL11A Enhancer Haplotypes and Fetal Hemoglobin in Sickle Cell Anemia

PubMed Central

Sebastiani, P.; Farrell, J.J.; Alsultan, A.; Wang, S.; Edward, H. L.; Shappell, H.; Bae, H.; Milton, J. N.; Baldwin, C.T.; Al-Rubaish, A.M.; Naserullah, Z.; Al-Muhanna, F.; Alsuliman, A.; Patra, P. K.; Farrer, L.A.; Ngo, D.; Vathipadiekal, V.; Chui, D.H.K.; Al-Ali, A.K.; Steinberg, M.H.

2015-01-01

Background Fetal hemoglobin (HbF) levels in sickle cell anemia patients vary. We genotyped polymorphisms in the erythroid-specific enhancer of BCL11A to see if they might account for the very high HbF associated with the Arab-Indian (AI) haplotype and Benin haplotype of sickle cell anemia. Methods and Results Six BCL112A enhancer SNPs and their haplotypes were studied in Saudi Arabs from the Eastern Province and Indian patients with AI haplotype (HbF ~20%), African Americans (HbF ~7%), and Saudi Arabs from the Southwestern Province (HbF ~12%). Four SNPs (rs1427407, rs6706648, rs6738440, and rs7606173) and their haplotypes were consistently associated with HbF levels. The distributions of haplotypes differ in the 3 cohorts but not their genetic effects: the haplotype TCAG was associated with the lowest HbF level and the haplotype GTAC was associated with the highest HbF level and differences in HbF levels between carriers of these haplotypes in all cohorts was approximately 6%. Conclusions Common HbF BCL11A enhancer haplotypes in patients with African origin and AI sickle cell anemia have similar effects on HbF but they do not explain their differences in HbF. PMID:25703683

TGFB1 Functional Gene Polymorphisms (C-509T and T869C) in the Maternal Susceptibility to Pre-eclampsia in South Indian Women.

PubMed

Deepthi, Goske; Chaithri, Ponnaluri Kamakshi; Latha, Prasanna; Rani, Vital Usha; Rahman, Police Fazul; Jahan, Parveen

2015-10-01

Pre-eclampsia (PE), a pregnancy-specific vascular disorder characterized by hypertension and proteinuria, is hypothesized to be the result of inadequate placental angiogenesis with attendant systemic inflammation. The pleiotropic cytokine, Transforming Growth Factor-β1 (TGF-β1), is considered to be a key candidate gene in the molecular pathogenesis of PE by virtue of its ability to not only regulate angiogenesis and apoptosis of target cells, but also by acting as a master controller of Th1/Th2 cytokine balance and production of the anti-inflammatory peripheral regulatory T cells (FOXP3+ Tregs). Based on this presumption, we screened a total of 469 pregnant women from South India that include 239 patients with PE and 230 healthy controls for the two functional polymorphisms of TGFB1 gene (C-509T and T869C). The genotype frequencies of these two polymorphisms differed significantly between the PE and control groups (P = 0.01 and P = 0.002, for the TGFB1 C-509T and T869C polymorphisms, respectively). Under the over-dominant model, the CT genotype of the TGFB1 C509T polymorphism showed a high protective effect (P = 3e-04), while the TT genotype of the same variant appeared to be the predisposing genotype (P = 0.003). The T-T and C-C haplotypes were found to be the risk haplotypes blocks towards PE (OR = 4.72; P = 0.031, OR = 5.39; P = 0.03), respectively. Strong linkage disequilibrium was seen between the two polymorphisms. Our investigations revealed a significant influence of TGFB1 C-509T and T869C polymorphisms on the PE risk in South Indian women. The study represents one of the first of its kind from the Indian subcontinent. © 2015 The Foundation for the Scandinavian Journal of Immunology.

Human neutrophil antigen profiles in Banjar, Bugis, Champa, Jawa and Kelantan Malays in Peninsular Malaysia

PubMed Central

Manaf, Siti M.; NurWaliyuddin, Hanis Z.A.; Panneerchelvam, Sundararajulu; Zafarina, Zainuddin; Norazmi, Mohd N.; Chambers, Geoffrey K.; Edinur, Hisham A.

2015-01-01

Background Human neutrophil antigens (HNA) are polymorphic and immunogenic proteins involved in the pathogenesis of neonatal alloimmune neutropenia, transfusion-related acute lung injury (TRALI) and transfusion-related alloimmune neutropenia. The characterisation of HNA at a population level is important for predicting the risk of alloimmunisation associated with blood transfusion and gestation and for anthropological studies. Materials and methods Blood samples from 192 healthy, unrelated Malays were collected and genotyped using polymerase chain reaction-sequence specific primers (HNA-1, -3, -4) and polymerase chain reaction-restriction fragment length polymorphisms (HNA-5). The group comprised 30 Banjar, 37 Bugis, 51 Champa, 39 Jawa and 35 Kelantan Malays. Results The most common HNA alleles in the Malays studied were HNA-1a (0.641–0.765), -3a (0.676–0.867), -4a (0.943–1.000) and -5a (0.529–0.910). According to principal coordinate plots constructed using HNA allele frequencies, the Malay sub-ethnic groups are closely related and grouped together with other Asian populations. The risks of TRALI or neonatal neutropenia were not increased for subjects with HNA-1, -3 and -4 loci even for donor and recipient or pairs from different Malay sub-ethnic groups. Nonetheless, our estimates showed significantly higher risks of HNA alloimmunisation during pregnancy and transfusion between Malays and other genetically differentiated populations such as Africans and Europeans. Discussion This study reports HNA allele and genotype frequencies for the five Malay sub-ethnic groups living in Peninsular Malaysia for the first time. These Malay sub-ethnic groups show closer genetic relationships with other Asian populations than with Europeans and Africans. The distributions of HNA alleles in other lineages of people living in Malaysia (e.g. Chinese, Indian and Orang Asli) would be an interesting subject for future study. PMID:26057487

Uncovering Local Trends in Genetic Effects of Multiple Phenotypes via Functional Linear Models.

PubMed

Vsevolozhskaya, Olga A; Zaykin, Dmitri V; Barondess, David A; Tong, Xiaoren; Jadhav, Sneha; Lu, Qing

2016-04-01

Recent technological advances equipped researchers with capabilities that go beyond traditional genotyping of loci known to be polymorphic in a general population. Genetic sequences of study participants can now be assessed directly. This capability removed technology-driven bias toward scoring predominantly common polymorphisms and let researchers reveal a wealth of rare and sample-specific variants. Although the relative contributions of rare and common polymorphisms to trait variation are being debated, researchers are faced with the need for new statistical tools for simultaneous evaluation of all variants within a region. Several research groups demonstrated flexibility and good statistical power of the functional linear model approach. In this work we extend previous developments to allow inclusion of multiple traits and adjustment for additional covariates. Our functional approach is unique in that it provides a nuanced depiction of effects and interactions for the variables in the model by representing them as curves varying over a genetic region. We demonstrate flexibility and competitive power of our approach by contrasting its performance with commonly used statistical tools and illustrate its potential for discovery and characterization of genetic architecture of complex traits using sequencing data from the Dallas Heart Study. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

Several Different Lactase Persistence Associated Alleles and High Diversity of the Lactase Gene in the Admixed Brazilian Population

PubMed Central

Friedrich, Deise C.; Santos, Sidney E. B.; Ribeiro-dos-Santos, Ândrea K. C.; Hutz, Mara H.

2012-01-01

Adult-type hypolactasia is a common phenotype caused by the lactase enzyme deficiency. The −13910 C>T polymorphism, located 14 Kb upstream of the lactase gene (LCT) in the MCM6 gene was associated with lactase persistence (LP) in Europeans. This polymorphism is rare in Africa but several other variants associated with lactase persistence were observed in Africans. The aims of this study were to identify polymorphisms in the MCM6 region associated with the lactase persistence phenotype and to determine the distribution of LCT gene haplotypes in 981 individuals from North, Northeast and South Brazil. These polymorphisms were genotyped by PCR based methods and sequencing. The −13779*C,−13910*T, −13937*A, −14010*C, −14011*T LP alleles previously described in the MCM6 gene region that acts as an enhancer for the LCT gene were identified in Brazilians. The most common LP allele was −13910*T. Its frequency was highly correlated with European ancestry in the Brazilian populations investigated. The −13910*T was higher (0.295) in southern Brazilians of European ancestry and lower (0.175) in the Northern admixed population. LCT haplotypes were derived from the 10 LCT SNPs genotyped. Overall twenty six haplotypes previously described were identified in the four Brazilian populations studied. The Multidimensional Scaling analysis showed that Belém, in the north, was closer to Amerindians. Northeastern and southern Afro-descendants were more related with Bantu-speaking South Africans whereas the Southern population with European ancestry grouped with Southern and Northern Europeans. This study shows a high variability considering the number of LCT haplotypes observed. Due to the highly admixed nature of the Brazilian populations, the diagnosis of hypolactasia in Brazil, based only in the investigation of the −13910*T allele is an oversimplification. PMID:23029545

High-fraction brookite films from amorphous precursors.

PubMed

Haggerty, James E S; Schelhas, Laura T; Kitchaev, Daniil A; Mangum, John S; Garten, Lauren M; Sun, Wenhao; Stone, Kevin H; Perkins, John D; Toney, Michael F; Ceder, Gerbrand; Ginley, David S; Gorman, Brian P; Tate, Janet

2017-11-09

Structure-specific synthesis processes are of key importance to the growth of polymorphic functional compounds such as TiO 2 , where material properties strongly depend on structure as well as chemistry. The robust growth of the brookite polymorph of TiO 2 , a promising photocatalyst, has been difficult in both powder and thin-film forms due to the disparity of reported synthesis techniques, their highly specific nature, and lack of mechanistic understanding. In this work, we report the growth of high-fraction (~95%) brookite thin films prepared by annealing amorphous titania precursor films deposited by pulsed laser deposition. We characterize the crystallization process, eliminating the previously suggested roles of substrate templating and Na helper ions in driving brookite formation. Instead, we link phase selection directly to film thickness, offering a novel, generalizable route to brookite growth that does not rely on the presence of extraneous elements or particular lattice-matched substrates. In addition to providing a new synthesis route to brookite thin films, our results take a step towards resolving the problem of phase selection in TiO 2 growth, contributing to the further development of this promising functional material.

An oxytocin receptor polymorphism predicts amygdala reactivity and antisocial behavior in men

PubMed Central

Waller, Rebecca; Corral-Frías, Nadia S.; Vannucci, Bianca; Bogdan, Ryan; Knodt, Annchen R.; Hariri, Ahmad R.

2016-01-01

Variability in oxytocin (OXT) signaling is associated with individual differences in sex-specific social behavior across species. The effects of OXT signaling on social behavior are, in part, mediated through its modulation of amygdala function. Here, we use imaging genetics to examine sex-specific effects of three single-nucleotide polymorphisms in the human oxytocin receptor gene (OXTR; rs1042778, rs53576 and rs2254298) on threat-related amygdala reactivity and social behavior in 406 Caucasians. Analyses revealed that among men but not women, OXTR rs1042778 TT genotype was associated with increased right amygdala reactivity to angry facial expressions, which was uniquely related to higher levels of antisocial behavior among men. Moderated meditation analysis suggested a trending indirect effect of OXTR rs1042778 TT genotype on higher antisocial behavior via increased right amygdala reactivity to angry facial expressions in men. Our results provide evidence linking genetic variation in OXT signaling to individual differences in amygdala function. The results further suggest that these pathways may be uniquely important in shaping antisocial behavior in men. PMID:27036876

Sex-specific Linkage Scans in Opioid Dependence

PubMed Central

Yang, Bao-Zhu; Han, Shizhong; Kranzler, Henry R.; Palmer, Abraham A.; Gelernter, Joel

2017-01-01

Sex influences risk for opioid dependence (OD). We hypothesized that sex might interact with genetic loci that influence the risk for OD. Therefore we performed an analysis to identify sex-specific genomic susceptibility regions for OD using linkage. Over 6000 single nucleotide polymorphism (SNP) markers were genotyped for 1758 African- and European-American (AA and EA) individuals from 739 families, ascertained via affected sib-pairs with OD and/or cocaine dependence. Autosomewide non-parametric linkage scans, stratified by sex and population, were performed. We identified one significant linkage region, segregating with OD in EA men, at 71.1 cM on chromosome 4 (LOD=3.29; point-wise p=0.00005; empirical autosome-wide p=0.042), which significantly differed from the linkage signal at the same location in EA women (empirical p=0.002). Three suggestive linkage signals were identified at 181.3 cM on chromosome 7 (LOD=2.18), 104 cM on chromosome 11 (LOD=1.85), and 60.9 cM on chromosome 16 (LOD=1.93) in EA women. In AA men, four suggestive linkage signals were detected at 201.1 cM on chromosome 3 (LOD=2.32), 152.9 cM on chromosome 6 (LOD=1.86), 16.8 cM on chromosome 7 (LOD=1.95), and 36.1 cM on chromosome 17 (LOD=1.99). The significant region, mapping to 4q12-4q13.1, harbors several OD candidate genes with interconnected functionality, including VEGFR, CLOCK, PDCL2, NMU, NRSF, and IGFBP7. In conclusion, these results provide an evidence for the existence of sex-specific and population-specific differences in OD. Furthermore, these results provide positional information that will facilitate the use of targeted next-generation sequencing to search for genes that contribute to sex-specific differences in OD. PMID:27762075

Sex-specific linkage scans in opioid dependence.

PubMed

Yang, Bao-Zhu; Han, Shizhong; Kranzler, Henry R; Palmer, Abraham A; Gelernter, Joel

2017-04-01

Sex influences risk for opioid dependence (OD). We hypothesized that sex might interact with genetic loci that influence the risk for OD. Therefore we performed an analysis to identify sex-specific genomic susceptibility regions for OD using linkage. Over 6,000 single nucleotide polymorphism (SNP) markers were genotyped for 1,758 African- and European-American (AA and EA) individuals from 739 families, ascertained via affected sib-pairs with OD and/or cocaine dependence. Autosomewide non-parametric linkage scans, stratified by sex and population, were performed. We identified one significant linkage region, segregating with OD in EA men, at 71.1 cM on chromosome 4 (LOD = 3.29; point-wise P = 0.00005; empirical autosome-wide P = 0.042), which significantly differed from the linkage signal at the same location in EA women (empirical P = 0.002). Three suggestive linkage signals were identified at 181.3 cM on chromosome 7 (LOD = 2.18), 104 cM on chromosome 11 (LOD = 1.85), and 60.9 cM on chromosome 16 (LOD = 1.93) in EA women. In AA men, four suggestive linkage signals were detected at 201.1 cM on chromosome 3 (LOD = 2.32), 152.9 cM on chromosome 6 (LOD = 1.86), 16.8 cM on chromosome 7 (LOD = 1.95), and 36.1 cM on chromosome 17 (LOD = 1.99). The significant region, mapping to 4q12-4q13.1, harbors several OD candidate genes with interconnected functionality, including VEGFR, CLOCK, PDCL2, NMU, NRSF, and IGFBP7. In conclusion, these results provide an evidence for the existence of sex-specific and population-specific differences in OD. Furthermore, these results provide positional information that will facilitate the use of targeted next-generation sequencing to search for genes that contribute to sex-specific differences in OD. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Identifying tagging SNPs for African specific genetic variation from the African Diaspora Genome

PubMed Central

Johnston, Henry Richard; Hu, Yi-Juan; Gao, Jingjing; O’Connor, Timothy D.; Abecasis, Gonçalo R.; Wojcik, Genevieve L; Gignoux, Christopher R.; Gourraud, Pierre-Antoine; Lizee, Antoine; Hansen, Mark; Genuario, Rob; Bullis, Dave; Lawley, Cindy; Kenny, Eimear E.; Bustamante, Carlos; Beaty, Terri H.; Mathias, Rasika A.; Barnes, Kathleen C.; Qin, Zhaohui S.; Preethi Boorgula, Meher; Campbell, Monica; Chavan, Sameer; Ford, Jean G.; Foster, Cassandra; Gao, Li; Hansel, Nadia N.; Horowitz, Edward; Huang, Lili; Ortiz, Romina; Potee, Joseph; Rafaels, Nicholas; Ruczinski, Ingo; Scott, Alan F.; Taub, Margaret A.; Vergara, Candelaria; Levin, Albert M.; Padhukasahasram, Badri; Williams, L. Keoki; Dunston, Georgia M.; Faruque, Mezbah U.; Gietzen, Kimberly; Deshpande, Aniket; Grus, Wendy E.; Locke, Devin P.; Foreman, Marilyn G.; Avila, Pedro C.; Grammer, Leslie; Kim, Kwang-Youn A.; Kumar, Rajesh; Schleimer, Robert; De La Vega, Francisco M.; Shringarpure, Suyash S.; Musharoff, Shaila; Burchard, Esteban G.; Eng, Celeste; Hernandez, Ryan D.; Pino-Yanes, Maria; Torgerson, Dara G.; Szpiech, Zachary A.; Torres, Raul; Nicolae, Dan L.; Ober, Carole; Olopade, Christopher O; Olopade, Olufunmilayo; Oluwole, Oluwafemi; Arinola, Ganiyu; Song, Wei; Correa, Adolfo; Musani, Solomon; Wilson, James G.; Lange, Leslie A.; Akey, Joshua; Bamshad, Michael; Chong, Jessica; Fu, Wenqing; Nickerson, Deborah; Reiner, Alexander; Hartert, Tina; Ware, Lorraine B.; Bleecker, Eugene; Meyers, Deborah; Ortega, Victor E.; Maul, Pissamai; Maul, Trevor; Watson, Harold; Ilma Araujo, Maria; Riccio Oliveira, Ricardo; Caraballo, Luis; Marrugo, Javier; Martinez, Beatriz; Meza, Catherine; Ayestas, Gerardo; Francisco Herrera-Paz, Edwin; Landaverde-Torres, Pamela; Erazo, Said Omar Leiva; Martinez, Rosella; Mayorga, Alvaro; Mayorga, Luis F.; Mejia-Mejia, Delmy-Aracely; Ramos, Hector; Saenz, Allan; Varela, Gloria; Marina Vasquez, Olga; Ferguson, Trevor; Knight-Madden, Jennifer; Samms-Vaughan, Maureen; Wilks, Rainford J.; Adegnika, Akim; Ateba-Ngoa, Ulysse; Yazdanbakhsh, Maria

2017-01-01

A primary goal of The Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) is to develop an ‘African Diaspora Power Chip’ (ADPC), a genotyping array consisting of tagging SNPs, useful in comprehensively identifying African specific genetic variation. This array is designed based on the novel variation identified in 642 CAAPA samples of African ancestry with high coverage whole genome sequence data (~30× depth). This novel variation extends the pattern of variation catalogued in the 1000 Genomes and Exome Sequencing Projects to a spectrum of populations representing the wide range of West African genomic diversity. These individuals from CAAPA also comprise a large swath of the African Diaspora population and incorporate historical genetic diversity covering nearly the entire Atlantic coast of the Americas. Here we show the results of designing and producing such a microchip array. This novel array covers African specific variation far better than other commercially available arrays, and will enable better GWAS analyses for researchers with individuals of African descent in their study populations. A recent study cataloging variation in continental African populations suggests this type of African-specific genotyping array is both necessary and valuable for facilitating large-scale GWAS in populations of African ancestry. PMID:28429804

The modulatory influence of the functional COMT Val158Met polymorphism on lexical decisions and semantic priming.

PubMed

Reuter, Martin; Montag, Christian; Peters, Kristina; Kocher, Anne; Kiefer, Markus

2009-01-01

The role of the prefrontal Cortex (PFC) in higher cognitive functions - including working memory, conflict resolution, set shifting and semantic processing - has been demonstrated unequivocally. Despite the great heterogeneity among tasks measuring these phenotypes, due in part to the different cognitive sub-processes implied and the specificity of the stimulus material used, there is agreement that all of these tasks recruit an executive control system located in the PFC. On a biochemical level it is known that the dopaminergic system plays an important role in executive control functions. Evidence comes from molecular genetics relating the functional COMT Val158Met polymorphism to working memory and set shifting. In order determine whether this pattern of findings generalises to linguistic and semantic processing, we investigated the effects of the COMT Val158Met polymorphism in lexical decision making using masked and unmasked versions of the semantic priming paradigm on N = 104 healthy subjects. Although we observed strong priming effects in all conditions (masked priming, unmasked priming with short/long stimulus asynchronies (SOAs), direct and indirect priming), COMT was not significantly related to priming, suggesting no reliable influence on semantic processing. However, COMT Val158Met was strongly associated with lexical decision latencies in all priming conditions if considered separately, explaining between 9 and 14.5% of the variance. Therefore, the findings indicate that COMT mainly influences more general executive control functions in the PFC supporting the speed of lexical decisions.

Polymorphic Electronic Circuits

NASA Technical Reports Server (NTRS)

Stoica, Adrian

2004-01-01

Polymorphic electronics is a nascent technological discipline that involves, among other things, designing the same circuit to perform different analog and/or digital functions under different conditions. For example, a circuit can be designed to function as an OR gate or an AND gate, depending on the temperature (see figure). Polymorphic electronics can also be considered a subset of polytronics, which is a broader technological discipline in which optical and possibly other information- processing systems could also be designed to perform multiple functions. Polytronics is an outgrowth of evolvable hardware (EHW). The basic concepts and some specific implementations of EHW were described in a number of previous NASA Tech Briefs articles. To recapitulate: The essence of EHW is to design, construct, and test a sequence of populations of circuits that function as incrementally better solutions of a given design problem through the selective, repetitive connection and/or disconnection of capacitors, transistors, amplifiers, inverters, and/or other circuit building blocks. The evolution is guided by a search-and-optimization algorithm (in particular, a genetic algorithm) that operates in the space of possible circuits to find a circuit that exhibits an acceptably close approximation of the desired functionality. The evolved circuits can be tested by computational simulation (in which case the evolution is said to be extrinsic), tested in real hardware (in which case the evolution is said to be intrinsic), or tested in random sequences of computational simulation and real hardware (in which case the evolution is said to be mixtrinsic).

MCP1 SNPs and Pulmonary Tuberculosis in Cohorts from West Africa, the USA and Argentina: Lack of Association or Epistasis with IL12B Polymorphisms

PubMed Central

Velez Edwards, Digna R.; Tacconelli, Alessandra; Wejse, Christian; Hill, Philip C.; Morris, Gerard A. J.; Edwards, Todd L.; Gilbert, John R.; Myers, Jamie L.; Park, Yo Son; Stryjewski, Martin E.; Abbate, Eduardo; Estevan, Rosa; Rabna, Paulo; Novelli, Giuseppe; Hamilton, Carol D.; Adegbola, Richard; Østergaard, Lars; Williams, Scott M.; Scott, William K.; Sirugo, Giorgio

2012-01-01

The monocyte chemotactic protein-1 (MCP-1) is a chemokine that plays an important role in the recruitment of monocytes to M. tuberculosis infection sites, and previous studies have reported that genetic variants in MCP1 are associated with differential susceptibility to pulmonary tuberculosis (PTB). We examined eight MCP1 single nucleotide polymorphisms (SNPs) in a multi-ethnic, case-control design that included: 321 cases and 346 controls from Guinea-Bissau, 258 cases and 271 controls from The Gambia, 295 cases and 179 controls from the U.S. (African-Americans), and an additional set of 237 cases and 144 controls of European ancestry from the U.S. and Argentina. Two locus interactions were also examined for polymorphisms in MCP1 and interleukin 12B (IL12B), another gene implicated in PTB risk. Examination of previously associated MCP1 SNPs rs1024611 (−2581A/G), rs2857656 (−362G/C) and rs4586 (+900C/T) did not show evidence for association. One interaction between rs2857656 and IL12B SNP rs2288831 was observed among Africans but the effect was in the opposite direction in Guineans (OR = 1.90, p = 0.001) and Gambians (OR = 0.64, p = 0.024). Our data indicate that the effect of genetic variation within MCP1 is not clear cut and additional studies will be needed to elucidate its role in TB susceptibility. PMID:22384203

ABCG-like transporter of Trypanosoma cruzi involved in benznidazole resistance: gene polymorphisms disclose inter-strain intragenic recombination in hybrid isolates.

PubMed

Franco, Jaques; Ferreira, Renata C; Ienne, Susan; Zingales, Bianca

2015-04-01

Benznidazole (BZ) is one of the two drugs for Chagas disease treatment. In a previous study we showed that the Trypanosoma cruzi ABCG-like transporter gene, named TcABCG1, is over-expressed in parasite strains naturally resistant to BZ and that the gene of TcI BZ-resistant strains exhibited several single nucleotide polymorphisms (SNPs) as compared to the gene of CL Brener BZ-susceptible strain. Here we report the sequence of TcABCG1 gene of fourteen T. cruzi strains, with diverse degrees of BZ sensitivity and belonging to different discrete typing units (DTUs) and Tcbat group. Although DTU-specific SNPs and amino acid changes were identified, no direct correlation with BZ-resistance phenotype was found. Thus, it is plausible that the transporter abundance is a determinant factor for drug resistance, as pointed out above. Sequence data were used for Bayesian phylogenies and network genealogy analysis. The network showed a high degree of reticulation suggesting genetic exchange between the parasites. TcI and TcII clades were clearly separated. Tcbat sequences were close to TcI. A fourth clade clustered TcABCG1 haplotypes of TcV, TcVI and TcIII strains, with closer proximity to TcI. Analysis of the recombination patterns indicated that hybrid strains contain haplotypes that are mosaics most likely derived by intragenic recombination of parental sequences. The data confirm that TcII and TcIII as the parentals of TcV and TcVI DTUs. Since genetic fingerprint of TcI was found in TcIII, we sustain the previously proposed "Two Hybridization model" for the origin of hybrid strains. Among the twenty best BLASTP hits in databases, orthologues of TcABCG1 transporter were found in Leishmania spp. and African trypanosomes, though their function remains undescribed. Copyright © 2015 Elsevier B.V. All rights reserved.

[Observation on gene polymorphism of Rh blood group in Chinese Han nationality].

PubMed

Lan, Jiong-Cai; Wang, Cong-Rong; Wei, Ya-Ming; Zhou, Hua-You; Cao, Qiong; Zhang, Yin-Ze; Jiang, KuReXi; Wu, Da-Lin; Liu, Zhong

2003-12-01

To observe the gene polymorphism of Rh blood group in unrelated random individuals and families for Chinese Han nationality, polymerase chain reaction-sequence specific primer (PCR-SSP) was used to amplify the Rh C/E gene, RhD gene, exons, intron 2 and 10, insert and Rh Box in 160 blood samples of RhD positive unrelated individuals and 71 samples of RhD negative unrelated individuals and 7 samples of families whose probands were RhD-negative. The results showed that RhD genes of RhD-negative individuals with C antigens were polymorphism, three forms were found for D exon including intact, partial deletion and complete deletion exons. Insert fragments and Rh Box were found in most cases of families whose probands were RhD-negative and its inheritance accorded with the Mendel's Law, and it did not affect the expression of RhD gene. "Normal" RhD exon 4 amplifying product was not found in all of the samples. It was concluded that gene structure of the RhD-negative in Chinese was polymorphism, intact, partial deletion and complete deletion exons were found in the individuals with C antigen and probably existed specific D (nf) Ce haplotype. The function of insert was uncertain. The Rh gene sequences of Chinese Han nationality are different from those of Caucasian and the Rh gene library based on Han nationality should be established.

Prion protein testis specific (PRNT) gene polymorphisms and transcript level in ovine spermatozoa: Implications in freezability, fertilization and embryo production.

PubMed

Pereira, R M; Mesquita, P; Pires, V M R; Baptista, M C; Barbas, J P; Pimenta, J; Horta, A E M; Prates, J A M; Marques, C C

2018-07-15

An essential role of prion protein testis specific (PRNT) and prion protein 2 dublet (PRND) genes in the male reproductive function has been highlighted, although a deeper knowledge for the mechanisms involved is still lacking. Our goal was to determine the importance of the PRNT haplotypic variants and mRNA expression levels in ovine spermatozoa freezability and ability for fertilization and embryo developmental processes. Their association with the PRND gene polymorphisms was also analyzed. DNA from rams belonging to three Portuguese sheep breeds (n = 28) was screened by single-strand conformation polymorphism (SSCP) analysis to identify the PRNT and PRND polymorphisms. Semen collected from these rams was cryopreserved and fertility traits evaluated. The SSCP analyses revealed polymorphisms in the codons 6, 38, 43 and 48 of the PRNT coding region - respectively c.17C > T (p.Ser6Phe, which disrupts a consensus arginine-X-X serine/threonine motif); c.112G > C (p.Gly38 > Arg); and synonymous c.129T > C and c.144A > G. The polymorphisms in codons 6, 38 and 48 occur simultaneously while the one in codon 43 occurs independently. Six haplotypes were identified in the PRNT coding region, resulting in three different amino acid polymorphic variants (6S-38G-43C-48V, S6F-G38R-43C-48V and 6F-38R-43C-48V). The PRNT gene mRNA transcript level in spermatozoa was related to the identified haplotypic variants, either considering the codons 6-38-48 (P ≤ 0.0001) or the codon 43 alone (P ≤ 0.0001) or altogether (P ≤ 0.0001). An interaction between PRNT haplotypes and PRND genotypes on PRNT transcript level was also identified (P = 0.0003). Rams carrying the 17C-112G-144A PRNT haplotype had sperm with the highest post-thawed individual motility (P ≤ 0.03). Combined PRNT and PRND polymorphic variation influenced the post-thawed individual motility (P = 0.01). The male PRNT haplotypic, either considering the codons 6-38-48 and 43 altogether or the codon 43 alone, interfered (P ≤ 0.04) in embryo production rates. In conclusion, our data confirm that the PRNT gene is highly polymorphic in sheep and that the PRNT and PRND genotypes are associated. The identified polymorphisms of PRNT coding region seems to interfere on the ram spermatozoa mRNA transcript level and on male fertility, specifically in sperm freezability and ability for embryo development. Copyright © 2018. Published by Elsevier Inc.

Identification of new genetic polymorphisms that alter the dietary requirement for choline and vary in their distribution across ethnic and racial groups

PubMed Central

da Costa, Kerry-Ann; Corbin, Karen D.; Niculescu, Mihai D.; Galanko, Joseph A.; Zeisel, Steven H.

2014-01-01

Effect alleles (alleles with a polymorphism that is associated with the effect being measured) in a small number of single-nucleotide polymorphisms (SNPs) are known to influence the dietary requirement for choline. In this study, we examined a much larger number of SNPs (n=200) in 10 genes related to choline metabolism for associations with development of organ dysfunction (liver or muscle) when 79 humans were fed a low-choline diet. We confirmed that effect alleles in SNPs such as the C allele of PEMT rs12325817 increase the risk of developing organ dysfunction in women when they consume a diet low in choline, and we identified novel effect alleles, such as the C allele of CHKA SNP rs7928739, that alter dietary choline requirements. When fed a low-choline diet, some people presented with muscle damage rather than liver damage; several effect alleles in SLC44A1 (rs7873937, G allele; rs2771040, G; rs6479313, G; rs16924529, A; and rs3199966, C) and one in CHKB (rs1557502, A) were more common in these individuals. This suggests that pathways related to choline metabolism are more important for normal muscle function than previously thought. In European, Mexican, and Asian Americans, and in individuals of African descent, we examined the prevalence of the effect alleles in SNPs that alter choline requirement and found that they are differentially distributed among people of different ethnic and racial backgrounds. Overall, our study has identified novel genetic variants that modulate choline requirements and suggests that the dietary requirement for choline may be different across racial and ethnic groups.—Da Costa, K.-A., Corbin, K. D., Niculescu, M. D., Galanko, J. A., Zeisel, S. H. Identification of new genetic polymorphisms that alter the dietary requirement for choline and vary in their distribution across ethnic and racial groups. PMID:24671709

Investigation of Caucasian rheumatoid arthritis susceptibility loci in African patients with the same disease

PubMed Central

2012-01-01

Introduction The largest genetic risk to develop rheumatoid arthritis (RA) arises from a group of alleles of the HLA DRB1 locus ('shared epitope', SE). Over 30 non-HLA single nucleotide polymorphisms (SNPs) predisposing to disease have been identified in Caucasians, but they have never been investigated in West/Central Africa. We previously reported a lower prevalence of the SE in RA patients in Cameroon compared to European patients and aimed in the present study to investigate the contribution of Caucasian non-HLA RA SNPs to disease susceptibility in Black Africans. Methods RA cases and controls from Cameroon were genotyped for Caucasian RA susceptibility SNPs using Sequenom MassArray technology. Genotype data were also available for 5024 UK cases and 4281 UK controls and for 119 Yoruba individuals in Ibadan, Nigeria (YRI, HapMap). A Caucasian aggregate genetic-risk score (GRS) was calculated as the sum of the weighted risk-allele counts. Results After genotyping quality control procedures were performed, data on 28 Caucasian non-HLA susceptibility SNPs were available in 43 Cameroonian RA cases and 44 controls. The minor allele frequencies (MAF) were tightly correlated between Cameroonian controls and YRI individuals (correlation coefficient 93.8%, p = 1.7E-13), and they were pooled together. There was no correlation between MAF of UK and African controls; 13 markers differed by more than 20%. The MAF for markers at PTPN22, IL2RA, FCGR2A and IL2/IL21 was below 2% in Africans. The GRS showed a strong association with RA in the UK. However, the GRS did not predict RA in Africans (OR = 0.71, 95% CI 0.29 - 1.74, p = 0.456). Random sampling from the UK cohort showed that this difference in association is unlikely to be explained by small sample size or chance, but is statistically significant with p<0.001. Conclusions The MAFs of non-HLA Caucasian RA susceptibility SNPs are different between Caucasians and Africans, and several polymorphisms are barely detectable in West/Central Africa. The genetic risk of developing RA conferred by a set of 28 Caucasian susceptibility SNPs is significantly different between the UK and Africa with p<0.001. Taken together, these observations strengthen the hypothesis that the genetic architecture of RA susceptibility is different in different ethnic backgrounds. PMID:23121884

Investigation of Caucasian rheumatoid arthritis susceptibility loci in African patients with the same disease.

PubMed

Viatte, Sebastien; Flynn, Edward; Lunt, Mark; Barnes, Joanne; Singwe-Ngandeu, Madeleine; Bas, Sylvette; Barton, Anne; Gabay, Cem

2012-11-03

The largest genetic risk to develop rheumatoid arthritis (RA) arises from a group of alleles of the HLA DRB1 locus ('shared epitope', SE). Over 30 non-HLA single nucleotide polymorphisms (SNPs) predisposing to disease have been identified in Caucasians, but they have never been investigated in West/Central Africa. We previously reported a lower prevalence of the SE in RA patients in Cameroon compared to European patients and aimed in the present study to investigate the contribution of Caucasian non-HLA RA SNPs to disease susceptibility in Black Africans. RA cases and controls from Cameroon were genotyped for Caucasian RA susceptibility SNPs using Sequenom MassArray technology. Genotype data were also available for 5024 UK cases and 4281 UK controls and for 119 Yoruba individuals in Ibadan, Nigeria (YRI, HapMap). A Caucasian aggregate genetic-risk score (GRS) was calculated as the sum of the weighted risk-allele counts. After genotyping quality control procedures were performed, data on 28 Caucasian non-HLA susceptibility SNPs were available in 43 Cameroonian RA cases and 44 controls. The minor allele frequencies (MAF) were tightly correlated between Cameroonian controls and YRI individuals (correlation coefficient 93.8%, p = 1.7E-13), and they were pooled together. There was no correlation between MAF of UK and African controls; 13 markers differed by more than 20%. The MAF for markers at PTPN22, IL2RA, FCGR2A and IL2/IL21 was below 2% in Africans. The GRS showed a strong association with RA in the UK. However, the GRS did not predict RA in Africans (OR = 0.71, 95% CI 0.29 - 1.74, p = 0.456). Random sampling from the UK cohort showed that this difference in association is unlikely to be explained by small sample size or chance, but is statistically significant with p<0.001. The MAFs of non-HLA Caucasian RA susceptibility SNPs are different between Caucasians and Africans, and several polymorphisms are barely detectable in West/Central Africa. The genetic risk of developing RA conferred by a set of 28 Caucasian susceptibility SNPs is significantly different between the UK and Africa with p<0.001. Taken together, these observations strengthen the hypothesis that the genetic architecture of RA susceptibility is different in different ethnic backgrounds.

Homo sapiens-Specific Binding Site Variants within Brain Exclusive Enhancers Are Subject to Accelerated Divergence across Human Population.

PubMed

Zehra, Rabail; Abbasi, Amir Ali

2018-03-01

Empirical assessments of human accelerated noncoding DNA frgaments have delineated presence of many cis-regulatory elements. Enhancers make up an important category of such accelerated cis-regulatory elements that efficiently control the spatiotemporal expression of many developmental genes. Establishing plausible reasons for accelerated enhancer sequence divergence in Homo sapiens has been termed significant in various previously published studies. This acceleration by including closely related primates and archaic human data has the potential to open up evolutionary avenues for deducing present-day brain structure. This study relied on empirically confirmed brain exclusive enhancers to avoid any misjudgments about their regulatory status and categorized among them a subset of enhancers with an exceptionally accelerated rate of lineage specific divergence in humans. In this assorted set, 13 distinct transcription factor binding sites were located that possessed unique existence in humans. Three of 13 such sites belonging to transcription factors SOX2, RUNX1/3, and FOS/JUND possessed single nucleotide variants that made them unique to H. sapiens upon comparisons with Neandertal and Denisovan orthologous sequences. These variants modifying the binding sites in modern human lineage were further substantiated as single nucleotide polymorphisms via exploiting 1000 Genomes Project Phase3 data. Long range haplotype based tests laid out evidence of positive selection to be governing in African population on two of the modern human motif modifying alleles with strongest results for SOX2 binding site. In sum, our study acknowledges acceleration in noncoding regulatory landscape of the genome and highlights functional parts within it to have undergone accelerated divergence in present-day human population.

The impact of racial discrimination and coping strategies on internalizing symptoms in African American youth.

PubMed

Gaylord-Harden, Noni K; Cunningham, Jamila A

2009-04-01

The current study examined the impact of racial discrimination stress on internalizing symptoms and coping strategies in a sample of 268 African American early adolescents (mean age = 12.90; 56% female) from low-income communities. Information about discrimination stress, coping, and internalizing symptoms was obtained via adolescents' self-report. It was predicted that discrimination stress would be positively associated with depression and anxiety, as well as culturally-specific coping. Finally, culturally-relevant coping and mainstream coping were examined as moderators of the association between discrimination stress and internalizing symptoms. Hierarchical regression analyses indicated that discrimination stress was positively associated with depression and anxiety and predicted culturally-relevant coping while controlling for mainstream coping. Communalistic coping moderated the association between discrimination and anxiety, but demonstrated a vulnerability function by increasing anxiety at high levels of discrimination. The results highlight the salience of racial discrimination for African American adolescents and the importance of considering culturally-specific coping behaviors.

Insulin Transactivator MafA Regulates Intrathymic Expression of Insulin and Affects Susceptibility to Type 1 Diabetes

PubMed Central

Noso, Shinsuke; Kataoka, Kohsuke; Kawabata, Yumiko; Babaya, Naru; Hiromine, Yoshihisa; Yamaji, Kaori; Fujisawa, Tomomi; Aramata, Shinsaku; Kudo, Takashi; Takahashi, Satoru; Ikegami, Hiroshi

2010-01-01

OBJECTIVE Tissue-specific self-antigens are ectopically expressed within the thymus and play an important role in the induction of central tolerance. Insulin is expressed in both pancreatic islets and the thymus and is considered to be the primary antigen for type 1 diabetes. Here, we report the role of the insulin transactivator MafA in the expression of insulin in the thymus and susceptibility to type 1 diabetes. RESEARCH DESIGN AND METHODS The expression profiles of transcriptional factors (Pdx1, NeuroD, Mafa, and Aire) in pancreatic islets and the thymus were examined in nonobese diabetic (NOD) and control mice. Thymic Ins2 expression and serum autoantibodies were examined in Mafa knockout mice. Luciferase reporter assay was performed for newly identified polymorphisms of mouse Mafa and human MAFA. A case-control study was applied for human MAFA polymorphisms. RESULTS Mafa, Ins2, and Aire expression was detected in the thymus. Mafa expression was lower in NOD thymus than in the control and was correlated with Ins2 expression. Targeted disruption of MafA reduced thymic Ins2 expression and induced autoantibodies against pancreatic islets. Functional polymorphisms of MafA were newly identified in NOD mice and humans, and polymorphisms of human MAFA were associated with susceptibility to type 1 diabetes but not to autoimmune thyroid disease. CONCLUSIONS These data indicate that functional polymorphisms of MafA are associated with reduced expression of insulin in the thymus and susceptibility to type 1 diabetes in the NOD mouse as well as human type 1 diabetes. PMID:20682694

MIF functional polymorphisms (-794 CATT5-8 and -173 G>C) are associated with MIF serum levels, severity and progression in male multiple sclerosis from western Mexican population.

PubMed

Castañeda-Moreno, V A; De la Cruz-Mosso, U; Torres-Carrillo, N; Macías-Islas, M A; Padilla-De la Torre, O; Mireles-Ramírez, M A; González-Pérez, O; Ruiz-Sandoval, J L; Huerta, M; Trujillo, X; Ortuño-Sahagún, D; Muñoz-Valle, J F

2018-07-15

Macrophage migration inhibitory factor (MIF) is a cytokine associated with tissue damage in multiple autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis. The role of MIF in multiple sclerosis (MS) and the contribution of its polymorphisms are unknown in our population. Therefore, we decided to investigate the genetic association of -794 CATT 5-8 (rs5844572) and -173 G>C (rs755622) MIF polymorphisms with MS, clinical variables and MIF serum levels in the population of western Mexico. 230 MS patients diagnosed according to McDonald criteria and 248 control subjects (CS) were recruited for this study, both polymorphisms were genotyped by PCR and PCR-RFLP and MIF serum levels were measured by ELISA kit. Severity and progression of MS were evaluated by EDSS and MSSS scores, respectively. Genotypes carrying the 5 repeats alleles of -794 CATT 5-8 MIF polymorphism present higher MIF serum levels in comparison with no carriers, and the presence of 5,7 heterozygous genotype contribute to the increase of disease severity and damage progression in MS patients. Notably when we stratified by sex, an effect of risk alleles (7 repeats and -173*C) of both MIF polymorphisms on EDSS and MSSS scores on males was found (p < 0.01). This study suggests that polymorphic alleles of MIF polymorphisms could act as sex-specific disease modifiers that increase the severity and progression of MS in male Mexican-Mestizo western population. Copyright © 2018 Elsevier B.V. All rights reserved.

Association study between GSTT1 and GSTM1 polymorphisms and risk of preeclampsia in Chinese population.

PubMed

Guan, Linbo; Fan, Ping; Liu, Xinghui; Liu, Rui; Chen, Yihong; Ye, Liyan; Chen, Jinxin; Zhu, Yue; Liu, Yu; Bai, Huai

2016-09-01

Preeclampsia is a pregnancy-specific disorder associated with oxidative stress. The glutathione S-transferases (GST) are a group of enzymes that protect cells from oxidative stress. Functional genetic polymorphisms of GST genes (GSTT1, GSTM1) have previously been reported. The aim of this study was to investigate the association of GST gene polymorphisms with the risk of preeclampsia in Chinese subjects. The case-control population consists of 525 subjects. The genotyping of the GSTT1 and GSTM1 polymorphisms was carried out on genomic DNA using the multiplex polymerase chain reaction (PCR). We calculated odds ratios (ORs), adjusted for the confounding variables, to estimate the association between gene polymorphisms and preeclampsia. The GSTT1 null genotype was found to be protective from the development of preeclampsia (odds ratios 0.645, 95% confidence interval 0.421-0.989; P=0.044). Further analysis showed that a combination of deletion genotypes of the GSTT1 and GSTM1 genes conferred an even lower risk of preeclampsia (OR=0.470, 95%CI=0.255-0.866; P=0.015). There is no relationship between the GSTT1 and GSTM1 gene polymorphisms and blood pressure levels in pregnant women with and without preeclampsia. Our data suggest that a GSTT1 null polymorphism might be associated with decreased risk for preeclampsia in the Chinese population, and that this risk decreases with the combination of both GSTT1 and GSTM1 null polymorphisms. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Construction of a high-density genetic map by specific locus amplified fragment sequencing (SLAF-seq) and its application to Quantitative Trait Loci (QTL) analysis for boll weight in upland cotton (Gossypium hirsutum.).

PubMed

Zhang, Zhen; Shang, Haihong; Shi, Yuzhen; Huang, Long; Li, Junwen; Ge, Qun; Gong, Juwu; Liu, Aiying; Chen, Tingting; Wang, Dan; Wang, Yanling; Palanga, Koffi Kibalou; Muhammad, Jamshed; Li, Weijie; Lu, Quanwei; Deng, Xiaoying; Tan, Yunna; Song, Weiwu; Cai, Juan; Li, Pengtao; Rashid, Harun or; Gong, Wankui; Yuan, Youlu

2016-04-11

Upland Cotton (Gossypium hirsutum) is one of the most important worldwide crops it provides natural high-quality fiber for the industrial production and everyday use. Next-generation sequencing is a powerful method to identify single nucleotide polymorphism markers on a large scale for the construction of a high-density genetic map for quantitative trait loci mapping. In this research, a recombinant inbred lines population developed from two upland cotton cultivars 0-153 and sGK9708 was used to construct a high-density genetic map through the specific locus amplified fragment sequencing method. The high-density genetic map harbored 5521 single nucleotide polymorphism markers which covered a total distance of 3259.37 cM with an average marker interval of 0.78 cM without gaps larger than 10 cM. In total 18 quantitative trait loci of boll weight were identified as stable quantitative trait loci and were detected in at least three out of 11 environments and explained 4.15-16.70 % of the observed phenotypic variation. In total, 344 candidate genes were identified within the confidence intervals of these stable quantitative trait loci based on the cotton genome sequence. These genes were categorized based on their function through gene ontology analysis, Kyoto Encyclopedia of Genes and Genomes analysis and eukaryotic orthologous groups analysis. This research reported the first high-density genetic map for Upland Cotton (Gossypium hirsutum) with a recombinant inbred line population using single nucleotide polymorphism markers developed by specific locus amplified fragment sequencing. We also identified quantitative trait loci of boll weight across 11 environments and identified candidate genes within the quantitative trait loci confidence intervals. The results of this research would provide useful information for the next-step work including fine mapping, gene functional analysis, pyramiding breeding of functional genes as well as marker-assisted selection.

Polymorphisms in the microglial marker molecule CX3CR1 affect the blood volume of the human brain.

PubMed

Sakai, Mai; Takeuchi, Hikaru; Yu, Zhiqian; Kikuchi, Yoshie; Ono, Chiaki; Takahashi, Yuta; Ito, Fumiaki; Matsuoka, Hiroo; Tanabe, Osamu; Yasuda, Jun; Taki, Yasuyuki; Kawashima, Ryuta; Tomita, Hiroaki

2018-06-01

CX3CR1, a G-protein-coupled receptor, is involved in various inflammatory processes. Two non-synonymous single nucleotide polymorphisms, V249I (rs3732379) and T280M (rs3732378), are located in the sixth and seventh transmembrane domains of the CX3CR1 protein, respectively. Previous studies have indicated significant associations between T280M and leukocyte functional characteristics, including adhesion, signaling, and chemotaxis, while the function of V249I is unclear. In the brain, microglia are the only proven and widely accepted CX3CR1-expressing cells. This study aimed to specify whether there were specific brain regions on which these two single nucleotide polymorphisms exert their biological impacts through their functional effects on microglia. Associations between the single nucleotide polymorphisms and brain characteristics, including gray and white matter volumes, white matter integrity, resting arterial blood volume, and cerebral blood flow, were evaluated among 1300 healthy Japanese individuals. The major allele carriers (V249 and T280) were significantly associated with an increased total arterial blood volume of the whole brain, especially around the bilateral precuneus, left posterior cingulate cortex, and left posterior parietal cortex. There were no significant associations between the genotypes and other brain structural indicators. This finding suggests that the CX3CR1 variants may affect arterial structures in the brain, possibly via interactions between microglia and brain microvascular endothelial cells. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

Polymorphisms of glutathione peroxidase 1 (GPX1 Pro198Leu) and catalase (CAT C-262T) in women with spontaneous abortion.

PubMed

Sabet, Eliza Eskafi; Salehi, Zivar; Khodayari, Siamak; Zarafshan, Samin Sabouhi; Zahiri, Ziba

2014-10-01

About 10%-15% of conceptions are lost spontaneously prior to 20 weeks. Apart from the clinical problems, genetic variations have also been proposed as a susceptibility factor to miscarriage. Glutathione peroxidase 1 (GPX1) and catalase (CAT) encode two antioxidant enzymes that detoxify H2O2 and protect the cells from oxidative damage. A functional polymorphism at codon 198 of the GPX1 gene causes a C/T substitution in exon 2, which encodes for either proline or leucine (Pro198Leu). The CAT gene has a polymorphic site in the promoter region at position -262 (C-262T) which alters the expression and enzyme blood levels, leading to some pathological clinical conditions. In this study, we evaluated the association of these two polymorphisms with the risk of spontaneous abortion. Genomic DNA from 105 cases with spontaneous abortion and 90 healthy women were genotyped using allele-specific PCR (AS-PCR) and polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP). The genetic distributions for GPX1 did not differ significantly between cases and controls (p = 0.680). However, C-262T polymorphism was significantly associated with the risk of the disease (OR, 5.50; 95% CI, 1.43-21.09; p = 0.012). In conclusion, this study indicates that CAT -262T/T genotype confers less susceptibility to spontaneous abortion, while GPX1 Pro198Leu polymorphism may not be correlated with the disease.

A second generation human haplotype map of over 3.1 million SNPs.

PubMed

Frazer, Kelly A; Ballinger, Dennis G; Cox, David R; Hinds, David A; Stuve, Laura L; Gibbs, Richard A; Belmont, John W; Boudreau, Andrew; Hardenbol, Paul; Leal, Suzanne M; Pasternak, Shiran; Wheeler, David A; Willis, Thomas D; Yu, Fuli; Yang, Huanming; Zeng, Changqing; Gao, Yang; Hu, Haoran; Hu, Weitao; Li, Chaohua; Lin, Wei; Liu, Siqi; Pan, Hao; Tang, Xiaoli; Wang, Jian; Wang, Wei; Yu, Jun; Zhang, Bo; Zhang, Qingrun; Zhao, Hongbin; Zhao, Hui; Zhou, Jun; Gabriel, Stacey B; Barry, Rachel; Blumenstiel, Brendan; Camargo, Amy; Defelice, Matthew; Faggart, Maura; Goyette, Mary; Gupta, Supriya; Moore, Jamie; Nguyen, Huy; Onofrio, Robert C; Parkin, Melissa; Roy, Jessica; Stahl, Erich; Winchester, Ellen; Ziaugra, Liuda; Altshuler, David; Shen, Yan; Yao, Zhijian; Huang, Wei; Chu, Xun; He, Yungang; Jin, Li; Liu, Yangfan; Shen, Yayun; Sun, Weiwei; Wang, Haifeng; Wang, Yi; Wang, Ying; Xiong, Xiaoyan; Xu, Liang; Waye, Mary M Y; Tsui, Stephen K W; Xue, Hong; Wong, J Tze-Fei; Galver, Luana M; Fan, Jian-Bing; Gunderson, Kevin; Murray, Sarah S; Oliphant, Arnold R; Chee, Mark S; Montpetit, Alexandre; Chagnon, Fanny; Ferretti, Vincent; Leboeuf, Martin; Olivier, Jean-François; Phillips, Michael S; Roumy, Stéphanie; Sallée, Clémentine; Verner, Andrei; Hudson, Thomas J; Kwok, Pui-Yan; Cai, Dongmei; Koboldt, Daniel C; Miller, Raymond D; Pawlikowska, Ludmila; Taillon-Miller, Patricia; Xiao, Ming; Tsui, Lap-Chee; Mak, William; Song, You Qiang; Tam, Paul K H; Nakamura, Yusuke; Kawaguchi, Takahisa; Kitamoto, Takuya; Morizono, Takashi; Nagashima, Atsushi; Ohnishi, Yozo; Sekine, Akihiro; Tanaka, Toshihiro; Tsunoda, Tatsuhiko; Deloukas, Panos; Bird, Christine P; Delgado, Marcos; Dermitzakis, Emmanouil T; Gwilliam, Rhian; Hunt, Sarah; Morrison, Jonathan; Powell, Don; Stranger, Barbara E; Whittaker, Pamela; Bentley, David R; Daly, Mark J; de Bakker, Paul I W; Barrett, Jeff; Chretien, Yves R; Maller, Julian; McCarroll, Steve; Patterson, Nick; Pe'er, Itsik; Price, Alkes; Purcell, Shaun; Richter, Daniel J; Sabeti, Pardis; Saxena, Richa; Schaffner, Stephen F; Sham, Pak C; Varilly, Patrick; Altshuler, David; Stein, Lincoln D; Krishnan, Lalitha; Smith, Albert Vernon; Tello-Ruiz, Marcela K; Thorisson, Gudmundur A; Chakravarti, Aravinda; Chen, Peter E; Cutler, David J; Kashuk, Carl S; Lin, Shin; Abecasis, Gonçalo R; Guan, Weihua; Li, Yun; Munro, Heather M; Qin, Zhaohui Steve; Thomas, Daryl J; McVean, Gilean; Auton, Adam; Bottolo, Leonardo; Cardin, Niall; Eyheramendy, Susana; Freeman, Colin; Marchini, Jonathan; Myers, Simon; Spencer, Chris; Stephens, Matthew; Donnelly, Peter; Cardon, Lon R; Clarke, Geraldine; Evans, David M; Morris, Andrew P; Weir, Bruce S; Tsunoda, Tatsuhiko; Mullikin, James C; Sherry, Stephen T; Feolo, Michael; Skol, Andrew; Zhang, Houcan; Zeng, Changqing; Zhao, Hui; Matsuda, Ichiro; Fukushima, Yoshimitsu; Macer, Darryl R; Suda, Eiko; Rotimi, Charles N; Adebamowo, Clement A; Ajayi, Ike; Aniagwu, Toyin; Marshall, Patricia A; Nkwodimmah, Chibuzor; Royal, Charmaine D M; Leppert, Mark F; Dixon, Missy; Peiffer, Andy; Qiu, Renzong; Kent, Alastair; Kato, Kazuto; Niikawa, Norio; Adewole, Isaac F; Knoppers, Bartha M; Foster, Morris W; Clayton, Ellen Wright; Watkin, Jessica; Gibbs, Richard A; Belmont, John W; Muzny, Donna; Nazareth, Lynne; Sodergren, Erica; Weinstock, George M; Wheeler, David A; Yakub, Imtaz; Gabriel, Stacey B; Onofrio, Robert C; Richter, Daniel J; Ziaugra, Liuda; Birren, Bruce W; Daly, Mark J; Altshuler, David; Wilson, Richard K; Fulton, Lucinda L; Rogers, Jane; Burton, John; Carter, Nigel P; Clee, Christopher M; Griffiths, Mark; Jones, Matthew C; McLay, Kirsten; Plumb, Robert W; Ross, Mark T; Sims, Sarah K; Willey, David L; Chen, Zhu; Han, Hua; Kang, Le; Godbout, Martin; Wallenburg, John C; L'Archevêque, Paul; Bellemare, Guy; Saeki, Koji; Wang, Hongguang; An, Daochang; Fu, Hongbo; Li, Qing; Wang, Zhen; Wang, Renwu; Holden, Arthur L; Brooks, Lisa D; McEwen, Jean E; Guyer, Mark S; Wang, Vivian Ota; Peterson, Jane L; Shi, Michael; Spiegel, Jack; Sung, Lawrence M; Zacharia, Lynn F; Collins, Francis S; Kennedy, Karen; Jamieson, Ruth; Stewart, John

2007-10-18

We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations.

NFE2L2 pathway polymorphisms and lung function decline in chronic obstructive pulmonary disease

PubMed Central

Malhotra, Deepti; Boezen, H. Marike; Siedlinski, Mateusz; Postma, Dirkje S.; Wong, Vivien; Akhabir, Loubna; He, Jian-Qing; Connett, John E.; Anthonisen, Nicholas R.; Paré, Peter D.; Biswal, Shyam

2012-01-01

An oxidant-antioxidant imbalance in the lung contributes to the development of chronic obstructive pulmonary disease (COPD) that is caused by a complex interaction of genetic and environmental risk factors. Nuclear erythroid 2-related factor 2 (NFE2L2 or NRF2) is a critical molecule in the lung's defense mechanism against oxidants. We investigated whether polymorphisms in the NFE2L2 pathway affected the rate of decline of lung function in smokers from the Lung Health Study (LHS)(n = 547) and in a replication set, the Vlagtwedde-Vlaardingen cohort (n = 533). We selected polymorphisms in NFE2L2 in genes that positively or negatively regulate NFE2L2 transcriptional activity and in genes that are regulated by NFE2L2. Polymorphisms in 11 genes were significantly associated with rate of lung function decline in the LHS. One of these polymorphisms, rs11085735 in the KEAP1 gene, was previously shown to be associated with the level of lung function in the Vlagtwedde-Vlaardingen cohort but not with decline of lung function. Of the 23 associated polymorphisms in the LHS, only rs634534 in the FOSL1 gene showed a significant association in the Vlagtwedde-Vlaardingen cohort with rate of lung function decline, but the direction of the association was not consistent with that in the LHS. In summary, despite finding several nominally significant polymorphisms in the LHS, none of these associations were replicated in the Vlagtwedde-Vlaardingen cohort, indicating lack of effect of polymorphisms in the NFE2L2 pathway on the rate of decline of lung function. PMID:22693272

NFE2L2 pathway polymorphisms and lung function decline in chronic obstructive pulmonary disease.

PubMed

Sandford, Andrew J; Malhotra, Deepti; Boezen, H Marike; Siedlinski, Mateusz; Postma, Dirkje S; Wong, Vivien; Akhabir, Loubna; He, Jian-Qing; Connett, John E; Anthonisen, Nicholas R; Paré, Peter D; Biswal, Shyam

2012-08-01

An oxidant-antioxidant imbalance in the lung contributes to the development of chronic obstructive pulmonary disease (COPD) that is caused by a complex interaction of genetic and environmental risk factors. Nuclear erythroid 2-related factor 2 (NFE2L2 or NRF2) is a critical molecule in the lung's defense mechanism against oxidants. We investigated whether polymorphisms in the NFE2L2 pathway affected the rate of decline of lung function in smokers from the Lung Health Study (LHS)(n = 547) and in a replication set, the Vlagtwedde-Vlaardingen cohort (n = 533). We selected polymorphisms in NFE2L2 in genes that positively or negatively regulate NFE2L2 transcriptional activity and in genes that are regulated by NFE2L2. Polymorphisms in 11 genes were significantly associated with rate of lung function decline in the LHS. One of these polymorphisms, rs11085735 in the KEAP1 gene, was previously shown to be associated with the level of lung function in the Vlagtwedde-Vlaardingen cohort but not with decline of lung function. Of the 23 associated polymorphisms in the LHS, only rs634534 in the FOSL1 gene showed a significant association in the Vlagtwedde-Vlaardingen cohort with rate of lung function decline, but the direction of the association was not consistent with that in the LHS. In summary, despite finding several nominally significant polymorphisms in the LHS, none of these associations were replicated in the Vlagtwedde-Vlaardingen cohort, indicating lack of effect of polymorphisms in the NFE2L2 pathway on the rate of decline of lung function.

HLA-E coding and 3' untranslated region variability determined by next-generation sequencing in two West-African population samples.

PubMed

Castelli, Erick C; Mendes-Junior, Celso T; Sabbagh, Audrey; Porto, Iane O P; Garcia, André; Ramalho, Jaqueline; Lima, Thálitta H A; Massaro, Juliana D; Dias, Fabrício C; Collares, Cristhianna V A; Jamonneau, Vincent; Bucheton, Bruno; Camara, Mamadou; Donadi, Eduardo A

2015-12-01

HLA-E is a non-classical Human Leucocyte Antigen class I gene with immunomodulatory properties. Whereas HLA-E expression usually occurs at low levels, it is widely distributed amongst human tissues, has the ability to bind self and non-self antigens and to interact with NK cells and T lymphocytes, being important for immunosurveillance and also for fighting against infections. HLA-E is usually the most conserved locus among all class I genes. However, most of the previous studies evaluating HLA-E variability sequenced only a few exons or genotyped known polymorphisms. Here we report a strategy to evaluate HLA-E variability by next-generation sequencing (NGS) that might be used to other HLA loci and present the HLA-E haplotype diversity considering the segment encoding the entire HLA-E mRNA (including 5'UTR, introns and the 3'UTR) in two African population samples, Susu from Guinea-Conakry and Lobi from Burkina Faso. Our results indicate that (a) the HLA-E gene is indeed conserved, encoding mainly two different protein molecules; (b) Africans do present several unknown HLA-E alleles presenting synonymous mutations; (c) the HLA-E 3'UTR is quite polymorphic and (d) haplotypes in the HLA-E 3'UTR are in close association with HLA-E coding alleles. NGS has proved to be an important tool on data generation for future studies evaluating variability in non-classical MHC genes. Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

A Worldwide Map of Plasmodium falciparum K13-Propeller Polymorphisms

PubMed Central

Ménard, D.; Khim, N.; Beghain, J.; Adegnika, A.A.; Shafiul-Alam, M.; Amodu, O.; Rahim-Awab, G.; Barnadas, C.; Berry, A.; Boum, Y.; Bustos, M.D.; Cao, J.; Chen, J.-H.; Collet, L.; Cui, L.; Thakur, G.-D.; Dieye, A.; Djallé, D.; Dorkenoo, M.A.; Eboumbou-Moukoko, C.E.; Espino, F.-E.-C.J.; Fandeur, T.; Ferreira-da-Cruz, M.-F.; Fola, A.A.; Fuehrer, H.-P.; Hassan, A.M.; Herrera, S.; Hongvanthong, B.; Houzé, S.; Ibrahim, M.L.; Jahirul-Karim, M.; Jiang, L.; Kano, S.; Ali-Khan, W.; Khanthavong, M.; Kremsner, P.G.; Lacerda, M.; Leang, R.; Leelawong, M.; Li, M.; Lin, K.; Mazarati, J.-B.; Ménard, S.; Morlais, I.; Muhindo-Mavoko, H.; Musset, L.; Na-Bangchang, K.; Nambozi, M.; Niaré, K.; Noedl, H.; Ouédraogo, J.-B.; Pillai, D.R.; Pradines, B.; Quang-Phuc, B.; Ramharter, M.; Randrianarivelojosia, M.; Sattabongkot, J.; Sheikh-Omar, A.; Silué, K.D.; Sirima, S.B.; Sutherland, C.; Syafruddin, D.; Tahar, R.; Tang, L.-H.; Touré, O.A.; Tshibangu-wa-Tshibangu, P.; Vigan-Womas, I.; Warsame, M.; Wini, L.; Zakeri, S.; Kim, S.; Eam, R.; Berne, L.; Khean, C.; Chy, S.; Ken, M.; Loch, K.; Canier, L.; Duru, V.; Legrand, E.; Barale, J.-C.; Stokes, B.; Straimer, J.; Witkowski, B.; Fidock, D.A.; Rogier, C.; Ringwald, P.; Ariey, F.; Mercereau-Puijalon, O.

2016-01-01

BACKGROUND Recent gains in reducing the global burden of malaria are threatened by the emergence of Plasmodium falciparum resistance to artemisinins. The discovery that mutations in portions of a P. falciparum gene encoding kelch (K13)–propeller domains are the major determinant of resistance has provided opportunities for monitoring such resistance on a global scale. METHODS We analyzed the K13-propeller sequence polymorphism in 14,037 samples collected in 59 countries in which malaria is endemic. Most of the samples (84.5%) were obtained from patients who were treated at sentinel sites used for nationwide surveillance of antimalarial resistance. We evaluated the emergence and dissemination of mutations by haplotyping neighboring loci. RESULTS We identified 108 nonsynonymous K13 mutations, which showed marked geographic disparity in their frequency and distribution. In Asia, 36.5% of the K13 mutations were distributed within two areas — one in Cambodia, Vietnam, and Laos and the other in western Thailand, Myanmar, and China — with no overlap. In Africa, we observed a broad array of rare nonsynonymous mutations that were not associated with delayed parasite clearance. The gene-edited Dd2 transgenic line with the A578S mutation, which expresses the most frequently observed African allele, was found to be susceptible to artemisinin in vitro on a ring-stage survival assay. CONCLUSIONS No evidence of artemisinin resistance was found outside Southeast Asia and China, where resistance-associated K13 mutations were confined. The common African A578S allele was not associated with clinical or in vitro resistance to artemisinin, and many African mutations appear to be neutral. PMID:27332904

Investigation of the estrogen receptor-alpha gene with type 2 diabetes and/or nephropathy in African-American and European-American populations.

PubMed

Gallagher, Carla J; Keene, Keith L; Mychaleckyj, Josyf C; Langefeld, Carl D; Hirschhorn, Joel N; Henderson, Brian E; Gordon, Candace J; Freedman, Barry I; Rich, Stephen S; Bowden, Donald W; Sale, Michèle M

2007-03-01

The estrogen receptor-alpha gene (ESR1) was selected as a positional candidate under a type 2 diabetes linkage peak at 6q24-27. A total of 42 ESR1 single nucleotide polymorphisms (SNPs) were genotyped in 380 African-American type 2 diabetic case subjects with end-stage renal disease (ESRD) and 276 African-American control subjects. A total of 22 ancestry informative markers were also genotyped, and the program Admixmap was used to adjust allelic and haplotypic association tests for individual estimates of admixture. The most significant association with type 2 diabetes-ESRD was with rs1033182 in intron 2 (P = 0.013, admixture-adjusted P(a) = 0.021). Genotyping 17 SNPs across a region of ESR1 intron 1-intron 2 in an expanded population of 851 case and 635 control subjects supported association with rs1033182 (P = 0.004, P(a) = 0.027) and with an independent six-SNP haplotype of high linkage disequilibrium spanning 6.4 kb (P < 0.0001, P(a) < 0.0001). The same 17 ESR1 SNPs were genotyped in 300 European-American type 2 diabetes-ESRD case subjects and 310 European-American control subjects. Two intron 2 SNPs, rs2431260 (P = 0.015) and rs1709183 (P = 0.019), and a four-SNP haplotype containing these SNPs (P = 0.033) were associated with type 2 diabetes and/or ESRD. Results suggest that intron 1 and intron 2 of the ESR1 gene may contain functionally important regions related to type 2 diabetes or ESRD risk.

Polymorphic Alu insertions among Mayan populations.

PubMed

Herrera, R J; Rojas, D P; Terreros, M C

2007-01-01

The Mayan homeland within Mesoamerica spans five countries: Belize, El Salvador, Guatemala, Honduras and Mexico. There are indications that the people we call the Maya migrated from the north to the highlands of Guatemala as early as 4000 B.C. Their existence was village-based and agricultural. The culture of these Preclassic Mayans owes much to the earlier Olmec civilization, which flourished in the southern portion of North America. In this study, four different Mayan groups were examined to assess their genetic variability. Ten polymorphic Alu insertion (PAI) loci were employed to ascertain the genetic affinities among these Mayan groups. North American, African, European and Asian populations were also examined as reference populations. Our results suggest that the Mayan groups examined in this study are not genetically homogeneous.

Interleukin gene polymorphisms and breast cancer: a case control study and systematic literature review

PubMed Central

Balasubramanian, SP; Azmy, IAF; Higham, SE; Wilson, AG; Cross, SS; Cox, A; Brown, NJ; Reed, MW

2006-01-01

Background Interleukins and cytokines play an important role in the pathogenesis of many solid cancers. Several single nucleotide polymorphisms (SNPs) identified in cytokine genes are thought to influence the expression or function of these proteins and many have been evaluated for their role in inflammatory disease and cancer predisposition. The aim of this study was to evaluate any role of specific SNPs in the interleukin genes IL1A, IL1B, IL1RN, IL4R, IL6 and IL10 in predisposition to breast cancer susceptibility and severity. Methods Candidate single nucleotide polymorphisms (SNPs) in key cytokine genes were genotyped in breast cancer patients and in appropriate healthy volunteers who were similar in age, race and sex. Genotyping was performed using a high throughput allelic discrimination method. Data on clinico-pathological details and survival were collected. A systematic review of Medline English literature was done to retrieve previous studies of these polymorphisms in breast cancer. Results None of the polymorphisms studied showed any overall predisposition to breast cancer susceptibility, severity or to time to death or occurrence of distant metastases. The results of the systematic review are summarised. Conclusion Polymorphisms within key interleukin genes (IL1A, IL1B, IL1RN, IL4R, IL6 and IL10 do not appear to play a significant overall role in breast cancer susceptibility or severity. PMID:16842617

RSRC1 and CPZ gene polymorphisms with neuroblastoma susceptibility in Chinese children.

PubMed

Tang, Jue; Liu, Wei; Zhu, Jinhong; Zhang, Jiao; Wang, Feng-Hua; Liang, Jiang-Hua; Zeng, Jia-Hang; Wang, Hui; Xia, Huimin; He, Jing

2018-07-01

Two new neuroblastoma susceptibility loci at 3q25 (RSRC1 rs6441201 G > A) and 4p16 (CPZ rs3796725 T > C and rs3796727 A > G) were identified by a genome-wide association study (GWAS) involving Italians, African Americans and European Americans. In this case-control study with 393 neuroblastoma cases and 812 controls, we investigated the association between these three polymorphisms and neuroblastoma susceptibility in Chinese population. We found that participants harboring the RSRC1 rs6441201A allele were associated with an increased risk of neuroblastoma (AA vs. GG: adjusted OR = 1.55, 95% CI = 1.03-2.34, P = 0.036). No significant association between the CPZ polymorphisms (rs3796725 T > C and rs3796727A > G) and neuroblastoma susceptibility was observed. In conclusion, our results confirm that the RSRC1 rs6441201A allele is associated with neuroblastoma susceptibility in Chinese population. Copyright © 2018 Elsevier B.V. All rights reserved.

Methylenetetrahydrofolate reductase C677T polymorphism is associated with increased risk of coronary artery disease in young South African Indians.

PubMed

Ramkaran, Prithiksha; Phulukdaree, Alisa; Khan, Sajidah; Moodley, Devapregasan; Chuturgoon, Anil A

2015-10-15

Methylenetetrahydrofolate reductase (MTHFR) reduces 5',10'-methylenetetrahydrofolate to 5'-methyltetrahydrofolate, and is involved in remethylation of homocysteine to methionine, two important reactions involved in folate metabolism and methylation pathways. The common MTHFR C677T single nucleotide polymorphism (SNP) (rs1801133) has been associated with raised levels of homocysteine, a well known risk factor for coronary artery disease (CAD). CAD is a major cause of mortality worldwide. The age of onset of this chronic disorder is on the decline, particularly in the Indian population. Indians in South Africa (SA) have a higher prevalence of premature CAD compared to Black South Africans. The MTHFR C677T SNP has not been investigated in the SA Indian population. The present study therefore investigated the MTHFR C677T SNP in young SA Indian males with CAD compared to young Indian and Black male controls. A total of 290 subjects were recruited into this study which included 106 CAD patients (diagnosed on angiography, mean age 37.5, range 24-45 years), 100 Indian male controls (mean age 37.5, range 28-45 years), and 84 Black male controls (mean age 36.4, range 25-45). Polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) was used to genotype CAD patients and healthy controls. Data for clinical markers were obtained from pathology reports. There was a significant association between the 677 MTHFR variant (T) allele and CAD patients compared to the healthy Indian controls (p=0.0353, OR=2.105 95% CI 1.077-4.114). Indian controls presented with a higher frequency of the variant allele compared to Black controls (7% vs. 2% respectively, p=0.0515 OR=3.086 95% CI 0.9958-9.564). The MTHFR C677T SNP did not influence levels of total cholesterol, LDL, HDL, triglycerides, fasting glucose, fasting insulin, HbA1c or hsCRP. The higher frequency of the MTHFR 677 variant allele in South African Indians may be a contributing factor to the higher risk profile for the development of premature CAD in Indians. Copyright © 2015 Elsevier B.V. All rights reserved.

Integrative genomic analysis identifies ancestry-related expression quantitative trait loci on DNA polymerase β and supports the association of genetic ancestry with survival disparities in head and neck squamous cell carcinoma.

PubMed

Ramakodi, Meganathan P; Devarajan, Karthik; Blackman, Elizabeth; Gibbs, Denise; Luce, Danièle; Deloumeaux, Jacqueline; Duflo, Suzy; Liu, Jeffrey C; Mehra, Ranee; Kulathinal, Rob J; Ragin, Camille C

2017-03-01

African Americans with head and neck squamous cell carcinoma (HNSCC) have a lower survival rate than whites. This study investigated the functional importance of ancestry-informative single-nucleotide polymorphisms (SNPs) in HNSCC and also examined the effect of functionally important genetic elements on racial disparities in HNSCC survival. Ancestry-informative SNPs, RNA sequencing, methylation, and copy number variation data for 316 oral cavity and laryngeal cancer patients were analyzed across 178 DNA repair genes. The results of expression quantitative trait locus (eQTL) analyses were also replicated with a Gene Expression Omnibus (GEO) data set. The effects of eQTLs on overall survival (OS) and disease-free survival (DFS) were evaluated. Five ancestry-related SNPs were identified as cis-eQTLs in the DNA polymerase β (POLB) gene (false discovery rate [FDR] < 0.01). The homozygous/heterozygous genotypes containing the African allele showed higher POLB expression than the homozygous white allele genotype (P < .001). A replication study using a GEO data set validated all 5 eQTLs and also showed a statistically significant difference in POLB expression based on genetic ancestry (P = .002). An association was observed between these eQTLs and OS (P < .037; FDR < 0.0363) as well as DFS (P = .018 to .0629; FDR < 0.079) for oral cavity and laryngeal cancer patients treated with platinum-based chemotherapy and/or radiotherapy. Genotypes containing the African allele were associated with poor OS/DFS in comparison with homozygous genotypes harboring the white allele. Analyses show that ancestry-related alleles could act as eQTLs in HNSCC and support the association of ancestry-related genetic factors with survival disparities in patients diagnosed with oral cavity and laryngeal cancer. Cancer 2017;123:849-60. © 2016 American Cancer Society. © 2016 American Cancer Society.

Children's 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger.

PubMed

Gibb, Brandon E; Johnson, Ashley L; Benas, Jessica S; Uhrlass, Dorothy J; Knopik, Valerie S; McGeary, John E

2011-09-01

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene; 5-HTTLPR). In the current study, we tested a gene×environment (G×E) model of risk for attentional biases. We hypothesised that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention.

Children’s 5-HTTLPR genotype moderates the link between maternal criticism and attentional biases specifically for facial displays of anger

PubMed Central

Gibb, Brandon E.; Johnson, Ashley L.; Benas, Jessica S.; Uhrlass, Dorothy J.; Knopik, Valerie S.; McGeary, John E.

2011-01-01

Theorists have proposed that negative experiences in childhood may contribute to the development of experience-specific information-processing biases, including attentional biases. There are also clear genetic influences on cognitive processes, with evidence that polymorphisms in specific candidate genes may moderate the impact of environmental stress on attentional biases (e.g., a functional polymorphism in the serotonin transporter gene [5-HTTLPR]). In the current study, we tested a gene × environment (G × E) model of risk for attentional biases. We hypothesized that children whose mothers exhibit high levels of expressed emotion criticism (EE-Crit) would display attentional biases specifically for angry, but not happy or sad, faces, and that this link would be stronger among children carrying one or two copies of the 5-HTTLPR short allele than among those homozygous for the long allele. Results generally supported these hypotheses, though we found that carriers of the 5-HTTLPR short allele who also had a critical mother exhibited attentional avoidance of angry faces rather than preferential attention. PMID:21895572

Growth hormone 1 (GH1) gene and performance and post‐race rectal temperature during the South African Ironman triathlon

PubMed Central

Walpole, B; Noakes, T D; Collins, M

2006-01-01

Background Some studies have suggested that the insertion allele of the ACE gene is associated with endurance performance, including the Ironman triathlon. It is possible that this association is due to genetic linkage between the ACE I/D locus and the T/A variant in intron 4 of the neighbouring GH1 gene. The A variant is associated with lower levels of growth hormone production. Growth hormone has multiple effects, especially on metabolism during exercise and recovery from exercise. Its production during exercise has also been shown to stimulate sweat rate and heat loss. Objective To determine whether the GH1 gene is associated with the performance and/or post‐race rectal temperatures of competitors in the South African Ironman triathlon. Methods A total of 169 of the fastest finishing white male triathletes who completed the 2000 and/or 2001 South African Ironman triathlon and 155 control subjects were genotyped for the T/A variant in the GH1 gene. Post‐race rectal temperature was also determined in 103 of these triathletes. Results There was no significant difference in the frequency of this polymorphism in the GH1 gene when the fastest finishing triathletes were compared with the control subjects. Post‐race rectal temperatures were, however, significantly higher in those triathletes with an AA genotype (mean (SD) 37.7 (0.8)°C) compared with those with a TT genotype (37.2 (0.8)°C) (p  =  0.019). Conclusions The T/A polymorphism in intron 4 of the GH1 gene was not associated with performance of the fastest finishers of the South African Ironman triathlon. Post‐race rectal temperatures were, however, significantly higher in the fastest finishing athletes, who were homozygous for a GH1 genotype associated with lower growth hormone production. PMID:16432002

The association of variants in the FTO gene with longitudinal body mass index profiles in non-Hispanic white children and adolescents.

PubMed

Hallman, D M; Friedel, V C; Eissa, M A H; Boerwinkle, E; Huber, J C; Harrist, R B; Srinivasan, S R; Chen, W; Dai, S; Labarthe, D R; Berenson, G S

2012-01-01

To investigate possible age-related changes in associations between polymorphisms in the fat mass and obesity-associated (FTO) gene and higher body mass index (BMI). Multilevel mixed regression models were used to examine associations between four FTO variants and longitudinal BMI profiles in non-Hispanic white and African American children and adolescents 8-17 years of age from two different longitudinal cohort studies, the Bogalusa Heart Study (BHS) and Project HeartBeat! (PHB). In the BHS, there were 1551 examinations of 478 African Americans and 3210 examinations of 1081 non-Hispanic whites; in PHB, there were 971 examinations of 131 African Americans and 4458 examinations of 505 non-Hispanic whites. In African Americans, no significant FTO associations with BMI were found. In non-Hispanic whites, linkage disequilibrium among all four variants made haplotype analysis superfluous, so we focused on the single-nucleotide polymorphism, rs9939609. In longitudinal multilevel models, the A/A genotype of rs9939609 was associated with higher BMI in non-Hispanic whites in both cohorts at all ages. A significant age-by-genotype interaction found only in the BHS cohort predicted that in those with the A/A genotype, BMI would be ∼0.7 kg m(-2) higher at age 8 and ∼1.6 kg m(-2) higher at age 17 than in those with A/T or T/T genotypes. The design of PHB limited follow-up of any single individual to 4 years, and may have reduced the ability to detect any age-by-genotype interaction in this cohort. The A/A genotype of rs9939609 in the FTO gene is associated with higher longitudinal BMI profiles in non-Hispanic whites from two different cohorts. The association may change with age, with the A/A genotype being associated with a larger BMI difference in late adolescence than in childhood, though this was observed only in the BHS cohort and requires verification.

Genome-Wide Prediction of the Polymorphic Ser Gene Family in Tetrahymena thermophila Based on Motif Analysis

PubMed Central

Ponsuwanna, Patrath; Kümpornsin, Krittikorn; Chookajorn, Thanat

2014-01-01

Even though antigenic variation is employed among parasitic protozoa for host immune evasion, Tetrahymena thermophila, a free-living ciliate, can also change its surface protein antigens. These cysteine-rich glycosylphosphatidylinositol (GPI)-linked surface proteins are encoded by a family of polymorphic Ser genes. Despite the availability of T. thermophila genome, a comprehensive analysis of the Ser family is limited by its high degree of polymorphism. In order to overcome this problem, a new approach was adopted by searching for Ser candidates with common motif sequences, namely length-specific repetitive cysteine pattern and GPI anchor site. The candidate genes were phylogenetically compared with the previously identified Ser genes and classified into subtypes. Ser candidates were often found to be located as tandem arrays of the same subtypes on several chromosomal scaffolds. Certain Ser candidates located in the same chromosomal arrays were transcriptionally expressed at specific T. thermophila developmental stages. These Ser candidates selected by the motif analysis approach can form the foundation for a systematic identification of the entire Ser gene family, which will contribute to the understanding of their function and the basis of T. thermophila antigenic variation. PMID:25133747

Development and characterization of microsatellite markers in the African forest elephant (Loxodonta cyclotis).

PubMed

Gugala, Natalie A; Ishida, Yasuko; Georgiadis, Nicholas J; Roca, Alfred L

2016-07-26

African elephants comprise two species, the savanna elephant (Loxodonta africana) and the forest elephant (L. cyclotis), which are distinct morphologically and genetically. Forest elephants are seriously threatened by poaching for meat and ivory, and by habitat destruction. However, microsatellite markers have thus far been developed only in African savanna elephants and Asian elephants, Elephas maximus. The application of microsatellite markers across deeply divergent lineages may produce irregular patterns such as large indels or null alleles. Thus we developed novel microsatellite markers using DNA from two African forest elephants. One hundred microsatellite loci were identified in next generation shotgun sequences from two African forest elephants, of which 53 were considered suitable for testing. Twenty-three microsatellite markers successfully amplified elephant DNA without amplifying human DNA; these were further characterized in 15 individuals from Lope National Park, Gabon. Three of the markers were monomorphic and four of them carried only two alleles. The remaining sixteen polymorphic loci carried from 3 to 8 alleles, with observed heterozygosity ranging from 0.27 to 0.87, expected heterozygosity from 0.40 to 0.86, and the Shannon diversity index from 0.73 to 1.86. Linkage disequilibrium was not detected between loci, and no locus deviated from Hardy-Weinberg equilibrium. The markers developed in this study will be useful for genetic analyses of the African forest elephant and contribute to their conservation and management.

Novel genetic risk factors for asthma in African American children: Precision Medicine and the SAGE II Study.

PubMed

White, Marquitta J; Risse-Adams, O; Goddard, P; Contreras, M G; Adams, J; Hu, D; Eng, C; Oh, S S; Davis, A; Meade, K; Brigino-Buenaventura, E; LeNoir, M A; Bibbins-Domingo, K; Pino-Yanes, M; Burchard, E G

2016-07-01

Asthma, an inflammatory disorder of the airways, is the most common chronic disease of children worldwide. There are significant racial/ethnic disparities in asthma prevalence, morbidity, and mortality among US children. This trend is mirrored in obesity, which may share genetic and environmental risk factors with asthma. The majority of asthma biomedical research has been performed in populations of European decent. We sought to identify genetic risk factors for asthma in African American children. We also assessed the generalizability of genetic variants associated with asthma in European and Asian populations to African American children. Our study population consisted of 1227 (812 asthma cases, 415 controls) African American children with genome-wide single nucleotide polymorphism (SNP) data. Logistic regression was used to identify associations between SNP genotype and asthma status. We identified a novel variant in the PTCHD3 gene that is significantly associated with asthma (rs660498, p = 2.2 × 10(-7)) independent of obesity status. Approximately 5 % of previously reported asthma genetic associations identified in European populations replicated in African Americans. Our identification of novel variants associated with asthma in African American children, coupled with our inability to replicate the majority of findings reported in European Americans, underscores the necessity for including diverse populations in biomedical studies of asthma.

Selection on the human bitter taste gene, TAS2R16, in Eurasian populations.

PubMed

Li, Hui; Pakstis, Andrew J; Kidd, Judith R; Kidd, Kenneth K

2011-06-01

Bitter taste is one of the most important senses alerting humans to noxious foods. In gatherer communities, sensitivity to bitterness is presumably advantageous because of various noxious plants. TAS2R16 is the gene coding the taste receptor molecules for some of the most common toxins in plants. A previous study of this gene indicated selection has increased the frequency of a derived allele in this gene that arose before the human expansion out of Africa. We have applied a different methodology for detecting selection, the Long Range Haplotype (LRH) analysis, to TAS2R16 in a larger sampling of populations from around the world. The haplotype with the derived alleles at both the functional polymorphism and a polymorphism in the regulatory region of TAS2R16 showed evidence for recent positive selection in most of the Eurasian populations, though the highest selection signal occurs in Mbuti Pygmies, an African hunter-gatherer group. In Eurasia, only populations of Mesopotamia and the southeast coast of China have no signals of selection. The evidence of recent selection found in most Eurasian populations differs from the geographic pattern seen in the earlier study of selection. One can speculate that the difference may result from a gathering lifestyle extending into the most recent 10,000 yrs and the need to recognize newly encountered bitter natural toxins as populations expanded into new environments and the biota changes with the ending of the most recent ice age. Alternatively, the promoter region variant may be a marker for altered function beyond what the derived amino acid allele conferred.

Functionally Relevant Microsatellite Markers From Chickpea Transcription Factor Genes for Efficient Genotyping Applications and Trait Association Mapping

PubMed Central

Kujur, Alice; Bajaj, Deepak; Saxena, Maneesha S.; Tripathi, Shailesh; Upadhyaya, Hari D.; Gowda, C.L.L.; Singh, Sube; Jain, Mukesh; Tyagi, Akhilesh K.; Parida, Swarup K.

2013-01-01

We developed 1108 transcription factor gene-derived microsatellite (TFGMS) and 161 transcription factor functional domain-associated microsatellite (TFFDMS) markers from 707 TFs of chickpea. The robust amplification efficiency (96.5%) and high intra-specific polymorphic potential (34%) detected by markers suggest their immense utilities in efficient large-scale genotyping applications, including construction of both physical and functional transcript maps and understanding population structure. Candidate gene-based association analysis revealed strong genetic association of TFFDMS markers with three major seed and pod traits. Further, TFGMS markers in the 5′ untranslated regions of TF genes showing differential expression during seed development had higher trait association potential. The significance of TFFDMS markers was demonstrated by correlating their allelic variation with amino acid sequence expansion/contraction in the functional domain and alteration of secondary protein structure encoded by genes. The seed weight-associated markers were validated through traditional bi-parental genetic mapping. The determination of gene-specific linkage disequilibrium (LD) patterns in desi and kabuli based on single nucleotide polymorphism-microsatellite marker haplotypes revealed extended LD decay, enhanced LD resolution and trait association potential of genes. The evolutionary history of a strong seed-size/weight-associated TF based on natural variation and haplotype sharing among desi, kabuli and wild unravelled useful information having implication for seed-size trait evolution during chickpea domestication. PMID:23633531

Improving minority blood donation: anthropologic approach in a migrant community.

PubMed

Grassineau, Dominique; Papa, Kassim; Ducourneau, Axel; Duboz, Priscillia; Boëtsch, Gilles; Chiaroni, Jacques

2007-03-01

As a result of blood group polymorphism, distinctive blood types have evolved in populations around the world. In countries with large migrant populations, finding rare blood types for transfusion can be challenging. This is especially true for sub-Saharan African immigrants living in countries with predominantly European populations. This problem is further compounded by hereditary disorders such as sickle cell disease and by traditional cultural values that discourage routine donation. The purpose of this report is to describe the drive to recruit more safe rare blood type donors in a Comorian immigrant community living in Marseilles, France. With a culturally adapted message developed on an anthropologic approach and working in close collaboration with scientific and medical members of the Comorian community, it is proposed that this population be sensitized with the gift of blood. Targeted collection of specific sub-Saharan African blood types was achieved. Taking into account the high rate of infectious markers among products collected in this targeted collection, however, it was decided to promote blood donation in this minority by addressing people directly toward our principal blood center site. Since setup of this adapted communication, regular donors present themselves spontaneously without community pressure. Infectious markers rate is then equal to general blood donor population's rate. The results of this drive demonstrate the utility of an anthropologic approach and cultural mediation in identifying donors with specific blood types in migrant communities and recruiting second-generation donors. The techniques described in this study could also be applied to collection of other tissues including organs and peripheral blood progenitor cells in minorities.

A Comprehensive Systems Biology Approach to Studying Zika Virus.

PubMed

May, Meghan; Relich, Ryan F

2016-01-01

Zika virus (ZIKV) is responsible for an ongoing and intensifying epidemic in the Western Hemisphere. We examined the complete predicted proteomes, glycomes, and selectomes of 33 ZIKV strains representing temporally diverse members of the African lineage, the Asian lineage, and the current outbreak in the Americas. Derivation of the complete selectome is an 'omics' approach to identify distinct evolutionary pressures acting on different features of an organism. Employment of the M8 model did not show evidence of global diversifying selection acting on the ZIKV polyprotein; however, a mixed effect model of evolution showed strong evidence (P<0.05) for episodic diversifying selection acting on specific sites. Single nucleotide polymorphisms (SNPs) were predictably frequent across strains relative to the derived consensus sequence. None of the 9 published detection procedures utilize targets that share 100% identity across the 33 strains examined, indicating that ZIKV escape from molecular detection is predictable. The predicted O-linked glycome showed marked diversity across strains; however, the N-linked glycome was highly stable. All Asian and American strains examined were predicted to include glycosylation of E protein ASN154, a modification proposed to mediate neurotropism, whereas the modification was not predicted for African strains. SNP diversity, episodic diversifying selection, and differential glycosylation, particularly of ASN154, may have major biological implications for ZIKV disease. Taken together, the systems biology perspective of ZIKV indicates: a.) The recently emergent Asian/American N-glycotype is mediating the new and emerging neuropathogenic potential of ZIKV; and b.) further divergence at specific sites is predictable as endemnicity is established in the Americas.

Rapid microsatellite marker development for African mahogany (Khaya senegalensis, Meliaceae) using next-generation sequencing and assessment of its intra-specific genetic diversity.

PubMed

Karan, M; Evans, D S; Reilly, D; Schulte, K; Wright, C; Innes, D; Holton, T A; Nikles, D G; Dickinson, G R

2012-03-01

Khaya senegalensis (African mahogany or dry-zone mahogany) is a high-value hardwood timber species with great potential for forest plantations in northern Australia. The species is distributed across the sub-Saharan belt from Senegal to Sudan and Uganda. Because of heavy exploitation and constraints on natural regeneration and sustainable planting, it is now classified as a vulnerable species. Here, we describe the development of microsatellite markers for K. senegalensis using next-generation sequencing to assess its intra-specific diversity across its natural range, which is a key for successful breeding programs and effective conservation management of the species. Next-generation sequencing yielded 93,943 sequences with an average read length of 234 bp. The assembled sequences contained 1030 simple sequence repeats, with primers designed for 522 microsatellite loci. Twenty-one microsatellite loci were tested with 11 showing reliable amplification and polymorphism in K. senegalensis. The 11 novel microsatellites, together with one previously published, were used to assess 73 accessions belonging to the Australian K. senegalensis domestication program, sampled from across the natural range of the species. STRUCTURE analysis shows two major clusters, one comprising mainly accessions from west Africa (Senegal to Benin) and the second based in the far eastern limits of the range in Sudan and Uganda. Higher levels of genetic diversity were found in material from western Africa. This suggests that new seed collections from this region may yield more diverse genotypes than those originating from Sudan and Uganda in eastern Africa. © 2011 Blackwell Publishing Ltd.

A decade of research on the 17q12-21 asthma locus: Piecing together the puzzle.

PubMed

Stein, Michelle M; Thompson, Emma E; Schoettler, Nathan; Helling, Britney A; Magnaye, Kevin M; Stanhope, Catherine; Igartua, Catherine; Morin, Andréanne; Washington, Charles; Nicolae, Dan; Bønnelykke, Klaus; Ober, Carole

2018-01-04

Chromosome 17q12-21 remains the most highly replicated and significant asthma locus. Genotypes in the core region defined by the first genome-wide association study correlate with expression of 2 genes, ORM1-like 3 (ORMDL3) and gasdermin B (GSDMB), making these prime candidate asthma genes, although recent studies have implicated gasdermin A (GSDMA) distal to and post-GPI attachment to proteins 3 (PGAP3) proximal to the core region as independent loci. We review 10 years of studies on the 17q12-21 locus and suggest that genotype-specific risks for asthma at the proximal and distal loci are not specific to early-onset asthma and mediated by PGAP3, ORMDL3, and/or GSDMA expression. We propose that the weak and inconsistent associations of 17q single nucleotide polymorphisms with asthma in African Americans is due to the high frequency of some 17q alleles, the breakdown of linkage disequilibrium on African-derived chromosomes, and possibly different early-life asthma endotypes in these children. Finally, the inconsistent association between asthma and gene expression levels in blood or lung cells from older children and adults suggests that genotype effects may mediate asthma risk or protection during critical developmental windows and/or in response to relevant exposures in early life. Thus studies of young children and ethnically diverse populations are required to fully understand the relationship between genotype and asthma phenotype and the gene regulatory architecture at this locus. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.