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1

Bilateral transverse sinus thrombosis secondary to a homozygous C677T MTHFR gene mutation.  

PubMed

We describe the case of a previously healthy young man who presented with headache, diplopia, nausea, vomiting, and bilateral papilledema. Magnetic resonance venography of the brain revealed thrombosis of the right transverse sinus. Blood tests showed elevated homocysteine levels, and coagulation studies revealed a homozygous C677T mutation and a heterozygous A1298C mutation of the methylenetetrahydrofolate reductase (MTHFR) gene. The patient had no other etiology for venous thrombosis. We recommend screening patients who present with sinus thrombosis for MTHFR gene mutations. PMID:18666857

Kanaan, Ziad M; Mahfouz, Rami; Taher, Ali; Sawaya, Raja A

2008-09-01

2

Mutations C677T and A1298C of the 5,10-methylenetetrahydrofolate reductase gene and fasting plasma homocysteine levels are not associated with the increased risk of venous thromboembolic disease.  

PubMed

Mild hyperhomocysteinemia is associated with homozygosity for the thermolabile variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) and could increase the risk of venous thromboembolic disease (VTD). Recently, the second A1298C mutation of the MTHFR gene was described. The present study aimed to analyze both mutations of the MTHFR gene and plasma homocysteine levels in subjects with VTD. The study groups comprised 146 patients with VTD and 100 healthy subjects. There were no statistical differences in carrier frequency and allelic frequency for both A1298C and C677T mutations, nor were there any differences encountered between subjects with VTD and controls in either plasma homocysteine levels or according to C677T or A1298C genotypes of MTHFR. In our VTD patients and controls, neither MTHFR 677CT/1298CC nor MTHFR 677TT/1298CC combined genotypes were observed; double heterozygotes (A1298C/C677T) were represented only in 11% of VTD patients, and in 15% of the controls. In conclusion, the polymorphisms C677T and A1298C of MTHFR and fasting plasma homocysteine levels do not seem to be significant risk factors for venous thromboembolic disease. PMID:12138370

Domagala, T B; Adamek, L; Nizankowska, E; Sanak, M; Szczeklik, A

2002-07-01

3

MTHFR Gene C677T Polymorphism in Autism Spectrum Disorders  

PubMed Central

Aim. Autism is a subgroup of autism spectrum disorders, classified as a heterogeneous neurodevelopmental disorder and symptoms occur in the first three years of life. The etiology of autism is largely unknown, but it has been accepted that genetic and environmental factors may both be responsible for the disease. Recent studies have revealed that the genes involved in the folate/homocysteine pathway may be risk factors for autistic children. In particular, C677T polymorphism in the MTHFR gene as a possible risk factor for autism is still controversial. We aimed to investigate the possible effect of C677T polymorphism in a Turkish cohort. Methods. Autism patients were diagnosed by child psychiatrists according to DSM-IV and DSM-V criteria. A total of 98 children diagnosed as autistic and 70 age and sex-matched children who are nonautistic were tested for C677T polymorphism. This polymorphism was studied by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. Results. MTHFR 677T-allele frequency was found to be higher in autistic children compared with nonautistic children (29% versus 24%), but it was not found statistically significant. Conclusions. We conclude that other MTHFR polymorphisms such as A1298C or other folate/homocysteine pathway genes may be studied to show their possible role in autism. PMID:25431675

Oztop, Didem Behice; Ozkul, Yusuf

2014-01-01

4

Elevated plasma homocysteine is positively associated with age independent of C677T mutation of the methylenetetrahydrofolate reductase gene in selected Egyptian subjects  

PubMed Central

This study aimed to evaluate the plasma homocysteine (tHcy) and folate levels as well as the methylenetetrahydrofolate reductase (MTHFR) C677T mutation in Egyptian subjects. Fasting total homocysteine (tHcy) and the (MTHFR) C677T mutation were evaluated in 50 healthy young control males (age 35-50 years, Gp1), 50 elderly males age ranged between 50-75 years without any cardiovascular diseases (Gp2) and 50 age matched elderly male patients (Gp3) with myocardial infarction. There was a significant elevation of plasma tHcy in the patients group and Gp2 compared to the young control group (Gp1). The total plasma homocysteine (tHcy) in the control group, Gp2 and the patients group were 17.99 ± 9.76, 39.9 ± 20.06 and 43.8 ± 13.13 ?mol/L respectively. The frequency of the TT genotype was 12% in the patient group compared with 8 % in the young healthy controls and elderly subjects (Gp2). The CT genotype constituted 36%, 48% and 44% in the control group, Gp2 and the patients group respectively. There was no significant difference in the occurrence of the TT genotype between the studied groups. Plasma tHcy correlated positively with age, total cholesterol, urea, creatinine, glucose levels and carotid intimal thickness (CIT). Conclusion: The MTHFR mutation does not seem to be associated with either high tHcy or the occurrence of cardiovascular diseases in the studied patients. However, elevated plasma tHcy level positively correlates with age in the studied subjects. PMID:15912197

2004-01-01

5

Association of C677T transition of the human methylenetetrahydrofolate reductase (MTHFR) gene with male infertility.  

PubMed

The human methylenetetrahydrofolate reductase (MTHFR) gene encodes one of the key enzymes in folate metabolism. This gene is located on chromosome 1 (1p36.3), which has 12 exons. The aim of the present study was to investigate the possible association of the two (C677T and A1298C) polymorphisms of this gene with male infertility. In a case-control study, 250 blood samples were collected from IVF centres in Sari and Babol (Iran): 118 samples were from oligospermic men and 132 were from controls. Two single nucleotide polymorphisms of the MTHFR genotype were detected using polymerase chain reaction-restriction fragment length polymorphism. There was no association found between the A1298C variant and male infertility. However, carriers of the 677T allele (CT and TT genotypes) were at a higher risk of infertility than individuals with other genotypes (odds ratio 1.84; 95% confidence interval 1.11-3.04; P=0.0174). Structural analysis of human MTHFR flavoprotein showed that C677T transition played an important role in the change in affinity of the MTHFR-Flavin adenine dinucleotide binding site. Based on our results, we suggest that C677T transition in MTHFR may increase the risk of male infertility, and detection of the C677T polymorphism biomarker may be helpful in the screening of idiopathic male infertility. PMID:25412139

Karimian, Mohammad; Colagar, Abasalt Hosseinzadeh

2014-11-21

6

Infant C677T mutation in MTHFR, maternal periconceptional vitamin use, and cleft lip.  

PubMed

Studies have reported an association between homozygosity for a variant form of the methylenetetrahydrofolate reductase (MTHFR) gene and risk for neural tube defects. Because of MTHFR's involvement with folate metabolism and evidence that maternal use of a multivitamin with folic acid in early pregnancy reduces risk for cleft lip with or without cleft palate (CLP), we hypothesized that infants homozygous for the C677T genotype would be at increased risk for CLP because of lower MTHFR enzymatic activity. Data were derived from a large population-based, case-control study of fetuses and liveborn infants among a cohort of 1987 to 1989 California births. The analyses involved 310 infants with isolated CLP whose mothers completed a telephone interview and whose DNA was available from newborn screening blood specimens and involved 383 control infants without a congenital anomaly whose mothers completed a telephone interview and whose DNA was available. Cases and controls were genotyped TT if homozygous for the C677T allele, CT if heterozygous for the C677T allele, and CC if homozygous for the C677 (wild-type) allele. Odds ratios for CLP were 0.89 (0.55 to 1.4) and 0.78 (0.56 to 1.1) for infants with TT versus CC and infants with CT versus CC genotypes, respectively. Compared with the CC genotype, the odds ratios for CLP among infants with the TT genotype were 0.74 (0.39 to 1.4) for those infants whose mothers were users and 1.4 (0.54 to 3.6) for those infants whose mothers were not users of multivitamins containing folic acid periconceptionally. The two estimates were not statistically heterogeneous (P = 0.30). Our results did not indicate increased risks for CLP among infants homozygous for the C677T genotype, nor do they indicate an interaction between infant C677T genotype and maternal multivitamin use on the occurrence of CLP. PMID:9843036

Shaw, G M; Rozen, R; Finnell, R H; Todoroff, K; Lammer, E J

1998-11-16

7

Myocardial infarction in a newborn heterozygous for the MTHFR C677T mutation.  

PubMed

Neonatal myocardial infarction secondary to congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia, and unknown causes has been previously reported. We now report an infant who suffered a massive myocardial infarction during birth, requiring extensive resuscitation and aggressive management. A thrombus, the origin of which was not detected on autopsy, was found occluding the proximal left coronary artery several hours after birth. Genetic studies revealed a single copy variant of the MTHFR C677T mutation that we speculate may have predisposed the infant to coronary thrombosis. PMID:22339112

Clark, Amy B; Stokes, Theophil A; Krous, Henry F; Carbine, Douglas N

2012-01-01

8

Methylenetetrahydrofolate reductase C677T gene polymorphism and colorectal cancer risk: A case-control study.  

PubMed

We designed a case-control study to determine the plasma homocysteine (Hcy) level and evaluate the potential role of the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in colorectal cancer (CRC). Total Hcy was quantified using the fluorescence polarization immunoassay (FPIA) on the IMx analyzer. Genomic DNA was analyzed by the real-time polymerase chain reaction (RT-PCR). The plasma levels of Hcy in the CRC group (12.63±3.11 ?mol/l) were significantly higher compared with those in the control group (10.87±2.42 ?mol/l; P<0.05). The frequency of the MTHFR 677TT genotype in CRC patients was markedly high. The MTHFR 677TT genotype was significantly correlated with an increased risk of CRC (odds ratio, 1.671; 95% confidence interval, 1.094-2.553; P=0.018). This study suggests that the MTHFR C677T polymorphism indicates susceptibility to CRC and is correlated with CRC pathogenesis, suggesting that the homozygous variant MTHFR C677T polymorphism is a candidate risk factor for CRC. PMID:22844384

Yin, Guancheng; Ming, Hanxin; Zheng, Xiao; Xuan, Yi; Liang, Jianwei; Jin, Xing

2012-08-01

9

Increased frequency of combined methylenetetrahydrofolate reductase C677T and A1298C mutated alleles in spontaneously aborted embryos.  

PubMed

The pathogenesis of spontaneous abortion is complex, presumably involving the interaction of several genetic and environmental factors. The methylenetetrahydrofolate reductase (MTHFR) gene C677T and A1298C polymorphisms are commonly associated with defects in folate dependent homocysteine metabolism and have been implicated as risk factors for recurrent embryo loss in early pregnancy. In the present study we have determined the prevalence of combined MTHFR C677T and A1298C polymorphisms in DNA samples from spontaneously aborted embryos (foetal death between sixth and twentieth week after conception) and adult controls using solid-phase minisequencing technique. There was a significant odds ratio of 14.2 (95% CI 1.78-113) in spontaneously aborted embryos comparing the prevalence of one or more 677T and 1298C alleles vs the wild type combined genotype (677CC/1298AA), indicating that the MTHFR polymorphisms may have a major impact on foetal survival. Combined 677CT/1298CC, 677TT/1298AC or 677TT/1298CC genotypes, which contain three or four mutant alleles, were not detected in any of the groups, suggesting complete linkage disequilibrium between the two polymorphisms. The present finding of high prevalence of mutated MTHFR genotypes in spontaneously aborted embryos emphasises the potential protective role of periconceptional folic acid supplementation. PMID:11938441

Zetterberg, Henrik; Regland, Björn; Palmér, Mona; Ricksten, Anne; Palmqvist, Lars; Rymo, Lars; Arvanitis, Demetrios A; Spandidos, Demetrios A; Blennow, Kaj

2002-02-01

10

C677T gene polymorphism of MTHFR and metabolic syndrome: response to dietary intervention.  

PubMed

BackgroundMethylenetetrahydrofolate reductase (MTHFR) gene polymorphisms were found associated with body mass index (BMI)-defined obesity and lean mass.The aim of our study was to examine the role of the C677T MTHFR gene polymorphism in the response to diet in the management of metabolic syndrome. We investigated the body composition and metabolic factor changes after an hysocaloric balanced diet (HBD), in Italian obese women affected by metabolic syndrome (MS).MethodsForty four obese women affected by MS were eligible for the study. A HBD for 12 weeks was assigned. Study participation included a complete screening for dietary habits, anthropometry, body composition, blood biochemical markers and C677T MTHFR polymorphism genotyping. The study has been registrated by ClinicalTrials.gov Id: NCT01890070.ResultsThe highest number of responders to HBD nutritional intervention were T(¿) carriers (p¿¿¿0.05). In the 81% of the total population a loss of Total Body Lean was observed. A significative loss (p¿¿¿0.05) of Total Body Lean was observed in the 47% of T(¿) carriers and in the 53% of T(+) carriers. Diastolic and systolic blood pressure, and waist circumference were reduced (p¿¿¿0.05). The prevalence of MS parameters decreased by 84% for systolic and diastolic blood pressure; 79,5% for HDL cholesterol, 82% for fasting glucose and 77% for triglycerides.ConclusionsMTHFR genetic variations analysis would be an innovative tool for the nutritional assessment. Our data provide the basis for personalized dietary recommendations based on the individual¿s genetic makeup and nutritional status.Trial registrationThe study has been registrated by ClinicalTrials.gov Id: NCT01890070. PMID:25432492

Di Renzo, Laura; Marsella, Luigi; Sarlo, Francesca; Soldati, Laura; Gratteri, Santo; Abenavoli, Ludovico; De Lorenzo, Antonino

2014-11-29

11

Pediatric stroke and methylenetetrahydrofolate reductase polymorphisms: an examination of C677T and A1298C mutations.  

PubMed

Although rare in children, stroke is becoming increasingly recognized as an important cause of morbidity and mortality with an annual incidence of approximately 3 per 100,000 per year. While several studies have documented the underlying mechanisms and pathogenesis related to stroke in adults, including genetic and acquired prothrombotic conditions, the data available on similar conditions in children is limited. Evidence suggests that mutations in methylenetetrahydrofolate reductase (MTHFR) appear to be linked with hyperhomocysteinemia (HHC) and cerebral-thrombotic events in children. While the C677T common missense mutation is the best-characterized MTHFR polymorphism, another common missense mutation, A1298C also exists. A recent study of children demonstrated that the homozygous form of C677T polymorphism occurred two-times as often in those with stroke versus healthy controls. In our retrospective chart review of 33 children seen at Children's Hospital of Orange County from January 1, 2000 to September 30, 2003 with the diagnosis of stroke, we examined both the C677T and A1298C polymorphisms for occurrence and type. In the subset (n=21), which excluded those with a confounding disorder, we observed a significant increase in the frequency of A1298C and C677T homozygosity (0.25 [p=0.01] and 0.20 [p=0.100], respectively); expected rate: (0.06 and 0.08, respectively). Our observed rates of heterozygosity for both MTHFR mutations (0.35 and 0.40, respectively) were consistent with expected rates (0.28 and 0.38, respectively). In all subjects, homocysteine (HC) levels were normal. The results of our study suggest that mutations in MTHFR are associated with pediatric stroke. However, additional studies are required to confirm our findings and to determine if this relationship is causal. PMID:16282888

Rook, James L; Nugent, Diane J; Young, Guy

2005-11-01

12

Higher incidence of C677T polymorphism of the MTHFR gene in North Indian patients with vascular disease.  

PubMed

Homocysteine is a sulfur-containing amino acid, which is derived from dietary methionine. Hyperhomocysteinemia has been implicated in vascular disease for over a decade now, and can be treated with B vitamins. Among its causes is polymorphism of the MTHFR gene, the most common being the cytidine to thymidine at position 677 (MTHFR C677T), which gives rise to three genotypes - normal homozygous CC, heterozygous CT and homozygous variant TT. An attempt was made to ascertain the prevalence of this MTHFR C677T in our population so that preventive measures may accordingly be instituted. Blood samples from 70 patients with vascular disease and 70 healthy controls were analyzed for plasma homocysteine levels (chemiluminescent immunoassay) and for the presence of MTHFR C677T (polymerase chain reaction analysis). Homocysteine was higher in the homozygous subjects (TT genotype) than in the heterozygous (CT genotype). In patients, the frequency of the C allele was significantly lower, and that of the T allele was significantly higher than the corresponding frequencies in controls. In conclusion, the North Indian urban population has higher homocysteine levels associated with the TT genotype. Hence, instituting measures towards reduction of homocysteine levels in the population would probably reduce the incidence and morbidity of vascular disease in our population. PMID:22375042

Bhargava, S; Ali, A; Parakh, R; Saxena, R; Srivastava, L M

2012-04-01

13

Evaluation of methylenetetrahydrofolate reductase gene variant (C677T) as risk factor for bipolar disorder.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the metabolism of folate, whose role in bipolar disorder is controversial. The aim of the present study was to assess the risk of MTHFR C677T polymorphism for bipolar disorder. The author performed a meta-analysis and pooled data from individual case-control studies that examined the association between C677T polymorphism and bipolar disorder (meta-analysis: 8 studies, 1457 cases and 2169 controls).The pooled Odd Ratios (OR) were estimated by both fixed effects and random effects models. The meta-analysis with fixed effects showed that there was 71% heterogeneity between the eight studies. The fixed effect pooled OR was 1.07 (95% CI; 0.98 to 1.17) and Cochran Q was 24.13 (df = 7; p=0.0011). The study is significant and shows meager association. The random effect pooled OR was 1.07(95% CI; 0.87 to 1.32) and Cochran Q was 24.13 (df = 7; p=0.0011). The random effect pooled OR was also significant and shows meager association between MTHFR C677T genotype and bipolar disorder. PMID:21955385

Rai, V

2011-01-01

14

A newborn case with perinatal-lethal Gaucher disease due to R463H homozygosity complicated by C677T homozygosity in the MTHFR gene.  

PubMed

Perinatal-lethal Gaucher disease is very rare and is considered a variant of type 2 Gaucher disease that occurs in the neonatal period. The most distinct features of perinatal-lethal Gaucher disease are non-immune hydrops fetalis, in utero fetal demise and neonatal distress. In some cases without hydrops, neurological signs occur in the first week of life and lead to death within 3 months. Less common signs of the disease are hepatosplenomegaly, ichthyosis, arthrogryposis and facial dysmorphy. We describe a preterm neonate with Gaucher disease homozygous for R463H mutation in GBA gene who showed severe neurologic signs in addition to refractory thrombocytopenia, hepatosplenomagaly, direct hyperbilirubinemia, facial dysmorphy and ichthyosiform skin abnormalities in addition to having thrombosis in portal and splenic veins possibly due to homozygosity for C677T mutation in MTHFR gene. To the best of our knowledge, this is the first case homozygous for the GBA R463H mutation resulting in Gaucher disease with a concomitant homozygous MTHFR C677T mutation. PMID:21823541

Akdag, Arzu; O?uz, Serife Suna; Ezgü, Fatih; Erdeve, Omer; Ura?, Nurdan; Dilmen, U?ur

2011-01-01

15

Methylenetetrahydrofolate reductase C677T gene polymorphism and essential hypertension: A meta-analysis of 10,415 subjects  

PubMed Central

The methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism has been suggested to be associated with the risk of essential hypertension (EH), however, results remain inconclusive. To investigate this association, the present meta-analysis of 27 studies including 5,418 cases and 4,997 controls was performed. The pooled odds ratio (OR) and its corresponding 95% confidence interval were calculated using the random-effects model. A significant association between the MTHFR C677T gene polymorphism and EH was found under the allelic (OR, 1.32; 95% CI, 1.20–1.45; P=0.000), dominant (OR, 1.39; 95% CI, 1.25–1.55; P=0.000), recessive (OR, 1.38; 95% CI, 1.18–1.62; P=0.000), homozygote (OR, 1.59; 95% CI, 1.32–1.92; P=0.000), and heterozygote (OR, 1.32; 95% CI, 1.20–1.45; P=0.000) genetic models. A strong association was also revealed in subgroups, including Asian, Caucasian and Chinese. The Japanese subgroup did not show any significant association under all models. Meta-regression analyses suggested that the study design was a potential source of heterogeneity, whereas the subgroup analysis additionally indicated that the population origin may also be an explanation. Another subgroup analysis revealed that hospital-based studies have a stronger association than population-based studies, however, the former suffered a greater heterogeneity. Funnel plot and Egger’s test manifested no evidence of publication bias. In conclusion, the present study supports the evidence for the association between the MTHFR C677T gene polymorphism and EH in the whole population, as well as in subgroups, such as Asian, Caucasian and Chinese. The carriers of the 677T allele are susceptible to EH. PMID:25054014

YANG, KE-MING; JIA, JIAN; MAO, LI-NA; MEN, CHEN; TANG, KANG-TING; LI, YAN-YAN; DING, HAI-XIA; ZHAN, YI-YANG

2014-01-01

16

The 5, 10 methylenetetrahydrofolate reductase C677T mutation and risk of fetal loss: a case series and review of the literature  

Microsoft Academic Search

BACKGROUND: The true relationship between methylenetetrahydrofolate reductase C677T homozygosity and risk of recurrent spontaneous abortion is unknown, and it is unclear if women with these mutations should be anticoagulated during pregnancy. OBJECTIVES: We report a series of 8 patients with this issue and review the current literature. METHODS: 8 patients (3 of whom were actively pregnant) were referred with histories

Ivy Altomare; Alan Adler; Louis M Aledort

2007-01-01

17

Neonatal and fetal methylenetetrahydrofolate reductase genetic polymorphisms: an examination of C677T and A1298C mutations.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) mutations are commonly associated with hyperhomocysteinemia, and, through their defects in homocysteine metabolism, they have been implicated as risk factors for neural tube defects and unexplained, recurrent embryo losses in early pregnancy. Folate sufficiency is thought to play an integral role in the phenotypic expression of MTHFR mutations. Samples of neonatal cord blood (n=119) and fetal tissue (n=161) were analyzed for MTHFR C677T and A1298C mutations to determine whether certain MTHFR genotype combinations were associated with decreased in utero viability. Mutation analysis revealed that all possible MTHFR genotype combinations were represented in the fetal group, demonstrating that 677T and 1298C alleles could occur in both cis and trans configurations. Combined 677CT/1298CC and 677TT/1298CC genotypes, which contain three and four mutant alleles, respectively, were not observed in the neonatal group (P=.0402). This suggests decreased viability among fetuses carrying these mutations and a possible selection disadvantage among fetuses with increased numbers of mutant MTHFR alleles. This is the first report that describes the existence of human MTHFR 677CT/1298CC and 677TT/1298CC genotypes and demonstrates their potential role in compromised fetal viability. PMID:10958762

Isotalo, P A; Wells, G A; Donnelly, J G

2000-10-01

18

Neonatal and Fetal Methylenetetrahydrofolate Reductase Genetic Polymorphisms: An Examination of C677T and A1298C Mutations  

PubMed Central

Methylenetetrahydrofolate reductase (MTHFR) mutations are commonly associated with hyperhomocysteinemia, and, through their defects in homocysteine metabolism, they have been implicated as risk factors for neural tube defects and unexplained, recurrent embryo losses in early pregnancy. Folate sufficiency is thought to play an integral role in the phenotypic expression of MTHFR mutations. Samples of neonatal cord blood (n=119) and fetal tissue (n=161) were analyzed for MTHFR C677T and A1298C mutations to determine whether certain MTHFR genotype combinations were associated with decreased in utero viability. Mutation analysis revealed that all possible MTHFR genotype combinations were represented in the fetal group, demonstrating that 677T and 1298C alleles could occur in both cis and trans configurations. Combined 677CT/1298CC and 677TT/1298CC genotypes, which contain three and four mutant alleles, respectively, were not observed in the neonatal group (P=.0402). This suggests decreased viability among fetuses carrying these mutations and a possible selection disadvantage among fetuses with increased numbers of mutant MTHFR alleles. This is the first report that describes the existence of human MTHFR 677CT/1298CC and 677TT/1298CC genotypes and demonstrates their potential role in compromised fetal viability. PMID:10958762

Isotalo, Phillip A.; Wells, George A.; Donnelly, James G.

2000-01-01

19

The Frequency of A1298C and C677T Polymorphisms of the Methylentetrahydrofolate Gene in Turkish Patients with Rheumatoid Arthritis: Relationship with Methotrexate Toxicity  

PubMed Central

The C677T and A1298C polymorphisms of methylenetatrahydrofolate reductase (MTHFR) gene are reported to have a relationship to methotrexate (MTX) metabolism, with conflicting results. The aim of this study was to determine the frequency of MTHFR C677 T and A1298C gene polymorphisms in a group of Turkish RA patients and evaluate its association with MTX toxicity. Sixty-four patients with RA and 31 control subjects with a mean age of 48.7 ±12.5 and 46.2 ± 13.4 years, were enrolled to the study. Demographic characteristics were obtained and MTX-related adverse effects were recorded in the patient group. The A1298C and C677T polymorphisms of the MTHFR gene were analyzed and the distribution of genotypes according side effects, were determined. The frequency of MTHFR C677T and A1298C polymorphisms were similar in the patient and control groups. Folic acid supplementation with a mean dose of 5mg folic acid/week, was present in all patients. Thirty-six of the 64 patients showed adverse effects to MTX treatment, and MTX had been discontinued in 12 (18.8%) patients due to side effects and/or inefficacy. MTHFR C677T and A1298C gene polymorphisms were found to be similar in patients with and without MTX-related adverse events. In conclusion, A1298C and C677T polymorphisms in the MTHFR gene, were not related with MTX-related toxicity in RA patients receiving folate supplementation. Further studies are needed to illuminate the polymorphisms in other enzymes that might be responsible from the MTX toxicity in patients suffering from RA. PMID:22046205

Ta?ba?, Özgür; Borman, P?nar; Gürhan Karabulut, Halil; Tükün, Ajlan; Yorganc?o?lu, Rezan

2011-01-01

20

Analysis of relation between C677T genotype in MTHFR gene and prostatic cancer in Iranian males.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) enzyme is one of the most important enzymes with a pivotal role in the folate metabolism and DNA synthesis pathways. Single nucleotide polymorphism (SNPs) in the coding gene has been related to many medical diseases as well as diverse malignancies including the prostate cancer which is the leading cause of the cancer deaths in men and one of the major public health problems. The goal of this study is to determine the relationship between the MTHFR C677T SNP and the prostate adenocarcinoma in Iranian males attending to the Labbafi-nezhad hospital in Tehran. In this Case-control unmatched study, 67 and 75 paraffinized tissue samples were taken out of the specimens diagnosed previously as the prostatic adenocarcinoma and nodular prostatic hyperplasia for the case and control groups respectively. MTHFR C677T genotyping was done by the use of multiplex ARMS-PCR and frequencies of the alleles were compared between the case and control groups as well as calculating the deviation from Hardy-Weinberg equilibrium and Odds Ratio for the "T" allele regarding the prostatic carcinoma. The observed rates in the control group were not too different from that of expected from Hardy-Weinberg equilibrium (P=0.407). Frequencies of the possible genotypes were as follows: CC, 43.28% vs. 42.67%; CT, 49.25% vs. 52% and CT, 7.46% vs. 5.33% in the case and control groups respectively (P=0.85). 1.37 times increased risk was found for the homozygote carriers of C677T variant (OR: 1.37, 95% CI: 0.33-5.6; P=0.653) which is however statistically not significant. No association has been evident between the MTHFR 677C>T polymorphism and the risk of prostatic carcinoma in this study confirming the findings of some of the previous attempts; however, (OR: 1.37, 95% CI: 0.33-5.6) implies a slight effect of the homozygote on the carcinogenesis. Thus larger studies especially with a greater number of the smaples are recommended. PMID:23275280

Fard-Esfahani, Pezhman; Mohammadi Torbati, Peyman; Hashemi, Zahra; Fayaz, Shima; Golkar, Majid

2012-01-01

21

Preponderance of methylenetetrahydrofolate reductase C677T homozygosity among leukemia patients intolerant to methotrexate  

Microsoft Academic Search

Background: Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, a common mutation of the gene encoding the enzyme that catalyzes reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate, a carbon donor in the metabolism of folate, determines a striking reduction in the enzyme activity in carriers of mutation at homozygous status. Patients and methods: We retrospectively analyzed the incidence of MTHFR C677T and the influence of

P. Chiusolo; G. Reddiconto; I. Casorelli; L. Laurenti; F. Sorà; L. Mele; L. Annino; G. Leone

2002-01-01

22

Spectrum of MTHFR gene SNPs C677T and A1298C: a study among 23 population groups of India.  

PubMed

Elevated homocysteine is a risk factor for many complex disorders. The role of methylenetetrahydrofolate reductase (MTHFR) gene in methylation of homocysteine makes it one of the most important candidate genes for these disorders. Considering the heterogeneity in its distribution in world populations, we screened MTHFR C677T and A1298C single nucleotide polymorphisms in a total of 23 Indian caste, tribal and religious population groups from five geographical regions of India and belonging to four major linguistic groups. The frequencies of MTHFR 677T and 1298C alleles were found to be 10.08 and 20.66%, respectively. MTHFR homozygous genotype 677TT was absent in eight population groups and homozygous 1298CC was absent in two population groups. 677T allele was found to be highest among north Indian populations with Indo-European tongue and 1298C was high among Dravidian-speaking tribes of east India and south India. The less common mutant haplotype 677T-1298C was observed among seven population groups and overall the frequency of this haplotype was 0.008, which is similar to that of African populations. cis configuration of 677T and 1298C was 0.94%. However, we could not find any individual with four mutant alleles which supports the earlier observation that presence of more than two mutant alleles may decrease the viability of foetus and possibly be a selective disadvantage in the population. PMID:22147263

Saraswathy, Kallur Nava; Asghar, Mohammad; Samtani, Ratika; Murry, Benrithung; Mondal, Prakash Ranjan; Ghosh, Pradeep Kumar; Sachdeva, Mohinder Pal

2012-04-01

23

Molecular analysis of factor V Leiden, factor V Hong Kong, factor II G20210A, methylenetetrahydrofolate reductase C677T, and A1298C mutations related to Turkish thrombosis patients.  

PubMed

Inherited gene disorders related to the hemostatic system have been documented as risk factors for thrombosis. The roles of factor V Hong Kong (FV Hong Kong), factor V Leiden (FV Leiden), factor II G20210A (FII G20210A), methylenetetrahydrofolate reductase (MTHFR) C677T, and MTHFR A1298C mutations in Turkish patients with thrombosis (270 patients) compared with healthy controls (114 subjects) were evaluated. Polymerase chain reaction-based restriction enzyme analysis was carried out to screen these mutations, and single-strand conformation analysis was established to identify variations using the primers selected for restriction enzyme analysis studies. As a result, a significant relationship was determined among FV Leiden, FII G20210A, and thrombosis. The FV Hong Kong mutation was observed in only 2 patients with pulmonary vein thrombosis who are FV Leiden/FV Hong Kong compound heterozygous for FV gene. MTHFR C677T and A1298C were equally distributed in the patient group compared with the control group. All named mutations were also identified with single-strand conformation analysis, but a new variant/polymorphism during studies was not found. Because some inherited abnormalities are associated with thromboembolic disorders, determining the mutations and gene-to-gene interactions in patients with thrombosis history has a great impact on diagnosis and treatment of these diseases. PMID:17911197

Dölek, Bilgen; Eraslan, Serpil; Ero?lu, Sevim; Kesim, Belgin Eroglu; Ulutin, Turgut; Yalçiner, Altan; Laleli, Yahya R; Gözükirmizi, Nermin

2007-10-01

24

MTHFR C677T polymorphisms are associated with aberrant methylation of the IGF-2 gene in transitional cell carcinoma of the bladder  

PubMed Central

The purpose of this study was to determine the relationship between methylation status of the insulin-like growth factor 2 (IGF-2) gene and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in bladder transitional cell carcinoma tissues in a Chinese population. The polymorphisms of the folate metabolism enzyme gene MTHFR were studied by restrictive fragment length polymorphism (RFLP). PCR-based methods of DNA methylation analysis were used to detect the CpG island methylation status of the IGF-2 gene. The association between the methylation status of the IGF-2 gene and clinical characteristics, as well as MTHFR C677T polymorphisms, was analyzed. Aberrant hypomethylation of the IGF-2 gene was found in 68.3% bladder cancer tissues and 12.4% normal bladder tissues, respectively, while hypomethylation was not detected in almost all normal bladder tissues. The hypomethylation rate of the IGF-2 gene in cancer tissues was significantly higher in patients with lymph node metastasis than in those without lymph node metastasis (46.3% vs 17.2%, P = 0.018). No association was found between aberrant DNA methylation and selected factors including sex, age, tobacco smoking, alcohol consumption and green tea consumption. After adjusting for potential confounding variables the variant allele of MTHFR C677T was found to be associated with hypomethylation of the IGF-2 gene. Compared with wildtype CC, the odds ratio was 4.33 (95% CI=1.06-10.59) for CT and 4.95 (95% CI=1.18-12.74) for TT. MTHFR 677 CC and CT genotypes might be one of the reasons that cause abnormal hypomethylation of the IGF-2 gene, and the aberrant CpG island hypomethylation of the IGF-2 gene may contribute to the genesis and progression of bladder transitional cell carcinoma. PMID:23554734

Cheng, Huan; Deng, Zhonglei; Wang, Zengjun; Zhang, Wei; Su, Jiantang

2012-01-01

25

MTHFR C677T polymorphisms are associated with aberrant methylation of the IGF-2 gene in transitional cell carcinoma of the bladder.  

PubMed

The purpose of this study was to determine the relationship between methylation status of the insulin-like growth factor 2 (IGF-2) gene and methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms in bladder transitional cell carcinoma tissues in a Chinese population. The polymorphisms of the folate metabolism enzyme gene MTHFR were studied by restrictive fragment length polymorphism (RFLP). PCR-based methods of DNA methylation analysis were used to detect the CpG island methylation status of the IGF-2 gene. The association between the methylation status of the IGF-2 gene and clinical characteristics, as well as MTHFR C677T polymorphisms, was analyzed. Aberrant hypomethylation of the IGF-2 gene was found in 68.3% bladder cancer tissues and 12.4% normal bladder tissues, respectively, while hypomethylation was not detected in almost all normal bladder tissues. The hypomethylation rate of the IGF-2 gene in cancer tissues was significantly higher in patients with lymph node metastasis than in those without lymph node metastasis (46.3% vs 17.2%, P = 0.018). No association was found between aberrant DNA methylation and selected factors including sex, age, tobacco smoking, alcohol consumption and green tea consumption. After adjusting for potential confounding variables the variant allele of MTHFR C677T was found to be associated with hypomethylation of the IGF-2 gene. Compared with wildtype CC, the odds ratio was 4.33 (95% CI=1.06-10.59) for CT and 4.95 (95% CI=1.18-12.74) for TT. MTHFR 677 CC and CT genotypes might be one of the reasons that cause abnormal hypomethylation of the IGF-2 gene, and the aberrant CpG island hypomethylation of the IGF-2 gene may contribute to the genesis and progression of bladder transitional cell carcinoma. PMID:23554734

Cheng, Huan; Deng, Zhonglei; Wang, Zengjun; Zhang, Wei; Su, Jiantang

2012-03-01

26

The Prevalence of Factor V Leiden (G1691A) and Methylenetetrahydrofolate Reductase C677T Mutations in Sickle Cell Disease in Western India.  

PubMed

The prevalence of the Factor V Leiden (FVL; G1691A) mutation and the methylenetetrahydrofolate reductase (MTHFR; C677T) mutation was determined in 180 patients with sickle cell (SS) disease (126 sickle homozygous and 54 sickle ?-thalassaemia-age 1-47 years) and in 130 healthy controls. The FVL mutation in the heterozygous state was present in only 3 patients with SS disease and was absent in the controls. Genotyping of MTHFR 677C > T revealed increased frequency of the C allele than the T allele in patients as well as in controls. This suggests that these genetic markers may not be major risk factors for a hypercoagulable state in Indian patients with SS disease. PMID:23869056

Kangne, Harshada K; Jijina, Farah F; Italia, Yazdi M; Jain, Dipti L; Nadkarni, Anita H; Ghosh, Kanjaksha K; Colah, Roshan B

2015-03-01

27

Methylenetetrahydrofolate reductase gene C677T, A1298C polymorphisms and pre-eclampsia risk: a meta-analysis.  

PubMed

To determine whether methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms are associated with pre-eclampsia susceptibility. Literature searches of the Pubmed, Embase, BIOSIS Previews and Web of Science were conducted to identify all eligible articles up to January 18th, 2013. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) of five genetic models were calculated by fixed-effects or random-effects model. Publication bias, subgroup analysis, meta-regression and sensitivity analysis were also performed. A number of 49 studies including 51 samples consisted of 18,009 subjects (6,238 patients and 11,771 controls) were finally included. MTHFR C677T allele (TT or CT) carriers were 1.12 times more likely to develop pre-eclampsia (95% CI 1.04-1.21) compared with 677CC homozygous individuals. Similar results were obtained under other genetic models. Restricted to severe pre-eclampsia, there was an increased risk for 677TT homozygotes compared with 677CC homozygotes (OR 1.43; 95% CI 1.12-1.83). Subgroup analysis revealed a significant positive association between the C677T polymorphism (TT or CT) and pre-eclampsia in Asians (OR 1.41; 95% CI 1.11-1.79) and white population (OR 1.14; 95% CI 1.03-1.25). Meta-regression showed that study population, blinded genotyping, matching of cases and controls were not substantial sources of heterogeneity. For the MTHFR A1298C, ORs for all genetic models yielded a null association. This meta-analysis suggests that the MTHFR 677T allele might be associated with increased pre-eclampsia risk in Asian and white ethnicity and the subgroup of severe pre-eclampsia, while no association is observed between the MTHFR A1298C polymorphism and pre-eclampsia. PMID:24898880

Li, Xing; Luo, Ya L; Zhang, Qiong H; Mao, Chen; Wang, Xi W; Liu, Shan; Chen, Qing

2014-08-01

28

Investigation of MTHFR C677T gene polymorphism, biochemical and clinical parameters in Turkish migraine patients: association with allodynia and fatigue.  

PubMed

We investigated whether there is any relationship between biochemical and clinical parameters of migraine and methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism, associated with the migraine subtypes, symptoms, and gender. A total of 150 migraine patients with and without aura (MA and MO) and 107 non-sufferers were included in the study. Biochemical and clinical parameters were measured and genetic analysis was performed. The MTFHR C677T genotype was significantly higher in the migraine group (p = 0.000). The CT genotype frequency of individuals with a family history of migraine was significantly higher (p = 0.025). This genotype frequency was higher in patients who suffer from compression, allodynia, fatigue, and sleeplessness (p = 0.027, 0.023, 0.006, and 0.05, respectively). Homocysteine and total cholesterol levels were significantly higher in the migraine group than the control group (p = 0.007 and 0.010, respectively). However, the other biochemical and clinical parameters did not differ from each other (p > 0.05), with only attack frequency being significantly higher in the MO group (p = 0.005). While the folate and HDL levels were significantly higher in females (p = 0.001 and 0.000, respectively), the homocysteine and triglyceride levels were significantly higher in males (p = 0.000 for each one). BMIs were significantly lower in the control than the migraine group (p = 0.021); however, an association between the C677T variant and BMI was not found (p = 0.787) in the migraine group. An association between the MTHFR C667T polymorphism and migraine susceptibility was found. Additional studies including genetic, clinic, and biochemical parameters should be conducted to better understand the disease. PMID:23975093

Bahadir, Anzel; Eroz, Recep; Dikici, Suber

2013-11-01

29

Is the C677T polymorphism in methylenetetrahydrofolate reductase gene or plasma homocysteine a risk factor for diabetic peripheral neuropathy in Chinese individuals??  

PubMed Central

The present study enrolled 251 diabetic patients, including 101 with neuropathy and 150 without neuropathy. Of the 150 patients, 100 had no complications, such as retinopathy, nephropathy, or neuropathy. Polymerase chain reaction-restriction fragment length polymorphism analysis was used to identify methylenetetrahydrofolate reductase gene variants. Plasma homocysteine levels were also measured. Homocysteine levels and the frequency of hyperhomocysteinemia were significantly higher in patients with diabetic peripheral neuropathy compared with diabetic patients without neuropathy (P < 0.05). In logistic regression analysis with neuropathy as the dependent variable, the frequency of C677T in methylenetetrahydrofolate reductase was significantly higher in patients with diabetic peripheral neuropathy compared with patients without diabetic complications. Homocysteine levels were significantly higher in patients with diabetic peripheral neuropathy carrying the 677T allele and low folic acid levels. In conclusion, hyperhomocysteinemia is an independent risk factor for diabetic neuropathy in Chinese patients with diabetes. The C677T polymorphism in methylenetetrahydrofolate reductase and low folic acid levels may be risk factors for diabetic peripheral neuropathy in Chinese patients with diabetes.

Wang, Hongli; Fan, Dongsheng; Hong, Tianpei

2012-01-01

30

Common folate gene variant, MTHFR C677T, is associated with brain structure in two independent cohorts of people with mild cognitive impairment.  

PubMed

A commonly carried C677T polymorphism in a folate-related gene, MTHFR, is associated with higher plasma homocysteine, a well-known mediator of neuronal damage and brain atrophy. As homocysteine promotes brain atrophy, we set out to discover whether people carrying the C677T MTHFR polymorphism which increases homocysteine, might also show systematic differences in brain structure. Using tensor-based morphometry, we tested this association in 359 elderly Caucasian subjects with mild cognitive impairment (MCI) (mean age: 75 ± 7.1 years) scanned with brain MRI and genotyped as part of Alzheimer's Disease Neuroimaging Initiative. We carried out a replication study in an independent, non-overlapping sample of 51 elderly Caucasian subjects with MCI (mean age: 76 ± 5.5 years), scanned with brain MRI and genotyped for MTHFR, as part of the Cardiovascular Health Study. At each voxel in the brain, we tested to see where regional volume differences were associated with carrying one or more MTHFR 'T' alleles. In ADNI subjects, carriers of the MTHFR risk allele had detectable brain volume deficits, in the white matter, of up to 2-8% per risk T allele locally at baseline and showed accelerated brain atrophy of 0.5-1.5% per T allele at 1 year follow-up, after adjusting for age and sex. We replicated these brain volume deficits of up to 5-12% per MTHFR T allele in the independent cohort of CHS subjects. As expected, the associations weakened after controlling for homocysteine levels, which the risk gene affects. The MTHFR risk variant may thus promote brain atrophy by elevating homocysteine levels. This study aims to investigate the spatially detailed effects of this MTHFR polymorphism on brain structure in 3D, pointing to a causal pathway that may promote homocysteine-mediated brain atrophy in elderly people with MCI. PMID:24179750

Rajagopalan, Priya; Jahanshad, Neda; Stein, Jason L; Hua, Xue; Madsen, Sarah K; Kohannim, Omid; Hibar, Derrek P; Toga, Arthur W; Jack, Clifford R; Saykin, Andrew J; Green, Robert C; Weiner, Michael W; Bis, Joshua C; Kuller, Lewis H; Riverol, Mario; Becker, James T; Lopez, Oscar L; Thompson, Paul M

2012-01-01

31

Role of C677T and A1298C MTHFR, A2756G MTR and -786 C/T eNOS Gene Polymorphisms in Atrial Fibrillation Susceptibility  

PubMed Central

Background Hyperhomocysteinemia has been suggested to play a role in the NonValvular Atrial Fibrillation (NVAF) pathogenesis. Polymorphisms in genes coding for homocysteine (Hcy) metabolism enzymes may be associated with hyperhomocysteinemia and NVAF. Methodologies 456 NVAF patients and 912 matched controls were genotyped by an electronic microchip technology for C677T and A1298C MTHFR, A2756G MTR, and -786C/T eNOS gene polymorphisms. Hcy was determined by an immunoassay method. Principal Findings The genotype distribution of the four polymorphisms as well as genotype combinations did not differ in patients and controls. Hcy was higher in patients than in controls (15.2, 95%CI 14.7–15.7 vs 11.3, 95%CI 11.0–11.6 µmol/L; p<0.0001). In both populations, a genotype-phenotype association (p<0.0001) between Hcy and C677T MTHFR polymorphism was observed; in controls a significant (p?=?0.029) association between tHcy and ?786C/T eNOS polymorphism was also observed. At the multivariate analysis the NVAF risk significantly increased in the upper quartiles of Hcy compared to the lowest: OR from 2.8 (1.68–4.54 95%CI) in Q2 to 12.9 (7.96–21.06 95%CI) in Q4. Conclusions Our data demonstrated the four polymorphisms, although able, at least in part, to affect Hcy, were not associated with an increased risk of NVAF per se or in combination. PMID:17551576

Giusti, Betti; Gori, Anna Maria; Marcucci, Rossella; Sestini, Ilaria; Saracini, Claudia; Sticchi, Elena; Gensini, Francesca; Fatini, Cinzia; Abbate, Rosanna; Gensini, Gian Franco

2007-01-01

32

MTHFR Gene variants C677T, A1298C and association with Down syndrome: A Case-control study from South India  

PubMed Central

BACKGROUND: The 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and low folate levels are associated with inhibition of DNA methyltransferase and consequently DNA hypomethylation. The expanding spectrum of common conditions linked with MTHFR polymorphisms includes certain adverse birth outcome, pregnancy complications, cancers, adult cardiovascular diseases and psychiatric disorders, with several of these associations remaining still controversial. Trisomy 21 or Down syndrome (DS) is the most common genetic cause of mental retardation. It stems predominantly from the failure of chromosome 21 to segregate normally during meiosis. Despite substantial research, the molecular mechanisms underlying non-disjunction leading to trisomy 21 are poorly understood. MATERIALS AND METHODS: Two common variants C677T and A1298C of the MTHFR gene were screened in 36 parents with DS children and 60 healthy couples from Tamil Nadu and Karnataka. The MTHFR genotypes were studied by RFLP analysis of PCR-amplified products and confirmed by sequencing. RESULTS: The CT genotype was seen in three each (8.3%) of case mothers and fathers. One case father showed TT genotype. All the control individuals exhibited the wild type CC genotype. A similar frequency for the uncommon allele C of the second polymorphism was recorded in case mothers (0.35) and fathers (0.37) in comparison with the control mothers (0.39) and fathers (0.37). CONCLUSION: This first report on MTHFR C677T and A1298C polymorphisms in trisomy 21 parents from south Indian population revealed that MTHFR 677CT polymorphism was associated with a risk for Down syndrome. PMID:20680153

Cyril, Cyrus; Rai, Padmalatha; Chandra, N.; Gopinath, P. M.; Satyamoorthy, K.

2009-01-01

33

Associations of MTHFR C677T and MTRR A66G gene polymorphisms with metabolic syndrome: a case-control study in Northern China.  

PubMed

Prior evidence indicates that homocysteine plays a role in the development of metabolic syndrome (MetS). Methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms are common genetic determinants of homocysteine levels. To investigate the associations of the MTHFR C677T and MTRR A66G polymorphisms with MetS, 692 Chinese Han subjects with MetS and 878 controls were recruited. The component traits of MetS and the MTHFR C677T and MTRR A66G genotypes were determined. A significant association was observed between the MTHFR 677T allele and increased risk of MetS, high fasting blood glucose, high waist circumference, and increasing number of MetS components. The MTRR A66G polymorphism was associated with an increased risk of MetS when combined with the MTHFR 677TT genotype, although there was no association found between MetS and MTRR A66G alone. Furthermore, the MTRR 66GG genotype was associated with high fasting blood glucose and triglycerides. Our data suggest that the MTHFR 677T allele may contribute to an increased risk of MetS in the northern Chinese Han population. The MTRR A66G polymorphism is not associated with MetS. However, it may exacerbate the effect of the MTHFR C677T variant alone. Further large prospective population-based studies are required to confirm our findings. PMID:25429430

Yang, Boyi; Fan, Shujun; Zhi, Xueyuan; Wang, Da; Li, Yongfang; Wang, Yinuo; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

2014-01-01

34

Associations of MTHFR C677T and MTRR A66G Gene Polymorphisms with Metabolic Syndrome: A Case-Control Study in Northern China  

PubMed Central

Prior evidence indicates that homocysteine plays a role in the development of metabolic syndrome (MetS). Methylenetetrahydrofolate reductase (MTHFR) C677T and methionine synthase reductase (MTRR) A66G polymorphisms are common genetic determinants of homocysteine levels. To investigate the associations of the MTHFR C677T and MTRR A66G polymorphisms with MetS, 692 Chinese Han subjects with MetS and 878 controls were recruited. The component traits of MetS and the MTHFR C677T and MTRR A66G genotypes were determined. A significant association was observed between the MTHFR 677T allele and increased risk of MetS, high fasting blood glucose, high waist circumference, and increasing number of MetS components. The MTRR A66G polymorphism was associated with an increased risk of MetS when combined with the MTHFR 677TT genotype, although there was no association found between MetS and MTRR A66G alone. Furthermore, the MTRR 66GG genotype was associated with high fasting blood glucose and triglycerides. Our data suggest that the MTHFR 677T allele may contribute to an increased risk of MetS in the northern Chinese Han population. The MTRR A66G polymorphism is not associated with MetS. However, it may exacerbate the effect of the MTHFR C677T variant alone. Further large prospective population-based studies are required to confirm our findings. PMID:25429430

Yang, Boyi; Fan, Shujun; Zhi, Xueyuan; Wang, Da; Li, Yongfang; Wang, Yinuo; Wang, Yanxun; Wei, Jian; Zheng, Quanmei; Sun, Guifan

2014-01-01

35

Geographical Distribution of MTHFR C677T, A1298C and MTRR A66G Gene Polymorphisms in China: Findings from 15357 Adults of Han Nationality  

PubMed Central

Background Methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C and methionine synthase reductase (MTRR) A66G polymorphisms are important genetic determinants for homocysteine (Hcy) levels, and are associated with several disorders. These polymorphisms are heterogeneously distributed worldwide. Our objective was to explore the geographical distributions of these polymorphisms in China. Methodologies 15357 healthy adults were recruited from 10 regions. Buccal samples were collected and genomic DNA was isolated. Genotyping was performed using the fluorogenic 5?-nuclease assay. Principal Findings The prevalence of the three polymorphisms among different populations from China varied significantly and showed apparent geographical gradients. For MTHFR C677T, the frequencies of the 677T allele and the 677TT genotype were significantly higher among northern populations and ranged from the lowest values (24.0% and 6.4%, respectively) in Hainan (southern) to the highest values (63.1% and 40.8%, respectively) in Shandong (northern). For MTHFR A1298C, the 1298C allele and the 1298CC genotype frequencies were significantly higher among southern populations and increased from low values (13.1% and 1.4%, respectively) in Shandong to high values (25.7% and 6.7%, respectively) in Hainan. For A66G, the 66G allele and the 66GG genotype frequencies increased from lower values (23.7% and 5.4%, respectively) in Shandong to higher values (29.2% and 8.6%, respectively) in Hainan. The overall frequency of the 677T allele, 677TT genotype, 1298C allele, 1298CC genotype, 66G allele and 66GG genotype in the Chinese Han population was 45.2%, 23.2%, 18.6%, 3.9%, 25.7%, and 6.6%, respectively. No gender differences were found in the prevalence of both the MTHFR C677T and MTRR A66G polymorphisms. Conclusions This study indicates that there are marked geographical variations in the prevalence of the three polymorphisms among Chinese Han populations. Our baseline data may be useful for future researches in related fields. PMID:23472119

Yang, Boyi; Liu, Yuyan; Li, Yongfang; Fan, Shujun; Zhi, Xueyuan; Lu, Xiangxiang; Wang, Da; Zheng, Quanmei; Wang, Yinuo; Wang, Yanxun; Sun, Guifan

2013-01-01

36

Genetic susceptibility of methylenetetrahydrofolate reductase (MTHFR) gene C677T, A1298C, and G1793A polymorphisms with risk for bladder transitional cell carcinoma in men.  

PubMed

We performed a case-control study of 158 bladder transitional cell carcinoma (TCC) cases and 316 controls to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T, A1298G, and G1793A polymorphisms and bladder cancer susceptibility by polymerase chain reaction restriction fragment length polymorphism (PCR-RLFP) technique. The controls were frequency-matched to the cases by age (± 5 years), ethnicity, and smoking status. We also measured serum levels of total homocysteine (tHcy), folate, and vitamin B12. It was found that the 1298AC (odds ratio, OR = 3.74; 95% confidence interval, CI = 2.34-5.47; P = 0.001) and 1298CC (OR = 3.46, 95% CI = 2.37-5.52; P = 0.001) genotypes of MTHFR A1298C were significantly associated with increased risk of bladder TCC. The MTHFR C677T and G1793A polymorphisms were not associated with bladder TCC. After stratification for grade and stage, we observed that the 677TT (OR = 4.47, 95% CI = 2.74-6.72; P = 0.001) and MTHFR 1298CC (OR = 4.78, 95% CI = 2.82-6.89; P = 0.001) genotypes of MTHFR were associated with increased risk of muscle-invasive bladder TCC. We also found that the MTHFR 677CT+1298AA genotypes were associated with an approximately 70% reduction in risk of bladder cancer (OR = 0.31; 95% CI = 0.15-0.68) compared to the combined referent genotype. There were 8 haplotypes and 16 haplotype genotypes based on these three variants. When we used the haplotypes and assumed that the 677T, 1298C, and 1793G alleles were risk alleles, the adjusted odds ratios increased as the number of risk alleles increased: 1.00 for 0-1 variant, 1.88 (1.4-2.7) for any two risk alleles and 2.07 (1.6-2.8) for any three risk alleles. Serum tHcy levels were significantly higher in carriers of the 677T, 1298C, and 1793G alleles compared to noncarriers (all P < 0.01). There was no significant correlation between serum levels of tHcy and folate and bladder cancer risk. Further studies in larger samples size and different ethnicity are required to confirm our findings. PMID:21046286

Safarinejad, Mohammad Reza; Shafiei, Nayyer; Safarinejad, Shiva

2011-12-01

37

Methylenetetrahydrofolate reductase gene germ-line C677T and A1298C SNPs are associated with colorectal cancer risk in the Turkish population.  

PubMed

Colorectal cancer (CRC) is the third most common cause of death due to cancer in the worldwide and the incidence is also increasing in Turkey. Our present aim was to investigate any association between germ-line methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and CRC risk in Turkey. A total of 86 CRC cases and 212 control individuals of the same ethnicity were included in the current study. Peripheral blood-DNA samples were used for genotyping by StripAssay technique, based on the reverse- hybridization principle and real-time PCR methods. Results were compared in Pearson Chi-square and multiple logistic regression models. The MTHFR 677TT (homozygous) genotype was found in 20.9% and the T allele frequency 4.2-fold increased in CRC when compared with the control group.The second SNP MTHFR 1298CC (homozygous) genotype was found in 14.0% and the C allele frequency 1.4-fold elevated in the CRC group. The current data suggest strong associations between both SNPs of germ-line MTHFR 677 C>T and 1298 A>C genotypes and CRC susceptibility in the Turkish population. Now the results need to be confirmed with a larger sample size. PMID:25292054

Ozen, Filiz; Sen, Metin; Ozdemir, Ozturk

2014-01-01

38

Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphism in Iranian Women With Idiopathic Recurrent Pregnancy Losses  

PubMed Central

Background: Recurrent pregnancy loss (RPL) is a serious problem for pregnancy. There is evidence that vascular complications play a principal role in RPL. Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. Polymorphisms (C677T, A1298C) of MTHFR gene are associated with decreased MTHFR activity. Objectives: The aim of this study was to determine the association between MTHFR polymorphisms (C677T and A1298C) and recurrent pregnancy loss (RPL) in Iranian women. Materials and Methods: In this case-control study, blood samples were obtained from patients who had three or more consecutive pregnancy losses before the 22nd week of pregnancy (n = 204). The control group consisted of 116 age-matched women with at least one alive child and without any history of pregnancy loss or other gestational complications (n = 116). Following DNA extraction, samples were tested for MTHFR C677T and A1298C polymorphisms using the reverse hybridization method. Results: The prevalence of 677TT mutation was 8.8% (18/204) in the patient group and 8.6% (10/116) in the control group (P = 0.434). The prevalence of 1298CC mutation was 12.3 % (25/204) in the patient group and 8% (9/116) in the control group (P = 0.155). Investigation of the distributions of various genotypes of MTHFR C677T and A1298C did not indicate a significant difference between patients with RPL and healthy control subjects. Conclusions: The results suggest that MTHFR mutations might not be associated with RPL in the examined population. PMID:25237572

Yousefian, Elham; Kardi, Mohammad Taghi; Allahveisi, Azra

2014-01-01

39

Association of methylenetetrahydrofolate reductase (A1298C and C677T) polymorphisms with retinal vein occlusion in Tunisian patients.  

PubMed

The role of two polymorphisms C677T and A1298C of the methylenetetrahydrofolate reductase (MTHFR) gene in the etiology of retinal vein occlusion (RVO) has not been adequately clarified. The aim of this study was to examine the prevalence of these polymorphisms among RVO Tunisian patients with and without systemic risk factors. Seventy-two patients with retinal vein occlusion (RVO) were studied. The control group included140 people matched for age, sex, and risk factors. Participants in the study were genotyped for the MTHFR C677T and A1298C polymorphisms. The genotyping was performed by PCR-RFLP. No significant differences were found in the frequencies of the three genotypes (AA, AC, CC) of the MTHFR A1298C polymorphism between RVO patients and healthy controls. However, the prevalence of the group of mutated genotypes (AC+CC) of the missense variant MTHFR A1298C was significantly different between patients and controls (16.67% vs. 6.42%, p=.01). Additionally, the frequency of the CT genotype as well as the group of combined mutated genotypes (CT+TT) for the C677T variant was significantly higher among RVO patients compared with controls (p<10(-3), p<10(-3)). This suggests an association between this polymorphism and RVO. Large study populations would be required to understand more completely the contribution of these markers in the risk of RVO. PMID:24440586

Mrad, Meriem; Wathek, Cheima; Saleh, Mekki Ben; Baatour, Makrem; Rannen, Riadh; Lamine, Khaled; Gabsi, Salem; Gritli, Nasreddine; Fekih-Mrissa, Najiba

2014-04-01

40

Effects of the MTHFR C677T polymorphism on prostate specific antigen and prostate cancer.  

PubMed

Prostate cancer is the most common malignancy and the second leading cause of cancer related deaths among men in many countries. Serum levels of prostate-spesific antigen (PSA) have attracted attention for prediction purposes. The methylenetetrahydrofolate reductase (MTHFR) gene play a critical role in cancer development, but its potential impact on prostate cancer has not been well studied. The C677T variant lies in exon 4 at the folate binding site of the MTHFR gene and results in substitution of an alanine by a valine residue. The present study was carried out 55 cases with prostate cancer and 50 healthy men. Polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP), and agarose gel electrophoresis techniques were employed to determine MTHFR C677T mutation. The frequencies of the CT genotype (p= 0.025) and T allele (p= 0.023) was found to be higher in control subjects when compared with patients group. No statistical difference was found between the alleles of MTHFR and PSA levels after (PSA-BT)/ before (PSA-AT) antiandrogen treatment or tumor stages. We suggest that the heterozygote CT genotype and the 677T allele of the MTHFR polymorphism might be associated with an decreased prostate cancer risk. PMID:22296369

Küçükhüseyin, Özlem; Kurnaz, Özlem; Akadam-Teker, A Basak; Narter, Fehmi; Y?lmaz-Aydo?an, Hülya; ?sbir, Turgay

2011-01-01

41

Association between Hcy levels and the CBS844ins68 and MTHFR C677T polymorphisms with essential hypertension  

PubMed Central

The aim of the present study was to investigate the association between the homocysteine (Hcy) levels and polymorphisms of the CBS844ins68 and MTHFR C677T genes in essential hypertension (EH). The effects of the MTHFR C677T and CBS844ins68 haploid genotypes and the combined genotypes on EH and levels of Hcy were further explored. The polymorphisms of CBS844ins68 and MTHFR C677T genes in 200 EH and 200 normal tensive (NT) patients were detected using polymerase chain reaction-restriction fragment length polymorphism and analysis of the distribution of genotypes. An automated biochemical analyzer was used to measure the plasma Hcy levels and the clinical biochemistry data. The plasma Hcy levels in EH were significantly higher than those of the NT group (P<0.05). There were no significant differences (P>0.05) between males and females. Two genotypes, deletion/deletion (DD) and deletion/insertion (DI), of the CBS844ins68 polymorphism were found in two groups with no clear differences in two genotypes and allele frequency distribution (P>0.05). There were significant differences in the three genotype frequencies (?2=6.658, ?2=4.410, P<0.05) for MTHFR C677T locus genotypes CC, CT and TT. The Hcy levels in genotypes DD and DI had no significant differences (P>0.05) and the CT and TT types were significantly higher compared to the CC genotype (P<0.05). The CC/DD combined genotype in the two groups was significantly different (P<0.05), and the odds ratio (OR), 0.569 showed that the CC/DD genotype may be a protective factor of hypertension. In the two groups, the Hcy levels for combined genotypes CC/DD, CT/DD, TT/DD and TT/DI were significantly different (P<0.05). The SHEsis software analysis linkage disequilibrium coefficient=0.216, indicates that there is probably a weak linkage for MTHFR C677T and CBS844ins68. Haplotype analysis suggested that the C-D haplotype was negatively correlated with EH (OR, 0.727) and that there was a positive correlation between T-D haplotype and EH (OR, 1.376). MTHFR C677T and CBS844ins68 polymorphisms were present in the populations studied and the CBS844ins68 homozygous mutation was not present. Therefore, there is a correlation between the polymorphisms of the MTHFR C677T gene and EH, and allele T may be one of the predisposing factors. MTHFR C677T and CBS844ins68 may exist with a certain linkage and the T-D haplotype may be a risk factor for EH. PMID:25279160

CAI, WEIJUAN; YIN, LIANG; YANG, FANG; ZHANG, LEI; CHENG, JIANG

2014-01-01

42

Association of the MTHFR C677T polymorphism with primary brain tumor risk.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) gene plays key roles not only in folate metabolism but also in carcinogenesis. The single nucleotide polymorphism MTHFR C677T has been indicated in the development of various tumors. The effect of the MTHFR C677T polymorphism on brain tumors remains poorly understood. We performed the present meta-analysis and aimed to provide a better understanding of the pathogenesis of brain tumors. A literature search of the PubMed, Embase, Web of Science, and Wanfang databases was carried out for potential relevant publications. We calculated the pooled odds ratio (OR) with corresponding 95% confidence interval (95% CI) to assess the association of MTHFR C677T with the susceptibility to brain tumors. We also performed stratified analysis and sensitivity analysis to further estimate the genetic association. All statistical analyses were conducted by the use of STATA 11.0 (STATA Corporation, College Station, TX, USA). Eight case-control studies involving a total of 3,059 cases and 3,324 controls were retrieved according to the inclusion criteria. The overall ORs suggested that the MTHFR C677T variant can exert a risk effect on brain tumor development under the following contrast models (OR(TC vs. CC) = 1.14, 95% CI 1.02-1.27, P OR = 0.018; OR(TT + TC vs. CC)= 1.23, 95% CI 1.01-1.51, P(OR) = 0.043). No significant correlation was identified among the Caucasians, but not among the Asians. In addition, the TC genotype carriers were more susceptible to meningioma when compared with the CC genotype carriers (OR(TC vs. CC) = 1.38, 95% CI 1.15-1.65, P(OR) < 0.001). The MTHFR C677T polymorphism seemed to exert no effect on glioma risk. The current meta-analysis firstly provides evidence that the MTHFR C677T polymorphism may modify the risk for brain tumors, particularly meningioma. The role of the MTHFR C677T variant in brain tumor pathogenesis across diverse ethnicities needs further elucidation by more future studies with large sample size. PMID:23846816

Xu, Chen; Yuan, Lutao; Tian, Hengli; Cao, Heli; Chen, Shiwen

2013-12-01

43

Prevalence of MTHFR C677T single nucleotide polymorphism in genetically isolated populations in Jordan.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) C677T single nucleotide polymorphism is a major inherited risk factor of venous thromboembolism. We sought to determine its prevalence in genetically isolated populations of Chechens and Circassians in Jordan. The MTHFR C677T mutation was analyzed from blood samples taken from 120 random unrelated Chechens and 72 Circassians. The prevalence of the MTHFR mutation in the Chechen population was 27.5% (allele frequency 15%); the prevalence among the Circassians was 50% (allele frequency 29.2%). The prevalence in the Chechen population is similar to that in Jordan and other world populations, but it is higher in the Circassian population. This study will contribute to understanding the interaction between genetic and environmental risk factors underlying thrombosis and will be useful in deciding which genetic variants should be tested in a clinical genetic testing service. PMID:23749065

Dajani, Rana; Fathallah, Raja; Arafat, Ala; AbdulQader, Mohammed Emad; Hakooz, Nancy; Al-Motassem, Yousef; El-Khateeb, Mohammad

2013-10-01

44

Association between factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase C677T mutations and events of the arterial circulatory system: a meta-analysis of published studies  

Microsoft Academic Search

BackgroundThe association between the inherited gene mutations of factor V, prothrombin, and homocysteine metabolism and venous thromboembolic events is accepted widely; however, their influence on the arterial circulatory system remains controversial.

Robert J Kim; Richard C Becker

2003-01-01

45

Prevalence of MTHFR C677T Polymorphism in North Indian Mothers Having Babies with Trisomy 21 Down Syndrome  

ERIC Educational Resources Information Center

Recent studies have evaluated possible links between polymorphisms in maternal folate metabolism genes and Down syndrome. Some of these studies show a significantly increased prevalence of the C677T polymorphism of the 5,10-methylene tetrahydrofolate reductase (NADPH) gene (MTHFR) among mothers who have had babies with Down syndrome. This study…

Kohli, Utkarsh; Arora, Sadhna; Kabra, Madhulika; Ramakrishnan, Lakshmy; Gulati, Sheffali; Pandey, Ravindra

2008-01-01

46

Response of serum and red blood cell folate concentrations to folic acid supplementation depends on methylenetetrahydrofolate reductase C677T genotype: Results from a crossover trial  

PubMed Central

Scope By increasing blood folate concentrations, folic acid supplementation reduces risk for neural tube defect-affected pregnancies, and lowers homocysteine concentrations. We assessed response of red blood cell (RBC) and serum folate to folic acid supplementation, and examined association of response with the genetic polymorphism C677T of the methylenetetrahydrofolate NAD(P)H (MTHFR) gene. Methods and Results Randomized, controlled, crossover trial with two folic acid supplement treatment periods and a 30-week washout period. The primary outcome is blood folate (serum and RBC) concentrations. Volunteers (n=142) aged 18-69 were randomized to two of three doses (0, 200, and 400 ?g) of folic acid for twelve weeks. Serum folate response depended on treatment period with significant responses to 200 ?g seen only in the second treatment periods (4.4 ng/mL or 3.4 ng/mL). Additionally, serum folate increased as folic acid dose increased to 400 ?g (p< 0.01) and response was greater after the washout period (8.7 ng/mL), than after a 6-week run-in (2.3 ng/mL). The differential change attributable to a daily supplement of 400 ?g compared to 200 ?g was 96.8 ng/mL; while the change attributable to 400 ?g compared to 0 ?g was 121.4. Increases in RBC folate concentrations with 400 ?g occurred within MTHFR gene mutation (C677T); and in the African American group. Conclusions Serum folate concentration is responsive to modest increases in folic acid intake. Red blood cell folate increases only with higher additional doses of folic acid supplementation, and this is true for each MTHFR C677T genotype. PMID:23456769

Anderson, Cheryl A.M.; Beresford, Shirley A. A.; McLerran, Dale; Lampe, Johanna W.; Deeb, Samir; Feng, Ziding; Motulsky, Arno G.

2013-01-01

47

Status of vitamin B-12 and B-6 but not of folate, homocysteine and the methylenetetrahydrofolate reductase C677T polymorphism are associated with impaired cognition and depression in adults  

Technology Transfer Automated Retrieval System (TEKTRAN)

The C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene differs in frequency in different ethnic groups which have differing prevalence of age-related cognitive impairments. We used a battery of neuropsychological tests to examine association of the MTHFR C677T polymorphism w...

48

A common mutation A1298C in human methylenetetrahydrofolate reductase gene: association with plasma total homocysteine and folate concentrations.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is one of the main regulatory enzymes of homocysteine metabolism. Previous studies revealed that a common mutation in MTHFR gene C677T is related to hyperhomocysteinemia and occlusive vascular pathology. In the current study, we determined the prevalence of a newly described mutation in the human MTHFR gene A1298C, and the already known C677T mutation, and related them to plasma total homocysteine and folate concentrations. We studied 377 Jewish subjects, including 190 men and 186 women aged 56.8 +/- 13 y (range 32-95 y). The frequency of the homozygotes for the A1298C and the C677T MTHFR mutations was common in the Jewish Israeli population (0.34 and 0.37, respectively). Subjects homozygous (TT) for the C677T mutation had significantly greater plasma total homocysteine concentrations (P < 0.01) than subjects without the mutation (CC). Homozygotes (CC) for the A1298C mutation did not have elevated plasma total homocysteine concentrations. Our study indicated that subjects with the 677CC/1298CC genotype had significantly lower concentrations (P < 0. 05) than those with a 677CC/1298AA genotype. Neither mutation (the A1298C and the C677T) was associated with established cardiovascular risk factors such as hypertension, elevated total cholesterol or body mass index. PMID:10460200

Friedman, G; Goldschmidt, N; Friedlander, Y; Ben-Yehuda, A; Selhub, J; Babaey, S; Mendel, M; Kidron, M; Bar-On, H

1999-09-01

49

Maternal MTHFR C677T polymorphism and congenital heart defect risk in the Chinese Han population: a meta-analysis.  

PubMed

Numerous studies have evaluated the association between the maternal C677T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene and congenital heart defect (CHD) risk in the Chinese Han population. However, the specific association is still controversial. Six separate studies with 1089 subjects in the Chinese Han population on the relationship between the C677T polymorphism and CHDs were analyzed by meta-analysis, upon database search. The fixed-effect model or random-effect model was selected to calculate the pooled odds ratio (ORs) and its corresponding 95% confidence interval (95%CI) when appropriate. The Begg test was used to measure publication bias. Sensitivity analyses were performed to insure authenticity of the outcome. Meta-analysis of the results showed significant associations between the maternal C677T polymorphism and CHD risk (CC vs TT: OR = 0.65, 95%CI = 0.44-0.96). Limiting the analysis to the studies with controls in the Hardy-Weinberg equilibrium and the results indicate that the meta-analysis was statistically significant. Results of Begg's funnel plot showed that there was no publication bias (all P > 0.05). The present meta-analysis suggested that the maternal C677T polymorphism is a risk factor for CHDs in the Chinese Han population. PMID:24338416

Chen, K H; Chen, L L; Li, W G; Fang, Y; Huang, G Y

2013-01-01

50

The methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and tumor risk: evidence from 134 case-control studies.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism, which is essential for DNA synthesis and methylation. Genetic variations in the MTHFR gene seem to contribute to a decreased activity of MTHFR, ultimately confer increased susceptibility to cancer. As the most extensively studied polymorphism, MTHFR C677T polymorphism was shown to contribute to cancer susceptibility but the results were inconsistent. The authors performed a meta-analysis including 134 studies (46,207 cases and 69,160 controls) to address the issue. Odds ratios (ORs) with corresponding 95% confidence intervals (CIs) were used to assess the association. Overall, a significant elevated risk of cancer was associated with the MTHFR C677T polymorphism in T-allele versus C-allele comparison (OR = 1.06, 95% CI 1.02-1.11, P(heterogeneity) < 0.001), homozygote model (OR = 1.08, 95% CI 1.01-1.17, P(heterogeneity) < 0.001) and dominant model (OR = 1.05, 95% CI 1.00-1.10, P(heterogeneity) < 0.001). In the stratified analyses, significantly increased cancer risks were indicated among Asians in all genetic models except for heterozygote model. Further analysis revealed that C677T was significantly associated with an increased risk of esophageal and stomach cancer. This meta-analysis supports an association between the MTHFR C677T polymorphism and increased risk of esophageal and stomach cancer, especially among Asians. Additionally, more high-quality studies and that the covariates responsible for heterogeneity should be controlled to obtain a more conclusive response about the function of MTHFR C677T in cancer. PMID:24744129

Tang, Min; Wang, Shang-Qian; Liu, Bian-Jiang; Cao, Qiang; Li, Bing-Jie; Li, Peng-Chao; Li, Yong-Fei; Qin, Chao; Zhang, Wei

2014-07-01

51

Risk association of meningiomas with MTHFR C677T and GSTs polymorphisms: a meta-analysis  

PubMed Central

Previous studies have shown that the single nucleotide polymorphisms (SNPs) in Methylenetetrahydrofolate reductase (MTHFR) and Glutathione S-transferases (GSTs, including GSTM1, GSTT1) genes play an important role in determining the response of an individual to environmental pathogenesis and significantly relate to incidences of various human tumors, including brain tumors. However, these genes’ polymorphisms on meningioma risk remains poorly understood. The relevant inferences from previous studies are hindered by their limited statistical power and conflicting results. The aim of this meta-analysis is to provide a relatively comprehensive account of the association between these polymorphisms and human meningioma risk. A literature search for eligible studies published before January 1, 2014 was conducted in PubMed, Embase, Web of Science, Cochrane Library, and CNKI databases. Pooled odds ratios (OR) with their corresponding 95% confidence intervals (95% CI) were used to evaluate the strength of the association under a fixed or random effect model according to heterogeneity test results. Heterogeneity and publication bias were evaluated. All statistical analyses were conducted by using the software of STATA 12.0 (STATA Corporation, College Station, TX, USA). For MTHFR C677T (dbSNP: rs1801133) (C T) polymorphism, 9 individual case-control studies from six publications with 1,615 cases and 1,909 controls were obtained. For GSTM1 null polymorphism, there were 4 studies with 417 cases and 1,735 controls. For GSTT1 null polymorphism, there were 4 studies with 405 cases and 1,622 controls. The combined results for the MTHFR C677T show that carriers of the CT genotype may be associated with a higher meningioma risk (OR = 1.20, 95% CI 1.05-1.38, P = 0.009). Stratified analyses show that Caucasians have significantly higher risk if they carry the CT genotype of MTHFR (OR = 1.31, 95% CI 1.05-1.63, P = 0.02). Risk of Caucasians carrying TT + CT genotype is also significantly higher (OR = 1.27, 95% CI 1.02-1.58, P = 0.03). Risk of Caucasians carrying TT genotype is not significantly different compared to control population (OR = 0.96, 95% CI 0.69-1.34, P = 0.82). All of the enrolled studies about GSTM1/GSTT1 are on Caucasians. The pooled ORGSTM1 and ORGSTT1 were not significant in Caucasian population. These results indicate SNPs of MTHFR C677T are related to meningioma risk with ethnic differences. Caucasians carrying CT genotype of MTHFR C677T have significantly higher meningioma susceptibility. SNPs of GSTM1/GSTT1 are not related to meningioma risk.

Ding, Hao; Liu, Wei; Yu, Xinyuan; Wang, Lei; Shao, Lingmin; Yi, Wei

2014-01-01

52

MTHFR polymorphisms C677T and A1298C and associations with IVF outcomes in Brazilian women.  

PubMed

The aim of this study was to investigate the association between MTHFR gene polymorphisms and IVF outcomes in Brazilian women undergoing assisted reproduction treatment. A prospective study was conducted in the Human Reproduction Department at the ABC University School of Medicine and the Ideia Fertility Institute between December 2010 and April 2012. The patient population was 82 women undergoing assisted reproduction cycles. The MTHFR polymorphisms C677T and A1298C were evaluated and compared with laboratory results and pregnancy rates. The C677T variant was associated with proportions of mature (P=0.006) and immature (P=0.003) oocytes whereas the A1298C variant was associated with number of oocytes retrieved (P=0.044). The polymorphisms, whether alone or in combination, were not associated with normal fertilization, good-quality embryo or clinical pregnancy rates. This study suggests that the number and maturity of oocytes retrieved may be related to the MTHFR polymorphisms C677T and A1298C. It is believed that folate has a crucial function in human reproduction and that folate deficiency can compromise the function of the metabolic pathways it is involved in, leading to an accumulation of homocysteine. The gene MTHFR encodes the 5-MTHFR enzyme, which is involved in folate metabolism, and C677T/A1298C polymorphisms of this gene are related to decreased enzyme activity and consequent changes in homocysteine concentration. Folate deficiency and hyperhomocysteinaemia can also compromise fertility and lead to pregnancy complications by affecting the development of oocytes, preparation of endometrial receptivity, implantation of the embryo and pregnancy. In folliculogenesis, hyperhomocysteinaemia can activate apoptosis, leading to follicular atresia and affecting the maturity of oocytes and the quality of embryos cultured in vitro. This study was performed to investigate the association between MTHFR polymorphisms and IVF outcomes in women undergoing assisted reproduction treatment. PMID:24746944

D'Elia, Priscila Queiroz; dos Santos, Aline Amaro; Bianco, Bianca; Barbosa, Caio Parente; Christofolini, Denise Maria; Aoki, Tsutomu

2014-06-01

53

MTHFR polymorphic variant C677T is associated to vascular complications in sickle-cell disease.  

PubMed

Vaso-occlusion is a determinant for most signs and symptoms of sickle-cell anemia (SCA). The mechanisms involved in the pathogenesis of vascular complications in SCA remain unclear. It is known that genetic polymorphisms associated with thrombophilia may be potential modifiers of clinical features of SCA. The genetic polymorphisms C677T and A1298C relating to the enzyme methylenetetrahydrofolate reductase (MTHFR), a clotting Factor V Leiden mutation (1691G?A substitution of Factor V Leiden), and the mutant prothrombin 20210A allele were analyzed in this study. The aim was to find possible correlations with vascular complications and thrombophilia markers in a group of SCA patients in Pernambuco, Brazil. The study included 277 SCA patients, divided into two groups: one consisting of 177 nonconsanguineous SCA patients who presented vascular manifestations of stroke, avascular necrosis, leg ulcers, priapism, and acute chest syndrome (group 1); and the other consisting of 100 SCA patients without any reported vascular complication (group 2). Molecular tests were done using either polymerase chain reaction (PCR) restriction fragment length polymorphism or allele-specific PCR techniques. Comparisons between the groups were made using the ?(2) test. The 677 CT and TT genotypes showed a significant risk of vascular complications (p=0.015). No significant associations between the groups were found when samples were analyzed for the MTHFR A1298C allele (p=0.913), Factor V G1691 (p=0.555), or prothrombin G20210A mutation (p=1.000). The polymorphism MTHFR C677T seemed to be possibly predictive for the development of some vascular complications in SCA patients among this population. PMID:22924497

Hatzlhofer, Betânia L D; Bezerra, Marcos André C; Santos, Magnun N N; Albuquerque, Dulcinéia M; Freitas, Elizabete M; Costa, Fernando F; Araújo, Aderson S; Muniz, Maria Tereza C

2012-09-01

54

Synergistic effects of the MTHFR C677T polymorphism and hypertension on spatial navigation.  

PubMed

Navigation skills deteriorate with age, but the mechanisms of the decline are poorly understood. Part of the decrement may be due to age-related vascular risk factors. The T allele in a C677T variant in methylenetetrahydrofolate reductase (MTHFR) gene is associated with elevated plasma homocysteine, which is detrimental to vascular integrity and has been linked to cognitive decline. We inquired if a combination of physiological (hypertension) and genetic (MTHFR 677T) vascular risks has a synergistic negative impact on cognitive performance in otherwise healthy adults. We tested 160 participants (18-80 years old) on a virtual water maze. Advanced age, female sex, and hypertension were associated with poorer performance. However, hypertensive carriers of the T allele performed significantly worse than the rest of the participants at all ages. These findings indicate that hypertension combined with a genetic vascular risk factor may significantly increase risk for cognitive impairment. PMID:19013496

Deshmukh, Awantika; Rodrigue, Karen M; Kennedy, Kristen M; Land, Susan; Jacobs, Bradley S; Raz, Naftali

2009-02-01

55

Association between methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and age of onset in schizophrenia.  

PubMed

Different lines of evidence indicate that methylenetetrahydrofolate reductase (MTHFR) functional gene polymorphisms, causative in aberrant folate-homocysteine metabolism, are associated with increased vulnerability to several heritable developmental disorders. Opposing views are expressed considering the possible association between MTHFR and susceptibility for schizophrenia. In order to evaluate if age of onset could explain some of this discrepancy we investigated the relationship between two functional MTHFR gene polymorphisms and age at onset in this disorder. Scandinavian patients (n = 820) diagnosed with schizophrenia, schizoaffective disorder, and schizophreniform disorder were investigated. Two functional MTHFR single nucleotide polymorphisms (SNPs; rs1801131 and rs1801133) were genotyped and the effect of MTHFR polymorphisms on the age of onset was examined with survival analysis. In an attempt to replicate the findings from the Scandinavian sample, the association between rs1801133 and age at onset was also analyzed in Chinese high-risk families, with two or more affected siblings (n = 243). Among the Scandinavian patients the functional MTHFR SNP rs1801133 (C677T) significantly affected age at onset of schizophrenia in a dose-dependent manner (P = 0.0015), with lower age of onset with increasing numbers of the mutant T-allele. There was no evidence of rs1801131 (A1298C) affecting age of onset in schizophrenia. Within the Chinese high-risk families carriers of the MTHFR 677T allele showed earlier age at onset than siblings being homozygous for the wild-type allele (P = 0.008). The MTHFR C677T polymorphism may play a role as a modifying factor for age of onset in schizophrenia. PMID:19746410

Vares, Maria; Saetre, Peter; Deng, Hong; Cai, Guiqing; Liu, Xiehe; Hansen, Thomas; Rasmussen, Henrik B; Werge, Thomas; Melle, Ingrid; Djurovic, Srdjan; Andreassen, Ole A; Agartz, Ingrid; Hall, Håkan; Terenius, Lars; Jönsson, Erik G

2010-03-01

56

Homocysteine and methylenetetrahydrofolate reductase C677T and A1298C polymorphisms in Tunisian patients with severe coronary artery disease.  

PubMed

Elevation in homocysteine and methylenetetrahydrofolate reductase (MTHFR) gene variants, C677T and A1298C, have been linked with atherothrombosis. However their exact contribution to coronary artery disease (CAD) remains controversial. Moreover, data from Tunisian patients are scarse. We examined the association of MTHFR C677T and A1298C, and changes in plasma homocysteine in 352 Tunisian patients with angiographically-demonstrated CAD, and 390 age and gender-matched healthy subjects. Significantly higher frequency of 677T allele and homozygous 677T/T genotype were seen in patients vs. control subjects; the distribution of A1298C alleles and genotypes being comparable in the two groups. Specific MTHFR haplotypes comprising 677C/1298A (P < 0.001) and 677T/1298A (P < 0.001) were negatively and positively associated with CAD, respectively. Plasma homocysteine concentration was significantly higher in 677T/T genotype with respect to 677C/C and 677C/T genotypes in patients and controls, but homocysteine levels were generally comparable between both groups. Univariate analysis identified 677T/1298A (P = 0.033) haplotype to be positively associated with CAD, which remained significant by multivariate analysis after adjusting for a number of covariates (P = 0.038). MTHFR C677T, but not A1298C SNPs, is associated with CAD and with elevated homocysteine levels in a Tunisian population. The negative and positive association of the 1298A allele with CAD being indicative of a neutral (absent) effect of the A1298C SNP on disease pathogenesis. PMID:18204887

Ghazouani, Lakhdar; Abboud, Nesrine; Mtiraoui, Nabil; Zammiti, Walid; Addad, Faouzi; Amin, Haitham; Almawi, Wassim Y; Mahjoub, Touhami

2009-02-01

57

MTHFR C677T and A1298C polymorphisms are risk factors for Down's syndrome in Indian mothers.  

PubMed

Down's syndrome (DS), a chromosomal disorder due to trisomy 21, results mostly from nondisjunction in maternal meiosis. The present case-control study examined the association of genetic polymorphisms with predisposition to nondisjunction. Two common polymorphisms (SNPs), C677T and A1298C, in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene involved in folate metabolism, are known to lower the activity of this enzyme. Three hundred and fourteen mothers (with DS children and controls), mostly from the eastern states of India, were genotyped for the two above-mentioned SNPs. Significant association with both of these SNPs were detected, more specifically, in the mothers of DS children homozygous for the polymorphic alleles 677 T and 1298 C. The relative risk of T (C677T) and C (A1298C) homozygosity in mothers for DS-affected pregnancy was 7 (OR 7.67, 95% CI 1.67-35.08, P=0.003) and 4 (OR 4.40, 95% CI 1.45-13.26, P=0.008), respectively. Moreover, all 677TT mothers studied were less than 31 years of age, whereas no correlation with maternal age was observed for A1298C genotypes. Interestingly, all of the young 677TT mothers had either a first- or secondborn child with DS. Thus, this study reports that young Indian mothers with TT genotypes are genetically predisposed to nondisjunction due to abnormal folate metabolism. PMID:16489479

Rai, Amit Kumar; Singh, Satya; Mehta, Stuti; Kumar, Ashok; Pandey, L K; Raman, Rajiva

2006-01-01

58

Effect of multivitamins on plasma homocysteine in patients with the 5,10 methylenetetrahydrofolate reductase C677T homozygous state.  

PubMed

The role of hyperhomocysteinemia (HHcy) as a cardiovascular risk factor remains a matter of debate, while it correlates with folates, it demonstrates inverse correlation with plasma homocysteine (Hcy) levels and vitamin B12 levels and reduces plasma Hcy levels following supplementation with multivitamins. The purpose of this study was to demonstrate that administering multivitamins at specific doses for 90 days restores normal plasma Hcy levels in women who are homozygous for the thermolabile variant of 5,10 methylenetetrahydrofolate reductase (MTHFR C677T). We enrolled 106 healthy females aged between 30 and 42 years, who were non-smokers, non-vegetarian, normotensive and who had no history of food abuse in the previous months. Only females were enrolled in order to rule out any bias due to the variation in Hcy plasma concentrations between males and females. Patient blood sampling was performed in order to determine plasma Hcy, serum folic acid and vitamin B12 levels. Furthermore, molecular characterization of the C677T polymorphism present in the MTHFR gene, was also performed. The results of this study demonstrated that supplementation with specific multivitamins restores normal plasma Hcy levels, regardless of the MTHFR genotype. Furthermore, it is unnecessary to adminster high doses of folate to reduce plasma Hcy levels, and administering high doses of folate may cause pro-inflammatory and pro-proliferative effects. PMID:23818036

Dell'edera, Domenico; Tinelli, Andrea; Milazzo, Giusi Natalia; Malvasi, Antonio; Domenico, Carone; Pacella, Elena; Pierluigi, Compagnoni; Giuseppe, Tarantino; Marcello, Guido; Francesco, Lomurno; Epifania, Annunziata Anna

2013-08-01

59

The MTHFR C677T polymorphism contributes to increased risk of Alzheimer's Disease: Evidence based on 40 case-control studies.  

PubMed

The association between methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism and Alzheimer's Disease (AD) risk has been widely reported with inconsistent results. We performed an updated meta-analysis of all available studies to clarify this situation. We conducted a comprehensive literature search in PubMed Alzgene, Embase, and Chinese Biomedical Literature database (CBM) for the period up to June 2014. Finally, a total of 40 case-control studies with 4503 AD cases and 5767 controls were included. Overall, significant increased AD risk was found, when all studies were pooled into the meta-analysis. In subgroup analyses stratified by ethnicity, age of onset, and APOE ?4 status, significant increased AD risk was found in Asians, late-onset AD, and APOE ?4 carriers, but not in Caucasians, early-onset AD, and non-APOE ?4 carriers. The present meta-analysis suggested that the MTHFR is a candidate gene for AD susceptibility. The MTHFR C677T polymorphism may be a risk factor for AD in Asians, APOE ?4 carriers, and late-onset AD. Further, investigations taking the potential gene-gene and gene-environmental interactions into consideration for the MTHFR C677T polymorphism should be conducted. PMID:25486592

Peng, Qiliu; Lao, Xianjun; Huang, Xiuli; Qin, Xue; Li, Shan; Zeng, Zhiyu

2015-01-23

60

High prevalence of three prothrombotic polymorphisms among Palestinians: factor V G1691A, factor II G20210A and methylenetetrahydrofolate reductase C677T.  

PubMed

Factor V leiden G1691A/R506Q (FVL), prothrombin G20210A (FII) and methylenetetrahydrofolate reductase (MTHFR) C677T are related genetic risk factors for venous thromboembolism. Analysis for those mutations is increasingly being performed on patients exhibiting hypercoagulability. The objective of this study was to determine the prevalence of FVL, FII-G20210A and MTHFR-C677T polymorphisms and their coexistence among apparently healthy Palestinians. After institutional approval, 303 apparently healthy students from An-Najah University representative to North and South regions of West Bank with no previous history of cardiovascular diseases participated in this study. A uniform questionnaire was used to collect relevant information through personal interview with the subjects. The collected information included gender, age, smoking habits, weight and height, diseases such as diabetes, cardiovascular and family history of CVD. The frequencies of allelic distribution of the three prothrombotic polymorphisms factor V G1691A/R506Q), prothrombin G2010A, and MTHFR-C677T were 0.114, 0.050 and 0.071, respectively. The prevalence of the three thrombotic polymorphisms (FVL, FII G20210A and MTHFR-C677T) were 20.1, 9.1 and 13.8 %, respectively. Statistical analysis for factor V leiden showed no significant association between place of residence (P value = 0.953) and gender (P value >0.082). The data presented in this study showed the highest prevalence of FVL among healthy Palestinians compared to other populations and this important finding should be followed in terms of clinical significance. PMID:22528331

Hussein, Ayman S

2012-10-01

61

Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility  

PubMed Central

AIM: To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility. METHODS: Systematic searches were performed on the electronic databases PubMed, ISI, Web of knowledge, CNKI and Wanfang, as well as manual searching of the references of the identified articles. A total of 26 papers were included in this meta-analysis. Overall and subgroup analyses were performed. Odds ratio (OR) and 95%CI were used to evaluate the associations between MTHFR polymorphisms and GC risk. The I2 statistics were used to evaluate between-study heterogeneity. Sensitivity analysis was also performed. RESULTS: Increased risk was found for the MTHFR C677T polymorphism under four genetic models (TT + CT vs CC: OR = 1.23, P = 0.002; T vs C: OR = 1.15, P = 0.001; TT vs CC: OR = 1.37, P = 0.0005; TT vs CT + CC: OR = 1.17, P = 0.0008). Subgroup analysis by ethnicity suggested that C677T polymorphism conferred a risk of GC in eastern but not in western populations. Stratification by tumor site showed an association between the C677T polymorphism and gastric cardia cancer and non-cardia GC in the worldwide population and in eastern populations. Regardless of comparisons with controls or diffuse-type GC, a positive association was found for the C677T polymorphism and an increased risk of intestinal-type GC in the whole population and in western populations. With regard to the A1298C polymorphism, we found that genotype CC was significantly decreased and conferred protection against GC in eastern populations (CC vs AA: OR = 0.44, P = 0.03; CC vs AC + AA: OR = 0.46, P = 0.04). CONCLUSION: MTHFR C677T polymorphism is a risk factor for GC, and the A1298C polymorphism may be a protective factor against GC in eastern populations. PMID:25170232

Xia, Lei-Zhou; Liu, Yi; Xu, Xiao-Zhou; Jiang, Peng-Cheng; Ma, Gui; Bu, Xue-Feng; Zhang, Yong-Jun; Yu, Feng; Xu, Ke-Sen; Li, Hua

2014-01-01

62

MTHFR C677T polymorphism contributes to prostate cancer risk among Caucasians: A meta-analysis of 3511 cases and 2762 controls.  

PubMed

Published data regarding the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and prostate cancer risk have been conflicting. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR C677T and A1298C polymorphisms and prostate cancer risk. Six studies including 3511 cases and 2762 controls described C677T genotypes, among which four articles totalling 838 cases and 1121 controls described A1298C genotypes, were involved in this meta-analysis. Overall meta-analysis indicated that the 677T allele was more likely to exert a protective effect on prostate cancer risk (OR=0.81, 95% CI: 0.68-0.98) with a recessive genetic model. No association was found for the 677CT genotype and the 677TT mutant homozygote with prostate cancer risk compared with 677CC, with OR=1.13 (95% CI: 0.88-1.45) and OR=0.85 (95% CI: 0.71-1.03), respectively. No evidence of an association of MTHFR A1298C polymorphism with prostate cancer was found. This meta-analysis supports that the C677T of the MTHFR gene is a low-penetrance susceptibility gene for prostate cancer, and might provide protective effects against prostate cancer risk. PMID:19223177

Bai, Jian-Ling; Zheng, Ming-Hua; Xia, Xian; Ter-Minassian, Monica; Chen, Yong-Ping; Chen, Feng

2009-05-01

63

Prevalence of MTHFR C677T and MS A2756G polymorphisms in major depressive disorder, and their impact on response to fluoxetine treatment  

PubMed Central

Objective To examine the prevalence of the C677T polymorphism of the methylene tetrahydrofolate reductase (MTHFR) gene and the A2756G polymorphism of methionine synthase (MS), and their impact on antidepressant response. Methods We screened 224 subjects (52% female, mean age 39 ± 11 years) with SCID-diagnosed major depressive disorder (MDD), and obtained 194 genetic samples. 49 subjects (49% female, mean age 36 ± 11 years) participated in a 12-week open clinical trial of fluoxetine 20–60 mg/day. Association between clinical response and C677T and A2756G polymorphisms, folate, B12, and homocysteine was examined. Results Prevalence of the C677T and A2756G polymorphisms was consistent with previous reports (C/C=41%, C/T=47%, T/T=11%, A/A=66%, A/G=29%, G/G=4%). In the fluoxetine-treated subsample (n=49), intent-to-treat (ITT) response rates were 47% for C/C subjects and 46% for pooled C/T and T/T subjects (nonsignificant). ITT response rates were 38% for A/A subjects and 60% for A/G subjects (nonsignificant), with no subjects exhibiting the G/G homozygote. Mean baseline plasma B12 was significantly lower in A/G subjects compared to A/A, but folate and homocysteine levels were not affected by genetic status. Plasma folate was negatively associated with treatment response. Conclusion The C677T and A2756G polymorphisms did not significantly affect antidepressant response. These preliminary findings require replication in larger samples. PMID:22789065

Mischoulon, David; Lamon-Fava, Stefania; Selhub, Jacob; Katz, Judith; Papakostas, George I.; Iosifescu, Dan V.; Yeung, Albert S.; Dording, Christina M.; Farabaugh, Amy H.; Clain, Alisabet J.; Baer, Lee; Alpert, Jonathan E.; Nierenberg, Andrew A.; Fava, Maurizio

2014-01-01

64

Methylenetetrahydrofolate reductase polymorphism C677T is a protective factor for pediatric acute lymphoblastic leukemia in the Chinese population: a meta-analysis.  

PubMed

Two polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, C677T and A1298C, were hypothesized to decrease the risk of acute lymphoblastic leukemia (ALL). Studies examining the associations between these two polymorphisms and ALL susceptibility drew inconsistent results. To obtain a reliable conclusion in a Chinese population, we carried out a meta-analysis. In total, 11 studies on C677T polymorphism (1597 cases and 2295 controls) and 10 studies on A1298C polymorphism (1553 cases and 2224 controls) were included in the meta-analysis. We found a significant association between the 677T variant and reduced ALL risk in Chinese children (Dominant model: odds ratio [OR(FE)]=0.73, 95% confidence interval [CI]: 0.63-0.86, p<0.01). Heterogeneity between the studies in the children subgroup was weak and vanished after excluding one study deviating from HWE in the control group (p>0.1). In the adult subgroup, there was no significant association between the C677T variant and ALL risk (Dominant model: OR(RE)=0.88, 95% CI: 0.45-1.72, p=0.72). Significant heterogeneity was found in the adult subgroup in all the genetic model tests (p<0.1). The A1298C polymorphism had an effect on ALL risk neither in adults (Dominant model: OR(FE)=0.95, 95% CI: 0.71-1.27, p=0.72) nor in children (Dominant model: OR(FE)=1.02, 95% CI: 0.87-1.21, p=0.77). No significant heterogeneity between studies on A1298C polymorphism was found in the meta-analysis (p>0.1). The results showed that there was a protective effect of the MTHFR C677T variant on ALL risk in Chinese children. PMID:23061880

Wang, Haigang; Meng, Lujing; Zhao, Lixia; Wang, Jiali; Liu, Xinchun; Mi, Wenjie

2012-12-01

65

Primary thrombophilia in Mexico. II. Factor V G1691A (Leiden), prothrombin G20210A, and methylenetetrahydrofolate reductase C677T polymorphism in thrombophilic Mexican mestizos.  

PubMed

We have shown that in Mexican mestizo patients with clinical features of primary thrombophilia, 39% have activated protein C resistance phenotype, 5% protein C deficiency, and 2% protein S deficiency. In the present study, in a group of 37 thrombophilic Mexicans and 50 normal controls, we assessed the factor V G1691A (Leiden), the prothrombin G20210A, and the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphisms. Four patients were found to be heterozygous for factor V Leiden, 5 heterozygous for the prothrombin 20210, 16 heterozygous, and 6 homozygous for the MTHFR 677. There were four individuals with co-segregation of alleles: two heterozygotes for the factor V Leiden/prothrombin 20210, one heterozygote for prothrombin 20210/MTHFR 677, and one heterozygote for prothrombin 20210/homozygote for MTHFR 677. For factor V Leiden, prothrombin 20210, and MTHFR 677 mutations, the allele frequencies were respectively 1% (+/-0.2%, alpha = 0.05), <1% and 51% (+/-5%, alpha = 0.05), with calculated relative risks for thrombosis of 5.94 (P = 0.08), >7.66 (P < 0.05), and 0.44 (P NS), respectively. In Mexican mestizo thrombophilic patients, the low prevalence of the factor V Leiden mutation (10.8%) and the high prevalence of the prothrombin 20210 mutation (13.5%) contrast with those identified in Caucasian thrombophilic patients (21% and 6%, respectively; P < 0.01). On the other hand, the high prevalence of the MTHFR 677 mutation gene both in normal controls (78%) and thrombophilic patients (61%) does not support a role of this mutation in the thrombogenesis of Mexican mestizo patients. PMID:11426488

Ruiz-Argüelles, G J; Garcés-Eisele, J; Reyes-Núñez, V; Ramírez-Cisneros, F J

2001-01-01

66

MTHFR C677T and A1298C polymorphisms: diet, estrogen, and risk of colon cancer.  

PubMed

5,10-methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism, diverting metabolites toward methylation reactions or nucleotide synthesis. Using data from an incident case-control study (1608 cases and 1972 controls) we investigated two polymorphisms in the MTHFR gene, C677T and A1298C, and their associations with risk of colon cancer. All of the combined genotypes were evaluated separately, and the 1298AA/677CC (wild-type/wild-type) group was considered the reference group. Among both men and women, the 677TT/1298AA (variant/wild-type) genotype was associated with a small reduction in risk [men: odds ratio (OR), 0.7, 95% confidence interval (CI), 0.5-1.0; women: OR, 0.8, 95% CI, 0.5-1.2]. However, the 677CC/1298CC (wild-type/variant) genotype was associated with a statistically significant lower risk among women (OR, 0.6; 95% CI, 0.4-0.9) but not men. When the polymorphisms were considered individually, for A1298C a significant risk reduction associated with the homozygous variant CC genotype was seen among women only (OR, 0.6; 95% CI, 0.5-0.9), and nonstatistically significant reduced risks were observed for the variant 677 TT genotypes among both men and women. Stratification by nutrient intakes showed inverse associations with higher intakes of folate, vitamin B(2), B(6), B(12), and methionine among women with the MTHFR 677CC/1298AA genotypes, but not those with 677TT/1298AA. We observed opposite risk trends for both MTHFR variants, depending on whether women used hormone-replacement therapy or not (P for interaction = <.01). In summary, this study supports recent findings that the MTHFR A1298C polymorphism may be a predictor of colon cancer risk and have functional relevance. The possible interaction with hormone-replacement therapy warrants additional investigation. PMID:14973104

Curtin, Karen; Bigler, Jeannette; Slattery, Martha L; Caan, Bette; Potter, John D; Ulrich, Cornelia M

2004-02-01

67

The MTHFR C677T polymorphism and global DNA methylation in oral epithelial cells  

PubMed Central

DNA methylation is mediated by DNA methyltransferases (DNMTs) that add a methyl group to the 5?-carbon of cytosine. The enzyme methylenetetrahydrofolate reductase (MTHFR) catalyzes the reduction of 5,10-methylenetetrahydrofolate to 5-methyltetrahydrofolate in the rate-limiting step of the cycle involving the methyl donor S-adenosyl-L-methionine (SAM). The MTHFR C677T polymorphism results in a thermolabile enzyme with reduced activity that is predicted to influence the DNA methylation status. In this study, we investigated the impact of the MTHFR C677T polymorphism on the global DNA methylation of oral epithelial cells obtained from 54 healthy subjects. There were no significant differences in global DNA methylation among the MTHFR CC, CT and TT genotypes (p = 0.75; Kruskal-Wallis test). PMID:24385849

de Arruda, Isabela Tatiana Sales; Persuhn, Darlene Camati; de Oliveira, Naila Francis Paulo

2013-01-01

68

The methylenetetrahydrofolate reductase C677T polymorphism influences risk of esophageal cancer in Chinese.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) plays a central role in folate metabolism. This study with 381 esophageal cancer patients and 432 healthy controls was conducted to examine the association of MTHFR C677T and A1298C polymorphisms with susceptibility to esophageal cancer (EC) in a Chinese population. Compared with the CC genotype of MTHFR C677T, subjects carrying homozygote TT and variant genotypes (CT+TT) demonstrated reduced risk of EC with adjusted ORs (95% CI) of 0.44 (0.28-0.71) and 0.57 (0.37-0.88), respectively. However, no association was found between the MTHFR A1298C polymorphism and the risk of EC. Comparing to haplotype CA, haplotypes TA and TC could reduce the susceptibility to EC with adjusted ORs (95% CI) of 0.61(0.47-0.79) and 0.06 (0.01-0.43), respectively. In conclusion, the present study suggested that the MTHFR C677T polymorphism can markedly influence the risk of EC in Chinese. PMID:23803097

Qu, Hong-Hong; Cui, Li-Hong; Wang, Ke; Wang, Peng; Song, Chun-Hua; Wang, Kai-Juan; Zhang, Jian-Ying; Dai, Li-Ping

2013-01-01

69

MTHFR C677T Predisposes to POAG but Not to PACG in a North Indian Population: A Case Control Study  

PubMed Central

Hyperhomocysteinemia induced by the C677T genetic variant in MTHFR (methylenetetrahydrofolate reductase) has been implicated in neuronal cell death of retinal ganglion cells (RGC), which is a characteristic feature of glaucoma. However, association of MTHFR C677T with glaucoma has been controversial because of inconsistent results across association studies. Association between MTHFR C677T and glaucoma has not been reported in Indian population. Therefore, with a focus on neurodegenerative death of RGC in glaucoma, the current study aimed to investigate association of MTHFR C677T with Primary Open Angle Glaucoma (POAG) and Primary Angle Closure Glaucoma (PACG) in a North Indian population. A total of 404 participants (231 patients and 173 controls) were included in this study. Genotyping was performed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism. A few random samples were also tested by direct sequencing. Genotypic and allelic distributions of the POAG and PACG cohorts were compared to that of controls by chi-square test and odds ratios were reported with 95% confidence intervals. Genotypic and allelic distributions between POAG cases and controls were significantly different (p?=?0.03 and p?=?0.01 respectively). Unlike POAG, we did not find significant difference in the genotypic and allelic distributions of C677T between PACG cases and controls (p>0.05). We also observed a higher proportion of TT associated POAG in females than that in males. However, this is a preliminary indication of gender specific risk of C677T that needs to be replicated in a larger cohort of males and females. The present investigation on MTHFR C677T and glaucoma reveals that the TT genotype and T allele of this polymorphism are significant risk factors for POAG but not for PACG in North Indian population. Ours is the first report demonstrating association of MTHFR C677T with POAG but not PACG in individuals from North India. PMID:25054348

Gupta, Shashank; Bhaskar, Pradeep Kumar; Bhardwaj, Ritu; Chandra, Abhishek; Chaudhry, Vidya Nair; Chaudhry, Prashaant; Ali, Akhtar; Mukherjee, Ashim; Mutsuddi, Mousumi

2014-01-01

70

Interaction between the MTHFR C677T polymorphism and traumatic childhood events predicts depression.  

PubMed

Childhood trauma is associated with the onset and recurrence of major depressive disorder (MDD). The thermolabile T variant of the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism (rs1801133) is associated with a limited (oxidative) stress defense. Therefore, C677T MTHFR could be a potential predictor for depressive symptomatology and MDD recurrence in the context of traumatic stress during early life. We investigated the interaction between the C677T MTHFR variant and exposure to traumatic childhood events (TCEs) on MDD recurrence during a 5.5-year follow-up in a discovery sample of 124 patients with recurrent MDD and, in an independent replication sample, on depressive symptomatology in 665 healthy individuals from the general population. In the discovery sample, Cox regression analysis revealed a significant interaction between MTHFR genotype and TCEs on MDD recurrence (P=0.017). Over the 5.5-year follow-up period, median time to recurrence was 191 days for T-allele carrying patients who experienced TCEs (T+ and TCE+); 461 days for T- and TCE+ patients; 773 days for T+ and TCE- patients and 866 days for T- and TCE- patients. In the replication sample, a significant interaction was present between the MTHFR genotype and TCEs on depressive symptomatology (P=0.002). Our results show that the effects of TCEs on the prospectively assessed recurrence of MDD and self-reported depressive symptoms in the general population depend on the MTHFR genotype. In conclusion, T-allele carriers may be at an increased risk for depressive symptoms or MDD recurrence after exposure to childhood trauma. PMID:23900311

Lok, A; Bockting, C L H; Koeter, M W J; Snieder, H; Assies, J; Mocking, R J T; Vinkers, C H; Kahn, R S; Boks, M P; Schene, A H

2013-01-01

71

Laboratory informatics based evaluation of methylene tetrahydrofolate reductase C677T genetic test overutilization  

PubMed Central

Background: Laboratory data can provide a wide range of information to estimate adherence to guidelines and proper utilization of genetic testing. The methylene tetrahydrofolate reductase (MTHFR) C677T variant has been demonstrated to have negligible utility in patient management. However, the testing of this variant remains pervasive. The purpose of this study was to develop methods to analyze concordance of clinician ordering practices with national guidelines. Methods: We used laboratory data to extract specific data elements including patient demographics, timestamps, physician ordering logs and temporal relationship to chemistry requests to examine 245 consecutive MTHFR tests ordered in 2011 at an academic tertiary center. A comprehensive chart review was used to identify indications for testing. These results were correlated with a retrospective analysis of 4,226 tests drawn at a range of hospitals requesting testing from a national reference laboratory over a 2-year period. MTHFR ordering practices drawn from 17 institutions were examined longitudinally from 2002 to 2011. Results: Indications for testing included cerebrovascular events (40.0%) and venous thrombosis (39.1%). Family history prompted testing in eight cases. Based on acceptable hypercoagulability guidelines recommending MTHFR C677T testing only in the presence of elevated serum homocysteine, 10.6% (22/207) of adult patients met an indicated threshold at an academic tertiary center. Among 77 institutions, 14.5% (613/4226) of MTHFR testing met recommendations. Conclusion: We demonstrate an effective method to examine discreet elements of a molecular diagnostics laboratory information system at a tertiary care institution and to correlate these findings at a national level. Retrospective examination of clinicians’ request of MTHFR C677T genetic testing strongly suggests that clinicians have failed to adjust their ordering practices in light of evolving scientific and professional organization recommendations. PMID:24392247

Cohen, David A.; Shirts, Brian H.; Jackson, Brian R.; Parker, Lisa S.

2013-01-01

72

Association between MTHFR C677T and A1298C, and MTRR A66G polymorphisms and susceptibility to schizophrenia in a Syrian study cohort.  

PubMed

The folate-homocystiene metabolic pathway has been shown to be involved in the susceptibility for developing schizophrenia by several studies. In the present study we investigated the role of three common polymorphisms of the folate-homocysteine metabolic pathway in an Arab population from Syria consisting of 85 schizophrenic patients and 126 healthy controls. The studied polymorphisms included the MTHFR C677T and A1298C, and MTRR A66G, all of which result into amino acid changes, and were previously shown to yield decreased enzymatic activity and alter plasma homocysteine concentration. While MTHFR C677T and A1298C polymorphisms were not previously studied in an Arab population with respect to the susceptibility for developing schizophrenia, the MTRR A66G was not previously investigated in any population around the world. Our results indicated a strong association between MTHFR A1298C and schizophrenia. The variant C allele frequency was significantly higher in the patients group (40% vs 29.4%, OR=1.6, 95% CI (1.06-2.41), p=0.023). A statistically significant association was found for MTHFR 677TT genotype under the recessive model in the male patients subgroup (OR=2.6, 95% CI (1.04-6.5), p=0.036), and MTHFR 677CT genotype under the overdominant model in the total patients group (OR=0.52 95% CI (0.29-0.92), p=0.024). No statistically significant association was found for MTRR A66G polymorphism on an individual basis. However, a borderline association was found for the CC/GG (C677T/A66G) compound genotype (OR=2.24, 95% CI (0.97-5.15), p=0.053). Our results support the hypothesis of association between schizophrenia and folate-homocystiene metabolic pathway genes. PMID:22813657

Lajin, Bassam; Alhaj Sakur, Amir; Michati, Roula; Alachkar, Amal

2012-06-01

73

Methylenetetrahydrofolate reductase C677T and overall survival in pediatric acute lymphoblastic leukemia: a systematic review.  

PubMed

A summary of the evidence pertaining to the association between methylenetetrahydrofolate reductase (MTHFR) C677T and overall survival in pediatric acute lymphoblastic leukemia (ALL) is not currently available. We thus reviewed the literature on the association between MTFHR C677T and overall survival in pediatric ALL. We searched PubMed/MEDLINE, Scopus and ISI Web of Knowledge literature databases without language restrictions to identify observational studies among children diagnosed between ages 0 and 19 years that assessed MTHFR 677 polymorphisms in relation to ALL survival. We identified six studies comprising 909 pediatric patients with ALL. The magnitude of relative risk (RR) for pediatric ALL mortality varied by genotype comparison and study population, ranging from RR = 0.84 (95% confidence limits [CL]: 0.24, 3.0) for a TT vs. CT/CC comparison to RR = 7.0 (95% CL: 0.98, 49) for a TT vs. CC comparison. The current evidence suggests that individuals with MTHFR 677 variants (i.e. at least one T allele) may have a higher relative risk of pediatric ALL mortality, with greater statistical support for MTHFR 677TT. With more detailed supporting evidence, MTHFR 677 genotyping at diagnosis could provide an option for individualizing therapy and further reducing pediatric ALL mortality in certain populations. PMID:23550988

Ojha, Rohit P; Gurney, James G

2014-01-01

74

No association between MTHFR C677T polymorphism and completed suicide.  

PubMed

MTHFR C677T polymorphism (rs1801133) was associated with numerous psychiatric conditions but no prior study investigated whether it predisposes to completed suicide. We typed rs1801133 in 692 suicide victims and 3257 controls representative of a Polish adult population (the WOBASZ cohort). Although we had a power of 0.8 to detect (at alpha 0.05) an allelic OR=1.19, we did not find significant difference among suicides vs. controls in the prevalence of the MTHFR 677T allele (OR=1.02, p=0.759) or the TT genotype (OR=1.01, p=0.926). Since among controls we found an association between TT and depression defined by Beck Depression Inventory (BDI, OR=1.61, p=0.049) we also compared suicides with controls without signs of depression (BDI ? 11) but found no association (OR=1.0, p=0.976). Analyses within suicides showed trends (not significant after Bonferroni correction) for correlations between the dose of the T allele and age at death among males and blood ethanol concentration among females, who committed suicide under the influence of alcohol. We conclude that MTHFR C677T polymorphism is not a risk factor for completed suicide. The sex-specific trends for correlations between rs1801133 and age at death, and blood ethanol concentration should be studied further. PMID:22982411

Chojnicka, Izabela; Sobczyk-Kopcio?, Agnieszka; Fudalej, Marcin; Fudalej, Sylwia; Wojnar, Marcin; Wa?kiewicz, Anna; Broda, Gra?yna; Strawa, Katarzyna; Pawlak, Aleksandra; Krajewski, Pawe?; P?oski, Rafa?

2012-12-10

75

Influence of Methylenetetrahydrofolate Reductase C677T, A1298C, and G80A Polymorphisms on the Survival of Pediatric Patients with Acute Lymphoblastic Leukemia  

PubMed Central

The influence of genic polymorphisms involved in metabolism of chemotherapeutic agents as the methotrexate (MTX) has been studied mainly in acute lymphoblastic leukemia (ALL) of childhood. Advances in treatment may be attributed to identification of prognostic factors added to chemotherapy protocol. The aim of this study was to analyze the association of the C677T, A1298C, and G80A polymorphisms on MTHFR gene and on the overall survival of pediatric patients (n = 126) with lymphoblastic leukemia treated with MTX according to the Brazilian protocol in 187 months. The C677T and G80A polymorphisms were genotyped by PCR-RFLP and A1298C polymorphism by allele-specific PCR. We observed that ALL patients presented rate (dead/alive) of 0.36 for the 677CC genotype, corresponding also to lower overall survival (P = 0.0013); on the other hand, the 677TT genotype showed a better survival (98%). Thus, we believe that patients with 80AA genotype presented a small reduction in MTX plasma level, suggesting that ALL children, carrying the 80AA genotype, showed a high toxicity to MTX (P < 0.0001). PMID:23198157

de Deus, Dayse Maria Vasconcelos; de Lima, Elker Lene Santos; Seabra Silva, Rafaela Maria; Leite, Edinalva Pereira; Cartaxo Muniz, Maria Tereza

2012-01-01

76

ABSENCE OF FACTOR V A RG306?THR AND LOW FACTOR V ARG306?GLY MUTATION PREVALENCE IN THAI BLOOD DONORS  

Microsoft Academic Search

Thrombosis among the Thai population is much lower than in western countries. The Thai population is protected to some extent against familial thrombophilia as by the very low prevalence of factor V Leiden, G20210A prothrombin and C677T methylenetetrahydrofolate reductase mutations. The present study reports the prevalence of two mutations of the factor V gene involving the codon for Arg 306

Ampaiwan Chuansumrit; Wasana Jarutwachirakul; Werasak Sasanakul; Saranya Rurgkhum; Praguywan Kadegasem; Pimpan Kitpoka; Nongnuch Sirachainan

77

Association of methylenetetrahydrofolate reductase C677T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations  

PubMed Central

Background The association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and serum lipid profiles is still controversial in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. The aim of the present study was to eveluate the association of MTHFR C677T polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations. Methods A total of 780 subjects of Bai Ku Yao and 686 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the MTHFR C677T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. Results The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05-0.001). The frequency of C and T alleles was 77.4% and 22.6% in Bai Ku Yao, and 60.9% and 39.1% in Han (P < 0.001); respectively. The frequency of CC, CT and TT genotypes was 58.7%, 37.3% and 4.0% in Bai Ku Yao, and 32.6%, 56.4% and 11.0% in Han (P < 0.001); respectively. The levels of TC and LDL-C in both ethnic groups were significant differences among the three genotypes (P < 0.05-0.01). The T allele carriers had higher serum TC and LDL-C levels than the T allele noncarriers. The levels of ApoB in Han were significant differences among the three genotypes (P < 0.05). The T allele carriers had higher serum ApoB levels as compared with the T allele noncarriers. The levels of TC, TG and LDL-C in Bai Ku Yao were correlated with genotypes (P < 0.05-0.001), whereas the levels of LDL-C in Han were associated with genotypes (P < 0.001). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, cigarette smoking, and blood pressure in the both ethnic groups. Conclusions The differences in serum TC, TG, LDL-C and ApoB levels between the two ethnic groups might partly result from different genotypic and allelic frequencies of the MTHFR C677T or different MTHFR gene-enviromental interactions. PMID:20977771

2010-01-01

78

Hyperhomocysteinemia and methylenetetrahydrofolate reductase C677T polymorphism in cerebral veno-sinus thrombosis.  

PubMed

There is limited data on the role of hyperhomocysteinemia as a risk factor for cerebral veno-sinus thrombosis (CVT) in Indians. We examined the association between plasma homocysteine (Hcy), methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism, and CVT in 185 patients with aseptic CVT (puerperal 80 and nonpuerperal 105) and 248 healthy controls (puerperal 67 and nonpuerperal 181). Fasting Hcy was higher in patients compared to controls (20.25 ± 5.97 vs 9.81 ± 5.19 ?mol/L, P < .001) and associated with 4.54-fold (95% confidence interval [CI]: 2.74-7.53) increase in risk of CVT. Risk was higher in puerperal (odds ratio [OR]: 8.7, 95% CI: 2.73-26.91) compared to nonpuerperal CVT (OR: 3.82, 95% CI: 2.09-6.96). Plasma Hcy was higher in MTHFR 677TT compared to 677CT and 677CC genotypes (34.44 ± 32.8 vs 25.81 ± 33.3 vs 18.50 ± 23.7 ?mol/L, respectively, P < .001), but the risk associated with MTHFR 677TT was insignificant (OR: 1.91, 95% CI: 0.53-7.06). We conclude that hyperhomocysteinemia is a risk marker for Indian patients with aseptic CVT. MTHFR 677TT genotype is not linked with CVT but is a determinant of plasma Hcy. PMID:23172871

Bharatkumar, Venkata Pinnelli; Nagaraja, Dindagur; Christopher, Rita

2014-01-01

79

Effects of Maternal 5,10-Methylenetetrahydrofolate Reductase C677T and A1298C Polymorphisms and Tobacco Smoking on Infant Birth Weight in a Japanese Population  

PubMed Central

Background Intracellular folate hemostasis depends on the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene. Because 5,10-MTHFR 677TT homozygosity and tobacco smoking are associated with low folate status, we tested the hypothesis that smoking in mothers with 5,10-MTHFR C677T or A1298C polymorphisms would be independently associated with lower birth weight among their offspring. Methods We assessed 1784 native Japanese mother-child pairs drawn from the ongoing birth cohort of The Hokkaido Study on Environment and Children’s Health. Data (demographic information, hospital birth records, and biological specimens) were extracted from recruitments that took place during the period from February 2003 to March 2006. Maternal serum folate were assayed by chemiluminescent immunoassay, and genotyping of 5,10-MTHFR C677T/A1298C polymorphisms was done using a TaqMan allelic discrimination assay. Results The prevalence of folate deficiency (<6.8 nmol/L) was 0.3%. The 5,10-MTHFR 677CT genotype was independently associated with an increase of 36.40 g (95% CI: 2.60 to 70.30, P = 0.035) in mean infant birth weight and an increase of 90.70 g (95% CI: 6.00 to 175.50, P = 0.036) among male infants of nonsmokers. Female infants of 677TT homozygous passive smokers were 99.00 g (95% CI: ?190.26 to ?7.56, P = 0.034) lighter. The birth weight of the offspring of smokers with 5,10-MTHFR 1298AA homozygosity was lower by 107.00 g (95% CI: ?180.00 to ?33.90, P = 0.004). Conclusions The results suggest that, in this population, maternal 5,10-MTHFR C677T polymorphism, but not the 5,10-MTHFR A1298C variant, is independently associated with improvement in infant birth weight, especially among nonsmokers. However, 5,10-MTHFR 1298AA might be associated with folate impairment and could interact with tobacco smoke to further decrease birth weight. PMID:22277790

Yila, Thamar Ayo; Sasaki, Seiko; Miyashita, Chihiro; Braimoh, Titilola Serifat; Kashino, Ikuko; Kobayashi, Sumitaka; Okada, Emiko; Baba, Toshiaki; Yoshioka, Eiji; Minakami, Hisanori; Endo, Toshiaki; Sengoku, Kazuo; Kishi, Reiko

2012-01-01

80

Livedoid vasculopathy associated with combined prothrombin G20210A and factor V (Leiden) heterozygosity and MTHFR C677T homozygosity.  

PubMed

Livedoid vasculopathy (LV) is an occlusive thrombotic disease of lower extremities. A 34-year-old woman presented with 4-year history of recurrent necrotic and painful lesions with violaceous and purpuric border on both legs. Initial treatment with hydroxychloroquine, dapsone and prednisone were unsuccessful. Skin biopsy showed inflammatory infiltrate with epidermal necrosis. Prothrombin G20210A and factor V-Leiden heterozygosity, and MTHFR C677T homozygosity with hyperhomocysteinemia were confirmed. LV diagnosis was made; acetylsalicylic acid, folic acid, vitamin B12, and prednisone treatement resulted in complete healing. This is the first report on coexistence of prothrombin G20210A, factor V-Leiden, and homozygous MTHFR C677T with hyperhomocysteinemia in LV. PMID:18360788

Irani-Hakime, Noha A; Stephan, Farid; Kreidy, Raghid; Jureidini, Isabelle; Almawi, Wassim Y

2008-08-01

81

Population distribution of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C risk alleles for methotrexate toxicity in Israel.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is a central regulatory enzyme in the folate pathway. Two non-synonymous single nucleotide polymorphisms in MTHFR, C677T (rs1801133) and A1298C (rs1801131) have been associated with reduced MTHFR enzyme activity. These polymorphisms, especially C677T, appear to be linked with methotrexate-related toxicity, particularly hepatotoxicity; thus, pretreatment identification of individuals carrying these polymorphisms may be of clinical relevance. The purpose of this study was to determine the frequency and distribution of MTHFR polymorphic variants, known to functionally impair MTHFR activity, in the highly heterogeneous Israeli population. MTHFR genotyping was carried out in the representatives of three major demographic groups in Israel by PCR-restriction fragment length polymorphism and high-resolution melting. The relative distribution of variant alleles 677T and 1298C was found to be similar in individuals of Jewish, Druze and Arab Moslem descent (p = 0.09). However, Ashkenazi Jews displayed a 1.9-fold higher frequency of variant 677T and a 1.8-fold lower frequency of variant 1298C compared to non-Ashkenazi Jews (p < 0.001). Distinct differences in the relative frequencies of both polymorphisms were also found between Ashkenazi Jews and Druze (p < 0.01 for C677T, p < 0.01 for A1298C) or Ashkenazi Jews and Arab Moslem (p < 0.01 for C677T, p < 0.05 for A1298C). These data underscore the importance of geographic genetic analysis for a better understanding of human pharmacotherapy and personalized medicine. PMID:22847291

Efrati, Edna; Elkin, Hela; Nahum, Sagi; Krivoy, Norberto

2013-04-01

82

Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls  

PubMed Central

BACKGROUND Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden,FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. METHODS We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). RESULTS We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95% confidence intervals [CI]: 0.98–1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR=4.22; 95% CI: 3.35–5.32; and OR=2.79;95% CI: 2.25–3.46, respectively), in double hterozygotes (OR=3.42; 95%CI 1.64-7.13), and in homozygous FVL or PT20210A (OR=11.45; 95%CI: 6.79-19.29; and OR: 2.79; 95%CI: 2.25 – 3.46, respectively). The stratified analyses showed a stronger effect of FVL on individuals ?45 years (p-value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). CONCLUSIONS In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought. PMID:23900608

Simone, B; De Stefano, V; Leoncini, E; Zacho, J; Martinelli, I; Emmerich, J; Rossi, E; Folsom, AR; Almawi, WY; Scarabin, PY; den Heijer, M; Cushman, M; Penco, S; Vaya, A; Angchaisuksiri, P; Okumus, G; Gemmati, D; Cima, S; Akar, N; Oguzulgen, KI; Ducros, V; Lichy, C; Fernandez-Miranda, C; Szczeklik, A; Nieto, JA; Torres, JD; Le Cam-Duchez, V; Ivanov, P; Cantu, C; Shmeleva, VM; Stegnar, M; Ogunyemi, D; Eid, SS; Nicolotti, N; De Feo, E; Ricciardi, W; Boccia, S

2014-01-01

83

Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls.  

PubMed

Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden, FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95 % confidence intervals [CI]: 0.98-1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR = 4.22; 95 % CI: 3.35-5.32; and OR = 2.79;95 % CI: 2.25-3.46, respectively), in double heterozygotes (OR = 3.42; 95 %CI 1.64-7.13), and in homozygous FVL or PT20210A (OR = 11.45; 95 %CI: 6.79-19.29; and OR: 6.74 (CI 95 % 2.19-20.72), respectively). The stratified analyses showed a stronger effect of FVL on individuals ? 45 years (p value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought. PMID:23900608

Simone, Benedetto; De Stefano, Valerio; Leoncini, Emanuele; Zacho, Jeppe; Martinelli, Ida; Emmerich, Joseph; Rossi, Elena; Folsom, Aaron R; Almawi, Wassim Y; Scarabin, Pierre Y; den Heijer, Martin; Cushman, Mary; Penco, Silvana; Vaya, Amparo; Angchaisuksiri, Pantep; Okumus, Gulfer; Gemmati, Donato; Cima, Simona; Akar, Nejat; Oguzulgen, Kivilcim I; Ducros, Véronique; Lichy, Christoph; Fernandez-Miranda, Consuelo; Szczeklik, Andrzej; Nieto, José A; Torres, Jose Domingo; Le Cam-Duchez, Véronique; Ivanov, Petar; Cantu-Brito, Carlos; Shmeleva, Veronika M; Stegnar, Mojka; Ogunyemi, Dotun; Eid, Suhair S; Nicolotti, Nicola; De Feo, Emma; Ricciardi, Walter; Boccia, Stefania

2013-08-01

84

Subacute methotrexate neurotoxicity and cerebral venous sinus thrombosis in a 12-year-old with acute lymphoblastic leukemia and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism: homocysteine-mediated methotrexate neurotoxicity via direct endothelial injury.  

PubMed

From as early as the 1970s methotrexate has been associated with disseminated necrotizing leukoencephalopathy and other neurotoxic sequelae. Yet, a clear mechanism for methotrexate-induced neurotoxicity has not been established. The authors describe the case of a 12-year-old male with acute lymphoblastic leukemia and a homozygous methylenetetrahydrofolate reductase C677T mutation, who developed subacute methotrexate-induced toxicity and cerebral venous thrombosis after receiving intrathecal methotrexate. The role of homocysteine as a possible mediator in methotrexate-induced neurotoxicity via direct endothelial injury is discussed. PMID:20121554

Mahadeo, Kris M; Dhall, Girish; Panigrahy, Ashok; Lastra, Carlos; Ettinger, Lawrence J

2010-02-01

85

Maternal Methylenetetrahydrofolate Reductase C677T Polymorphism and Down Syndrome Risk: A Meta-Analysis from 34 Studies  

PubMed Central

Background Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of folate metabolic pathway which catalyzes the irreversible conversion of 5, 10-methylenetetrahydrofolate to 5-methyltetrahydrofolate. 5-methyltetrahydrofolate donates methyl group for the methylation of homocysteine to methionine. Several studies have investigated maternal MTHFR C677T polymorphism as a risk factor for DS, but the results were controversial and inconclusive. To come into a conclusive estimate, authors performed a meta-analysis. Aim A meta-analysis of published case control studies was performed to investigate the association between maternal MTHFR C677T polymorphism and Down syndrome. Methods PubMed, Google Scholar, Elsevier, Springer Link databases were searched to select the eligible case control studies using appropriate keywords. The pooled odds ratio (OR) with 95%confidence interval were calculated for risk assessment. Results Thirty four studies with 3,098 DS case mothers and 4,852 control mothers were included in the present meta-analysis. The pooled OR was estimated under five genetic models and significant association was found between maternal MTHFR 677C>T polymorphism and Down syndrome under four genetic models except recessive model (for T vs. C, OR?=?1.26, 95% CI?=?1.09–1.46, p?=?0.001; for TT vs. CC, OR?=?1.49, 95% CI?=?1.13–1.97, p?=?0.008; for CT vs. CC, OR?=?1.29, 95% CI?=?1.10–1.51, p?=?0.001; for TT+CT vs. CC, OR?=?1.35, 95% CI?=?1.13–1.60, p?=?0.0008; for TT vs. CT+CC, OR?=?0.76, 95% CI?=?0.60–0.94, p?=?0.01). Conclusion The results of the present meta-analysis support that maternal MTHFR C677T polymorphism is a risk factor for DS- affected pregnancy. PMID:25265565

Rai, Vandana; Yadav, Upendra; Kumar, Pradeep; Yadav, Sushil Kumar; Mishra, Om Prakesh

2014-01-01

86

Adaptive developmental plasticity in methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism limits its frequency in South Indians.  

PubMed

Methylene tetrahydrofolate reductase (MTHFR) C677T polymorphism shows considerable heterogeneity in its distribution in humans worldwide. The current study was conducted to investigate whether this polymorphism exhibited adaptive developmental plasticity in the control of the TT-genotype frequency. We screened 1,818 South Indian subjects (895 males and 923 females) for MTHFR C677T polymorphism using PCR-restriction fragment length polymorphism approach. MTHFR 677T-allele frequency in males and females was 9.1 and 11.0%, respectively. Compared to females, males had lower frequency of TT-genotype [odds ratio 0.31, 95% confidence interval (CI) 0.08-1.01]. The frequency of MTHFR 677T-allele was highest in the age group of 20-40 years and it gradually decreased from 40-60 to 60-80 years (P trend<0.0001). MTHFR 677TT-genotype was associated with 7.02-folds (95% CI: 2.12-25.63, P<0.0001) cumulative risk for recurrent pregnancy loss (RPL), neural tube defects (NTDs) and deep vein thrombosis (DVT). Linear regression model suggested that male gender exhibited increased homocysteine levels by 9.35 ?mol/L while each MTHFR 677T-allele contributed to 4.63 ?mol/L increase in homocysteine. Plasma homocysteine showed inverse correlation with dietary folate (r=-0.17, P<0.0001), B2 (r=-0.14, P<0.0001) and B6 (r=-0.07, P=0.03). Examination of the spontaneously aborted fetuses (n=35) showed no significant association of fetal genotype on its in utero viability. From the current study, it was concluded that C677T seemed to have acquired adaptive developmental plasticity among South Indians due to environmental influences thus contributing to hyperhomocysteinemia and its associated complications such as RPL, NTDs, DVT, etc. PMID:24449370

Naushad, Shaik Mohammad; Krishnaprasad, Chintakindi; Devi, Akella Radha Rama

2014-05-01

87

Cardiometabolic risk and the MTHFR C677T variant in children treated with second-generation antipsychotics.  

PubMed

Second-generation antipsychotics (SGAs) are increasingly being used to treat children with a variety of psychiatric illnesses. Metabolic syndrome (MetS), a risk factor for cardiovascular disease, is a side-effect of SGA-treatment. We conducted a cross-sectional study and assessed the association of the methylenetetrahydrofolate reductase (MTHFR) C677T variant with features of MetS in SGA-treated (n=105) and SGA-naïve (n=112) children. We targeted the MTHFR C677T variant, because it is associated with risk for cardiovascular disease, and features of MetS in adults without psychiatric illness. MetS in children is based on the presence of any three of the following: waist circumference ? 90th percentile for age and sex; plasma triglyceride ? 1.24?mmol?l(-1); plasma high-density lipoprotein-cholesterol ? 1.03?mmol?l(-1); systolic or diastolic blood pressure ? 90th percentile for age, sex, and height; and fasting glucose ? 5.6?mmol?l(-1). We found that 15% of SGA-treated children had MetS compared with 2% of SGA-naïve children (OR 8.113, P<0.05). No effect of the MTHFR C677T variant on psychiatric diagnosis was observed. The MTHFR 677T allele was associated (P<0.05) with MetS (OR 5.75, 95% CI= 1.18-28.12) in SGA-treated children. Models adjusted for duration of SGA treatment, ethnicity, sex, age and use of other medications revealed a positive relationship between the MTHFR 677T allele and diastolic blood pressure Z-scores (P=0.001) and fasting plasma glucose (P<0.05) in SGA-treated children. These findings illustrate the high prevalence of MetS in SGA-treated children and suggest metabolic alterations associated with the MTHFR C677T variant may have a role in the development of MetS features in SGA-treated children. PMID:22832733

Devlin, A M; Ngai, Y F; Ronsley, R; Panagiotopoulos, C

2012-01-01

88

Cardiometabolic risk and the MTHFR C677T variant in children treated with second-generation antipsychotics  

PubMed Central

Second-generation antipsychotics (SGAs) are increasingly being used to treat children with a variety of psychiatric illnesses. Metabolic syndrome (MetS), a risk factor for cardiovascular disease, is a side-effect of SGA-treatment. We conducted a cross-sectional study and assessed the association of the methylenetetrahydrofolate reductase (MTHFR) C677T variant with features of MetS in SGA-treated (n=105) and SGA–naïve (n=112) children. We targeted the MTHFR C677T variant, because it is associated with risk for cardiovascular disease, and features of MetS in adults without psychiatric illness. MetS in children is based on the presence of any three of the following: waist circumference ?90th percentile for age and sex; plasma triglyceride ?1.24?mmol?l?1; plasma high-density lipoprotein-cholesterol ?1.03?mmol?l?1; systolic or diastolic blood pressure ?90th percentile for age, sex, and height; and fasting glucose ?5.6?mmol?l?1. We found that 15% of SGA-treated children had MetS compared with 2% of SGA-naïve children (OR 8.113, P<0.05). No effect of the MTHFR C677T variant on psychiatric diagnosis was observed. The MTHFR 677T allele was associated (P<0.05) with MetS (OR 5.75, 95% CI= 1.18–28.12) in SGA-treated children. Models adjusted for duration of SGA treatment, ethnicity, sex, age and use of other medications revealed a positive relationship between the MTHFR 677T allele and diastolic blood pressure Z-scores (P=0.001) and fasting plasma glucose (P<0.05) in SGA-treated children. These findings illustrate the high prevalence of MetS in SGA-treated children and suggest metabolic alterations associated with the MTHFR C677T variant may have a role in the development of MetS features in SGA-treated children. PMID:22832733

Devlin, A M; Ngai, Y F; Ronsley, R; Panagiotopoulos, C

2012-01-01

89

Polymorphisms of MTHFR C677T and A1298C association with oral carcinoma risk: a meta-analysis.  

PubMed

Investigations regarding association of MTHFR polymorphisms with oral carcinoma risk have yielded inconclusive results. Thus, meta-analyses were performed. Results showed that no associations of C677T polymorphisms with oral carcinoma were observed for the overall data. In subgroup analyses by drinking status, homozygous TT alleles exhibited elevated oral cancer susceptibility in heavy drinkers. For A1298C polymorphism, CC alleles presented a possible preventive role for oral cancer. Collectively, results suggest that MTHFR 677TT polymorphism might be a low-penetrant risk factor for oral carcinoma only in heavy drinkers. Conversely, 1298CC alleles might play a preventive role for oral cancer. PMID:22536935

Zhuo, Xianlu; Ling, Junjun; Zhou, Yan; Zhao, Houyu; Song, Yufeng; Tan, Yinghui

2012-07-01

90

MTHFR C677T and A1298C Genotypes and Haplotypes in Slovenian Couples with Unexplained Infertility Problems and in Embryonic Tissues from Spontaneous Abortions  

PubMed Central

The objective of this study was to analyze the methylenetetrahydrofolate reductases ( MTHFR s) C677T and A1298C genotype distributions in couples with unexplained fertility problems (UFP) and healthy controls, and to analyze the genotype and haplotype distribution in spontaneously aborted embryonic tissues (SAET) using allele specific polymerase chain reaction (PCR) in 200 probands with UFP, 353 samples of SAET and 222 healthy controls. The analysis revealed a significant overall representation of the 677T allele in male probands from couples with UFP ( p = 0.036). The combined genotype distribution for both MTHFR polymorphisms was also significantly altered (? 2 21.73, p <0.001) although female probands made no contribution (? 2 1.33, p = 0.72). The overall representation of the 677T allele was more pronounced in SAET (0.5 vs. 0.351 in controls, p <0.001) regardless of the karyotype status (aneuploidy vs. normal karyotype). In addition, the frequencies of the CA and CC haplotypes were significantly lower than in the control group ( p = 0.021 and p = 0.001, respectively), whereas the frequency of the TC haplotype was significantly higher than in controls ( p <0.0001). The presented findings indicate that only male probands contribute to the association of MTHFR mutations with fertility problems in grown adults and demonstrate a high prevalence of mutated MTHFR genotypes in SAET. PMID:24265582

Stangler Herodež, Š; Zagradišnik, B; Erjavec Škerget, A; Zagorac, A; Taka?, I; Vlaisavljevi?, V; Lokar, L; Kokalj Voka?, N

91

Association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma susceptibility: evidence from a meta-analysis.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is an important enzyme involved in folate metabolism and DNA synthesis. A number of studies have examined the association of MTHFR C677T and A1298C polymorphisms with non-Hodgkin lymphoma (NHL) susceptibility; however, the conclusions were contradictory. We searched available publications assessing the polymorphisms of MTHFR and NHL susceptibility from MEDLINE, EMBASE and CBM. Genotype-based mRNA expression analysis was performed using data from 270 individuals with three different ethnicities. Ultimately, a total of 7448 cases and 11146 controls from 25 studies were included for the C677T polymorphism, 6173 cases and 9725 controls from 19 studies for the A1298C polymorphism. Pooled results indicated that neither C677T nor A1298C polymorphism was associated with NHL susceptibility. However, C677T polymorphism showed a statistically significantly increased risk for Caucasians, but a decreased risk for Asians in the subgroup analysis by ethnicity. The same variants may confer increased susceptibility to develop follicular lymphoma (FL). Moreover, A1298C polymorphism was associated with increased NHL risk for Asians. This meta-analysis indicated that C677T polymorphism was associated with altered NHL susceptibility for Caucasians, Asians and FL. Increased NHL risk was also shown for A1298C among Asians. These findings warrant validation in large and well-designed prospective studies. PMID:25146845

He, Jing; Liao, Xiao-Yu; Zhu, Jin-Hong; Xue, Wen-Qiong; Shen, Guo-Ping; Huang, Shao-Yi; Chen, Wei; Jia, Wei-Hua

2014-01-01

92

Association of methylenetetrahytrofolate reductase (MTHFR) C677T and A1298C polymorphisms with the susceptibility of childhood acute lymphoblastic leukaemia (ALL) in Chinese population  

PubMed Central

Background The aim of this study was to investigate the relationship between the polymorphisms of the methylenetetrahytrofolate reductase (MTHFR) gene and susceptibility to childhood acute lymphoblastic leukemia (ALL). Methods A case–control study was conducted among 98 children with ALL and 93 age- and sex- matched non-ALL controls. Genotyping of MTHFR C677T and A1298C polymorphisms was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The odds ratios (ORs) of MTHFR genotypes were used to assess the associations of these polymorphisms with childhood ALL susceptibility. Results No significant differences were observed for frequencies of the 677CC, 677CT and 677TT genotypes between patients and controls. Frequencies of the 1298AA, 1298 AC and 1298CC genotypes between the two groups were significantly different. The risk of ALL with the 1298C allele carriers (AC?+?CC) was elevated by 1.1 times compared with the AA genotype [OR?=?2.100; 95% CI (1.149; 3.837); P?=?0.015]. Conclusions The MTHFR A1298C polymorphism is associated with susceptibility to childhood ALL in the Chinese population. PMID:24476575

2014-01-01

93

Quantitative assessment of the associations between MTHFR C677T and A1298C polymorphisms and risk of fractures: a meta-analysis.  

PubMed

Many studies have investigated the associations between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and risk of fractures, but the impact of MTHFR polymorphisms on fractures risk is unclear owing to the obvious inconsistence among those studies. This study aims to quantify the strength of association between MTHFR C677T and A1298C polymorphisms and risk of fractures. We searched the PubMed, Embase and Wanfang databases for articles relating the association between MTHFR C677T and A1298C polymorphisms and risk of fractures in humans. We estimated summary odds ratios (ORs) with their confidence intervals (CIs) to assess the associations. Meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of any site fractures (for T vs. C, OR = 1.17, 95 % CI 1.03-1.32; for TT vs. CC, OR = 1. 31, 95 % CI 1.11-1.54; for TT vs. CT, OR = 1.22, 95 % CI 1.04-1.43; for TT vs. CT/CC, OR = 1.31, 95 % CI 1.13-1.51). Besides, MTHFR A1298C polymorphism was also associated with increased risk of any site fractures. Subgroup meta-analyses suggested MTHFR C677T polymorphism was associated with increased risk of vertebral fractures under three genetic contrast modes (for TT vs. CC, OR = 1.43, 95 % CI 1.05-1.95; for TT vs. CT, OR = 1.36, 95 % CI 1.01-1.85; for TT vs. CT/CC, OR = 1.50, 95 % CI 1.17-1.91), but there was no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures (all P values were more than 0.05). Thus, individuals with homozygote genotype TT of MTHFR C677T have obviously increased risk of vertebral fractures compared those with heterozygote genotype CT or homozygote genotype CC. There is no association between MTHFR C677T polymorphism and risk of hip fractures and non-vertebral fractures. PMID:23229495

Bai, Rui; Liu, Wanlin; Zhao, Aiqing; Zhao, Zhenqun; Jiang, Dianming

2013-03-01

94

Meta-analyses of Blood Homocysteine Levels for Gender and Genetic Association Studies of the MTHFR C677T Polymorphism in Schizophrenia  

PubMed Central

Previous studies suggest that elevated blood homocysteine levels and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism are risk factors for schizophrenia. However, the effects of gender and MTHFR C677T genotypes on blood homocysteine levels in schizophrenia have not been consistent. We first investigated whether plasma total homocysteine levels were higher in patients with schizophrenia than in controls with stratification by gender and by the MTHFR C677T genotypes in a large cohort (N = 1379). Second, we conducted a meta-analysis of association studies between blood homocysteine levels and schizophrenia separately by gender (N = 4714). Third, we performed a case-control association study between the MTHFR C677T polymorphism and schizophrenia (N = 4998) and conducted a meta-analysis of genetic association studies based on Japanese subjects (N = 10 378). Finally, we assessed the effect of plasma total homocysteine levels on schizophrenia by a mendelian randomization approach. The ANCOVA after adjustment for age demonstrated a significant effect of diagnosis on the plasma total homocysteine levels in all strata, and the subsequent meta-analysis for gender demonstrated elevated blood homocysteine levels in both male and female patients with schizophrenia although antipsychotic medication might influence the outcome. The meta-analysis of the Japanese genetic association studies demonstrated a significant association between the MTHFR C677T polymorphism and schizophrenia. The mendelian randomization analysis in the Japanese populations yielded an OR of 1.15 for schizophrenia per 1-SD increase in plasma total homocysteine. Our study suggests that increased plasma total homocysteine levels may be associated with an increased risk of schizophrenia. PMID:24535549

Nishi, Akira; Numata, Shusuke; Tajima, Atsushi; Kinoshita, Makoto; Kikuchi, Kumiko; Shimodera, Shinji; Tomotake, Masahito; Ohi, Kazutaka; Hashimoto, Ryota; Imoto, Issei; Takeda, Masatoshi; Ohmori, Tetsuro

2014-01-01

95

MTHFR C677T and A1298C variant genotypes and the risk of microsatellite instability among Iranian colorectal cancer patients  

PubMed Central

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the folate metabolic pathway. We aimed to test the hypothesis that C677T and A1298C variants of MTHFR predispose to microsatellite instable (MSI) colorectal cancer. We determined MTHFR genotypes in 175 sporadic colorectal cancer patients and a total of 231 normal controls in Shiraz, Southern Iran. Among the genotypes found in our samples, MTHFR CT and CT + TT were associated with increased risk for CRC incidence [odds ratio (OR) = 2.4, 95% confidence interval (95%CI) = 1.8–4.4; OR = 2.4, 95%CI = 1.6–3.6, respectively]. Double heterozygotes 677CT/1298AC and double homozygote 677TT/1298AA and 677CC/1298CC genotypes also showed a significantly increased risk of developing CRC compared with the wild-type 677CC/1298AA genotypes of the controls. Among the 151 tumors tested, 36 (23.8%) were MSI+. MSI was more common in proximal tumors (OR = 10.4; 95%CI = 3.9–27.8) and in smokers (OR = 2.9; 95%CI = 1.3–6.7). In a case–control comparison, the MTHFR 677CT + TT genotype was strongly associated with MSI (OR = 2.6; 95%CI = 1.3–5.3). Hypermethylation of mismatch repair genes was positively related with MSI incidence in these tumor series (P = 0.00). Our data suggest that the MTHFR 677CT + TT variant genotype may be a risk factor for MSI+ cancer. PMID:20193847

Naghibalhossaini, Fakhraddin; Mokarram, Pooneh; Khalili, Islam; Vasei, Mohammad; Hosseini, Seyed Vahid; Ashktorab, Hassan; Rasti, Mozhgan; Abdollahi, Kourosh

2013-01-01

96

MTHFR C677T and A1298C variant genotypes and the risk of microsatellite instability among Iranian colorectal cancer patients.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in the folate metabolic pathway. We aimed to test the hypothesis that C677T and A1298C variants of MTHFR predispose to microsatellite instable (MSI) colorectal cancer. We determined MTHFR genotypes in 175 sporadic colorectal cancer patients and a total of 231 normal controls in Shiraz, Southern Iran. Among the genotypes found in our samples, MTHFR CT and CT+TT were associated with increased risk for CRC incidence [odds ratio (OR)=2.4, 95% confidence interval (95%CI)=1.8-4.4; OR=2.4, 95%CI=1.6-3.6, respectively]. Double heterozygotes 677CT/1298AC and double homozygote 677TT/1298AA and 677CC/1298CC genotypes also showed a significantly increased risk of developing CRC compared with the wild-type 677CC/1298AA genotypes of the controls. Among the 151 tumors tested, 36 (23.8%) were MSI+. MSI was more common in proximal tumors (OR=10.4; 95%CI=3.9-27.8) and in smokers (OR=2.9; 95%CI=1.3-6.7). In a case-control comparison, the MTHFR 677CT+TT genotype was strongly associated with MSI (OR=2.6; 95%CI=1.3-5.3). Hypermethylation of mismatch repair genes was positively related with MSI incidence in these tumor series (P=0.00). Our data suggest that the MTHFR 677CT+TT variant genotype may be a risk factor for MSI+ cancer. PMID:20193847

Naghibalhossaini, Fakhraddin; Mokarram, Pooneh; Khalili, Islam; Vasei, Mohammad; Hosseini, Seyed Vahid; Ashktorab, Hassan; Rasti, Mozhgan; Abdollahi, Kourosh

2010-03-01

97

Methylenetetrahydrofolate Reductase C677T Polymorphism and Type 2 Diabetes Mellitus in Chinese Population: A Meta-Analysis of 29 Case-Control Studies  

PubMed Central

Background Methylenetetrahydrofolate reductase (MTHFR), a key enzyme in folate metabolism, had significant effects on the homocysteine levels. The common functional MTHFR C677T polymorphism had been extensively researched. Several studies had evaluated the relationship between MTHFR C677T polymorphism and type 2 diabetes mellitus (T2DM), but the results were still controversial in the Chinese Han population. This meta-analysis was conducted to evaluate the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. Methods We searched the relevant studies in multiple electronic databases, which published up to December 2013. We reviewed and extracted data from all the included studies on the relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The odds ratios (ORs) and their 95% confidence intervals (95%CIs) were used to evaluate the relationship. Fixed-effects and random-effects meta-analysis were used to pool ORs by the heterogeneity. Publication bias and sensitivity analysis were also examined. Results 29 studies were finally included in our meta-analysis, which contained 4656 individuals with T2DM and 2127 healthy controls. There was a significant relationship between MTHFR C677T polymorphism and T2DM under dominant (OR: 1.70, 95% CI: 1.42–2.02), recessive (OR: 1.48, 95% CI: 1.21–1.80), homozygous (OR: 1.89, 95% CI: 1.47–2.42), heterozygous (OR: 1.58, 95% CI: 1.33–1.87), and additive (OR: 1.46, 95% CI: 1.28–1.68) genetic model in a random-effects model. Subgroup analysis also reached similar results. Sensitivity analysis indicated that the overall result were dependable. Conclusions There was a significant relationship between MTHFR C677T polymorphism and T2DM in the Chinese Han population. The results of our meta-analysis suggested that MTHFR 677T allele might be a risk genetic factor of T2DM in the Chinese Han population. PMID:25047451

Zhu, Bo; Wu, Xiaomei; Zhi, Xueyuan; Liu, Lei; Zheng, Quanmei; Sun, Guifan

2014-01-01

98

Prevalence of thromogenic gene mutations in women with recurrent miscarriage: A retrospective study of 1,507 patients  

PubMed Central

Objective Thromogenic gene mutations has been thought to be associated with recurrent pregnancy loss in women in Turkey. The aim of this study was to investigate the prevalence of thromogenic gene mutations such as factor V Leiden (FVL, G1691T), prothrombin (G20210A), and the methylene tetrahydrofolate reductase (MTHFR, C677T) mutation in women with recurrent pregnancy loss. Methods This descriptive study was carried out in the Department of Obstetrics and Gynaecology, Harran University School of Medicine, and included a total of 1,507 women with histories of recurrent pregnancy loss between January 2010 and June 2013. The mutations were assessed by using the polymerase chain reaction. Results The homozygous mutation frequencies of FVL, prothrombin, and MTHFR were found to be 3 (0.20%), 0 and 125 (8.29%), and the heterozygous mutation frequencies were 83 (5.51%), 61 (4.05%), and 612 (40.61%), respectively. Among the 86 FVL mutation patients, 38 also had accompanying prothrombin and MTHFR mutations. Conclusion Since the homozygous forms of the FVL-prothrombin gene mutations have low incidences and MTHFR mutation is similar to a healthy population, preconceptional thromogenic gene mutations screening seems to be controversial. PMID:25469341

Hilali, Nese Gul; Camuzcuoglu, Aysun; Camuzcuoglu, Hakan; Akbas, Halit; Kilic, Avni; Vural, Mehmet

2014-01-01

99

Methylenetetrahydrofolate reductase C677T and A1298C polymorphism and changes in homocysteine concentrations in women with idiopathic recurrent pregnancy losses.  

PubMed

Because they have been described as strong risk factors for idiopathic recurrent pregnancy losses (RPLs), we assessed the association between the methylenetetrahydrofolate reductase (MTHFR) single-nucleotide polymorphisms (SNPs) C677T and A1298C and hyperhomocysteinemia in Tunisian women with idiopathic RPL. Study subjects comprised 200 patients with more than three consecutive RPLs, and 200 age-matched parous control women. C677T and A1298C SNPs were analyzed by PCR-RFLP analysis, and fasting serum homocysteine was measured with ELISA. The frequency of MTHFR 677T/T (30.0 vs 7.0%) and 1298C/C (13.5 vs 4.0%) genotypes was significantly higher in patients. While it was similar among patients and controls (P = 0.095), higher homocysteine was seen with the T/T (but not 1298A/C and 1298C/C) genotype among patients and controls compared with non-T/T carriers (P < 0.05), and in patients vs controls. Higher prevalence of MTHFR 677T/T was seen in late (P < 0.05) and early-late (P < 0.001) RPL, while higher prevalence of 1298C/C genotype was seen only in early-late RPL (P < 0.001), and the prevalence of double heterozygotes was statistically not significant between patients and controls (P = 0.10; odds ratio = 2.73). Logistic regression analysis showed that, after adjusting for all variables, homozygosity for MTHFR C677T was associated with late (P < 0.001), and combined early-late (P < 0.001), while homozygosity for A1298C was associated only with combined early-late (P = 0.026), as was secondary-level education, which was associated with early (P = 0.005), late (P = 0.026) and combined early-late (P = 0.004) abortions. Homozygosity for MTHFR C677T (late and early-late) and A1298C (early-late) are risk factor for RPLs, irrespectively of total homocysteine levels. PMID:16452733

Mtiraoui, N; Zammiti, W; Ghazouani, L; Braham, N Jmili; Saidi, S; Finan, R R; Almawi, W Y; Mahjoub, T

2006-02-01

100

Mendelian Randomization Analysis of the Effect of Maternal Homocysteine During Pregnancy, as Represented by Maternal MTHFR C677T Genotype, on Birth Weight  

PubMed Central

Background We used Mendelian randomization analysis to investigate the causal relationship between maternal homocysteine level, as represented by maternal methylenetetrahydrofolate reductase (MTHFR) C677T genotype, with the birth weight of offspring. Methods We recruited women at 24 to 28 weeks’ gestation who visited Ewha Womans University Hospital for prenatal care during the period from August 2001 to December 2003. A total of 473 newborns with a gestational age of at least 37 weeks were analyzed in this study. We excluded twin births and children of women with a history of gestational diabetes, gestational hypertension, or chronic renal disease. The association of maternal homocysteine concentration with the birth weight of infants was analyzed using 2-stage regression. Results MTHFR C677T genotype showed a dose–response association with homocysteine concentration for each additional T allele (Ptrend < 0.01). Birth weight decreased from 120 to 130 grams as maternal homocysteine level increased, while controlling for confounding factors; however, the association was of marginal significance (P = 0.06). Conclusions Our results suggest an adverse relationship between maternal homocysteine level and birth weight. A reduction in homocysteine levels might positively affect birth outcomes. PMID:23856949

Lee, Hye Ah; Park, Eun Ae; Cho, Su Jin; Kim, Hae Soon; Kim, Young Ju; Lee, Hwayoung; Gwak, Hye Sun; Kim, Ki Nam; Chang, Namsoo; Ha, Eun Hee; Park, Hyesook

2013-01-01

101

Association between MTHFR C677T and A1298C Polymorphisms and NSCL/P Risk in Asians: A Meta-Analysis  

PubMed Central

Objective Several studies have reported the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and nonsyndromic cleft lip with or without palate (NSCL/P) in Asian populations. However, findings have been conflicting. In order to investigate the association, a meta-analysis was performed. Methods We searched Pubmed, MedLine and EmBase database to selected eligible studies. The pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated using fixed effects model or random effects model to assess the association between MTHFR polymorphisms and NSCL/P in both Asian children and mothers. Results Finally, nine case-control studies were included. Overall, the MTHFR C677T polymorphism and NSCL/P showed pooled ORs (95%CI) of 1.41(1.23–1.61) in Asian children, and 1.70(1.19–2.42) in Asian mothers. Subgroup analyses by geographical locations further identified the association in Eastern Asian children, Western/Central Asian children and mothers, but not in Eastern Asian mothers. However, no significant relationship between MTHFR A1298C polymorphism and NSCL/P was found in this meta-analysis. Conclusions The MTHFR 677T allele was associated with an increased risk of NSCL/P in Asian populations. PMID:24658649

Zhao, Mengmeng; Ren, Yangwu; Shen, Li; Zhang, Yue; Zhou, Baosen

2014-01-01

102

Methylenetetrahydrofolate reductase gene mutations as risk factors for sudden hearing loss.  

PubMed

Sudden hearing loss (SHL) can be caused by vascular disorders favoring impaired cochlear perfusion. Several inherited prothrombotic risk factors have been considered in the pathogenesis of vascular impairment, and the possible role of genetic alterations has recently been suggested. Methylenetetrahydrofolate reductase (MTHFR) gene mutations at nucleotides 677 and 1298 cause reduced MTHFR enzyme activity, which leads to increased homocysteine and reduced serum folate levels that are known to be involved in vascular impairment. We studied the relationship between SHL and MTHFR C677T and A1298C gene polymorphisms in 67 patients with SHL and 134 controls. Wild-type MTHFR CC677/AA1298 was significantly more frequent in the controls (P = .05), and gene mutations were significantly more frequent in the patients (P = .001; P = .001 for trend). Fifty-three patients (79.1%) and 56 controls (41.8%) (P = .012) had a double mutation (homozygosis 677TT or 1298CC; compound heterozygosis for both polymorphisms). Homocysteine levels were significantly higher and serum folate levels significantly lower in the patients than in the controls (P < .0001). These data suggest that MTHFR gene polymorphisms may be involved in the pathogenesis of SHL. PMID:16275406

Capaccio, Pasquale; Ottaviani, Francesco; Cuccarini, Valeria; Ambrosetti, Umberto; Fagnani, Enrico; Bottero, Alessandro; Cenzuales, Salvatore; Cesana, Bruno Mario; Pignataro, Lorenzo

2005-01-01

103

MTHFR C677T genotype as a risk factor for epilepsy including post-traumatic epilepsy in a representative military cohort.  

PubMed

The well-studied C677T variant in the methylenetetrahydrofolate reductase (MTHFR) enzyme is a biologically plausible genetic risk factor for seizures or epilepsy. First, plasma/serum levels of homocysteine, a pro-convulsant, are moderately elevated in individuals with the homozygote TT genotype. Furthermore, the TT genotype has been previously linked with migraine with aura-a comorbid condition-and with alcohol withdrawal seizures. Finally, several small studies have suggested that the TT genotype may be overrepresented in epilepsy patients. In this study, we consider whether the MTHFR C677T or A1298C variants are associated with risk of epilepsy including post-traumatic epilepsy (PTE) in a representative military cohort. Study subjects were selected from the cohort of military personnel on active duty during the years 2003 through 2007 who had archived serum samples at the DoD Serum Repository, essentially all active duty personnel during this time frame. We randomly selected 800 epilepsy patients and 800 matched controls based on ICD-9-CM diagnostic codes. We were able to isolate sufficient genetic material from the archived sera to genotype approximately 85% of our study subjects. The odds of epilepsy were increased in subjects with the TT versus CC genotype (crude OR=1.52 [1.04-2.22], p=0.031; adjusted OR=1.57 [1.07-2.32], p=0.023). In our sensitivity analysis, risk was most evident for patients with repeated rather than single medical encounters for epilepsy (crude OR=1.85 [1.14-2.97], p=0.011, adjusted OR=1.95 [1.19-3.19], p=0.008), and particularly for PTE (crude OR=3.14 [1.41-6.99], p=0.005; adjusted OR=2.55 [1.12-5.80], p=0.026). Our early results suggest a role for the common MTHFR C677T variant as a predisposing factors for epilepsy including PTE. Further exploration of baseline homocysteine and folate levels as predictors of seizure risk following traumatic brain injury is warranted. PMID:21787169

Scher, Ann I; Wu, Holly; Tsao, Jack W; Blom, Henk J; Feit, Preethy; Nevin, Remington L; Schwab, Karen A

2011-09-01

104

Influence of Methylenetetrahydrofolate Reductase C677T Polymorphism on the Risk of Lung Cancer and the Clinical Response to Platinum-Based Chemotherapy for Advanced Non-Small Cell Lung Cancer: An Updated Meta-Analysis  

PubMed Central

Purpose Methylenetetrahydrofolate reductase (MTHFR) has been implicated in lung cancer risk and response to platinum-based chemotherapy in advanced non-small cell lung cancer (NSCLC). However, the results are controversial. We performed meta-analysis to investigate the effect of MTHFR C677T polymorphism on lung cancer risk and response to platinum-based chemotherapy in advanced NSCLC. Materials and Methods The databases of PubMed, Ovid, Wanfang and Chinese Biomedicine were searched for eligible studies. Nineteen studies on MTHFR C677T polymorphism and lung cancer risk and three articles on C677T polymorphism and response to platinum-based chemotherapy in advanced NSCLC, were identified. Results The results indicated that the allelic contrast, homozygous contrast and recessive model of the MTHFR C677T polymorphism were associated significantly with increased lung cancer risk. In the subgroup analysis, the C677T polymorphism was significantly correlated with an increased risk of NSCLC, with the exception of the recessive model. The dominant model and the variant T allele showed a significant association with lung cancer susceptibility of ever smokers. Male TT homozygote carriers had a higher susceptibility, but the allelic contrast and homozygote model had a protective effect in females. No relationship was observed for SCLC in any comparison model. In addition, MTHFR 677TT homozygote carriers had a better response to platinum-based chemotherapy in advanced NSCLC in the recessive model. Conclusion The MTHFR C677T polymorphism might be a genetic marker for lung cancer risk or response to platinum-based chemotherapy in advanced NSCLC. However, our results require further verification. PMID:24142642

Zhu, Ning; Gong, Yi; He, Jian; Xia, Jingwen

2013-01-01

105

Prevalence of genetic mutations that predispose to thrombophilia in a Greek Cypriot population.  

PubMed

Several hereditary disorders, particularly those affecting the physiological anticoagulation systems, have been well established as risk factors for venous thromboembolism. In the present study, we investigated the prevalence of the following thrombogenic mutations in a Greek-Cypriot population: the G1691 factor V Leiden mutation, the G20210A mutation in the prothrombin gene, and the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR). All three variants have been documented to be significant risk factors for various cardiovascular conditions. Ninety unrelated subjects were screened. For the Leiden mutation, 11 subjects (12.2%) were heterozygous and one (1.1%) was homozygous. Seven subjects (7.8%) were heterozygous for the G20210A variant in prothrombin; no homozygotes were identified. The C677T mutation in MTHFR was found in 40 individuals in the heterozygous state (44.4%), and in 16 individuals in the homozygous state (17.8%). These data demonstrate that Greek-Cypriots have an increased frequency of thrombogenic mutations, and suggest that screening for these mutations should be seriously considered, especially when surgery or pregnancy is planned. This is the first study for the frequency of mutations in risk factors that predispose to thrombophilia on the island of Cyprus. PMID:10775032

Angelopoulou, K; Nicolaides, A; Constantinou Deltas, C

2000-04-01

106

Methylenetetrahydrofolate reductase gene polymorphisms in 13 Chinese ethnic populations.  

PubMed

It has been shown that the polymorphisms of Methylenetetrahydrofolate reductase (MTHFR) gene are associated with susceptibility to several disorders including hyperhomocysteinemia, vascular disease, birth defect, and certain cancers, and exhibit great diversities among various populations. The aim of this study was to investigate the prevalence of two common non-synonymous single nucleotide polymorphisms (i.e., C677T and A1298C) at MTHFR gene in 13 Chinese populations. A total of 1015 healthy individuals from 13 populations distributed widely from north to south in China were studied. DNA samples were isolated from peripheral blood samples and genotyped using polymerase chain reaction-restriction fragment length polymorphism. For C677T polymorphism, the frequency in Chinese of CC homozygous was 42.4%; CT heterozygous was 49.8%; and TT homozygous was 7.9%. For A1298C, AA homozygous was 39.2%; AC heterozygous was 38.6%; and CC homozygous was 22.2%. The allelic frequency of 677T and 1298C was 32.8 and 41.5%, respectively, and each allele frequency had significant variance in 13 Chinese populations. The frequency of the 677T allele among southern populations was 30.7% compared to 38.0% among northeastern and 30.5% among northwestern populations. The difference was statistically significant (p < 0.01). The frequency of 1298C mutation in southerns was 58.9% whereas in northeasterns it was 24.0% and 37.6% in northwesterns. This was also statistically significant (p < 0.01). The MTHFR C677T and A1298C sites were in linkage disequilibrium in the Chinese population revealed by our data. PMID:18098118

Mao, Renfang; Fan, Yihui; Chen, Feng; Sun, Donglin; Bai, Jing; Fu, Songbin

2008-04-01

107

Evaluation of Factor V G1691A, prothrombin G20210A, Factor XIII V34L, MTHFR A1298C, MTHFR C677T and PAI-1 4G/5G genotype frequencies of patients subjected to cardiovascular disease (CVD) panel in south-east region of Turkey.  

PubMed

Cardiovascular disease (CVD) risk factors, such as arterial hypertension, obesity, dyslipidemia or diabetes mellitus, as well as CVDs, including myocardial infarction, coronary artery disease or stroke, are the most prevalent diseases and account for the major causes of death worldwide. In the present study, 4,709 unrelated patients subjected to CVD panel in south-east part of Turkey between the years 2010 and 2013 were enrolled and DNA was isolated from the blood samples of these patients. Mutation analyses were conducted using the real-time polymerase chain reaction method to screen six common mutations (Factor V G1691A, PT G20210A, Factor XIII V34L, MTHFR A1298C and C677T and PAI-1 -675 4G/5G) found in CVD panel. The prevalence of these mutations were 0.57, 0.25, 2.61, 13.78, 9.34 and 24.27 % in homozygous form, respectively. Similarly, the mutation percent of them in heterozygous form were 7.43, 3.44, 24.91, 44.94, 41.09 and 45.66%, respectively. No mutation was detected in 92 (1.95%) patients in total. Because of the fact that this is the first study to screen six common mutations in CVD panel in south-east region of Turkey, it has a considerable value on the diagnosis and treatment of these diseases. Upon the results of the present and previous studied a careful examination for these genetic variants should be carried out in thrombophilia screening programs, particularly in Turkish population. PMID:24532105

Oztuzcu, Serdar; Ergun, Sercan; Ula?l?, Mustafa; Nacarkahya, Gülper; I?ci, Yusuf Ziya; I?ci, Mehri; Bayraktar, Recep; Tamer, Ali; Çakmak, Ecir Ali; Arslan, Ahmet

2014-06-01

108

Deep vein thrombosis after bunionectomy: a case report of two genetic mutations.  

PubMed

Deep venous thrombosis after foot and ankle surgery is a serious complication that can have potentially life-threatening complications, such as pulmonary embolus. Genetic mutations have been reported in the published data to cause an increased risk of developing deep vein thrombosis. Two such genetic mutations are the methylenetetrahydrofolate reductase gene variant C677T and the 4G/5G polymorphism of the plasminogen activator inhibitor gene. This case report presents a female patient who developed a postoperative deep vein thrombosis after hallux valgus reconstruction. A hypercoagulable panel revealed the 2 mentioned genetic mutations. We hope this case study will highlight the importance of ascertaining all patient risk factors and the relation to perioperative deep vein thrombosis prophylaxis. PMID:21741861

Peterson, Kyle S; Mendicino, Robert W; Catanzariti, Alan R; Saltrick, Karl R

2011-01-01

109

A Lower Degree of PBMC L1 Methylation in Women with Lower Folate Status May Explain the MTHFR C677T Polymorphism Associated Higher Risk of CIN in the US Post Folic Acid Fortification Era  

PubMed Central

Background Studies in populations unexposed to folic acid (FA) fortification have demonstrated that MTHFR C677T polymorphism is associated with increased risk of higher grades of cervical intraepithelial neoplasia (CIN 2+). However, it is unknown whether exposure to higher folate as a result of the FA fortification program has altered the association between MTHFR C677T and risk of CIN, or the mechanisms involved with such alterations. The current study investigated the following in a FA fortified population: 1) The association between MTHFR C677T polymorphism and risk of CIN 2+; 2) The modifying effects of plasma folate concentrations on this association; and 3) The modifying effects of plasma folate on the association between the polymorphism and degree of methylation of long interspersed nucleotide elements (L1s), in peripheral blood mononuclear cell (PBMC) DNA, a documented biomarker of CIN risk. Methods The study included 457 US women diagnosed with either CIN 2+ (cases) or ? CIN 1 (non-cases). Unconditional logistic regression models were used to test the associations after adjusting for relevant risk factors for CIN. Results The 677CT/TT MTHFR genotypes were not associated with the risk of CIN 2+. Women with CT/TT genotype with lower folate, however, were more likely to be diagnosed with CIN 2+ compared to women with CT/TT genotype with higher folate (OR?=?2.41, P?=?0.030). Women with CT/TT genotype with lower folate were less likely to have a higher degree of PBMC L1 methylation compared to women with CT/TT genotype with higher folate (OR?=?0.28, P?=?0.017). Conclusions This study provides the first evidence that the MTHFR 677CT/TT genotype-associated lower degree of PBMC L1 methylation increases the risk of CIN 2+ in women in the US post-FA fortification era. Thus, even in the post-FA fortification era, not all women have adequate folate status to overcome MTHFR 677CT/TT genotype-associated lower degree of L1 methylation. PMID:25302494

Badiga, Suguna; Johanning, Gary L.; Macaluso, Maurizio; Azuero, Andres; Chambers, Michelle M.; Siddiqui, Nuzhat R.; Piyathilake, Chandrika J.

2014-01-01

110

Congenital IL-12R1? receptor deficiency and thrombophilia in a girl homozygous for an IL12RB1 mutation and compound heterozygous for MTFHR mutations: A case report and literature review.  

PubMed

Interleukin-12 (IL-12) plays an important role in the production of interferon gamma from T cells and natural killer cells and is essential for protection against intra-macrophagic pathogens such as Mycobacterium and Salmonella. Here, we describe a 16-year-old girl with homozygous mutation in exon 12 of the IL12RB1 gene, which causes complete IL-12R?1 deficiency in association with heterozygous mutation (C677T and A1298C) in the methylenetetrahydrofolate reductase gene. She presented with disseminated Mycobacterium tuberculosis complex infection, retroperitoneal fungal abscess and also thrombosis in the superior mesenteric-portal vein junction. This is the first case report of a primary immunodeficiency associated with a genetically determined venous thrombosis. PMID:24678409

Akar, H H; Kose, M; Ceylan, O; Patiroglu, T; Bustamante, J; Casanova, J L; Akyildiz, B N; Doganay, S

2014-03-01

111

Congenital IL-12R1? receptor deficiency and thrombophilia in a girl homozygous for an IL12RB1 mutation and compound heterozygous for MTFHR mutations: A case report and literature review  

PubMed Central

Interleukin-12 (IL-12) plays an important role in the production of interferon gamma from T cells and natural killer cells and is essential for protection against intra-macrophagic pathogens such as Mycobacterium and Salmonella. Here, we describe a 16-year-old girl with homozygous mutation in exon 12 of the IL12RB1 gene, which causes complete IL-12R?1 deficiency in association with heterozygous mutation (C677T and A1298C) in the methylenetetrahydrofolate reductase gene. She presented with disseminated Mycobacterium tuberculosis complex infection, retroperitoneal fungal abscess and also thrombosis in the superior mesenteric–portal vein junction. This is the first case report of a primary immunodeficiency associated with a genetically determined venous thrombosis. PMID:24678409

Kose, M.; Ceylan, O.; Patiroglu, T.; Bustamante, J.; Casanova, J. L.; Akyildiz, B. N.; Doganay, S.

2014-01-01

112

Thrombophilic gene polymorphism studies in G6PD deficient individuals from Saudi population.  

PubMed

We performed a study to evaluate the role of three single nucleotide polymorphisms (SNPs), factor V Leiden G1691A (FVL), prothrombin gene mutation G20210A (PRT or FII-G20210A) and methylenotetrahydrofolate reductase variant C677T (MTHFRC677T), as risk factors for G6PD in Saudi populations. Our results did not show any association with the three Thrombophilic genes with FVL gene, no statistical analysis have shown any association with either allele or genotype frequencies OR=0.566, p=.0.667, (95% CI=0.014-22.48) and OR=0.569, p=0.251¸ (95% CI=0.014-22.96).In PRT gene G20210A for G Vs A, p=0.774; OR=0.566 (95%CI; 0.011-29.6); AA+GA Vs GG; p=0.502; OR=0.569 (95%CI=0.010-2969). G and A allele frequencies were similar between cases and controls with no statistical significance. In the MTHFR gene none of the genotypes or allele frequency cannot show any association OR=1.281, p=.0.667, (95% CI=0.414-3.958) and OR=1.1.172, p=0.800¸ (95% CI=0.343-4.008). Similarly, the difference of T allele frequencies between patients and controls was not found any association. In conclusion, our finding indicates that the prevalence of G1691A, G20210A and C677T mutations in G6PD deficient individuals is not statistically different compared to normal subjects and G6PD is not associated with these thrombophilic mutations in Saudi population. PMID:23275730

Alharbi, Khalid K; Khan, Imran Ali; Syed, Rabbani

2012-01-01

113

Correlation of Homocysteine Metabolic Enzymes Gene Polymorphism and Mild Cognitive Impairment in the Xinjiang Uygur Population  

PubMed Central

Background The aim of this study was to investigate the genetic polymorphisms in the homocysteine (HCY) metabolic enzymes in the Xinjiang Uygur population who have mild cognitive impairment (MCI). Material/Methods Based on the epidemiological investigation, 129 cases of diagnosed Uygur MCI patients and a matched control group with 131 cases were enrolled for analyzing the association between the polymorphisms in the HCY metabolism related genes (C677T, A1298C, and G1968A polymorphisms in MTHFR, as well as the A2756G polymorphism in MS) and MCI by using the SNaPshot method. We then determined the homocysteine level in patients. Results In Xinjiang Uygur subjects, the A1298C polymorphisms in MTHFR and the A2756G polymorphisms in the MS gene in the MCI group were different from those in the control group. However, the C677T and G1968A polymorphisms in the MTHFR gene in MCI patients were not different from those in the control group. Multivariate logistic regression showed that, in addition to the well-known risk factors, such as low education level, high cholesterol level, high level of low-density lipoprotein, and high homocysteine levels, the A>G mutation in the MS gene at the rs1805087 locus was another independent risk factor for MCI in the Uyghur MCI population. The risk of MCI in G allele carriers was 2.265 times higher than that in matched control individuals (95% CI: 1.205~4.256, P<0.05). Conclusions The genetic polymorphism of HCY metabolizing enzymes is correlated to the occurrence of MCI in the Xinjiang Uygur population. The A2756G polymorphism in the MS gene could be an independent risk factor for MCI in the Xinjiang Uygur population. PMID:25625218

Luo, Mei; Ji, Huihui; Zhou, Xiaohui; Liang, Jie; Zou, Ting

2015-01-01

114

Association of deep venous thrombosis with prothrombotic gene polymorphism identified in lung cancer cases.  

PubMed

Venous thrombosis is a significant cause of morbidity and mortality in patients with malignancies. We aimed to investigate the association between prothrombotic gene polymorphisms detected in lung cancer cases and deep venous thrombosis (DVT). Totally 66 patients with an established diagnosis of lung cancer, of which 33 developed DVT, were enrolled. Multiplex PCR technique and reverse hybridization strip assay were performed on DNA extracted from peripheral blood, in order to analyze prothrombin G20210A, factor V G1691A, methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, angiotensin converting enzyme (ACE), plasminogen activator inhibitor-1 (PAI-1), and glycoprotein IIIa (Gp IIIa) gene mutations. Among prothrombotic gene polymorphisms investigated in this study, the commonest ones were PAI-1 4G/5G (56% heterozygous, 39% homozygous) and ACE gene mutations (58% heterozygous, 17% homozygous). The presence of homozygous MTHFR A1298C mutation was significantly associated with DVT (P=0.020). Comparing the lung cancer patients with and without DVT, only MTHFR A1298C gene polymorphism differed significantly (P=0.040). We determined a higher rate of prothrombotic gene mutations in lung cancer patients who developed DVT. However, statistical significance was achieved only for MTHFR A1298C gene mutation. Therefore, nongenetic factors for disturbance of hemostatic metabolism should also be considered in lung cancer patients. PMID:21080081

Arslan, Sulhattin; Manduz, Sinasi; Epöztürk, Kür?at; Karahan, O?uz; Akkurt, Ibrahim

2011-04-01

115

Prevalence of thrombophilic mutations in patients with unprovoked thromboembolic disease. A comparative analysis regarding arterial and venous disease  

PubMed Central

Background: Thromboembolic disease (TED) represents one of the main reasons of morbitity and mortality in Western World. Venous and arterial thrombotic disorders have long been viewed as separate pathophysiological entities. However, in recent times the separate nature of arterial and venous thrombotic events has been challenged. Although inherited thrombophilia’s predominant clinical manifestation is venous thrombosis, its contribution to arterial thrombosis remains controversial. Purpose  of  the  study  was  to  evaluate  the  prevalence  of  the  most common  thrombophilic  mutations, FV Leiden G1691A-FVL and FII G20210A-PTM and to assess  the  differences between venous, arterial and mixed thrombotic events. Testing  for polymorphism MTHFR C677T and  antithrombin,  protein  C  and  protein  S was also performed. Correlations with  dyslipidemia, smoking, obesity, homocysteine and antiphospholipid antibodies were made. Methods: 515 patients with unprovoked TED, 263 males, median age 44 years, were studied. Patients were divided into three groups: 258 with venous thrombosis (group A), 239 with arterial (group B) and 18 with mixed episodes (group C). All patients were interviewed regarding family history of TED, origin, smoking and dyslipidemia. Body mass index (BMI) had been calculated. Molecular assessment of the FVL, PTM and MTHFR C677T was performed. Antithrombin, protein C, protein S, APCR, homocysteine, antiphospholipid antibodies and lipid profile were also measured. Results: The population studied was homogenous among three groups as regards age (p=0.943), lipid profile (p=0.271), BMI (p=0.506), homocysteine (p=0.177), antiphospholipid antibodies (p=0.576), and positive family history (p=0.099). There was no difference in the prevalence of FVL between venous and arterial disease (p=0.440). Significant correlation of PTM with venous TED was found (p=0.001). The number of positive and negative for MTHFR presented statistically significant difference with a support in arterial disease (p=0.05). Moreover, a 2-fold increase in the risk of venous thrombosis in FVL positive patients (odds ratio: 2.153) and a positive correlation of homocysteine levels with MTHFR C677T (p<0.001) was found. Conclusions: Correlation of PTM with venous thrombosis was established. Analysis showed no difference in prevalence of FVL between venous and arterial thrombosis, indicating that FVL might be a predisposing factor for arterial disease. A significant increase in MTHFR C677T prevalence in arterial disease was found. In conclusion, young patients with unprovoked arterial disease should undergo evaluation for thrombophilic genes. Identification of these mutations is important in the overall assessment and management of patients at high risk. Findings will influence the decisions of stratified approaches for antithrombotic therapy either primary or secondary thromboprophylaxis, the duration of therapy, the potential for avoiding clinical thrombosis by risk factor modification and the genetic counselling of family members. However, further studies are needed to clarify the nature of the association regarding venous and arterial thrombotic events. PMID:23935293

Mandala, E; Lafaras, C; Tsioni, C; Speletas, M; Papageorgiou, A; Kleta, D; Dardavessis, T; Ilonidis, G

2012-01-01

116

Two cousins with neonatal stroke, PAI-1 4G variant and MTHFR A1298C mutation.  

PubMed

The authors describe 2 female cousins with neonatal stroke. One was heterozygous for the plasminogen activator inhibitor-1 4G variant and compound heterozygous for the A1298C and C677T methylenetetrahydrofolate reductase mutations. Her cousin was homozygous for the plasminogen activator inhibitor-1 4G variant and heterozygous for the methylenetetrahydrofolate reductase A1298C and factor V Leiden mutations. PMID:17641264

Golomb, Meredith R; Heiny, Mark; Garg, Bhuwan P

2007-06-01

117

The Human Gene Mutation Database: 2008 update  

Microsoft Academic Search

The Human Gene Mutation Database (HGMD®) is a comprehensive core collection of germline mutations in nuclear genes that underlie or are associated with human inherited\\u000a disease. Here, we summarize the history of the database and its current resources. By December 2008, the database contained\\u000a over 85,000 different lesions detected in 3,253 different genes, with new entries currently accumulating at a

Peter D Stenson; Matthew Mort; Edward V Ball; Katy Howells; Andrew D Phillips; Nick ST Thomas; David N Cooper

2009-01-01

118

Epilepsy and fragile X gene mutations  

Microsoft Academic Search

We used two strategies to investigate a possible link between predisposition for epilepsy and mutations in the fragile X mental retardation-1 gene. The first entailed performing electroencephalography on 14 patients with an amplification in the fragile X mental retardation-1 gene, and the second involved molecular genetic analysis of the fragile X mental retardation-1 gene in 16 children with benign childhood

Gerhard Kluger; Ingolf Böhm; Michael C. Laub; Claus Waldenmaier

1996-01-01

119

Methylene tetrahydrofolate reductase (MTHFR) gene polymorphisms in chronic myeloid leukemia: an Egyptian study.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) gene plays a pivotal role in folate metabolism. Several genetic variations in MTHFR gene as MTHFR-C677T and MTHFR-A1298C result in decreased MTHFR activity, which could influence efficient DNA methylation and explain susceptibility to different cancers. The etiology of chronic myeloid leukemia (CML) is obscure and little is known about individual's susceptibility to CML. In order to assess the influence of these genetic polymorphisms on the susceptibility to CML and its effect on the course of the disease among Egyptians, we performed an age-gender-ethnic matched case-control study. The study included 97 CML patients and 130 healthy controls. Genotyping of MTHFR-C677T and -A1298C was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The results showed no statistical difference in the distribution of MTHFR-C677T and -A1298C polymorphic genotypes between CML patients and controls. The frequency of MTHFR 677-TT homozygous variant was significantly higher in patients with accelerated/blastic transformation phase when compared to those in the chronic phase of the disease. In conclusion, our study revealed that MTHFR-C677T and -A1298C polymorphisms could not be considered as genetic risk factors for CML in Egyptians. However, MTHFR 677-TT homozygous variant might be considered as a molecular predictor for disease progression. PMID:24338216

Khorshied, Mervat Mamdooh; Shaheen, Iman Abdel Mohsen; Abu Khalil, Reham E; Sheir, Rania Elsayed

2014-01-01

120

Multipyrene Tandem Probes for Point Mutations Detection in DNA  

PubMed Central

Here we report design, synthesis and characterization of highly sensitive, specific and stable in biological systems fluorescent probes for point mutation detection in DNA. The tandems of 3?- and 5?-mono- and bis-pyrene conjugated oligo(2?-O-methylribonucleotides), protected by 3?-“inverted” thymidine, were constructed and their potential as new instruments for genetic diagnostics was studied. Novel probes have been shown to exhibit an ability to form stable duplexes with DNA target due to the stabilizing effect of multiple pyrene units at the junction. The relationship between fluorescent properties of developed probes, the number of pyrene residues at the tandem junction, and the location of point mutation has been studied. On the basis of the data obtained, we have chosen the probes possessing the highest fluorescence intensity along with the best mismatch discrimination and deletion and insertion detection ability. Application of developed probes for detection of polymorphism C677T in MTHFR gene has been demonstrated on model systems. PMID:24455205

Kholodar, Svetlana A.; Novopashina, Darya S.; Meschaninova, Mariya I.; Venyaminova, Alya G.

2013-01-01

121

Genes and Mutations in Hearing Impairment  

Microsoft Academic Search

The programmed expression of proteins is required for hearing. This chapter describes the structure of chromosomes and genes and delineates how the processes of DNA transcription and RNA translation are required to form functional proteins. In cases of genetic hearing loss, mutations have occurred in either transcription or translation of the genes that encode for proteins crucial for the proper

Karen B. Avraham; Tama Hasson

122

Novel mutations in the human HPRT gene.  

PubMed

Inherited mutation of a purine salvage enzyme, hypoxanthine guanine phosphoribosyltransferase (HPRT), gives rise to Lesch-Nyhan Syndrome (LNS) or HPRT-related gout. Here, we report five novel independent mutations in the coding region of the HPRT gene from five unrelated male patients manifesting different clinical phenotypes associated with LNS: exon 2: c.133A > G, p.45R > G; c.35A > C, p.12D > A; c.88delG; exon 7: c.530A > T, p.177D > V; and c.318 + 1G > C: IVS3 + 1G > C splice site mutation. PMID:21780909

Nguyen, Khue Vu; Naviaux, Robert K; Paik, Kacie K; Nyhan, William L

2011-06-01

123

[Gene mutations in familial amyotrophic lateral sclerosis].  

PubMed

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive muscle weakness that reflects degeneration of motor neurons in the primary motor cortex, corticospinal tracts, brainstem, and spinal cord. Most ALS cases are sporadic, but about 5%-10% are familial. The majority of familial ALS (FALS) cases follow an autosomal dominant inheritance pattern, and include the following mutations: ALS1, Cu/Zn superoxide dismutase (SOD1); ALS3; ALS4, senataxin; ALS6, fused in sarcoma (FUS); ALS7; ALS8, vesicle-associated membrane protein; ALS9, angiogenin; ALS10, TAR DNA-binding protein (TARDBP); and ALS11/FIG4. Some of these gene mutations are rarely seen in sporadic ALS cases. ALS2/alsin and ALS5 show an autosomal recessive inheritance pattern. Recently, mutations in the gene encoding optineurin, earlier reported to be a causative gene for primary open-angle glaucoma, have also been found in patients with ALS. It has also been demonstrated that a mutation in the D-amino acid oxidase gene is associated with classic adult-onset FALS. However, these genetic defects occur in only about 20%-30% FLAS cases, while most genes causing FALS remain unknown. PMID:21301041

Oda, Masaya; Izumi, Yuishin; Kaji, Ryuji

2011-02-01

124

CARD15 gene mutations in sarcoidosis.  

PubMed

Sarcoidosis, Blau syndrome and Crohn's disease are complex disorders, characterised by granulomatous inflammation affecting a variety of organs. Mutations of the CARD15 gene, on chromosome 16, have been shown to contribute significantly to Crohn's disease and to cause Blau syndrome. These factors prompted the current authors to study CARD15 mutations in sarcoidosis. A total of 138 families were genotyped, including 302 patients with sarcoidosis and 127 patients without a family history of sarcoidosis (together with their parents), for four main coding CARD15 polymorphisms associated with increased risk of Crohn's disease. Furthermore, the gene segment that harbours Blau syndrome mutations was sequenced in 39 selected patients from 39 families with affected siblings identical for one or two parental chromosomes 16s and in eight patients from multi-case families. None of the reported Blau syndrome mutations and no new sequence alterations were found. There was an increased frequency of transmission of the rare allele of the polymorphic sites 802C>T (SNP5) and 2722G>C (SNP12) in at least one of the two study groups. In conclusion, CARD15 mutations, which are important in Crohn's disease and Blau syndrome, play no major role in sarcoidosis in this study population. However, these mutations could be of limited importance, especially in patients without a family history of sarcoidosis. PMID:14621080

Schürmann, M; Valentonyte, R; Hampe, J; Müller-Quernheim, J; Schwinger, E; Schreiber, S

2003-11-01

125

Mutations of the GREAT gene cause cryptorchidism.  

PubMed

In humans, failure of testicular descent (cryptorchidism) is one of the most frequent congenital malformations, affecting 1-3% of newborn boys. The clinical consequences of this abnormality are infertility in adulthood and a significantly increased risk of testicular malignancy. Recently, we described a mouse transgene insertional mutation, crsp, causing high intraabdominal cryptorchidism in homozygous males. A candidate gene Great (G-protein-coupled receptor affecting testis descent), was identified within the transgene integration site. Great encodes a seven-transmembrane receptor with a close similarity to the glycoprotein hormone receptors. The Great gene is highly expressed in the gubernaculum, the ligament that controls testicular movement during development, and therefore may be responsible for mediating hormonal signals that affect testicular descent. Here we show that genetic targeting of the Great gene in mice causes infertile bilateral intraabdominal cryptorchidism. The mutant gubernaculae fail to differentiate, indicating that the Great gene controls their development. Mutation screening of the human GREAT gene was performed using DHPLC analysis of the genomic DNA from 60 cryptorchid patients. Nucleotide variations in GREAT cDNA were found in both the patient and the control populations. A unique missense mutation (T222P) in the ectodomain of the GREAT receptor was identified in one of the patients. This mutant receptor fails to respond to ligand stimulation, implicating the GREAT gene in the etiology in some cases of cryptorchidism in humans. PMID:12217959

Gorlov, Ivan P; Kamat, Aparna; Bogatcheva, Natalia V; Jones, Eric; Lamb, Dolores J; Truong, Anne; Bishop, Colin E; McElreavey, Ken; Agoulnik, Alexander I

2002-09-15

126

Cerebral sinovenous thrombosis associated with MTHFR A1298C mutation in the newborn: a case report.  

PubMed

Although cerebral sinovenous thrombosis (CSVT) is a rare condition in the neonatal period, high rates of morbidity and mortality necessitate the establishment of an early diagnosis. Methylenetetrahydrofolate reductase (MTHFR) plays a central role in the folate cycle and mutations of MTHFR are associated with vascular disease. While the C677T common missense mutation is the most well-defined MTHFR polymorphism, another common missense mutation, A1298C also exists. There has been no reported case of CSVT associated with MTHFR A1298C mutation in the neonatal period. Herein, we report a neonate with CSVT who was found to have MTHFR A1298C homozygosity. PMID:22797907

Cizmeci, Mehmet Nevzat; Kanburoglu, Mehmet Kenan; Akelma, Ahmet Zulfikar; Donmez, Ahsen; Sonmez, Fatma Mujgan; Polat, Aziz; Kosehan, Dilek; Tatli, Mustafa Mansur

2013-02-01

127

?-Globin gene mutations in Isfahan Province, Iran.  

PubMed

?-Thalassemia (?-thal) encompasses a spectrum of mutations including deletion and point mutations on the ?-globin chains that is characterized by a reduction or complete absence of ?-globin genes. Most of the ?-thal cases are deletions involving one (?(+)) or both (?(0)) ?-globin genes, although point mutations (?(T)? or ??(T)) are found as well. In this study, 314 individuals with low hematological values, normal Hb A2 who were not affected with ?-thal or iron deficiency, were investigated for the presence of ?-thal mutations. The most common deletion was -?(3.7) (rightward) with a frequency of 70.7%, followed by ?(-5 nt) (-TGAGG) (8.7%), -?(4.2) (leftward) (4.7%), the polyadenylation signal (polyA2) site (AATAAA?>?AATGAA) (4.2%), -(?)(20.5) (3.8%), Hb Constant Spring [Hb CS, ?142, Stop?Gln; HBA2: c.427T?>?C] (2.9%), polyA1 (AATAAA?>?AATAAG) and ?(codon 19) (GCG?>?GC-, ?2) (16%), and -?-(MED) (0.9%). The results of this study may be valuable for designing a plan for carrier screening, premarital genetic counseling, prenatal diagnosis (PND) and reducing excessive health care costs to an affordable level in Isfahan Province, Iran. PMID:24826792

Karamzade, Arezo; Mirzapour, Hadi; Hoseinzade, Majid; Asadi, Sara; Gholamrezapour, Tahere; Tavakoli, Parvaneh; Salehi, Mansoor; Selebi, Mansoor

2014-01-01

128

The Androgen Receptor Gene Mutations Database.  

PubMed Central

The current version of the androgen receptor (AR) gene mutations database is described. The total number of reported mutations has risen from 272 to 309 in the past year. We have expanded the database: (i) by giving each entry an accession number; (ii) by adding information on the length of polymorphic polyglutamine (polyGln) and polyglycine (polyGly) tracts in exon 1; (iii) by adding information on large gene deletions; (iv) by providing a direct link with a completely searchable database (courtesy EMBL-European Bioinformatics Institute). The addition of the exon 1 polymorphisms is discussed in light of their possible relevance as markers for predisposition to prostate or breast cancer. The database is also available on the internet (http://www.mcgill. ca/androgendb/ ), from EMBL-European Bioinformatics Institute (ftp. ebi.ac.uk/pub/databases/androgen ), or as a Macintosh FilemakerPro or Word file (MC33@musica.mcgill.ca). PMID:9399843

Gottlieb, B; Lehvaslaiho, H; Beitel, L K; Lumbroso, R; Pinsky, L; Trifiro, M

1998-01-01

129

Mutations of the GREAT gene cause cryptorchidism  

Microsoft Academic Search

In humans, failure of testicular descent (cryptorchidism) is one of the most frequent congenital malformations, affecting 1-3% of newborn boys. The clinical consequences of this abnormality are infertility in adulthood and a significantly increased risk of testicular malignancy. Recently, we described a mouse transgene insertional mutation, crsp, causing high intraabdominal cryptorchidism in homozygous males. A candidate gene Great (G-protein-coupled receptor

Ivan P. Gorlov; Aparna Kamat; Natalia V. Bogatcheva; Eric Jones; Dolores J. Lamb; Anne Truong; Colin E. Bishop; Ken McElreavey; Alexander I. Agoulnik

2002-01-01

130

A Recurring FBN1 Gene Mutation in Neonatal Marfan Syndrome  

Microsoft Academic Search

Background: Marfan syndrome is an autosomal domi- nant disorder of connective tissue caused by mutations in the fibrillin 1 gene (FBN1). FBN1 mutations have been associated with a broad spectrum of phenotypes. Neo- natal Marfan syndrome has unique clinical manifesta- tions and mutations. Objective: To determine if there is a discernible geno- typic-phenotypic correlation associated with the unique mutation in

Amanda M. Jacobs; Ivanka Toudjarska; Andrew Racine; Petros Tsipouras; Michael W. Kilpatrick; Alan Shanske

2002-01-01

131

Different Gene Mutations May Determine Severity, Type of Autism  

MedlinePLUS

... features on this page, please enable JavaScript. Different Gene Mutations May Determine Severity, Type of Autism Finding ... 22, 2014 Related MedlinePlus Pages Autism Spectrum Disorder Genes and Gene Therapy MONDAY, Dec. 22, 2014 (HealthDay ...

132

Gene Mutations Linked to Colon Cancer in Black Patients  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Gene Mutations Linked to Colon Cancer in Black Patients ... Related MedlinePlus Pages African American Health Colorectal Cancer Genes and Gene Therapy TUESDAY, Jan. 13, 2015 (HealthDay ...

133

Researchers Find Gene Mutation That May Protect Against Heart Disease  

MedlinePLUS

... on this page, please enable JavaScript. Researchers Find Gene Mutation That May Protect Against Heart Disease Rare ... Preidt Wednesday, November 12, 2014 Related MedlinePlus Pages Genes and Gene Therapy Heart Diseases WEDNESDAY, Nov. 12, ...

134

Childhood Peanut Allergy May Be Linked to Skin Gene Mutation  

MedlinePLUS

... on this page, please enable JavaScript. Childhood Peanut Allergy May Be Linked to Skin Gene Mutation Study ... Friday, October 24, 2014 Related MedlinePlus Pages Food Allergy Genes and Gene Therapy Skin Conditions FRIDAY, Oct. ...

135

NOTCH3 gene mutations in subjects clinically suspected of CADASIL  

Microsoft Academic Search

BackgroundCerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited cerebrovascular disease due to mutations involving loss or gain of a cysteine residue in the NOTCH3 gene. A cluster of mutations around exons 3 and 4 was originally reported. Identification of pathogenic mutation is important for diagnostic confirmation of the disease, however genetic counselling and testing of

Lorena Mosca; Raffaella Marazzi; Alfonso Ciccone; Ignazio Santilli; Anna Bersano; Valeria Sansone; Enrico Grosso; Giorgia Mandrile; Daniela Francesca Giachino; Laura Adobbati; Elisabetta Corengia; Elio Agostoni; Anna Fiumani; Salvatore Gallone; Elio Scarpini; Mario Guidotti; Roberto Sterzi; Clara Ajmone; Alessandro Marocchi; Silvana Penco

2011-01-01

136

Smad2 and Smad4 gene mutations in hepatocellular carcinoma  

Microsoft Academic Search

TGF-? is a negative regulator of liver growth. Smad family of genes, as mediators of TGF-? pathway, are candidate tumor suppressor genes in hepatocellular carcinoma (HCC). We studied 35 HCC and non-tumour liver tissues for possible mutations in Smad2 and Smad4 genes. Three tumours displayed somatic mutations; two in Smad4 (Asp332Gly and Cys401Arg) and one in Smad2 (Gln407Arg) genes. All

M C Yakicier; M B Irmak; A Romano; M Kew; M Ozturk

1999-01-01

137

Mutations and Disease Mutations in the HFE gene are associated with the hemochromatosis  

E-print Network

1 Mutations and Disease Mutations in the HFE gene are associated with the hemochromatosis disease. A laboratory working on the hemochromatosis disease wants to elucidate the biochemical and structural basis and their locations in the HFE gene (using dbSNP). 3. Learn more about hemochromatosis and its genetic testing (using

Levin, Judith G.

138

New ABCC6 gene mutations in German pseudoxanthoma elasticum patients  

Microsoft Academic Search

Pseudoxanthoma elasticum (PXE; OMIM 177850 and 264800) is a rare heritable disorder of the connective tissue affecting the extracellular matrix of the skin, eyes, gastrointestinal system, and cardiovascular system. It has recently been found that mutations in the ABCC6 gene encoding the multidrug resistance-associated protein (MRP) 6 cause PXE. This study examined novel mutations in the ABCC6 gene in our

Doris Hendig; Veronika Schulz; Jutta Eichgrün; Christiane Szliska; Christian Götting; Knut Kleesiek

2005-01-01

139

Mutational analysis of the lambda S gene  

E-print Network

BR322) AmpR lacPO StsgB R+Rz (in pBR322) Amp lacPO Sam7 R+Rz+ (in pBR322) AmpR TetR glori I3 AmpR TetR ~ori 13 AmpR glori 13 lacPO g'R+Rz+ (from pZ150) AmpR ~ori 13 lacPO S+R+Rz+ (from pZ150) lab. stock lab. stock J. Messing (40) (20... should be very low. In fact, only I of the sequenced S 25 TABLE 2. Possible S gene mutations. a aagb aa codon possible codon changes change in aa 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29...

Neal, Gregory Scott

2012-06-07

140

[Role of gene polymorphism in development of thromboses].  

PubMed

The development of thromboses is one of the most common causes of morbidity and mortality in the Western world. The perturbation of haemostasis is the central event in the pathogenesis of all thromboses. Most patients with thromboses have no recognisable associated haemostatic disorders. However, some patients do manifest hereditary hypercoagulable states, which contribute to the development of thromboses as well as other clinical manifestations, such as miscarriages and foetal complications. The major determinants of thrombosis include both environmental influences and genetic factors. Transient or long-lasting environmental influences may play important roles in arterial and venous thromboses. Haemostatic perturbance may also be genetically determined and exert a life-long influence. Specific mutations of genes predisposed to thrombosis, such as deficiency of antithrombin, protein C, or protein S, are found in relatively small number of families. In the absence of genetic deficiencies, thrombosis occurs in the older population, largely within the context of marked environmental influences (such as surgery, obesity, and malignancy). In contrast, familial thrombosis, associated with gene mutation, is associated with a younger age. The general importance of gene polymorphism was established after the recognition of activated protein C resistance (APCR) due to gene polymorphism G1691A in factor V (Factor V Leiden). This single gene defect increases the risk of venous thrombosis, without interaction with other genetic or environmental risk factors. The development of APCR led to many other investigations of gene polymorphism, such as prothrombin 20210, thrombomodulin, factors in the coagulation and fibrinolytic system, glycoproteins of platelet membranes, as well as polymorphism C677T of methylene tetrahydrofolate reductase. The number of potential genetic risk factors for occlusive thrombotic disease has increased significantly. Most of these gene polymorphisms increase the risk of venous thrombosis but there is no strong evidence of their influence as far as arterial thrombosis is concerned. PMID:16796167

Elezovi?, Ivo

2006-05-01

141

21 CFR 866.5900 - Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation detection system.  

Code of Federal Regulations, 2011 CFR

...transmembrane conductance regulator (CFTR) gene mutation detection system. 866.5900...transmembrane conductance regulator (CFTR) gene mutation detection system. (a) Identification . The CFTR gene mutation detection system is a...

2011-04-01

142

21 CFR 866.5900 - Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation detection system.  

...transmembrane conductance regulator (CFTR) gene mutation detection system. 866.5900...transmembrane conductance regulator (CFTR) gene mutation detection system. (a) Identification. The CFTR gene mutation detection system is a...

2014-04-01

143

21 CFR 866.5900 - Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation detection system.  

Code of Federal Regulations, 2013 CFR

...transmembrane conductance regulator (CFTR) gene mutation detection system. 866.5900...transmembrane conductance regulator (CFTR) gene mutation detection system. (a) Identification . The CFTR gene mutation detection system is a...

2013-04-01

144

21 CFR 866.5900 - Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutation detection system.  

Code of Federal Regulations, 2012 CFR

...transmembrane conductance regulator (CFTR) gene mutation detection system. 866.5900...transmembrane conductance regulator (CFTR) gene mutation detection system. (a) Identification . The CFTR gene mutation detection system is a...

2012-04-01

145

Gene Expression in the Star Mutation of Petunia x Hybrida  

Technology Transfer Automated Retrieval System (TEKTRAN)

Differences in structural gene expression are responsible for a wide range of responses from human cancer to patterned flowers. Gene silencing is one of the ways in which gene expression is controlled. We have developed a model system to study anthocyanin gene silencing using a mutation in Petunia ...

146

Clustering of mutations in the carbamyl phosphate synthetase I gene  

SciTech Connect

The carbamyl phosphate synthetase I (CPSI) gene encodes the 165 kDa protein catalyzing the first step of the urea cycle, and its deficiency leads to life-threatening hyperammonemia in the newborn period. In our study of the molecular changes underlying CPSID we have found three silent mutations, two single base deletion mutants, four missense mutations that are present in both controls and patients, and two missense mutations present only in CPSID patients. These mutations are clustered in two exonic regions. Region one is located between the ATP-bicarbonate binding domains near the 3{prime} end of the message and is 220 bases in size (4% of total message). It contains 7 of the 11 mutations. Region two spanning 350 bases (7% of total message) contains the 4 remaining mutations and includes an ATP-bicarbonate binding domain. These mutations do not occur at CpG dinucleotides and sequence analysis revealed no hairpin loops or other structures. While analysis for intrageneic homologies revealed several small direct and inverted repeats involving the mutated sequences, the corresponding regions did not contain sequences consistent with the mutations found. Although the underlying cause of these mutation clusters is unclear, their presence suggests a configuration either in the primary sequence or a secondary/tertiary structure leading to a degradation in sequence fidelity. Additionally, the location of 11 of the 12 mutations in the CPSI gene within 11% of the message length allows us to narrow our initial mutation searches in CPSID patients.

Summar, M.L.; Hall, L. [Vanderbilt Univ. Medical Center, Nashville, TN (United States)

1994-09-01

147

Mutations of the BRAF gene in human cancer  

Microsoft Academic Search

Cancers arise owing to the accumulation of mutations in critical genes that alter normal programmes of cell proliferation, differentiation and death. As the first stage of a systematic genome-wide screen for these genes, we have prioritized for analysis signalling pathways in which at least one gene is mutated in human cancer. The RAS-RAF-MEK-ERK-MAP kinase pathway mediates cellular responses to growth

Helen Davies; Graham R. Bignell; Charles Cox; Philip Stephens; Sarah Edkins; Sheila Clegg; Jon Teague; Hayley Woffendin; Mathew J. Garnett; William Bottomley; Neil Davis; Ed Dicks; Rebecca Ewing; Yvonne Floyd; Kristian Gray; Sarah Hall; Rachel Hawes; Jaime Hughes; Vivian Kosmidou; Andrew Menzies; Catherine Mould; Adrian Parker; Claire Stevens; Stephen Watt; Steven Hooper; Rebecca Wilson; Hiran Jayatilake; Barry A. Gusterson; Colin Cooper; Janet Shipley; Darren Hargrave; Katherine Pritchard-Jones; Norman Maitland; Georgia Chenevix-Trench; Gregory J. Riggins; Darell D. Bigner; Giuseppe Palmieri; Antonio Cossu; Adrienne Flanagan; Andrew Nicholson; Judy W. C. Ho; Suet Y. Leung; Siu T. Yuen; Barbara L. Weber; Hilliard F. Seigler; Timothy L. Darrow; Hugh Paterson; Richard Marais; Christopher J. Marshall; Richard Wooster; Michael R. Stratton; P. Andrew Futreal

2002-01-01

148

Polymorphisms in genes involved in folate metabolism and colorectal neoplasia: a HuGE review.  

PubMed

Epidemiologic and mechanistic evidence suggests that folate is involved in colorectal neoplasia. Some polymorphic genes involved in folate metabolism--methylenetetrahydrofolate reductase (MTHFR C677T and A1298C), methionine synthase (MTR A2756G), methionine synthase reductase (MTRR A66G), cystathionine beta-synthase (CBS exon 8, 68-base-pair insertion), and thymidylate synthase (TS enhancer region and 3' untranslated region)--have been investigated in colorectal neoplasia. For MTHFR C677T and A1298C, the variant allele is associated with reduced enzyme activity in vitro. For the other polymorphisms, functional data are limited and/or inconsistent. Genotype frequencies for all of the polymorphisms show marked ethnic and geographic variation. In most studies, MTHFR 677TT (10 studies, >4,000 cases) and 1298CC (four studies, >1,500 cases) are associated with moderately reduced colorectal cancer risk. In four of five genotype-diet interaction studies, 677TT subjects who had higher folate levels (or a "high-methyl diet") had the lowest cancer risk. In two studies, 677TT homozygote subjects with the highest alcohol intake had the highest cancer risk. Findings from six studies of MTHFR C677T and adenomatous polyps are inconsistent. There have been only one or two studies of the other polymorphisms; replication is needed. Overall, the roles of folate-pathway genes, folate, and related dietary factors in colorectal neoplasia are complex. Research priorities are suggested. PMID:14977639

Sharp, Linda; Little, Julian

2004-03-01

149

CFTR gene mutations in isolated chronic obstructive pulmonary disease  

SciTech Connect

In order to identify a possible hereditary predisposition to the development of chronic obstructive pulmonary disease (COPD), we have looked for the presence of cystic fibrosis transmembrane regulator (CFTR) gene DNA sequence modifications in 28 unrelated patients with no signs of cystic fibrosis. The known mutations in Italian CF patients, as well as the most frequent worldwide CF mutations, were investigated. In addition, a denaturing gradient gel electrophoresis analysis of about half of the coding sequence of the gene in 56 chromosomes from the patients and in 102 chromosomes from control individuals affected by other pulmonary diseases and from normal controls was performed. Nine different CFTR gene mutations and polymorphisms were found in seven patients, a highly significant increase over controls. Two of the patients were compound heterozygotes. Two frequent CF mutations were detected: deletion F508 and R117H; two rare CF mutations: R1066C and 3667ins4; and five CF sequence variants: R75Q (which was also described as a disease-causing mutation in male sterility cases due to the absence of the vasa deferentia), G576A, 2736 A{r_arrow}G, L997F, and 3271+18C{r_arrow}T. Seven (78%) of the mutations are localized in transmembrane domains. Six (86%) of the patients with defined mutations and polymorphisms had bronchiectasis. These results indicate that CFTR gene mutations and sequence alterations may be involved in the etiopathogenesis of some cases of COPD.

Pignatti, P.F.; Bombien, C.; Marigo, C. [and others

1994-09-01

150

KMD: Korean Mutation Database for genes related to diseases.  

PubMed

The number of known disease-causing mutations has increased dramatically. However, there have been few organized mutation databases developed that are available to the public or not-for-profit entities. Thus, clinicians and diagnostic laboratories had to spend time searching many publications and databases to determine whether a mutation has been previously reported. To assist in genetic diagnoses, the systematic collection and curation of mutations are necessary. The Korean Mutation Database (KMD; http://kmd.cdc.go.kr) is a country-specific database of human gene mutations that was established in September 2009. The KMD is a database consolidating mutations of genes related to diseases in Korea; it now contains more than 1,600 mutations from 245 genes. We collected mutation data from diagnostic laboratories and published journals over recent decades in Korea. KMD has been open to the public for searches and registration of mutation data without charge. Our aim is to provide organized information for clinicians and researchers who are interested in genetic diseases. It will be useful not only for researchers in Korea but also for researchers in countries with similar ethnic backgrounds. Ultimately, KMD will be an essential base to improve researches in genetic diseases, developments of diagnostics, and therapeutic optimization. PMID:22323337

Park, Mi-Hyun; Koo, Soo Kyung; Lee, Jin-Sung; Yoo, Han-Wook; Kim, Jong-Won; Cheong, Hae Il; Park, Hyun-Young

2012-04-01

151

Ferredoxin Gene Mutation in Iranian Trichomonas vaginalis Isolates  

PubMed Central

Background Trichomonas vaginalis causes trichomoniasis and metronidazole is its chosen drug for treatment. Ferredoxin has role in electron transport and carbohydrate metabolism and the conversion of an inactive form of metronidazole (CO) to its active form (CPR). Ferredoxin gene mutations reduce gene expression and increase its resistance to metronidazole. In this study, the frequency of ferredoxin gene mutations in clinical isolates of T.vaginalis in Tehran has been studied. Methods Forty six clinical T. vaginalis isolates of vaginal secretions and urine sediment were collected from Tehran Province since 2011 till 2012. DNA was extracted and ferredoxin gene was amplified by PCR technique. The ferredoxin gene PCR products were sequenced to determine gene mutations. Results In four isolates (8.69%) point mutation at nucleotide position -239 (the translation start codon) of the ferredoxin gene were detected in which adenosine were converted to thymine. Conclusion Mutation at nucleotide -239 ferredoxin gene reduces translational regulatory protein's binding affinity which concludes reduction of ferredoxin expression. For this reduction, decrease in activity and decrease in metronidazole drug delivery into the cells occur. Mutations in these four isolates may lead to resistance of them to metronidazole. PMID:24454433

HEIDARI, Soudabeh; BANDEHPOUR, Mojgan; SEYYED-TABAEI, Seyyed-Javad; VALADKHANI, Zarintaj; HAGHIGHI, Ali; ABADI, AliReza; KAZEMI, Bahram

2013-01-01

152

Androgen receptor gene mutation, rearrangement, polymorphism.  

PubMed

Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10-30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents. PMID:25045626

Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E; Wang, Zhou

2013-09-01

153

Androgen receptor gene mutation, rearrangement, polymorphism  

PubMed Central

Genetic aberrations of the androgen receptor (AR) caused by mutations, rearrangements, and polymorphisms result in a mutant receptor that has varied functions compared to wild type AR. To date, over 1,000 mutations have been reported in the AR with most of these being associated with androgen insensitivity syndrome (AIS). While mutations of AR associated with prostate cancer occur less often in early stage localized disease, mutations in castration-resistant prostate cancer (CRPC) patients treated with anti-androgens occur more frequently with 10–30% of these patients having some form of mutation in the AR. Resistance to anti-androgen therapy usually results from gain-of-function mutations in the LBD such as is seen with bicalutamide and more recently with enzalutamide (MDV3100). Thus, it is crucial to investigate these new AR mutations arising from drug resistance to anti-androgens and other small molecule pharmacological agents. PMID:25045626

Eisermann, Kurtis; Wang, Dan; Jing, Yifeng; Pascal, Laura E.; Wang, Zhou

2014-01-01

154

Aneuploidy versus gene mutation as cause of cancer  

Microsoft Academic Search

The mutagenic ranges of aneuploidy, an abnormal number of chromosomes, and gene mutation are analyzed for their abilities to cause the dominan t phe- notypes of cancer. In the cell, activating gene mut a- tions are buffered because virtually all gene products are kinetically linked into biochemical assembly lines and thus functionally controlled by upstream and downstream enzymes working at

Peter Duesberg; Reinhard Stindl; Ruhong Li; Ruediger Hehlmann; David Rasnick

2001-01-01

155

Preservation of Duplicate Genes by Complementary, Degenerative Mutations  

Microsoft Academic Search

The origin of organismal complexity is generally thought to be tightly coupled to the evolution of new gene functions arising subsequent to gene duplication. Under the classical model for the evolution of duplicate genes, one member of the duplicated pair usually degenerates within a few million years by accumulating deleterious mutations, while the other duplicate retains the original function. This

Allan Force; Michael Lynch; F. Bryan Pickett; Angel Amores; Yi-lin Yan; John Postlethwait

1999-01-01

156

Four novel mutations of the coproporphyrinogen III oxidase gene.  

PubMed

Here we report the characterization of four novel mutations and a previously described one of the coproporphyrinogen III oxidase (CPO) gene in five Italian patients affected by Hereditary Coproporphyria (HCP). Three of the novel genetic variants are missense mutations (p.Gly242Cys; p.Leu398Pro; p.Ser245Phe) and one is a frameshift mutation (p.Gly188TrpfsX45). PMID:19267996

Aurizi, C; Lupia Palmieri, G; Barbieri, L; Macrì, A; Sorge, F; Usai, G; Biolcati, G

2009-01-01

157

Diverse growth hormone receptor gene mutations in Laron syndrome.  

PubMed Central

To better understand the molecular genetic basis and genetic epidemiology of Laron syndrome (growth-hormone insensitivity syndrome), we analyzed the growth-hormone receptor (GHR) genes of seven unrelated affected individuals from the United States, South America, Europe, and Africa. We amplified all nine GHR gene exons and splice junctions from these individuals by PCR and screened the products for mutations by using denaturing gradient gel electrophoresis (DGGE). We identified a single GHR gene fragment with abnormal DGGE results for each affected individual, sequenced this fragment, and, in each case, identified a mutation likely to cause Laron syndrome, including two nonsense mutations (R43X and R217X), two splice-junction mutations, (189-1 G to T and 71 + 1 G to A), and two frameshift mutations (46 del TT and 230 del TA or AT). Only one of these mutations, R43X, has been previously reported. Using haplotype analysis, we determined that this mutation, which involves a CpG dinucleotide hot spot, likely arose as a separate event in this case, relative to the two prior reports of R43X. Aside from R43X, the mutations we identified are unique to patients from particular geographic regions. Ten GHR gene mutations have now been described in this disorder. We conclude that Laron syndrome is caused by diverse GHR gene mutations, including deletions, RNA processing defects, translational stop codons, and missense codons. All the identified mutations involve the extracellular domain of the receptor, and most are unique to particular families or geographic areas. Images Figure 1 Figure 2 PMID:8488849

Berg, M A; Argente, J; Chernausek, S; Gracia, R; Guevara-Aguirre, J; Hopp, M; Pérez-Jurado, L; Rosenbloom, A; Toledo, S P; Francke, U

1993-01-01

158

Diverse growth hormone receptor gene mutations in Laron syndrome  

SciTech Connect

To better understand the molecular genetic basis and genetic epidemiology of Laron syndrome (growth-hormone insensitivity syndrome), the authors analysed the growth-hormone receptor (GHR) genes of seven unrelated affected individuals from the United States, South America, Europe, and Africa. They amplified all nine GHR gene exons and splice junctions from these individuals by PCR and screened the products for mutations by using denaturing gradient gel electrophoresis (DGGE). They identified a single GHR gene fragment with abnormal DGGE results for each affected individual, sequenced this fragment, and, in each case, identified a mutation likely to cause Laron syndrome, including two nonsense mutations (R43X and R217X), two splice-junction mutations, (189-1 G to T and 71+1 G to A), and two frameshift mutations (46 del TT and 230 del TA or AT). Only one of these mutations, R43X, has been previously reported. Using haplotype analysis, they determined that this mutation, which involves a CpG dinucleotide hot spot, likely arose as a separate event in this case, relative to the two prior reports of R43X. Aside from R43X, the mutations identified are unique to patients from particular geographic regions. Ten GHR gene mutations have now been described in this disorder. The authors conclude that Laron syndrome is caused by diverse GHR gene mutations, including deletions, RNA processing defects, translational stop codons, and missense codons. All the identified mutations involve the extracellular domain of the receptor, and most are unique to particular families or geographic areas. 35 refs., 3 figs., 1 tab.

Berg, M.A.; Francke, U. (Stanford Univ. School of Medicine, CA (United States)); Gracia, R.; Rosenbloom, A.; Toledo, S.P.A. (Univ. Autonoma, Madrid (Spain)); Chernausek, S. (Children's Hospital Medical Center, Cincinnati, OH (United States)); Guevara-Aguirre, J. (Institute of Endocrinology, Metabolism, and Reproduction, Quito (Ecuador)); Hopp, M. (Univ. of Witwatersrand, Johannesburg (South Africa)); Rosenbloom, A.; Argente, J. (Univ. of Florida, Gainesville (United States)); Toledo, S.P.A. (Univ. of Sao Paulo (Brazil))

1993-05-01

159

Bioinformatic Analysis of GJB2 Gene Missense Mutations.  

PubMed

Gap junction beta 2 (GJB2) gene is the most commonly mutated connexin gene in patients with autosomal recessive and dominant hearing loss. According to Ensembl (release 74) database, 1347 sequence variations are reported in the GJB2 gene and about 13.5 % of them are categorized as missense SNPs or nonsynonymous variant. Because of the high incidence of GJB2 mutations in hearing loss patients, revealing the molecular effect of GJB2 mutations on protein structure may also provide clear point of view regarding the molecular etiology of deafness. Hence, the aim of this study is to analyze structural and functional consequences of all known GJB2 missense variations to the Cx26 protein by applying multiple bioinformatics methods. Two-hundred and eleven nonsynonymous variants were collected from Ensembl release 74, Leiden Open Variation Database (LOVD) and The Human Gene Mutation Database (HGMD). A number of bioinformatic tools were utilized for predicting the effect of GJB2 missense mutations at the sequence, structural, and functional levels. Some of the mutations were found to locate highly conserved regions and have structural and functional properties. Moreover, GJB2 mutations were also found to affect Cx26 protein at the molecular level via loss or gain of disorder, catalytic site, and post-translational modifications, including methylation, glycosylation, and ubiquitination. Findings, presented here, demonstrated the application of bioinformatic algorithms to predict the effects of mutations causing hearing impairment. I expect, this type of analysis will serve as a start point for future experimental evaluation of the GJB2 gene mutations and it will also be helpful in evaluating other deafness-related gene mutations. PMID:25388846

Yilmaz, Akin

2014-11-12

160

Association between MTHFR gene polymorphisms and the risk of autism spectrum disorders: a meta-analysis.  

PubMed

Methylenetetrahydrofolate reductase (MTHFR) is essential for DNA biosynthesis and the epigenetic process of DNA methylation, and its gene polymorphisms have been implicated as risk factors for birth defects, neurological disorders, and cancers. However, reports on the association of MTHFR polymorphisms with autism spectrum disorders (ASD) are inconclusive. Therefore, we investigated the relationship of the MTHFR polymorphisms (C677T and A1298C) and the risk of ASD by meta-analysis. Up to December 2012, eight case-control studies involving 1672 patients with ASD and 6760 controls were included for meta-analysis. The results showed that the C677T polymorphism was associated with significantly increased ASD risk in all the comparison models [T vs. C allele (frequency of allele): odds ratio (OR)?= 1.42, 95% confidence interval (CI): 1.09-1.85; CT vs. CC (heterozygote): OR = 1.48, 95% CI: 1.09-2.00; TT vs. CC (homozygote): OR = 1.86, 95% CI: 1.08-3.20; CT+TT vs. CC (dominant model): OR = 1.56, 95% CI: 1.12-2.18; and TT vs. CC+CT (recessive model): OR = 1.51, 95% CI: 1.02-2.22], whereas the A1298C polymorphism was found to be significantly associated with reduced ASD risk but only in a recessive model (CC vs. AA+AC: OR = 0.73, 95% CI: 0.56-0.97). In addition, we stratified the patient population based on whether they were from a country with food fortification of folic acid or not. The meta-analysis showed that the C677T polymorphism was found to be associated with ASD only in children from countries without food fortification. Our study indicated that the MTHFR C677T polymorphism contributes to increased ASD risk, and periconceptional folic acid may reduce ASD risk in those with MTHFR 677C>T polymorphism. PMID:23653228

Pu, Danhua; Shen, Yiping; Wu, Jie

2013-10-01

161

Single Cell Analysis of Mutations in the APC Gene  

Microsoft Academic Search

Introduction: Mutation analysis of inherited monogenic diseases is an important aspect of preimplantation genetic diagnosis. Familial adenomatous polyposis of the colon is an autosomal dominant inherited disorder caused by mutations in the tumor suppressor gene adenomatous polyposis coli (APC). A characteristic of this severe disease is the development of thousands of polyps in the colon which untreated evolve into malignant

Veronika Mayer; Ulrike Schoen; Elke Holinski-Feder; Udo Koehler; Stefan Thalhammer

2009-01-01

162

EGF receptor gene mutations are common in lung cancers from  

Microsoft Academic Search

Somatic mutations in the tyrosine kinase (TK) domain of the epidermal growth factor receptor (EGFR) gene are reportedly associated with sensitivity of lung cancers to gefitinib (Iressa), kinase inhibitor. In-frame deletions occur in exon 19, whereas point mutations occur frequently in codon 858 (exon 21). We found from sequencing the EGFR TK domain that 7 of 10 gefitinib-sensitive tumors had

William Pao; Vincent Miller; Maureen Zakowski; Jennifer Doherty; Katerina Politi; Inderpal Sarkaria; Bhuvanesh Singh; Robert Heelan; Valerie Rusch; Lucinda Fulton; Elaine Mardis; Doris Kupfer; Richard Wilson; Mark Kris; Harold Varmus

2004-01-01

163

A mutation spectra database for bacterial and mammalian genes.  

PubMed

Each mutation spectrum in this database is a dataset of changes in DNA base sequence in mutations induced in a gene by a particular mutagen (including spontaneous processes) under defined conditions. There are 240 datasets with 24 500 mutants in nine bacterial genes, two phage genes, five mammalian genes and one yeast gene. The database is available on the Web at http://info.med.yale.edu/mutbase/ . The data tables can be viewed on the Web and downloaded in text form for local use. The data are also available in dBASE III, a format which can be utilized by essentially any desktop computer database program or spreadsheet, and makes feasible analyses of a large number of mutants. Researchers are invited to submit additional data. A data entry program, MUTSIN, diagrams each mutation on the computer screen as the data are entered and alerts the user to any discrepancies between the entry and the gene sequence. PMID:9016534

Hutchinson, F; Donnellan, J E

1997-01-01

164

Influence of Nitrous Oxide Anesthesia, B-Vitamins, and MTHFR gene polymorphisms on Perioperative Cardiac Events: The Vitamins in Nitrous Oxide (VINO) Randomized Trial  

PubMed Central

Background Nitrous oxide causes an acute increase in plasma homocysteine that is more pronounced in patients with the MTHFR C677T or A1298C gene variant. In this randomized controlled trial we sought to determine if patients carrying the MTHFR C677T or A1298C variant had a higher risk for perioperative cardiac events after nitrous oxide anesthesia and if this risk could be mitigated by B-vitamins. Methods We randomized adult patients with cardiac risk factors undergoing noncardiac surgery to receive nitrous oxide plus intravenous B-vitamins before and after surgery or to nitrous oxide and placebo. Serial cardiac biomarkers and 12-lead electrocardiograms were obtained. The primary study endpoint was the incidence of myocardial injury, as defined by cardiac troponin I elevation within the first 72 hours after surgery. Results A total of 500 patients completed the trial. Patients who were homozygous for either MTHFR C677T or A1298C gene variant (n= 98; 19.6%) had no increased rate of postoperative cardiac troponin I elevation compared to wild-type and heterozygous patients (11.2% vs. 14.0%; relative risk 0.96, 95% CI 0.85 to 1.07, p=0.48). B-vitamins blunted the rise in homocysteine, but had no effect on cardiac troponin I elevation compared to patients receiving placebo (13.2% vs. 13.6%; relative risk 1.02, 95% CI 0.78 to 1.32, p=0.91). Conclusions Neither MTHFR C677T and A1298C gene variant nor acute homocysteine increase are associated with perioperative cardiac troponin elevation after nitrousoxide anesthesia. B-vitamins blunt nitrous oxide-induced homocysteine increase but have no effect on cardiac troponin elevation. PMID:23856660

Nagele, Peter; Brown, Frank; Francis, Amber; Scott, Mitchell G.; Gage, Brian F.; Miller, J. Philip

2013-01-01

165

Galactosialidosis: review and analysis of CTSA gene mutations  

PubMed Central

Background Mutations in the CTSA gene, that encodes the protective protein/cathepsin A or PPCA, lead to the secondary deficiency of ?-galactosidase (GLB1) and neuraminidase 1 (NEU1), causing the lysosomal storage disorder galactosialidosis (GS). Few clinical cases of GS have been reported in the literature, the majority of them belonging to the juvenile/adult group of patients. Methods The correct nomenclature of mutations for this gene is discussed through the analysis of the three PPCA/CTSA isoforms available in the GenBank database. Phenotype-genotype correlation has been assessed by computational analysis and review of previously reported single amino acid substitutions. Results We report the clinical and mutational analyses of four cases with the rare infantile form of GS. We identified three novel nucleotide changes, two of them resulting in the missense mutations, c.347A>G (p.His116Arg), c.775T>C (p.Cys259Arg), and the third, c.1216C>T, resulting in the p.Gln406* stop codon, a type of mutation identified for the first time in GS. An Italian founder effect of the c.114delG mutation can be suggested according to the origin of the only three patients carrying this mutation reported here and in the literature. Conclusions In early reports mutations nomenclature was selected according to all CTSA isoforms (three different isoforms), thus generating a lot of confusion. In order to assist physicians in the interpretation of detected mutations, we mark the correct nomenclature for CTSA mutations. The complexity of pathology caused by the multifunctions of CTSA, and the very low numbers of mutations (only 23 overall) in relation to the length of the CTSA gene are discussed. In addition, the in silico functional predictions of all reported missense mutations allowed us to closely predict the early infantile, late infantile and juvenile phenotypes, also disclosing different degrees of severity in the juvenile phenotype. PMID:23915561

2013-01-01

166

The androgen receptor gene mutations database: 2012 update.  

PubMed

The current version of the androgen receptor gene (AR) mutations database is described. A major change to the database is that the nomenclature and numbering scheme now conforms to all Human Genome Variation Society norms. The total number of reported mutations has risen from 605 to 1,029 since 2004. The database now contains a number of mutations that are associated with prostate cancer (CaP) treatment regimens, while the number of AR mutations found in CaP tissues has more than doubled from 76 to 159. In addition, in a number of androgen insensitivity syndrome (AIS) and CaP cases, multiple mutations have been found within the same tissue samples. For the first time, we report on a disconnect within the AIS phenotype-genotype relationship among our own patient database, in that over 40% of our patients with a classic complete AIS or partial AIS phenotypes did not appear to have a mutation in their AR gene. The implications of this phenomenon on future locus-specific mutation database (LSDB) development are discussed, together with the concept that mutations can be associated with both loss- and gain-of-function, and the effect of multiple AR mutations within individuals. The database is available on the internet (http://androgendb.mcgill.ca), and a web-based LSDB with the variants using the Leiden Open Variation Database platform is available at http://www.lovd.nl/AR. PMID:22334387

Gottlieb, Bruce; Beitel, Lenore K; Nadarajah, Abbesha; Paliouras, Miltiadis; Trifiro, Mark

2012-05-01

167

Noninvasive detection of filaggrin gene mutations using Raman spectroscopy  

PubMed Central

Knowledge of the existence of filaggrin (FLG) gene mutations might be helpful for a subclassification of patients with atopic dermatitis (AD) which can be used to introduce individualized treatments. In this work the filaggrin content in the skin is assessed using Raman spectroscopy and the results are compared to FLG genotyping of Mexican-mestizo patients. Results showed that the 2282del4 and R501X mutations present in the European population but absent in people of Asian or African descent are also present in the Mexican-mestizo population. The results also showed that patients with filaggrin gene mutations presented lower filaggrin concentrations measured using the vector correlation of their skin Raman spectra and a fixed spectrum of pure human recombinant filaggrin, these results indicate that Raman spectroscopy may be used as a noninvasive tool to detect FLG gene mutations. PMID:22162825

González, Francisco J.; Valdes-Rodríguez, Rodrigo; Ramírez-Elías, Miguel G.; Castillo-Martínez, Claudio; Saavedra-Alanis, Victor M.; Moncada, Benjamín

2011-01-01

168

A novel aspartoacylase (ASPA) gene mutation in Canavan disease.  

PubMed

Canavan disease is a severe autosomal recessive leukodystrophy characterized by macrocephaly, ataxia, severe motor and mental retardation, dysmyelination, and progressive spongial atrophy of the brain. The human aspartoacylase (ASPA) gene, which catalyzes the deacetylation of N-acetyl-L-aspartate, is mutated in Canavan disease. In the presented family sequencing analysis for the aspartoacylase gene was performed on the blood samples of the parents as the affected child had died due to Canavan disease. After the mutation was detected, prenatal diagnosis was also performed and heterozygous Y88X mutation was detected in the fetus. In this report, we present a novel mutation Y88X within the aspartoacylase gene in a consanguineous family with an affected child diagnosed as Canavan disease. PMID:22468686

Durmaz, Asude Alpman; Akin, Haluk; Onay, Huseyin; Vahabi, Ali; Ozkinay, Ferda

2012-08-01

169

Suppression of gene 49 mutations of bacteriophage T4 by a second mutation in gene X: structure of pseudorevertant DNA.  

PubMed Central

Mutations in gene 49 of bacteriophage T4 were suppressed by a second mutation in gene X. Mapping studies located gene X between genes 41 and 42. Complementation results indicated that mutations in FdsA gene (a suppressor of gene 49 mutants) were in gene X. The intracellular pseudorevertant DNA was examined for unusual properties which could explain its successful encapsidation. After the in vivo inactivation of a temperature-sensitive gene 32 (DNA unwinding) protein, the intracellular pseudorevertant DNA was converted into DNA pieces of approximately genome size. A similar conversion was observed after in vitro digestion of pseudorevertant DNA with single-strand-specific S1 endonuclease. Appreciable quantities of oligomeric intermediates were not produced during this conversion process. These data indicate that pseudorevertant DNA contains sizable single-stranded gaps and has a conformation similar to that of wild-type DNA. The results further suggest that the suppression of gene 49 mutant abnormal DNA phenotype and the encapsidation defect by a second mutation in gene X is associated with the formation of sizable single-stranded gaps. These studies raise the possibility that single-stranded gaps may be involved directly in the DNA encapsidation process, or may act indirectly as a consequence of their effect on the organization of intracellular DNA. PMID:592466

Shah, D B; DeLorenzo, L

1977-01-01

170

Livedoid vasculopathy in a patient with lupus anticoagulant and MTHFR mutation: treatment with low-molecular-weight heparin.  

PubMed

Livedoid vasculopathy is characterized by painful purpuric lesions on the extremities which frequently ulcerate and heal with atrophic scarring. For many years, livedoid vasculopathy has been considered to be a primary vasculitic process. However, there has been evidence considering livedoid vasculopathy as an occlusive vasculopathy due to a hypercoagulable state. We present the case of livedoid vasculopathy in a 21-year-old female who had been suffering of painful lower extremity lesions of 3 years duration. The patient was found to be lupus anticoagulant positive and homozygous for methylenetetrahydrofolate reductase C677T mutation. The patient was successfully treated with low-molecular-weight heparin. PMID:22592843

Abou Rahal, Jihane; Ishak, Rim S; Otrock, Zaher K; Kibbi, Abdul-Ghani; Taher, Ali T

2012-11-01

171

Spectrum of ABCR gene mutations in autosomal recessive macular dystrophies  

Microsoft Academic Search

Stargardt disease (STGD) and late-onset fundus flavimaculatus (FFM) are autosomal recessive conditions leading to macular degenerations in childhood and adulthood, respectively. Recently, mutations of the photoreceptor cell-specific ATP binding transporter gene (ABCR) have been reported in Stargardt disease. Here, we report on the screening of the whole coding sequence of the ABCR gene in 40 unrelated STGD and 15 FFM

Jean-Michel Rozet; Sylvie Gerber; Eric Souied; Isabelle Perrault; Sophie Châtelin; Imad Ghazi; Corinne Leowski; Jean-Louis Dufier; Arnold Munnich; Josseline Kaplan; J-M Rozet

1998-01-01

172

Conditional lethal amber mutations in essential Escherichia coli genes.  

PubMed

The essential genes of microorganisms encode biological functions important for survival and thus tend to be of high scientific interest. Drugs that interfere with essential functions are likely to be interesting candidates for antimicrobials. However, these genes are hard to study genetically because knockout mutations in them are by definition inviable. We recently described a conditional mutation system in Escherichia coli that uses a plasmid to produce an amber suppressor tRNA regulated by the arabinose promoter. This suppressor was used here in the construction of amber mutations in seven essential E. coli genes. Amber stop codons were introduced as "tagalong" mutations in the flanking DNA of a downstream antibiotic resistance marker by lambda red recombination. The drug marker was removed by expression of I-SceI meganuclease, leaving a markerless mutation. We demonstrate the method with the genes frr, gcpE, lpxC, map, murA, ppa, and rpsA. We were unable to isolate an amber mutation in ftsZ. Kinetics of cell death and morphological changes were measured following removal of arabinose. As expected given the wide range of cellular mechanisms represented, different mutants showed widely different death curves. All of the mutations were bactericidal except the mutation in gcpE, which was bacteriostatic. The strain carrying an amber mutation in murA was by far the most sensitive, showing rapid killing in nonpermissive medium. The MurA protein is critical for peptidoglycan synthesis and is the target for the antibiotic fosfomycin. Such experiments may inexpensively provide valuable information for the identification and prioritization of targets for antibiotic development. PMID:15090508

Herring, Christopher D; Blattner, Frederick R

2004-05-01

173

Gene expression profile study in CFTR mutated bronchial cell lines  

Microsoft Academic Search

Cystic fibrosis (CF) is caused by mutations in the gene encoding the cystic fibrosis conductance transmembrane regulator (CFTR).\\u000a Symptoms are pancreatic insufficiency, chronic obstructive lung disease, liver disease, chronic sinusitis and infertility\\u000a in male patients. The phenotypic variability may be explained only in part by the more than 1200 CFTR mutations, which are\\u000a grouped into six different classes, according to

M. R. D'Apice; F. Amati; F. Sangiuolo; A. Farcomeni; G. Chillemi; S. Bueno; A. Desideri; G. Novelli

2006-01-01

174

Gene Mutations Gene a finite segment of DNA specified  

E-print Network

polydactyly, achondroplasia, huntington's Chorea, and retinoblastoma #12;Recessive Mutation · Recessive division. The result is dwarfism and premature aging. · Ataxia telangrectasia is a disorder of the DNA

Massey, Thomas N.

175

Gene mutations and molecularly targeted therapies in acute myeloid leukemia.  

PubMed

Acute myelogenous leukemia (AML) can progress quickly and without treatment can become fatal in a short period of time. However, over the last 30 years fine-tuning of therapeutics have increased the rates of remission and cure. Cytogenetics and mutational gene profiling, combined with the option of allogeneic hematopoietic stem cell transplantation offered in selected patients have further optimized AML treatment on a risk stratification basis in younger adults. However there is still an unmet medical need for effective therapies in AML since disease relapses in almost half of adult patients becoming refractory to salvage therapy. Improvements in the understanding of molecular biology of cancer and identification of recurrent mutations in AML provide opportunities to develop targeted therapies and improve the clinical outcome. In the spectrum of identified gene mutations, primarily targetable lesions are gain of function mutations of tyrosine kinases FLT3, JAK2 and cKIT for which specific, dual and multi-targeted small molecule inhibitors have been developed. A number of targeted compounds such as sorafenib, quizartinib, lestaurtinib, midostaurin, pacritinib, PLX3397 and CCT137690 are in clinical development. For loss-of-function gene mutations, which are mostly biomarkers of favorable prognosis, combined therapeutic approaches can maximize the therapeutic efficacy of conventional therapy. Apart from mutated gene products, proteins aberrantly overexpressed in AML appear to be clinically significant therapeutic targets. Such a molecule for which targeted inhibitors are currently in clinical development is PLK1. We review characteristic gene mutations, discuss their biological functions and clinical significance and present small molecule compounds in clinical development, which are expected to have a role in treating AML subtypes with characteristic molecular alterations. PMID:23358589

Hatzimichael, Eleftheria; Georgiou, Georgios; Benetatos, Leonidas; Briasoulis, Evangelos

2013-01-01

176

Optimization of Gene Expression through Divergent Mutational Paths  

PubMed Central

SUMMARY Adaptation under similar selective pressure often leads to comparable phenotypes. A longstanding question is whether such phenotypic repeatability entails similar (parallelism) or different genotypic changes (convergence). To better understand this, we characterized mutations that optimized expression of a plasmid-borne metabolic pathway during laboratory evolution of a bacterium. Expressing these pathway genes was essential for growth but came with substantial costs. Starting from overexpression, replicate populations founded by this bacterium all evolved to reduce expression. Despite this phenotypic repetitiveness, the underlying mutational spectrum was highly diverse. Analysis of these plasmid mutations identified three distinct means to modulate gene expression: (1) reducing the gene copy number, (2) lowering transcript stability, and (3) integration of the pathway-bearing plasmid into the host genome. Our study revealed diverse molecular changes beneath convergence to a simple phenotype. This complex genotype-phenotype mapping presents a challenge to inferring genetic evolution based solely on phenotypic changes. PMID:22832162

Chou, Hsin-Hung; Marx, Christopher J.

2012-01-01

177

Frequent mutations in chromatin-remodeling genes in pulmonary carcinoids  

PubMed Central

Pulmonary carcinoids are rare neuroendocrine tumors of the lung. The molecular alterations underlying the pathogenesis of these tumors have not been systematically studied so far. Here we perform gene copy number analysis (n=54), genome/exome (n=44) and transcriptome (n=69) sequencing of pulmonary carcinoids and observe frequent mutations in chromatin-remodeling genes. Covalent histone modifiers and subunits of the SWI/SNF complex are mutated in 40% and 22.2% of the cases respectively, with MEN1, PSIP1 and ARID1A being recurrently affected. In contrast to small-cell lung cancer and large-cell neuroendocrine tumors, TP53 and RB1 mutations are rare events, suggesting that pulmonary carcinoids are not early progenitor lesions of the highly aggressive lung neuroendocrine tumors but arise through independent cellular mechanisms. These data also suggest that inactivation of chromatin remodeling genes is sufficient to drive transformation in pulmonary carcinoids. PMID:24670920

Lu, Xin; Sun, Ruping; Ozreti?, Luka; Seidal, Danila; Zander, Thomas; Leenders, Frauke; George, Julie; Müller, Christian; Dahmen, Ilona; Pinther, Berit; Bosco, Graziella; Konrad, Kathryn; Altmüller, Janine; Nürnberg, Peter; Achter, Viktor; Lang, Ulrich; Schneider, Peter M; Bogus, Magdalena; Soltermann, Alex; Brustugun, Odd Terje; Helland, Åslaug; Solberg, Steinar; Lund-Iversen, Marius; Ansén, Sascha; Stoelben, Erich; Wright, Gavin M.; Russell, Prudence; Wainer, Zoe; Solomon, Benjamin; Field, John K; Hyde, Russell; Davies, Michael PA.; Heukamp, Lukas C; Petersen, Iver; Perner, Sven; Lovly, Christine; Cappuzzo, Federico; Travis, William D; Wolf, Jürgen; Vingron, Martin; Brambilla, Elisabeth; Haas, Stefan A.; Buettner, Reinhard; Thomas, Roman K

2014-01-01

178

Analysis of ?-globin gene mutations in the Chinese population.  

PubMed

Although ?-globin gene (HBD MIM#142000) mutations have no immediate physical consequence, it can interfere with the diagnosis of ?-thalassemia (?-thal), which can be severe. In the present study, of 40,863 samples referred for thalassemia trait screening, 167 samples with lower than expected Hb A(2) levels, in the presence or absence of a second Hb A(2) fraction, were selected for our analysis and 152 samples (0.4%) were positive for ?-globin gene mutations. Twenty-one different mutations were detected, and of these 12 have not been previously described. We found that -77 (T>C) was the most common mutation in Chinese followed by -30 (T>C), together accounting for almost 82.3% of the total number of ?-globin gene defects. Since compound heterozygotes for ?-thal and a ?-globin gene mutation may have low mean cell volume (MCV) and normal Hb A(2) levels, and therefore be overlooked as ?-thal heterozygotes, a detailed molecular analysis for both ?- and ?-thal is necessary, especially when one partner has been identified to have ?-thal trait. PMID:23215833

Liu, Na; Xie, Xing-Mei; Zhou, Jian-Ying; Li, Ru; Liao, Can; Li, Dong-Zhi

2013-01-01

179

Heterozygous prothrombin gene mutation associated with livedoid vasculopathy.  

PubMed

A 53-year-old woman presented with a chronic history of recurrent, painful ulcers, predominantly involving her lower legs. Both her clinical picture and histopathological findings were consistent with a diagnosis of livedoid vasculopathy, although she did have unusual findings of deep tender nodules and the presence of lesions over her elbows. Multiple investigations were undertaken, the only abnormality being a heterozygous mutation of the prothrombin G2021A gene. Although various coagulopathic states have been associated with livedoid vasculopathy, the finding of an associated prothrombin gene mutation is quite rare. Warfarin has ameliorated the clinical course when anti-inflammatory drugs and other anticoagulants were unhelpful. PMID:17535202

Anavekar, Namrata S; Kelly, Robert

2007-05-01

180

Pregnancy and ABCB4 gene mutation: risk of recurrent cholelithiasis.  

PubMed

Cholelithiasis is a common problem in the Western world. Recurrent gallstones after cholecystectomy, however, are rare. We describe a case of a young woman with recurrent gallstones after a laparoscopic cholecystectomy leading to cholangitis during pregnancy. Additional testing revealed an ATP-binding cassette B4 (ABCB4) gene mutation. ABCB4 gene mutations leading to a multidrug resistance (MDR)3-P-glycoprotein deficiency are related to, among other diseases, recurrent cholelithiasis. Medical treatment consists of administering oral ursodeoxycholic acid. If untreated, MDR3 deficiency can lead to progressive liver failure requiring liver transplantation. PMID:25612754

Elderman, Jan H; Ter Borg, Pieter C J; Dees, Jan; Dees, Adriaan

2015-01-01

181

MADM methods in solving group decision support system on gene mutations detection simulation  

Microsoft Academic Search

Detection of gene mutation is an activity that can provide contribution in the medical field. Detection of mutated gene is needed to avoid the diseases caused by them such as cancer. The detection of gene mutations can be performed by utilizing computer-based system. Group Decision Support System (GDSS) is a computer-based system that can be utilized in detecting human gene

Ermatita; Sri Hartati; Retantyo Wardoyo; Agus Harjoko

2010-01-01

182

Mutator gene and hereditary non-polyposis colorectal cancer  

DOEpatents

The human MSH2 gene, responsible for hereditary non-polyposis colorectal cancer, was identified by virtue of its homology to the MutS class of genes, which are involved in DNA mismatch repair. The sequence of cDNA clones of the human gene are provided, and the sequence of the gene can be used to demonstrate the existence of germ line mutations in hereditary non-polyposis colorectal cancer (HNPCC) kindreds, as well as in replication error.sup.+ (RER.sup.+) tumor cells.

de la Chapelle, Albert (Helsingfors, FI); Vogelstein, Bert (Baltimore, MD); Kinzler, Kenneth W. (Baltimore, MD)

2008-02-05

183

[Gliomas and BRCA genes mutations: fortuitous association or imputability?].  

PubMed

BRCA is a tumor suppressor gene implicated in the major mechanisms of cellular stability in every type of cell. Its mutations are described in numerous cancers, mainly breast and ovarian in women. It was also found an increase of lifetime risk of pancreas, colon, prostate cancer or lymphoma in men carriers. We report the cases of two female patients aged 40 and 58-years-old female patients and one 35-years-old male patient, with brain or medullar gliomas, carriers of a germline mutation of BRCA gene. Those gliomas were particularly aggressive and were not responding to the standard treatment, with chemo and radiotherapy. The very unusual characteristics in location and evolutive profile of these central nervous system tumors raise the question of a genetical underlying mechanism, maybe linked to the BRCA gene mutation that carry these patients. In addition, a non-fortuitous association between germline mutation of BRCA and occurrence of a glioma can be evoked according to the embryological, epidemiological and biomolecular findings noted in the literature. Other clinical and experimental studies are necessary to precise the physiopathological link existing between BRCA mutations and the occurrence of a glioma; this could have therapeutical and clinical implications in the future. PMID:25295380

Girardstein-Boccara, Laura; Mari, Véronique; Met-Domestici, Marie; Burel-Vandenbos, Fanny; Berthet, Pascaline; Paquis, Philippe; Frenay, Marc Paul; Lebrun-Frenay, Christine

2014-09-01

184

Mutational study of the MAMLD1-gene in hypospadias  

Microsoft Academic Search

Hypospadias, when the urethral opening is situated on the ventral side of the penis, is a common genital malformation in boys and is partly caused by genetic factors. Mutations in the Mastermind-like domain containing 1 (MAMLD1 or CXorf6) gene have been reported in hypospadias cases. We have performed direct sequencing of the MAMLD1 gene in 99 sporadic hypospadias cases to

Yougen Chen; Hanh T. T. Thai; Johanna Lundin; Kristina Lagerstedt-Robinson; Shengtian Zhao; Ellen Markljung; Agneta Nordenskjöld

2010-01-01

185

Mutations in the deubiquitinase gene USP8 cause Cushing's disease.  

PubMed

Cushing's disease is caused by corticotroph adenomas of the pituitary. To explore the molecular mechanisms of endocrine autonomy in these tumors, we performed exome sequencing of 10 corticotroph adenomas. We found somatic mutations in the USP8 deubiquitinase gene in 4 of 10 adenomas. The mutations clustered in the 14-3-3 protein binding motif and enhanced the proteolytic cleavage and catalytic activity of USP8. Cleavage of USP8 led to increased deubiqutination of the EGF receptor, impairing its downregulation and sustaining EGF signaling. USP8 mutants enhanced promoter activity of the gene encoding proopiomelanocortin. In summary, our data show that dominant mutations in USP8 cause Cushing's disease via activation of EGF receptor signaling. PMID:25485838

Reincke, Martin; Sbiera, Silviu; Hayakawa, Akira; Theodoropoulou, Marily; Osswald, Andrea; Beuschlein, Felix; Meitinger, Thomas; Mizuno-Yamasaki, Emi; Kawaguchi, Kohei; Saeki, Yasushi; Tanaka, Keiji; Wieland, Thomas; Graf, Elisabeth; Saeger, Wolfgang; Ronchi, Cristina L; Allolio, Bruno; Buchfelder, Michael; Strom, Tim M; Fassnacht, Martin; Komada, Masayuki

2015-01-01

186

Identification of Constrained Cancer Driver Genes Based on Mutation Timing  

PubMed Central

Cancer drivers are genomic alterations that provide cells containing them with a selective advantage over their local competitors, whereas neutral passengers do not change the somatic fitness of cells. Cancer-driving mutations are usually discriminated from passenger mutations by their higher degree of recurrence in tumor samples. However, there is increasing evidence that many additional driver mutations may exist that occur at very low frequencies among tumors. This observation has prompted alternative methods for driver detection, including finding groups of mutually exclusive mutations and incorporating prior biological knowledge about gene function or network structure. Dependencies among drivers due to epistatic interactions can also result in low mutation frequencies, but this effect has been ignored in driver detection so far. Here, we present a new computational approach for identifying genomic alterations that occur at low frequencies because they depend on other events. Unlike passengers, these constrained mutations display punctuated patterns of occurrence in time. We test this driver–passenger discrimination approach based on mutation timing in extensive simulation studies, and we apply it to cross-sectional copy number alteration (CNA) data from ovarian cancer, CNA and single-nucleotide variant (SNV) data from breast tumors and SNV data from colorectal cancer. Among the top ranked predicted drivers, we find low-frequency genes that have already been shown to be involved in carcinogenesis, as well as many new candidate drivers. The mutation timing approach is orthogonal and complementary to existing driver prediction methods. It will help identifying from cancer genome data the alterations that drive tumor progression. PMID:25569148

Sakoparnig, Thomas; Fried, Patrick; Beerenwinkel, Niko

2015-01-01

187

International team identifies critical genes mutated in stomach cancer  

Cancer.gov

An international team of scientists, led by researchers from the Duke-NUS Graduate Medical School in Singapore and National Cancer Centre of Singapore, has identified hundreds of novel genes that are mutated in stomach cancer, the second-most lethal cancer worldwide.

188

Telomere stability genes are not mutated in osteosarcoma cell lines  

Microsoft Academic Search

Osteosarcoma (OS), the most common primary bone tumor in adolescents and young adults, is characterized by a high degree of chromosomal abnormalities. Because telomeres are important for maintaining chromosomal integrity, it is plausible that germ-line or somatic mutations in the genes responsible for stabilizing the telomere complex could contribute to OS. We performed bi-directional sequence analysis in five OS cell

Sharon A. Savage; Brian J. Stewart; Jason S. Liao; Lee J. Helman; Stephen J. Chanock

2005-01-01

189

Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families  

Microsoft Academic Search

Purpose: Germline mutations in either BRCA1 or BRCA2 genes are responsible for the majority of hereditary breast and ovarian cancers. At present, over thousand distinct BRCA1 and BRCA2 mutations have been identified. Specific mutations are found to be common within particular populations, resulting from genetic founder effects. To investigate the contribution of germline mutations in these two genes to inherited

Andrea Pietschmann; Parvin Mehdipour; Morteza Atri; Wera Hofmann; S. Said Hosseini-Asl; Siegfried Scherneck; Stefan Mundlos; Hartmut Peters

2005-01-01

190

40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.  

Code of Federal Regulations, 2012 CFR

...false Detection of gene mutations in somatic cells in culture. 798.5300 Section 798.5300...5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture systems may be used to detect...

2012-07-01

191

40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.  

Code of Federal Regulations, 2010 CFR

...true Detection of gene mutations in somatic cells in culture. 798.5300 Section 798.5300...5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture systems may be used to detect...

2010-07-01

192

40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.  

...false Detection of gene mutations in somatic cells in culture. 798.5300 Section 798.5300...5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture systems may be used to detect...

2014-07-01

193

40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.  

Code of Federal Regulations, 2013 CFR

...false Detection of gene mutations in somatic cells in culture. 798.5300 Section 798.5300...5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture systems may be used to detect...

2013-07-01

194

40 CFR 798.5300 - Detection of gene mutations in somatic cells in culture.  

Code of Federal Regulations, 2011 CFR

...false Detection of gene mutations in somatic cells in culture. 798.5300 Section 798.5300...5300 Detection of gene mutations in somatic cells in culture. (a) Purpose. Mammalian cell culture systems may be used to detect...

2011-07-01

195

[Analysis of PCCA and PCCB gene mutations in patients with propionic acidemia].  

PubMed

OBJECTIVE To analyze PCCA and PCCB gene mutations in 10 Chinese patients with propionic acidemia(PA). METHODS Genomic DNA was extracted from peripheral blood leukocytes. The 39 exons and flanking sequences of the PCCA and PCCB genes were amplified with polymerase chain reaction and subjected to direct DNA sequencing. RESULTS DNA sequencing has revealed that 7 patients have carried a PCCA gene mutation, 2 patients carried PCCB gene mutation and 1 patient carried mutations in both PCCA and PCCB genes. Ten PA mutations were confirmed, including 8 affecting the PCCA gene and 2 affecting the PCCB gene. Three PCCA mutations c.245G>A, IVS15+5del5, c.1288C>T and 2 PCCB mutations c.838insC, c.1087T>C were found for the first time. CONCLUSION Among Chinese patients with propionic acidemia patients, their genetic mutations are mainly found on the PCCA gene. PMID:25636094

Chen, Zhanling; Wen, Pengqiang; Wang, Guobing; Hu, Yuhui; Liu, Xiaohong; Chen, Li; Chen, Shuli; Wan, Lisheng; Cui, Dong; Shang, Yue; Li, Chengrong

2015-02-10

196

A stochastic model of gene evolution with chaotic mutations.  

PubMed

We develop here a new class of stochastic models of gene evolution in which the mutations are chaotic, i.e. a random subset of the 64 possible trinucleotides mutates at each evolutionary time t according to some substitution probabilities. Therefore, at each time t, the numbers and the types of mutable trinucleotides are unknown. Thus, the mutation matrix changes at each time t. The chaotic model developed generalizes the standard model in which all the trinucleotides mutate at each time t. It determines the occurrence probabilities at time t of trinucleotides which chaotically mutate according to three substitution parameters associated with the three trinucleotide sites. Two theorems prove that this chaotic model has a probability vector at each time t and that it converges to a uniform probability vector identical to that of the standard model. Furthermore, four applications of this chaotic model (with a uniform random strategy for the 64 trinucleotides and with a particular strategy for the three stop codons) allow an evolutionary study of the three circular codes identified in both eukaryotic and prokaryotic genes. A circular code is a particular set of trinucleotides whose main property is the retrieval of the frames in genes locally, i.e. anywhere in genes and particularly without start codons, and automatically with a window of a few nucleotides. After a certain evolutionary time and with particular values for the three substitution parameters, the chaotic models retrieve the main statistical properties of the three circular codes observed in genes. These applications also allow an evolutionary comparison between the standard and chaotic models. PMID:18706428

Bahi, Jacques M; Michel, Christian J

2008-11-01

197

Detecting negative selection on recurrent mutations using gene genealogy  

PubMed Central

Background Whether or not a mutant allele in a population is under selection is an important issue in population genetics, and various neutrality tests have been invented so far to detect selection. However, detection of negative selection has been notoriously difficult, partly because negatively selected alleles are usually rare in the population and have little impact on either population dynamics or the shape of the gene genealogy. Recently, through studies of genetic disorders and genome-wide analyses, many structural variations were shown to occur recurrently in the population. Such “recurrent mutations” might be revealed as deleterious by exploiting the signal of negative selection in the gene genealogy enhanced by their recurrence. Results Motivated by the above idea, we devised two new test statistics. One is the total number of mutants at a recurrently mutating locus among sampled sequences, which is tested conditionally on the number of forward mutations mapped on the sequence genealogy. The other is the size of the most common class of identical-by-descent mutants in the sample, again tested conditionally on the number of forward mutations mapped on the sequence genealogy. To examine the performance of these two tests, we simulated recurrently mutated loci each flanked by sites with neutral single nucleotide polymorphisms (SNPs), with no recombination. Using neutral recurrent mutations as null models, we attempted to detect deleterious recurrent mutations. Our analyses demonstrated high powers of our new tests under constant population size, as well as their moderate power to detect selection in expanding populations. We also devised a new maximum parsimony algorithm that, given the states of the sampled sequences at a recurrently mutating locus and an incompletely resolved genealogy, enumerates mutation histories with a minimum number of mutations while partially resolving genealogical relationships when necessary. Conclusions With their considerably high powers to detect negative selection, our new neutrality tests may open new venues for dealing with the population genetics of recurrent mutations as well as help identifying some types of genetic disorders that may have escaped identification by currently existing methods. PMID:23651527

2013-01-01

198

Mutations of the tyrosinase gene produce autosomal recessive ocular albinism  

SciTech Connect

Albinism has historically been divided into ocular (OA) and oculocutaneous (OCA) types based on the presence or absence of clinically apparent skin and hair involvement in an individual with the ocular features of albinism. The major genes for OCA include the tyrosinase gene in OCA1 and the P gene in OCA2. X-linked and autosomal recessive OA have been described and the responsible genes have not been identified. We now present six Caucasian individuals who have the phenotype of autosomal recessive OA but who have OCA1 as shown by the presence of mutations of the tyrosinase. They had white or very light hair and white skin at birth, and cutaneous pigment developed in the first decade of life. At ages ranging from 1.5-23 years, hair color was dark blond to light brown. The skin had generalized pigment and well developed tan was present on the exposed arm and face skin of four. Iris pigment was present and iris translucency varied. Molecular analysis of the tyrosinase gene, using PCR amplification and direct di-deoxy sequencing showed the following mutations: E398Z/E398Q, P406S/g346a, R402E/T373K, ?/D383N, and H211N/T373K. The homozygous individual was not from a known consanguineous mating. T373K is the most common tyrosinase gene mutation in our laboratory. Three of these mutations are associated with a total loss of tyrosinase activity (g346a splice-site, T373K, and D383N), while four are associated with residual enzyme activity (H211N, R402E, E398Q, and P406S). These studies show that mutations of the tyrosinase gene can produce the phenotype of autosomal recessive OA in an individual who has normal amounts of cutaneous pigment and the ability to tan after birth. This extends the phenotypic range of OCA1 to normal cutaneous pigment after early childhood, and suggest that mutations of the tyrosinase gene account for a significant number of individuals with autosomal recessive OA.

King, R.A.; Summers, C.G.; Oetting, W.S. [Univ. of Minnesota, Minneapolis, MN (United States)] [and others

1994-09-01

199

THE GENE STRUCTURES OF SPONTANEOUS MUTATIONS AFFECTING A CAENORHABDZTZS ELEGANS MYOSIN HEAVY CHAIN GENE  

Microsoft Academic Search

We have isolated spontaneous mutations affecting the unc-54 major myosin heavy chain gene of Caenorhabditis elegans (variety Bristol). Spontaneous unc- 54 mutants occur in C. elegans populations at a frequency of approximately 3 X We have studied the gene structure of 65 independent unc-54 muta- tions using filter-transfer hybridization techniques. Most unc-54 mutations (50 of 65) exhibit no abnormalities detected

DAVID EIDE; PHILIP ANDERSON

200

Novel mutation in VCP gene causes atypical amyotrophic lateral sclerosis  

PubMed Central

Objective: To identify the genetic variant that causes autosomal dominantly inherited motor neuron disease in a 4-generation Israeli-Arab family using genetic linkage and whole exome sequencing. Methods: Genetic linkage analysis was performed in this family using Illumina single nucleotide polymorphism chips. Whole exome sequencing was then undertaken on DNA samples from 2 affected family members using an Illumina 2000 HiSeq platform in pursuit of potentially pathogenic genetic variants that comigrate with the disease in this pedigree. Variants meeting these criteria were then screened in all affected individuals. Results: A novel mutation (p.R191G) in the valosin-containing protein (VCP) gene was identified in the index family. Direct sequencing of the VCP gene in a panel of DNA from 274 unrelated individuals with familial amyotrophic lateral sclerosis (FALS) revealed 5 additional mutations. Among them, 2 were previously identified in pedigrees with a constellation of inclusion body myopathy with Paget disease of the bone and frontotemporal dementia (IBMPFD) and in FALS, and 2 other mutations (p.R159C and p.R155C) in IBMPFD alone. We did not detect VCP gene mutations in DNA from 178 cases of sporadic amyotrophic lateral sclerosis. Conclusions: We report a novel VCP mutation identified in an amyotrophic lateral sclerosis family (p.R191G) with atypical clinical features. In our experience, VCP mutations arise in approximately 1.5% of FALS cases. Our study supports the view that motor neuron disease is part of the clinical spectrum of VCP-associated disease. PMID:23152587

González-Pérez, Paloma; Cirulli, Elizabeth T.; Drory, Vivian E.; Dabby, Ron; Nisipeanu, Puiu; Carasso, Ralph L.; Sadeh, Menachem; Fox, Andrew; Festoff, Barry W.; Sapp, Peter C.; McKenna-Yasek, Diane; Goldstein, David B.

2012-01-01

201

Mutational analysis of adrenoleukodystrophy (ALD) gene in Japanese ALD patients  

SciTech Connect

Recently a putative ALD gene containing a striking homology with peroxisomal membrane protein (PMP70) has been identified. Besides childhood ALD, various clinical phenotypes have been identified with the onset in adolescence or adulthood (adrenomyeloneuropathy (AMN), adult cerebral ALD or cerebello-brainstem dominant type). The different clinical phenotypes occasionally coexist even in the same family. To investigate if there is a correlation between the clinical phenotypes and genotypes of the mutations in the ALD gene, we have analyzed 43 Japanese ALD patients. By Southern blot analysis, we identified non-overlapping deletions of 0.5 kb to 10.4 kb involving the ALD gene in 3 patients with adult onset cerebello-brainstem dominant type. By detailed direct sequence analysis, we found 4 patients who had point mutations in the coding region. An AMN patient had a point mutation leading to {sup 266}Gly{r_arrow}Arg change, and another patient with adult cerebral ALD had a 3 bp deletion resulting in the loss of glutamic acid at codon 291, which is a conserved amino acid both in ALD protein and PMP70. Two patients with childhood ALD had point mutations leading to {sup 507}Gly{r_arrow}Val, and {sup 518}Arg{r_arrow}Gln, respectively. Since amino acids from 507 to 520 are highly conserved as ATP-binding cassette transporter proteins, mutations in this region are expected to result in dramatic changes of the function of this protein. Although there is a tendancy for mutation in childhood ALD to be present within the ATP-binding site motif, we found two adult patients who had large deletions involving the region. Taken together, strong correlation between genotypes and clinical phenotypes is unlikely to exist, and some other modifying factors might well play an important role for the clinical manifestations of ALD.

Koike, R.; Onodera, O.; Tabe, H. [Miigate Univ. (Japan)] [and others

1994-09-01

202

40 CFR 799.9530 - TSCA in vitro mammalian cell gene mutation test.  

Code of Federal Regulations, 2012 CFR

...2012-07-01 false TSCA in vitro mammalian cell gene mutation test. 799.9530 Section... § 799.9530 TSCA in vitro mammalian cell gene mutation test. (a) Scope. ...section 4 of TSCA. The in vitro mammalian cell gene mutation test can be used to...

2012-07-01

203

40 CFR 799.9530 - TSCA in vitro mammalian cell gene mutation test.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 true TSCA in vitro mammalian cell gene mutation test. 799.9530 Section... § 799.9530 TSCA in vitro mammalian cell gene mutation test. (a) Scope. ...section 4 of TSCA. The in vitro mammalian cell gene mutation test can be used to...

2010-07-01

204

40 CFR 799.9530 - TSCA in vitro mammalian cell gene mutation test.  

...2014-07-01 false TSCA in vitro mammalian cell gene mutation test. 799.9530 Section... § 799.9530 TSCA in vitro mammalian cell gene mutation test. (a) Scope. ...section 4 of TSCA. The in vitro mammalian cell gene mutation test can be used to...

2014-07-01

205

40 CFR 799.9530 - TSCA in vitro mammalian cell gene mutation test.  

Code of Federal Regulations, 2013 CFR

...2013-07-01 false TSCA in vitro mammalian cell gene mutation test. 799.9530 Section... § 799.9530 TSCA in vitro mammalian cell gene mutation test. (a) Scope. ...section 4 of TSCA. The in vitro mammalian cell gene mutation test can be used to...

2013-07-01

206

40 CFR 799.9530 - TSCA in vitro mammalian cell gene mutation test.  

Code of Federal Regulations, 2011 CFR

...2011-07-01 false TSCA in vitro mammalian cell gene mutation test. 799.9530 Section... § 799.9530 TSCA in vitro mammalian cell gene mutation test. (a) Scope. ...section 4 of TSCA. The in vitro mammalian cell gene mutation test can be used to...

2011-07-01

207

TGFBI gene mutations in a Korean population with corneal dystrophy  

PubMed Central

Purpose To investigate the clinical and genetic features of Korean patients with corneal dystrophies associated with mutations in the human transforming growth factor-?-induced (TGFBI) gene. Methods In this study, 387 subjects (71 families and 89 individuals - 268 patients having TGFBI corneal dystrophies and 119 normal relatives) were assessed. All subjects underwent a complete ophthalmologic evaluation, including biomicroscopic inspection and dilated fundus examination. As a control, 100 individuals without corneal disease were selected from the general population. The polymerase chain reaction (PCR) and direct sequencing were used to screen for mutations in TGFBI. Results All subjects recruited exhibited a range of corneal dystrophies, including Thiel-Behnke corneal dystrophy (TBCD, R555Q; 6 families and 4 individuals), granular corneal dystrophy type 2 (GCD2, R124H; 61 families and 80 individuals), lattice corneal dystrophy (LCD; 4 families and 5 individuals; 7 with type 1 [R124C], and 2 with a variant [L527R, P542R]). The disease showed an autosomal dominant inheritance pattern in all families. Conclusions R124H in GCD2 was the most common mutation. GCD1 and Reis-Bucklers corneal dystrophy were not found. In the GCD2 patients there were a large number of laser refractive surgery-induced corneal opacities. A spontaneous R124H mutation was confirmed in an already mutated allele that resulted in a change from a heterozygous into a homozygous form. Also, a novel mutation, P527R, was identified in LCD. PMID:22876129

Cho, Kyong Jin; Mok, Jee Won; Na, Kyung Sun; Rho, Chang Rae; Byun, Yong Soo; Hwang, Ho Sik; Hwang, Kyu Yeon

2012-01-01

208

PEN-2 gene mutation in a familial Alzheimer's disease case.  

PubMed

Genetic evidence indicates a central role of cerebral accumulation of beta-amyloid (Abeta) in the pathogenesis of Alzheimer's disease (AD). Beside presenilin 1 and 2, three other recently discovered proteins (Aph 1, PEN 2 and nicastrin) are associated with gamma-secretase activity, the enzymatic complex generating Abeta. Alterations in genes encoding these proteins were candidates for a role in AD. The PEN 2 gene was examined for unknown mutations and polymorphisms in sporadic and familial Alzheimer patients. Samples from age-matched controls (n=253), sporadic AD (SAD, n=256) and familial AD (FAD, n=140) were screened with DHPLC methodology followed by sequencing. Scanning the gene identified for the first time a missense mutation (D90N) in a patient with FAD. Three intronic polymorphisms were also identified, one of which had a higher presence of the mutated allele in AD subjects carrying the allele epsilon4 of apolipoprotein E than controls. The pathogenic role of the PEN-2 D90N mutation in AD is not clear, but the findings might lead to new studies on its functional and genetic role. PMID:16170650

Sala Frigerio, C; Piscopo, P; Calabrese, E; Crestini, A; Malvezzi Campeggi, L; Civita di Fava, R; Fogliarino, S; Albani, D; Marcon, G; Cherchi, R; Piras, R; Forloni, G; Confaloni, A

2005-09-01

209

Identification of novel mutations in the human HPRT gene.  

PubMed

Inherited mutation of the purine salvage enzyme, hypoxanthine guanine phosphoribosyltransferase (HPRT) gives rise to Lesch-Nyhan syndrome (LNS) or Lesch-Nyhan variants (LNVs). We report three novel independent mutations in the coding region of HPRT gene: exon 3: c.141delA, p.D47fs53X; exon 5: c.400G>A, p.E134K; exon 7: c.499A>G, p.R167G from three LNS affected male patients. PMID:23473102

Nguyen, Khue Vu; Nyhan, William L

2013-01-01

210

Rapid detection of common mutations in the arylsulfatase A gene  

SciTech Connect

Metachromatic leukodystrophy (MLD), an autosomal recessive lysosomal storage disease results from a deficiency of arylsulfatase A activity. This disease is usually fatal within a few years of onset in the pediatric age group. A pseuodeficiency occurs in up to 15% of alleles in the general population which significantly decreases enzyme activity. Although there is no clinical phenotype associated with the pseudodeficiency, the decreased enzyme activity can complicate interpretation of biochemical assay results particularly in the case of potential heterozygous carriers of MLD. Two mutations have been found to be simultaneously associated with the pseudodeficiency: one at a glycosylatin site in exon 6 and one in the polyA addition signal. Another mutation, the `I` allele has been reported in up to 50% of alleles in the severe infantile onset form of MLD. The deleterious mutation in this case is in the +1 position of intron 2. In order to screen for these commonly occurring mutations in the arylsulfatase A gene, a simple combination of PCR amplification from genomic DNA and restriction enzyme digestions was developed for each situation. In the case of the pseuodeficiency mutations, oligonucleotide primers were designed which incorporated a single base mismatch 3 bases upstream from the 3{prime} end of the primer so that the presence of the mutation created new MaeIII restriction site in the case of the glycosylation site or an RsaI site in the case of the polyA site. The `I` allele mutation creates a new MvaI site without the use of mismatches. These tests have successfully detected the mutations in individuals suspected of having the pseudodeficiency on the basis of biochemical assay. The `I` allele was detected in 1 of 16 MLD alleles analyzed.

Coulter-Mackie, M.B. [Univ. of Western Ontario (Canada)]|[CPRI, London, Ontario (Canada)

1994-09-01

211

Mutations of the p53 and PTCH gene in basal cell carcinomas: UV mutation signature and strand bias  

Microsoft Academic Search

Mutations of p53 and PTCH gene, two candidate tumor suppressor genes for basal cell carcinoma (BCC), were screened in 15 cases of sporadic BCCs that developed in sun-exposed skin region in a Korean population. p53 and PTCH mutations were detected at a frequency of 33 and 40%, respectively, and the mutations were predominantly UV-signature transition, C?T transitions at dipyrimidine sites

Mi-Yeon Kim; Hyun Jeong Park; Seung-Cheol Baek; Dae Gyoo Byun; Dong Houh

2002-01-01

212

Nuclear and mitochondrial genes mutated in nonsyndromic impaired hearing.  

PubMed

Half of the cases with congenital impaired hearing are hereditary (HIH). HIH may occur as part of a multisystem disease (syndromic HIH) or as disorder restricted to the ear and vestibular system (nonsyndromic HIH). Since nonsyndromic HIH is almost exclusively caused by cochlear defects, affected patients suffer from sensorineural hearing loss. One percent of the total human genes, i.e. 300-500, are estimated to cause syndromic and nonsyndromic HIH. Of these, approximately 120 genes have been cloned thus far, approximately 80 for syndromic HIH and 42 for nonsyndromic HIH. In the majority of the cases, HIH manifests before (prelingual), and rarely after (postlingual) development of speech. Prelingual, nonsyndromic HIH follows an autosomal recessive trait (75-80%), an autosomal dominant trait (10-20%), an X-chromosomal, recessive trait (1-5%), or is maternally inherited (0-20%). Postlingual nonsyndromic HIH usually follows an autosomal dominant trait. Of the 41 mutated genes that cause nonsyndromic HIH, 15 cause autosomal dominant HIH, 15 autosomal recessive HIH, 6 both autosomal dominant and recessive HIH, 2 X-linked HIH, and 3 maternally inherited HIH. Mutations in a single gene may not only cause autosomal dominant, nonsyndromic HIH, but also autosomal recessive, nonsyndromic HIH (GJB2, GJB6, MYO6, MYO7A, TECTA, TMC1), and even syndromic HIH (CDH23, COL11A2, DPP1, DSPP, GJB2, GJB3, GJB6, MYO7A, MYH9, PCDH15, POU3F4, SLC26A4, USH1C, WFS1). Different mutations in the same gene may cause variable phenotypes within a family and between families. Most cases of recessive HIH result from mutations in a single locus, but an increasing number of disorders is recognized, in which mutations in two different genes (GJB2/GJB6, TECTA/KCNQ4), or two different mutations in a single allele (GJB2) are involved. This overview focuses on recent advances in the genetic background of nonsyndromic HIH. PMID:15850684

Finsterer, Josef; Fellinger, Johannes

2005-05-01

213

Genetic Association Analyses of Nitric Oxide Synthase Genes and Neural Tube Defects Vary by Phenotype  

PubMed Central

Neural tube defects (NTDs) are caused by improper neural tube closure during the early stages of embryonic development. NTDs are hypothesized to have a complex genetic origin and numerous candidate genes have been proposed. The nitric oxide synthase 3 (NOS3) G594T polymorphism has been implicated in risk for spina bifida, and interactions between that single nucleotide polymorphism (SNP) and the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism have also been observed. To evaluate other genetic variation in the NO pathway in the development of NTDs, we examined all three NOS genes: NOS1, NOS2, and NOS3. Using 3109 Caucasian samples in 745 families, we evaluated association in the overall dataset and within specific phenotypic subsets. Haplotype tagging SNPs in the NOS genes were tested for genetic association with NTD subtypes, both for main effects as well as for the presence of interactions with the MTHFR C677T polymorphism. Nominal main effect associations were found with all subtypes, across all three NOS genes, and interactions were observed between SNPs in all three NOS genes and MTHFR C677T. Unlike the previous report, the most significant associations in our dataset were with cranial subtypes and the AG genotype of rs4795067 in NOS2 (p = 0.0014) and the interaction between the rs9658490 G allele in NOS1 and MTHFR 677TT genotype (p = 0.0014). Our data extend the previous findings by implicating a role for all three NOS genes, independently and through interactions with MTHFR, in risk not only for spina bifida, but all NTD subtypes. PMID:24323870

Soldano, Karen L.; Garrett, Melanie E.; Cope, Heidi L.; Rusnak, J. Michael; Ellis, Nathen J.; Dunlap, Kaitlyn L.; Speer, Marcy C.; Gregory, Simon G.; Ashley-Koch, Allison E.

2014-01-01

214

Mutations of epigenetic regulatory genes are common in thymic carcinomas  

PubMed Central

Genetic alterations and etiology of thymic epithelial tumors (TETs) are largely unknown, hampering the development of effective targeted therapies for patients with TETs. Here TETs of advanced-stage patients enrolled in a clinical trial of molecularly-guided targeted therapies were employed for targeted sequencing of 197 cancer-associated genes. Comparative sequence analysis of 78?TET/blood paired samples obtained from 47 thymic carcinoma (TC) and 31 thymoma patients revealed a total of 86 somatic non-synonymous sequence variations across 39 different genes in 33 (42%) TETs. TCs (62%; 29/47) showed higher incidence of somatic non-synonymous mutations than thymomas (13%; 4/31; p < 0.0001). TP53 was the most frequently mutated gene in TETs (n = 13; 17%), especially in TCs (26%), and was associated with a poorer overall survival (p < 0.0001). Genes in histone modification [BAP1 (n = 6; 13%), SETD2 (n = 5; 11%), ASXL1 (n = 2; 4%)], chromatin remodeling [SMARCA4 (n = 2; 4%)], and DNA methylation [DNMT3A (n = 3; 7%), TET2 (n = 2; 4%), WT1 (n = 2; 4%)] pathways were recurrently mutated in TCs, but not in thymomas. Our results suggest a potential disruption of epigenetic homeostasis in TCs, and a substantial difference in genetic makeup between TCs and thymomas. Further investigation is warranted into the roles of epigenetic dysregulation in TC development and its potential for targeted therapy. PMID:25482724

Wang, Yisong; Thomas, Anish; Lau, Christopher; Rajan, Arun; Zhu, Yuelin; Killian, J. Keith; Petrini, Iacopo; Pham, Trung; Morrow, Betsy; Zhong, Xiaogang; Meltzer, Paul S.; Giaccone, Giuseppe

2014-01-01

215

Mutations of epigenetic regulatory genes are common in thymic carcinomas.  

PubMed

Genetic alterations and etiology of thymic epithelial tumors (TETs) are largely unknown, hampering the development of effective targeted therapies for patients with TETs. Here TETs of advanced-stage patients enrolled in a clinical trial of molecularly-guided targeted therapies were employed for targeted sequencing of 197 cancer-associated genes. Comparative sequence analysis of 78?TET/blood paired samples obtained from 47 thymic carcinoma (TC) and 31 thymoma patients revealed a total of 86 somatic non-synonymous sequence variations across 39 different genes in 33 (42%) TETs. TCs (62%; 29/47) showed higher incidence of somatic non-synonymous mutations than thymomas (13%; 4/31; p < 0.0001). TP53 was the most frequently mutated gene in TETs (n = 13; 17%), especially in TCs (26%), and was associated with a poorer overall survival (p < 0.0001). Genes in histone modification [BAP1 (n = 6; 13%), SETD2 (n = 5; 11%), ASXL1 (n = 2; 4%)], chromatin remodeling [SMARCA4 (n = 2; 4%)], and DNA methylation [DNMT3A (n = 3; 7%), TET2 (n = 2; 4%), WT1 (n = 2; 4%)] pathways were recurrently mutated in TCs, but not in thymomas. Our results suggest a potential disruption of epigenetic homeostasis in TCs, and a substantial difference in genetic makeup between TCs and thymomas. Further investigation is warranted into the roles of epigenetic dysregulation in TC development and its potential for targeted therapy. PMID:25482724

Wang, Yisong; Thomas, Anish; Lau, Christopher; Rajan, Arun; Zhu, Yuelin; Killian, J Keith; Petrini, Iacopo; Pham, Trung; Morrow, Betsy; Zhong, Xiaogang; Meltzer, Paul S; Giaccone, Giuseppe

2014-01-01

216

Ataxia telangiectasia gene mutations in leukaemia and lymphoma  

PubMed Central

Ataxia telangiectasia (AT) is a rare multisystem, autosomal, recessive disease characterised by neuronal degeneration, genome instability, and an increased risk of cancer. Approximately 10% of AT homozygotes develop cancer, mostly of the lymphoid system. Lymphoid malignancies in patients with AT are of both B cell and T cell origin, and include Hodgkin's lymphoma, non-Hodgkin's lymphoma, and several forms of leukaemia. The AT locus was mapped to the chromosomal region 11q22–23 using genetic linkage analysis in the late 1980s and the causative gene was identified by positional cloning several years later. The ATM gene encodes a large protein that belongs to a family of kinases possessing a highly conserved C-terminal kinase domain related to the phosphatidylinositol 3-kinase domain. Members of this kinase family have been shown to function in DNA repair and cell cycle checkpoint control following DNA damage. Recent studies indicate that ATM is activated primarily in response to double strand breaks and may be considered a caretaker of the genome. Most mutations in ATM result in truncation and destabilisation of the protein, but certain missense and splicing errors have been shown to produce a less severe phenotype. AT heterozygotes have a slightly increased risk of breast cancer. Atm deficient mice exhibit many of the symptoms found in patients with AT and have a high frequency of thymic lymphoma. The association between mutation of the ATM gene and a high incidence of lymphoid malignancy in patients with AT, together with the development of lymphoma in Atm deficient mice, supports the proposal that inactivation of the ATM gene may be of importance in the pathogenesis of sporadic lymphoid malignancy. Loss of heterozygosity at 11q22–23 (the location of the ATM gene) is a common event in lymphoid malignancy. Frequent inactivating mutations of the ATM gene have been reported in patients with rare sporadic T cell prolymphocytic leukaemia (T-PLL), B cell chronic lymphocytic leukaemia (B-CLL), and most recently, mantle cell lymphoma (MCL). In contrast to the ATM mutation pattern in AT, the most frequent nucleotide changes in these sporadic lymphoid malignancies were missense mutations. The presence of inactivating mutations, together with the deletion of the normal copy of the ATM gene in some patients with T-PLL, B-CLL, and MCL, establishes somatic inactivation of the ATM gene in the pathogenesis of lymphoid malignancies, and strongly suggests that ATM functions as a tumour suppressor. The presence of missense mutations in the germline of patients with B-CLL has been reported, suggesting that some patients with B-CLL may be constitutional AT heterozygotes. The putative hereditary predisposition of B-CLL, although intriguing, warrants further investigation. Key Words: lymphoid malignancy • mutation • ataxia telangiectasia gene PMID:11429421

Boultwood, J

2001-01-01

217

Endemic polycythemia in Russia: mutation in the VHL gene.  

PubMed

Chuvash polycythemia (CP) is an autosomal recessive condition that is endemic in the Russian mid-Volga River region of Chuvashia. We previously found that CP patients may have increased serum erythropoietin (EPO) levels, ruled out linkage to both the EPO and EPO receptor (EPOR) gene loci, and hypothesized that the defect may lie in the oxygen homeostasis pathway. We now report a study of five multiplex Chuvash families which confirms that CP is associated with significant elevations of serum EPO levels and rules out a location for the CP gene on chromosome 11 as had been reported by other investigators or a mutation of the HIF-1 alpha gene. Using a genome-wide screen, we localized a region on chromosome 3 with a LOD score >2. After sequencing three candidate genes, we identified a C to T transition at nucleotide 598 (an R200W mutation) in the von Hippel-Lindau (VHL) gene. The VHL protein (pVHL) downregulates the alpha subunit of hypoxia-inducible factor 1 (HIF-1 alpha), the main regulator of hypoxia adaptation, by targeting the protein for degradation. In the simplest scenario, disruption of pVHL function causes a failure to degrade HIF-1 alpha resulting in accumulation of HIF-1 alpha, upregulation of downstream target genes such as EPO, and the clinical manifestation of polycythemia. These findings strongly suggest that CP is a congenital disorder of oxygen homeostasis. PMID:11987242

Ang, Sonny O; Chen, Hua; Gordeuk, Victor R; Sergueeva, Adelina I; Polyakova, Lydia A; Miasnikova, Galina Y; Kralovics, Robert; Stockton, David W; Prchal, Josef T

2002-01-01

218

Molecular screening of pituitary adenomas for gene mutations and rearrangements  

SciTech Connect

Although pituitary tumors arise as benign monoclonal neoplasms, genetic alterations have not readily been identified in these adenomas. The authors studied restriction fragment abnormalities involving the GH gene locus, and mutations in the p53 and H-, K-, and N-ras genes in 22 human GH cell adenomas. Twenty two nonsecretory adenomas were also examined for p53 and ras gene mutations. Seven prolactinoma DNA samples were tested for deletions in the multiple endocrine neoplasia-1 (MEN-1) locus, as well as for rearrangements in the hst gene, a member of the fibroblast growth factor family. In DNA from GH-cell adenomas, identical GH restriction patterns were detected in both pituitary and lymphocyte DNA in all patients and in one patient with a mixed GH-TSH cell adenoma. Using polymerase chain reaction (PCR)-single stranded conformation polymorphism analysis, no mutations were detected in exons 5, 6, 7 and 8 of the p53 gene in GH cell adenomas nor in 22 nonsecretory adenomas. Codons 12/13 and 61 of H-ras, K-ras, and N-ras genes were also intact on GH cell adenomas and in nonsecretory adenomas. Site-specific probes for chromosome 11q13 including, PYGM, D11S146, and INT2 were used in 7 sporadic PRL-secreting adenomas to detect deletions of the MEN-1 locus on chromosome 11. One patient was identified with a loss of 11p, and the remaining 6 patients did not demonstrate loss of heterozygosity in the pituitary 11q13 locus, compared to lymphocyte DNA. None of these patients demonstrated hst gene rearrangements which also maps to this locus. These results show that p53 and ras gene mutations are not common events in the pathogenesis of acromegaly and nonsecretory tumors. Although hst gene rearrangements and deletions of 11q13 are not associated with sporadic PRl-cell adenoma formation, a single patient was detected with a partial loss of chromosome 11, including the putative MEN-1 site. 31 refs., 5 figs., 2 tabs.

Herman, V.; Drazin, N.Z.; Gonskey, R.; Melmed, S. (Cedars-Sinai Medical Center, Los Angeles, CA (United States))

1993-07-01

219

Mutational Analysis of Angiogenin Gene in Parkinson's Disease  

PubMed Central

Mutations in the angiogenic factor, angiogenin (ANG), have been identified in patients with both familial and sporadic amyotrophic lateral sclerosis (ALS) and are thought to have a neuroprotective function. Parkinsonism has been noted in kindreds with ANG mutations and variants in the ANG gene have been found to associate with PD in two Caucasian populations. We therefore hypothesized that mutations in ANG may also contribute to idiopathic Parkinson's disease (PD). We sequenced ANG gene in a total of 1498 participants comprising 750 PD patients and 748 age/gender matched controls from Taiwan. We identified one novel synonymous substitution, c.C100T (p.L10L), in a single heterozygous state in one PD patient, which was not observed in controls. The clinical phenotypes and [99mTc]-TORDAT-SPECT images of the p.L10L carrier were similar to that seen in idiopathic PD. In addition, we also identified one common variant, c.T330G (p.G110G, rs11701), which was previously reported to associate with PD risk in Caucasians. However, the frequency of TG/GG genotype was comparable between PD cases and controls (odds ratio: 0.85, 95% confidence interval: 0.29–2.55, P?=?0.78). Our results did not support that ANG rs11701 variant is a genetic risk factor for PD in our population. We conclude that mutations in ANG are not a common cause for idiopathic PD. PMID:25386690

Chen, Meng-Ling; Wu, Ruey-Meei; Tai, Chun-Hwei; Lin, Chin-Hsien

2014-01-01

220

Common filaggrin gene mutations and risk of cervical cancer.  

PubMed

Abstract Background. As carriers of filaggrin gene (FLG) mutations may have a compromised cervical mucosal barrier against human papillomavirus infection, our primary objective was to study their risk of cervical cancer. Methods. We genotyped 586 cervical cancer patients for the two most common FLG mutations, R501X and 2282del4, using blood from the Copenhagen Hospital Biobank, Denmark. Controls (n = 8050) were genotyped in previous population-based studies. Information on cervical cancer, mortality and emigration were obtained from national registers. Odds ratios (OR) were estimated by logistic regression with adjustment for age at blood sampling, and weighted by the genotype-specific inverse probability of death between diagnosis and sampling. Hazard ratios (HR) were estimated by Cox regression with time since diagnosis as underlying time, and with adjustment for age at diagnosis and stratification by cancer stage. Results. The primary results showed that FLG mutations were not associated with the risk of cervical cancer (6.3% of cases and 7.7% of controls were carriers; OR adjusted 0.81, 95% CI 0.57-1.14; OR adjusted+ weighted 0.96, 95% CI 0.58-1.57). Among cases, FLG mutations increased mortality due to cervical cancer (HR 4.55, 95% CI 1.70-12.2), however, the association was reduced after stratification by cancer stage (HR 2.53, 95% CI 0.84-7.59). Conclusion. Carriage of FLG mutations was not associated with the risk of cervical cancer. PMID:25383447

Bager, Peter; Wohlfahrt, Jan; Sørensen, Erik; Ullum, Henrik; Høgdall, Claus Kim; Palle, Connie; Husemoen, Lise Lotte Nystrup; Linneberg, Allan; Kjær, Susanne K; Melbye, Mads; Thyssen, Jacob P

2015-02-01

221

Perspective on Genes and Mutations Causing Retinitis Pigmentosa  

PubMed Central

Exceptional progress has been made during the past two decades in identifying genes causing inherited retinal diseases such as retinitis pigmentosa. An inescapable consequence is that the relationship between genes, mutations, and clinical findings has become very complex. Success in identifying the causes of inherited retinal diseases has many implications, including a better understanding of the biological basis of vision and insights into the processes involved in retinal pathology. From a clinical point of view, there are two important questions arising from these developments: where do we stand today in finding disease-causing mutations in affected individuals, and what are the implications of this information for clinical practice? This perspective addresses these questions specifically for retinitis pigmentosa, but the observations apply generally to other forms of inherited eye disease. PMID:17296890

Daiger, Stephen P.; Bowne, Sara J.; Sullivan, Lori S.

2008-01-01

222

A new spontaneous mouse mutation in the Kcne1 gene.  

PubMed

A new mouse mutant, punk rocker (allele symbol Kcne1(pkr)), arose spontaneously on a C57BL/10J inbred strain background and is characterized by a distinctive head-tossing, circling, and ataxic phenotype. It is also profoundly and bilaterally deaf. The mutation resides in the Kcne1 gene on Chromosome (Chr) 16 and has been identified as a single base change within the coding region of the third exon. The C to T nucleotide substitution causes an arginine to be altered to a termination codon at amino acid position 67, and predictably this will result in a significantly truncated protein product. The Kcne1(pkr) mutant represents the first spontaneous mouse model for the human disorder, Jervell and Lange-Nielsen syndrome, associated with mutations in the homologous KCNE1 gene on human Chr 21. PMID:11003695

Letts, V A; Valenzuela, A; Dunbar, C; Zheng, Q Y; Johnson, K R; Frankel, W N

2000-10-01

223

Fifty-four novel mutations in the NF1 gene and integrated analyses of the mutations that modulate splicing  

PubMed Central

Neurofibromatosis type 1 (NF1) is a common autosomal dominant genetic disorder caused by mutations in the NF1 gene. One of the hallmarks of NF1 is the high mutation rate in this gene. In this study, we present 127 different NF1 mutations and 54 novel mutations detected at both the genomic DNA and mRNA level using a retrospective case series review. We found that 25.2% of these different mutations induced aberrant splicing. Of note, 40.6% of these splicing errors were caused by exonic variants. In addition, one mutation produced mosaicism in the post-transcriptional profile. However, studies investigating these splicing aberrations are limited. In order to better understand the pathogenicity of NF1 and to provide a more accurate interpretation in molecular diagnostic testing, combined computational analyses were employed to elucidate the underlying mechanisms of the variants modulating NF1 gene splicing. PMID:24789688

XU, WEIHONG; YANG, XIAO; HU, XIAOXIA; LI, SHIBO

2014-01-01

224

Hereditary pancreatitis and mutation of the trypsinogen gene.  

PubMed

Hereditary pancreatitis is a rare form of chronic recurrent pancreatitis. A family, in which 11 members had chronic pancreatitis, five had diabetes, and two had pancreatic cancer, was studied, and hereditary pancreatitis was diagnosed in all patients by demonstrating the mutation in exon 3 of the cationic trypsinogen gene (R117H). The clinical implications of genotypic analysis in hereditary pancreatitis are discussed. PMID:10208958

Weber, P; Keim, V; Zimmer, K P

1999-05-01

225

Combining gene mutation with gene expression data improves outcome prediction in myelodysplastic syndromes.  

PubMed

Cancer is a genetic disease, but two patients rarely have identical genotypes. Similarly, patients differ in their clinicopathological parameters, but how genotypic and phenotypic heterogeneity are interconnected is not well understood. Here we build statistical models to disentangle the effect of 12 recurrently mutated genes and 4 cytogenetic alterations on gene expression, diagnostic clinical variables and outcome in 124 patients with myelodysplastic syndromes. Overall, one or more genetic lesions correlate with expression levels of ~20% of all genes, explaining 20-65% of observed expression variability. Differential expression patterns vary between mutations and reflect the underlying biology, such as aberrant polycomb repression for ASXL1 and EZH2 mutations or perturbed gene dosage for copy-number changes. In predicting survival, genomic, transcriptomic and diagnostic clinical variables all have utility, with the largest contribution from the transcriptome. Similar observations are made on the TCGA acute myeloid leukaemia cohort, confirming the general trends reported here. PMID:25574665

Gerstung, Moritz; Pellagatti, Andrea; Malcovati, Luca; Giagounidis, Aristoteles; Porta, Matteo G Della; Jädersten, Martin; Dolatshad, Hamid; Verma, Amit; Cross, Nicholas C P; Vyas, Paresh; Killick, Sally; Hellström-Lindberg, Eva; Cazzola, Mario; Papaemmanuil, Elli; Campbell, Peter J; Boultwood, Jacqueline

2015-01-01

226

Sarcomeric gene mutations in sudden infant death syndrome (SIDS).  

PubMed

In developed countries, sudden infant death syndrome (SIDS) represents the most prevalent cause of death in children between 1 month and 1 year of age. SIDS is a diagnosis of exclusion, a negative autopsy which requires the absence of structural organ disease. Although investigators have confirmed that a significant percentage of SIDS cases are actually channelopathies, no data have been made available as to whether other sudden cardiac death-associated diseases, such as hypertrophic cardiomyopathy (HCM), could be responsible for some cases of SIDS. The presence of a genetic mutation in the sarcomeric protein usually affects the force of contraction of the myocyte, whose weakness is compensated with progressive hypertrophy and disarray. However, it is unclear whether in the most incipient forms, that is, first years of life, the lack of these phenotypes still confers a risk of arrhythmogenesis. The main goal of the present study is to wonder whether genetic defects in the sarcomeric proteins, previously associated with HCM, could be responsible for SIDS. We have analysed 286 SIDS cases for the most common genes implicated in HCM in adults. A total of 680 mutations localised in 16 genes were analysed by semi-automated matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF-MS) using the Sequenom MassARRAY(®) System. Ten subjects with completely normal hearts showed mutated alleles at nine of the genetic variants analysed, and one additional novel mutation was detected by conventional sequencing. Therefore, a genetic mutation associated with HCM may cause sudden cardiac death in the absence of an identifiable phenotype. PMID:22361390

Brion, Maria; Allegue, Catarina; Santori, Montserrat; Gil, Rocio; Blanco-Verea, Alejandro; Haas, Cordula; Bartsch, Christine; Poster, Simone; Madea, Burkhard; Campuzano, Oscar; Brugada, Ramon; Carracedo, Angel

2012-06-10

227

Clinical and Neuropathological Features of the Arctic APP Gene Mutation Causing Early-Onset Alzheimer Disease  

Microsoft Academic Search

Background: A majority of mutations within the - amyloid region of the amyloid precursor protein (APP) gene cause inherited forms of intracerebral hemor- rhage. Most of these mutations may also cause cognitive impairment, but the Arctic APP mutation is the only known intra--amyloid mutation to date causing the more typical clinical picture of Alzheimer disease. Objective: To describe features of

Hans Basun; Nenad Bogdanovic; Martin Ingelsson; Ove Almkvist; Jan Naslund; Karin Axelman; Thomas D. Bird; David Nochlin; Gerard D. Schellenberg; Lars-Olof Wahlund; Lars Lannfelt

2008-01-01

228

Mutational analysis of genes coding for cell surface proteins in colorectal cancer cell lines reveal novel altered pathways, druggable mutations and mutated epitopes for targeted therapy.  

PubMed

We carried out a mutational analysis of 3,594 genes coding for cell surface proteins (Surfaceome) in 23 colorectal cancer cell lines, searching for new altered pathways, druggable mutations and mutated epitopes for targeted therapy in colorectal cancer. A total of 3,944 somatic non-synonymous substitutions and 595 InDels, occurring in 2,061 (57%) Surfaceome genes were catalogued. We identified 48 genes not previously described as mutated in colorectal tumors in the TCGA database, including genes that are mutated and expressed in >10% of the cell lines (SEMA4C, FGFRL1, PKD1, FAM38A, WDR81, TMEM136, SLC36A1, SLC26A6, IGFLR1). Analysis of these genes uncovered important roles for FGF and SEMA4 signaling in colorectal cancer with possible therapeutic implications. We also found that cell lines express on average 11 druggable mutations, including frequent mutations (>20%) in the receptor tyrosine kinases AXL and EPHA2, which have not been previously considered as potential targets for colorectal cancer. Finally, we identified 82 cell surface mutated epitopes, however expression of only 30% of these epitopes was detected in our cell lines. Notwithstanding, 92% of these epitopes were expressed in cell lines with the mutator phenotype, opening new venues for the use of "general" immune checkpoint drugs in this subset of patients. PMID:25193853

Donnard, Elisa; Asprino, Paula F; Correa, Bruna R; Bettoni, Fabiana; Koyama, Fernanda C; Navarro, Fabio C P; Perez, Rodrigo O; Mariadason, John; Sieber, Oliver M; Strausberg, Robert L; Simpson, Andrew J G; Jardim, Denis L F; Reis, Luiz Fernando L; Parmigiani, Raphael B; Galante, Pedro A F; Camargo, Anamaria A

2014-10-15

229

TP53 gene mutations of lung cancer patients in upper northern Thailand and environmental risk factors  

E-print Network

TP53 gene mutations of lung cancer patients in upper northern Thailand and environmental risk mutations are observed in about 40e70% of lung cancer tissues, and the hot spot codon mu- tations factors that influence TP53 gene mutation in lung cancer patients residing areas with high lung cancer

230

Free-Radical-Induced Mutation vs Redox Regulation: Costs and Benefits of Genes in Organelles  

E-print Network

Focus Free-Radical-Induced Mutation vs Redox Regulation: Costs and Benefits of Genes in Organelles of movement of genes to the nucleus is decreased mutation: plastids and mitochondria have high volume-specific rates of re- dox reactions, producing oxygen free radicals that chemically modify DNA. These mutations

Allen, John F.

231

Analysis of delta-globin gene mutations in Greek cypriots.  

PubMed

We recently described four delta-globin gene mutations in Greek Cypriots studied by polymerase chain reaction (PCR) amplification and automated fluorescence-based DNA sequence analysis (Blood 78:3298, 1991). Selective restriction enzyme digestion of PCR products facilitated direct mutation detection. Twenty-eight additional samples from unrelated Cypriots with Hb A2 levels ranging from 0.6% to 3.6% were studied by PCR and showed the following: twelve had the delta 27 (ala-->ser) mutation, one was heterozygous for the delta IVS-2 AG-->GG change, and none had either the delta 116 (arg-->cys) or delta 141 (leu-->pro) mutations. The remaining samples were divided into two groups: 11 with borderline normal Hb A2 values that were not pursued; and four with abnormal Hb A2 values. The delta-globin genes from these four samples were sequenced and the same four changes identified in each: a C-->T at -199, a C-->T at codon 4 (thr-->ile), a silent C-->T at codon 97, and an AT deletion at position 722 in IVS-2. The codon 4 change abolishes a Ple I site whereas the codon 97 creates an Nla III site, thus facilitating rapid identification. All four changes are in cis position, suggesting that the -199 C-->T, the C-->T at codon 97, and the AT deletion in IVS-2 are neutral polymorphisms present on the codon 4 (thr-->ile) chromosome. DNA haplotype analysis suggests all five delta-globin gene mutant alleles arose independently on different chromosomal backgrounds. PMID:8364213

Trifillis, P; Kyrri, A; Kalogirou, E; Kokkofitou, A; Ioannou, P; Schwartz, E; Surrey, S

1993-09-01

232

Atrichia Caused by Mutations in the Vitamin D Receptor Gene is a Phenocopy of Generalized Atrichia Caused by Mutations in the Hairless Gene  

Microsoft Academic Search

Generalized atrichia with papules is a rare disorder characterized by loss of hair shortly after birth and development of cutaneous cysts. Mutations in the hairless gene (HR) cause this phenotype in both mouse and human. Here we present a case of atrichia with papules in a patient with a normal HAIRLESS gene but with mutations in both alleles of the

Jeffrey Miller; Karima Djabali; Tai Chen; Yaping Liu; Michael Ioffreda; Stephen Lyle; Angela M. Christiano; Michael Holick; George Cotsarelis

2001-01-01

233

BSE Case Associated with Prion Protein Gene Mutation  

PubMed Central

Bovine spongiform encephalopathy (BSE) is a transmissible spongiform encephalopathy (TSE) of cattle and was first detected in 1986 in the United Kingdom. It is the most likely cause of variant Creutzfeldt-Jakob disease (CJD) in humans. The origin of BSE remains an enigma. Here we report an H-type BSE case associated with the novel mutation E211K within the prion protein gene (Prnp). Sequence analysis revealed that the animal with H-type BSE was heterozygous at Prnp nucleotides 631 through 633. An identical pathogenic mutation at the homologous codon position (E200K) in the human Prnp has been described as the most common cause of genetic CJD. This finding represents the first report of a confirmed case of BSE with a potential pathogenic mutation within the bovine Prnp gene. A recent epidemiological study revealed that the K211 allele was not detected in 6062 cattle from commercial beef processing plants and 42 cattle breeds, indicating an extremely low prevalence of the E211K variant (less than 1 in 2000) in cattle. PMID:18787697

Richt, Jürgen A.; Hall, S. Mark

2008-01-01

234

Mutations and a polymorphism in the tuberin gene  

SciTech Connect

Two deletions and a polymorphism have been identified in the recently described tuberin gene. The tuberin gene (designated TSC2) when mutated causes tuberous sclerosis complex (TSC). Fifty-three affected individuals (30 from families with multiple affected and 23 isolated cases) were screened with the tuberin cDNA for gross deletions or rearrangements. Both deletions were found in families with multiple affected members (family designations: HOU-5 and HOU-22). The approximate size of the deletion in HOU-5 is ten kilobases and eliminates a BamHI restriction site. The deletion includes a portion of the 5{prime} half of the tuberin cDNA. The deletion in HOU-22 occurs in the 3{prime} half of the gene. The deletions are being further characterized. A HindIII restriction site polymorphism was detected by a 0.5 kilobase probe from the 5{prime} coding region of the tuberin gene in an individual from a family linked to chromosome 9 (posterior probability of linkage 93%). The polymorphism did not segregate with TSC in the family. The family had previously been shown to give negative results with multiple markers on chromosome 16. The polymorphism was also seen in one individual among a panel of 20 randomly selected unaffected individuals. Thirty-five additional affected probands (five from families and 30 isolated cases) are being tested with the tuberin cDNA. Testing for subtle mutations is our panel of 80 affected probands is underway utilizing SSCP. Additional mutations or polymorphisms detected will be reported. The tuberin cDNA was a kind gift of The European Chromosome 16 Tuberous Sclerosis Consortium.

Northup, H.; Rodriguez, J.A.; Au, K.S.; Rodriguez, E. [Univ. of Texas Medical School, Houston, TX (United States)

1994-09-01

235

The Association between MTHFR Gene Polymorphisms and Hepatocellular Carcinoma Risk: A Meta-Analysis  

PubMed Central

Background The association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and hepatocellular carcinoma (HCC) risk was inconsistent and underpowered. To clarify the effects of MTHFR gene polymorphisms on the risk of HCC, a meta-analysis of all available studies relating C677T and/or A1298C polymorphisms of MTHFR gene to the risk of HCC was conducted. Methods The authors searched PubMed, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Literature database (CBM) for the period up to July 2012. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity. Results Finally, 12 studies with 2,351 cases and 4,091 controls were included for C677T polymorphism and 6 studies with 1,333 cases and 1,878 controls were included for A1298C polymorphism. With respect to A1298C polymorphism, significantly decreased HCC risk was found in the overall population (CC vs. AA: OR?=?0.660, 95%CI 0.460–0.946, P?=?0.024; recessive model: OR?=?0.667, 95%CI?=?0.470–0.948, P?=?0.024). In subgroup analyses, significantly decreased HCC risk was found in Asian population (CC vs. AA: OR?=?0.647, 95%CI?=?0.435–0.963; P?=?0.032) and population-based studies (CC vs. AA: OR?=?0.519, 95%CI?=?0.327–0.823; P?=?0.005). With respect to C677T polymorphism, no significant association with HCC risk was demonstrated in overall and stratified analyses. Conclusions We concluded that MTHFR A1298C polymorphism may play a protective role in the carcinogenesis of HCC. Further large and well-designed studies are needed to confirm this association. PMID:23457501

Deng, Yan; Huang, Shan; Xu, Juanjuan; Li, Haiwei; Li, Shan; Zhao, Jinmin

2013-01-01

236

NIH Researchers Identify New Gene Mutation Associated with ALS and Dementia  

MedlinePLUS

... identify new gene mutation associated with ALS and dementia April 7, 2014 A rare mutation in a ... several people had been diagnosed with ALS and dementia, the investigators used exome sequencing—a technique in ...

237

Cohesin gene mutations in tumorigenesis: from discovery to clinical significance  

PubMed Central

Cohesin is a multi-protein complex composed of four core subunits (SMC1A, SMC3, RAD21, and either STAG1 or STAG2) that is responsible for the cohesion of sister chromatids following DNA replication until its cleavage during mitosis thereby enabling faithful segregation of sister chromatids into two daughter cells. Recent cancer genomics analyses have discovered a high frequency of somatic mutations in the genes encoding the core cohesin subunits as well as cohesin regulatory factors (e.g. NIPBL, PDS5B, ESPL1) in a select subset of human tumors including glioblastoma, Ewing sarcoma, urothelial carcinoma, acute myeloid leukemia, and acute megakaryoblastic leukemia. Herein we review these studies including discussion of the functional significance of cohesin inactivation in tumorigenesis and potential therapeutic mechanisms to selectively target cancers harboring cohesin mutations. [BMB Reports 2014; 47(6): 299-310] PMID:24856830

Solomon, David A.; Kim, Jung-Sik; Waldman, Todd

2014-01-01

238

Mutation screening of the HGD gene identifies a novel alkaptonuria mutation with significant founder effect and high prevalence.  

PubMed

Alkaptonuria (AKU) is an autosomal recessive disorder; caused by the mutations in the homogentisate 1, 2-dioxygenase (HGD) gene located on Chromosome 3q13.33. AKU is a rare disorder with an incidence of 1: 250,000 to 1: 1,000,000, but Slovakia and the Dominican Republic have a relatively higher incidence of 1: 19,000. Our study focused on studying the frequency of AKU and identification of HGD gene mutations in nomads. HGD gene sequencing was used to identify the mutations in alkaptonurics. For the past four years, from subjects suspected to be clinically affected, we found 16 positive cases among a randomly selected cohort of 41 Indian nomads (Narikuravar) settled in the specific area of Tamil Nadu, India. HGD gene mutation analysis showed that 11 of these patients carry the same homozygous splicing mutation c.87 + 1G > A; in five cases, this mutation was found to be heterozygous, while the second AKU-causing mutation was not identified in these patients. This result indicates that the founder effect and high degree of consanguineous marriages have contributed to AKU among nomads. Eleven positive samples were homozygous for a novel mutation c.87 + 1G > A, that abolishes an intron 2 donor splice site and most likely causes skipping of exon 2. The prevalence of AKU observed earlier seems to be highly increased in people of nomadic origin. PMID:24575791

Sakthivel, Srinivasan; Zatkova, Andrea; Nemethova, Martina; Surovy, Milan; Kadasi, Ludevit; Saravanan, Madurai P

2014-05-01

239

Adaptation to an automated platform of algorithmic combinations of advantageous mutations in genes generated using amino acid scanning mutational strategy.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Recent mutational strategies for generating and screening of genes for optimized traits, including directed evolution, domain shuffling, random mutagenesis, and site-directed mutagenesis, have been adapted for automated platforms. Here we discuss the amino acid scanning mutational strategy and its ...

240

Mutation analysis of the MSMB gene in familial prostate cancer  

PubMed Central

Background: MSMB, a gene coding for ?-microseminoprotein, has been identified as a candidate susceptibility gene for prostate cancer (PrCa) in two genome-wide association studies (GWAS). SNP rs10993994 is 2?bp upstream of the transcription initiation site of MSMB and was identified as an associated PrCa risk variant. The MSMB protein is underexpressed in PrCa and it was previously proposed to be an independent marker for the recurrence of cancer after radical prostatectomy. Methods: In this study, the coding region of this gene and 1500?bp upstream of the 5?UTR has been sequenced in germline DNA in 192 PrCa patients with family history. To evaluate the possible effects of these variants we used in silico analysis. Results: No deleterious mutations were identified, however, nine new sequence variants were found, most of these in the promoter and 5?UTR region. In silico analysis suggests that four of these SNPs are likely to have some effect on gene expression either by affecting ubiquitous or prostate-specific transcription factor (TF)-binding sites or modifying splicing efficiency. Interpretation We conclude that MSMB is unlikely to be a familial PrCa gene and propose that the high-risk alleles of the SNPs in the 5?UTR effect PrCa risk by modifying MSMB gene expression in response to hormones in a tissue-specific manner. PMID:19997100

Kote-Jarai, Z; Leongamornlert, D; Tymrakiewicz, M; Field, H; Guy, M; Al Olama, A A; Morrison, J; O'Brien, L; Wilkinson, R; Hall, A; Sawyer, E; Muir, K; Hamdy, F; Donovan, J; Neal, D; Easton, D; Eeles, R

2009-01-01

241

Genetic epidemiology of muscular dystrophies resulting from sarcoglycan gene mutations.  

PubMed Central

BACKGROUND: The autosomal recessive limb-girdle muscular dystrophies (LGMDs) are a group of genetically heterogeneous muscle diseases characterised by progressive proximal limb muscle weakness. Six different loci have been mapped and pathogenetic mutations in the genes encoding the sarcoglycan complex components (alpha-, beta-, gamma-, and delta-sarcoglycan) have been documented. LGMD patients affected with primary "sarcoglycanopathies" are classified as LGMD2D, 2E, 2C, and 2F, respectively. METHODS: A geographical area in north east Italy (2,319,147 inhabitants) was selected for a genetic epidemiological study on primary sarcoglycanopathies. Within the period 1982 to 1996, all patients living in this region and diagnosed with muscular dystrophy were seen at our centre. Immunohistochemical and immunoblot screening for alpha-sarcoglycan protein deficiency was performed on all muscle biopsies from patients with a progressive muscular dystrophy of unknown aetiology and normal dystrophin. Sarcoglycan mutation analyses were conducted on all patient muscle biopsies shown to have complete or partial absence of alpha-sarcoglycan immunostaining or a decreased quantity of alpha-sarcoglycan protein on immunoblotting. RESULTS: Two hundred and four patient muscle biopsies were screened for alpha-sarcoglycan protein deficiency and 18 biopsies showed a deficiency. Pathogenetic mutations involving one gene for sarcoglycan complex components were identified in 13 patients: alpha-sarcoglycan in seven, beta-sarcoglycan in two, gamma-sarcoglycan in four, and none in the delta-sarcoglycan gene. The overall prevalence of primary sarcoglycanopathies, as of 31 December 1996, was estimated to be 5.6 x 10(-6) inhabitants. CONCLUSION: The prevalence rate estimated in this study is the first to be obtained after biochemical and molecular genetic screening for sarcoglycan defects. PMID:9429136

Fanin, M; Duggan, D J; Mostacciuolo, M L; Martinello, F; Freda, M P; Sorarù, G; Trevisan, C P; Hoffman, E P; Angelini, C

1997-01-01

242

The gene structures of spontaneous mutations affecting a Caenorhabditis elegans myosin heavy chain gene.  

PubMed

We have isolated spontaneous mutations affecting the unc-54 major myosin heavy chain gene of Caenorhabditis elegans (variety Bristol). Spontaneous unc-54 mutants occur in C. elegans populations at a frequency of approximately 3 X 10(-7). We have studied the gene structure of 65 independent unc-54 mutations using filter-transfer hybridization techniques. Most unc-54 mutations (50 of 65) exhibit no abnormalities detected with these techniques; these mutations are small lesions affecting less than 100 base pairs. Approximately 17% of the mutations (11 of 65) are simple deletions, ranging in size from less than 100 base pairs to greater than 17 kilobases. One isolate contains two separate deletions, each of which affects unc-54. Two mutants contain tandem genetic duplications that include a portion of unc-54 and extend 8-10 kilobases beyond the 5' terminus of the mRNA. Conspicuously absent from our collection of spontaneous unc-54 mutations are any resulting from insertion of transposable genetic elements. Such mutants, if they occur, must arise at a frequency of less than 5 X 10(-9). PMID:2981757

Eide, D; Anderson, P

1985-01-01

243

Sporadic ALS is not associated with VAPB gene mutations in Southern Italy  

Microsoft Academic Search

Mutations in the Cu\\/Zn superoxide dismutase (Sod1) gene have been reported to cause adult-onset autosomal dominant Amyotrophic Lateral Sclerosis (FALS). In sporadic cases (SALS) de novo mutations in the Sod1 gene have occasionally been observed. The recent finding of a mutation in the VAMP\\/synaptobrevin-associated membrane protein B (VAPB) gene as the cause of amyotrophic lateral sclerosis (ALS8), prompted us to

Francesca Luisa Conforti; Teresa Sprovieri; Rosalucia Mazzei; Carmine Ungaro; Alessandro Tessitore; Gioacchino Tedeschi; Alessandra Patitucci; Angela Magariello; AnnaLia Gabriele; Vincenzo Labella; Isabella Laura Simone; Giovanni Majorana; Maria Rosaria Monsurrò; Paola Valentino; Maria Muglia; Aldo Quattrone

2006-01-01

244

Mutations of the synapse genes and intellectual disability syndromes.  

PubMed

Intellectual disability syndromes have been found associated to numerous mutated genes that code for proteins functionally involved in synapse formation, the regulation of dendritic spine morphology, the regulation of the synaptic cytoskeleton or the synthesis and degradation of specific synapse proteins. These studies have strongly demonstrated that even mild alterations in synapse morphology and function give rise to mild or severe alteration in intellectual abilities. Interestingly, pharmacological agents that are able to counteract these morphological and functional synaptic anomalies can also improve the symptoms of some of these conditions. This review is summarizing recent discoveries on the functions of some of the genes responsible for intellectual disability syndromes connected with synapse dysfunctions. PMID:23872408

Verpelli, Chiara; Montani, Caterina; Vicidomini, Cinzia; Heise, Christopher; Sala, Carlo

2013-11-01

245

Methylenetetrahydrofolate reductase (MTHFR) 677C>T gene polymorphism as a possible factor for reducing clinical severity of psoriasis  

PubMed Central

Methylenetetrahydrofolate reductase (MTHFR) is a crucial enzyme in homocysteine/methionine metabolism. It catalysis the formation of 5-methyltetrahydrofolate (5-methyl-THF), which is the methyl donor for synthesis of methionine from homocysteine (Hcy). Decreases in folate consumption due to MTHFR polymorphism may affect production rate of keratinocytes of which had faster reproduction rates with a continuous DNA turnover and this may affect the clinical picture of psoriasis. This study aimed to investigate correlation of C677T polymorphisms in the MTHFR gene with severity of psoriasis and to evaluate the status of plasma Hcy, folate and vitamin B12 levels in patient with chronic plaque psoriasis. The study included 60 patients with chronic plaque psoriasis. The C677T polymorphisms were genotyped using PCR (Qiagen). Psoriasis Area and Severity Index (PASI) score below 7 was defined as mild, between 7 and 12 as moderate, and above 12 as severe disease. There was a significant difference between the severity of disease classification (p<0.05) with respect to the C677T polymorphism in the MTHFR gene. Severe involvement (PASI score >12) was observed in 38.46% of wild type (CC), but only 12.50% of homozygote (TT) and 7.69% of heterozygote (CT) patients. Significant differences between gene polymorphism and Hcy levels were noted in TT and CT genotypes respectively (p=0.025 and p=0.040). Plasma Hcy, folate and vitamin B12 levels were not correlated with the PASI score. Our data indicate a possible correlation of MTHFR polymorphism with severity of psoriasis. PMID:24753765

Karabacak, Ercan; Aydin, Ersin; Ozcan, Omer; Dogan, Bilal; Gultepe, Mustafa; Cosar, Alpaslan; Muftuoglu, Tuba

2014-01-01

246

Homology modeling and molecular dynamics studies of Wilms’ tumor gene 1 frameshift mutations in exon 7  

PubMed Central

As a transcription factor, the Wilms' tumor 1 (WT1) gene plays an important role in leukemogenesis. The impact of WT1 gene mutations has been reported in acute myeloid leukemia (AML). However, the number of available studies on the spatial configuration changes following WT1 mutation is limited. In this study, we sequenced the mutation in exon 7 of the WT1 gene in 60 children with newly diagnosed AML and the spatial configuration of WT1 with frameshift mutations in exon 7 was evaluated using the software for homology modeling and optimization of molecular dynamics. Three cases with frameshift mutations in exon 7 were identified (3/60; mutation rate, 5%). One case had a mutation that had been previously described, whereas the remaining two mutations were first described in our study. Of the three cases, one case presented with antecedent myelodysplastic syndrome (MDS) and the remaining two cases exhibited primary resistance to induction chemotherapy. The spatial configuration analysis demonstrated that the three mutations affected the spatial structure of exon 7 and even affected exon 8 compared to its wild-type. This study demonstrated that the frameshift mutation in exon 7 of the WT1 gene is a poor prognostic factor for children with AML, partly through the spatial configuration changes following frameshift mutations of WT1, which highlights the structure-based function analysis and may facilitate the elucidation of the pathogenesis underlying WT1 gene mutations. PMID:24649013

HU, SHAOYAN; WANG, YING; WU, SHUIYAN; ZHANG, MINGYING; PAN, JIAN; SHEN, HONGJIE; QI, XIAOFEI; CEN, JIANNONG; CHEN, ZIXING; SHEN, BAIRONG; CHEN, RUIHUA

2013-01-01

247

The landscape of cancer genes and mutational processes in breast cancer.  

PubMed

All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease. PMID:22722201

Stephens, Philip J; Tarpey, Patrick S; Davies, Helen; Van Loo, Peter; Greenman, Chris; Wedge, David C; Nik-Zainal, Serena; Martin, Sancha; Varela, Ignacio; Bignell, Graham R; Yates, Lucy R; Papaemmanuil, Elli; Beare, David; Butler, Adam; Cheverton, Angela; Gamble, John; Hinton, Jonathan; Jia, Mingming; Jayakumar, Alagu; Jones, David; Latimer, Calli; Lau, King Wai; McLaren, Stuart; McBride, David J; Menzies, Andrew; Mudie, Laura; Raine, Keiran; Rad, Roland; Chapman, Michael Spencer; Teague, Jon; Easton, Douglas; Langerød, Anita; Lee, Ming Ta Michael; Shen, Chen-Yang; Tee, Benita Tan Kiat; Huimin, Bernice Wong; Broeks, Annegien; Vargas, Ana Cristina; Turashvili, Gulisa; Martens, John; Fatima, Aquila; Miron, Penelope; Chin, Suet-Feung; Thomas, Gilles; Boyault, Sandrine; Mariani, Odette; Lakhani, Sunil R; van de Vijver, Marc; van 't Veer, Laura; Foekens, John; Desmedt, Christine; Sotiriou, Christos; Tutt, Andrew; Caldas, Carlos; Reis-Filho, Jorge S; Aparicio, Samuel A J R; Salomon, Anne Vincent; Børresen-Dale, Anne-Lise; Richardson, Andrea L; Campbell, Peter J; Futreal, P Andrew; Stratton, Michael R

2012-06-21

248

The landscape of cancer genes and mutational processes in breast cancer  

PubMed Central

All cancers carry somatic mutations in their genomes. A subset, known as driver mutations, confer clonal selective advantage on cancer cells and are causally implicated in oncogenesis1, and the remainder are passenger mutations. The driver mutations and mutational processes operative in breast cancer have not yet been comprehensively explored. Here we examine the genomes of 100 tumours for somatic copy number changes and mutations in the coding exons of protein-coding genes. The number of somatic mutations varied markedly between individual tumours. We found strong correlations between mutation number, age at which cancer was diagnosed and cancer histological grade, and observed multiple mutational signatures, including one present in about ten per cent of tumours characterized by numerous mutations of cytosine at TpC dinucleotides. Driver mutations were identified in several new cancer genes including AKT2, ARID1B, CASP8, CDKN1B, MAP3K1, MAP3K13, NCOR1, SMARCD1 and TBX3. Among the 100 tumours, we found driver mutations in at least 40 cancer genes and 73 different combinations of mutated cancer genes. The results highlight the substantial genetic diversity underlying this common disease. PMID:22722201

Stephens, Philip J.; Tarpey, Patrick S.; Davies, Helen; Loo, Peter Van; Greenman, Chris; Wedge, David C.; Nik-Zainal, Serena; Martin, Sancha; Varela, Ignacio; Bignell, Graham R.; Yates, Lucy R.; Papaemmanuil, Elli; Beare, David; Butler, Adam; Cheverton, Angela; Gamble, John; Hinton, Jonathan; Jia, Mingming; Jayakumar, Alagu; Jones, David; Latimer, Calli; Lau, King Wai; McLaren, Stuart; McBride, David J.; Menzies, Andrew; Mudie, Laura; Raine, Keiran; Rad, Roland; Chapman, Michael Spencer; Teague, Jon; Easton, Douglas; Langerød, Anita; OSBREAC; Lee, Ming Ta Michael; Shen, Chen-Yang; Tee, Benita Tan Kiat; Huimin, Bernice Wong; Broeks, Annegien; Vargas, Ana Cristina; Turashvili, Gulisa; Martens, John; Fatima, Aquila; Miron, Penelope; Chin, Suet-Feung; Thomas, Gilles; Boyault, Sandrine; Mariani, Odette; Lakhani, Sunil R.; van de Vijver, Marc; van ’t Veer, Laura; Foekens, John; Desmedt, Christine; Sotiriou, Christos; Tutt, Andrew; Caldas, Carlos; Reis-Filho, Jorge S.; Aparicio, Samuel A. J. R.; Salomon, Anne Vincent; Børresen-Dale, Anne-Lise; Richardson, Andrea L.; Campbell, Peter J.; Futreal, P. Andrew; Stratton, Michael R.

2012-01-01

249

Mutation analysis of the Fanconi Anemia Gene FACC  

SciTech Connect

Fanconi anemia (FA) is a genetically heterogeneous autosomal recessive disorder characterized by a unique hypersensitivity of cells to DNA cross-linking agents; a gene for complementation group C (FACC) has recently been cloned. The authors have amplified FACC exons with their flanking intron sequences from genomic DNA from 174 racially and ethnically diverse families in the International Fanconi Anemia Registry and have screened for mutations by using SSCP analysis. They have identified eight different variants in 32 families; three were detected in exon 1, one in exon 4, one in intron 4, two in exon 6, and one in exon 14. Two of the eight variants, in seven families, did not segregate with the disease allele in multiplex families, suggesting that these variants represented benign polymorphisms. Disease-associated mutations in FACC were detected in a total of 25 (14.4%) of 174 families screened. The most frequent mutations were IVS4 + 4 A [yields] T (intron 4; 12 families) and 322delG (exon 1; 9 families). Other, less common mutations include Q13X in exon 1, R185X and D195V in exon 6, and L554P in exon 14. The polymorphisms were S26F in exon 1 and G139E in exon 4. All patients in the study with 322delG, Q13X, R185X, and D195V are of northern or eastern European or southern Italian ancestry, and 18 of 19 have a mild form of the disease, while the 2 patients with L554P, both from the same family, have a severe phenotype. All 19 patients with IVS4 + 4 A [yields] T have Jewish ancestry and have a severe phenotype. 19 refs., 1 fig., 3 tabs.

Verlander, P.C.; Lin, J.D.; Udono, M.U.; Zhang, Q.; Auerbach, A.D. (Rockefeller Univ., New York, NY (United States)); Gibson, R.A.; Mathew, C.G. (Guy's Hospital, London (United Kingdom))

1994-04-01

250

Founder mutation(s) in the RSPH9 gene leading to primary ciliary dyskinesia in two inbred Bedouin families.  

PubMed

A rare mutation in the RSPH9 gene leading to primary ciliary dyskinesia was previously identified in two Bedouin families, one from Israel and one from the United Arab Emirates (UAE). Herein we analyse mutation segregation in the Israeli family, present the clinical disease spectrum, and estimate mutation age in the two families. Mutation segregation was studied by restriction fragment length analysis. Mutation ages were estimated using a model of the decrease in the length of ancestral haplotypes. The mutations in each of the two families had a common ancestor less than 95 and less than 17 generations in the past. If the mutations in the two families are descended from a common ancestor, that mutation would have to have arisen at least 150 generations ago. If the Bedouin population has been roughly constant in size for at least 6000 years, it is possible that the mutations in the two families are identical by descent. If there were substantial fluctuations in the size of the Bedouin population, it is more likely that there were two independent mutations. Based on the available data, the population genetic analysis does not strongly favour one conclusion over the other. PMID:20070851

Reish, Orit; Slatkin, Montgomery; Chapman-Shimshoni, Daphne; Elizur, Arnon; Chioza, Barry; Castleman, Victoria; Mitchison, Hannah M

2010-03-01

251

Founder mutation(s) in the RSPH9 gene leading to primary ciliary dyskinesia in two inbred Bedouin families  

PubMed Central

A rare mutation in the RSPH9 gene leading to Primary Ciliary Dyskinesia was previously identified in two Bedouin families, one from Israel and one from the United Arab Emirates (UAE). Herein we analyze mutation segregation in the Israeli family, present the clinical disease spectrum, and estimate mutation age in the two families. Mutation segregation was studied by restriction fragment length analysis. Mutation ages were estimated using a model of the decrease in the length of ancestral haplotypes. The mutations in each of the two families had a common ancestor less than 95 and 17 generations in the past. If the mutations in the two families are descended from a common ancestor, that mutation would have to have arisen at least 150 generations ago. If the Bedouin population has been roughly constant in size for at least 6000 years, it is possible that the mutations in the two families are identical by descent. If there were substantial fluctuations in the size of the Bedouin population, it is more likely that there were two independent mutations. Based on the available data, the population genetic analysis does not strongly favor one conclusion over the other. PMID:20070851

Reish, Orit; Slatkin, Montgomery; Chapman-Shimshoni, Daphne; Elizur, Arnon; Chioza, Barry; Castleman, Victoria; Mitchison, Hannah M.

2010-01-01

252

Induction of skin fibrosis in mice expressing a mutated fibrillin-1 gene.  

PubMed Central

BACKGROUND: Tight skin mice (TSK) bear a mutated Fibrillin-1 (Fbn-1) gene. Genetic studies show that the TSK mutation is closely associated with the Fbn-1 locus (0-0.7 cM). A previous study showed two recombinants between the Fbn-1 locus and the TSK mutation. TSK mutation and mutated Fbn-1 gene cosegregate in F1 mice. MATERIALS AND METHODS: To elucidate the role of the mutated Fbn-1 gene in occurrence of TSK syndrome, we generated transgenic (Tg) mice expressing mutated Fbn-1 gene. In another set of experiments, we injected normal mice after birth with a plasmid bearing mutated Fbn-1 gene (pdFbn-1). RESULTS: Our results demonstrate that the pdFbn-1 Tg mice developed permanent cutaneous hyperplasia that was permanent. In mice injected as newborns with a plasmid bearing the sense pdFbn-1 gene, cutaneous hyperplasia was transient. In contrast to TSK mice, neither Tg nor mice injected with plasmid developed lung emphysema. The pdFbn-1 Tg and TSK mice spontaneously produced anti-topoisomerase I and anti-Fbn- antibodies, as do humans afflicted by scleroderma; whereas, those injected with a plasmid containing the pdFbn-1 gene produced only anti-Fbn-1 autoantibodies. CONCLUSIONS: The results suggest that, although cutaneous hyperplasia is due to mutated Fbn-1 gene, the TSK syndrome may be multifactorial. PMID:11126198

Saito, S.; Nishimura, H.; Phelps, R. G.; Wolf, I.; Suzuki, M.; Honjo, T.; Bona, C.

2000-01-01

253

Prothrombotic gene variants as risk factors of acute myocardial infarction in young women  

PubMed Central

Background Acute myocardial infarction (AMI) in young women represent an extreme phenotype associated with a higher mortality compared with similarly aged men. Prothrombotic gene variants could play a role as risk factors for AMI at young age. Methods We studied Factor V Leiden, FII G20210A, MTHFR C677T and beta-fibrinogen -455G>A variants by real-time PCR in 955 young AMI (362 females) and in 698 AMI (245 females) patients. The data were compared to those obtained in 909 unrelated subjects (458 females) from the general population of the same geographical area (southern Italy). Results In young AMI females, the allelic frequency of either FV Leiden and of FII G20210A was significantly higher versus the general population (O.R.: 3.67 for FV Leiden and O.R.: 3.84 for FII G20210A; p<0.001). Among AMI patients we showed only in males that the allelic frequency of the MTHFR C677T variant was significantly higher as compared to the general population. Such difference was due to a significantly higher frequency in AMI males of the MTHFR C677T variant homozygous genotype (O.R. 3.05). Discussion and conclusion Our data confirm that young AMI in females is a peculiar phenotype with specific risk factors as the increased plasma procoagulant activity of FV and FII. On the contrary, the homozygous state for the 677T MTHFR variant may cause increased levels of homocysteine and/or an altered folate status and thus an increased risk for AMI, particularly in males. The knowledge of such risk factors (that may be easily identified by molecular analysis) may help to improve prevention strategies for acute coronary diseases in specific risk-group subjects. PMID:23171482

2012-01-01

254

Linkage and mutational analysis of familial Alzheimer disease kindreds for the APP gene region  

Microsoft Academic Search

A large number of familial Alzheimer disease (FAD) kindreds were examined to determine whether mutations in the amyloid precursor protein (APP) gene could be responsible for the disease. Previous studies have identified three mutations at APP codon 717 which are pathogenic for Alzheimer disease (AD). Samples from affected subjects were examined for mutations in exons 16 and 17 of the

K. Kamino; L. Anderson; S. Odahl; E. Nemens; T. D. Bird; G. D. Schellenberg; E. M. Wijsman; W. Kukall; E. Larson; L. L. Heston

1992-01-01

255

CLINICAL STUDY Mutational analysis of the necdin gene in patients with  

E-print Network

with Prader­Willi syndrome. Aim: To investigate necdin gene (NDN) variants in patients with isolated by CHD7 gene mutations, responsible for CHARGE syndrome, recently associated with IHH (4). Prader­ Willi

Mellon, Pamela L.

256

The association between methylene-tetrahydrofolate reductase gene polymorphism and lung cancer risk.  

PubMed

This study aimed to determine the relation between methylene-tetrahydrofolate reductase (MTHFR) gene polymorphism and lung cancer risk and the frequency of this polymorphism. The study involved 64 lung cancer patients (the study group) with definitive diagnosis and 61 noncancerous subjects (the control group). MTHFR C677T and A1298C mutation analysis was made using DNA isolated from peripheric blood and multiplex PCR and reverse hybridization strip test. Eighty-four percent of the patients were male. The age, gender, and history of alcohol use of the patients and control group were statistically similar. While MTHFR 677T and 677C allele frequency was 0.33 and 0.67 in the patients respectively, it was 0.29 and 0.71 in the control group. The frequencies of MTHFR 1298C and 1298A were 0.33 and 0.67 in the patients, and it was 0.31 and 0.69 in the control group respectively. When MTHFR 677TT and 677CT genotypes were compared with 677CC genotype, lung cancer risk was 2.4 times higher in the 677TT genotype. When MTHFR 1298AC and 1298CC genotypes were compared with 1298AA genotype, lung cancer risk was 1.5 times higher in 1298CC genotype. According to the results, allele frequency of homozygote T and C was high in lung cancer patients. It was 3.05 and 1.29 times higher in smokers than in non-smokers, and 3.05 and 1.64 times higher in males than in females; 3.0 and 2.44 times higher in those with non-small cell lung cancer than in those with small-cell lung cancer. PMID:20532637

Arslan, Sulhattin; Karadayi, Sule; Yildirim, Malik Ejder; Ozdemir, Ozturk; Akkurt, Ibrahim

2011-02-01

257

Heterozygous germ-line mutations in the NBN gene predispose to medulloblastoma in pediatric patients  

Microsoft Academic Search

The NBN (NBS1) gene belongs to a group of double-strand break repair genes. Mutations in any of these genes cause genome instability syndromes\\u000a and contribute to carcinogenesis. NBN gene mutations cause increased tumor risk in Nijmegen breakage syndrome (NBS) homozygotes as well as in NBN heterozygotes. NBS patients develop different types of malignancies; among solid tumors, medulloblastoma (MB), an embryonal

El?bieta Ciara; Dorota Piekutowska-Abramczuk; Ewa Popowska; Wies?awa Grajkowska; S?awomir Barszcz; Danuta Perek; Bo?enna Dembowska-Bagi?ska; Marta Perek-Polnik; Ewa Kowalewska; Aneta Czaj?ska; Ma?gorzata Syczewska; Kamila Czornak; Ma?gorzata Krajewska-Walasek; Marcin Roszkowski; Krystyna H. Chrzanowska

2010-01-01

258

Mutation analysis of LMX1B gene in nail-patella syndrome patients.  

PubMed Central

Nail-patella syndrome (NPS), a pleiotropic disorder exhibiting autosomal dominant inheritance, has been studied for >100 years. Recent evidence shows that NPS is the result of mutations in the LIM-homeodomain gene LMX1B. To determine whether specific LMX1B mutations are associated with different aspects of the NPS phenotype, we screened a cohort of 41 NPS families for LMX1B mutations. A total of 25 mutations were identified in 37 families. The nature of the mutations supports the hypothesis that NPS is the result of haploinsufficiency for LMX1B. There was no evidence of correlation between aspects of the NPS phenotype and specific mutations. PMID:9837817

McIntosh, I; Dreyer, S D; Clough, M V; Dunston, J A; Eyaid, W; Roig, C M; Montgomery, T; Ala-Mello, S; Kaitila, I; Winterpacht, A; Zabel, B; Frydman, M; Cole, W G; Francomano, C A; Lee, B

1998-01-01

259

Hyperinsulinism–hyperammonaemia syndrome: novel mutations in the GLUD1 gene and genotype–phenotype correlations  

PubMed Central

Background Activating mutations in the GLUD1 gene (which encodes for the intra-mitochondrial enzyme glutamate dehydrogenase, GDH) cause the hyperinsulinism–hyperammonaemia (HI/HA) syndrome. Patients present with HA and leucine-sensitive hypoglycaemia. GDH is regulated by another intra-mitochondrial enzyme sirtuin 4 (SIRT4). Sirt4 knockout mice demonstrate activation of GDH with increased amino acid-stimulated insulin secretion. Objectives To study the genotype–phenotype correlations in patients with GLUD1 mutations. To report the phenotype and functional analysis of a novel mutation (P436L) in the GLUD1 gene associated with the absence of HA. Patients and methods Twenty patients with HI from 16 families had mutational analysis of the GLUD1 gene in view of HA (n=19) or leucine sensitivity (n=1). Patients negative for a GLUD1 mutation had sequence analysis of the SIRT4 gene. Functional analysis of the novel P436L GLUD1 mutation was performed. Results Heterozygous missense mutations were detected in 15 patients with HI/HA, 2 of which are novel (N410D and D451V). In addition, a patient with a normal serum ammonia concentration (21??mol/l) was heterozygous for a novel missense mutation P436L. Functional analysis of this mutation confirms that it is associated with a loss of GTP inhibition. Seizure disorder was common (43%) in our cohort of patients with a GLUD1 mutation. No mutations in the SIRT4 gene were identified. Conclusion Patients with HI due to mutations in the GLUD1 gene may have normal serum ammonia concentrations. Hence, GLUD1 mutational analysis may be indicated in patients with leucine sensitivity; even in the absence of HA. A high frequency of epilepsy (43%) was observed in our patients with GLUD1 mutations. PMID:19690084

Kapoor, Ritika R; Flanagan, Sarah E; Fulton, Piers; Chakrapani, Anupam; Chadefaux, Bernadette; Ben-Omran, Tawfeg; Banerjee, Indraneel; Shield, Julian P; Ellard, Sian; Hussain, Khalid

2009-01-01

260

Mutation screening of the RYR1 gene in malignant hyperthermia: Detection of a novel Tyr to ser mutation in a pedigree with associated centrl cores  

Microsoft Academic Search

The ryanodine receptor gene (RYR1) has been shown to be mutated in a small number of malignant hyperthermia (MH) predigrees. Missense mutations in this gene have also been identified in two families with central core disease (CCD), a rare myopathy closely associated with MH. In an effort to identify other RYR1 mutations responsible for MH and CCD, we used a

K. A. Quane; K. E. Keating; J. M. S. Healy

1994-01-01

261

LYS2 gene and its mutation in Kluyveromyces lactis.  

PubMed

The KlLYS2 gene, encoding the alpha-aminoadipate reductase of Kluyveromyces lactis, was isolated by complementation of a lysA1 mutant. The deduced amino acid sequence shared an identity of 73% with the LYS2 product of Saccharomyces cerevisiae. Despite the high sequence homology of the alpha-aminoadipate reductase genes, the two yeast species differently responded to the presence of alpha-aminoadipate in the medium. Wild-type S. cerevisiae is known to be sensitive to alpha-aminoadipate, but becomes resistant when mutated to lys2. In contrast, K. lactis strains were found to be naturally resistant to alpha-aminoadipate. Therefore, the positive selection procedure for the isolation of lys2 mutants on alpha-aminoadipate, as practised in S. cerevisiae, cannot be applied to K. lactis. A possible reason of this difference may be that the catalytic rate of the alpha-aminoadipate reductase differs in the two yeasts. The EMBL/Genbank Accession No. for the KlLYS2 gene is AJ504405. PMID:14587101

Alberti, Adriana; Ferrero, Iliana; Lodi, Tiziana

2003-10-30

262

Genotype/phenotype correlation of multiple endocrine neoplasia type 1 gene mutations in sporadic gastrinomas.  

PubMed

Multiple endocrine neoplasia type 1 (MEN1) gene mutations are reported in some gastrinomas occurring in patients without MEN1 as well as in some other pancreatic endocrine tumors (PETs). In some inherited syndromes phenotype-genotype correlations exist for disease severity, location, or other manifestations. The purpose of the present study was to correlate mutations of the MEN1 gene in a large cohort of patients with sporadic gastrinomas to disease activity, tumor location, extent, and growth pattern. DNA was extracted from frozen gastrinomas from 51 patients and screened by dideoxyfinger-printing (ddF) for abnormalities in the 9 coding exons and adjacent splice junctions of the MEN1 gene. Tumor DNA exhibiting abnormal ddF patterns was sequenced for mutations. The findings were correlated with clinical manifestations of the disease, primary tumor site, disease extent, and tumor growth postoperatively. Tumor growth was determined by serial imaging studies. Sixteen different MEN1 gene mutations in the 51 sporadic gastrinomas (31%) were identified (11 truncating, 4 missense, and 1 in-frame deletion). Nine of the 16 mutations were located in exon 2 compared to 7 of 16 in the remaining 8 coding exons (P = 0.005 on a per nucleotide basis). Primary pancreatic or lymph node gastrinomas with a mutation had only exon 2 mutations, whereas duodenal tumors uncommonly harbored exon 2 mutations (P = 0.011). Similarly, small primary tumors (<1 cm) more frequently contained a nonexon 2 mutation (P = 0.02). There was no difference between patients with or without a mutation with respect to clinical characteristics, primary tumor site, disease extent, or proportion of patients disease free after surgery. Postoperative tumor growth tended to be more aggressive in patients with a mutation (P = 0.09). No correlation in the rate of disease-free status or postoperative tumor growth in patients with active disease to the location of the mutation was seen. These results demonstrate that the MEN1 gene is mutated in 31% of sporadic gastrinomas, and mutations are clustered between amino acids 66-166, which differs from patients with familial MEN1, in whom mutations occur throughout the gene. The presence of an MEN1 gene mutation does not correlate with clinical characteristics of patients with gastrinomas, gastrinoma extent, or growth pattern; however, the location of the mutation differed with gastrinoma location. These data suggest that mutations in the MEN1 gene are important in a proportion of sporadic gastrinomas, but the presence or absence of these mutations will not identify the clinically important subgroups with different growth patterns. PMID:10634374

Goebel, S U; Heppner, C; Burns, A L; Marx, S J; Spiegel, A M; Zhuang, Z; Lubensky, I A; Gibril, F; Jensen, R T; Serrano, J

2000-01-01

263

Mutation in the Mismatch Repair Gene Msh6 Causes Cancer Susceptibility  

Microsoft Academic Search

Mice carrying a null mutation in the mismatch repair gene Msh6 were generated by gene targeting. Cells that were homozygous for the mutation did not produce any detectable MSH6 protein, and extracts prepared from these cells were defective for repair of single nucleotide mismatches. Repair of 1, 2, and 4 nucleotide insertion\\/deletion mismatches was unaffected. Mice that were homozygous for

Winfried Edelmann; Kan Yang; Asad Umar; Joerg Heyer; Kirkland Lau; Kunhua Fan; Wolfgang Liedtke; Paula E Cohen; Michael F Kane; James R Lipford; Nianjun Yu; Gray F Crouse; Jeffrey W Pollard; Thomas Kunkel; Martin Lipkin; Richard Kolodner; Raju Kucherlapati

1997-01-01

264

Frequent Somatic Mutations of the APC Gene in Human Pancreatic Cancer 1  

Microsoft Academic Search

The APC (adenomatous polyposis coli) gene is responsible for famil- ial adenomatous polyposis and is also associated with the development of sporadic tumors of the colon and stomach. To investigate whether or not mutations of APC play any role in tumors arising in other organs, we examined somatic mutations of this gene in sporadic (nonfamilial) renal cell carcinomas, hepatocellular carcinomas,

Akira Horii; Shuichi Nakatsuru; Yasuo Miyoshi; Hiroki Nagase; Hiroshi Ando; Akio Yanagisawa; Eiju Tsuchiya; Yo Kato; Yusuke Nakamura

265

Gene replacement without selection: regulated suppression of amber mutations in Escherichia coli  

Microsoft Academic Search

We have developed a method called ‘gene gorging’ to make precise mutations in the Escherichia coli genome at frequencies high enough (1–15%) to allow direct identification of mutants by PCR or other screen rather than by selection. Gene gorging begins by establishing a donor plasmid carrying the desired mutation in the target cell. This plasmid is linearized by in vivo

Christopher D. Herring; Jeremy D. Glasner; Frederick R. Blattner

2003-01-01

266

A novel mutation of coproporphyrinogen oxidase (CPO) gene in a Japanese family  

Microsoft Academic Search

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase\\u000a (CPO). Only 11 mutations of the gene have been reported to date as the mutations responsible for HCP. We report here a novel\\u000a mutation of the gene responsible for the disease in a Japanese family. Analysis of the polymerase chain reaction (PCR) amplified\\u000a DNA fragments

Shinji Susa; Makoto Daimon; Ikuo Yamamori; Masao Kondo; Keiichi Yamatani; Hideo Sasaki; Takeo Kato

1998-01-01

267

A novel gain-of-function mutation of c- kit gene in gastrointestinal stromal tumors  

Microsoft Academic Search

Background & Aims: The c-kit gene encodes a receptor tyrosine kinase (KIT). Recently, we found gain-of-function mutations of the c-kit gene in gastrointestinal stromal tumors (GISTs). All mutations were confined within the 11 amino acids (Lys-550 to Val-560) in the juxtamembrane domain, but one GIST showed a novel deletion-type mutation at codon 579 (Asp) in the juxtamembrane domain. The aim

Masanori Nakahara; Koji Isozaki; Seiichi Hirota; Jun-Ichiro Miyagawa; Naoko Hase-Sawada; Masahiko Taniguchi; Toshirou Nishida; Suji Kanayama; Yukihiko Kitamura; Yasuhisa Shinomura; Yuji Matsuzawa

1998-01-01

268

Mutation analysis of the spastin gene (SPG4) in patients with hereditary spastic paraparesis  

PubMed Central

BACKGROUND—Hereditary spastic paraparesis is a genetically heterogeneous condition. Recently, mutations in the spastin gene were reported in families linked to the common SPG4 locus on chromosome 2p21-22.?OBJECTIVES—To study a population of patients with hereditary spastic paraparesis for mutations in the spastin gene (SPG4) on chromosome 2p21-22.?METHODS—DNA from 32 patients (12 from families known to be linked to SPG4) was analysed for mutations in the spastin gene by single strand conformational polymorphism analysis and sequencing. All patients were also examined clinically.?RESULTS—Thirteen SPG4 mutations were identified, 11 of which are novel. These mutations include missense, nonsense, frameshift, and splice site mutations, the majority of which affect the AAA cassette. We also describe a nucleotide substitution outside this conserved region which appears to behave as a recessive mutation.?CONCLUSIONS—Recurrent mutations in the spastin gene are uncommon. This reduces the ease of mutation detection as a part of the diagnostic work up of patients with hereditary spastic paraparesis. Our findings have important implications for the presumed function of spastin and schemes for mutation detection in HSP patients.???Keywords: spastin; hereditary spastic paraparesis; mutation; recessive PMID:11015453

Lindsey, J; Lusher, M; McDermott, C; White, K; Reid, E; Rubinsztein, D; Bashir, R; Hazan, J; Shaw, P; Bushby, K

2000-01-01

269

Gene Mutation Patterns in Patients with Minimally Differentiated Acute Myeloid Leukemia?  

PubMed Central

Minimally differentiated acute myeloid leukemia (AML-M0) is a rare subtype of AML with poor prognosis. Although genetic alterations are increasingly reported in AML, the gene mutations have not been comprehensively studied in AML-M0. We aimed to examine a wide spectrum of gene mutations in patients with AML-M0 to determine their clinical relevance. Twenty gene mutations including class I, class II, class III of epigenetic regulators (IDH1, IDH2, TET2, DNMT3A, MLL-PTD, ASXL1, and EZH2), and class IV (tumor suppressor genes) were analyzed in 67 patients with AML-M0. Mutational analysis was performed with polymerase chain reaction–based assays followed by direct sequencing. The most frequent gene mutations from our data were FLT3-ITD/FLT3-TKD (28.4%), followed by mutations in IDH1/IDH2 (28.8%), RUNX1 (23.9%), N-RAS/K-RAS (12.3%), TET2 (8.2%), DNMT3A (8.1%), MLL-PTD (7.8%), and ASXL1 (6.3%). Seventy-nine percent (53/67) of patients had at least one gene mutation. Class I genes (49.3%) were the most common mutated genes, which were mutually exclusive. Class III genes of epigenetic regulators were also frequent (43.9%). In multivariate analysis, old age [hazard ratio (HR) 1.029, 95% confidence interval (CI) 1.013-1.044, P = .001) was the independent adverse factor for overall survival, and RUNX1 mutation (HR 2.326, 95% CI 0.978-5.533, P = .056) had a trend toward inferior survival. In conclusion, our study showed a high frequency of FLT3, RUNX1, and IDH mutations in AML-M0, suggesting that these mutations played a role in the pathogenesis and served as potential therapeutic targets in this rare and unfavorable subtype of AML. PMID:25022553

Kao, Hsiao-Wen; Liang, Der-Cherng; Wu, Jin-Hou; Kuo, Ming-Chung; Wang, Po-Nan; Yang, Chao-Ping; Shih, Yu-Shu; Lin, Tung-Huei; Huang, Yu-Hui; Shih, Lee-Yung

2014-01-01

270

Detecting recurrent gene mutation in interaction network context using multi-scale graph diffusion  

PubMed Central

Background Delineating the molecular drivers of cancer, i.e. determining cancer genes and the pathways which they deregulate, is an important challenge in cancer research. In this study, we aim to identify pathways of frequently mutated genes by exploiting their network neighborhood encoded in the protein-protein interaction network. To this end, we introduce a multi-scale diffusion kernel and apply it to a large collection of murine retroviral insertional mutagenesis data. The diffusion strength plays the role of scale parameter, determining the size of the network neighborhood that is taken into account. As a result, in addition to detecting genes with frequent mutations in their genomic vicinity, we find genes that harbor frequent mutations in their interaction network context. Results We identify densely connected components of known and putatively novel cancer genes and demonstrate that they are strongly enriched for cancer related pathways across the diffusion scales. Moreover, the mutations in the clusters exhibit a significant pattern of mutual exclusion, supporting the conjecture that such genes are functionally linked. Using multi-scale diffusion kernel, various infrequently mutated genes are found to harbor significant numbers of mutations in their interaction network neighborhood. Many of them are well-known cancer genes. Conclusions The results demonstrate the importance of defining recurrent mutations while taking into account the interaction network context. Importantly, the putative cancer genes and networks detected in this study are found to be significant at different diffusion scales, confirming the necessity of a multi-scale analysis. PMID:23343428

2013-01-01

271

Three novel mutations of the APC gene in Korean patients with familial adenomatous polyposis.  

PubMed

Germline mutations within the adenomatous polyposis coli (APC) gene are associated with familial adenomatous polyposis (FAP), an autosomal dominant disease predisposing individuals to colorectal cancer. Identification of APC mutations has important implications for genetic counseling and management of FAP patients. We examined the APC mutation status of 10 Korean FAP patients by polymerase chain reaction-direct sequencing method and found six APC mutations, including three novel mutations. Testing for MUTYH mutation was done for FAP patients in whom no mutation in the APC gene was identified. Three novel mutations (c.1654_1663delTCTTGGCGAG, c.3709C>T, and c.6092_6094delinsTT) and three previously reported mutations (c.3631_3632delAT, c.4438C>T, and c.4612_4613delGA) were detected. The MUTYH mutation was not detected in any of the four FAP patients without an APC mutation. This finding of three novel mutations in a group of Korean FAP patients broadens the spectrum of APC mutations. PMID:20513532

Jang, Yun Ha; Lim, Seok-Byung; Kim, Mi-Jung; Chung, Hee-Jung; Yoo, Han-Wook; Byeon, Jeong-Sik; Myung, Seung-Jae; Lee, Woochang; Chun, Sail; Min, Won-Ki

2010-07-01

272

Polymorphisms in methylenetetrahydrofolate reductase gene and risk of non-Hodgkin lymphoma in a multi-ethnic population.  

PubMed

An imbalance in folate metabolism can adversely affect DNA synthesis and methylation systems which can lead to susceptibility to non-Hodgkin lymphoma (NHL). Whether single nucleotide polymorphisms (SNPs) and their haplotypes in the methylenetetrahydrofolate reductase (MTHFR) are associated with NHL, remain inconclusive. We investigated the association between MTHFR C677T and A1298C SNPs and NHL risk in a population which is made up of Malay, Chinese and Indian ethnic subgroups. A total of 372 NHL patients and 722 controls were genotyped using the Sequenom MassARRAY platform. Our results of the pooled subjects failed to demonstrate significant association between the MTHFR C677T and A1298C SNPs with NHL and its subtypes. The results were in agreement with the previous meta-analyses. In the Indian ethnic subgroup however, single locus analysis of MTHFR A1298C appears to confer risk to NHL (Odds ratio (OR) 1.91, 95% confidence interval (95% CI) 1.22-3.00, P=0.006). The risk is almost doubled in homozygous carrier of MTHFR 1298CC (OR 4.03, 95% CI 1.56-10.43, P=0.004). Haplotype analysis revealed higher frequency of CC in the Indian NHL patients compared with controls (OR 1.86, 95% CI 1.18-2.93, P=0.007). There is lack of evidence to suggest an association between MTHFR C677T and A1298C with the risk of NHL in the Malays and Chinese. In the Indians however, the MTHFR A1298C confers risk to NHL. This study suggests ethnicity modifies the relationship between polymorphisms in the folate-metabolizing gene and NHL. PMID:24646728

Suthandiram, Sujatha; Gan, Gin Gin; Zain, Shamsul Mohd; Haerian, Batoul Sadat; Bee, Ping Chong; Lian, Lay Hoong; Chang, Kian Meng; Ong, Tee Chuan; Mohamed, Zahurin

2014-05-01

273

Identification of a novel mutation in the presenilin 1 gene in a Chinese Alzheimer's disease family.  

PubMed

This study has identified a gene mutation in a Chinese family with Alzheimer's disease (AD). Family members were screened by a set of medical examinations and neuropsychological tests. Their DNA was extracted from blood cells and sequenced for gene mutation in the amyloid precursor protein (APP), the presenilin 1 (PS1) and the presenilin 2 (PS2) genes. Genetic analysis showed that the AD patients in the family harbored a T to G missense mutation at the position 314 in exon 4 of the PS1 gene, resulting in a change of F105C in amino acid sequence. Clinical manifestation of these patients included memory loss, counting difficulty, personality change, disorientation, dyscalculia, agnosia, aphasia, and apraxia, which was similar to that of the familial AD (FAD) patients harboring other PS1 mutations. We intend to add a novel mutation F105C of the PS1 gene to the pool of FAD mutations. With the current available genetic data, mutations of the PS1 gene account for the majority of gene mutations in Chinese FAD. PMID:24737487

Deng, Bo; Lian, Yan; Wang, Xin; Zeng, Fan; Jiao, Bin; Wang, Ye-Ran; Liang, Chun-Rong; Liu, Yu-Hui; Bu, Xian-Le; Yao, Xiu-Qing; Zhu, Chi; Shen, Lu; Zhou, Hua-Dong; Zhang, Tao; Wang, Yan-Jiang

2014-10-01

274

Mutations that alter the timing and pattern of cubitus interruptus gene expression in Drosophila melanogaster  

Microsoft Academic Search

The cubitus interruptus (ci) gene is a member of the Drosophila segment polarity gene family and encodes a protein with a zinc finger domain homologous to the vertebrate Gli genes and the nematode tra-1 gene. Three classes of existing mutations in the ci locus alter the regulation of ci expression and can be used to examine ci function during development.

D. C. Slusarski; C. K. Motzny; R. Holmgren

1995-01-01

275

Is methylenetetrahydrofolate reductase (MTHFR) gene A1298C polymorphism related with varicocele risk?  

PubMed

Varicocele is one of the main reasons for male infertility the exact aetiology of which remains unclear. Methylenetetrahydrofolate reductase (MTHFR) is important for DNA synthesis and methylation, which has a key role during spermatogenesis. Numerous literature suggests that the MTHFR polymorphism may be genetic risk factors for male infertility. In this study, we evaluated C677T and A1298C MTHFR gene polymorphism frequency in patients with varicocele and normal men. A total of 107 varicocele patients and 109 fertile healthy individuals were included. Genotyping of the MTHFR gene in C677T and A1298C base pairs carried out by using real-time PCR technique and afterwards, the statistical analysis accomplished. There is a statistical difference for the frequency of 1298AA genotype in patients with varicocele compared with normal controls (P = 0.0051, OR = 2.2750). Instead, subsequently, 1298/A allel frequency in patient group was significantly higher in comparison with control group (P = 0.0174). According to our results, 1298AA genotype in MTHFR gene raises the risk of varicocele approximately 2.3 times more compared with men carrying other genotypes. The results show that genetic factors have an important role in the molecular basis of varicocele. PMID:24456105

Ucar, V B; Nami, B; Acar, H; K?l?nç, M

2015-02-01

276

Effects of MTHFR gene polymorphism on the clinical and electrophysiological characteristics of migraine  

PubMed Central

Background It was previously shown that the MTHFR gene polymorphism correlated with an increased risk of migraine, particularly migraine with aura. The substitution of cytosine for thymine at the position 677 of the MTHFR gene leads to formation of the thermolabile form of the protein and development of hyperhomocysteinemia, which increases the probability of migraine. The purpose of this study was to determine whether the replacement of C677T in the gene MTHFR influenced any particular symptoms of the disease. Methods We have analyzed clinical and electrophysiological characteristics of 83 patients with migraine (migraine with aura (MA), 19 patients, and migraine without aura (MO), 64 patients, according to the ICHD-II (2003)) taking into account their genotypes of C677T variant of MTHFR. Results We have shown that MA was significantly more prevalent among the T-allele carriers (37.2%), as compared to the ?? genotype patients (0%), ? < 0.0001. Patients with TT genotype were not only more likely to have accompanying symptoms (significant differences were found only for photophobia), but also more sensitive to migraine attack triggers. In RP-VEP test results we observed a trend that the T-allele carriers were presented with the decreased N75/P100 amplitudes and a positive habituation index, as compared to the ?? genotype patients. Conclusions Thus, according to our data, the MTHFR genotypes are associated with several clinical and electrophysiological characteristics of migraine. PMID:23915182

2013-01-01

277

Mutation analysis of Leber congenital amaurosis?associated genes in patients with retinitis pigmentosa.  

PubMed

The genetic defects underlying approximately half of all retinitis pigmentosa (RP) cases are unknown. A number of genes responsible for Leber congenital amaurosis (LCA) may also cause RP when they are mutated. Our previous study revealed that variants in the most frequently mutated nine exons accounted for approximately half of the mutations detected in a cohort of patients with LCA. The aim of the present study was to detect mutations in LCA-associated genes in patients with RP using two different strategies. Sanger sequencing was used to screen mutations in the nine exons in 293 patients with RP and exome sequencing was used to detect variants in 12 LCA-associated genes in 157 of the 293 patients with RP and then to validate the variants by Sanger sequencing. Potential pathogenic mutations were identified in four patients with early onset RP, including homozygous CRB1 mutations in two patients, compound heterozygous CRB1 mutations in one patient and compound heterozygous CEP290 mutations in one patient. The present study indicated that mutations in CEP290 may also be associated with RP but not with LCA. With the exception of CEP290, the remaining 11 genes known to be associated with LCA but not with RP are unlikely to be a common cause of RP. PMID:25377065

Shen, Tao; Guan, Liping; Li, Shiqiang; Zhang, Jianguo; Xiao, Xueshan; Jiang, Hui; Yang, Jianhua; Guo, Xiangming; Wang, Jun; Zhang, Qingjiong

2015-03-01

278

Mutations predisposing to breast cancer in 12 candidate genes in breast cancer patients from Poland.  

PubMed

A number of genes other than BRCA1 and BRCA2 have been associated with breast cancer predisposition, and extended genetic testing panels have been proposed. It is of interest to establish the full spectrum of deleterious mutations in women with familial breast cancer.We performed whole-exome sequencing of 144 women with familial breast cancer and negative for 11 Polish founder mutations in BRCA1, CHEK2 and NBS1, and we evaluated the sequences of 12 known breast cancer susceptibility genes. A truncating mutation in a breast cancer gene was detected in 24 of 144 women (17%) with familial breast cancer. A BRCA2 mutation was detected in 12 cases, a (non-founder) BRCA1 mutation was detected in 5 cases, a PALB2 mutation was detected in 4 cases and an ATM mutation was detected in 2 cases. Polish women with familial breast cancer who are negative for founder mutations in BRCA1, CHEK2 and NBS1 should be fully screened for mutations in BRCA1, BRCA2 and PALB2. The PALB2 founder mutation c.509_519delGA should be included in the panel of Polish founder mutations. PMID:25330149

Cybulski, C; Lubi?ski, J; Woko?orczyk, D; Ku?niak, W; Kashyap, A; Sopik, V; Huzarski, T; Gronwald, J; Byrski, T; Szwiec, M; Jakubowska, A; Górski, B; D?bniak, T; Narod, S A; Akbari, M R

2014-10-20

279

UNSTABLE MUTATIONS IN THE FMR1 GENE AND THE PHENOTYPES  

PubMed Central

Fragile X syndrome (FXS), a severe neurodevelopmental anomaly, and one of the earliest disorders linked to an unstable (‘dynamic’) mutation, is caused by the large (>200) CGG repeat expansions in the noncoding portion of the FMR1 (Fragile X Mental Retardation-1) gene. These expansions, termed full mutations, normally silence this gene's promoter through methylation, leading to a gross deficit of the Fragile X Mental Retardation Protein (FMRP) that is essential for normal brain development. Rare individuals with the expansion but with an unmethylated promoter (and thus, FMRP production), present a much less severe form of FXS. However, a unique feature of the relationship between the different sizes of CGG expanded tract and phenotypic changes is that smaller expansions (<200) generate a series of different clinical manifestations and/or neuropsychological changes. The major part of this chapter is devoted to those FMR1 alleles with small (55-200) CGG expansions, termed ‘premutations’, which have the potential for generating the full mutation alleles on mother-offspring transmission, on the one hand, and are associated with some phenotypic changes, on the other. Thus, the role of several factors known to determine the rate of CGG expansion in the premutation alleles is discussed first. Then, an account of various neurodevelopmental, congnitive, behavioural and physical changes reported in carriers of these small expansions is given, and possible association of these conditions with a toxicity of the elevated FMR1 gene's transcript (mRNA) is discussed. The next two sections are devoted to major and well defined clinical conditions associated with the premutation alleles. The first one is the late onset neurodegenerative disorder termed fragile X-associated tremor ataxia syndrome (FXTAS). The wide range of clinical and neuropsychological manifestations of this syndrome, and their relevance to elevated levels of the FMR1 mRNA, are described. Another distinct disorder linked to the CGG repeat expansions within the premutation range is fragile X-associated primary ovarian insufficiency (FXPOI) in females, and an account of the spectrum of manifestations of this disorder, together with the latest findings suggesting an early onset of the ovarian changes, is given. In the following section, the most recent findings concerning the possible contribution of FMR1 ‘grey zone’ alleles (those with the smallest repeat expansions overlapping with the normal range i.e., 41-54 CGGs), to the psychological and clinical manifestations, already associated with premutation alleles, are discussed. Special emphasis has been placed on the possibility that the modest elevation of ‘toxic’ FMR1 mRNA in the carriers of grey zone alleles may present an additional risk for some neurodegenerative diseases, such as those associated with parkinsonism, by synergizing with either other susceptibility genes or environmental poisons. The present status of the treatment of fragile X-related disorders, especially FXS, is presented in the last section of this chapter. Pharmacological interventions in this syndrome have recently extended beyond stimulants and antipsychotic medications, and the latest trials involving a group of GluR5 antagonists aim to ascertain if these substances have the potential to reverse some of the neurobiological abnormalities of FXS. PMID:23560306

Loesch, Danuta; Hagerman, Randi

2014-01-01

280

An Ashkenazi founder mutation in the MSH6 gene leading to HNPCC.  

PubMed

Mutations in DNA mismatch repair genes underlie lynch syndrome (HNPCC). Lynch syndrome resulting from mutations in MSH6 is considered to be attenuated in comparison to that caused by mutations in MLH1 and MSH2, thus more likely to be under diagnosed. In this study we report of a common mutation in the MSH6 gene in Ashkenazi Jews. Genetic counseling and diagnostic work-up for HNPCC was conducted in families who attended the high risk clinic for inherited cancer. We identified the mutation c.3984_3987dup in the MSH6 gene in 19 members of four unrelated Ashkenazi families. This mutation results in truncation of the transcript and in loss of expression of the MSH6 protein in tumors. Tumor spectrum among carriers included colon, endometrial, gastric, ovarian, urinary, and breast cancer. All but one family qualified for the Bethesda guidelines and none fulfilled the Amsterdam Criteria. Members of one family also co-inherited the c.6174delT mutation in the BRCA2 gene. The c.3984_3987dup in the MSH6 gene is a mutation leading to HNPCC among Ashkenazi Jews. This is most probably a founder mutation. In contrast to the c.1906G>C founder mutation in the MSH2 gene, tumors tend to occur later in life, and none of the families qualified for the Amsterdam criteria. c.3984_3987dup is responsible for 1/6 of the mutations identified among Ashkenazi HNPCC families in our cohort. Both mutations: c.3984_3987dup and c.1906G>C account for 61% of HNPCC Ashkenazi families in this cohort. These findings are of great importance for counseling, diagnosis, management and surveillance for Ashkenazi families with Lynch syndrome. PMID:19851887

Goldberg, Yael; Porat, Rinnat M; Kedar, Inbal; Shochat, Chen; Galinsky, Daliah; Hamburger, Tamar; Hubert, Ayala; Strul, Hana; Kariiv, Revital; Ben-Avi, Liat; Savion, Moran; Pikarsky, Eli; Abeliovich, Dvorah; Bercovich, Dani; Lerer, Israela; Peretz, Tamar

2010-06-01

281

De novo mutations in the BMPR2 gene in patients with heritable pulmonary arterial hypertension.  

PubMed

A substantial proportion of patients with pulmonary arterial hypertension (PAH) have mutations in the Bone Morphogenetic Protein Receptor type-2 (BMPR2) gene. PAH due to BMPR2 mutations is inherited as an autosomal dominant trait with several unique features, including a wide variety of mutations, reduced penetrance, a skewed gender ratio, variable expressivity and genetic anticipation. To address the genetic background of these unique features of BMPR2 mutation, we conducted a systematic analysis of 15 PAH families with BMPR2 mutation. The exonic protein coding sequence of BMPR2 was amplified by polymerase chain reaction and the products were sequenced directly to detect point mutations in BMPR2. Parental identification was carried out to confirm the parental relationship using multiplex 15 loci analysis. Combining mutation detection in family members with parental identification, we described three cases of de novo mutation in the BMPR2 gene by different modes in a PAH family. These de novo mutations may account for the wide variety of mutations in BMPR2. Taken together with the juvenile onset of the disease, there is possibly some balance of de novo mutations and untransmittable mutations which keeps the frequency of PAH low in the general population. PMID:25612240

Momose, Yuichi; Aimi, Yuki; Hirayama, Tomomi; Kataoka, Masaharu; Ono, Masae; Yoshino, Hideaki; Satoh, Toru; Gamou, Shinobu

2015-03-01

282

p53 Gene Mutations Occur in Combination with 17p Allelic Deletions as Late Events in Colorectal Tumorigenesis1  

Microsoft Academic Search

Coordinate loss of one copy of the p53 gene and mutation of the remaining copy occur in colorectal carcinomas and in many other human malignancies. However, the prevalence of p53 gene mutations in carci nomas which maintain both parental copies of p53 has not previously been evaluated. Moreover, it is not known whether p53 gene mutations are limited to malignant

Suzanne J. Baker; Antonette C. Preisinger; J. Milburn Jessup; Christos Paraskeva; Sanford Markowitz; J. K. V. Willson; Bert Vogelstein

1990-01-01

283

Polymorphism analysis and new JAG1 gene mutations of Alagille syndrome in Mexican population?  

PubMed Central

Alagille syndrome is a multisystem disorder with an autosomic dominant pattern of inheritance that affects the liver, heart, eyes, kidneys, skeletal system and presents characteristic facial features. Mutations of the JAG1 gene have been identified in 20–89% of the patients with Alagille syndrome, this gene encodes for a ligand that activates the Notch signaling pathway. In the present study we analyzed 9 Mexican patients with Alagille syndrome who presented the clinical criteria for the classical presentation of the disease. By using the denaturing high performance liquid chromatography mutation analysis we were able to identify different mutations in 7 of the patients (77.77%), importantly, we found 5 novel mutations in JAG1 gene. The allelic frequency distribution of 13 polymorphisms in Mexican population is also reported. The overall results demonstrated an expanding mutational spectrum of JAG1 gene in the Mexican population. PMID:25606387

Vázquez-Martínez, Edgar Ricardo; Varela-Fascinetto, Gustavo; García-Delgado, Constanza; Rodríguez-Espino, Benjamín Antonio; Sánchez-Boiso, Adriana; Valencia-Mayoral, Pedro; Heller-Rosseau, Solange; Pelcastre-Luna, Erika Lisselly; Zenteno, Juan C.; Cerbón, Marco; Morán-Barroso, Verónica Fabiola

2013-01-01

284

Polymorphism analysis and new JAG1 gene mutations of Alagille syndrome in Mexican population.  

PubMed

Alagille syndrome is a multisystem disorder with an autosomic dominant pattern of inheritance that affects the liver, heart, eyes, kidneys, skeletal system and presents characteristic facial features. Mutations of the JAG1 gene have been identified in 20-89% of the patients with Alagille syndrome, this gene encodes for a ligand that activates the Notch signaling pathway. In the present study we analyzed 9 Mexican patients with Alagille syndrome who presented the clinical criteria for the classical presentation of the disease. By using the denaturing high performance liquid chromatography mutation analysis we were able to identify different mutations in 7 of the patients (77.77%), importantly, we found 5 novel mutations in JAG1 gene. The allelic frequency distribution of 13 polymorphisms in Mexican population is also reported. The overall results demonstrated an expanding mutational spectrum of JAG1 gene in the Mexican population. PMID:25606387

Vázquez-Martínez, Edgar Ricardo; Varela-Fascinetto, Gustavo; García-Delgado, Constanza; Rodríguez-Espino, Benjamín Antonio; Sánchez-Boiso, Adriana; Valencia-Mayoral, Pedro; Heller-Rosseau, Solange; Pelcastre-Luna, Erika Lisselly; Zenteno, Juan C; Cerbón, Marco; Morán-Barroso, Verónica Fabiola

2014-12-01

285

The presence of MEFV gene mutations in patients with primary osteoarthritis who require surgery  

PubMed Central

Background/Aims Chronic arthritis of familial Mediterranean fever (FMF) involves weight-bearing joints and can occur in patients without a history of acute attack. Our aim was to investigate a possible causal relationship between FMF and osteoarthritis in a population in which FMF is quite common. Methods Patients with late stage primary osteoarthritis were enrolled, and five MEFV gene mutations were investigated. The frequency of MEFV gene mutations was compared among patients with osteoarthritis and a previous healthy group from our center. Results One hundred patients with primary osteoarthritis and 100 healthy controls were studied. The frequency of MEFV gene mutations was significantly lower in the osteoarthritis group (9% vs. 19%). M694V was the most frequent mutation (5%) in the osteoarthritis group, whereas in the control group, E148Q was the most common (16%). In subgroup analyses, the mutation frequency of patients with hip osteoarthritis was not different from that of patients with knee osteoarthritis and controls (7.1%, 9.7%, and 19%, respectively). There were no differences among the three groups with respect to MEFV gene mutations other than E148Q (8.1% vs. 3.6%). E148Q was significantly lower in the osteoarthritis group than in the controls (16% vs. 1%), although the mutations did not differ between patients with knee osteoarthritis and controls. Conclusions In a population with a high prevalence of MEFV gene mutations, we did not find an increased mutation rate in patients with primary osteoarthritis. Furthermore, we found that some mutations were significantly less frequent in patients with osteoarthritis. Although the number of patients studied was insufficient to claim that E148Q gene mutation protects against osteoarthritis, the potential of this gene merits further investigation. PMID:24009456

Erdem, Hakan; Tunay, Servet; Torun, Deniz; Genc, Halil; Tunca, Yusuf; Karadag, Omer; Simsek, Ismail; Bahce, Muhterem; Pay, Salih; Dinc, Ayhan

2013-01-01

286

Software and database for the analysis of mutations in the human FBN1 gene.  

PubMed Central

Fibrillin is the major component of extracellular microfibrils. Mutations in the fibrillin gene on chromosome 15 (FBN1) were described at first in the heritable connective tissue disorder, Marfan syndrome (MFS). More recently, FBN1 has also been shown to harbor mutations related to a spectrum of conditions phenotypically related to MFS and many mutations will have to be accumulated before genotype/phenotype relationships emerge. To facilitate mutational analysis of the FBN1 gene, a software package along with a computerized database (currently listing 63 entries) have been created. PMID:8594563

Collod, G; Béroud, C; Soussi, T; Junien, C; Boileau, C

1996-01-01

287

Novel mutations of PKD genes in the Czech population with autosomal dominant polycystic kidney disease  

PubMed Central

Background Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary renal disorder caused by mutation in either one of two genes, PKD1 and PKD2. High structural and sequence complexity of PKD genes makes the mutational diagnostics of ADPKD challenging. The present study is the first detailed analysis of both PKD genes in a cohort of Czech patients with ADPKD using High Resolution Melting analysis (HRM) and Multiplex Ligation-dependent Probe Amplification (MLPA). Methods The mutational analysis of PKD genes was performed in a set of 56 unrelated patients. For mutational screening of the PKD1 gene, the long-range PCR (LR-PCR) strategy followed by nested PCR was used. Resulting PCR fragments were analyzed by HRM; the positive cases were reanalyzed and confirmed by direct sequencing. Negative samples were further examined for sequence changes in the PKD2 gene by the method of HRM and for large rearrangements of both PKD1 and PKD2 genes by MLPA. Results Screening of the PKD1 gene revealed 36 different likely pathogenic germline sequence changes in 37 unrelated families/individuals. Twenty-five of these sequence changes were described for the first time. Moreover, a novel large deletion was found within the PKD1 gene in one patient. Via the mutational analysis of the PKD2 gene, two additional likely pathogenic mutations were detected. Conclusions Probable pathogenic mutation was detected in 71% of screened patients. Determination of PKD mutations and their type and localization within corresponding genes could help to assess clinical prognosis of ADPKD patients and has major benefit for prenatal and/or presymptomatic or preimplantational diagnostics in affected families as well. PMID:24694054

2014-01-01

288

EpilepsyGene: a genetic resource for genes and mutations related to epilepsy.  

PubMed

Epilepsy is one of the most prevalent chronic neurological disorders, afflicting about 3.5-6.5 per 1000 children and 10.8 per 1000 elderly people. With intensive effort made during the last two decades, numerous genes and mutations have been published to be associated with the disease. An organized resource integrating and annotating the ever-increasing genetic data will be imperative to acquire a global view of the cutting-edge in epilepsy research. Herein, we developed EpilepsyGene (http://61.152.91.49/EpilepsyGene). It contains cumulative to date 499 genes and 3931 variants associated with 331 clinical phenotypes collected from 818 publications. Furthermore, in-depth data mining was performed to gain insights into the understanding of the data, including functional annotation, gene prioritization, functional analysis of prioritized genes and overlap analysis focusing on the comorbidity. An intuitive web interface to search and browse the diversified genetic data was also developed to facilitate access to the data of interest. In general, EpilepsyGene is designed to be a central genetic database to provide the research community substantial convenience to uncover the genetic basis of epilepsy. PMID:25324312

Ran, Xia; Li, Jinchen; Shao, Qianzhi; Chen, Huiqian; Lin, Zhongdong; Sun, Zhong Sheng; Wu, Jinyu

2015-01-28

289

Investigation of the gene mutations in two Chinese families with X-linked infantile nystagmus  

PubMed Central

Purpose To identify the gene mutations causing X-linked infantile nystagmus in two Chinese families (NYS003 and NYS008), of which the NYS003 family was assigned to the FERM domain–containing 7 (FRMD7) gene linked region in our previous study, and no mutations were found by direct sequencing. Methods Two microsatellites, DXS1047 and DXS1001, were amplified using a PCR reaction for the linkage study in the NYS008 family. FRMD7 was sequenced and mutations were analyzed. Multiplex ligation-dependent probe amplification (MLPA) was used to detect FRMD7 mutations in the NYS003 family. Results The NYS008 family yielded a maximum logarithm of odds (LOD) score of 1.91 at ?=0 with DXS1001. FRMD7 sequencing showed a nucleotide change of c. 623A>G in exon7 of the patients’ FRMD7 gene, which was predicted to result in an H208R amino acid change. This novel mutation was absent in 100 normal Han Chinese controls. No FRMD7 gene mutations were detected by MLPA in the NYS003 family. Conclusions We identified a novel mutation, c. 623A>G (p. H208R), in a Han Chinese family with infantile nystagmus. This mutation expands the mutation spectrum of FRMD7 and contributes to the research on the molecular pathogenesis of FRMD7. PMID:21365021

Li, Ningdong; Wang, Xiaojuan; Wang, Yuchuan; Wang, Liming; Ying, Ming; Han, Ruifang; Liu, Yuyan

2011-01-01

290

Dominant mutations affecting muscle structure in Caenorhabditis elegans that map near the actin gene cluster.  

PubMed

By examining F1 progeny of mutagenized Caenorhabditis elegans larvae, we recovered several dominant mutations which affect muscle structure. Five of these new mutations resulted in phenotypes unlike the previously recognized unc-54 and unc-15 dominant alleles. Mapping studies placed all five mutations in the same small region of linkage group V. Polarized light, fluorescence and electron microscopic studies showed that a prominent feature of the disorganized myofilament lattice is the abnormal placement of thin filaments within the body wall muscle cells. Pharyngeal musculature is also affected by three of the mutations when homozygous. Of the five mutations only three are homozygous viable. All three of these have unusually high intragenic reversion rates either spontaneously (approximately 10(-6)) or after ethyl methanesulfonate mutagenesis (2 X 10(-5)), suggesting that reversion occurs through loss of function mutations. No unlinked suppressor mutations were found. The dominance of the mutations, the effect on thin filaments and the reversion properties suggested that these new dominant mutations lie in a gene or genes specifying a structural component of the thin filament. The positioning of a set of three actin sequences in the same region (Files et al., 1983) led us to speculate that these mutations lie in actin genes. PMID:6527380

Waterston, R H; Hirsh, D; Lane, T R

1984-12-15

291

VCP gene analyses in Japanese patients with sporadic amyotrophic lateral sclerosis identify a new mutation.  

PubMed

Accumulating evidence has proven that mutations in the VCP gene encoding valosin-containing protein (VCP) cause inclusion body myopathy with Paget disease of the bone and frontotemporal dementia. This gene was later found to be causative for amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, occurring typically in elderly persons. We thus sequenced the VCP gene in 75 Japanese patients with sporadic ALS negative for mutations in other genes causative for ALS and found a novel mutation, p.Arg487His, in 1 patient. The newly identified mutant as well as known mutants rendered neuronal cells susceptible to oxidative stress. The presence of the mutation in the Japanese population extends the geographic region for involvement of the VCP gene in sporadic ALS to East Asia. PMID:25457024

Hirano, Makito; Nakamura, Yusaku; Saigoh, Kazumasa; Sakamoto, Hikaru; Ueno, Shuichi; Isono, Chiharu; Mitsui, Yoshiyuki; Kusunoki, Susumu

2014-10-16

292

Two cases of Wiskott-Aldrich syndrome in neonates due to gene mutations.  

PubMed

Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive disease characterized by eczema, thrombocytopenia and immune deficiency. WAS gene mutations impair WAS protein function which cause WAS. The WAS-related disorders of X-linked thrombocytopenia (XLT) and X-linked congenital neutropenia (XLN) may have similar but less severe symptoms those are also caused by mutations of the same gene. We present two cases of WAS in neonates with WAS gene mutations. Early genetic diagnosis can help to the treatment and prevention this disease. PMID:23301916

Zhang, Shulian; Zhang, Rong; Chen, Chao; Sun, Jinqiao

2013-07-01

293

Software and database for the analysis of mutations in the human LDL receptor gene.  

PubMed Central

The low-density lipoprotein receptor (LDLr) plays a pivotal role in cholesterol homeostasis. Mutations in the LDLr gene (LDLR), which is located on chromosome 19, cause familial hypercholesterolemia (FH), an autosomal dominant disorder characterized by severe hypercholesterolemia associated with premature coronary atherosclerosis. To date almost 300 mutations have been identified in the LDLR gene. To facilitate the mutational analysis of the LDLR gene, and promote the analysis of the relationship between genotype and phenotype, a software package along with a computerized database (currently listing 210 entries) have been created. PMID:9016531

Varret, M; Rabès, J P; Collod-Béroud, G; Junien, C; Boileau, C; Béroud, C

1997-01-01

294

BMPR2 gene mutation in pulmonary arteriovenous malformation and pulmonary hypertension: a case report.  

PubMed

The transforming growth factor-? superfamily signaling pathway is thought to be involved in the pathogenesis of pulmonary arteriovenous malformation (PAVM). However, the association between bone morphogenetic protein receptor type 2 (BMPR2) gene mutations and PAVM remains unclear. We present a case of concurrent PAVM and pulmonary arterial hypertension (PAH), with a deletion mutation in exon 6 and exon 7 of the BMPR2 gene. Drug treatment for PAH improved the patient's hemodynamics and exercise capacity, but worsened oxygenation. This case suggests that BMPR2 gene mutation may be associated with the complex presentation of PAVM combined with PAH. PMID:24853021

Handa, Tomohiro; Okano, Yoshiaki; Nakanishi, Norifumi; Morisaki, Takayuki; Morisaki, Hiroko; Mishima, Michiaki

2014-05-01

295

Mutations in the Cystic Fibrosis Transmembrane Regulator Gene and In Vivo Transepithelial Potentials  

PubMed Central

Aim: To examine the relationship between cystic fibrosis transmembrane regulator gene mutations (CFTR) and in vivo transepithelial potentials. Methods: We prospectively evaluated 162 men including 31 healthy subjects, 21 obligate heterozygotes, 60 with congenital bilateral absence of the vas deferens (CBAVD) and 50 with CF by extensive CFTR genotyping, sweat chloride and nasal potential difference testing. Results: Six (10%) men with CBAVD carried no CFTR mutations, 18 (30%) carried one mutation, including the 5T variant, and 36 (60%) carried mutations on both alleles, for a significantly higher rate carrying one or more mutations than healthy controls (90% versus 19%, p < 0.001). There was an overlapping spectrum of ion channel measurements among the men with CBAVD, ranging from values in the control and obligate heterozygote range at one extreme, to values in the CF range at the other. All pancreatic-sufficient patients with CF and 34 of 36 patients with CBAVD with mutations on both alleles carried at least one mild mutation. However, the distribution of mild mutations in the two groups differed greatly. Genotyping, sweat chloride and nasal potential difference (alone or in combination) excluded CF in all CBAVD men with no mutations. CF was confirmed in 56% and 67% of CBAVD men carrying 1 and 2 CFTR mutations, respectively. Conclusion: Abnormalities of CFTR transepithelial function correlate with the number and severity of CFTR gene mutations. PMID:16840743

Wilschanski, Michael; Dupuis, Annie; Ellis, Lynda; Jarvi, Keith; Zielenski, Julian; Tullis, Elizabeth; Martin, Sheelagh; Corey, Mary; Tsui, Lap-Chee; Durie, Peter

2006-01-01

296

Clinical Significance of a Point Mutation in DNA Polymerase Beta (POLB) Gene in Gastric Cancer  

PubMed Central

Gastric cancer (GC) is a major cause of global cancer mortality. Genetic variations in DNA repair genes can modulate DNA repair capability and, consequently, have been associated with risk of developing cancer. We have previously identified a T to C point mutation at nucleotide 889 (T889C) in DNA polymerase beta (POLB) gene, a key enzyme involved in base excision repair in primary GCs. The purpose of this study was to evaluate the mutation and expression of POLB in a larger cohort and to identify possible prognostic roles of the POLB alterations in GC. Primary GC specimens and their matched normal adjacent tissues were collected at the time of surgery. DNA, RNA and protein samples were isolated from GC specimens and cell lines. Mutations were detected by PCR-RFLP/DHPLC and sequencing analysis. POLB gene expression was examined by RT-PCR, tissue microarray, Western blotting and immunofluorescence assays. The function of the mutation was evaluated by chemosensitivity, MTT, Transwell matrigel invasion and host cell reactivation assays. The T889C mutation was detected in 18 (10.17%) of 177 GC patients. And the T889C mutation was associated with POLB overexpression, lymph nodes metastases and poor tumor differentiation. In addition, patients with- the mutation had significantly shorter survival time than those without-, following postoperative chemotherapy. Furthermore, cell lines with T889C mutation in POLB gene were more resistant to the treatment of 5-fluorouracil, cisplatin and epirubicin than those with wild type POLB. Forced expression of POLB gene with T889C mutation resulted in enhanced cell proliferation, invasion and resistance to anticancer drugs, along with increased DNA repair capability. These results suggest that POLB gene with T889C mutation in surgically resected primary gastric tissues may be clinically useful for predicting responsiveness to chemotherapy in patients with GC. The POLB gene alteration may serve as a prognostic biomarker for GC.

Tan, Xiaohui; Wang, Hongyi; Luo, Guangbin; Ren, Shuyang; Li, Wenmei; Cui, Jiantao; Gill, Harindarpal S.; Fu, Sidney W.; Lu, Youyong

2015-01-01

297

Remarkable difference of somatic mutation patterns between oncogenes and tumor suppressor genes.  

PubMed

Cancers arise owing to mutations that confer selective growth advantages on the cells in a subset of tumor suppressor and/or oncogenes. To understand oncogenesis and diagnose cancers, it is crucial to discriminate these two groups of genes by using the difference in their mutation patterns. Here, we investigated>120,000 mutation samples in 66 well-known tumor suppressor genes and oncogenes of the COSMIC database, and found a set of significant differences in mutation patterns (e.g., non-3n-indel, non-sense SNP and mutation hotspot) between them. By screening the best measurement, we developed indices to readily distinguish one from another and predict clearly the unknown oncogenesis genes as tumor suppressors (e.g., ASXL1, HNF1A and KDM6A) or oncogenes (e.g., FOXL2, MYD88 and TSHR). Based on our results, a third gene group can be classified, which has a mutational pattern between tumor suppressors and oncogenes. The concept of the third gene group could help to understand gene function in different cancers or individual patients and to know the exact function of genes in oncogenesis. In conclusion, our study provides further insights into cancer-related genes and identifies several potential therapeutic targets. PMID:21887471

Liu, Haoxuan; Xing, Yuhang; Yang, Sihai; Tian, Dacheng

2011-12-01

298

Hybrid curation of gene–mutation relations combining automated extraction and crowdsourcing  

PubMed Central

Background: This article describes capture of biological information using a hybrid approach that combines natural language processing to extract biological entities and crowdsourcing with annotators recruited via Amazon Mechanical Turk to judge correctness of candidate biological relations. These techniques were applied to extract gene– mutation relations from biomedical abstracts with the goal of supporting production scale capture of gene–mutation–disease findings as an open source resource for personalized medicine. Results: The hybrid system could be configured to provide good performance for gene–mutation extraction (precision ?82%; recall ?70% against an expert-generated gold standard) at a cost of $0.76 per abstract. This demonstrates that crowd labor platforms such as Amazon Mechanical Turk can be used to recruit quality annotators, even in an application requiring subject matter expertise; aggregated Turker judgments for gene–mutation relations exceeded 90% accuracy. Over half of the precision errors were due to mismatches against the gold standard hidden from annotator view (e.g. incorrect EntrezGene identifier or incorrect mutation position extracted), or incomplete task instructions (e.g. the need to exclude nonhuman mutations). Conclusions: The hybrid curation model provides a readily scalable cost-effective approach to curation, particularly if coupled with expert human review to filter precision errors. We plan to generalize the framework and make it available as open source software. Database URL: http://www.mitre.org/publications/technical-papers/hybrid-curation-of-gene-mutation-relations-combining-automated PMID:25246425

Burger, John D.; Doughty, Emily; Khare, Ritu; Wei, Chih-Hsuan; Mishra, Rajashree; Aberdeen, John; Tresner-Kirsch, David; Wellner, Ben; Kann, Maricel G.; Lu, Zhiyong; Hirschman, Lynette

2014-01-01

299

Novel ABCC8 (SUR1) gene mutations in Asian Indian children with congenital hyperinsulinemic hypoglycemia.  

PubMed

Congenital hyperinsulinemic hypoglycemia (HI) is a heterogeneous genetic disorder of insulin secretion characterized by persistent hypoglycemia, most commonly associated with inactivating mutations of the ?-cell ATP-sensitive K(+) channel (K(ATP) channel) genes ABCC8 (encoding SUR1) and KCNJ11(encoding Kir6.2). This study aimed to screen the mutations in the genes associated with congenital HI in Asian Indian children. Recessive mutations of these genes cause hyperinsulinism that is unresponsive to treatment with channel agonists like diazoxide. Dominant K(ATP) mutations have been associated with diazoxide-responsive disease. The KCNJ11, ABCC8, GCK, HNF4A, and GLUD1 genes were analyzed by sequence analysis in 22 children with congenital HI. We found 10 novel mutations (c.1delA, c.61delG, c.267delT, c.619-629delCCCGAGGACCT, Gln444*, Leu724Pro, Ala847Thr, Trp898*, IVS30-2A>C, and Leu1454Arg) and two known mutations (Gly111Arg and Arg598*) in the ABCC8 gene. This study describes novel and known ABCC8 gene mutations in children with congenital HI. This is the first large genetic screening study on HI in India and our results will help clinicians in providing optimal treatment for patients with hyperinsulinemia and in assisting affected families with genetic counseling. PMID:25117148

Jahnavi, Suresh; Poovazhagi, Varadarajan; Kanthimathi, Sekar; Balamurugan, Kandasamy; Bodhini, Dhanasekaran; Yadav, Jaivinder; Jain, Vandana; Khadgawat, Rajesh; Sikdar, Mahuya; Bhavatharini, Ayurchelvan; Das, Ashok Kumar; Kaur, Tanvir; Mohan, Viswanathan; Radha, Venkatesan

2014-09-01

300

DNA repair genes are selectively mutated in diffuse large B cell lymphomas  

PubMed Central

DNA repair mechanisms are fundamental for B cell development, which relies on the somatic diversification of the immunoglobulin genes by V(D)J recombination, somatic hypermutation, and class switch recombination. Their failure is postulated to promote genomic instability and malignant transformation in B cells. By performing targeted sequencing of 73 key DNA repair genes in 29 B cell lymphoma samples, somatic and germline mutations were identified in various DNA repair pathways, mainly in diffuse large B cell lymphomas (DLBCLs). Mutations in mismatch repair genes (EXO1, MSH2, and MSH6) were associated with microsatellite instability, increased number of somatic insertions/deletions, and altered mutation signatures in tumors. Somatic mutations in nonhomologous end-joining (NHEJ) genes (DCLRE1C/ARTEMIS, PRKDC/DNA-PKcs, XRCC5/KU80, and XRCC6/KU70) were identified in four DLBCL tumors and cytogenetic analyses revealed that translocations involving the immunoglobulin-heavy chain locus occurred exclusively in NHEJ-mutated samples. The novel mutation targets, CHEK2 and PARP1, were further screened in expanded DLBCL cohorts, and somatic as well as novel and rare germline mutations were identified in 8 and 5% of analyzed tumors, respectively. By correlating defects in a subset of DNA damage response and repair genes with genomic instability events in tumors, we propose that these genes play a role in DLBCL lymphomagenesis. PMID:23960188

de Miranda, Noel FCC; Peng, Roujun; Georgiou, Konstantinos; Wu, Chenglin; Sörqvist, Elin Falk; Berglund, Mattias; Chen, Longyun; Gao, Zhibo; Lagerstedt, Kristina; Lisboa, Susana; Roos, Fredrik; van Wezel, Tom; Teixeira, Manuel R.; Rosenquist, Richard; Sundström, Christer; Enblad, Gunilla; Nilsson, Mats; Zeng, Yixin; Kipling, David

2013-01-01

301

Campomelic dysplasia and autosomal sex reversal caused by mutations in an SRY-related gene  

Microsoft Academic Search

Induction of testis development in mammals requires the presence of the Y-chromosome gene SPY. This gene must exert its effect by interacting with other genes in the sex-determination pathway. Cloning of a translocation chromosome breakpoint from a sex-reversed patient with campomelic dysplasia, followed by mutation analysis of an adjacent gene, indicates that SOX9, an SRY-related gene, is involved in both

Jamie W. Foster; Marina A. Dominguez-Steglich; Silvana Guioli; Cheni Kwok; Polly A. Weller; Milena Stevanovic; Jean Weissenbach; Sahar Mansour; Ian D. Young; Peter N. Goodfellow; J. David Brook; Alan J. Schafer

1994-01-01

302

A Japanese case with Frasier syndrome caused by the splice junction mutation of WT1 gene.  

PubMed

The Wilms' tumor suppressor gene, WT1, plays an important role in the development of the urogenital system and also subsequent normal function of this system. Recently, the splice mutations in intron 9 of WT1 gene have been detected in Frasier syndrome, which is characterized by streak gonads, pseudohermaphroditism, slowly progressive nephropathy and frequent development of gonadoblastoma. Here to elucidate the molecular basis in a Japanese patient of Frasier syndrome, WT1 gene was analyzed by polymerase-chain-reaction (PCR) and direct sequencing. We identified the splice junction mutation in intron 9 of WT1, which is recognized as a mutation hot-spot in intron 9. This finding concludes that 1) the mutation in intron 9 might be the cause of Frasier syndrome, and 2) the mutation hot-spot in Japanese and Caucasian patients is similar. PMID:10670748

Okuhara, K; Tajima, S; Nakae, J; Sasaki, S; Tochimaru, H; Abe, S; Fujieda, K

1999-10-01

303

[Identification of mutation and polymorphic changes in the CFTR gene of patients with obstructive azoospermia].  

PubMed

Obstructive azoospermia is one of the symptoms of congenital bilateral absence of the vas deferens (CBAVD)--disease which is suggested as primarily genital form of cystic fibrosis. CBAVD is a result of mutations and polymorphisms in CFTR gene. We studied 9 the most common mutations and identified 3 mutations (delta F508, R117H, G542X). The study showed that: 37.1% of CBAVD patients (13 out of 35 examined patients) carried mutations in a single or both copies of the gene. We also found the increased frequency of IVS8-5T allele in this group. No increased frequency of mutations in CFTR gene was found in group of men with incorrect spermatogenesis. PMID:11247407

Sobczy?ska-Tomaszewska, A; Wolski, J K; Bal, J

2000-01-01

304

Mutations of the CYP1B1 gene in congenital anterior staphylomas  

PubMed Central

Purpose Here, we present two patients with congenital anterior staphyloma, with mutations in the CYP1B1 gene. Methods We reviewed the medical records, including the genetic analysis. Results Two unrelated patients presented with congenital anterior staphylomas. Both patients showed mutations in the CYP1B1 gene. The first patient, the product of a consanguineous marriage, showed a homozygous misssense mutation g.3987G>A (p.G61E). The second patient had compound heterozygous misssense mutations [g.4160 G>T (p.A119S) and g.8131 C>G (p.L432V)]. Conclusion CYP1B1 gene mutation may be associated with congenital anterior staphylomas. PMID:24591815

Al Judaibi, Ramzi; Abu-Amero, Khaled K; Morales, Jose; Al Shahwan, Sami; Edward, Deepak P

2014-01-01

305

Identification of a novel mutation of the CPO gene in a Japanese hereditary coproporphyria family.  

PubMed

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase (CPO) caused by a mutation in the CPO gene. Only 11 mutations of the gene have been reported in HCP patients. We report another mutation in a Japanese family. Polymerase chain reaction-single strand conformational polymorphism and direct sequence analyses demonstrated a C to T substitution in exon 1 of the CPO gene at nucleotide position 85, which lies in the putative presequence for targeting to mitochondria. This mutation changes the codon for glutamine to a termination codon at amino acid position 29. MaeI restriction analysis showed two other carriers in the family. The C-T mutation is located within a recently proposed putative alternative translation initiation codon (TIC-1), supporting that TIC-1 is the real TIC rather than TIC-2. PMID:9843038

Susa, S; Daimon, M; Kondo, H; Kondo, M; Yamatani, K; Sasaki, H

1998-11-16

306

Mutation analysis of the G4.5 gene in patients with isolated left ventricular noncompaction  

Microsoft Academic Search

Mutations in the gene G4.5, originally associated with Barth syndrome, have been reported to result in a wide spectrum of severe infantile X-linked cardiomyopathies. The purpose of this study was to investigate patients with isolated left ventricular noncompaction (LVNC) for disease-causing mutations in G4.5. In 27 patients including 10 families with isolated LVNC, mutation analysis of G4.5 was performed using

Rui Chen; Tohru Tsuji; Fukiko Ichida; Karla R Bowles; Xianyi Yu; Sayaka Watanabe; Keiichi Hirono; Shinichi Tsubata; Yuji Hamamichi; Jun Ohta; Yasuharu Imai; Neil E Bowles; Toshio Miyawaki; Jeffrey A Towbin

2002-01-01

307

A Differential Wiring Analysis of Expression Data Correctly Identifies the Gene Containing the Causal Mutation  

Microsoft Academic Search

Transcription factor (TF) regulation is often post-translational. TF modifications such as reversible phosphorylation and missense mutations, which can act independent of TF expression level, are overlooked by differential expression analysis. Using bovine Piedmontese myostatin mutants as proof-of-concept, we propose a new algorithm that correctly identifies the gene containing the causal mutation from microarray data alone. The myostatin mutation releases the

Nicholas J. Hudson; Antonio Reverter; Brian P. Dalrymple

2009-01-01

308

Two mismatch repair gene mutations found in a colon cancer patient - which one is pathogenic?  

Microsoft Academic Search

Hereditary nonpolyposis colorectal cancer (HNPCC) is a dominantly inherited cancer syndrome. Germline mutations in five different mismatch repair (MMR) genes, MSH2, MSH6, MLH1, MLH3, and PMS2 are linked to HNPCC. Here, we describe two colon cancer families in which the index patients carry missense mutations in both MSH2 and MSH6. The MSH2 mutation, I145M, is the same in both families,

Reetta Kariola; Robyn Otway; Karin E. Lönnqvist; Tiina E. Raevaara; Finlay Macrae; Yvonne J. Vos; Maija Kohonen-Corish; Robert M. Hofstra; Minna Nyström-Lahti

2003-01-01

309

Mutational analysis of the NPHP4 gene in 250 patients with nephronophthisis.  

PubMed

Nephronophthisis (NPH), a recessive cystic kidney disease, is the most frequent genetic cause for end-stage renal disease in the first two decades of life. Mutations in three genes (NPHP1, 2, and 3) were identified as causative. Extrarenal manifestations are known, such as retinitis pigmentosa (Senior-Loken syndrome, SLS) and ocular motor apraxia type Cogan. Recently, we identified a novel gene (NPHP4) as mutated in NPH. To date, a total of only 13 different NPHP4 mutations have been described. To determine the frequency of NPHP4 mutations, we performed mutational analysis by direct sequencing of all 30 NPHP4 exons in 250 different patients with isolated NPH, SLS, or Cogan syndrome ascertained worldwide over 14 years. We identified 23 novel NPHP4 sequence variants in 26/250 different patients (10%). Interestingly, we detected homozygous or compound heterozygous mutations of NPHP4 in only 6/250 different patients (2.4%), but only one heterozygous NPHP4 sequence variant in 20/250 different patients (8%). In the six patients with two NPHP4 mutations, 5/8 mutations (63%) were likely loss-of-function mutations, whereas in the 20 patients with only one sequence variant, only 1/20 (5%) was a likely loss-of-function (i.e., truncating) mutation. We conclude that: i) two recessive mutations in NPHP4 are a rare cause of nephronophthisis; ii) single heterozygous NPHP4 sequence variants are three times more prevalent than two recessive mutations; iii) there is no genotype/phenotype correlation; iv) there must exist further genes causing nephronophthisis, since in 224/250 (90%) patients, no sequence variants in either of the four NPH genes were detected. PMID:15776426

Hoefele, Julia; Sudbrak, Ralf; Reinhardt, Richard; Lehrack, Silvia; Hennig, Steffen; Imm, Anita; Muerb, Ulla; Utsch, Boris; Attanasio, Massimo; O'Toole, John F; Otto, Edgar; Hildebrandt, Friedhelm

2005-04-01

310

Characterization of phenylalanine hydroxylase gene mutations in phenylketonuria in Xinjiang of China.  

PubMed

To investigate the spectrum and frequency of phenylalanine hydroxylase (PAH) gene mutations in phenylketonuria (PKU) patients in Xinjiang, China. Polymerase chain reaction (PCR), in combination with single-strand conformation polymorphism (SSCP) and DNA sequencing analyses were performed, to screen potential mutations in the PAH gene in 46 individual PKU patients. Direct DNA sequencing was used to analyze the all of the exons in the PAH gene, including the promoter and flanking intron regions, in another 15 PKU patients. Our results indicated that, 30 different mutation types were identified in all 122 PAH alleles, with the mutation detection rate of 78.7% (96/122). Four novel mutations, i.e., 5'-Flanking -626G>A, 5'-Flanking -480DelACT, S196fsX4, and IVS8+1G>C, were identified for the first time. Similar to other regions in North China, R243Q, EX6-96A>G, IVS4-1A>G, R111X, and Y356X were the most prevalent PAH mutations in PKU patients from Xinjiang. Additionally, common mutations showed different frequencies in Xinjiang, when compared to other areas. Furthermore, sixteen different PAH gene mutation types were identified for the first time in the minorities in Xinjiang. Distinctive mutation spectrum of PAH gene in PKU patients from Xinjiang were characterized, which may promote the construction of PAH gene mutation database and serve as valuable tools for genetic diagnosis and counseling, and prognostic evaluation for PKU cases in the local area. PMID:25550961

Yu, Wuzhong; He, Jiang; Yang, Xi; Zou, Hongyun; Gui, Junhao; Wang, Rui; Yang, Liu; Wang, Zheng; Lei, Quan

2014-01-01

311

Characterization of phenylalanine hydroxylase gene mutations in phenylketonuria in Xinjiang of China  

PubMed Central

To investigate the spectrum and frequency of phenylalanine hydroxylase (PAH) gene mutations in phenylketonuria (PKU) patients in Xinjiang, China. Polymerase chain reaction (PCR), in combination with single-strand conformation polymorphism (SSCP) and DNA sequencing analyses were performed, to screen potential mutations in the PAH gene in 46 individual PKU patients. Direct DNA sequencing was used to analyze the all of the exons in the PAH gene, including the promoter and flanking intron regions, in another 15 PKU patients. Our results indicated that, 30 different mutation types were identified in all 122 PAH alleles, with the mutation detection rate of 78.7% (96/122). Four novel mutations, i.e., 5’-Flanking -626G>A, 5’-Flanking -480DelACT, S196fsX4, and IVS8+1G>C, were identified for the first time. Similar to other regions in North China, R243Q, EX6-96A>G, IVS4-1A>G, R111X, and Y356X were the most prevalent PAH mutations in PKU patients from Xinjiang. Additionally, common mutations showed different frequencies in Xinjiang, when compared to other areas. Furthermore, sixteen different PAH gene mutation types were identified for the first time in the minorities in Xinjiang. Distinctive mutation spectrum of PAH gene in PKU patients from Xinjiang were characterized, which may promote the construction of PAH gene mutation database and serve as valuable tools for genetic diagnosis and counseling, and prognostic evaluation for PKU cases in the local area.

Yu, Wuzhong; He, Jiang; Yang, Xi; Zou, Hongyun; Gui, Junhao; Wang, Rui; Yang, Liu; Wang, Zheng; Lei, Quan

2014-01-01

312

Mutations in planar cell polarity gene SCRIB are associated with spina bifida.  

PubMed

Neural tube defects (NTDs) (OMIM #182940) including anencephaly, spina bifida and craniorachischisis, are severe congenital malformations that affect 0.5-1 in 1,000 live births in the United States, with varying prevalence around the world. Mutations in planar cell polarity (PCP) genes are believed to cause a variety of NTDs in both mice and humans. SCRIB is a PCP-associated gene. Mice that are homozygous for the Scrib p.I285K and circletail (Crc) mutations, present with the most severe form of NTDs, namely craniorachischisis. A recent study reported that mutations in SCRIB were associated with craniorachischisis in humans, but whether SCRIB mutations contribute to increased spina bifida risk is still unknown. We sequenced the SCRIB gene in 192 infants with spina bifida and 190 healthy controls. Among the spina bifida patients, we identified five novel missense mutations that were predicted-to-be-deleterious by the PolyPhen software. Of these five mutations, three of them (p.P1043L, p.P1332L, p.L1520R) significantly affected the subcellular localization of SCRIB. In addition, we demonstrated that the craniorachischisis mouse line-90 mutation I285K, also affected SCRIB subcellular localization. In contrast, only one novel missense mutation (p.A1257T) was detected in control samples, and it was predicted to be benign. This study demonstrated that rare deleterious mutations of SCRIB may contribute to the multifactorial risk for human spina bifida. PMID:23922697

Lei, Yunping; Zhu, Huiping; Duhon, Cody; Yang, Wei; Ross, M Elizabeth; Shaw, Gary M; Finnell, Richard H

2013-01-01

313

Relation of Gene Expression Phenotype to Immunoglobulin Mutation Genotype in B Cell Chronic Lymphocytic Leukemia  

Microsoft Academic Search

The most common human leukemia is B cell chronic lymphocytic leukemia (CLL), a malig- nancy of mature B cells with a characteristic clinical presentation but a variable clinical course. The rearranged immunoglobulin (Ig) genes of CLL cells may be either germ-line in sequence or somatically mutated. Lack of Ig mutations defined a distinctly worse prognostic group of CLL patients raising

Andreas Rosenwald; Ash A. Alizadeh; George Widhopf; Richard Simon; R. Eric Davis; Xin Yu; Liming Yang; Oxana K. Pickeral; Laura Z. Rassenti; John Powell; David Botstein; John C. Byrd; Michael R. Grever; Bruce D. Cheson; Nicholas Chiorazzi; Wyndham H. Wilson; Thomas J. Kipps; Patrick O. Brown; Louis M. Staudt

2001-01-01

314

A mutation in CTSK gene in an autosomal recessive pycnodysostosis family of Pakistani origin  

Microsoft Academic Search

BACKGROUND: Pycnodysostosis is a rare autosomal recessive skeletal dysplasia characterized by short stature, osteosclerosis, acro-osteolysis, frequent fractures and skull deformities. Mutations in the gene encoding cathepsin K (CTSK), a lysosomal cysteine protease, have been found to be responsible for this disease. OBJECTIVES: To identify pathogenic mutation in a consanguineous Pakistani family with 3 affected individuals demonstrating autosomal recessive pycnodysostosis. METHODS:

Muhammad Naeem; Sabeen Sheikh; Wasim Ahmad

2009-01-01

315

Mutational hot spot in the p53 gene in human hepatocellular carcinomas  

Microsoft Academic Search

HUMAN hepatocellular carcinomas (HCC) from patients in Qidong, an area of high incidence in China, in which both hepatitis B virus and aflatoxin B1 are risk factors1, were analysed for mutations in p53, a putative tumour-suppressor gene. Eight of the 16 HCC had a point mutation at the third base position of codon 249. The G --> T transversion in

I. C. Hsu; R. A. Metcalf; T. Sun; J. A. Welsh; N. J. Wang; C. C. Harris

1991-01-01

316

Osteogenesis imperfecta without features of type V caused by a mutation in the IFITM5 gene  

PubMed Central

Osteogenesis imperfecta (OI) is typically caused by mutations in type 1 collagen genes, but in recent years new recessive and dominant forms caused by mutations in a plethora of different genes have been characterized. OI type V is a dominant form caused by the recurrent (c.-14C>T) mutation in the 5?UTR of the IFITM5 gene. The mutation adds 5 residues to the N-terminus of the IFITM5 but the pathophysiology of the disease still remains to be elucidated. Typical clinical features present in the majority of OI type V patients include interosseous membrane calcification between the radius and ulna, and the tibia and fibula, radial head dislocation and significant hyperplastic callus formation at the site of fractures. We report a 5 year-old child with clinical features of OI type III or severe OI type IV (characteristic facies, grey sclerae, typical fractures) and absence of classical features of OI type V with a de novo recurrent IFITM5 mutation (c.-14C>T), now typical of OI type V. This highlights the variability of OI caused by IFITM5 mutations and suggests screening for mutations in this gene in most cases of OI where type 1 collagen mutations are absent. PMID:23674381

Grover, Monica; Campeau, Philippe M.; Lietman, Caressa Dee; Lu, James T.; Gibbs, Richard A.; Schlesinger, Alan E.; Lee, Brendan H.

2013-01-01

317

p53 gene mutations in rectal cancer associated with schistosomiasis japonica in Chinese patients  

Microsoft Academic Search

Mutations in p53 tumor suppressor gene were examined in 44 Chinese patients with rectal cancer, including 22 cases with advanced schistosomiasis japonica and 22 cases without schistosomiasis. In schistosomal rectal cancer (SRC), 13 mutations were found in 10 cases, which included 11 base-pair substitutions and two deletions. Of 11 base substitutions, nine were transitions and two were transversions and seven

Renli Zhang; Satoru Takahashi; Shin-ichiro Orita; Ayako Yoshida; Haruhiko Maruyama; Tomoyuki Shirai; Nobuo Ohta

1998-01-01

318

Mutation frequencies of Xlinked mental retardation genes in families from the EuroMRX consortium.  

E-print Network

Mutation frequencies of Xlinked mental retardation genes in families from the EuroMRX consortium Xlinked mental retardation (XLMR). After exclusion of Fragile X (Fra X) syndrome, probands from carriers, the mental retardation phenotype could be explained by a mutation. There was no difference

Institut des Sciences Cognitives, CNRS

319

Mutation patterns of 16 genes in primary and secondary acute myeloid leukemia (AML) with normal cytogenetics.  

PubMed

Acute myeloid leukemia patients with normal cytogenetics (CN-AML) account for almost half of AML cases. We aimed to study the frequency and relationship of a wide range of genes previously reported as mutated in AML (ASXL1, NPM1, FLT3, TET2, IDH1/2, RUNX1, DNMT3A, NRAS, JAK2, WT1, CBL, SF3B1, TP53, KRAS and MPL) in a series of 84 CN-AML cases. The most frequently mutated genes in primary cases were NPM1 (60.8%) and FLT3 (50.0%), and in secondary cases ASXL1 (48.5%) and TET2 (30.3%). We showed that 85% of CN-AML patients have mutations in at least one of ASXL1, NPM1, FLT3, TET2, IDH1/2 and/or RUNX1. Serial samples from 19 MDS/CMML cases that progressed to AML were analyzed for ASXL1/TET2/IDH1/2 mutations; seventeen cases presented mutations of at least one of these genes. However, there was no consistent pattern in mutation acquisition during disease progression. This report concerns the analysis of the largest number of gene mutations in CN-AML studied to date, and provides insight into the mutational profile of CN-AML. PMID:22912701

Fernandez-Mercado, Marta; Yip, Bon Ham; Pellagatti, Andrea; Davies, Carwyn; Larrayoz, María José; Kondo, Toshinori; Pérez, Cristina; Killick, Sally; McDonald, Emma-Jane; Odero, María Dolores; Agirre, Xabier; Prósper, Felipe; Calasanz, María José; Wainscoat, James S; Boultwood, Jacqueline

2012-01-01

320

Buxbaum et al. 1 Mutation screening of the PTEN gene in patients with autism spectrum  

E-print Network

Buxbaum et al. 1 Mutation screening of the PTEN gene in patients with autism spectrum disorders, New York, USA 2 Department of Psychiatry and Seaver Autism Research Center, Mount Sinai School: PTEN mutation screening in autism HALauthormanuscriptinserm-00125293,version1 HAL author manuscript

321

RESEARCH ARTICLE Open Access Germline mutation in the RAD51B gene confers  

E-print Network

, and BRIP1 and PALB2, associated with a moderate risk [7-9]. While breast cancer predisposition is conferred by mono-allelic germline mutations in these genes, bi-allelic germline mutations in BRCA2, BRIP1 and PALB2

Paris-Sud XI, Université de

322

Interactions between cut wing mutations and mutations in zeste , and the enhancer of yellow and Polycomb group genes of Drosophila melanogaster  

Microsoft Academic Search

The phenotypic expression of several mutations in thecut locus ofDrosophila melanogaster is modified by mutations in thezeste, e(y)2 ande(y)3 genes and in some genes of thePolycomb group. All tested sensitivecut mutations have a partially inactivated cut wing enhancer.e(y)3ul, zv77h andSu(z)25 mutations enhance, whilee(y)2ul, zOp6, Psc1, Su(z)301, Su(z)302 andScmD1 mutations suppress the ct mutant phenotype. The results are discussed in terms

L. Melnikova; A. Kulikov; P. Georgiev

1996-01-01

323

Quantification of the paternal allele bias for new germline mutations in the retinoblastoma gene  

SciTech Connect

New germline mutations in the human retinoblastoma gene preferentially arise on a paternally derived allele. In nonhereditary retinoblastoma, the initial somatic mutation seems to have no such bias. The few previous reports of these phenomena included relatively few cases (less than a dozen new germline or initial somatic mutations), so that the magnitude of the paternal allele bias for new germline mutations is not known. Knowledge of the magnitude of the bias is valuable for genetic counseling, since, for example, patients with new germline mutations who reproduce transmit risk for retinoblastoma according to the risk that the transmitted allele has a germline mutation. We sought to quantitate the paternal allele bias and to determine whether paternal age is a factor possibly accounting for it. We studied 311 families with retinoblastoma (261 simplex, 50 multiplex) that underwent clinical genetic testing and 5 informative families recruited from earlier research. Using RFLPs and polymorphic microsatellites in the retinoblastoma gene, we could determine the parental origin of 45 new germline mutations and 44 probable initial somatic mutations. Thirty-seven of the 45 new germline mutations, or 82%, arose on a paternal allele while only 24 of the 44 initial somatic mutations (55%) did so. Increased paternal age does not appear to account for the excess of new paternal germline mutations, since the average age of fathers of children with new germline mutations (29.4 years, n=26, incomplete records on 11) was not significantly different from the average age of fathers of children with maternal germline mutations or somatic initial mutations (29.8 years, n=35, incomplete records on 17).

Morrow, J.F.; Rapaport, J.M.; Dryia, T.P. [Massachusetts Eye & Ear Infirmary, Boston, MA (United States)

1994-09-01

324

Identification of novel mutations in the KCNQ4 gene of patients with nonsyndromic deafness from Taiwan.  

PubMed

Ion channels play important roles in signal transduction and in the regulation of the ionic composition of intra- and extracellular fluids. Mutations in ion channels have long been thought to be responsible for some forms of hearing loss. Defects in KCNQ4, a voltage-gated potassium channel, are a cause of nonsyndromic sensorineural deafness type 2, an autosomal dominant form of progressive hearing loss. We present data of mutation analysis of KCNQ4 from 185 unrelated Taiwanese probands with nonsyndromic hearing loss. The analysis revealed three novel KCNQ4 mutations and many polymorphisms. The prevalence of KCNQ4 gene mutations in this study was 1.62% (3/185). The mutations include a missense mutation (F182L) and two silent mutations (R216R and T501T). The F182L missense mutation was located in the S3 domain of KCNQ4. The F182 residue of KCNQ4 is highly conserved in KCNQ4 among various species and is less conserved in all members of the KCNQ family. In addition, although R216R is a silent mutation and does not alter the content of amino acid residue, the neural network prediction system revealed that it can potentially create a novel splice donor site during transcription. This mutation might affect the protein structure of KCNQ4 and consequently the normal function of the K+ channel. Our data provide the first comprehensive analysis of the KCNQ4 gene in Taiwanese patients with nonsyndromic deafness. PMID:17033161

Su, Ching-Chyuan; Yang, Jiann-Jou; Shieh, Jia-Ching; Su, Mao-Chang; Li, Shuan-Yow

2007-01-01

325

UCSD scientists find gene mutation for aggressive form of pancreatic cancer  

Cancer.gov

Researchers at the University of California, San Diego School of Medicine have identified a mutated gene common to adenosquamous carcinoma tumors – the first known unique molecular signature for this rare, but particularly virulent, form of pancreatic cancer.

326

A novel mutation of coproporphyrinogen oxidase (CPO) gene in a Japanese family.  

PubMed

Hereditary coproporphyria (HCP) is an autosomal dominant disease characterized by a deficiency of coproporphyrinogen oxidase (CPO). Only 11 mutations of the gene have been reported to date as the mutations responsible for HCP. We report here a novel mutation of the gene responsible for the disease in a Japanese family. Analysis of the polymerase chain reaction (PCR) amplified DNA fragments of the gene by direct-sequencing and/or cloning-based sequencing methods revealed the gene abnormality responsible for the disease. The mutation found was a single base deletion of T at nt position 526, which results in frame shift and truncation of coded protein at amino acid position 204. Screening of pre-symptomatic cases seemed to be possible by PCR restriction analysis using restriction enzyme Xcm I. PMID:9747031

Susa, S; Daimon, M; Yamamori, I; Kondo, M; Yamatani, K; Sasaki, H; Kato, T

1998-01-01

327

1/9/09 2:14 PMResearchers Pinpoint Spontaneous Gene Mutations Responsible for 10 Percent of Non-Familial Cases of Schizophrenia Page 1 of 3http://cumc.columbia.edu/news/press_releases/gene-mutation-schizophrenia.html  

E-print Network

-Familial Cases of Schizophrenia Page 1 of 3http://cumc.columbia.edu/news/press_releases/gene-mutation-schizophrenia Gene Mutations Responsible for 10 Percent of Non-Familial Cases of Schizophrenia NEW YORK (May 30, 2008) ­ Scans of the genome of patients with schizophrenia have revealed rare spontaneous copy number mutations

328

The Mutator Gene Swi8 Effects Specific Mutations in the Mating-Type Region of Schizosaccharomyces Pombe  

PubMed Central

The swi8(+) gene of Schizosaccharomyces pombe appears to be involved in the termination step of copy synthesis during mating-type (MT) switching. Mutations in swi8 confer a general mutator phenotype and, in particular, generate specific mutations in the MT region. Sequencing of the MT cassettes of the h(90) swi8-137 mutant revealed three altered sites. One is situated at the switching (smt) signal adjacent to the H1 homology box of the expression locus mat1:1. It reduces the rate of MT switching. The alteration at the smt signal arose frequently in other h(90) swi8 strains and is probably caused by gene conversion in which the sequence adjacent to the H1 box of mat2:2 is used as template. This change might be generated during the process of MT switching when hybrid DNA formation is anomalously extended into the more heterologous region flanking the H1 homology box. In addition to the gene conversion at mat1:1, two mutations were found in the H3 homology boxes of the silent cassettes mat2:2 and mat3:3. PMID:7851760

Fleck, O.; Rudolph, C.; Albrecht, A.; Lorentz, A.; Schar, P.; Schmidt, H.

1994-01-01

329

Novel mutations in the TBX5 gene in patients with Holt-Oram Syndrome  

PubMed Central

The Holt-Oram syndrome (HOS) is an autosomal dominant condition characterized by upper limb and cardiac malformations. Mutations in the TBX5 gene cause HOS and have also been associated with isolated heart and arm defects. Interactions between the TBX5, GATA4 and NKX2.5 proteins have been reported in humans. We screened the TBX5, GATA4, and NKX2.5 genes for mutations, by direct sequencing, in 32 unrelated patients presenting classical (8) or atypical HOS (1), isolated congenital heart defects (16) or isolated upper-limb malformations (7). Pathogenic mutations in the TBX5 gene were found in four HOS patients, including two new mutations (c.374delG; c.678G > T) in typical patients, and the hotspot mutation c.835C > T in two patients, one of them with an atypical HOS phenotype involving lower-limb malformations. Two new mutations in the GATA4 gene were found in association with isolated upper-limb malformations, but their clinical significance remains to be established. A previously described possibly pathogenic mutation in the NKX2.5 gene (c.73C > 7) was detected in a patient with isolated heart malformations and also in his clinically normal father. PMID:21637475

2010-01-01

330

Novel Gene Mutations in Patients With Left Ventricular Noncompaction or Barth Syndrome  

Microsoft Academic Search

Background—Mutations in the gene G4.5 result in a wide spectrum of severe infantile cardiomyopathic phenotypes, including isolated left ventricular noncompaction (LVNC), as well as Barth syndrome (BTHS) with dilated cardiomyopathy (DCM). The purpose of this study was to investigate patients with LVNC or BTHS for mutations in G4.5 or other novel genes. Methods and Results—DNA was isolated from 2 families

Fukiko Ichida; Shinichi Tsubata; Karla R. Bowles; Noriyuki Haneda; Keiichiro Uese; Toshio Miyawaki; W. Jeffrey Dreyer; John Messina; Hua Li; Neil E. Bowles; Jeffrey A. Towbin

2010-01-01

331

ISOLATION AND CHARACTERIZATION OF MUTATIONS IN THE @TUBULIN GENE OF SACCHAROMYCES CEREVISIAE  

Microsoft Academic Search

Of 173 mutants of Saccharomyces cerevisiae resistant to the antimitotic drug benomyl (BenR), six also conferred cold-sensitivity for growth and three others conferred temperature-sensitivity for growth in the absence of benomyl. All of the benR mutations tested, including the nine conditional-lethal mutations, were shown to be in the same gene. This gene, TUBP, has previously been molecu- larly cloned and

JAMES H. THOMAS; NORMA F. NEFF; DAVID BOTSTEIN

332

Mutations of the p53 Tumor Suppressor Gene Occur Infrequently in Wilms' Tumor  

Microsoft Academic Search

Mutations of the p53 tumor suppressor gene occur frequently in a variety ofadult-onset tumors, including colon, breast, lung, and brain, yet are infrequently identified In pediatric malignancies. Wilma' tumor, a common solid tumor ofchildhood, can be associated with mutations of the w'ri gene.Alterations of thep53genehavebeenshownto modulate the ability of WT1to transactivate its targets. Although positive p5.3 immu nostaining has been

David Malkin; Elizabeth Sexsmith; Herman Yeger; G. Williams; Max J. Coppes

333

A Novel Activating Mutation of the K- ras Gene in Human Primary Colon Adenocarcinoma  

Microsoft Academic Search

We identified a novel type of point mutation at the 22nd codon of the K-ras gene in a primary colon cancer. The mutation was C to A transversion substituting lysine (AAG) for normal glutamine (CAG) codon. Biological activity of this mutant K-ras gene was tested by expression of full-length cDNA clones in NIH3T3 cells. Most of the K-ras Lys22-transfected cells

Kazunori Tsukuda; Motohiko Tanino; Hiroyuki Soga; Nobuyoshi Shimizu; Kenji Shimizu

2000-01-01

334

Mutation to Herbicide Resistance Maps within the psbA Gene of Anacystis nidulans R2  

Microsoft Academic Search

A psbA gene encoding the target of photosystem II herbicide inhibition the 32,000-dalton thylakoid membrane protein, has cloned from a mutant of Anacystis nidulans R2, Which is resistant to 3-(3,4-dicholorophenyl)-1,1-dimethylurea-(diuron). A cloned DNA fragnebt from within the coding region of this gene transforms wild-type cells to herbicide resistance, proving that mutation within psbA is responsible for that phenotype. The mutation

Susan S. Golden; Robert Haselkorn

1985-01-01

335

Novel stop and frameshifting mutations in the autosomal dominant polycystic kidney disease 2 (PKD2) gene  

Microsoft Academic Search

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most frequent inherited disorders. The majority of cases\\u000a are due to mutation of the PKD1 gene, on 16p13.3, while in most of the remainder the disease maps to the PKD2 locus, at chromosome\\u000a 4q21-q23. Recently, the PKD2 gene has been positionally cloned and three nonsense mutations within the coding sequence

Miguel Viribay; Tomohito Hayashi; Dolores Tellería; Toshio Mochizuki; David M. Reynolds; Rafael Alonso; Xose M. Lens; Felipe Moreno; Peter C. Harris; Stefan Somlo; José L. San Millán

1997-01-01

336

Fanconi Anemia Gene Mutations Are Not Involved in Sporadic Wilms Tumor  

Microsoft Academic Search

Bi-allelic germline mutations of the Fancom anemia (FA) genes, PALB2\\/FANCN and BRCA2\\/FANCD1, have been reported in a few Wilms tumor (WT) patients with an atypical FA phenotype Therefore, we screened a random cohort of 47 Dutch WT cases for germline mutations in these two FA-genes by DNA sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA) Although several cases appeared to carry

Muriel A. Adank; Heidi Segers; Mil van S. E; Helsdingen van Y. M; Najim Ameziane; Ouweland van den A. M. W; Anja Wagner; Hanne Meijers-Heijboer; Marcel Kool; Jan de Kraker; Quinten Waisfisz; Marry M. van den Heuvel-Eibrink

2010-01-01

337

Whole exome sequencing reveals concomitant mutations of multiple FA genes in individual Fanconi anemia patients  

PubMed Central

Background Fanconi anemia (FA) is a rare inherited genetic syndrome with highly variable clinical manifestations. Fifteen genetic subtypes of FA have been identified. Traditional complementation tests for grouping studies have been used generally in FA patients and in stepwise methods to identify the FA type, which can result in incomplete genetic information from FA patients. Methods We diagnosed five pediatric patients with FA based on clinical manifestations, and we performed exome sequencing of peripheral blood specimens from these patients and their family members. The related sequencing data were then analyzed by bioinformatics, and the FANC gene mutations identified by exome sequencing were confirmed by PCR re-sequencing. Results Homozygous and compound heterozygous mutations of FANC genes were identified in all of the patients. The FA subtypes of the patients included FANCA, FANCM and FANCD2. Interestingly, four FA patients harbored multiple mutations in at least two FA genes, and some of these mutations have not been previously reported. These patients’ clinical manifestations were vastly different from each other, as were their treatment responses to androstanazol and prednisone. This finding suggests that heterozygous mutation(s) in FA genes could also have diverse biological and/or pathophysiological effects on FA patients or FA gene carriers. Interestingly, we were not able to identify de novo mutations in the genes implicated in DNA repair pathways when the sequencing data of patients were compared with those of their parents. Conclusions Our results indicate that Chinese FA patients and carriers might have higher and more complex mutation rates in FANC genes than have been conventionally recognized. Testing of the fifteen FANC genes in FA patients and their family members should be a regular clinical practice to determine the optimal care for the individual patient, to counsel the family and to obtain a better understanding of FA pathophysiology. PMID:24885126

2014-01-01

338

Non-existence of caveolin-1 gene mutations in human breast cancer.  

PubMed

Caveolin-1 is the principal constituent protein of caveolae, which are specialised plasma membrane invaginations with diverse biological roles. Caveolin-1 is suggested to have tumour suppressive functions and CAV1 gene mutations have been reported in 20% of breast cancers. The aim of the present study was to evaluate the frequency of CAV1 mutations in a large cohort of optimally accrued breast cancers. Two independent series of breast cancer samples were analysed: 82 fresh-frozen grade 3 and 158 formalin-fixed paraffin-embedded invasive ductal carcinomas of no special type were consecutively accrued and subjected to microdissection of neoplastic epithelial cells prior to DNA extraction. Thirty-nine human breast cancer cell lines were also included in this study. The trans-membrane region of CAV1 and adjacent sequences, where mutations are reported to cluster, were amplified by PCR, followed by direct sequencing and mutational analysis. None of the reported CAV1 gene mutations, including CAV1 (P132L), were identified in either clinical samples (95% CI: 0-1.5%) or human breast cancer cell lines analysed. One novel non-synonymous germline polymorphism was detected within a reported region of high mutational frequency. This study does not corroborate the reported frequent occurrence of CAV1 gene mutations, including CAV1 (P132L), in primary human breast carcinomas. Our findings demonstrate that if CAV1 mutations do exist, their overall mutational frequency is substantially lower than positive reports have suggested. Taken together with other studies, which have also failed to identify CAV1 mutations, our data call into question the existence and biological and clinical relevance of CAV1 gene mutations in human breast cancer. PMID:21909981

Patani, Neill; Lambros, Maryou B; Natrajan, Rachael; Dedes, Konstantin J; Geyer, Felipe C; Ward, Eric; Martin, Lesley-Ann; Dowsett, Mitch; Reis-Filho, Jorge S

2012-01-01

339

Gain-of-function mutations of platelet-derived growth factor receptor ? gene in gastrointestinal stromal tumors  

Microsoft Academic Search

Background & Aims: Most gastrointestinal stromal tumors (GISTs) have gain-of-function mutations of c-kit receptor tyrosine kinase (KIT) gene, but some GISTs do not. We investigated the cause of GISTs without KIT mutations. Because GISTs apparently expressed platelet-derived growth factor receptor (PDGFR) ?, we examined whether GISTs without KIT mutations had a mutation of PDGFR ?. Methods: Whole coding region of

Seiichi Hirota; Akiko Ohashi; Toshirou Nishida; Koji Isozaki; Kazuo Kinoshita; Yasuhisa Shinomura; Yukihiko Kitamura

2003-01-01

340

Immunohistochemical NF1 Analysis Does not Predict NF1 Gene Mutation Status in Pheochromocytoma.  

PubMed

Pheochromocytomas (PCCs) are tumors originating from the adrenal medulla displaying a diverse genetic background. While most PCCs are sporadic, about 40 % of the tumors have been associated with constitutional mutations in one of at least 14 known susceptibility genes. As 25 % of sporadic PCCs harbor somatic neurofibromin 1 gene (NF1) mutations, NF1 has been established as the most recurrently mutated gene in PCCs. To be able to pinpoint NF1-related pheochromocytoma (PCC) disease in clinical practice could facilitate the detection of familial cases, but the large size of the NF1 gene makes standard DNA sequencing methods cumbersome. The aim of this study was to examine whether mutations in the NF1 gene could be predicted by immunohistochemistry as a method to identify cases for further genetic characterization. Sixty-seven PCCs obtained from 67 unselected patients for which the somatic and constitutional mutational status of NF1 was known (49 NF1 wild type, 18 NF1 mutated) were investigated for NF1 protein immunoreactivity, and the results were correlated to clinical and genetic data. NF1 immunoreactivity was absent in the majority of the PCCs (44/67; 66 %), including 13 out of 18 cases (72 %) with a somatic or constitutional NF1 mutation. However, only a minority of the NF1 wild-type PCCs (18/49; 37 %) displayed retained NF1 immunoreactivity, thereby diminishing the specificity of the method. We conclude that NF1 immunohistochemistry alone is not a sufficient method to distinguish between NF1-mutated and non-mutated PCCs. In the clinical context, genetic screening therefore remains the most reliable tool to detect NF1-mutated PCCs. PMID:25403449

Stenman, Adam; Svahn, Fredrika; Welander, Jenny; Gustavson, Boel; Söderkvist, Peter; Gimm, Oliver; Juhlin, C Christofer

2014-11-18

341

[Mutation analysis of the pathogenic gene in a Chinese family with hereditary hemochromatosis].  

PubMed

Hereditary hemochromatosis (HHC) is a rare autosomal recessive disorder. We recruited a consanguineous Chinese family including the proband with HHC and other four members without HHC. Using whole-exome sequencing, we identified two homozygous mutations (c.G18C [p.Q6H] and c.GC962_963AA [p.C321X]) in the hemojuvelin gene (HJV) in the proband with HHC. No mutation was found in other four previously identified HHC related genes, HAMP, TFR2, FPN and HFE. The functional impact of p.Q6H mutation is weak whereas p.C321X, a premature termination mutation, results in a truncated HJV protein, which lacks the glycosylphosphatidylinositol (GPI) anchor domain. In addition to the mutations in HJV, other 12 homozygous mutations were identified in this patient. However, none of these mutations showed strong damaging impact and the mutated genes are not related to iron metabolism. Our in-house data further demonstrated that p.C321X is absent in the general Chinese population, suggesting that the homozygous mutation p.C321X in HJV is causative in the patient with HHC. Accordingly, all of the four members without HHC from the same family carried wild-type alleles or heterozygous mutations, but not the homozygous mutation in this site. Thus, we found for the first time that the homozygous mutation p.C321X in HJV can result in HHC, which will help genetic diagnosis and prenatal counseling for HHC. PMID:25567873

Yuanfeng, Li; Hongxing, Zhang; Haitao, Zhang; Xiaobo, Peng; Lili, Bai; Fuchu, He; Zewu, Qiu; Gangqiao, Zhou

2014-11-01

342

Dystrophin Gene Mutation Location and the Risk of Cognitive Impairment in Duchenne Muscular Dystrophy  

PubMed Central

Background A significant component of the variation in cognitive disability that is observed in Duchenne muscular dystrophy (DMD) is known to be under genetic regulation. In this study we report correlations between standardised measures of intelligence and mutational class, mutation size, mutation location and the involvement of dystrophin isoforms. Methods and Results Sixty two male subjects were recruited as part of a study of the cognitive spectrum in boys with DMD conducted at the Sydney Children's Hospital (SCH). All 62 children received neuropsychological testing from a single clinical psychologist and had a defined dystrophin gene (DMD) mutation; including DMD gene deletions, duplications and DNA point mutations. Full Scale Intelligence Quotients (FSIQ) in unrelated subjects with the same mutation were found to be highly correlated (r?=?0.83, p?=?0.0008), in contrast to results in previous publications. In 58 cases (94%) it was possible to definitively assign a mutation as affecting one or more dystrophin isoforms. A strong association between the risk of cognitive disability and the involvement of groups of DMD isoforms was found. In particular, improvements in the correlation of FSIQ with mutation location were identified when a new classification system for mutations affecting the Dp140 isoform was implemented. Significance These data represent one of the largest studies of FSIQ and mutational data in DMD patients and is among the first to report on a DMD cohort which has had both comprehensive mutational analysis and FSIQ testing through a single referral centre. The correlation between FSIQ results with the location of the dystrophin gene mutation suggests that the risk of cognitive deficit is a result of the cumulative loss of central nervous system (CNS) expressed dystrophin isoforms, and that correct classification of isoform involvement results in improved estimates of risk. PMID:20098710

Maroulis, Sarah; Gilissen, Christian; Pedersen, Robyn L.; Mowat, David R.; Johnston, Heather M.; Buckley, Michael F.

2010-01-01

343

Mutational Analysis of EGFR and Related Signaling Pathway Genes in Lung Adenocarcinomas Identifies a Novel Somatic Kinase Domain Mutation in FGFR4  

PubMed Central

Background Fifty percent of lung adenocarcinomas harbor somatic mutations in six genes that encode proteins in the EGFR signaling pathway, i.e., EGFR, HER2/ERBB2, HER4/ERBB4, PIK3CA, BRAF, and KRAS. We performed mutational profiling of a large cohort of lung adenocarcinomas to uncover other potential somatic mutations in genes of this signaling pathway that could contribute to lung tumorigenesis. Methodology/Principal Findings We analyzed genomic DNA from a total of 261 resected, clinically annotated non-small cell lung cancer (NSCLC) specimens. The coding sequences of 39 genes were screened for somatic mutations via high-throughput dideoxynucleotide sequencing of PCR-amplified gene products. Mutations were considered to be somatic only if they were found in an independent tumor-derived PCR product but not in matched normal tissue. Sequencing of 9MB of tumor sequence identified 239 putative genetic variants. We further examined 22 variants found in RAS family genes and 135 variants localized to exons encoding the kinase domain of respective proteins. We identified a total of 37 non-synonymous somatic mutations; 36 were found collectively in EGFR, KRAS, BRAF, and PIK3CA. One somatic mutation was a previously unreported mutation in the kinase domain (exon 16) of FGFR4 (Glu681Lys), identified in 1 of 158 tumors. The FGFR4 mutation is analogous to a reported tumor-specific somatic mutation in ERBB2 and is located in the same exon as a previously reported kinase domain mutation in FGFR4 (Pro712Thr) in a lung adenocarcinoma cell line. Conclusions/Significance This study is one of the first comprehensive mutational analyses of major genes in a specific signaling pathway in a sizeable cohort of lung adenocarcinomas. Our results suggest the majority of gain-of-function mutations within kinase genes in the EGFR signaling pathway have already been identified. Our findings also implicate FGFR4 in the pathogenesis of a subset of lung adenocarcinomas. PMID:17487277

Marks, Jenifer L.; McLellan, Michael D.; Zakowski, Maureen F.; Lash, Alex E.; Kasai, Yumi; Broderick, Stephen; Sarkaria, Inderpal S.; Pham, DuyKhanh; Singh, Bhuvanesh; Miner, Tracie L.; Fewell, Ginger A.; Fulton, Lucinda L.; Mardis, Elaine R.; Wilson, Richard K.; Kris, Mark G.; Rusch, Valerie W.; Varmus, Harold; Pao, William

2007-01-01

344

Identification of genes that protect the C. elegans genome against mutations by genome-wide RNAi.  

PubMed

An RNA interference (RNAi)-based genome-wide screen was performed to detect genes that contribute to genome stability in somatic cells of Caenorhabditis elegans. We identified 61 such genes; these also affect spontaneous mutagenesis in the germ line. Their sequence suggests a role in DNA repair and/or replication, in chromatin remodeling, or in cell cycle control; there are also many novel genes that are highly conserved from yeast to human. Because known mutator genes are causally involved in many hereditary and sporadic human cancers, it is likely that some of these new mutators are equally relevant in cancer etiology. PMID:12600937

Pothof, Joris; van Haaften, Gijs; Thijssen, Karen; Kamath, Ravi S; Fraser, Andrew G; Ahringer, Julie; Plasterk, Ronald H A; Tijsterman, Marcel

2003-02-15

345

Mutations in genes involved in nonsense mediated decay ameliorate the phenotype of sel-12 mutants with amber stop mutations in Caenorhabditis elegans  

Microsoft Academic Search

BACKGROUND: Presenilin proteins are part of a complex of proteins that can cleave many type I transmembrane proteins, including Notch Receptors and the Amyloid Precursor Protein, in the middle of the transmembrane domain. Dominant mutations in the human presenilin genes PS1 and PS2 lead to Familial Alzheimer's disease. Mutations in the Caenorhabditis elegans sel-12 presenilin gene cause a highly penetrant

Alisson M Gontijo; Sylvie Aubert; Ingele Roelens; Bernard Lakowski

2009-01-01

346

FGFR3 Mutations and the Skin: Report of a Patient with a FGFR3 Gene Mutation, Acanthosis Nigricans, Hypochondroplasia and Hyperinsulinemia and Review of the Literature  

Microsoft Academic Search

Fibroblast growth factor receptor 3 (FGFR3) gene mutations in the germline are well-known causes of skeletal syndromes. Somatic FGFR3 mutations have been found in malignant neoplasms and more recently in several cutaneous elements. We present a 14-year-old girl with mild hypochondroplasia who developed acanthosis nigricans. The report of a K650Q mutation in the FGFR3 gene in a similar case prompted

M. Blomberg; E. M. Jeppesen; F. Skovby; E. Benfeldt

2010-01-01

347

Comprehensive characterization of HNPCC-related colorectal cancers reveals striking molecular features in families with no germline mismatch repair gene mutations  

Microsoft Academic Search

A considerable fraction of families with HNPCC shows no germline mismatch repair (MMR) gene mutations. We previously detected ‘hidden’ MMR gene defects in 42% of such families, leaving the remaining 58% ‘truly’ mutation negative. Here, we characterized 50 colorectal carcinomas and five adenomas arising in HNPCC families; 24 truly MMR gene mutation negative and 31 MMR gene mutation positive. Among

Wael M Abdel-Rahman; Miina Ollikainen; Reetta Kariola; Heikki J Järvinen; Jukka-Pekka Mecklin; Minna Nyström-Lahti; Sakari Knuutila; Päivi Peltomäki

2005-01-01

348

Point Mutations Effects on Charge Transport Properties of the Tumor-Suppressor Gene p53  

E-print Network

We report on a theoretical study of point mutations effects on charge transfer properties in the DNA sequence of the tumor-suppressor p53 gene. On the basis of effective single-strand or double-strand tight-binding models which simulate hole propagation along the DNA, a statistical analysis of charge transmission modulations associated with all possible point mutations is performed. We find that in contrast to non-cancerous mutations, mutation hotspots tend to result in significantly weaker {\\em changes of transmission properties}. This suggests that charge transport could play a significant role for DNA-repairing deficiency yielding carcinogenesis.

Chi-Tin Shih; Stephan Roche; Rudolf A. Römer

2007-08-23

349

Constitutional RB1-gene mutations in patients with isolated unilateral retinoblastoma.  

PubMed Central

In most patients with isolated unilateral retinoblastoma, tumor development is initiated by somatic inactivation of both alleles of the RB1 gene. However, some of these patients can transmit retinoblastoma predisposition to their offspring. To determine the frequency and nature of constitutional RB1-gene mutations in patients with isolated unilateral retinoblastoma, we analyzed DNA from peripheral blood and from tumor tissue. The analysis of tumors from 54 (71%) of 76 informative patients showed loss of constitutional heterozygosity (LOH) at intragenic loci. Three of 13 uninformative patients had constitutional deletions. For 39 randomly selected tumors, SSCP, hetero-duplex analysis, sequencing, and Southern blot analysis were used to identify mutations. Mutations were detected in 21 (91%) of 23 tumors with LOH. In 6 (38%) of 16 tumors without LOH, one mutation was detected, and in 9 (56%) of the tumors without LOH, both mutations were found. Thus, a total of 45 mutations were identified in tumors of 36 patients. Thirty-nine of the mutations-including 34 small mutations, 2 large structural alterations, and hypermethylation in 3 tumors-were not detected in the corresponding peripheral blood DNA. In 6 (17%) of the 36 patients, a mutation was detected in constitutional DNA, and 1 of these mutations is known to be associated with reduced expressivity. The presence of a constitutional mutation was not associated with an early age at treatment. In 1 patient, somatic mosaicism was demonstrated by molecular analysis of DNA and RNA from peripheral blood. In 2 patients without a detectable mutation in peripheral blood, mosaicism was suggested because 1 of the patients showed multifocal tumors and the other later developed bilateral retinoblastoma. In conclusion, our results emphasize that the manifestation and transmissibility of retinoblastoma depend on the nature of the first mutation, its time in development, and the number and types of cells that are affected. Images Figure 2 Figure 3 Figure 4 PMID:9311732

Lohmann, D R; Gerick, M; Brandt, B; Oelschläger, U; Lorenz, B; Passarge, E; Horsthemke, B

1997-01-01

350

Genomic organization of SLC3A1, a transporter gene mutated in cystinuria  

SciTech Connect

The SLC3A1 gene encodes a transport protein for cystine and the dibasic amino acids. Recently mutations in this gene have been shown to cause cystinuria. We report the genomic structure and organization of SLC3A1, which is composed of 10 exons and spans nearly 45 kb. Until now screening for mutations in SLC3A1 has been based on RT-PCR amplification of illegitimate mRNA transcripts from white blood cells. In this report we provide primers for amplification of exons from genomic DNA, thus simplifying the process of screening for SLC3A1 mutations in cystinuria. 20 refs., 3 figs., 2 tabs.

Pras, E.; Sood, R.; Raben, N. [National Inst. of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD (United States)] [National Inst. of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD (United States)

1996-08-15

351

"20209C-T" a variant mutation of prothrombin gene mutation in a patient with recurrent pregnancy loss.  

PubMed

Recurrent pregnancy loss is considered when a female undergoes at least two consecutive, spontaneous abortions or more than two alternatively. This condition affects approximately 5% of women in reproductive age. Several causes of recurrent abortion have been established, but nevertheless, approximately half of all cases remain unexplained. Thrombophilic disorders have been suggested as a possible cause of recurrent miscarriage. A single 20210 G-A mutation of the 3'-untranslated region of (F2) has been reported as a cause of inherited thrombophilia. The F2 G-A mutation affects 1% to 4% of the US population, and its prevalence is higher among Caucasian women of Southern European descendants. Studies of G20210A polymorphism have also shown conflicting associations with recurrent abortions. In addition to G20210A polymorphism, other mutations affecting the F2 gene have been associated with thrombosis and/or pregnancy complications. PMID:25117109

Prat, Maria; Morales-Indiano, Cristian; Jimenez, Carme; Mas, Virgina; Besses, Carles; Checa, Miguel A; Carreras, Ramon

2014-01-01

352

[Detection of germline mutations in the APC gene with the protein truncation test].  

PubMed

The protein truncation test was established for analyzing mutations in the adenomatous polyposis coli (APC) gene which plays an important role in familial adenomatous polyposis (FAP). The sites of APC mutations and the clinic features of FAP patients were examined to find the relationship between them. Genomic DNA, which was extracted from peripheral blood lymphocytes of 22 FAP patients and the normal colon tissues of 43 sporadic colorectal cancers, were examined for mutations in exon15 of the APC gene by using PCR-TNT T7 Quick Coupled Tanscription/Translation System. The subsequent sequencing was used to confirm the mutation sites. Germline mutations were found in 5 of 22 FAP patients. All of the five mutations showed base pair deletions and led to produce truncated protein. No truncating germline mutation was found in normal tissues of 43 sporadic colorectal cancers. The protein truncation test is a sensitive and accurate technique to detect truncated mutations especially in the large exons of APC gene. It can be used as an routine method for assisting the early diagnosis of the FAP patients. PMID:16201232

Liu, Xiao-Rong; Shan, Xiang-Nian; Friedl, W; Uhlhaas, S; Li, Jin-Tian; Propping, P; Wang, Ya-Ping

2005-09-01

353

A mutational hot spot in the KCNQ4 gene responsible for autosomal dominant hearing impairment.  

PubMed

Several different mutations in the KCNQ4 K+ channel gene are responsible for autosomal dominant nonsyndromic hearing impairment (DFNA2). Here we describe two additional families originating from Europe and Japan with a KCNQ4 missense mutation (W276S) that was previously found in one European family. We compared the disease-associated haplotype of the three W276S-bearing families using closely linked microsatellite markers and intragenic single nucleotide polymorphisms. Differences between the haplotypes were found, excluding a single founder mutation for the families. Therefore, the W276S mutation has occurred three times independently, and most likely represents a hot spot for mutation in the KCNQ4 gene. PMID:12112653

Van Camp, Guy; Coucke, Paul J; Akita, Jiro; Fransen, Erik; Abe, Satoko; De Leenheer, Els M R; Huygen, Patrick L M; Cremers, Cor W R J; Usami, Shin-Ichi

2002-07-01

354

Characterization of six mutations in Exon 37 of neurofibromatosis type 1 gene  

SciTech Connect

Neurofibromatosis type 1 (NF1) is one of the most common inherited disorders, with an incidence of 1 in 3,000. We screened a total of 320 unrelated NF1 patients for mutations in exon 37 of the NF1 gene. Six independent mutations were identified, of which three are novel, and these include a recurrent nonsense mutation identified in 2 unrelated patients at codon 2281 (G2281X), a 1-bp insertion (6791 ins A) resulting in a change of TAG (tyrosine) to a TAA (stop codon), and a 3-bp deletion (6839 del TAC) which generated a frameshift. Another recurrent nonsense mutation, Y2264X, which was detected in 2 unrelated patients in this study, was also previously reported in 2 NF1 individuals. All the mutations were identified within a contiguous 49-bp sequence. Further studies are warranted to support the notion that this region of the gene contains highly mutable sequences. 17 refs., 2 figs., 1 tab.

Upadhyaya, M.; Osborn, M.; Maynard, J.; Harper, P. [Institute of Medical Genetics, Cardiff, Wales (United Kingdom)] [Institute of Medical Genetics, Cardiff, Wales (United Kingdom)

1996-07-26

355

A Mutation in the Mitochondrial Fission Gene Dnm1l Leads to Cardiomyopathy  

PubMed Central

Mutations in a number of genes have been linked to inherited dilated cardiomyopathy (DCM). However, such mutations account for only a small proportion of the clinical cases emphasising the need for alternative discovery approaches to uncovering novel pathogenic mutations in hitherto unidentified pathways. Accordingly, as part of a large-scale N-ethyl-N-nitrosourea mutagenesis screen, we identified a mouse mutant, Python, which develops DCM. We demonstrate that the Python phenotype is attributable to a dominant fully penetrant mutation in the dynamin-1-like (Dnm1l) gene, which has been shown to be critical for mitochondrial fission. The C452F mutation is in a highly conserved region of the M domain of Dnm1l that alters protein interactions in a yeast two-hybrid system, suggesting that the mutation might alter intramolecular interactions within the Dnm1l monomer. Heterozygous Python fibroblasts exhibit abnormal mitochondria and peroxisomes. Homozygosity for the mutation results in the death of embryos midway though gestation. Heterozygous Python hearts show reduced levels of mitochondria enzyme complexes and suffer from cardiac ATP depletion. The resulting energy deficiency may contribute to cardiomyopathy. This is the first demonstration that a defect in a gene involved in mitochondrial remodelling can result in cardiomyopathy, showing that the function of this gene is needed for the maintenance of normal cellular function in a relatively tissue-specific manner. This disease model attests to the importance of mitochondrial remodelling in the heart; similar defects might underlie human heart muscle disease. PMID:20585624

Ashrafian, Houman; Docherty, Louise; Leo, Vincenzo; Towlson, Christopher; Neilan, Monica; Steeples, Violetta; Lygate, Craig A.; Hough, Tertius; Townsend, Stuart; Williams, Debbie; Wells, Sara; Norris, Dominic; Glyn-Jones, Sarah; Land, John; Barbaric, Ivana; Lalanne, Zuzanne; Denny, Paul; Szumska, Dorota; Bhattacharya, Shoumo; Griffin, Julian L.; Hargreaves, Iain; Fernandez-Fuentes, Narcis; Cheeseman, Michael; Watkins, Hugh; Dear, T. Neil

2010-01-01

356

Iron overload and HFE gene mutations in Czech patients with chronic liver diseases.  

PubMed

The aim of the study was to identify the prevalence of HFE gene mutations in Czech patients with chronic liver diseases and the influence of the mutations on iron status. The presence of HFE gene mutations (C282Y, H63D, and S65C) analyzed by the PCR-RFLP method, presence of cirrhosis, and serum iron indices were compared among 454 patients with different chronic liver diseases (51 with chronic hepatitis B, 122 with chronic hepatitis C, 218 with alcoholic liver disease, and 63 patients with hemochromatosis). Chronic liver diseases patients other than hemochromatics did not have an increased frequency of HFE gene mutations compared to controls. Although 33.3% of patients with hepatitis B, 43% of patients with hepatitis C, and 73.2% of patients with alcoholic liver disease had elevated transferrin saturation or serum ferritin levels, the presence of HFE gene mutations was not significantly associated with iron overload in these patients. Additionally, patients with cirrhosis did not have frequencies of HFE mutations different from those without cirrhosis. This study emphasizes the importance, not only of C282Y, but also of the H63D homozygous genetic constellation in Czech hemochromatosis patients. Our findings show that increased iron indices are common in chronic liver diseases but {\\it HFE} mutations do not play an important role in the pathogenesis of chronic hepatitis B, chronic hepatitis C, and alcoholic liver disease. PMID:22297603

Dostalikova-Cimburova, Marketa; Kratka, Karolina; Stransky, Jaroslav; Putova, Ivana; Cieslarova, Blanka; Horak, Jiri

2012-01-01

357

Mutation Analysis of the APC Gene in a Chinese FAP Pedigree with Unusual Phenotype.  

PubMed

Background and Aim. Germline mutations of the adenomatous polyposis coli (APC) gene cause familial adenomatous polyposis (FAP), an autosomal dominant inherited disease mainly characterized by colorectal adenomatous polyposis. Genetic studies of FAP have shown that somatic APC mutations are dependent on the position of the germline APC mutation. However, the molecular mechanism underlying these genotype-phenotype associations for APC in Chinese remain largely unknown. Patients and Methods. In this study, we investigated the APC gene mutation in a Chinese FAP family by systematic screening with multiplex ligation-dependent probe amplification (MLPA), denaturing high-performance liquid chromatography (dHPLC), and DNA sequencing. Promoter methylation was detected by methylation-specific PCR. Results. The identical germline mutation c.1999 C>T (Q667X) of APC was identified in 5 affected members, among which 2 members carried somatic mutations of APC, one with promoter hypermethylation and the other with loss of wild-type allele in their adenomas. The somatic mutations were shown connected with the disease severity, demonstrating a unique genotype-phenotype association in this FAP pedigree. Conclusion. The study revealed the existence of novel pathogenic mutations in Chinese patients with FAP. Somatic mutations are of particular interest because of the unusual phenotypic features shown by patients. PMID:22164339

Chen, S; Zhou, J; Zhang, X; Zhou, X; Zhu, M; Zhang, Y; Ma, G; Li, J

2011-01-01

358

Investigation of mutations in Erg11 gene of fluconazole resistant Candida albicans isolates from Turkish hospitals.  

PubMed

Widespread use of fluconazole has resulted in resistance in strains of Candida. The aim of our study was to investigate Y132H and other mutations in the ERG11 gene in conferring fluconazole resistance to C. albicans isolates. Seven fluconazole-resistant (R)/susceptible dose-dependent (SDD)/trailing and 10 fluconazole-susceptible (S) isolates were included. Restriction enzyme analysis was performed on all isolates for Y132H mutation and sequence analysis was performed for other mutations in the ERG11 gene. None of our strains had Y132H mutation. One single mutation (D153E, E266D, D116E, V437I) was detected in isolates 348, 533, 644, 1453, 2157, while the others had more than one nucleotide change. D116E and E266D, which were two mutations found in fluconazole R/SDD/trailing isolates with the highest frequency, were also detected in azole S strains. K143R, G464S, G465S and V488I mutations were determined in three of the R/SDD isolates. S412T and R469K mutations were detected only in this group of strains by sequence analysis. Mutations such as K143R, G464S, G465S, V488I, S412T and R469K in the ERG11 gene were determined to be effective mechanisms in our fluconazole R/SDD C. albicans isolates. Other mechanisms of resistance, such as overexpression of ERG11 and efflux pumps and mutations in the ERG3 gene should also be investigated. PMID:19732347

Manast?r, Lerzan; Ergon, M Cem; Yücesoy, Mine

2011-03-01

359

Identification and in silico analysis of 14 novel GJB1, MPZ and PMP22 gene mutations  

PubMed Central

Duplication within the chromosome 17p11.2 (CMT1Adup), peripheral myelin protein 22 (PMP22), myelin protein zero (MPZ) and gap junction ?1-protein (GJB1) gene mutations are frequent causes of the Charcot-Marie-Tooth disease (CMT). A large number of mutations in these genes are listed in databases. Sequence variants identified in patients are frequently reported as mutations without further evaluation. We analyzed 250 consecutively recruited unrelated Austrian CMT patients for CMT1Adup by microsatellite marker typing, real-time PCR or MLPA, and found 79 duplications (31.6%). The coding regions of the PMP22, MPZ and GJB1 genes were analyzed by direct sequencing in the remaining patients; 28 patients showed mutations, 14 of which were novel. We scored the pathogenicity of novel missense mutations by segregation studies and by their exclusion in control samples. Our comprehensive literature study found that up to 60% of the reported mutations in these genes had not been evaluated regarding their pathogenicity, and the PANTHER bioinformatics tool was used to score novel and published missense variants. The PANTHER program scored known polymorphisms as such, but scored ?82–88% only of the published and novel mutations as most likely deleterious. Mutations associated with axonal CMT were less likely to be classified as deleterious, and the PMP22 S72L mutation repeatedly associated with severe CMT was classified as a polymorphism using default parameters. Our data suggest that this in silico analysis tool could be useful for assessing the functional impact of DNA variations only as a complementary approach. The CMT1Adup, GJB1, MPZ and PMP22 mutation frequencies were in the range of those described in other CMT patient collectives with different ethnical backgrounds. PMID:19259128

Miltenberger-Miltenyi, Gabriel; Schwarzbraun, Thomas; Löscher, Wolfgang N; Wanschitz, Julia; Windpassinger, Christian; Duba, Hans-Christoph; Seidl, Rainer; Albrecht, Gerhard; Weirich-Schwaiger, Helga; Zoller, Heinz; Utermann, Gerd; Auer-Grumbach, Michaela; Janecke, Andreas R

2009-01-01

360

Mutation spectrum in BBS genes guided by homozygosity mapping in an Indian cohort.  

PubMed

Bardet-Biedl syndrome (BBS), a ciliopathy disorder with pleiotropic effect manifests primarily as retinal degeneration along with renal insufficiency, polydactyly and obesity. In this study, we have performed homozygosity mapping using NspI 250K affymetrix gene chip followed by mutation screening of the candidate genes located in the homozygous blocks. These regions are prioritized based on the block length and candidature of the genes in BBS and other ciliopathies. Gene alterations in known BBS (22) and other ciliopathy genes such as ALMS1 (2) were seen in 24 of 30 families (80%). Mutations in BBS3 gene, inclusive of a novel recurrent mutation (p.I91T) accounted for 18% of the identified variations. Disease associated polymorphisms p.S70N (BBS2), rs1545 and rs1547 (BBS6) were also observed. This is the first study in Indian BBS patients and homozygosity mapping has proved to be an effective tool in prioritizing the candidate genes in consanguineous pedigrees. The study reveals a different mutation profile in the ciliopathy genes in Indian population and implication of novel loci/genes in 20% of the study group. PMID:24400638

Sathya Priya, C; Sen, P; Umashankar, V; Gupta, N; Kabra, M; Kumaramanickavel, G; Stoetzel, C; Dollfus, H; Sripriya, S

2015-02-01

361

A bacterial model for expression of mutations in the human ornithine transcarbamylase (OTC) gene  

SciTech Connect

OTC is a mitochondrial enzyme catalyzing the formation of citrulline from carbamyl phosphate and ornithine. X-linked deficiency of OTC is the most prevalent genetic defect of ureagenesis. Mutations and polymorphisms in the OTC gene identified in deficient patients have indicated the occurrence of many family-specific, unique alleles. Due to the low frequency of recurrent mutations, distinguishing between deleterious mutations and polymorphisms is difficult. Using a human OTC gene containing plasmid driven by a tac promoter, we have devised a simple and efficient method for expressing mutations in the mature human OTC enzyme. To demonstrate this method, PCR engineered site-directed mutagenesis was employed to generated cDNA fragments which contained either the R151Q or R277W known mutations found in patients with neonatal and late-onset OTC deficiency, respectively. The normal allele for each mutation was also generated by an identical PCR procedure. Digestion with Bgl II- and Sty I-generated mutant and normal replacement cassettes containing the respective mutant and wild type sequences. Upon transformation of JM109 E.coli cells, OTC enzymatic activity was measured at log and stationary phases of growth using a radiochromatographic method. The R141Q mutation abolished enzymatic activity (<0.02% of normal), whereas the R277W mutation expressed partial activity (2.3% of normal). In addition, a PCR-generated mutation, A280V, resulted in 73% loss of catalytic activity. This OTC expression system is clinically applicable for distinguishing between mutations and polymorphisms, and it can be used to investigate the effects of mutations on various domains of the OTC gene.

Tuchman, M.; McCann, M.T.; Qureshi, A.A. [Univ. of Minnesota, Mineapolis (United States)

1994-09-01

362

Insulin-like factor 3 gene mutations in testicular dysgenesis syndrome: clinical and functional characterization.  

PubMed

Insulin-like factor 3 (INSL3) plays a crucial role in testicular descent. Genetic ablation of Insl3 or its G protein-coupled receptor, leucine-rich repeat-containing G-protein-coupled receptor (Lgr8), causes cryptorchidism in mice. Mutation analyses of INSL3 in humans showed an association with cryptorchidism but led to non-conclusive data about a causative role. In this study, we explored the hypothesis that mutations in INSL3 may be associated with the signs of testicular dysgenesis syndrome (TDS). We screened for mutations in INSL3 gene in 967 subjects with a history of maldescended testes and/or infertility and/or testicular cancer and in 450 controls. Furthermore, we carried out in vitro functional analysis of three novel mutations by analysis of INSL3-dependent cAMP increase in cells expressing LGR8. We found six INSL3 mutations in 18 of 967 patients (1.9%) and no mutations in controls. Prevalence of mutations was similar in the different groups of patients (cryptorchidism and/or infertility and/testicular cancer). Three mutations were novel findings (R4H, W69R, and R72K); however, their analysis showed normal cAMP increase after the activation of LGR8 receptor. In conclusion, we found a significant association of INSL3 gene mutations in men presenting one or more signs of TDS syndrome. However, a causative role for some of these mutations is not clearly supported by functional analyses. Although a role for mutations of INSL3 and LGR8 genes in cryptorchidism is reasonable, additional studies are needed to establish an association between the disruption of INSL3 pathway and higher risk of infertility or testicular cancer. PMID:16687567

Ferlin, A; Bogatcheva, N V; Gianesello, L; Pepe, A; Vinanzi, C; Agoulnik, A I; Foresta, C

2006-06-01

363

Mutations of 3c and spike protein genes correlate with the occurrence of feline infectious peritonitis.  

PubMed

The genes encoding accessory proteins 3a, 3b, 3c, 7a and 7b, the S2 domain of the spike (S) protein gene and the membrane (M) protein gene of feline infectious peritonitis virus (FIPV) and feline enteric coronavirus (FECV) samples were amplified, cloned and sequenced. For this faeces and/or ascites samples from 19 cats suffering from feline infectious peritonitis (FIP) as well as from 20 FECV-infected healthy cats were used. Sequence comparisons revealed that 3c genes of animals with FIP were heavily affected by nucleotide deletions and point mutations compared to animals infected with FECV; these alterations resulted either in early termination or destruction of the translation initiation codon. Two ascites-derived samples of cats with FIP which displayed no alterations of ORF3c harboured mutations in the S2 domain of the S protein gene which resulted in amino acid exchanges or deletions. Moreover, changes in 3c were often accompanied by mutations in S2. In contrast, in samples obtained from faeces of healthy cats, the ORF3c was never affected by such mutations. Similarly ORF3c from faecal samples of the cats with FIP was mostly intact and showed only in a few cases the same mutations found in the respective ascites samples. The genes encoding 3a, 3b, 7a and 7b displayed no mutations linked to the feline coronavirus (FCoV) biotype. The M protein gene was found to be conserved between FECV and FIPV samples. Our findings suggest that mutations of 3c and spike protein genes correlate with the occurrence of FIP. PMID:25150756

Bank-Wolf, Barbara Regina; Stallkamp, Iris; Wiese, Svenja; Moritz, Andreas; Tekes, Gergely; Thiel, Heinz-Jürgen

2014-10-10

364

Mutational landscape of gingivo-buccal oral squamous cell carcinoma reveals new recurrently-mutated genes and molecular subgroups  

PubMed Central

Gingivo-buccal oral squamous cell carcinoma (OSCC-GB), an anatomical and clinical subtype of head and neck squamous cell carcinoma (HNSCC), is prevalent in regions where tobacco-chewing is common. Exome sequencing (n=50) and recurrence testing (n=60) reveals that some significantly and frequently altered genes are specific to OSCC-GB (USP9X, MLL4, ARID2, UNC13C and TRPM3), while some others are shared with HNSCC (for example, TP53, FAT1, CASP8, HRAS and NOTCH1). We also find new genes with recurrent amplifications (for example, DROSHA, YAP1) or homozygous deletions (for example, DDX3X) in OSCC-GB. We find a high proportion of C>G transversions among tobacco users with high numbers of mutations. Many pathways that are enriched for genomic alterations are specific to OSCC-GB. Our work reveals molecular subtypes with distinctive mutational profiles such as patients predominantly harbouring mutations in CASP8 with or without mutations in FAT1. Mean duration of disease-free survival is significantly elevated in some molecular subgroups. These findings open new avenues for biological characterization and exploration of therapies. PMID:24292195

Maitra, Arindam; Biswas, Nidhan K.; Amin, Kishore; Kowtal, Pradnya; Kumar, Shantanu; Das, Subrata; Sarin, Rajiv; Majumder, Partha P.; Bagchi, I; Bairagya, B. B.; Basu, A.; Bhan, M. K.; Chaturvedi, P.; Das, D.; D'Cruz, A.; Dhar, R.; Dutta, D.; Ganguli, D.; Gera, P.; Gupta, T.; Mahapatra, S.; Mujawar, M. H. K.; Mukherjee, S.; Nair, S.; Nikam, S.; Nobre, M.; Patil, A.; Patra, S.; Rama-Gowtham, M.; Rao, T. S.; Roy, B.; Roychowdhury, B.; Sarkar, D.; Sarkar, S.; Sarkar-Roy, N.; Sutradhar, D.

2013-01-01

365

A nonsense mutation in the LDL receptor gene leads to familial hypercholesterolemia in the Druze sect  

SciTech Connect

Familial hypercholesterolemia (FH) is an autosomal dominant disease caused by mutations in the LDL receptor gene. Here the authors characterize and LDL receptor mutation that is associated with a distinct haplotype and causes FH in the Druze, a small Middle Eastern Islamic sect with a high degree of inbreeding. The mutation was found in FH families from two distinct Druze villages from the Golan Heights (northern Israel). It was not found either in another Druze FH family residing in a different geographical area nor in eight Arab and four Jewish FH heterozygote index cases whose hypercholesterolemia cosegregates with an identical LDL receptor gene haplotype. The mutation, a single-base substitution, results in a termination codon in exon 4 of the LDL receptor gene that encodes for the fourth repeat of the binding domain of the mature receptor. It can be diagnosed by allele-specific oligonucleotide hybridization of PCR-amplified DNA from FH patients.

Landsberger, D.; Meiner, V.; Reshef, A.; Leitersdorf, E. (Hadassah University Hospital, Jerusalem (Israel)); Levy, Yishai (Rambam Medical Center and Faculty of Medicine, Haifa (Israel)); Westhytzen, D.R. van der; Coetzee, G.A. (University of Cape Town Medical School, (South Africa))

1992-02-01

366

[Detection of a gene mutation in familial adenomatous polyposis families by PCR-RFLP method].  

PubMed

A simple and rapid PCR-RFLP method was used to detect a mutation hotspot of adenomatous polyposis coli (APC) gene. Among seven familial adenomatous polyposis (FAP) families, we found individuals in family FD carrying a mutated APC gene or a mutated APC allele with AAAGA deletion in codon 1,309 region. Two young affected persons in twenties were detected by screening the family FD kindred with this PCR-RFLP method. The results are in good accordance with those of colonoscopic examination. The PCR-RFLP method we established proves to be a reliable and simple technique for early detection of some FAP patients. The results indicated the existence of same kind of APC gene mutations in Chinese FAP families as those in western countries. PMID:7994644

Gan, Y B; Zheng, S; Cai, X H

1994-06-01

367

A common FGFR3 gene mutation is present in achondroplasia but not in hypochondroplasia  

SciTech Connect

Achondroplasia is the most common type of genetic dwarfism. It is characterized by disproportionate short stature and other skeletal anomalies resulting from a defect in the maturation of the chondrocytes in the growth plate of the cartilage. Recent studies mapped the achondroplasia gene on chromosome region 4p16.3 and identified a common mutation in the gene encoding the fibroblast growth factor receptor 3 (FGFR3). In an analysis of 19 achondroplasia families from a variety of ethnic backgrounds we confirmed the presence of the G380R mutation in 21 of 23 achondroplasia chromosomes studied. In contrast, the G380R mutation was not found in any of the 8 hypochondroplasia chromosomes studied. Futhermore, linkage studies in a 3-generation family with hypochondroplasia show discordant segregation with markers in the 4p16.3 region suggesting that at least some cases of hypochondroplasia are caused by mutations in a gene other than FGFR3. 27 refs., 2 figs.

Stoilov, I.; Kilpatrick, M.W.; Tsipouras, P. [Univ. of Connecticut Health Center, Farmington, CT (United States)

1995-01-02

368

[Search for frequently encountered mutations in genes predisposing to breast cancer].  

PubMed

DNA of oncological patients, including Ashkenazi Jews and Slavs, living in St. Petersburg was collected, and the resultant collection was screened for three common mutations of genes BRCA1 and BRCA2 by means of heteroduplex analysis. The mutation 5382insC in exon 20 of the BRCA1 gene was found in four unrelated patients, including three Slavs and one Ashkenazi Jew, with a positive family history of breast cancer. The mutations 185delAG and 6174delT in the BRCA1 and BRCA2 genes, respectively, which are typical of Ashkenazi Jewish patients with breast cancer, were not found in the patients of either ethnicity living in St. Petersburg, although the 6174delT mutation was found in the control group of Ashkenazi Jews. A new 12-nucleotide duplication g.71741ins12nt found in intron 20 of the BRCA1 gene was described. The high frequency of the 5382insC mutation in the BRCA1 gene in patients with familial breast cancer in both St. Petersburg and Moscow indicates that Russian families with the history of breast cancer should be primarily tested for this mutation. PMID:11785296

Mandel'shtam, M Iu; Golubkov, V I; Lamber, E P; Shapiro, I M; Brezhneva, T V; Semiglazov, V F; Lipovetski?, B M; Hanson, K P; Ga?tskhoki, V S

2001-12-01

369

Frequent mutation of histone modifying genes in non-Hodgkin lymphoma  

PubMed Central

Follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) are the two most common non-Hodgkin lymphomas (NHLs). To identify genes with mutations in B-cell NHL we sequenced tumour and matched normal DNA from 13 DLBCL cases and one FL case. We analysed RNA-seq data from these and another 113 NHLs to identify genes with candidate mutations, and then re-sequenced tumour and matched normal DNA from these cases to confirm 109 genes with multiple somatic mutations. Genes with roles in histone modification were frequent targets of somatic mutation. For example, 32% of DLBCL and 89% of FL cases had somatic mutations in MLL2, which encodes a histone methyltransferase. 11.4% of DLBCL and 13.4% of FL cases had somatic mutations in MEF2B, a calcium-regulated gene that cooperates with CREBBP and EP300 in acetylating histones. Our analysis thus suggests a previously unappreciated disruption of chromatin biology in lymphomagenesis. PMID:21796119

Morin, Ryan D.; Mendez-Lago, Maria; Mungall, Andrew J.; Goya, Rodrigo; Mungall, Karen L.; Corbett, Richard; Johnson, Nathalie A.; Severson, Tesa M.; Chiu, Readman; Field, Matthew; Jackman, Shaun; Krzywinski, Martin; Scott, David W.; Trinh, Diane L.; Tamura-Wells, Jessica; Li, Sa; Firme, Marlo; Rogic, Sanja; Griffith, Malachi; Chan, Susanna; Yakovenko, Oleksandr; Meyer, Irmtraud M.; Zhao, Eric Y.; Smailus, Duane; Moksa, Michelle; Chittaranjan, Suganthi; Rimsza, Lisa; Brooks-Wilson, Angela; Spinelli, John J.; Ben-Neriah, Susana; Meissner, Barbara; Woolcock, Bruce; Boyle, Merrill; McDonald, Helen; Tam, Angela; Zhao, Yongjun; Delaney, Allen; Zeng, Thomas; Tse, Kane; Butterfield, Yaron; Birol, Inanc; Holt, Rob; Schein, Jacqueline; Horsman, Douglas E.; Moore, Richard; Jones, Steven J.M.; Connors, Joseph M.; Hirst, Martin; Gascoyne, Randy D.; Marra, Marco A.

2011-01-01

370

Mutations of the tyrosinase gene in Indo-Pakistani patients with type I (tyrosinase-deficient) oculocutaneous albinsm (OCA)  

SciTech Connect

Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by deficient synthesis of melanin pigment. Type I (tyrosinase-deficient) OCA results from mutations of the tyrosinase gene (TYR gene) encoding tyrosinase, the enzyme that catalyzes the first two steps of melanin biosynthesis. Mutations of the TYR gene have been identified in a large number of patients, most of Caucasian ethnic origin, with various forms of type I OCA. The authors present an analysis of the TYR gene in eight Indo-Pakistani patients with type I OCA. The authors describe four novel TYR gene mutations and a fifth mutation previously observed in a Caucasian patient. 16 refs., 6 figs.

Tripathi, R.K.; Droetto, S.; Strunk, K.M.; Holmes, S.A.; Spritz, R.A. (Univ. of Wisconsin, Madison, WI (United States)); Bundey, S.; Musarella, M.A.

1993-12-01

371

Five novel CNGB3 gene mutations in Polish patients with achromatopsia  

PubMed Central

Purpose To identify the genetic basis of achromatopsia (ACHM) in four patients from four unrelated Polish families. Methods In this study, we investigated probands with a clinical diagnosis of ACHM. Ophthalmologic examinations, including visual acuity testing, color vision testing, and full-field electroretinography (ERG), were performed in all patients (with the exception of patient p4, who had no ERG). Direct DNA sequencing encompassing the entire coding region of the CNGB3 gene, eight exons of the GNAT2 gene, and exons 5–7 of the CNGA3 gene was performed. Segregation analysis for the presence and independent inheritance of two mutant alleles was performed in the three families available for study. Results All patients showed typical achromatopsia signs and symptoms. Sequencing helped detect causative changes in the CNGB3 gene in all probands. Eight different mutations were detected in the CNGB3 gene, including five novel mutations: two splice site mutations (c.1579–1G>A and c.494–2A>T), one nonsense substitution (c.1194T>G), and two frame-shift mutations (c.393_394delGCinsTCCTGGTGA and c.1366delC). We also found three mutations: one splice site (c.1578+1G>A) and two frame-shift deletions that had been previously described (c.819_826del and c.1148delC). All respective parents were shown to be heterozygous carriers for the mutation detected in their children. Conclusions The present study reports five novel mutations in the CNGB3 gene, and thus broadens the spectrum of probably pathogenic mutations associated with ACHM. Together with molecular data, we provide a brief clinical description of the affected individuals.

Kohl, Susanne; Baumann, Britta; Walczak-Sztulpa, Joanna; Wicher, Katarzyna; Skorczyk-Werner, Anna; Krawczynski, Maciej R.

2014-01-01

372

Disruption Mutations of ADA2b and GCN5 Transcriptional Adaptor Genes Dramatically Affect Arabidopsis Growth, Development, and Gene Expression  

Microsoft Academic Search

We previously identified Arabidopsis genes homologous with the yeast ADA2 and GCN5 genes that encode components of the ADA and SAGA histone acetyltransferase complexes. In this report, we explore the biological roles of the Arabidopsis ADA2b and GCN5 genes. T-DNA insertion mutations in ADA2b and GCN5 were found to have pleiotropic effects on plant growth and development, including dwarf size,

Konstantinos E. Vlachonasios; Michael F. Thomashow; Steven J. Triezenberg

2003-01-01

373

Novel CFTR gene mutation in a patient with CBAVD  

Microsoft Academic Search

We report a novel mutation detected in a 33 year old Chinese man with congenital bilateral absence of the vas deferens (CBAVD), a past history of pulmonary meliodosis infection and a past history of bronchiolitis obliterans organising pneumonia.A novel splice site mutation in intron 6b (1001+5 G?A) in the homozygous state was identified, and was predicted to lead to inefficient

Denise L. M. Goh; Youyou Zhou; Samuel S. Chong; Nicola S. P. Ngiam; Daniel Y. T. Goh

2007-01-01

374

Mutation analysis of pre-mRNA splicing genes in Chinese families with retinitis pigmentosa  

PubMed Central

Purpose Seven genes involved in precursor mRNA (pre-mRNA) splicing have been implicated in autosomal dominant retinitis pigmentosa (adRP). We sought to detect mutations in all seven genes in Chinese families with RP, to characterize the relevant phenotypes, and to evaluate the prevalence of mutations in splicing genes in patients with adRP. Methods Six unrelated families from our adRP cohort (42 families) and two additional families with RP with uncertain inheritance mode were clinically characterized in the present study. Targeted sequence capture with next-generation massively parallel sequencing (NGS) was performed to screen mutations in 189 genes including all seven pre-mRNA splicing genes associated with adRP. Variants detected with NGS were filtered with bioinformatics analyses, validated with Sanger sequencing, and prioritized with pathogenicity analysis. Results Mutations in pre-mRNA splicing genes were identified in three individual families including one novel frameshift mutation in PRPF31 (p.Leu366fs*1) and two known mutations in SNRNP200 (p.Arg681His and p.Ser1087Leu). The patients carrying SNRNP200 p.R681H showed rapid disease progression, and the family carrying p.S1087L presented earlier onset ages and more severe phenotypes compared to another previously reported family with p.S1087L. In five other families, we identified mutations in other RP-related genes, including RP1 p. Ser781* (novel), RP2 p.Gln65* (novel) and p.Ile137del (novel), IMPDH1 p.Asp311Asn (recurrent), and RHO p.Pro347Leu (recurrent). Conclusions Mutations in splicing genes identified in the present and our previous study account for 9.5% in our adRP cohort, indicating the important role of pre-mRNA splicing deficiency in the etiology of adRP. Mutations in the same splicing gene, or even the same mutation, could correlate with different phenotypic severities, complicating the genotype–phenotype correlation and clinical prognosis. PMID:24940031

Pan, Xinyuan; Chen, Xue; Liu, Xiaoxing; Gao, Xiang; Kang, Xiaoli; Xu, Qihua; Chen, Xuejuan; Zhao, Kanxing; Zhang, Xiumei; Chu, Qiaomei; Wang, Xiuying

2014-01-01

375

Mutation survey of candidate genes in 40 Chinese patients with congenital ectopia lentis  

PubMed Central

Purpose To identify the spectrum and frequency of five candidate genes in Chinese patients with congenital ectopia lentis (EL). Methods Forty consecutive and unrelated congenital probands with EL were collected and underwent ocular, skeletal, and cardiovascular examinations. Sanger sequencing was used to analyze all of the coding and adjacent regions of five candidate genes: FBN1, ADAMTS10, ADAMTSL4, TGFBR2, and CBS. Mutation analysis was performed to evaluate the pathogenic variants and to identify the cause of congenital EL. Results The FBN1 gene screen revealed 25 pathogenic variants in 34 of the 40 families with congenital EL, including three novel (c.1955G>T, c.2222delA, and c.4381T>C) and 22 known mutations. The ADAMTSL10 gene screen revealed a compound heterozygous variant (c.1586G>A and c.2485T>A) in a family with Weill-Marchesani syndrome (WMS). In the remaining five probands, no pathogenic variant was detected in any of the five screened genes. Conclusions In this study, we identified three novel and 22 known mutations in FBN1 in 34 of 40 EL families. The results expand the mutation spectrum of the FBN1 gene and suggest that FBN1 mutations may be the major cause of congenital EL in Chinese patients. PMID:25053872

Li, Jie; Jia, Xiaoyun; Li, Shiqiang; Fang, Shaohua

2014-01-01

376

Mutation analysis of the APC gene in Taiwanese FAP families: low incidence of APC germline mutation in a distinct subgroup of FAP families.  

PubMed

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. The affected individuals develop colorectal polyposis and show various extra-colonic manifestations. In this study, we aimed to investigate the genetic and clinical characteristics of FAP in Taiwanese families and analyze the genotype-phenotype correlations. Blood samples were obtained from 66 FAP patients registered in the hereditary colorectal cancer database. Then, germline mutations in the APC genes of these 66 polyposis patients from 47 unrelated FAP families were analyzed. The germline-mutation-negative cases were analyzed by performing multiplex ligation-dependent probe amplification (MLPA) and single-strand conformation polymorphism (SSCP) analysis of the MUTYH gene. Among the analyzed families, 79% (37/47) of the families showed 28 APC mutations, including 19 frameshift mutations, 4 nonsense mutations, 3 genomic deletion mutations, 1 missense mutation, and 1 splice-site mutation. In addition, we identified 15 novel mutations in 32% (15/47) of the families. The cases in which APC mutations were not identified showed significantly lower incidence of profuse polyposis (P = 0.034) and gastroduodenal polyps (P = 0.027). Furthermore, FAP families in which some affected individuals had less than 100 polyps showed significant association with low incidence of APC germline mutations (P = 0.002). We have added the APC germline-mutation data for Taiwanese FAP patients and indicated the presence of an FAP subgroup comprising affected individuals with nonadenomatous polyps or less than 100 adenomatous polyps; this form of FAP is less frequently caused by germline mutations of the APC gene. PMID:19768578

Chiang, J M; Chen, H W; Tang, R P; Chen, J S; Changchien, C R; Hsieh, P S; Wang, J Y

2010-06-01

377

Mutations in topoisomerase genes of fluoroquinolone-resistant salmonellae in Hong Kong.  

PubMed

A total of 88 salmonella isolates (72 clinical isolates for which the ciprofloxacin MIC was >0.06 microg/ml, 15 isolates for which the ciprofloxacin MIC was < or =0.06 microg/ml, and Salmonella enterica serotype Typhimurium ATCC 13311) were studied for the presence of genetic alterations in four quinolone resistance genes, gyrA, gyrB, parC, and parE, by multiplex PCR amplimer conformation analysis. The genetic alterations were confirmed by direct nucleotide sequencing. A considerable number of strains had a mutation in parC, the first to be reported in salmonellae. Seven of the isolates sensitive to 0.06 micro g of ciprofloxacin per ml had a novel mutation at codon 57 of parC (Tyr57-->Ser) which was also found in 29 isolates for which ciprofloxacin MICs were >0.06 micro g/ml. Thirty-two isolates had a single gyrA mutation (Ser83-->Phe, Ser83-->Tyr, Asp87-->Asn, Asp87-->Tyr, or Asp87-->Gly), 34 had both a gyrA mutation and a parC mutation (29 isolates with a parC mutation of Tyr57-->Ser and 5 isolates with a parC mutation of Ser80-->Arg). Six isolates which were isolated recently (from 1998 to 2001) were resistant to 4 micro g of ciprofloxacin per ml. Two of these isolates had double gyrA mutations (Ser83-->Phe and Asp87-->Asn) and a parC mutation (Ser80-->Arg) (MICs, 8 to 32 microg/ml), and four of these isolates had double gyrA mutations (Ser83-->Phe and Asp87-->Gly), one parC mutation (Ser80-->Arg), and one parE mutation (Ser458-->Pro) (MICs, 16 to 64 micro g/ml). All six of these isolates and those with a Ser80-->Arg parC mutation were S. enterica serotype Typhimurium. One S. enterica serotype Typhi isolate harbored a single gyrA mutation (Ser83-->Phe), and an S. enterica serotype Paratyphi A isolate harbored a gyrA mutation (Ser83-->Tyr) and a parC mutation (Tyr57-->Ser); both of these isolates had decreased susceptibilities to the fluoroquinolones. The MICs of ciprofloxacin, levofloxacin, and sparfloxacin were in general the lowest of those of the six fluoroquinolones tested. Isolates with a single gyrA mutation were less resistant to fluoroquinolones than those with an additional parC mutation (Tyr57-->Ser or Ser80-->Arg), while those with double gyrA mutations were more resistant. PMID:14576119

Ling, J M; Chan, E W; Lam, A W; Cheng, A F

2003-11-01

378

Variation in mutation rate and polymorphism among mitochondrial genes of Silene vulgaris.  

PubMed

The prevailing wisdom of the plant mitochondrial genome is that it has very low substitution rates, thus it is generally assumed that nucleotide diversity within species will also be low. However, recent evidence suggests plant mitochondrial genes may harbor variable and sometimes high levels of within-species polymorphism, a result attributed to variance in the influence of selection. However, insufficient attention has been paid to the effect of among-gene variation in mutation rate on varying levels of polymorphism across loci. We measured levels of polymorphism in seven mitochondrial gene regions across a geographically wide sample of the plant Silene vulgaris to investigate whether individual mitochondrial genes accumulate polymorphisms equally. We found that genes vary significantly in polymorphism. Tests based on coalescence theory show that the genes vary significantly in their scaled mutation rate, which, in the absence of differences among genes in effective population size, suggests these genes vary in their underlying mutation rate. Further evidence that among-gene variance in polymorphism is due to variation in the underlying mutation rate comes from a significant positive relationship between the number of segregating sites and silent site divergence from an outgroup. Contrary to recent studies, we found unconvincing evidence of recombination in the mitochondrial genome, and generally confirm the standard model of plant mitochondria characterized by low substitution rates and no recombination. We also show no evidence of significant variation in the strength or direction of selection among genes; this result may be expected if there is no recombination. The present study provides some of the most thorough data on plant mitochondrial polymorphism, and provides compelling evidence for mutation rate variation among genes. The study also demonstrates the difficulty in establishing a null model of mitochondrial genome polymorphism, and thus the difficulty, in the absence of a comparative approach, in testing the assumption that low substitution rates in plant mitochondria lead to low polymorphism. PMID:17533174

Barr, Camille M; Keller, Stephen R; Ingvarsson, Pär K; Sloan, Daniel B; Taylor, Douglas R

2007-08-01

379

Study on the Evolution of Genes Mutation Related With Gastrointestinal Stromal Tumors  

ClinicalTrials.gov

Full Gene Sequences of c-KIT?PDGFRA and DOG1 Are Analyzed With the Screening-sequencing Approach; Investigate the Characteristics and Variations Associated With the Different Gene Mutations of c-KIT?PDGFRA and DOG1 in GIST Patients

2012-01-05

380

Accumulation of slightly deleterious mutations in mitochondrial protein-coding genes of  

E-print Network

Accumulation of slightly deleterious mutations in mitochondrial protein-coding genes of large and can reach fixation. Here we investigate this phenomenon for a set of all 13 mitochondrial protein-coding genes from 110 mammalian species. By using body mass as a proxy for Ne, we show that large mammals (i

Sorenson, Michael

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