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Sample records for discordant monozygotic twins

  1. Monozygotic twins discordant for sex.

    PubMed Central

    Schmidt, R; Sobel, E H; Nitowsky, H M; Dar, H; Allen, F H

    1976-01-01

    A pair of monozygotic, adolescent twins is discordant for sex. The phenotypic female twin has chromosome constitution of 46, XY/45, X. She displays many signs of Turner's syndrome, including typical facies, webbed neck, malformed left kidney, high plasma gonadotropins, and streak ovaries. However, her height is 154 cm which exceeds the height usually reported in Turner's syndrome. The male twin has a karyotype of 46, XY and normal sexual development. Only two other reports of pairs of monozygotic twins of opposite sex have been published. Images PMID:944787

  2. Monozygotic twins discordant for trisomy 13.

    PubMed

    Ramsey, K Wong; Slavin, T P; Graham, G; Hirata, G I; Balaraman, V; Seaver, L H

    2012-04-01

    Monozygotic twins with discordant karyotypes are rare. We report a case of monozygotic twins discordant for trisomy 13 by amniocyte karyotypes. Ultrasound revealed multiple congenital anomalies in Twin A (47,XY,+13), none in Twin B (46,XY), and monochorionic-diamniotic placentation. Zygosity testing performed both prenatally and after birth supported monozygosity. Twin A died in the neontal period. Twin B survived and had normal physical examination, but peripheral blood karyotype revealed 20% mosaicism for trisomy 13. Monochorionic-diamniontic placentation with vascular anastomoses was confirmed by pathological examination. In this paper, we discuss the various mechanisms by which monozygotic twins may have discordant karyotypes. The surviving twin, structurally and developmentally normal at 6 months of age, will be monitored for potential complications of uniparental disomy of chromosome 13 and trisomy 13 mosaicism.

  3. Monozygotic twins with trisomy 18: a report of discordant phenotype.

    PubMed Central

    Schlessel, J S; Brown, W T; Lysikiewicz, A; Schiff, R; Zaslav, A L

    1990-01-01

    The predicted incidence of liveborn monozygotic trisomy 18 twins is one per million births. The first case of liveborn monozygotic trisomy 18 twins was reported in 1989 and we report a second case in which striking phenotypic discordance existed. The probability of monozygotic trisomy 18 twinning and the mechanisms for phenotypic discordance in trisomic twins is discussed. Images PMID:2246775

  4. Monozygotic twins discordant for Aicardi syndrome.

    PubMed Central

    Costa, T; Greer, W; Rysiecki, G; Buncic, J R; Ray, P N

    1997-01-01

    Aicardi syndrome is a developmental disorder characterised by agenesis of the corpus callosum, retinal lacunae, seizures, and developmental delay. It is believed to be X linked with lethality in males. We report a set of monozygotic female twins one of whom is healthy and intellectually normal while the other has the classical Aicardi phenotype with profound retardation. Family history is negative. Both had normal karyotypes. Monozygosity was established by blood grouping, chromosomal heteromorphisms, and DNA analysis using six hypervariable probes (five autosomal and one X linked) and three X linked RFLP probes. We tested the hypothesis that preferential inactivation of a different X chromosome had occurred in each girl. Methylation sensitive RFLP analysis of DNA from EBV transformed B lymphocytes and cultured skin fibroblasts using MspI/HpaII digestion and probing with M27 beta showed a very similar pattern of X inactivation in both twins with no evidence of preferential expression of one particular X chromosome. We conclude that the abnormalities in the affected twin are probably the consequence of a postzygotic mutation in early embryonic development. Images PMID:9279766

  5. Methylomic analysis of monozygotic twins discordant for childhood psychotic symptoms

    PubMed Central

    Fisher, Helen L; Murphy, Therese M; Arseneault, Louise; Caspi, Avshalom; Moffitt, Terrie E; Viana, Joana; Hannon, Eilis; Pidsley, Ruth; Burrage, Joe; Dempster, Emma L; Wong, Chloe C Y; Pariante, Carmine M; Mill, Jonathan

    2015-01-01

    Childhood psychotic symptoms are associated with increased rates of schizophrenia, other psychiatric disorders, and suicide attempts in adulthood; thus, elucidating early risk indicators is crucial to target prevention efforts. There is considerable discordance for psychotic symptoms between monozygotic twins, indicating that child-specific non-genetic factors must be involved. Epigenetic processes may constitute one of these factors and have not yet been investigated in relation to childhood psychotic symptoms. Therefore, this study explored whether differences in DNA methylation at age 10 were associated with monozygotic twin discordance for psychotic symptoms at age 12. The Environmental Risk (E-Risk) Longitudinal Twin Study cohort of 2,232 children (1,116 twin pairs) was assessed for age-12 psychotic symptoms and 24 monozygotic twin pairs discordant for symptoms were identified for methylomic comparison. Children provided buccal samples at ages 5 and 10. DNA was bisulfite modified and DNA methylation was quantified using the Infinium HumanMethylation450 array. Differentially methylated positions (DMPs) associated with psychotic symptoms were subsequently tested in post-mortem prefrontal cortex tissue from adult schizophrenia patients and age-matched controls. Site-specific DNA methylation differences were observed at age 10 between monozygotic twins discordant for age-12 psychotic symptoms. Similar DMPs were not found at age 5. The top-ranked psychosis-associated DMP (cg23933044), located in the promoter of the C5ORF42 gene, was also hypomethylated in post-mortem prefrontal cortex brain tissue from schizophrenia patients compared to unaffected controls. These data tentatively suggest that epigenetic variation in peripheral tissue is associated with childhood psychotic symptoms and may indicate susceptibility to schizophrenia and other mental health problems. PMID:26479702

  6. Hippocampal MRI volumetry in cognitively discordant monozygotic twin pairs

    PubMed Central

    Jarvenpaa, T; Laakso, M; Rossi, R; Koskenvuo, M; Kaprio, J; Raiha, I; Kurki, T; Laine, M; Frisoni, G; Rinne, J

    2004-01-01

    Objective: To investigate whether hippocampal atrophy, a proxy for incipient Alzheimer's disease, can be detected in non-demented monozygotic co-twins of demented twins by using volumetric magnetic resonance imaging (MRI). Methods: Seven pairs of monozygotic female twins discordant for cognitive function (mean (SD) age 75 (4) years), and 10 age and education matched healthy controls (seven women, three men; mean age 73 (3) years) were studied with volumetric MRI. Results: The mean normalised right hippocampal volume was 31% lower (p = 0.002) in the demented twins, and 6% lower (p = 0.45) in the non-demented twins than in the controls. In the left hippocampus, the mean normalised volume was 36% lower (p<0.001) in the demented twins, and 9% lower (p = 0.13) in the non-demented twins than in the controls. Conclusions: Significant hippocampal atrophy was detected in the demented twins compared with the controls. This is in line with previous imaging and pathological studies, with hippocampus showing the early changes in Alzheimer's disease. In the non-demented twins, only a minor, non-significant reduction was observed in the hippocampal volumes compared with the controls. This could reflect gene–environment interactions that have protected the non-demented twins longer than their demented co-twins and contributed to the relative preservation of their hippocampal volumes, or it could be a sign of preclinical Alzheimer's disease in the non-demented twins. PMID:14707319

  7. Genetic and epigenetic analysis of monozygotic twins discordant for testicular cancer.

    PubMed

    Kratz, Christian P; Edelman, Daniel C; Wang, Yonghong; Meltzer, Paul S; Greene, Mark H

    2014-01-01

    Despite the notion that monozygotic (identical) twins share 100% identical genetic information, genetic differences among monozygotic twin pairs do occur and can be explained by mechanisms occurring during post-zygotic events. Despite such twins being fundamentally "identical", these post-zygotic genetic changes may give rise to phenotypic differences and genetic diseases. Consequently, studies of monozygotic twin pairs discordant for specific genetic diseases represent an important tool for the identification of disease genes. We used array comparative genomic hybridization (aCGH) and methylation arrays to search for genetic and epigenetic differences in blood drawn from four monozygotic twin pairs discordant for testicular germ cell tumors. No consistent differences were identified. A larger twin study would be required to achieve confident discovery of very subtle differences between monozygotic twins discordant for testicular germ cell tumors. PMID:25379132

  8. Epigenetic differences in monozygotic twins discordant for major depressive disorder.

    PubMed

    Malki, K; Koritskaya, E; Harris, F; Bryson, K; Herbster, M; Tosto, M G

    2016-01-01

    Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability. In this study we explored epigenetic differences in peripheral blood samples in three MZ twin studies on major depressive disorder (MDD). Epigenetic data for twin pairs were collected as part of a previous study using 8.1-K-CpG microarrays tagging DNA modification in white blood cells from MZ twins discordant for MDD. Data originated from three geographical regions: UK, Australia and the Netherlands. Ninety-seven MZ pairs (194 individuals) discordant for MDD were included. Different methods to address non independently-and-identically distributed (non-i.i.d.) data were evaluated. Machine-learning methods with feature selection centered on support vector machine and random forest were used to build a classifier to predict cases and controls based on epivariations. The most informative variants were mapped to genes and carried forward for network analysis. A mixture approach using principal component analysis (PCA) and Bayes methods allowed to combine the three studies and to leverage the increased predictive power provided by the larger sample. A machine-learning algorithm with feature reduction classified affected from non-affected twins above chance levels in an independent training-testing design. Network analysis revealed gene networks centered on the PPAR-γ (NR1C3) and C-MYC gene hubs interacting through the AP-1 (c-Jun) transcription factor. PPAR-γ (NR1C3) is a drug target for pioglitazone, which has been shown to reduce depression symptoms in patients with MDD. Using a data-driven approach we were able to overcome challenges of non-i.i.d. data when combining epigenetic studies from MZ twins discordant for MDD. Individually, the studies yielded

  9. Epigenetic differences in monozygotic twins discordant for major depressive disorder

    PubMed Central

    Malki, K; Koritskaya, E; Harris, F; Bryson, K; Herbster, M; Tosto, M G

    2016-01-01

    Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability. In this study we explored epigenetic differences in peripheral blood samples in three MZ twin studies on major depressive disorder (MDD). Epigenetic data for twin pairs were collected as part of a previous study using 8.1-K-CpG microarrays tagging DNA modification in white blood cells from MZ twins discordant for MDD. Data originated from three geographical regions: UK, Australia and the Netherlands. Ninety-seven MZ pairs (194 individuals) discordant for MDD were included. Different methods to address non independently-and-identically distributed (non-i.i.d.) data were evaluated. Machine-learning methods with feature selection centered on support vector machine and random forest were used to build a classifier to predict cases and controls based on epivariations. The most informative variants were mapped to genes and carried forward for network analysis. A mixture approach using principal component analysis (PCA) and Bayes methods allowed to combine the three studies and to leverage the increased predictive power provided by the larger sample. A machine-learning algorithm with feature reduction classified affected from non-affected twins above chance levels in an independent training-testing design. Network analysis revealed gene networks centered on the PPAR−γ (NR1C3) and C-MYC gene hubs interacting through the AP-1 (c-Jun) transcription factor. PPAR−γ (NR1C3) is a drug target for pioglitazone, which has been shown to reduce depression symptoms in patients with MDD. Using a data-driven approach we were able to overcome challenges of non-i.i.d. data when combining epigenetic studies from MZ twins discordant for MDD. Individually, the studies

  10. Epigenetic differences in monozygotic twins discordant for major depressive disorder.

    PubMed

    Malki, K; Koritskaya, E; Harris, F; Bryson, K; Herbster, M; Tosto, M G

    2016-06-14

    Although monozygotic (MZ) twins share the majority of their genetic makeup, they can be phenotypically discordant on several traits and diseases. DNA methylation is an epigenetic mechanism that can be influenced by genetic, environmental and stochastic events and may have an important impact on individual variability. In this study we explored epigenetic differences in peripheral blood samples in three MZ twin studies on major depressive disorder (MDD). Epigenetic data for twin pairs were collected as part of a previous study using 8.1-K-CpG microarrays tagging DNA modification in white blood cells from MZ twins discordant for MDD. Data originated from three geographical regions: UK, Australia and the Netherlands. Ninety-seven MZ pairs (194 individuals) discordant for MDD were included. Different methods to address non independently-and-identically distributed (non-i.i.d.) data were evaluated. Machine-learning methods with feature selection centered on support vector machine and random forest were used to build a classifier to predict cases and controls based on epivariations. The most informative variants were mapped to genes and carried forward for network analysis. A mixture approach using principal component analysis (PCA) and Bayes methods allowed to combine the three studies and to leverage the increased predictive power provided by the larger sample. A machine-learning algorithm with feature reduction classified affected from non-affected twins above chance levels in an independent training-testing design. Network analysis revealed gene networks centered on the PPAR-γ (NR1C3) and C-MYC gene hubs interacting through the AP-1 (c-Jun) transcription factor. PPAR-γ (NR1C3) is a drug target for pioglitazone, which has been shown to reduce depression symptoms in patients with MDD. Using a data-driven approach we were able to overcome challenges of non-i.i.d. data when combining epigenetic studies from MZ twins discordant for MDD. Individually, the studies yielded

  11. Discordant phenotypes in monozygotic twins with identical de novo WT1 mutation.

    PubMed

    Yu, Zihua; Yang, Yonghui; Feng, Dongning

    2012-06-01

    Mutations in the WT1 gene, leading to Denys-Drash syndrome and Frasier syndrome, can also cause isolated steroid-resistant nephrotic syndrome (ISRNS). Previous studies have reported six pairs of monozygotic twins with WT1 mutations, including one presenting with discordant phenotypes with identical WT1 mutations being of paternal origin and five pairs of monozygotic twins presenting the same phenotype with identical WT1 mutations. In this study, we report on female monozygotic twins showing discordant phenotypes with an identical de novo WT1 mutation, R394W, and presenting incomplete Denys-Drash syndrome and ISRNS. PMID:26069768

  12. Monozygotic Twinning.

    PubMed

    Benirschke, Kurt

    2013-03-01

    This article discusses pathologies found in monozygotic twinning. Detailed information is provided regarding the development during monozygotic twin formation: embryo development, twin-to-twin transfusion syndrome, acardiac twinning, vanishing twins, conjoined twins, and Beckwith-Weidmann syndrome twins. An algorithm describing the approach for identifying pathology in a placenta with multiple pregnancies is presented.

  13. Monozygotic twin discordant for Down syndrome: mos 47,XX,+21/46,XX and 46,XX.

    PubMed

    Choi, Sun Ah; Ko, Jung Min; Shin, Choong Ho; Yang, Sei Won; Choi, Jin Sun; Oh, Sun Kyung

    2013-08-01

    Monozygotic twins, developed from a single zygote, are almost identical in clinical phenotype and concordant karyotypes. Monozygotic twins with discordant karyotypes are thought to be quite rare. Here, we report monochorionic-diamniotic twins discordant for Down syndrome. On findings of prenatal ultrasonography, nuchal translucency thickness was different between twins, and suggested that one of the twins was at high risk for having chromosomal abnormalities including Down syndrome. The twins were monochorionic-diamniotic; therefore, chorionic villi sampling of the common placenta was performed. The karyotype of the chorionic villi cells was 46,XX, and pregnancy was maintained. After delivery, dysmorphic clinical features suggesting Down syndrome were found in one of the twins, while the other twin showed a morphologically normal appearance. Karyotypes of peripheral blood leukocytes were repeatedly normal in the dysmorphic twin; however, the karyotype of skin fibroblasts from the dysmorphic twin indicated Down syndrome mosaicism; 47,XX,+21[99]/46,XX[2]. The karyotype of skin fibroblasts from the morphologically normal twin was 46,XX. Monozygosity of the twins was confirmed by a short tandem repeat analysis using 16 polymorphic markers. A mitotic nondisjunction followed by the twinning would explain the discordant karyotypes between monozygotic twins.

  14. Prenatal diagnosis and management of monozygotic twins discordant for turner syndrome.

    PubMed

    Gou, Chenyu; Gao, Yu; Chen, Baojiang; Fang, Qun

    2014-01-01

    Discordance for Turner syndrome in monozygotic (MZ) twins, which is known as heterokaryotypia, is very rare in MZ pregnancies. The combined effect of idiochromosome loss due to an anaphase lag and the relocation of discordant blastomeres may trigger the twinning procedure and discordance of Turner syndrome. We present 2 cases of MZ twins discordant for Turner syndrome that were diagnosed prenatally by ultrasound and cytogenetic studies (one fetus was 45,X and the other 46,XX). Both cases, which involved monochorionic (MC) diamniotic twins, underwent selective feticide and had favorable outcomes for the remaining twin. Ultrasound, amniocentesis of both sacs (dual amniocentesis) and zygosity determination are indispensable in diagnosing heterokaryotypia. Selective feticide is a treatment option in cases of heterokaryotypic MC diamniotic twins, and in our cases, it resulted in favorable outcomes for the remaining twin.

  15. Monozygotic twins discordant for intermittent allergic rhinitis differ in mRNA and protein levels.

    PubMed

    Sjogren, A-K M; Barrenas, F; Muraro, A; Gustafsson, M; Saetrom, P; Wang, H; Benson, M

    2012-06-01

    Monozygotic (MZ) twins discordant for complex diseases may help to find disease mechanisms that are not due to genetic variants. Intermittent allergic rhinitis (IAR) is an optimal disease model because it occurs at defined time points each year, owing to known external antigens. We hypothesized that MZ twins discordant for IAR could help to find gene expression differences that are not dependent on genetic variants. We collected blood outside of the season from MZ twins discordant for IAR, challenged their peripheral blood mononuclear cells (PBMC) with pollen allergen in vitro, collected supernatants and isolated CD4+ T cells. We identified disease-relevant mRNAs and proteins that differed between the discordant MZ twins. By contrast, no differences in microRNA expression were found. Our results indicate that MZ twins discordant for IAR is an optimal model to identify disease mechanisms that are not due to genetic variants. PMID:22515200

  16. Chromosome 22q11.2 microdeletion in monozygotic twins with discordant phenotype and deletion size.

    PubMed

    Halder, Ashutosh; Jain, Manish; Chaudhary, Isha; Varma, Binuja

    2012-01-01

    We report on a pair of male monozygotic twins with 22q11.2 microdeletion, discordant phenotype and discordant deletion size. The second twin had findings suggestive of DiGeorge syndrome, while the first twin had milder anomalies without any cardiac malformation. The second twin had presented with intractable convulsion, cyanosis and cardiovascular failure in the fourth week of life and expired on the sixth week of life, whereas the first twin had some characteristic facial appearance with developmental delay but no other signs of the 22q11.2 microdeletion syndrome including cardiovascular malformation. The fluorescence in situ hybridization (FISH) analysis had shown a microdeletion on the chromosome 22q11.2 in both twins. The interphase FISH did not find any evidence for the mosaicism. The genomic DNA microarray analysis, using HumanCytoSNP-12 BeadChip (Illumina), was identical between the twins except different size of deletion of 22q11.2. The zygosity using HumanCytoSNP-12 BeadChip (Illumina) microarray analysis suggested monozygosity. This observation indicates that altered size of the deletion may be the underlying etiology for the discordance in phenotype in monozygotic twins. We think early post zygotic events (mitotic non-allelic homologous recombination) could have been played a role in the alteration of 22q11.2 deletion size and, thus phenotypic variability in the monozygotic twins. PMID:22413934

  17. Is there a genetic basis for Fuchs' heterochromic uveitis? Discordance in monozygotic twins.

    PubMed Central

    Jones, N P; Read, A P

    1992-01-01

    One pair, and probably two pairs, of monozygotic twins are reported with discordance for Fuchs' heterochromic uveitis (FHU). Regular Mendelian inheritance of this disease is now proved to be impossible. The heritability of FHU is low and may be zero. The possibility of any genetic predisposition to the disease and its association with 'simple' heterochromia are discussed. Images PMID:1739686

  18. Discordant sex in monozygotic XXY/XX twins: a case report.

    PubMed

    Tachon, G; Lefort, G; Puechberty, J; Schneider, A; Jeandel, C; Boulot, P; Prodhomme, O; Meyer, P; Taviaux, S; Touitou, I; Pellestor, F; Geneviève, D; Gatinois, V

    2014-12-01

    We report a case of discordant phenotypic sex in monozygotic twins mosaic 47,XXY/46,XX: monozygotic heterokaryotypic twins. The twins presented with cognitive and comprehension delay, behavioural and language disorders, all symptoms frequently reported in Klinefelter syndrome. Molecular zygosity analysis with several markers confirmed that the twins are in effect monozygotic (MZ). Array comparative genomic hybridization found no evidence for the implication of copy number variation in the phenotypes. Ultrasound scans of the reproductive organs revealed no abnormalities. Endocrine tests showed a low testosterone level in Twin 1 (male phenotype) and a low gonadotrophin level in Twin 2 (female phenotype) which, combined with the results from ultrasound examination, provided useful information for potentially predicting the future fertility potential of the twins. Blood karyotypes revealed the presence of a normal 46,XX cell line and an aneuploïd 47,XXY cell line in both patients. Examination of the chromosome constitutions of various tissues such as blood, buccal smear and urinary sediment not surprisingly showed different proportions for the 46,XX and 47,XXY cell lines, which most likely explains the discordant phenotypic sex and mild Klinefelter features. The most plausible underlying biological mechanism is a post-zygotic loss of the Y chromosome in an initially 47,XXY zygote. This would result in an embryo with both 46,XX and 47,XXY cells lines which could subsequently divide into two monozygotic embryos through a twinning process. The two cell lines would then be distributed differently between tissues which could result in phenotypic discordances in the twins. These observations emphasize the importance of regular paediatric evaluations to determine the optimal timing for fertility preservation measures and to detect new Klinefelter features which could appear throughout childhood in the two subjects.

  19. Comparison of Genomic and Epigenomic Expression in Monozygotic Twins Discordant for Rett Syndrome.

    PubMed

    Miyake, Kunio; Yang, Chunshu; Minakuchi, Yohei; Ohori, Kenta; Soutome, Masaki; Hirasawa, Takae; Kazuki, Yasuhiro; Adachi, Noboru; Suzuki, Seiko; Itoh, Masayuki; Goto, Yu-Ichi; Andoh, Tomoko; Kurosawa, Hiroshi; Oshimura, Mitsuo; Sasaki, Masayuki; Toyoda, Atsushi; Kubota, Takeo

    2013-01-01

    Monozygotic (identical) twins have been widely used in genetic studies to determine the relative contributions of heredity and the environment in human diseases. Discordance in disease manifestation between affected monozygotic twins has been attributed to either environmental factors or different patterns of X chromosome inactivation (XCI). However, recent studies have identified genetic and epigenetic differences between monozygotic twins, thereby challenging the accepted experimental model for distinguishing the effects of nature and nurture. Here, we report the genomic and epigenomic sequences in skin fibroblasts of a discordant monozygotic twin pair with Rett syndrome, an X-linked neurodevelopmental disorder characterized by autistic features, epileptic seizures, gait ataxia and stereotypical hand movements. The twins shared the same de novo mutation in exon 4 of the MECP2 gene (G269AfsX288), which was paternal in origin and occurred during spermatogenesis. The XCI patterns in the twins did not differ in lymphocytes, skin fibroblasts, and hair cells (which originate from ectoderm as does neuronal tissue). No reproducible differences were detected between the twins in single nucleotide polymorphisms (SNPs), insertion-deletion polymorphisms (indels), or copy number variations. Differences in DNA methylation between the twins were detected in fibroblasts in the upstream regions of genes involved in brain function and skeletal tissues such as Mohawk Homeobox (MKX), Brain-type Creatine Kinase (CKB), and FYN Tyrosine Kinase Protooncogene (FYN). The level of methylation in these upstream regions was inversely correlated with the level of gene expression. Thus, differences in DNA methylation patterns likely underlie the discordance in Rett phenotypes between the twins. PMID:23805272

  20. Prenatal diagnosis of female monozygotic twins discordant for Turner syndrome: implications for prenatal genetic counselling.

    PubMed

    Gilbert, B; Yardin, C; Briault, S; Belin, V; Lienhardt, A; Aubard, Y; Battin, J; Servaud, M; Philippe, H J; Lacombe, D

    2002-08-01

    We describe a set of monozygotic (MZ) female twins, one of whom presented with a typical Turner syndrome (TS) phenotype and the other a normal female phenotype. Prenatal fetal ultrasonographic examination showed a monochorial diamniotic pregnancy with a hygroma colli and growth delay in Twin A and no anomalies in Twin B. Karyotypic analysis performed on fetal blood samples demonstrated a 46,XX/45,X (23/2) mosaicism in Twin A and a normal 46,XX chromosome constitution in Twin B. At birth, Twin A presented with a typical TS and Twin B had a normal female phenotype. Postnatal cytogenetic investigation of blood lymphocytes showed the same 46,XX/45,X mosaicism in both twins: 46,XX/45,X (40/7) in Twin A and 46,XX/45,X (40/5) in Twin B. Further investigations at the age of 10 months showed in Twin A a 46,XX/45,X (98/2) mosaicism in lymphocytes and 100% of 45,X (50 analysed cells) in fibroblasts, and in Twin B a normal 46,XX (100 analysed cells) chromosome constitution in lymphocytes but a mild 46,XX/45,X (78/2) mosaicism in fibroblasts. Monozygosity was confirmed by molecular analysis. To our knowledge, this is the first report of prenatal diagnosis of MZ female twins discordant for TS. Review of reported sets of MZ female twins (eight cases) or triplets (one case) discordant for TS shows, as in the present case, that the phenotype correlates better with the chromosomal distribution of mosaicism in fibroblasts than in lymphocytes. In the blood of MZ twins chimerism may modify the initial allocation of the mosaicism. These results suggest that, in cases of prenatal diagnosis of MZ female twins discordant for TS, the phenotype of each twin would be better predicted from karyotype analysis of cells from amniotic fluid than from fetal blood.

  1. Methylomic analysis of monozygotic twins discordant for autism spectrum disorder and related behavioural traits.

    PubMed

    Wong, C C Y; Meaburn, E L; Ronald, A; Price, T S; Jeffries, A R; Schalkwyk, L C; Plomin, R; Mill, J

    2014-04-01

    Autism spectrum disorder (ASD) defines a group of common, complex neurodevelopmental disorders. Although the aetiology of ASD has a strong genetic component, there is considerable monozygotic (MZ) twin discordance indicating a role for non-genetic factors. Because MZ twins share an identical DNA sequence, disease-discordant MZ twin pairs provide an ideal model for examining the contribution of environmentally driven epigenetic factors in disease. We performed a genome-wide analysis of DNA methylation in a sample of 50 MZ twin pairs (100 individuals) sampled from a representative population cohort that included twins discordant and concordant for ASD, ASD-associated traits and no autistic phenotype. Within-twin and between-group analyses identified numerous differentially methylated regions associated with ASD. In addition, we report significant correlations between DNA methylation and quantitatively measured autistic trait scores across our sample cohort. This study represents the first systematic epigenomic analyses of MZ twins discordant for ASD and implicates a role for altered DNA methylation in autism. PMID:23608919

  2. DNA Methylation Changes in the IGF1R Gene in Birth Weight Discordant Adult Monozygotic Twins.

    PubMed

    Tsai, Pei-Chien; Van Dongen, Jenny; Tan, Qihua; Willemsen, Gonneke; Christiansen, Lene; Boomsma, Dorret I; Spector, Tim D; Valdes, Ana M; Bell, Jordana T

    2015-12-01

    Low birth weight (LBW) can have an impact on health outcomes in later life, especially in relation to pre-disposition to metabolic disease. Several studies suggest that LBW resulting from restricted intrauterine growth leaves a footprint on DNA methylation in utero, and this influence likely persists into adulthood. To investigate this further, we performed epigenome-wide association analyses of blood DNA methylation using Infinium HumanMethylation450 BeadChip profiles in 71 adult monozygotic (MZ) twin pairs who were extremely discordant for birth weight. A signal mapping to the IGF1R gene (cg12562232, p = 2.62 × 10(-8)), was significantly associated with birth weight discordance at a genome-wide false-discovery rate (FDR) of 0.05. We pursued replication in three additional independent datasets of birth weight discordant MZ pairs and observed the same direction of association, but the results were not significant. However, a meta-analysis across the four independent samples, in total 216 birth-weight discordant MZ twin pairs, showed a significant positive association between birth weight and DNA methylation differences at IGF1R (random-effects meta-analysis p = .04), and the effect was particularly pronounced in older twins (random-effects meta-analysis p = .008, 98 older birth-weight discordant MZ twin pairs). The results suggest that severe intra-uterine growth differences (birth weight discordance >20%) are associated with methylation changes in the IGF1R gene in adulthood, independent of genetic effects.

  3. Attention Problems and Attention-Deficit/Hyperactivity Disorder in Discordant and Concordant Monozygotic Twins: Evidence of Environmental Mediators

    ERIC Educational Resources Information Center

    Lehn, Hanne; Derks, Eske M.; Hudziak, James J.; Heutink, Peter; van Beijsterveldt, Toos; Boomsma, Dorret I.

    2007-01-01

    Objective: To study familial and nonfamilial environmental influences on attention problems and attention-deficit/hyperactivity disorder (ADHD) in monozygotic twins discordant and concordant-high and low for these traits. Method: Ninety-five twin pairs from The Netherlands Twin Register were selected. Longitudinal survey data were collected at 1,…

  4. The road not taken: life experiences in monozygotic twin pairs discordant for major depression

    PubMed Central

    Kendler, KS; Halberstadt, LJ

    2012-01-01

    In an effort to understand how environmental experiences contribute to risk for major depression (MD), we conducted joint autobiographical interviews with 14 pairs of monozygotic twins (mean age 51.2) rigorously discordant for a lifetime history of MD. Twelve of the pairs could be sorted into four broad categories. In two pairs, discordance was associated with a single traumatic event occurring to the affected twin. In seven pairs, the well twin had one stable, long-term, successful romantic relationship, whereas the affected co-twin had romantic reversals one or more of which precipitated depressive episodes. These pairs varied in the degree to which the romantic problems seemed to arise from bad luck or poor choices. In one pair, occupational difficulties were strongly related to discordance in experiences with MD. In two pairs, several mechanisms seemed to be at work. Discordance in the quality of intimate love relationships was the most common etiological factor revealed by interview in these discordant pairs, with single dramatic events and occupational problems being considerably rarer. Even in this best of natural experiments, the causal interrelationship between personality, environment and depressive episodes was not always clear. Many pairs illustrated the protective effects of planfulness and the malignant effect of cumulative continuity where early difficulties in relationships shaped the subsequent life course. These results speak both to the importance of environmental influences on human well-being and psychopathology, and the complexity of the causal paths underlying their effects. PMID:22641178

  5. Integration of DNA sequence and DNA methylation changes in monozygotic twin pairs discordant for schizophrenia.

    PubMed

    Castellani, C A; Melka, M G; Gui, J L; O'Reilly, R L; Singh, S M

    2015-12-01

    Schizophrenia is a complex mental disorder with high heritability (80%), extensive genetic heterogeneity, environmental contributions and only 50% concordance in discordant monozygotic (MZ) twins. Discordant MZ twins provide an exceptional opportunity to assess patient specific genome-wide genetic and epigenetic changes that may account for the disease phenotype. A combined analysis of genetic and epigenetic changes on the same twin pairs is expected to provide a more effective approach for two reasons. First, it is now possible to generate relatively reliable complete genome sequences as well as promoter methylation states on an individual level and second, the unaffected twin that originated from the same zygote provides a near perfect genetic match for contrast and comparison. This report deals with the combined analysis of DNA sequence data and methylation data on two pairs of discordant MZ twins that have been clinically followed for over 20 years. Results on Family 1 show that 58 genes differ in DNA sequence as well as promoter methylation in a schizophrenia-affected twin as compared to her healthy co-twin. The corresponding number for family 2 was 13. The two lists are over represented by neuronal genes and include a number of known schizophrenia candidate genes and drug targets. The results argue that changes in multiple genes via co-localized genetic and epigenetic alteration contribute to a liability threshold that is necessary for development of schizophrenia. This novel hypothesis, although logical, remains to be validated.

  6. What monozygotic twins discordant for phenotype illustrate about mechanisms influencing genetic forms of neurodegeneration.

    PubMed

    Ketelaar, M E; Hofstra, E M W; Hayden, M R

    2012-04-01

    As monozygotic (MZ) twins are believed to be genetically identical, discordance for disease phenotype between MZ twins has been used in genetic research to understand the contribution of genetic vs environmental factors in disease development. However, recent studies show that MZ twins can differ both genetically and epigenetically. Screening MZ twins for genetic and/or epigenetic differences could be a useful and novel approach to identify modifying factors influencing phenotypic expression of disease. MZ twins that are phenotypically discordant for monogenic diseases are of special interest. Such occurrences have been described for Huntington's disease, spinocerebellar ataxias, as well as for familial forms of Alzheimer's disease. By comparing MZ twins that are phenotypically discordant, crucial factors influencing the phenotypic expression of the disease could be identified, which may be of relevance for understanding disease pathogenesis and variability in disease phenotype. Overall, understanding the crucial factors in development of a neurodegenerative disorder will have relevance for predictive testing, preventive treatment and could help to identify novel therapeutic targets. PMID:21981075

  7. Monozygotic twins discordant for constitutive BRCA1 promoter methylation, childhood cancer and secondary cancer.

    PubMed

    Galetzka, Danuta; Hansmann, Tamara; El Hajj, Nady; Weis, Eva; Irmscher, Benjamin; Ludwig, Marco; Schneider-Rätzke, Brigitte; Kohlschmidt, Nicolai; Beyer, Vera; Bartsch, Oliver; Zechner, Ulrich; Spix, Claudia; Haaf, Thomas

    2012-01-01

    We describe monozygotic twins discordant for childhood leukemia and secondary thyroid carcinoma. We used bisulfite pyrosequencing to compare the constitutive promoter methylation of BRCA1 and several other tumor suppressor genes in primary fibroblasts. The affected twin displayed an increased BRCA1 methylation (12%), compared with her sister (3%). Subsequent bisulfite plasmid sequencing demonstrated that 13% (6 of 47) BRCA1 alleles were fully methylated in the affected twin, whereas her sister displayed only single CpG errors without functional implications. This between-twin methylation difference was also found in irradiated fibroblasts and untreated saliva cells. The BRCA1 epimutation may have originated by an early somatic event in the affected twin: approximately 25% of her body cells derived from different embryonic cell lineages carry one epigenetically inactivated BRCA1 allele. This epimutation was associated with reduced basal protein levels and a higher induction of BRCA1 after DNA damage. In addition, we performed a genome-wide microarray analysis of both sisters and found several copy number variations, i.e., heterozygous deletion and reduced expression of the RSPO3 gene in the affected twin. This monozygotic twin pair represents an impressive example of epigenetic somatic mosaicism, suggesting a role for constitutive epimutations, maybe along with de novo genetic alterations in recurrent tumor development.

  8. Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences

    PubMed Central

    2012-01-01

    Genetic-epidemiological studies on monozygotic (MZ) twins have been used for decades to tease out the relative contributions of genes and the environment to a trait. Phenotypic discordance in MZ twins has traditionally been ascribed to non-shared environmental factors acting after birth, however recent data indicate that this explanation is far too simple. In this paper, we review other reasons for discordance, including differences in the in utero environment, genetic mosaicism, and stochastic factors, focusing particularly on epigenetic discordance. Epigenetic differences are gaining increasing recognition. Although it is clear that in specific cases epigenetic alterations provide a causal factor in disease etiology, the overall significance of epigenetics in twin discordance remains unclear. It is also challenging to determine the causality and relative contributions of environmental, genetic, and stochastic factors to epigenetic variability. Epigenomic profiling studies have recently shed more light on the dynamics of temporal methylation change and methylome heritability, yet have not given a definite answer regarding their relevance to disease, because of limitations in establishing causality. Here, we explore the subject of epigenetics as another component in human phenotypic variability and its links to disease focusing particularly on evidence from MZ twin studies. PMID:22898292

  9. A Discordant Monozygotic Twin Design Shows Blunted Cortisol Reactivity Among Bullied Children

    PubMed Central

    Ouellet-Morin, Isabelle; Danese, Andrea; Bowes, Lucy; Shakoor, Sania; Ambler, Antony; Pariante, Carmine M.; Papadopoulos, Andrew S.; Caspi, Avshalom; Moffitt, Terrie E.; Arseneault, Louise

    2013-01-01

    Objective Childhood adverse experiences are known to engender persistent changes in stress-related systems and brain structures involved in mood, cognition, and behavior in animal models. Uncertainty remains about the causal effect of early stressful experiences on physiological response to stress in human beings, as the impact of these experiences has rarely been investigated while controlling for both genetic and shared environmental influences. Method We tested whether bullying victimization, a repeated adverse experience in childhood, influences cortisol responses to a psychosocial stress test (PST) using a discordant monozygotic (MZ) twin design. Thirty pairs (43.3% males) of 12-year-old MZ twins discordant for bullying victimization were identified in the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative 1994–1995 cohort of families with twins. Results Bullied and nonbullied MZ twins showed distinct patterns of cortisol secretion after the PST. Specifically, bullied twins exhibited a blunted cortisol response compared with their nonbullied MZ co-twins, who showed the expected increase. This difference in cortisol response to stress could not be attributed to children's genetic makeup, their familial environments, pre-existing and concomitant individual factors, or the perception of stress and emotional response to the PST. Conclusion Results from this natural experiment provide support for a causal effect of adverse childhood experiences on the neuroendocrine response to stress. PMID:21621141

  10. Intra-Monozygotic Twin Pair Discordance and Longitudinal Variation of Whole-Genome Scale DNA Methylation in Adults

    PubMed Central

    Zhang, Su-Hua; Chen, Jinzhong; Lu, Daru; Shen, Min; Li, Chengtao

    2015-01-01

    Monozygotic twins share identical genomic DNA and are indistinguishable using conventional genetic markers. Increasing evidence indicates that monozygotic twins are epigenetically distinct, suggesting that a comparison between DNA methylation patterns might be useful to approach this forensic problem. However, the extent of epigenetic discordance between healthy adult monozygotic twins and the stability of CpG loci within the same individual over a short time span at the whole-genome scale are not well understood. Here, we used Infinium HumanMethylation450 Beadchips to compare DNA methylation profiles using blood collected from 10 pairs of monozygotic twins and 8 individuals sampled at 0, 3, 6, and 9 months. Using an effective and unbiased method for calling differentially methylated (DM) CpG sites, we showed that 0.087%–1.530% of the CpG sites exhibit differential methylation in monozygotic twin pairs. We further demonstrated that, on whole-genome level, there has been no significant epigenetic drift within the same individuals for up to 9 months, including one monozygotic twin pair. However, we did identify a subset of CpG sites that vary in DNA methylation over the 9-month period. The magnitude of the intra-pair or longitudinal methylation discordance of the CpG sites inside the CpG islands is greater than those outside the CpG islands. The CpG sites located on shores appear to be more suitable for distinguishing between MZ twins. PMID:26248206

  11. Intra-Monozygotic Twin Pair Discordance and Longitudinal Variation of Whole-Genome Scale DNA Methylation in Adults.

    PubMed

    Zhang, Na; Zhao, Shumin; Zhang, Su-Hua; Chen, Jinzhong; Lu, Daru; Shen, Min; Li, Chengtao

    2015-01-01

    Monozygotic twins share identical genomic DNA and are indistinguishable using conventional genetic markers. Increasing evidence indicates that monozygotic twins are epigenetically distinct, suggesting that a comparison between DNA methylation patterns might be useful to approach this forensic problem. However, the extent of epigenetic discordance between healthy adult monozygotic twins and the stability of CpG loci within the same individual over a short time span at the whole-genome scale are not well understood. Here, we used Infinium HumanMethylation450 Beadchips to compare DNA methylation profiles using blood collected from 10 pairs of monozygotic twins and 8 individuals sampled at 0, 3, 6, and 9 months. Using an effective and unbiased method for calling differentially methylated (DM) CpG sites, we showed that 0.087%-1.530% of the CpG sites exhibit differential methylation in monozygotic twin pairs. We further demonstrated that, on whole-genome level, there has been no significant epigenetic drift within the same individuals for up to 9 months, including one monozygotic twin pair. However, we did identify a subset of CpG sites that vary in DNA methylation over the 9-month period. The magnitude of the intra-pair or longitudinal methylation discordance of the CpG sites inside the CpG islands is greater than those outside the CpG islands. The CpG sites located on shores appear to be more suitable for distinguishing between MZ twins. PMID:26248206

  12. Mitochondrial DNA Variation and Heteroplasmy in Monozygotic Twins Clinically Discordant for Multiple Sclerosis.

    PubMed

    Souren, Nicole Y P; Gerdes, Lisa A; Kümpfel, Tania; Lutsik, Pavlo; Klopstock, Thomas; Hohlfeld, Reinhard; Walter, Jörn

    2016-08-01

    We examined the debated link between mitochondrial DNA (mtDNA) variation and multiple sclerosis (MS) using 49 monozygotic (MZ) twin pairs clinically discordant for MS, which enables to associate de novo mtDNA variants, skewed heteroplasmy, and mtDNA copy number with MS manifestation. Ultra-deep sequencing of blood-derived mtDNA revealed 25 heteroplasmic variants with potentially pathogenic features in 18 pairs. All variants were pair-specific and had low and/or similar heteroplasmy levels in both cotwins. In one pair, a confirmed pathogenic variant (m.11778G>A, heteroplasmy ∼50%) associated with Leber hereditary optic neuropathy was detected. Detailed diagnostic investigation revealed subclinical MS signs in the prior nondiseased cotwin. Moreover, neither mtDNA deletions nor copy-number variations were involved. Furthermore, the majority of heteroplasmic variants were shared among MZ twins and exhibited more similar heteroplasmy levels in the same tissue of MZ twins as compared with different tissues of the same individual. Heteroplasmy levels were also more similar within MZ twins compared with nonidentical siblings. Our analysis excludes mtDNA variation as a major driver of the discordant clinical manifestation of MS in MZ twins, and provides valuable insights into the occurrence and distribution of heteroplasmic variants within MZ twins and nonidentical siblings, and across different tissues. PMID:27119776

  13. Novel epigenetic changes unveiled by monozygotic twins discordant for smoking habits.

    PubMed

    Allione, Alessandra; Marcon, Francesca; Fiorito, Giovanni; Guarrera, Simonetta; Siniscalchi, Ester; Zijno, Andrea; Crebelli, Riccardo; Matullo, Giuseppe

    2015-01-01

    Exposure to cigarette smoking affects the epigenome and could increase the risk of developing diseases such as cancer and cardiovascular disorders. Changes in DNA methylation associated with smoking may help to identify molecular pathways that contribute to disease etiology. Previous studies are not completely concordant in the identification of differentially methylated regions in the DNA of smokers. We performed an epigenome-wide DNA methylation study in a group of monozygotic (MZ) twins discordant for smoking habits to determine the effect of smoking on DNA methylation. As MZ twins are considered genetically identical, this model allowed us to identify smoking-related DNA methylation changes independent from genetic components. We investigated the whole blood genome-wide DNA methylation profiles in 20 MZ twin pairs discordant for smoking habits by using the Illumina HumanMethylation450 BeadChip. We identified 22 CpG sites that were differentially methylated between smoker and non-smoker MZ twins by intra-pair analysis. We confirmed eight loci already described by other groups, located in AHRR, F2RL3, MYOG1 genes, at 2q37.1 and 6p21.33 regions, and also identified several new loci. Moreover, pathway analysis showed an enrichment of genes involved in GTPase regulatory activity. Our study confirmed the evidence of smoking-related DNA methylation changes, emphasizing that well-designed MZ twin models can aid the discovery of novel DNA methylation signals, even in a limited sample population. PMID:26043106

  14. Discordant Growth of Monozygotic Twins Starts at the Blastocyst Stage: A Case Study

    PubMed Central

    Noli, Laila; Capalbo, Antonio; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2015-01-01

    Summary Discordant growth is a common complication of monochorionic/diamniotic pregnancies; in approximately 50% of cases, the cause is unknown. The case presented here suggests that discordant growth of monozygotic twins could start during preimplantation development. Two inner cell masses (ICMs) within the same blastocyst may originate in uneven splitting of a single “parental” ICM, or the two ICMs may be formed independently de novo. We studied the transcriptomes of two morphologically distinct ICMs within a single blastocyst using high-resolution RNA sequencing. The data indicated that the two ICM were at different stages of development; one was in the earliest stages of lineage commitment, while the other had already differentiated into epiblast and primitive endoderm. IGF1-mediated signaling is likely to play a key role in ICM growth and to be the major driver behind these differences. PMID:26584541

  15. Discordant Growth of Monozygotic Twins Starts at the Blastocyst Stage: A Case Study.

    PubMed

    Noli, Laila; Capalbo, Antonio; Ogilvie, Caroline; Khalaf, Yacoub; Ilic, Dusko

    2015-12-01

    Discordant growth is a common complication of monochorionic/diamniotic pregnancies; in approximately 50% of cases, the cause is unknown. The case presented here suggests that discordant growth of monozygotic twins could start during preimplantation development. Two inner cell masses (ICMs) within the same blastocyst may originate in uneven splitting of a single "parental" ICM, or the two ICMs may be formed independently de novo. We studied the transcriptomes of two morphologically distinct ICMs within a single blastocyst using high-resolution RNA sequencing. The data indicated that the two ICM were at different stages of development; one was in the earliest stages of lineage commitment, while the other had already differentiated into epiblast and primitive endoderm. IGF1-mediated signaling is likely to play a key role in ICM growth and to be the major driver behind these differences.

  16. Hypermethylation of serotonin transporter gene in bipolar disorder detected by epigenome analysis of discordant monozygotic twins.

    PubMed

    Sugawara, H; Iwamoto, K; Bundo, M; Ueda, J; Miyauchi, T; Komori, A; Kazuno, A; Adati, N; Kusumi, I; Okazaki, Y; Ishigooka, J; Kojima, T; Kato, T

    2011-01-01

    Bipolar disorder (BD) is a severe mental disorder characterized by recurrent episodes of mania and depression. Serotonin transporter (HTT) is a target of antidepressants and is one of the strongest candidate molecules of mood disorder, however, genetic study showed equivocal results. Here, we performed promoter-wide DNA methylation analysis of lymphoblastoid cell lines (LCLs) derived from two pairs of monozygotic twins discordant for BD. To rule out the possible discordance of copy number variation (CNV) between twins, we performed CNV analysis and found the copy number profiles were nearly identical between the twin pairs except for immunoglobulin-related regions. Among the three genes we obtained as candidate regions showing distinct difference of DNA methylation between one of the two pairs, hypermethylation of SLC6A4, encoding HTT, in the bipolar twin was only confirmed by bisulfite sequencing. Then, promoter hypermethylation of SLC6A4 in LCLs of BD patients was confirmed in a case-control analysis. DNA methylation of SLC6A4 was significantly correlated with its mRNA expression level in individuals with the S/S genotype of HTTLPR, and mRNA expression level was lower in BD patients carrying the S/S genotype. Finally, DNA methylation of the same site was also higher in the postmortem brains of BD patients. This is the first study to report the role of epigenetic modification of SLC6A4 in BD using an unbiased approach, which provides an insight for its pathophysiology. PMID:22832526

  17. Hypomethylation within gene promoter regions and type 1 diabetes in discordant monozygotic twins.

    PubMed

    Elboudwarej, Emon; Cole, Michael; Briggs, Farren B S; Fouts, Alexandra; Fain, Pamela R; Quach, Hong; Quach, Diana; Sinclair, Elizabeth; Criswell, Lindsey A; Lane, Julie A; Steck, Andrea K; Barcellos, Lisa F; Noble, Janelle A

    2016-04-01

    Genetic susceptibility to type 1 diabetes (T1D) is well supported by epidemiologic evidence; however, disease risk cannot be entirely explained by established genetic variants identified so far. This study addresses the question of whether epigenetic modification of the inherited DNA sequence may contribute to T1D susceptibility. Using the Infinium HumanMethylation450 BeadChip array (450k), a total of seven long-term disease-discordant monozygotic (MZ) twin pairs and five pairs of HLA-identical, disease-discordant non-twin siblings (NTS) were examined for associations between DNA methylation (DNAm) and T1D. Strong evidence for global hypomethylation of CpG sites within promoter regions in MZ twins with TID compared to twins without T1D was observed. DNA methylation data were then grouped into three categories of CpG sites for further analysis, including those within: 1) the major histocompatibility complex (MHC) region, 2) non-MHC genes with reported T1D association through genome wide association studies (GWAS), and 3) the epigenome, or remainder of sites that did not include MHC and T1D associated genes. Initial results showed modest methylation differences between discordant MZ twins for the MHC region and T1D-associated CpG sites, BACH2, INS-IGF2, and CLEC16A (DNAm difference range: 2.2%-5.0%). In the epigenome CpG set, the greatest methylation differences were observed in MAGI2, FANCC, and PCDHB16, (DNAm difference range: 6.9%-16.1%). These findings were not observed in the HLA-identical NTS pairs. Targeted pyrosequencing of five candidate CpG loci identified using the 450k array in the original discordant MZ twins produced similar results using control DNA samples, indicating strong agreement between the two DNA methylation profiling platforms. However, findings for the top five candidate CpG loci were not replicated in six additional T1D-discordant MZ twin pairs. Our results indicate global DNA hypomethylation within gene promoter regions may contribute to T

  18. Epigenome-Wide DNA Methylation Analysis of Monozygotic Twins Discordant for Diurnal Preference.

    PubMed

    Wong, Chloe C Y; Parsons, Michael J; Lester, Kathryn J; Burrage, Joe; Eley, Thalia C; Mill, Jonathan; Dempster, Emma L; Gregory, Alice M

    2015-12-01

    Diurnal preference is an individual's preference for daily activities and sleep timing and is strongly correlated with the underlying circadian clock and the sleep-wake cycle validating its use as an indirect circadian measure in humans. Recent research has implicated DNA methylation as a mechanism involved in the regulation of the circadian clock system in humans and other mammals. In order to evaluate the extent of epigenetic differences associated with diurnal preference, we examined genome-wide patterns of DNA methylation in DNA from monozygotic (MZ) twin-pairs discordant for diurnal preference. MZ twins were selected from a longitudinal twin study designed to investigate the interplay of genetic and environmental factors in the development of emotional and behavioral difficulties. Fifteen pairs of MZ twins were identified in which one member scored considerably higher on the Horne-Ostberg Morningness-Eveningness Questionnaire (MEQ) than the other. Genome-wide DNA methylation patterns were assessed in twins' buccal cell DNA using the Illumina Infinium HumanMethylation450 BeadChips. Quality control and data pre-processing was undertaken using the wateRmelon package. Differentially methylated probes (DMPs) were identified using an analysis strategy taking into account both the significance and the magnitude of DNA methylation differences. Our data indicate that DNA methylation differences are detectable in MZ twins discordant for diurnal preference. Moreover, downstream gene ontology (GO) enrichment analysis on the top-ranked diurnal preference associated DMPs revealed significant enrichment of pathways that have been previously associated with circadian rhythm regulation, including cell adhesion processes and calcium ion binding.

  19. Progression in substance use initiation: A multilevel discordant monozygotic twin design.

    PubMed

    Richmond-Rakerd, Leah S; Slutske, Wendy S; Deutsch, Arielle R; Lynskey, Michael T; Agrawal, Arpana; Madden, Pamela A F; Bucholz, Kathleen K; Heath, Andrew C; Martin, Nicholas G

    2015-08-01

    Considerable attention has been paid to the "gateway" pattern of drug use initiation in which individuals progress from tobacco and alcohol use to cannabis and other illicit drugs. The extent to which this sequence reflects a causal impact of licit substance use on illicit substance involvement remains unclear. Clarifying the mechanisms underlying substance use initiation may help inform our understanding of risk for psychopathology, as increasing research is demonstrating associations between initiation patterns and heavier involvement. This study examined patterns of substance use initiation using a discordant twin design. Participants were 3,476 monozygotic twins (37% male) from the Australian Twin Registry who reported on their ages of tobacco, alcohol, and cannabis initiation. Multilevel proportional hazard regression models were used to (a) estimate within-twin-pair and between-twin-pair contributions to associations between the ages of onset of different drugs; and (b) examine whether the magnitude of effects differed as a function of the order of substance use initiation. Finding significant effects within twin pairs would support the hypothesis that the age of initiation of a substance causally influences the age of initiation of a subsequent substance. Finding significant effects between twin pairs would support the operation of familial influences that explain variation in the ages of initiation of multiple drugs. Within-twin-pair effects for typical patterns were modest. When initiation was atypical, however, larger within-twin-pair effects were observed and causal influences were more strongly implicated. Results support the utility of examining the timing and ordering of substance use initiation within sophisticated, genetically informative designs. PMID:26098047

  20. Progression in Substance Use Initiation: A Multilevel Discordant Monozygotic Twin Design

    PubMed Central

    Richmond-Rakerd, Leah S.; Slutske, Wendy S.; Deutsch, Arielle R.; Lynskey, Michael T.; Agrawal, Arpana; Madden, Pamela A.F.; Bucholz, Kathleen K.; Heath, Andrew C.; Martin, Nicholas G.

    2015-01-01

    Considerable attention has been paid to the “gateway” pattern of drug use initiation in which individuals progress from tobacco and alcohol use to cannabis and other illicit drugs. The extent to which this sequence reflects a causal impact of licit substance use on illicit substance involvement remains unclear. Clarifying the mechanisms underlying substance use initiation may help inform our understanding of risk for psychopathology, as increasing research is demonstrating associations between initiation patterns and heavier involvement. This study examined patterns of substance use initiation using a discordant twin design. Participants were 3,476 monozygotic twins (37% male) from the Australian Twin Registry who reported on their ages of tobacco, alcohol, and cannabis initiation. Multilevel proportional hazard regression models were employed to (a) estimate within-twin-pair and between-twin-pair contributions to associations between the ages of onset of different drugs; and (b) examine whether the magnitude of effects differed as a function of the order of substance use initiation. Finding significant effects within twin pairs would support the hypothesis that the age of initiation of one substance causally influences the age of initiation of a subsequent substance. Finding significant effects between twin pairs would support the operation of familial influences that explain variation in the ages of initiation of multiple drugs. Within-twin-pair effects for typical patterns were modest. When initiation was atypical, however, larger within-twin-pair effects were observed and causal influences were more strongly implicated. Results support the utility of examining the timing and ordering of substance use initiation within sophisticated, genetically informative designs. PMID:26098047

  1. Differences in psychomotor reaction time in male monozygotic twins discordant for lifetime cigarette smoking.

    PubMed

    Gibbons, L E; Simonen, R L; Videman, T; Battié, M C

    1996-12-01

    The effects of long-term cigarette smoking on psychomotor reaction time were investigated among 8 pairs of monozygotic male twins highly discordant for lifetime smoking (means 32.4 versus 0.6 pack-years). The men had no diagnosed cardiovascular disease or other major diseases, musculoskeletal complaints, or vision problems that might interfere with reaction time testing. The twins had similar education, work, and exercise histories; alcohol and coffee consumption and exposure to solvents were examined as possible confounds. Direct comparison of cotwins also controlled for age, genetics, and possible early environmental factors. Simple and choice reaction time were measured in the dominant hand and in both feet. The decision-time component of total reaction time was of primary interest. On average, long-term smokers had slower decision times than their nonsmoking twins; however, the differences were small (5 to 14%) and were not statistically significant for four of the six decision-time measures, perhaps due to the lack of power with only eight twin pairs. Further study may confirm our evidence suggesting that long-term cigarette smoking impedes reaction time, a key measure of function of the central nervous system.

  2. Maternal Hypomethylation of KvDMR in a Monozygotic Male Twin Pair Discordant for Beckwith-Wiedemann Syndrome.

    PubMed

    Elalaoui, S C; Garin, I; Sefiani, A; Perez de Nanclares, G

    2014-01-01

    Beckwith-Wiedemann syndrome (BWS; OMIM 130650) is a heterogeneous overgrowth syndrome characterized by visceromegaly, macroglossia, tumor predisposition, and other congenital abnormalities. BWS is usually associated with abnormalities of chromosome 11p15, including (epi)genetic changes, paternal disomy and point mutations. A number of identical twin pairs, mostly female, have been reported to be clinically discordant for BWS. Studies of monozygotic twins discordant for BWS provide more information about failure in the DNA methylation maintenance machinery during very early embryonic development. Here, we report a case of monozygotic male twins discordant for BWS phenotype. Methylation analysis of the 2 imprinted domains at 11p15.5 (H19DMR and KvDMR) was performed by methylation-specific MLPA and pyrosequencing of DNA extracted from peripheral blood and buccal swabs of both twins. Hypomethylation at KvDMR was identified in both cell types of the affected twin, whereas his healthy brother presented hypomethylation only in blood cells and a normal methylation profile in buccal swab. For diagnostic purposes, it is important to remember that twins can share fetal circulation and possibly share hematopoietic stem cells early in development; therefore, the affected and unaffected twins can share an epigenotype that will resemble partial hypomethylation. If a patient is a twin, it is valuable to obtain a sample from a tissue other than blood. PMID:24550765

  3. Genome, Epigenome and RNA sequences of Monozygotic Twins Discordant for Multiple Sclerosis

    SciTech Connect

    Miller, Neil

    2010-06-02

    Neil Miller, Deputy Director of Software Engineering at the National Center for Genome Resources, discusses a monozygotic twin study on June 2, 2010 at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  4. Anophthalmia-esophageal atresia syndrome caused by an SOX2 gene deletion in monozygotic twin brothers with markedly discordant phenotypes.

    PubMed

    Zenteno, Juan Carlos; Perez-Cano, Hector J; Aguinaga, Monica

    2006-09-15

    The clinical combination of anophthalmia/microphthalmia and esophageal atresia was first recognized in 1988 as a distinct variable multi-system malformation syndrome and since then at least 17 cases of the disease have been described, all of them sporadic in occurrence. We report a heterozygous SOX2 gene mutation underlying the syndrome of anophthalmia/microphthalmia-esophageal atresia and demonstrate that this entity can be associated to considerable clinical variability as shown by the discordant ocular phenotype observed in monozygotic twin brothers carrying an SOX2 deletion. This is the first report describing a strikingly discordant eye phenotype in monozygotic twins with the condition, with one of our patients being the first reported individual carrying an SOX2 lesion associated with unilateral eye defect. We discuss the probable sources for this remarkable phenotypic heterogeneity of the anophthalmia/microphthalmia syndrome in individuals with an identical genetic constitution.

  5. Discordant tooth agenesis and peg-shaped in a pair of monozygotic twins: Clinical and molecular study

    PubMed Central

    Antunes, Lívia Azeredo Alves; Küchler, Erika Calvano; Costa, Marcelo de Castro; Antunes, Leonardo Santos; Granjeiro, José Mauro

    2013-01-01

    The present report aimed to study an uncommon case of a pair of twins that presented a discordant dental phenotype. Family investigation, clinical, radiographic examination and molecular analysis were performed in both girls. Molecular analysis confirmed the monozygosity by deoxyribonucleic acid chip technology. One twin presented tooth agenesis in left upper lateral incisor and peg-shaped on the contra lateral side while the other twin had no dental alterations. The dental casts study employed digital caliper to compare morphological dimensions and showed alteration only in peg-shaped tooth. In conclusion, this study provide support that one or more mutated gene could cause discordances in dental phenotype in these monozygotic twins. PMID:24379875

  6. Copy number detection in discordant monozygotic twins of Congenital Diaphragmatic Hernia (CDH) and Esophageal Atresia (EA) cohorts.

    PubMed

    Veenma, Danielle; Brosens, Erwin; de Jong, Elisabeth; van de Ven, Cees; Meeussen, Connie; Cohen-Overbeek, Titia; Boter, Marjan; Eussen, Hubertus; Douben, Hannie; Tibboel, Dick; de Klein, Annelies

    2012-03-01

    The occurrence of phenotypic differences between monozygotic (MZ) twins is commonly attributed to environmental factors, assuming that MZ twins have a complete identical genetic make-up. Yet, recently several lines of evidence showed that both genetic and epigenetic factors could have a role in phenotypic discordance after all. A high occurrence of copy number variation (CNV) differences was observed within MZ twin pairs discordant for Parkinson's disease, thereby stressing on the importance of post-zygotic mutations as disease-predisposing events. In this study, the prevalence of discrepant CNVs was analyzed in discordant MZ twins of the Esophageal Atresia (EA) and Congenital Diaphragmatic Hernia (CDH) cohort in the Netherlands. Blood-derived DNA from 11 pairs (7 EA and 4 CDH) was screened using high-resolution SNP arrays. Results showed an identical copy number profile in each twin pair. Mosaic chromosome gain or losses could not be detected either with a detection threshold of 20%. Some of the germ-line structural events demonstrated in five out of eleven twin pairs could function as a susceptible genetic background. For example, the 177-Kb loss of chromosome 10q26 in CDH pair-3 harbors the TCF7L2 gene (Tcf4 protein), which is implicated in the regulation of muscle fiber type development and maturation. In conclusion, discrepant CNVs are not a common cause of twin discordancy in these investigated congenital anomaly cohorts. PMID:22071887

  7. A pair of monozygotic twins discordant for homosexuality: sex-dimorphic behavior and penile volume responses.

    PubMed

    McConaghy, N; Blaszczynski, A

    1980-04-01

    In reports of identical twins discordant for homosexuality, the homosexual twins showed the effeminacy syndrome in childhood. This has been considered evidence that the homosexuality comes from the twin himself. The possibility that the heterosexual twin was denying homosexuality has never been excluded. A pair of identical male twins discordant for homosexuality are reported. They showed significant differences in their penile volume responses to moving pictures of male and female nudes indicative of sexual orientations consistent with their statements. The homosexual twin showed the effeminacy syndrome. Aspects of the syndrome can be induced in mammals by altering their hormonal environment during some critical period in their intrauterine development. Discordance for homosexuality in identical twins could be due to one's being exposed to a different hormonal level during such a critical period.

  8. Non-random X chromosome inactivation in an affected twin in a monozygotic twin pair discordant for Wiedemann-Beckwith syndrome

    SciTech Connect

    Oestavik, R.E.; Eiklid, K.; Oerstavik, K.H.

    1995-03-27

    Wiedemann-Beckwith syndrome (WBS) is a syndrome including exomphalos, macroglossia, and generalized overgrowth. The locus has been assigned to 11p15, and genomic imprinting may play a part in the expression of one or more genes involved. Most cases are sporadic. An excess of female monozygotic twins discordant for WBS have been reported, and it has been proposed that this excess could be related to the process of X chromosome inactivation. We have therefore studied X chromosome inactivation in 13-year-old monozygotic twin girls who were discordant for WBS. In addition, both twins had Tourette syndrome. The twins were monochorionic and therefore the result of a late twinning process. This has also been the case in previously reported discordant twin pairs with information on placentation. X chromosome inactivation was determined in DNA from peripheral blood cells by PCR analysis at the androgen receptor locus. The affected twin had a completely skewed X inactivation, where the paternal allele was on the active X chromosome in all cells. The unaffected twin had a moderately skewed X inactivation in the same direction, whereas the mother had a random pattern. Further studies are necessary to establish a possible association between the expression of WBS and X chromosome inactivation. 18 refs., 2 figs., 1 tab.

  9. One CNV Discordance in NRXN1 Observed Upon Genome-wide Screening in 38 Pairs of Adult Healthy Monozygotic Twins.

    PubMed

    Magnusson, Patrik K E; Lee, Donghwan; Chen, Xu; Szatkiewicz, Jin; Pramana, Setia; Teo, Shumei; Sullivan, Patrick F; Feuk, Lars; Pawitan, Yudi

    2016-04-01

    Monozygotic (MZ) twins stem from the same single fertilized egg and therefore share all their inherited genetic variation. This is one of the unequivocal facts on which genetic epidemiology and twin studies are based. To what extent this also implies that MZ twins share genotypes in adult tissues is not precisely established, but a common pragmatic assumption is that MZ twins are 100% genetically identical also in adult tissues. During the past decade, this view has been challenged by several reports, with observations of differences in post-zygotic copy number variations (CNVs) between members of the same MZ pair. In this study, we performed a systematic search for differences of CNVs within 38 adult MZ pairs who had been misclassified as dizygotic (DZ) twins by questionnaire-based assessment. Initial scoring by PennCNV suggested a total of 967 CNV discordances. The within-pair correlation in number of CNVs detected was strongly dependent on confidence score filtering and reached a plateau of r = 0.8 when restricting to CNVs detected with confidence score larger than 50. The top-ranked discordances were subsequently selected for validation by quantitative polymerase chain reaction (qPCR), from which one single ~120kb deletion in NRXN1 on chromosome 2 (bp 51017111-51136802) was validated. Despite involving an exon, no sign of cognitive/mental consequences was apparent in the affected twin pair, potentially reflecting limited or lack of expression of the transcripts containing this exon in nerve/brain. PMID:26899349

  10. Alzheimer's disease in one monozygotic twin

    PubMed Central

    Hunter, Richard; Dayan, A. D.; Wilson, John

    1972-01-01

    A woman of 64 died after an illness lasting 15 years and characterized by a progressive amnesic syndrome followed by global dementia. The brain showed changes typical of Alzheimer's disease. Her monozygotic twin sister was clinically not affected and died two years later of carcinoma. This is the second report of monozygotic twin sisters apparently discordant for presenile dementia of Alzheimer type. PMID:5084139

  11. Increased Frequency of Micronuclei in Adults with a History of Childhood Sexual Abuse: A Discordant Monozygotic Twin Study

    PubMed Central

    York, Timothy P.; Brumelle, Jenni; Juusola, Jane; Kendler, Kenneth S.; Eaves, Lindon J.; Amstadter, Ananda B.; Aggen, Steven H.; Jones, Kimberly H.; Ferreira-Gonzalez, Andrea; Jackson-Cook, Colleen

    2013-01-01

    Background Childhood sexual abuse (CSA) is a traumatic life event associated with an increased lifetime risk for psychopathology/morbidity. The long-term biological consequences of CSA-elicited stress on chromosomal stability in adults are unknown. The primary aim of this study was to determine if the rate of acquired chromosomal changes, measured using the cytokinesis-block micronucleus assay on stimulated peripheral blood lymphocytes, differs in adult female monozygotic twins discordant for CSA. Methods Monozygotic twin pairs discordant for CSA were identified from a larger population-based sample of female adult twins for whom the experience of CSA was assessed by self-report (51 individuals including a reference sample). Micronuclei (MN) contain chromatin from structurally normal or abnormal chromosomes that are excluded from the daughter nuclei during cell division and serve as a biomarker to assess acquired chromosomal instability. Results Female twins exposed to CSA exhibited a 1.63-fold average increase in their frequency of MN compared to their nonexposed genetically identical cotwins (Paired t-test, t16 = 2.65, P = 0.017). No additional effects of familial factors were detected after controlling for the effect of CSA exposure. A significant interaction between CSA history and age was observed, suggesting that the biological effects of CSA on MN formation may be cumulative. Conclusions These data support a direct link between CSA exposure and MN formation measured in adults that is not attributable to genetic or environmental factors shared by siblings. Further research is warranted to understand the biological basis for the observed increase in acquired chromosomal findings in people exposed to CSA and to determine if acquired somatic chromosomal abnormalities/somatic clonal mosaicism might mediate the adult pathology associated with CSA. PMID:23383158

  12. Plasma proteomic profiles from disease-discordant monozygotic twins suggest that molecular pathways are shared in multiple systemic autoimmune diseases*

    PubMed Central

    2011-01-01

    Introduction Although systemic autoimmune diseases (SAID) share many clinical and laboratory features, whether they also share some common features of pathogenesis remains unclear. We assessed plasma proteomic profiles among different SAID for evidence of common molecular pathways that could provide insights into pathogenic mechanisms shared by these diseases. Methods Differential quantitative proteomic analyses (one-dimensional reverse-phase liquid chromatography-mass spectrometry) were performed to assess patterns of plasma protein expression. Monozygotic twins (four pairs discordant for systemic lupus erythematosus, four pairs discordant for juvenile idiopathic arthritis and two pairs discordant for juvenile dermatomyositis) were studied to minimize polymorphic gene effects. Comparisons were also made to 10 unrelated, matched controls. Results Multiple plasma proteins, including acute phase reactants, structural proteins, immune response proteins, coagulation and transcriptional factors, were differentially expressed similarly among the different SAID studied. Multivariate Random Forest modeling identified seven proteins whose combined altered expression levels effectively segregated affected vs. unaffected twins. Among these seven proteins, four were also identified in univariate analyses of proteomic data (syntaxin 17, α-glucosidase, paraoxonase 1, and the sixth component of complement). Molecular pathway modeling indicated that these factors may be integrated through interactions with a candidate plasma biomarker, PON1 and the pro-inflammatory cytokine IL-6. Conclusions Together, these data suggest that different SAID may share common alterations of plasma protein expression and molecular pathways. An understanding of the mechanisms leading to the altered plasma proteomes common among these SAID may provide useful insights into their pathogeneses. PMID:22044644

  13. Acquired obesity and poor physical fitness impair expression of genes of mitochondrial oxidative phosphorylation in monozygotic twins discordant for obesity.

    PubMed

    Mustelin, Linda; Pietiläinen, Kirsi H; Rissanen, Aila; Sovijärvi, Anssi R; Piirilä, Päivi; Naukkarinen, Jussi; Peltonen, Leena; Kaprio, Jaakko; Yki-Järvinen, Hannele

    2008-07-01

    Defects in expression of genes of oxidative phosphorylation in mitochondria have been suggested to be a key pathophysiological feature in familial insulin resistance. We examined whether such defects can arise from lifestyle-related factors alone. Fourteen obesity-discordant (BMI difference 5.2 +/- 1.8 kg/m(2)) and 10 concordant (1.0 +/- 0.7 kg/m(2)) monozygotic (MZ) twin pairs aged 24-27 yr were identified among 658 MZ pairs in the population-based FinnTwin16 study. Whole body insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp technique. Transcript profiles of mitochondrial genes were compared using microarray data of fat biopsies from discordant twins. Body composition of twins was determined using DEXA and maximal oxygen uptake (Vo(2max)) and working capacity (W(max)) using a bicycle ergometer exercise test with gas exchange analysis. The obese cotwins had lower insulin sensitivity than their nonobese counterparts (M value 6.1 +/- 2.0 vs. 9.2 +/- 3.2 mg x kg LBM(-1) x min(-1), P < 0.01). Transcript levels of genes involved in the oxidative phosphorylation pathway (GO:0006119) in adipose tissue were lower (P < 0.05) in the obese compared with the nonobese cotwins. The obese cotwins were also less fit, as measured by Vo(2max) (50.6 +/- 6.5 vs. 54.2 +/- 6.4 ml x kg LBM(-1) x min(-1), for obese vs. nonobese, P < 0.05), W(max) (3.9 +/- 0.5 vs. 4.4 +/- 0.7 W/kg LBM, P < 0.01) and also less active, by the Baecke leisure time physical activity index (2.8 +/- 0.5 vs. 3.3 +/- 0.6, P < 0.01). This implies that acquired poor physical fitness is associated with defective expression of the oxidative pathway components in adipose tissue mitochondria.

  14. Crossed cerebral lateralization for verbal and visuo-spatial function in a pair of handedness discordant monozygotic twins: MRI and fMRI brain imaging

    PubMed Central

    Lux, Silke; Keller, Simon; Mackay, Clare; Ebers, George; Marshall, John C; Cherkas, Lynne; Rezaie, Roozbeh; Roberts, Neil; Fink, Gereon R; Gurd, Jennifer M

    2008-01-01

    To examine the nature of hemispheric lateralization for neural processes underlying verbal fluency and visuo-spatial attention, we investigated a single pair of handedness discordant monozygotic (MzHd) twins. Imaging of the brain was undertaken using magnetic resonance imaging (MRI) and functional magnetic resonance imaging (fMRI) in combination with manual performance tasks. The twins were discordant for MRI anatomical asymmetries of the pars triangularis and planum temporale, whose asymmetry was consistent with verbal laterality on fMRI. Thus, the right-handed twin had left lateralized verbal with right lateralized visuo-spatial attention, while the left-handed twin had right lateralized verbal with left lateralized visuo-spatial activation; these data lend further support for to the conclusions of Sommer et al. PMID:18304205

  15. Acquired obesity and poor physical fitness impair expression of genes of mitochondrial oxidative phosphorylation in monozygotic twins discordant for obesity

    PubMed Central

    Mustelin, Linda; Pietiläinen, Kirsi H.; Rissanen, Aila; Sovijärvi, Anssi R.; Piirilä, Päivi; Naukkarinen, Jussi; Peltonen, Leena; Kaprio, Jaakko; Yki-Järvinen, Hannele

    2008-01-01

    Defects in expression of genes of oxidative phosphorylation in mitochondria have been suggested to be a key pathophysiological feature in familial insulin resistance. We examined whether such defects can arise from lifestyle-related factors alone. Fourteen obesity-discordant (BMI difference 5.2 ± 1.8 kg/m2) and 10 concordant (1.0 ± 0.7 kg/m2) monozygotic (MZ) twin pairs aged 24–27 yr were identified among 658 MZ pairs in the population-based FinnTwin16 study. Whole body insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp technique. Transcript profiles of mitochondrial genes were compared using microarray data of fat biopsies from discordant twins. Body composition of twins was determined using DEXA and maximal oxygen uptake (V̇o2max) and working capacity (Wmax) using a bicycle ergometer exercise test with gas exchange analysis. The obese cotwins had lower insulin sensitivity than their nonobese counterparts (M value 6.1 ± 2.0 vs. 9.2 ± 3.2 mg·kg LBM−1·min−1, P < 0.01). Transcript levels of genes involved in the oxidative phosphorylation pathway (GO:0006119) in adipose tissue were lower (P < 0.05) in the obese compared with the nonobese cotwins. The obese cotwins were also less fit, as measured by V̇o2max (50.6 ± 6.5 vs. 54.2 ± 6.4 ml·kg LBM−1·min−1, for obese vs. nonobese, P < 0.05), Wmax (3.9 ± 0.5 vs. 4.4 ± 0.7 W/kg LBM, P < 0.01) and also less active, by the Baecke leisure time physical activity index (2.8 ± 0.5 vs. 3.3 ± 0.6, P < 0.01). This implies that acquired poor physical fitness is associated with defective expression of the oxidative pathway components in adipose tissue mitochondria. PMID:18460597

  16. Modelling and rescuing neurodevelopmental defect of Down syndrome using induced pluripotent stem cells from monozygotic twins discordant for trisomy 21.

    PubMed

    Hibaoui, Youssef; Grad, Iwona; Letourneau, Audrey; Sailani, M Reza; Dahoun, Sophie; Santoni, Federico A; Gimelli, Stefania; Guipponi, Michel; Pelte, Marie Francoise; Béna, Frédérique; Antonarakis, Stylianos E; Feki, Anis

    2014-02-01

    Down syndrome (trisomy 21) is the most common viable chromosomal disorder with intellectual impairment and several other developmental abnormalities. Here, we report the generation and characterization of induced pluripotent stem cells (iPSCs) derived from monozygotic twins discordant for trisomy 21 in order to eliminate the effects of the variability of genomic background. The alterations observed by genetic analysis at the iPSC level and at first approximation in early development illustrate the developmental disease transcriptional signature of Down syndrome. Moreover, we observed an abnormal neural differentiation of Down syndrome iPSCs in vivo when formed teratoma in NOD-SCID mice, and in vitro when differentiated into neuroprogenitors and neurons. These defects were associated with changes in the architecture and density of neurons, astroglial and oligodendroglial cells together with misexpression of genes involved in neurogenesis, lineage specification and differentiation. Furthermore, we provide novel evidence that dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A) on chromosome 21 likely contributes to these defects. Importantly, we found that targeting DYRK1A pharmacologically or by shRNA results in a considerable correction of these defects. PMID:24375627

  17. Modelling and rescuing neurodevelopmental defect of Down syndrome using induced pluripotent stem cells from monozygotic twins discordant for trisomy 21

    PubMed Central

    Hibaoui, Youssef; Grad, Iwona; Letourneau, Audrey; Sailani, M Reza; Dahoun, Sophie; Santoni, Federico A; Gimelli, Stefania; Guipponi, Michel; Pelte, Marie Françoise; Béna, Frédérique; Antonarakis, Stylianos E; Feki, Anis

    2014-01-01

    Down syndrome (trisomy 21) is the most common viable chromosomal disorder with intellectual impairment and several other developmental abnormalities. Here, we report the generation and characterization of induced pluripotent stem cells (iPSCs) derived from monozygotic twins discordant for trisomy 21 in order to eliminate the effects of the variability of genomic background. The alterations observed by genetic analysis at the iPSC level and at first approximation in early development illustrate the developmental disease transcriptional signature of Down syndrome. Moreover, we observed an abnormal neural differentiation of Down syndrome iPSCs in vivo when formed teratoma in NOD-SCID mice, and in vitro when differentiated into neuroprogenitors and neurons. These defects were associated with changes in the architecture and density of neurons, astroglial and oligodendroglial cells together with misexpression of genes involved in neurogenesis, lineage specification and differentiation. Furthermore, we provide novel evidence that dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A ( DYRK1A) on chromosome 21 likely contributes to these defects. Importantly, we found that targeting DYRK1A pharmacologically or by shRNA results in a considerable correction of these defects. PMID:24375627

  18. The occurrence of gonadal dysgenesis in association with monozygotic twinning.

    PubMed Central

    Karp, L; Bryant, J I; Tagatz, G; Giblett, E; Fialkow, P J

    1975-01-01

    A case is presented of a monozygotic twin pair, discordant for phenotypic sex, in which the female member showed gonadal dysgenesis and chromosomal mosaicism. Review of the pertinent literature reveals that in monozygotic twin pairs, phenotypic and karyotypic concordance is the usual occurrence for Down's and Klinefelter's syndromes, whereas discordance often accompanies gonadal dysgenesis. Mosaicism is a frequent concomitant of gonadal dysgenesis in monozygotic twins. Our case strengthens the probability of a real association between mosaicism and monozygotic twinning in gonadal dysgenesis. Images PMID:1121022

  19. A Novel Model of Schizophrenia Age-of-Onset Data Challenges the Conventional Interpretations of the Discordance in Monozygote Twin Studies.

    PubMed

    Kramer, Ivan; Hong, L Elliot

    2013-01-01

    The relative importance of genetics and the environment in causing schizophrenia is still being debated. Although the high proportion of monozygote cotwins of schizophrenia patients who are discordant suggests that there may be a significant environmental contribution to the development of schizophrenia, this discordance is predicted by an accumulative multimutation model of schizophrenia onset constructed here implying a genetic origin of schizophrenia. In this model, schizophrenics are viewed as having been born with the genetic susceptibility to develop schizophrenia. As susceptible gene carriers age, they randomly accumulate the necessary mutations to cause schizophrenia, the last needed mutation coinciding with disease onset. The mutation model predicts that the concordance rate in monozygote twin studies will monotonically increase with age, theoretically approaching 100% given sufficient longevity. In dizygote cotwins of schizophrenia patients, the model predicts that at least 71% of cotwins are incapable of developing schizophrenia even though every cotwin and their schizophrenic twin shared a similar early environment. The multimutation model is shown to fit all of the monozygote and dizygote concordance rate data of the principle classical twin studies completed before 1970 considered in this paper. Thus, the genetic hypothesis of schizophrenia can be tested by bringing these studies up to date.

  20. Genome-Wide Analysis of DNA Methylation, Copy Number Variation, and Gene Expression in Monozygotic Twins Discordant for Primary Biliary Cirrhosis

    PubMed Central

    Selmi, Carlo; Cavaciocchi, Francesca; Lleo, Ana; Cheroni, Cristina; De Francesco, Raffaele; Lombardi, Simone A.; De Santis, Maria; Meda, Francesca; Raimondo, Maria Gabriella; Crotti, Chiara; Folci, Marco; Zammataro, Luca; Mayo, Marlyn J.; Bach, Nancy; Shimoda, Shinji; Gordon, Stuart C.; Miozzo, Monica; Invernizzi, Pietro; Podda, Mauro; Scavelli, Rossana; Martin, Michelle R.; Seldin, Michael F.; LaSalle, Janine M.; Gershwin, M. Eric

    2014-01-01

    Primary biliary cirrhosis (PBC) is an uncommon autoimmune disease with a homogeneous clinical phenotype that reflects incomplete disease concordance in monozygotic (MZ) twins. We have taken advantage of a unique collection consisting of genomic DNA and mRNA from peripheral blood cells of female MZ twins (n = 3 sets) and sisters of similar age (n = 8 pairs) discordant for disease. We performed a genome-wide study to investigate differences in (i) DNA methylation (using a custom tiled four-plex array containing tiled 50-mers 19,084 randomly chosen methylation sites), (ii) copy number variation (CNV) (with a chip including markers derived from the 1000 Genomes Project, all three HapMap phases, and recently published studies), and/or (iii) gene expression (by whole-genome expression arrays). Based on the results obtained from these three approaches we utilized quantitative PCR to compare the expression of candidate genes. Importantly, our data support consistent differences in discordant twins and siblings for the (i) methylation profiles of 60 gene regions, (ii) CNV of 10 genes, and (iii) the expression of 2 interferon-dependent genes. Quantitative PCR analysis showed that 17 of these genes are differentially expressed in discordant sibling pairs. In conclusion, we report that MZ twins and sisters discordant for PBC manifest particular epigenetic differences and highlight the value of the epigenetic study of twins. PMID:24734033

  1. Increased serotonin transporter gene (SERT) DNA methylation is associated with bullying victimization and blunted cortisol response to stress in childhood: a longitudinal study of discordant monozygotic twins

    PubMed Central

    Ouellet-Morin, I.; Wong, C. C. Y.; Danese, A.; Pariante, C. M.; Papadopoulos, A. S.; Mill, J.; Arseneault, L.

    2014-01-01

    Background Childhood adverse experiences are known to induce persistent changes in the hypothalamic–pituitary–adrenal (HPA) axis reactivity to stress. However, the mechanisms by which these experiences shape the neuroendocrine response to stress remain unclear. Method We tested whether bullying victimization influenced serotonin transporter gene (SERT) DNA methylation using a discordant monozygotic (MZ) twin design. A subsample of 28 MZ twin pairs discordant for bullying victimization, with data on cortisol and DNA methylation, were identified in the Environmental Risk (E-Risk) Longitudinal Twin Study, a nationally representative 1994–1995 cohort of families with twins. Results Bullied twins had higher SERT DNA methylation at the age of 10 years compared with their non-bullied MZ co-twins. This group difference cannot be attributed to the children’s genetic makeup or their shared familial environments because of the study design. Bullied twins also showed increasing methylation levels between the age of 5 years, prior to bullying victimization, and the age of 10 years whereas no such increase was detected in non-bullied twins across time. Moreover, children with higher SERT methylation levels had blunted cortisol responses to stress. Conclusions Our study extends findings drawn from animal models, supports the hypothesis that early-life stress modifies DNA methylation at a specific cytosine–phosphate–guanine (CpG) site in the SERT promoter and HPA functioning and suggests that these two systems may be functionally associated. PMID:23217646

  2. Uneven X inactivation in a female monozygotic twin pair with Fabry disease and discordant expression of a novel mutation in the alpha-galactosidase A gene.

    PubMed Central

    Redonnet-Vernhet, I; Ploos van Amstel, J K; Jansen, R P; Wevers, R A; Salvayre, R; Levade, T

    1996-01-01

    We describe two female monozygotic (MZ) twins heterozygous for Fabry disease, an X linked disorder resulting from the deficient activity of alpha-galactosidase A. While one of the twins was clinically affected, the other was asymptomatic. Enzymatic assay of alpha-galactosidase in blood leucocytes, skin fibroblasts, Epstein-Barr virus transformed lymphoid cell lines, and hair follicles of the twins and their parents confirmed the heterozygous status of the twins and indicated that Fabry disease had occurred as a result of a de novo mutation. The son of the unaffected twin sister was shown to be hemizygous. Molecular analysis of the alpha-galactosidase A gene permitted the identification of an as yet undescribed point mutation at position 10182 of exon 5 which causes an Asp to Asn substitution at codon 231. Single strand conformation polymorphism (SSCP) analysis again showed the heterozygous status of the twins and a normal pattern in their parents. The basis for the discordant expression of this d novo mutation in the twins was investigated by studying their X inactivation status. Analysis of the inactive X specific methylation at the androgen receptor gene showed unbalanced inactivation in the twins' fibroblasts and in opposite directions. While the maternally derived X chromosome was preferentially active in the asymptomatic twin, the paternal X chromosome was active in the other, affected twin and was found in her hemizygotic nephew. These data suggest that the paternal X chromosome carries the de novo alpha-galactosidase A mutation and that uneven X inactivation is the underlying mechanism for disease expression in this novel female MZ twin pair. This is the first documented case of female twins discordant for Fabry disease. Images PMID:8863162

  3. Somatic Mutations Are Not Observed by Exome Sequencing of Lymphocyte DNA from Monozygotic Twins Discordant for Congenital Hypothyroidism due to Thyroid Dysgenesis

    PubMed Central

    Magne, Fabien; Serpa, Roman; Van Vliet, Guy; Samuels, Mark E.; Deladoëy, Johnny

    2016-01-01

    Background/Aims Congenital primary hypothyroidism (CH) is a rare pediatric disorder estimated to occur in about 1: 2,500 live births. Approximately half of these cases entail ectopic thyroid tissue, which is believed to result from a migration defect during embryogenesis. Approximately 3% of CH cases are explained by mutation(s) in known genes, most of which are transcription factors implicated in the embryology of the thyroid gland. Surprisingly, monozygotic (MZ) twins are usually discordant for CH due to thyroid dysgenesis, suggesting that most cases are not caused by transmitted genetic variation. One possible explanation is somatic mutation in genes involved in thyroid migration occurring after zygotic twinning. Such mutations should be observed only in the affected twin. Methods To test the hypothesis of somatic mutation, we performed whole exome sequencing of DNA from three pairs of MZ twins discordant for CH with ectopic glands. Results We found no somatic mutations exclusive to any of the three affected twins or in any of the unaffected twins. Conclusion Either somatic mutations are not significant for the etiology of CH or else such mutations lie outside regions of the genome accessible by exome sequencing technology. PMID:25277881

  4. Discordant sex in one of three monozygotic triplets.

    PubMed Central

    Dallapiccola, B; Stomeo, C; Ferranti, G; Di Lecce, A; Purpura, M

    1985-01-01

    A case is reported of monozygotic triplets, discordant for phenotypic sex, in which the female presented at birth with the features of Turner's syndrome. Chromosomal analyses showed homogeneous 46,XY karyotypes in the lymphocytes of the three sibs, while a 45,X non-mosaic chromosome constitution was detected in skin fibroblasts of the female triplet. It is suggested that mitotic non-disjunction or anaphase lag occurring early during embryonic development accounted for the occurrence of monosomy X in one cell line of the affected triplet. Previous observations of monozygotic twin pairs discordant for chromosome constitutions are reviewed. Images PMID:3856681

  5. X-CHROMOSOME INACTIVATION PATTERNS IN MONOZYGOTIC TWINS AND SIB PAIRS DISCORDANT FOR NON-SYNDROMIC CLEFT LIP AND/OR PALATE

    PubMed Central

    Kimani, Jane W.; Shi, Min; Daack-Hirsch, Sandra; Christensen, Kaare; Moretti-Ferreira, Danilo; Marazita, Mary L.; Field, Leigh L.; Canady, John W.; Murray, Jeffrey C.

    2009-01-01

    Background Orofacial clefts are common birth defects with a complex etiology. While underlying mechanisms are still largely unknown, altered gender ratios for clefting phenotypes, evidence for linkage to the X chromosome and the occurrence of several X-linked clefting syndromes suggest that skewed X chromosome inactivation (XCI) may contribute to the etiology of orofacial clefting. We tested this hypothesis in a sample set of female monozygotic (MZ) twins and sister pairs discordant for clefting. Methods We determined XCI in peripheral blood lymphocyte DNA using a methylation based androgen receptor gene assay. We measured skewing of XCI as the deviation in XCI pattern from a 50:50 ratio and used a paired t-test to compare the degree of skewing in cases and their unaffected sisters. Results Our analysis revealed no significant difference in the degree of skewing between twin pairs (P=0.3). However, significant differences were observed in the sister pairs (P=0.02), with the cleft lip with cleft palate (CL+P) group showing the most significant result (P=0.01). Results from the cleft lip only (P=0.79) and cleft palate only (P=0.75) groups were not significant. Conclusions We did not find evidence for involvement of skewed XCI in the discordance for clefting in our sample of female MZ twins. However, results from the paired sister study suggest that skewed XCI may be important in orofacial clefting, particularly CL+P. PMID:18000982

  6. (Epi)genomics and neurodevelopment in schizophrenia: monozygotic twins discordant for schizophrenia augment the search for disease-related (epi)genomic alterations.

    PubMed

    Singh, Shiva M; O'Reilly, Richard

    2009-01-01

    Unlike stunning breakthroughs in the identification of genes for Mendelian disorders during the last three decades, gene identification in most complex disorders has been full of twists and turns and little progress. Doing more of the same will not guarantee success. The lessons learned argue for a need to reconsider genetic models that are appropriate for the disorder in question along with an interdisciplinary, systematic approach using genomic methods that have now become possible. We will use schizophrenia as an example to review the genetic progress to date that has been disappointing. We will argue that the causation of this complex disease may involve heterogeneous genomic changes of major effect. We will provide three approaches, retroviral transpositions, methylation, and copy number variations, to test this hypothesis. We will present arguments to suggest that such experiments will be most effective if undertaken on monozygotic twins. It will include our experience with associated experiments on the monozygotic twins discordant for schizophrenia. The results support that (epi)genomic changes of major effect, rather than accumulation of mutations of small effect, underlie the causation of this complex disease. More important, this experimental strategy will be an effective strategy for studies on other complex (behavioural) disorders as well.

  7. Birthweight-discordance and differences in early parenting relate to monozygotic twin differences in behaviour problems and academic achievement at age 7.

    PubMed

    Asbury, Kathryn; Dunn, Judith F; Plomin, Robert

    2006-03-01

    This longitudinal monozygotic (MZ) twin differences study explored associations between birthweight and early family environment and teacher-rated behaviour problems and academic achievement at age 7. MZ differences in anxiety, hyperactivity, conduct problems, peer problems and academic achievement correlated significantly with MZ differences in birthweight and early family environment, showing effect sizes of up to 2%. As predicted by earlier research, associations increased at the extremes of discordance, even in a longitudinal, cross-rater design, with effect sizes reaching as high as 12%. As with previous research some of these non-shared environmental (NSE) relationships appeared to operate partly as a function of SES, family chaos and maternal depression. Higher-risk families generally showed stronger negative associations.

  8. Volume of cerebellar vermis in monozygotic twins discordant for combat exposure: Lack of relationship to post-traumatic stress disorder

    PubMed Central

    Levitt, James J.; Chen, Q. Cece; May, Flavia S.; Gilbertson, Mark W.; Shenton, Martha E.; Pitman, Roger K.

    2009-01-01

    Several functional neuroimaging studies have implicated the cerebellar vermis in post-traumatic stress disorder (PTSD), but there have been no structural neuroimaging studies of this brain structure in PTSD. We utilized magnetic resonance imaging (MRI) with manual tracing to quantify the volumes of three divisions of the mid-sagittal vermis, and their total, within an identical, cotwin control design that employed Vietnam veterans discordant for combat exposure in Vietnam. Each structure’s volume was significantly correlated between twins, indicating a partial familial determination: for anterior superior vermis, r=0.73; for posterior superior vermis, r=0.47; for inferior posterior vermis, r=0.51; and for total vermis, r=0.57. There were no significant differences between the PTSD and non-PTSD veterans for any vermis volume, and no significant main effects or interactions when their non-combat-exposed co-twins were added to the analyses. Thus, the results do not support the structural abnormality of cerebellar vermis in combat-related PTSD. PMID:17097862

  9. Effects of type II collagen epitope carbamylation and citrullination in human leucocyte antigen (HLA)-DR4(+) monozygotic twins discordant for rheumatoid arthritis.

    PubMed

    De Santis, M; Ceribelli, A; Cavaciocchi, F; Generali, E; Massarotti, M; Isailovic, N; Crotti, C; Scherer, H U; Montecucco, C; Selmi, C

    2016-09-01

    The aim of this study is to investigate the effect of the native, citrullinated or carbamylated type II human collagen T cell- and B cell-epitopes on the adaptive immune response in rheumatoid arthritis (RA). Peripheral blood T and B cells obtained from a human leucocyte D4-related (antigen DR4(-) HLA-DR4)(+) woman with early RA, her healthy monozygotic twin and an unrelated HLA-DR3(+) woman with early RA were analysed for activation (CD154/CD69), apoptosis (annexin/7-aminoactinomycin), cytokine production [interferon (IFN)γ/interleukin (IL)-17/IL-4/IL-10/IL-6] and functional phenotype (CD45Ra/CCR7) after stimulation with the collagen native T cell epitope (T261-273), the K264 carbamylated T cell epitope (carT261-273), the native B cell epitope (B359-369) or the R360 citrullinated B cell epitope (citB359-369), and the combinations of these. The T cell memory compartment was activated by T cell epitopes in both discordant DR4(+) twins, but not in the DR3(+) RA. The collagen-specific activation of CD4(+) T cells was induced with both the native and carbamylated T cell epitopes only in the RA twin. Both T cell epitopes also induced IL-17 production in the RA twin, but a greater IL-4 and IL-10 response in the healthy twin. The citrullinated B cell epitope, particularly when combined with the carbamylated T cell epitope, induced B cell activation and an increased IL-6/IL-10 ratio in the RA twin compared to a greater IL-10 production in the healthy twin. Our data suggest that circulating collagen-specific T and B cells are found in HLA-DR4(+) subjects, but only RA activated cells express co-stimulatory molecules and produce proinflammatory cytokines. Carbamylation and citrullination further modulate the activation and cytokine polarization of T and B cells. PMID:27314557

  10. Amino Acid Intakes Are Associated With Bone Mineral Density and Prevalence of Low Bone Mass in Women: Evidence From Discordant Monozygotic Twins.

    PubMed

    Jennings, Amy; MacGregor, Alexander; Spector, Tim; Cassidy, Aedín

    2016-02-01

    Although a higher protein intake, particularly from vegetable sources, has been shown to be associated with higher bone mineral density (BMD) the relative impact of specific amino acids on BMD and risk of osteoporosis remains to be determined. Mechanistic research suggests that a number of specific amino acids, including five nonessential amino acids--alanine, arginine, glutamic acid, glycine, and proline--may play a role in bone health, principally through improved production of insulin and insulin-like growth factor 1 and the synthesis of collagen and muscle protein. However to date, no previous studies have examined the associations between habitual intake of amino acids and direct measures of BMD and prevalence of osteoporosis or osteopenia, and no studies have examined this relationship in discordant identical twin-pairs. In these analyses of female monozygotic twin-pairs discordant for amino acid intake (n = 135), twins with higher intakes of alanine and glycine had significantly higher BMD at the spine than their co-twins with within-pair differences in spine-BMD of 0.012 g/cm(2) (SE 0.01; p = 0.039) and 0.014 g/cm(2) (SE 0.01; p = 0.026), respectively. Furthermore, in cross-sectional multivariable analyses of 3160 females aged 18 to 79 years, a higher intake of total protein was significantly associated with higher DXA-measured BMD at the spine (quartile Q4 to quartile Q1: 0.017 g/cm(2), SE 0.01, p = 0.035) and forearm (Q4 to Q1: 0.010 g/cm(2), SE 0.003, p = 0.002). Intake of six amino acids (alanine, arginine, glutamic acid, leucine, lysine, and proline) were associated with higher BMD at the spine and forearm with the strongest association observed for leucine (Q4 to Q1: 0.024 g/cm(2), SE 0.01, p = 0.007). When intakes were stratified by protein source, vegetable or animal, prevalence of osteoporosis or osteopenia was 13% to 19% lower comparing extreme quartiles of vegetable intake for five amino acids (not glutamic acid or proline). These data provide

  11. Biliary lipid composition in monozygotic and dizygotic pairs of twins.

    PubMed Central

    Antero Kesäniemi, Y; Koskenvuo, M; Vuoristo, M; Miettinen, T A

    1989-01-01

    The relative contribution of genetic factors to biliary and serum lipid composition was studied in 17 monozygotic and 18 dizygotic middle aged male pairs of twins. Cholesterol precursors, squalene and Methylated sterols which reflect the activity of cholesterol synthesis were also measured. Pairwise intraclass correlations were determined for monozygotic and dizygotic twin pairs and heritability estimates were calculated. Molar % of biliary cholesterol and percentage distribution of biliary cholic acid and particularly deoxycholic acid showed significant pairwise correlations within the monozygotic but not the dizygotic pairs. Similar correlations were found for total biliary methylsterols and of the methylsterol subfractions for the two methostenols but not for squalene, lanosterol and dimethylsterols. In serum, the precursor sterols, but not squalene, showed even higher pairwise correlations in the monozygotic twins than the corresponding precursors in bile. Molar per cent of bile acids and phospholipids and cholesterol saturation index were not correlated significantly in either twin pairs, but the pairwise correlations tended to be higher in the monozygotic than in the dizygotic pairs. Gall stones were found in seven monozygotic and three dizygotic subjects. Two monozygotic twin pairs were concordant for gall stones; all the dizygotic pairs were discordant. Overall, these data suggest that molar percentage of biliary cholesterol, bile acid composition, cholesterol synthesis, bile cholesterol saturation, and gall stone formation may be under a significant genetic control. PMID:2612989

  12. Birthweight-Discordance and Differences in Early Parenting Relate to Monozygotic Twin Differences in Behaviour Problems and Academic Achievement at Age 7

    ERIC Educational Resources Information Center

    Asbury, Kathryn; Dunn, Judith F.; Plomin, Robert

    2006-01-01

    This longitudinal monozygotic (MZ) twin differences study explored associations between birthweight and early family environment and teacher-rated behaviour problems and academic achievement at age 7. MZ differences in anxiety, hyperactivity, conduct problems, peer problems and academic achievement correlated significantly with MZ differences in…

  13. Culture systems: embryo culture and monozygotic twinning.

    PubMed

    Sparks, Amy E

    2012-01-01

    The incidence of monozygotic twinning in pregnancies achieved with assisted reproductive technologies (ART) is significantly higher than spontaneously conceived pregnancies. The factors associated with ART that predispose the embryos to splitting are not well-characterized. Assisted hatching and extended embryo culture are two ART laboratory methods that have been risk factors for monozygotic twinning. The methods and strategies that may be employed to avoid monozygotic twinning are discussed in this chapter.

  14. Monozygotic twins: genes are not the destiny?

    PubMed

    Chatterjee, Aniruddha; Morison, Ian M

    2011-01-01

    Monozygotic twins are considered to be genetically identical, yet can show high discordance in their phenotypes and disease susceptibility. Several studies have emphasized the influence of external factors and the role of epigenetic polymorphism in conferring this variability. However, some recent high-resolution studies on DNA methylation show contradicting evidence, which poses questions on the extent of epigenetic variability between twins. The advent of next-generation sequencing technologies now allow us to interrogate multiple epigenomes on a massive scale and understand the role of epigenetic modification, especially DNA methylation, in regulating complex traits. This article briefly discusses the recent key findings, unsolved questions in the area, and speculates on the future directions in the field. PMID:22355239

  15. Epigenetic discordance at imprinting control regions in twins.

    PubMed

    Ollikainen, Miina; Craig, Jeffrey M

    2011-06-01

    Imprinting control regions are differentially methylated in a parent-of-origin-dependent manner and this methylation state is inherited through the germline. These regions control parent-specific monoallelic expression of their target genes. Genetically identical organisms show considerable variation in their epigenomes owing to environmental and stochastic influences creating fluctuations in phenotype. Monozygotic twin pairs discordant for imprinting disorders due to epigenetic changes at imprinting control regions are an example of phenotypic variation caused by extreme variations of the epigenome. Here, we discuss the within-pair epigenetic discordance at imprinted loci, both in phenotypically concordant and discordant monozygotic twin pairs. PMID:22122339

  16. Childhood infections and adult height in monozygotic twin pairs.

    PubMed

    Hwang, Amie E; Mack, Thomas M; Hamilton, Ann S; Gauderman, W James; Bernstein, Leslie; Cockburn, Myles G; Zadnick, John; Rand, Kristin A; Hopper, John L; Cozen, Wendy

    2013-08-15

    Adult height is determined by genetics and childhood nutrition, but childhood infections may also play a role. Monozygotic twins are genetically matched and offer an advantage when identifying environmental determinants. In 2005-2007, we examined the association of childhood infections with adult height in 140 height-discordant monozygotic twin pairs from the California Twin Program. To obtain information on childhood infections and growth, we interviewed the mothers of monozygotic twins who differed in self-reported adult height by at least 1-inch (2.5 cm). Within-pair differences in the relative frequency of childhood infections were highly correlated, especially within age groups. A conditional logistic regression analysis demonstrated that more reported episodes of febrile illness occurred in the twin with shorter stature (odds ratio = 2.00, 95% confidence interval: 1.18, 3.40). The association was strongest for differences in the relative frequency of infection during the toddler years (ages 1-5: odds ratio = 3.34, 95% confidence interval: 1.47, 7.59) and was similar when restricted to twin pairs of equal birth length. The association was not explained by differential nutritional status. Measures of childhood infection were associated with height difference in monozygotic twin pairs, independent of genome, birth length, and available measures of diet. PMID:23585330

  17. Serum microRNAs explain discordance of non-alcoholic fatty liver disease in monozygotic and dizygotic twins: a prospective study

    PubMed Central

    Zarrinpar, Amir; Gupta, Shakti; Maurya, Mano R; Subramaniam, Shankar; Loomba, Rohit

    2016-01-01

    Objective In the setting where two individuals are genetically similar, epigenetic mechanisms could account for discordance in the presence or absence of nonalcoholic fatty liver disease (NAFLD). This study investigated if serum microRNAs (miRs) could explain discordance in NAFLD. Design This is a cross-sectional analysis of a prospective cohort study of 40 (n=80) twin-pairs residing in Southern California. All participants underwent a standardised research visit, liver MRI using proton-density fat fraction to quantify fat content and miR profiling of their serum. Results Among the 40 twin-pairs, there were 6 concordant for NAFLD, 28 were concordant for non-NAFLD and 6 were discordant for NAFLD. The prevalence of NAFLD was 22.5% (18/80). Within the six discordant twins, a panel of 10 miRs differentiated the twin with NAFLD from the one without. Two of these miRs, miR-331-3p and miR-30c, were also among the 21 miRs that were different between NAFLD and non-NAFLD groups (for miR-331-3p: 7.644±0.091 vs 8.057 ±0.071, respectively, p=0.004; for miR-30c: 10.013 ±0.126 vs 10.418±0.086, respectively, p=0.008). Both miRs were highly heritable (35.9% and 10.7%, respectively) and highly correlated with each other (R=0.90, p=2.2×10−16) suggesting involvement in a common mechanistic pathway. An interactome analysis of these two miRs showed seven common target genes. Conclusions Using a novel human twin-study design, we demonstrate that discordancy in liver fat content between the twins can be explained by miRs, and that they are heritable. PMID:26002934

  18. Motor Disorder and Anxious and Depressive Symptomatology: A Monozygotic Co-Twin Control Approach

    ERIC Educational Resources Information Center

    Pearsall-Jones, Jillian G.; Piek, Jan P.; Rigoli, Daniela; Martin, Neilson C.; Levy, Florence

    2011-01-01

    The aim of this study was to investigate the relationship between poor motor ability and anxious and depressive symptomatology in child and adolescent monozygotic twins. The co-twin control design was used to explore these mental health issues in MZ twins concordant and discordant for a motor disorder, and controls. This methodology offers the…

  19. Discordance of Prenatal and Neonatal Brain Development in Twins

    PubMed Central

    Mukherjee, Niyati; Kang, Chaeryon; Wolfe, Honor M.; Hertzberg, Barbara S.; Smith, J. Keith; Lin, Weili; Gerig, Guido; Hamer, Robert M.; Gilmore, John H.

    2009-01-01

    Background Discordance of birth weight has been observed in twin pairs, though little is known about prenatal and early neonatal discordance of head and brain size, and the role that zygosity and chorionicity play in discordances of early brain development in twins. Aims To compare prenatal and neonatal discordances of head size in monozygotic –monochorionic (MZ-MC), monozygotic-dichorionic (MZ-DC), and same-sex dizygotic-dichorionic twin pairs (DZ). Study Design Subjects prospectively had ultrasounds at 22 and 32 weeks gestational age, and magnetic resonance imaging (MRI) of the brain MRI after birth. Subjects 88 twin pairs recruited from two university hospital prenatal diagnostic clinics; 22 MZ-MC, 17 MZ-DC, and 49 same sex DZ pairs. Outcome measures Discordance of head circumference (HC) and weight at 22 weeks, 32 weeks and birth, as well as intracranial volume (ICV) on neonatal MRI. Results There were no group differences in discordance of head circumference and weight on the 22 or 32 week ultrasounds, or at birth. MZ-MC twins tended to have numerically greater discordances of HC and weight. There was a significant group difference in ICV on neonatal MRI (ANOVA, p = 0.0143), with DZ twins having significantly greater discordance than MZ-MC (p = 0.028) or MZ-DC (p = 0.0131) twins. Conclusions This study indicates that zygosity and chorionicity do not contribute to significant discordances of head size in late prenatal development. DZ twins do have significantly greater discordances of ICV on neonatal MRI, suggesting a relatively greater genetic influence on brain growth in the first weeks after birth. PMID:18804925

  20. Monozygotic twins discordant for recessive dystrophic epidermolysis bullosa phenotype highlight the role of TGF-β signalling in modifying disease severity.

    PubMed

    Odorisio, Teresa; Di Salvio, Michela; Orecchia, Angela; Di Zenzo, Giovanni; Piccinni, Eugenia; Cianfarani, Francesca; Travaglione, Antonella; Uva, Paolo; Bellei, Barbara; Conti, Andrea; Zambruno, Giovanna; Castiglia, Daniele

    2014-08-01

    Recessive dystrophic epidermolysis bullosa (RDEB) is a genodermatosis characterized by fragile skin forming blisters that heal invariably with scars. It is due to mutations in the COL7A1 gene encoding type VII collagen, the major component of anchoring fibrils connecting the cutaneous basement membrane to the dermis. Identical COL7A1 mutations often result in inter- and intra-familial disease variability, suggesting that additional modifiers contribute to RDEB course. Here, we studied a monozygotic twin pair with RDEB presenting markedly different phenotypic manifestations, while expressing similar amounts of collagen VII. Genome-wide expression analysis in twins' fibroblasts showed differential expression of genes associated with TGF-β pathway inhibition. In particular, decorin, a skin matrix component with anti-fibrotic properties, was found to be more expressed in the less affected twin. Accordingly, fibroblasts from the more affected sibling manifested a profibrotic and contractile phenotype characterized by enhanced α-smooth muscle actin and plasminogen activator inhibitor 1 expression, collagen I release and collagen lattice contraction. These cells also produced increased amounts of proinflammatory cytokines interleukin 6 and monocyte chemoattractant protein-1. Both TGF-β canonical (Smads) and non-canonical (MAPKs) pathways were basally more activated in the fibroblasts of the more affected twin. The profibrotic behaviour of these fibroblasts was suppressed by decorin delivery to cells. Our data show that the amount of type VII collagen is not the only determinant of RDEB clinical severity, and indicate an involvement of TGF-β pathways in modulating disease variability. Moreover, our findings identify decorin as a possible anti-fibrotic/inflammatory agent for RDEB therapeutic intervention. PMID:24599399

  1. Monozygotic Twins with Asperger Syndrome: Differences in Behaviour Reflect Variations in Brain Structure and Function

    ERIC Educational Resources Information Center

    Belmonte, Matthew K.; Carper, Ruth A.

    2006-01-01

    A pair of monozygotic twins discordant for symptoms of Asperger syndrome was evaluated at the age of 13.45 years using psychometric, morphometric, behavioural, and functional imaging methods. The lower-functioning twin had a smaller brain overall, a smaller right cerebellum, and a disproportionately large left frontal lobe, and manifested almost…

  2. X-chromosome inactivation is mostly random in placental tissues of female monozygotic twins and triplets

    SciTech Connect

    Bamforth, F.; Machin, G.; Innes, M.

    1996-01-22

    Patterns of X-chromosome inactivation in chorion, amnion, and cord from 79 pairs of twins were examined. Seven sets of triplets were included in the analysis, both as twin pairs and triplets. Twins were stratified as dizygotic (DZ), monozygotic (MZ), monochorionic, and dichorionic and were selected for birth weight discordance, discordance for congenital anomalies, twin-twin transfusion syndrome, and various patterns of vascular anastomosis. X-inactivation was predominantly symmetric. Chorion was the most likely tissue to show asymmetric X-inactivation and was found most frequently in MZ dichorionic twins. There was no correlation of X-inactivation pattern with the selected clinical criteria. This study does not confirm that asymmetric X-inactivation in embryonic tissues is a common phenomenon in female twins, including monozygotic twins. 27 refs., 2 figs., 9 tabs.

  3. Monoamniotic monochorionic twins discordant for noncompaction cardiomyopathy.

    PubMed

    Ng, Dianna; Bouhlal, Yosr; Ursell, Philip C; Shieh, Joseph T C

    2013-06-01

    Occasionally "identical twins" are phenotypically different, raising the question of zygosity and the issue of genetic versus environmental influences during development. We recently noted monochorionic-monoamniotic twins, one of which had an isolated cardiac abnormality, noncompaction cardiomyopathy, a condition characterized by cardiac ventricular hypertrabeculation. We examined the prenatal course and subsequent pathologic correlation since ventricular morphogenesis may depend on early muscular contraction and blood flow. The monochorionic-monoamniotic female twin pair was initially identified since one fetus presented with increased nuchal translucency. Complete heart block was later identified in the fetus with nuchal translucency who did not survive after delivery. In contrast, the unaffected twin had normal cardiac studies both prenatally and postnatally. Pathologic analysis of the affected twin demonstrated noncompaction of the left ventricle with dysplasia of the aortic and pulmonary valves. Dissection of the cardiac conduction system disclosed atrioventricular bundle fibrosis. Maternal lupus studies, amniocentesis with karyotype, and studies for 22q11.2 were normal. To test for zygosity, we performed multiple STR marker analysis and found that all markers were shared even using nonblood tissues from the affected twin. These studies demonstrate that monozygotic twins that are monochorionic monoamniotic can be discordant for cardiac noncompaction. The results suggest further investigation into the potential roles of pathologic fibrosis, contractility, and blood flow in cardiac ventricle development. PMID:23636980

  4. Evolutionary trajectories of hyperdiploid ALL in monozygotic twins.

    PubMed

    Bateman, C M; Alpar, D; Ford, A M; Colman, S M; Wren, D; Morgan, M; Kearney, L; Greaves, M

    2015-01-01

    Identical twins have provided unique insights on timing or sequence of genetic events in acute lymphoblastic leukaemia (ALL). To date, this has mainly focused on ALL with MLL or ETV6-RUNX1 fusions, with hyperdiploid ALL remaining less well characterised. We examined three pairs of monozygotic twins, two concordant and one discordant for hyperdiploid ALL, for single-nucleotide polymorphism (SNP)-defined copy number alterations (CNAs), IGH/L plus TCR gene rearrangements and mutations in NRAS, KRAS, FLT3 and PTPN11 genes. We performed whole exome sequencing in one concordant twin pair. Potential 'driver' CNAs were low, 0-3 per case, and all were different within a pair. One patient had an NRAS mutation that was lacking from leukaemic cells of the twin sibling. By exome sequencing, there were 12 nonsynonymous mutations found in one twin and 5 in the other, one of which in SCL44A2 was shared or identical. Concordant pairs had some identical IGH/L and TCR rearrangements. In the twin pair with discordant hyperdiploid ALL, the healthy co-twin had persistent low level hyperdiploid CD19+ cells that lacked a CNA present in the ALL cells of her sibling. From these data, we propose that hyperdiploid ALL arises in a pre-B cell in utero and mutational changes necessary for clinical ALL accumulate subclonally and postnatally. PMID:24897505

  5. Creativity in Monozygotic and Dyzygotic Twins.

    ERIC Educational Resources Information Center

    Richmond, Bert O.

    The purpose of this study is to clarify further the relationships among creative, cognitive, and affective production of students. Thirteen pairs of twins, eight monozygotic (MZ), five dyzygotic (DZ), were administered the Torrance Tests of Creative Thinking, MMPI, and Revised Beta Examination. The F ratio for testing significance of within-set…

  6. Allergic colitis in monozygotic preterm twins.

    PubMed

    Baldassarre, Maria Elisabetta; Cappiello, Annarita; Laforgia, Nicola; Vanderhoof, Jon

    2013-02-01

    Allergic colitis (AC) typically develops in the first weeks or months of life and is characterized by the presence of red blood in the stools of healthy breastfed or formula fed infants. In this paper, we describe a case of rectal bleeding in monozygotic preterm twins that was resolved with the introduction of a cow's milk protein-free diet (CMPFD). The occurrence of this disorder in monozygotic twins raises the question as to whether the underlying abnormality in the immune regulation, which leads to poor acquisition of tolerance to cow's milk proteins, might be inherited or environmentally acquired. The case also highlights the use of the probiotic Lactobacillus GG (LGG) in the treatment of allergic colitis. PMID:23098248

  7. X-inactivation patterns in monozygotic and dizygotic female twins

    SciTech Connect

    Goodship, J.; Carter, J.; Burn, J.

    1996-01-22

    We have tested the hypothesis that contrasting X-inactivation patterns could be a trigger for monozygotic twinning in females. X-inactivation patterns were studied in umbilical cord tissue in 43 monozygotic twin pairs and 24 dizygotic twin pairs. Very skewed or non-random X-inactivation patterns were observed in both twins in six of the monozygotic twin pairs and in one of the dizygotic twin pairs. Contrasting X-inactivation patterns occurred in only one of the six monozygotic twin pairs. This does not support the original hypothesis. There is a trend to extreme skewing of X-inactivation pattern occurring more frequently in monozygotic twins. 21 refs., 1 fig., 2 tabs.

  8. Tourette syndrome: prediction of phenotypic variation in monozygotic twins by caudate nucleus D2 receptor binding.

    PubMed

    Wolf, S S; Jones, D W; Knable, M B; Gorey, J G; Lee, K S; Hyde, T M; Coppola, R; Weinberger, D R

    1996-08-30

    Tourette syndrome, a chronic tic disorder with autosomal dominant inheritance, exhibits considerable phenotypic variability even within monozygotic twin pairs. The origins of this variability remain unclear. Recent findings have implicated the caudate nucleus as a locus of pathology, and pharmacological evidence supports dopaminergic involvement. Within monozygotic twins discordant for Tourette syndrome severity, differences in D2 dopamine receptor binding in the head of the caudate nucleus predicted differences in phenotypic severity (r = 0.99); this relation was not observed in putamen. These data may link Tourette syndrome with a spectrum of neuropsychiatric disorders that involve associative striatal circuitry.

  9. Differences of DNA methylation profiles between monozygotic twins' blood samples.

    PubMed

    Li, Chengtao; Zhao, Shumin; Zhang, Na; Zhang, Suhua; Hou, Yiping

    2013-09-01

    Monozygotic twins (MZs) share an identical genomic sequence, which makes it impossible to discriminate one another with conventional genetic markers like STRs. On the other hand, phenotypic discordance between MZs implies the existence of different epigenetic characteristics. DNA methylation, an essential epigenetic modification, however, might be a potential biomarker to solve the forensic puzzle. In this study, we examined 22 pairs of MZs with a methylation BeadChip including 27,578 CpG sites. The results suggested that MZs exhibited remarkable differences of genome-wide 5-methylcytosine. According to a set of criteria of selection, 92 CpG sites with significant differences of methylation status within MZs were identified from the global epigenome. In conclusion, this pilot study suggested that CpG methylation profile could be a useful biomarker in individual identification of MZs. PMID:23649773

  10. Phenotypic variability in monozygotic twins with neurofibromatosis 2

    SciTech Connect

    Baser, M.E.; Ragge, N.K.; Riccardi, V.M.

    1996-09-06

    Mutations in the neurofibromatosis 2 (NF2) tumor suppressor gene on chromosome 22q12 cause a clinically variable autosomal dominant syndrome characterized by bilateral vestibular schwannomas (VSs), other nervous system tumors, and early onset lenticular cataracts. We studied three pairs of monozygotic (MZ) twins with NF2, all with bilateral VSs, to separate genetic from nongenetic causes of clinical variability. The evaluation included gadolinium-enhanced high-resolution magnetic resonance imaging of the head and spine, neuro-ophthalmic examination with slit lamp, physical examination, and zygosity testing with microsatellite markers. Each MZ pair was concordant for general phenotypic subtype (mild or severe) and often for the affected organ systems. However, the MZ pairs were discordant for some features of disease presentation or progression. For example, all three pairs were discordant for presence or type of associated cranial tumors. We hypothesize that phenotypic differences between NF2 MZ twins are at least partly due to stochastic processes, such as the loss of the second NF2 allele or alleles of other genes. 42 refs., 1 tab.

  11. Large Autosomal Copy-Number Differences within Unselected Monozygotic Twin Pairs are Rare.

    PubMed

    McRae, Allan F; Visscher, Peter M; Montgomery, Grant W; Martin, Nicholas G

    2015-02-01

    Monozygotic (MZ) twins form an important system for the study of biological plasticity in humans. While MZ twins are generally considered to be genetically identical, a number of studies have emerged that have demonstrated copy-number differences within a twin pair, particularly in those discordant for disease. The rate of autosomal copy-number variation (CNV) discordance within MZ twin pairs was investigated using a population sample of 376 twin pairs genotyped on Illumina Human610-Quad arrays. After CNV calling using both QuantiSNP and PennCNV followed by manual annotation, only a single CNV difference was observed within the MZ twin pairs, being a 130 KB duplication of chromosome 5. Five other potential discordant CNV were called by the software, but excluded based on manual annotation of the regions. It is concluded that large CNV discordance is rare within MZ twin pairs, indicating that any CNV difference found within phenotypically discordant MZ twin pairs has a high probability of containing the causal gene(s) involved. PMID:25578400

  12. The Use of Discordant MZ Twins to Generate Hypotheses regarding Non-Shared Environmental Influence on Anxiety in Middle Childhood

    ERIC Educational Resources Information Center

    Asbury, Kathryn; Dunn, Judy; Plomin, Robert

    2006-01-01

    Non-shared environmental influence (NSE) has been found to account for around 50 percent of anxiety variance, but specific NSE factors have not been identified. Discordant monozygotic (MZ) twins can be used to generate relevant hypotheses because MZ discordance can be caused by NSE, but not by genes or shared environment. Of 1590 MZ pairs teacher…

  13. Proton MRS in twin pairs discordant for schizophrenia.

    PubMed

    Lutkenhoff, E S; van Erp, T G; Thomas, M A; Therman, S; Manninen, M; Huttunen, M O; Kaprio, J; Lönnqvist, J; O'Neill, J; Cannon, T D

    2010-03-01

    Proton magnetic resonance spectroscopy ((1)H MRS) neurometabolite abnormalities have been detected widely in subjects with and at risk for schizophrenia. We hypothesized that such abnormalities would be present both in patients with schizophrenia and in their unaffected twin siblings. We acquired magnetic resonance spectra (TR/TE=3000/30 ms) at voxels in the mesial prefrontal gray matter, left prefrontal white matter and left hippocampus in 14 twin pairs discordant for schizophrenia (2 monozygotic, 12 dizygotic), 13 healthy twin pairs (4 monozygotic, 9 dizygotic) and 1 additional unaffected co-twin of a schizophrenia proband. In the mesial prefrontal gray matter voxel, N-acetylaspartate (NAA), creatine+phosphocreatine (Cr), glycerophosphocholine+phosphocholine (Cho) and myo-inositol (mI) did not differ significantly between patients with schizophrenia, their unaffected co-twins or healthy controls. However, glutamate (Glu) was significantly lower in patients with schizophrenia (31%, percent difference) and unaffected co-twins (21%) than in healthy controls (collapsed across twin pairs). In the left hippocampus voxel, levels of NAA (23%), Cr (22%) and Cho (36%) were higher in schizophrenia patients compared with controls. Hippocampal NAA (25%), Cr (22%) and Cho (37%) were also significantly higher in patients than in their unaffected co-twins. Region-to-region differences in metabolite levels were also notable within all three diagnosis groups. These findings suggest that (1)H MRS neurometabolite abnormalities are present not only in patients with schizophrenia, but also in their unaffected co-twins. Thus, reduced mesial prefrontal cortical Glu and elevated hippocampal NAA, Cr and Cho may represent trait markers of schizophrenia risk and, when exacerbated, state markers of schizophrenia itself. PMID:18645571

  14. Twin Legacies: Victor and Vincent McKusick/Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell-Silver Syndrome; Twins' Language Skills/Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins.

    PubMed

    Segal, Nancy L

    2016-04-01

    The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the 'Father of Medical Genetics', while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell-Silver Syndrome (RSS) and a study of twins' language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO. PMID:26934824

  15. Twin Legacies: Victor and Vincent McKusick/Twin Studies: Twinning Rates I; Twinning Rates II; MZ Twin Discordance for Russell-Silver Syndrome; Twins' Language Skills/Headlines: Babies Born to Identical Twin Couples; Identity Exchange; Death of Princess Ashraf (Twin); Yahoo CEO Delivers Identical Twins.

    PubMed

    Segal, Nancy L

    2016-04-01

    The lives of the illustrious monozygotic (MZ) twins, Victor A. and Vincent L. McKusick, are described. Victor earned the distinction as the 'Father of Medical Genetics', while Vincent was a legendary Chief Justice of the Maine Supreme Court. This dual biographical account is followed by two timely reports of twinning rates, a study of MZ twin discordance for Russell-Silver Syndrome (RSS) and a study of twins' language skills. Twin stories in the news include babies born to identical twin couples, a case of switched identity, the death of Princess Ashraf (Twin) and a new mother of twins who is also Yahoo's CEO.

  16. Asthma discordance in twins is linked to epigenetic modifications of T cells.

    PubMed

    Runyon, R Scott; Cachola, Leslie M; Rajeshuni, Nitya; Hunter, Tessa; Garcia, Marco; Ahn, Regina; Lurmann, Fred; Krasnow, Ruth; Jack, Lisa M; Miller, Rachel L; Swan, Gary E; Kohli, Arunima; Jacobson, Amanda C; Nadeau, Kari C

    2012-01-01

    T cells mediate the inflammatory responses observed in asthma among genetically susceptible individuals and have been suspected to be prone to epigenetic regulation. However, these relationships are not well established from past clinical studies that have had limited capacity to control for the effects of variable genetic predisposition and early environmental exposures. Relying on a cohort of monozygotic twins discordant for asthma we sought to determine if epigenetic modifications in T cells were associated with current asthma and explored whether such modifications were associated with second hand smoke exposures. Our study was conducted in a monozygotic twin cohort of adult twin pairs (n = 21) all discordant for asthma. Regulatory T cell (Treg) and effector T cell (Teff) subsets were assessed for levels of cellular function, protein expression, gene expression and CpG methylation within Forkhead box P3 (FOXP3) and interferon gamma-γ (IFNγ) loci. Comparisons by asthma and current report of exposure to second hand smoke were made. Treg from asthmatic discordant twins demonstrated decreased FOXP3 protein expression and impaired Treg function that was associated with increased levels of CpG methylation within the FOXP3 locus when compared to their non-asthmatic twin partner. In parallel, Teff from discordant asthmatic twins demonstrated increased methylation of the IFNγ locus, decreased IFNγ expression and reduced Teff function when compared to Teff from the non-asthmatic twin. Finally, report of current exposure to second hand smoke was associated with modifications in both Treg and Teff at the transcriptional level among asthmatics. The results of the current study provide evidence for differential function of T cell subsets in monozygotic twins discordant for asthma that are regulated by changes in DNA methylation. Our preliminary data suggest exposure to second hand smoke may augment the modified T cell responses associated with asthma. PMID:23226205

  17. Monozygotic VS. Dizygotic Twin Behavior in Artificial Mouse Twins

    PubMed Central

    Baunack, E.; Falk, U.; Gärtner, K.

    1984-01-01

    Adult inbred mice of an isogenic strain (AKR/NHan or C57BL/6J Han) differ in social (sexual and agonistic), emotional and psychomotoric behavior, depending on the kind of manipulation to which they were subjected at an early ontogenetic stage. Monozygotic twins (MZT) from eight-cell stages halved and transferred to uterine foster mothers were compared with dizygotic twins (DZT) from nonreduced but transferred eight-cell stages and with naturally born animals (NBA). Generally, early embryonic conditions predict the behavioral characteristics of the adult animals to a high degree. The MZT are motorially less active, less emotional, less aggressive and less socially interested than DZT and NBA. In tests of spontaneous social behavior (allogrooming, anogenital licking, mounting, fighting), as well as in tests for emotionality (open field: crossed fields and defecation), these behavioral patterns occurred less frequently in MZT than in DZT; the NBA were mostly intermediate. The copulatory pattern of male MZT differs from that of male DZT by a shortage of intromission latency and duration; furthermore, MZT pairs do not build up a steady rank order in competitive copulation tests, as opposed to DZT and NBA pairs. In a test for psychomotoric behavior (swimming), the MZT prefer "floating" as a survival strategy, wheras the DZT and NBA prefer "adult swimming." Therefore, it can be concluded that these behavioral differences may be caused by the particular psychosocial environment in which the twins grow up or may be due to early prenatal peculiarities, such as inadequate synchronization of the developmental status of uterus and embryo. PMID:6538528

  18. College-age twins: university admission policies / twin research: birth weight and neuromotor performance; transfusion syndrome markers; vanishing twins and fetal sex determination; mz twin discordance for wilson's disease / media: big at birth; planned separation of conjoined twins; x factor twins; Cinema: the identical.

    PubMed

    Segal, Nancy L

    2014-12-01

    There is a lack of research findings addressing the unique college admissions issues faced by twins and other multiples. The advantages and disadvantage twins face, as reported by college administrators, twins and families are reviewed. Next, recent research addressing twins' birth weight and neuromotor performance, transfusion syndrome markers, the vanishing twin syndrome and monozygotic (MZ) twin discordance for Wilson's disease is described. News items concerning the birth of unusually large twins, the planned separation of conjoined twins, twin participants in the X Factor games and a film, The Identical, are also summarized.

  19. College-age twins: university admission policies / twin research: birth weight and neuromotor performance; transfusion syndrome markers; vanishing twins and fetal sex determination; mz twin discordance for wilson's disease / media: big at birth; planned separation of conjoined twins; x factor twins; Cinema: the identical.

    PubMed

    Segal, Nancy L

    2014-12-01

    There is a lack of research findings addressing the unique college admissions issues faced by twins and other multiples. The advantages and disadvantage twins face, as reported by college administrators, twins and families are reviewed. Next, recent research addressing twins' birth weight and neuromotor performance, transfusion syndrome markers, the vanishing twin syndrome and monozygotic (MZ) twin discordance for Wilson's disease is described. News items concerning the birth of unusually large twins, the planned separation of conjoined twins, twin participants in the X Factor games and a film, The Identical, are also summarized. PMID:25331364

  20. Motor development of autistic monozygotic twins: a case study.

    PubMed

    Geddes, D

    1977-08-01

    A pair of autistic monozygotic twins were assessed on relevant portions of the Geddes Psychomotor Inventory. Over-all motor development of the 3-yr., 6-mo. old twins was similar and considered a partial consequence of the same genotype and comparable environmental experiences from birth. The twins exhibited poor or unsuccessful performance on tasks requiring abilities in language, communication, and appropriate relationships to objects; superior performance on specific fine manual motor skills, walking balance board, and climbing; at-age performance on tasks which were considered measures of patterned gross movement, balance, postural maintenance, and spatial orientation; and few typical autistic motor characteristics.

  1. Unilateral primary pulmonary agenesis and hypoplasia in monozygotic twins.

    PubMed

    Alsaadi, Muslim; Al Muqhem, Badr; Boukai, A; Iqbal, Shaikh M

    2012-01-01

    We describe 10-month-old identical female twin infants, one with primary left-sided pulmonary agenesis and the other with primary left-sided pulmonary hypoplasia. They came to our outpatient clinic complaining of persistent dry cough. The clinical examination revealed decreased air entry over the left hemithorax. Chest x-rays showed complete left-sided radio-opacity in both the twins. The chest computed tomography scan with contrast confirmed the diagnoses of left-sided pulmonary agenesis (twin A) and left-sided hypoplasia (twin B). No other associated congenital anomaly was noted in either of the twins. To our knowledge, such a condition in live monozygotic twins has not been previously reported in published studies. PMID:22156648

  2. Identical twin discordance for the Brachmann-de Lange syndrome revisited

    SciTech Connect

    Carakushansky, G.; Goncalves, M.R.; Kahn, E.

    1996-06-14

    The only known twin pair evidently discordantly affected for the BDLS (Brachmann-de Lange syndrome) and who had been considered monozygotic (MZ) based on blood analysis remained a problem because biological zygosity determination needed further typing. In this report we review the clinical findings of this pair of twins at the age of 20. The use of DNA fingerprinting with three multilocus probes, F10, DNT24, and 33.6, allowed us to present evidence of monozygosity with a high degree of certainty. The significance of this confirmation of discordance in determining the cause of BDLS is discussed. Intensive comparative genomic studies of the discordant twin sisters may be useful to unravel the molecular genetics of this enigmatic pattern of malformation. 21 refs., 2 figs.

  3. Bidirectional Influences between Maternal Parenting and Children's Peer Problems: A Longitudinal Monozygotic Twin Difference Study

    ERIC Educational Resources Information Center

    Yamagata, Shinji; Takahashi, Yusuke; Ozaki, Koken; Fujisawa, Keiko K.; Nonaka, Koichi; Ando, Juko

    2013-01-01

    This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin…

  4. Intersection of genetics and epigenetics in monozygotic twin genomes.

    PubMed

    Kim, Kwoneel; Lee, Kibaick; Bang, Hyoeun; Kim, Jeong Yeon; Choi, Jung Kyoon

    2016-06-01

    As a final function of various epigenetic mechanisms, chromatin regulation is a transcription control process that especially demonstrates active interaction with genetic elements. Thus, chromatin structure has become a principal focus in recent genomics researches that strive to characterize regulatory functions of DNA variants related to diseases or other traits. Although researchers have been focusing on DNA methylation when studying monozygotic (MZ) twins, a great model in epigenetics research, interactions between genetics and epigenetics in chromatin level are expected to be an imperative research trend in the future. In this review, we discuss how the genome, epigenome, and transcriptome of MZ twins can be studied in an integrative manner from this perspective.

  5. Using epigenomic studies in monozygotic twins to improve our understanding of cancer.

    PubMed

    Roos, Leonie; Spector, Timothy D; Bell, Christopher G

    2014-06-01

    Cancer is a set of diseases that exhibit not only genetic mutations but also a profoundly distorted epigenetic landscape. Over the last two decades, great advances have been made in identifying these alterations and their importance in the initiation and progression of cancer. Epigenetic changes can be seen from the very early stages in tumorigenesis and dysregulation of the epigenome has an increasingly acknowledged pathogenic role. Epigenomic twin studies have great potential to contribute to our understanding of complex diseases, such as cancer. This is because the use of monozygotic twins discordant for cancer enables epigenetic variation analysis without the confounding influence of the constitutive genetic background, age or cohort effects. It therefore allows the identification of susceptibility loci that may be sensitive to modification by the environment. These studies into cancer etiology will potentially lead to robust epigenetic markers for the detection and risk assessment of cancer.

  6. Monozygotic twins of different apparent sex

    SciTech Connect

    Yokota, Yukifumi; Fujino, Nobuyuki; Sato, Yoshiaki; Matsunobu, Akira; Tadokoro, Mamoru; Akane, Atsushi; Matsuura, Nobuo; Maeda, Tohru; Nakahori, Yutaka; Nakagome, Yasuo

    1994-10-15

    We report on twins of unlike sex who shared a 45,X/46,X, +mar karyotype. The mar chromosome was found to be Yq- by DNA analysis. Marker studies, including 8 VNTR loci, yielded a probability of monozygosity of 0.99999996. 16 refs., 1 fig., 1 tab.

  7. Traces of embryogenesis are the same in monozygotic and dizygotic twins: not compatible with double ovulation

    PubMed Central

    Boklage, Charles E.

    2009-01-01

    Common knowledge of over a century has it that monozygotic and dizygotic twinning events occur by unrelated mechanisms: monozygotic twinning ‘splits’ embryos, producing anomalously re-arranged embryogenic asymmetries; dizygotic twinning begins with independent ovulations yielding undisturbed parallel embryogeneses with no expectation of departures from singleton outcomes. The anomalies statistically associated with twin births are due to the re-arranged embryos of the monozygotics. Common knowledge further requires that dizygotic pairs are dichorionic; monochorionicity is exclusive to monozygotic pairs. These are fundamental certainties in the literature of twin biology. Multiple observations contradict those common knowledge understandings. The double ovulation hypothesis of dizygotic twinning is untenable. Girl–boy twins differ subtly from all other humans of either sex, absolutely not representative of all dizygotics. Embryogenesis of dizygotic twins differs from singleton development at least as much as monozygotic embryogenesis does, and in the same ways, and the differences between singletons and twins of both zygosities represent a coherent system of re-arranged embryogenic asymmetries. Dizygotic twinning and monozygotic twinning have the same list of consequences of anomalous embryogenesis. Those include an unignorable fraction of dizygotic pairs that are in fact monochorionic, plus many more sharing co-twins’ cells in tissues other than a common chorion. The idea that monozygotic and dizygotic twinning events arise from the same embryogenic mechanism is the only plausible hypothesis that might explain all of the observations. PMID:19252194

  8. Synesthesia in twins: incomplete concordance in monozygotes suggests extragenic factors.

    PubMed

    Bosley, Hannah G; Eagleman, David M

    2015-06-01

    Colored-sequence synesthesia (CSS) is a neurological condition in which sequential stimuli such as letters, numbers, or days of the week trigger simultaneous, involuntary color perception. Although the condition appears to run in families and several studies have sought a genetic link, the genetic contribution to synesthesia remains unclear. We conducted the first comparative twin study of CSS and found that CSS has a pairwise concordance of 73.9% in monozygotic twins, and a pairwise concordance of 36.4% in dizygotic twins. In line with previous studies, our results suggest a heritable element of synesthesia. However, consonant with the findings of previous single-pair case studies, our large sample size verifies that synesthesia is not completely conferred by genetics; if it were, monozygotic twins should have 100% concordance. These findings implicate a genetic mechanism of CSS that may work differently than previously thought: collectively, our data suggest that synesthesia is a heritable condition with incomplete penetrance that is substantially influenced by epigenetic and environmental factors.

  9. Synesthesia in twins: incomplete concordance in monozygotes suggests extragenic factors.

    PubMed

    Bosley, Hannah G; Eagleman, David M

    2015-06-01

    Colored-sequence synesthesia (CSS) is a neurological condition in which sequential stimuli such as letters, numbers, or days of the week trigger simultaneous, involuntary color perception. Although the condition appears to run in families and several studies have sought a genetic link, the genetic contribution to synesthesia remains unclear. We conducted the first comparative twin study of CSS and found that CSS has a pairwise concordance of 73.9% in monozygotic twins, and a pairwise concordance of 36.4% in dizygotic twins. In line with previous studies, our results suggest a heritable element of synesthesia. However, consonant with the findings of previous single-pair case studies, our large sample size verifies that synesthesia is not completely conferred by genetics; if it were, monozygotic twins should have 100% concordance. These findings implicate a genetic mechanism of CSS that may work differently than previously thought: collectively, our data suggest that synesthesia is a heritable condition with incomplete penetrance that is substantially influenced by epigenetic and environmental factors. PMID:25704836

  10. Influence of cardiorespiratory fitness on PPARG mRNA expression using monozygotic twin case control.

    PubMed

    Queiroga, Marcos Roberto; Barbieri, Ricardo Augusto; Ferreira, Sandra Aires; Luchessi, André Ducati; Hirata, Rosario Dominguez Crespo; Hirata, Mario Hiroyuki; Kokubun, Eduardo

    2015-01-01

    The influence of cardiorespiratory fitness (VO2max) on anthropometric variables and PPARG mRNA expression was investigated. Monozygotic twin pairs aged 11-18 years were grouped into discordant (D) and concordant (C) high and low VO2max groups. VO2max was determined by progressive maximal exercise test on treadmill with gas exchange analysis. Body mass (BM), BMI, waist circumference (WC), triceps (TR), and subscapular (SB) skinfold thicknesses were measured. Twins from the discordant group had differences in VO2max values (D-high = 45.9 ± 10.0 versus D-low = 32.4 ± 10.6 mL·kg(-1)·min(-1), P = 0.025), while no differences were found in the concordant group (C-high = 42.4 ± 9.2 versus C-low = 38.8 ± 9.8 mL·kg(-1)·min(-1), P = 0.952). In discordant group, VO2max was negatively correlated with TR + SB (r = -0.540, P = 0.021) and positively correlated with PPARG expression in leukocytes (r = 0.952, P = 0.001). Moreover, PPARG expression was directly correlated with BM (r = 0.714, P = 0.047) and height (r = 0.762, P = 0.028). In concordant twins, VO2max was inversely correlated with BM (r = -0.290, P = 0.027), BMI (r = -0.472, P = 0.001), WC (r = -0.426, P = 0.001), and TR + SB (r = -0.739, P = 0.001). Twins D-high had 1.78-fold greater PPARG expression when compared with twins D-low (P = 0.048). In conclusion, the cardiorespiratory fitness may modulate PPARG expression in childhood and adolescence, independently of the genetic background. PMID:25879043

  11. Influence of Cardiorespiratory Fitness on PPARG mRNA Expression Using Monozygotic Twin Case Control

    PubMed Central

    Queiroga, Marcos Roberto; Barbieri, Ricardo Augusto; Ferreira, Sandra Aires; Luchessi, André Ducati; Hirata, Rosario Dominguez Crespo; Hirata, Mario Hiroyuki; Kokubun, Eduardo

    2015-01-01

    The influence of cardiorespiratory fitness (VO2max) on anthropometric variables and PPARG mRNA expression was investigated. Monozygotic twin pairs aged 11–18 years were grouped into discordant (D) and concordant (C) high and low VO2max groups. VO2max was determined by progressive maximal exercise test on treadmill with gas exchange analysis. Body mass (BM), BMI, waist circumference (WC), triceps (TR), and subscapular (SB) skinfold thicknesses were measured. Twins from the discordant group had differences in VO2max values (D-high = 45.9 ± 10.0 versus D-low = 32.4 ± 10.6 mL·kg−1·min−1, P = 0.025), while no differences were found in the concordant group (C-high = 42.4 ± 9.2 versus C-low = 38.8 ± 9.8 mL·kg−1·min−1, P = 0.952). In discordant group, VO2max was negatively correlated with TR + SB (r = −0.540, P = 0.021) and positively correlated with PPARG expression in leukocytes (r = 0.952, P = 0.001). Moreover, PPARG expression was directly correlated with BM (r = 0.714, P = 0.047) and height (r = 0.762, P = 0.028). In concordant twins, VO2max was inversely correlated with BM (r = −0.290, P = 0.027), BMI (r = −0.472, P = 0.001), WC (r = −0.426, P = 0.001), and TR + SB (r = −0.739, P = 0.001). Twins D-high had 1.78-fold greater PPARG expression when compared with twins D-low (P = 0.048). In conclusion, the cardiorespiratory fitness may modulate PPARG expression in childhood and adolescence, independently of the genetic background. PMID:25879043

  12. [Refsum syndrome in a pair of monozygotic twins].

    PubMed

    Kohnen, S; Hammerstein, W

    1993-10-01

    We report the case of a pair of twins with the ophthalmological and functional findings of Refsum syndrome. The twins were monozygotic twin brothers whose ophthalmological symptoms were noticed when they were in their forties. The diagnosis in the first brother led to a search for findings in the second. It was possible to attribute the non-specific subjective complaints to this as yet unknown syndrome. No causal therapy can be offered the patients. However, knowledge of the biochemical basis of the disease makes it possible to treat it by means of diet. In patients with retinopathia pigmentosa, an attempt should be made to identify Refsum syndrome if neurological symptoms are found in addition.

  13. Monozygotic twins affected with major depressive disorder have greater variance in methylation than their unaffected co-twin.

    PubMed

    Byrne, E M; Carrillo-Roa, T; Henders, A K; Bowdler, L; McRae, A F; Heath, A C; Martin, N G; Montgomery, G W; Krause, L; Wray, N R

    2013-01-01

    Our understanding of major depressive disorder (MDD) has focused on the influence of genetic variation and environmental risk factors. Growing evidence suggests the additional role of epigenetic mechanisms influencing susceptibility for complex traits. DNA sequence within discordant monozygotic twin (MZT) pairs is virtually identical; thus, they represent a powerful design for studying the contribution of epigenetic factors to disease liability. The aim of this study was to investigate whether specific methylation profiles in white blood cells could contribute to the aetiology of MDD. Participants were drawn from the Queensland Twin Registry and comprised 12 MZT pairs discordant for MDD and 12 MZT pairs concordant for no MDD and low neuroticism. Bisulphite treatment and genome-wide interrogation of differentially methylated CpG sites using the Illumina Human Methylation 450 BeadChip were performed in WBC-derived DNA. No overall difference in mean global methylation between cases and their unaffected co-twins was found; however, the differences in females was significant (P=0.005). The difference in variance across all probes between affected and unaffected twins was highly significant (P<2.2 × 10⁻¹⁶), with 52.4% of probes having higher variance in cases (binomial P-value<2.2 × 10⁻¹⁶). No significant differences in methylation were observed between discordant MZT pairs and their matched concordant MZT (permutation minimum P=0.11) at any individual probe. Larger samples are likely to be needed to identify true associations between methylation differences at specific CpG sites. PMID:23756378

  14. Lesch-Nyhan disease in a female with a clinically normal monozygotic twin.

    PubMed

    De Gregorio, Laura; Jinnah, H A; Harris, James C; Nyhan, William L; Schretlen, David J; Trombley, Lucy M; O'Neill, J Patrick

    2005-05-01

    Lesch-Nyhan disease (LND) is an inborn error of purine metabolism caused by defective activity of the enzyme hypoxanthine guanine phosphoribosyl transferase (HPRT, EC 2.4.2.8), resulting from mutation in the corresponding gene on the long arm of the X chromosome (Xq26). The classic phenotype occurs almost exclusively in males and is characterized by hyperuricemia, mental retardation, severe dystonia, and self-injurious behavior. Heterozygous carrier females are usually clinically normal. However, a small number of clinically affected females have been described. In all previous cases there was a mutation in one HPRT allele and non-random inactivation of the X chromosome carrying the normal HPRT gene. We have analyzed a female MZ twin pair discordant for Lesch-Nyhan disease. The mother and both twins are heterozygous carriers of a HPRT splicing mutation (IVS8 + 4A > G; c.609 + 4A > G) and all three express the mutant allele at similar frequencies in peripheral blood T cells. The mother and one sister are clinically normal. In the affected twin, the clinical phenotype is classical for Lesch-Nyhan disease, despite the fact that HPRT activity in the blood was also normal. X inactivation analysis showed a skewed pattern in the fibroblasts of the affected twin sister, with the X chromosome carrying the normal HPRT allele preferentially inactivated. As in many other reported cases of X-linked diseases, the discordant phenotype of the two monozygous twin sisters suggests that the process responsible for monozygotic twinning can trigger skewed X inactivation.

  15. DNA-Methylation Patterns in Trisomy 21 Using Cells from Monozygotic Twins

    PubMed Central

    Sailani, M. Reza; Santoni, Federico A.; Letourneau, Audrey; Borel, Christelle; Makrythanasis, Periklis; Hibaoui, Youssef; Popadin, Konstantin; Bonilla, Ximena; Guipponi, Michel; Gehrig, Corinne; Vannier, Anne; Carre-Pigeon, Frederique; Feki, Anis; Nizetic, Dean; Antonarakis, Stylianos E.

    2015-01-01

    DNA methylation is essential in mammalian development. We have hypothesized that methylation differences induced by trisomy 21 (T21) contribute to the phenotypic characteristics and heterogeneity in Down syndrome (DS). In order to determine the methylation differences in T21 without interference of the interindividual genomic variation, we have used fetal skin fibroblasts from monozygotic (MZ) twins discordant for T21. We also used skin fibroblasts from MZ twins concordant for T21, normal MZ twins without T21, and unrelated normal and T21 individuals. Reduced Representation Bisulfite Sequencing (RRBS) revealed 35 differentially methylated promoter regions (DMRs) (Absolute methylation differences = 25%, FDR < 0.001) in MZ twins discordant for T21 that have also been observed in comparison between unrelated normal and T21 individuals. The identified DMRs are enriched for genes involved in embryonic organ morphogenesis (FDR = 1.60 e -03) and include genes of the HOXB and HOXD clusters. These DMRs are maintained in iPS cells generated from this twin pair and are correlated with the gene expression changes. We have also observed an increase in DNA methylation level in the T21 methylome compared to the normal euploid methylome. This observation is concordant with the up regulation of DNA methyltransferase enzymes (DNMT3B and DNMT3L) and down regulation of DNA demethylation enzymes (TET2 and TET3) observed in the iPSC of the T21 versus normal twin. Altogether, the results of this study highlight the epigenetic effects of the extra chromosome 21 in T21 on loci outside of this chromosome that are relevant to DS associated phenotypes. PMID:26317209

  16. Speaking fundamental frequency in monozygotic and dizygotic twins.

    PubMed

    Debruyne, Frans; Decoster, Wivine; Van Gijsel, Annemie; Vercammen, Julie

    2002-12-01

    The speaking fundamental frequency (SFF) and the intraindividual variation of the SFF during the reading of a Dutch standard text were measured in 30 female monozygotic twins (MT) and 30 dizygotic twins (DT), aged 15-29 years. A control group was created that consisted of 30 nonrelated paired individuals of equal age. Studying the intrapair correlation coefficients it seemed that the SFF was similar to a greater degree in MT and to a lesser degree in DT, while there was no correlation at all in nonrelated peers. These results are compatible with a genetic basis for the SFF. On the other hand, the intraindividual variation of the SFF was highly similar in MT and in DT (but not in nonrelated peers), so that for this parameter it was not possible to discern the influences of genetic disposition and shared environment. PMID:12512633

  17. Heritability of thyroid peroxidase autoantibody levels in type 1 diabetes: evidence from discordant twin pairs

    PubMed Central

    Wang, Bin; Hawa, Mohammed I.; Rijsdijk, Frühling V.; Fain, Pamela R.; Paschou, Stavroula A.; Boehm, Bernhard O.; Steck, Andrea K.; Snieder, Harold

    2016-01-01

    Aims/hypothesis The discordance status of (autoimmune) type 1 diabetes within monozygotic twin pairs points to the importance of environmental factors. The aim of this study was to investigate whether the environmental events causing type 1 diabetes influence thyroid autoimmunity. Methods Monozygotic and dizygotic twins discordant for type 1 diabetes from the UK and USA were tested for thyroid peroxidase autoantibodies (TPOA) by radioimmunoassay. Using quantitative genetic model fitting of a liability-threshold model we estimated the contribution of genetic (heritability) and environmental factors to TPOA. Results TPOA positivity was higher in females than in males in both cohorts and was associated with later age at diagnosis in the UK and combined cohorts (p<0.01). TPOA did not specifically segregate with type 1 diabetes in the twin pairs (p>0.2 in all groups). The best-fitting models showed heritability (95% CI) estimates for TPOA of 63% (37%, 80%) for the UK and 80% (51%, 92%) for US twins, while the best-fitting meta-analysis model of the two twin cohorts combined included additive genetic and unique environmental factors with a heritability estimate of 69% (50%, 82%). Conclusions/interpretation Risk of thyroid autoimmunity, defined by TPOA, in the context of autoimmune diabetes is, substantially, genetically determined in discordant twin pairs. Environmental factors leading to type 1 diabetes were not the same as those involved with thyroid autoimmunity. It follows that it is as important to investigate for thyroid autoimmunity in relatives of type 1 diabetes patients as it is in the patients themselves. PMID:26070305

  18. Investigating Unique Environmental Influences of Parenting Practices on Youth Anxiety: A Monozygotic Twin Differences Study

    ERIC Educational Resources Information Center

    Chen, Jie; Yu, Jing; Zhang, Jianxin

    2016-01-01

    The associations between parenting practices and adolescent anxiety symptoms were examined in both individual and monozygotic (MZ) twin differences levels. Participants were 804 pairs of Chinese MZ adolescent twins aged 10-18 years (M = 13.57, SD = 2.67, 52% females). Twins' anxiety symptoms were assessed by self- and parent-reports. Twins also…

  19. Early onset alcohol use and self-harm: A discordant twin analysis

    PubMed Central

    Few, Lauren R.; Werner, Kimberly B.; Sartor, Carolyn E.; Trull, Timothy; Nock, Matthew K.; Bucholz, Kathleen K.; Deitz, Sarah K.; Glowinski, Anne L.; Martin, Nicholas G.; Nelson, Elliot C.; Statham, Dixie J.; Madden, Pamela A. F.; Heath, Andrew; Lynskey, Michael T.; Agrawal, Arpana

    2015-01-01

    Background Self-harm has considerable societal and economic costs and has been extensively studied in relation to alcohol involvement. Whereas early onset alcohol use (EAU) has been causally linked to maladaptive clinical outcomes, its association with self-harm is less well characterized. The current study aimed to further examine the link between EAU and both non-suicidal self-injury (NSSI) and suicide attempt (SA), and elucidate shared familial and causal/individual-specific pathways that explain this co-occurrence. Methods Using data from 6,082 Australian same-sex twin pairs (1,732 MZ and 1,309 DZ), ages 23-40, we examined prevalence rates of NSSI and SA among twin pairs concordant and discordant for EAU. Conditional logistic regression, controlling for early clinical covariates and the influence of zygosity on EAU, was used to examine the odds ratio (OR) of self-harm within twin pairs discordant for EAU. Results Prevalence rates of both NSSI and SA were highest among twin pairs concordant for EAU and for twins who reported EAU within discordant twin pairs. Results from discordant twin analyses revealed nearly four-fold increased odds of SA for the twin who endorsed EAU, and this OR was equal across monozygotic (MZ) and dizygotic (DZ) twins. EAU also was associated with elevated odds of NSSI (OR=7.62), although this was only the case for DZ twins in discordant pairs. Conclusions The equivalent increase in odds of SA for both MZ and DZ twins suggests that causal or individual-specific influences explain the link between EAU and SA. For NSSI, elevated odds for DZ twins and nonsignificant findings for MZ twins implicate correlated genetic factors in the association between EAU and NSSI. Future studies should test mechanisms through which EAU may causally influence SA, as well as examine whether genetic risk for third variables (e.g., negative urgency, stress reactivity) may explain the genetic overlap between EAU and NSSI. PMID:26463647

  20. Monochorionic dizygous twins presenting with blood chimerism and discordant sex.

    PubMed

    Smeets, Dominique; van Vugt, John M G; Gomes, Ingrid; van den Heuvel, Simone; van Heijst, Arno; Reuss, Annette; Claahsen-van der Grinten, Hedi L

    2013-08-01

    Monochorionic dizygous twins are probably more frequent than considered previously as many cases remain unrecognized, especially when the children have the same sex. Here we present a pair of dizygous, sex-discordant monochorionic twins who were conceived after artificial insemination. Histological examination of the placenta and extensive genetic studies of the healthy boy and girl clearly proved that they indeed were monochorionic dizygous twins with a fully joined blood circulation. We conclude that when counseling parents expecting monochorionic twins of discordant sex, not only a disorder of sexual differentiation in one of the twins should be addressed but also the possibility of dizygosity with a completely normal (sexual) development of both children.

  1. Statistical analyses of monozygotic and dizygotic twinning rates.

    PubMed

    Fellman, Johan

    2013-12-01

    The French mathematician Bertillon reasoned that the number of dizygotic (DZ) pairs would equal twice the number of twin pairs of unlike sexes. The remaining twin pairs in a sample would presumably be monozygotic (MZ). Weinberg restated this idea and the calculation has come to be known as Weinberg's differential rule (WDR). The keystone of WDR is that DZ twin pairs should be equally likely to be of the same or the opposite sex. Although the probability of a male birth is greater than .5, the reliability of WDR's assumptions has never been conclusively verified or rejected. Let the probability for an opposite-sex (OS) twin maternity be pO , for a same-sex (SS) twin maternity pS and, consequently, the probability for other maternities 1 - pS - pO . The parameter estimates $\\hat p_O$ and $\\hat p_S$ are relative frequencies. Applying WDR, the MZ rate is m = pS - pO and the DZ rate is d = 2pO , but the estimates $\\hat m$ and $\\hat d$ are not relative frequencies. The maximum likelihood estimators $\\hat p_S$ and $\\hat p_O$ are unbiased, efficient, and asymptotically normal. The linear transformations $\\hat m = \\hat p_S - \\hat p_O$ and ${\\skew6\\hat d} = 2\\hat p_O$ are efficient and asymptotically normal. If WDR holds they are also unbiased. For the tests of a set of m and d rates, contingency tables cannot be used. Alternative tests are presented and the models are applied on published data. PMID:24063661

  2. Monozygotic male twins concordant for Beckwith-Wiedemann syndrome

    SciTech Connect

    Clemens, M.; McPherson, E.; Sherer, C. |

    1994-09-01

    The Beckwith-Wiedemann syndrome (BWS) is a multiple congenital anomaly syndrome characterized by macrosomia, macro glossia, visceromegaly, characteristic facies, and in some cases omphalocele, hypoglycemia, hemihypertrophy, and risk of embryonal tumors. Most cases occur sporadically in chromosomally normal individuals, but a few BWS patients have anomalies of 11p and others have evidence of microduplications or paternal isodisomy in this region. In some families with autosomal dominant transmission, BWS maps to 11p15.5, but the mechanism of transmission is not fully understood. BWS has been reported in 11 sets of MZ twins, including 10 female pairs (9 discordant and 1 partially concordant) and one male pair concordant for both BWS & dup 15q11.2-q13. We report a pair of premature male MZ twins with macroglossia, postnatal overgrowth, characteristic BWS facies, and mild developmental delay. One twin had hypoglycemia, but neither had omphalocele or hemihypertrophy and serial abdominal ultrasounds have been normal. DNA fingerprinting confirmed monozygosity. Chromosome studies showed a marker 11p14.2 in one twin only, and molecular genetic studies of the 11p15.5 region showed no evidence of duplication or isodisomy in either twin.

  3. A Monozygotic Twin Difference Study of Friends' Aggression and Children's Adjustment Problems

    ERIC Educational Resources Information Center

    Vitaro, Frank; Brendgen, Mara; Boivin, Michel; Cantin, Stephane; Dionne, Ginette; Tremblay, Richard E.; Girard, Alain; Perusse, Daniel

    2011-01-01

    This study used the monozygotic (MZ) twin difference method to examine whether differences in friends' aggression increased the differences in MZ twins' aggression and depressive symptoms from kindergarten to Grade 1 and whether perceived victimization by the friend played a mediating role in this context. Participants were 223 MZ twin pairs.…

  4. Langerhans cell histiocytosis in monozygotic twins with central diabetes insipidus and hypophyseal masses

    PubMed Central

    Wei, Sung-Tai; Chen, Der-Cherng; Cho, Der-Yang; Lin, Hung-Lin

    2015-01-01

    Langerhans cell histiocytosis (LCH) is a systemic disease mainly affecting children and young adults. It can manifest as single system disorder or multi-system involvement. When the central nervous system is involved, the hypothalamic–pituitary axis is the most common location affected. Herein we report a rare case of Langerhans cell histiocytosis in monozygotic twins both with central diabetes and hypophyseal masses. This is the first report about LCH in monozygotic twins with hypophyseal lesions. PMID:25972939

  5. The first case of genetically confirmed monozygotic twinning in the dog.

    PubMed

    Joonè, C J; De Cramer, Kgm; Nöthling, J O

    2016-10-01

    Monozygotic twinning has not previously been genetically confirmed in the dog. This case report describes the finding of two viable male monozygotic foetuses within one placental site during caesarean section. Their umbilical cords attached to a single placenta. Genetic profiling using a total of 38 microsatellite markers, as well as amelogenin and SRY for sex determination, revealed identical DNA profiles, whether derived from blood or tissue (buccal swabs) samples. To the best of our knowledge, this is the first report of monozygotic twinning in the dog confirmed using DNA profiling. PMID:27545903

  6. Gene expression differences in skin fibroblasts in identical twins discordant for type 1 diabetes.

    PubMed

    Caramori, M Luiza; Kim, Youngki; Moore, Jason H; Rich, Stephen S; Mychaleckyj, Josyf C; Kikyo, Nobuaki; Mauer, Michael

    2012-03-01

    Clinical studies suggest metabolic memory to hyperglycemia. We tested whether diabetes leads to persistent systematic in vitro gene expression alterations in patients with type 1 diabetes (T1D) compared with their monozygotic, nondiabetic twins. Microarray gene expression was determined in skin fibroblasts (SFs) of five twin pairs cultured in high glucose (HG) for ∼6 weeks. The Exploratory Visual Analysis System tested group differences in gene expression levels within KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways. An overabundance of differentially expressed genes was found in eight pathways: arachidonic acid metabolism (P = 0.003849), transforming growth factor-β signaling (P = 0.009167), glutathione metabolism (P = 0.01281), glycosylphosphatidylinositol anchor (P = 0.01949), adherens junction (P = 0.03134), dorsal-ventral axis formation (P = 0.03695), proteasome (P = 0.04327), and complement and coagulation cascade (P = 0.04666). Several genes involved in epigenetic mechanisms were also differentially expressed. All differentially expressed pathways and all the epigenetically relevant differentially expressed genes have previously been related to HG in vitro or to diabetes and its complications in animal and human studies. However, this is the first in vitro study demonstrating diabetes-relevant gene expression differences between T1D-discordant identical twins. These SF gene expression differences, persistent despite the HG in vitro conditions, likely reflect "metabolic memory", and discordant identical twins thus represent an excellent model for studying diabetic epigenetic processes in humans. PMID:22315306

  7. Aging as accelerated accumulation of somatic variants: whole-genome sequencing of centenarian and middle-aged monozygotic twin pairs.

    PubMed

    Ye, Kai; Beekman, Marian; Lameijer, Eric-Wubbo; Zhang, Yanju; Moed, Matthijs H; van den Akker, Erik B; Deelen, Joris; Houwing-Duistermaat, Jeanine J; Kremer, Dennis; Anvar, Seyed Yahya; Laros, Jeroen F J; Jones, David; Raine, Keiran; Blackburne, Ben; Potluri, Shobha; Long, Quan; Guryev, Victor; van der Breggen, Ruud; Westendorp, Rudi G J; 't Hoen, Peter A C; den Dunnen, Johan; van Ommen, Gert Jan B; Willemsen, Gonneke; Pitts, Steven J; Cox, David R; Ning, Zemin; Boomsma, Dorret I; Slagboom, P Eline

    2013-12-01

    It has been postulated that aging is the consequence of an accelerated accumulation of somatic DNA mutations and that subsequent errors in the primary structure of proteins ultimately reach levels sufficient to affect organismal functions. The technical limitations of detecting somatic changes and the lack of insight about the minimum level of erroneous proteins to cause an error catastrophe hampered any firm conclusions on these theories. In this study, we sequenced the whole genome of DNA in whole blood of two pairs of monozygotic (MZ) twins, 40 and 100 years old, by two independent next-generation sequencing (NGS) platforms (Illumina and Complete Genomics). Potentially discordant single-base substitutions supported by both platforms were validated extensively by Sanger, Roche 454, and Ion Torrent sequencing. We demonstrate that the genomes of the two twin pairs are germ-line identical between co-twins, and that the genomes of the 100-year-old MZ twins are discerned by eight confirmed somatic single-base substitutions, five of which are within introns. Putative somatic variation between the 40-year-old twins was not confirmed in the validation phase. We conclude from this systematic effort that by using two independent NGS platforms, somatic single nucleotide substitutions can be detected, and that a century of life did not result in a large number of detectable somatic mutations in blood. The low number of somatic variants observed by using two NGS platforms might provide a framework for detecting disease-related somatic variants in phenotypically discordant MZ twins. PMID:24182360

  8. Labeling of Chromosomes in Cell Development and the Appearance of Monozygotic Twins

    PubMed Central

    Jim, Carol; Berkovich, Simon

    2015-01-01

    Understanding the mechanism behind the structure of the internal cellular clock can lead to advances in the knowledge of origins of pairs of monozygotic twins and higher order multiples as well as other biological phenomena. To gain insight into this mechanism, we analyze possible cell labeling schemes that model an organism's development. Our findings lead us to predict that monozygotic quadruplets are not quadruplets in the traditional sense but rather two pairs of monozygotic twins where the pairs slightly differ—a situation we coin quadruplet twins. From the considered model, the probability of monozygotic twins is found to be (1/2)K, and we discover that the probability of monozygotic quadruplets, or triplets as in the case of the death of an embryo, is (1/8)K, where K is a species-specific integer representing the number of pairs of homologous chromosomes. The parameter K may determine cancerization with a probability threshold that is approximately inversely proportional to the Hayflick limit. Exposure to some cancerization factors such as small levels of ionizing radiation and chemical pollution may not produce cancer. PMID:26185760

  9. De novo and inherited CNVs in MZ twin pairs selected for discordance and concordance on Attention Problems.

    PubMed

    Ehli, Erik A; Abdellaoui, Abdel; Hu, Yueshan; Hottenga, Jouke Jan; Kattenberg, Mathijs; van Beijsterveldt, Toos; Bartels, Meike; Althoff, Robert R; Xiao, Xiangjun; Scheet, Paul; de Geus, Eco J; Hudziak, James J; Boomsma, Dorret I; Davies, Gareth E

    2012-10-01

    Copy number variations (CNVs) have been reported to be causal suspects in a variety of psychopathologic traits. We investigate whether de novo and/or inherited CNVs contribute to the risk for Attention Problems (APs) in children. Based on longitudinal phenotyping, 50 concordant and discordant monozygotic (MZ) twin pairs were selected from a sample of ∼3200 MZ pairs. Two types of de novo CNVs were investigated: (1) CNVs shared by both MZ twins, but not inherited (pre-twinning de novo CNVs), which were detected by comparing copy number (CN) calls between parents and twins and (2) CNVs not shared by co-twins (post-twinning de novo CNVs), which were investigated by comparing the CN calls within MZ pairs. The association between the overall CNV burden and AP was also investigated for CNVs genome-wide, CNVs within genes and CNVs outside of genes. Two de novo CNVs were identified and validated using quantitative PCR: a pre-twinning de novo duplication in a concordant-unaffected twin pair and a post-twinning deletion in the higher scoring twin from a concordant-affected pair. For the overall CNV burden analyses, affected individuals had significantly larger CNVs that overlapped with genes than unaffected individuals (P=0.008). This study suggests that the presence of larger CNVs may increase the risk for AP, because they are more likely to affect genes, and confirms that MZ twins are not always genetically identical. PMID:22490988

  10. Dietary Intake at 9 Years and Subsequent Body Mass Index in Adolescent Boys and Girls: A Study of Monozygotic Twin Pairs.

    PubMed

    Dubois, Lise; Diasparra, Maikol; Bogl, Leonie-Helen; Fontaine-Bisson, Bénédicte; Bédard, Brigitte; Tremblay, Richard E; Kaprio, Jaakko; Boivin, Michel

    2016-02-01

    There is a lack of evidence pointing to specific dietary elements related to weight gain and obesity prevention in childhood and adulthood. Dietary intake and obesity are both inherited and culturally transmitted, but most prospective studies on the association between diet and weight status do not take genetics into consideration. The objective of this study was to document the association between dietary intake at 9 years and subsequent Body Mass Index (BMI) in adolescent monozygotic boy and girl twin pairs. This research used data from 152 twin pairs. Dietary data were collected from two 24-hour-recall interviews with a parent and the child aged 9 years. Height and weight were obtained when the twins were aged 9, 12, 13, and 14 years. Intrapair variability analysis was performed to identify dietary elements related to BMI changes in subsequent years. BMI-discordant monozygotic twin pairs were also identified to analyze the dietary constituents that may have generated the discordance. After eliminating potential confounding genetic factors, pre-adolescent boys who ate fewer grain products and fruit and consumed more high-fat meat and milk had higher BMIs during adolescence; pre-adolescent girls who consumed more grain products and high-fat meat and milk had higher BMIs during adolescence. Energy intake (EI) at 9 years was not related to BMI in subsequent years. Our study suggests that messages and interventions directed at obesity prevention could take advantage of sex-specific designs and' eventually' genetic information.

  11. Dietary Intake at 9 Years and Subsequent Body Mass Index in Adolescent Boys and Girls: A Study of Monozygotic Twin Pairs.

    PubMed

    Dubois, Lise; Diasparra, Maikol; Bogl, Leonie-Helen; Fontaine-Bisson, Bénédicte; Bédard, Brigitte; Tremblay, Richard E; Kaprio, Jaakko; Boivin, Michel

    2016-02-01

    There is a lack of evidence pointing to specific dietary elements related to weight gain and obesity prevention in childhood and adulthood. Dietary intake and obesity are both inherited and culturally transmitted, but most prospective studies on the association between diet and weight status do not take genetics into consideration. The objective of this study was to document the association between dietary intake at 9 years and subsequent Body Mass Index (BMI) in adolescent monozygotic boy and girl twin pairs. This research used data from 152 twin pairs. Dietary data were collected from two 24-hour-recall interviews with a parent and the child aged 9 years. Height and weight were obtained when the twins were aged 9, 12, 13, and 14 years. Intrapair variability analysis was performed to identify dietary elements related to BMI changes in subsequent years. BMI-discordant monozygotic twin pairs were also identified to analyze the dietary constituents that may have generated the discordance. After eliminating potential confounding genetic factors, pre-adolescent boys who ate fewer grain products and fruit and consumed more high-fat meat and milk had higher BMIs during adolescence; pre-adolescent girls who consumed more grain products and high-fat meat and milk had higher BMIs during adolescence. Energy intake (EI) at 9 years was not related to BMI in subsequent years. Our study suggests that messages and interventions directed at obesity prevention could take advantage of sex-specific designs and' eventually' genetic information. PMID:26810866

  12. Sex-discordant monochorionic twins with blood and tissue chimerism.

    PubMed

    Rodriguez-Buritica, David; Rojnueangnit, Kitiwan; Messiaen, Ludwine M; Mikhail, Fady M; Robin, Nathaniel H

    2015-04-01

    We report on a pair of normally conceived monochorionic/dizygotic (MC/DZ) sex discordant twins. The comparison of blood and skin genotypes revealed that the chimerism was also present in the skin. We conjecture about the developmental origins of this case.

  13. [Similarity of monozygotic twins regarding vocal performance and acoustic markers and possible clinical significance].

    PubMed

    Fuchs, M; Oeken, J; Hotopp, T; Täschner, R; Hentschel, B; Behrendt, W

    2000-06-01

    Auditory similarities in voices of monozygotic twins have already been described in the literature. However, is there a clinical relevance? Thus, the present study was designed to identify parameters of vocal performance and acoustic features which are significantly more similar in monozygotic twins than in non-related persons. In our hypothesis, comparable prerequisites for an increased vocal load in a profession or in an artistic education of the voice could be due to these similarities. We compared intra-pair differences with data from a control group. Moreover, we examined the correlation of intra-pair differences with the age of the monozygotic twins. A greater difference in older twin pairs than in younger pairs could show the effect of an exogene influence. In addition to the few phoniatric studies in twins in the literature, we used current methods for acoustic analysis. We examined seven parameters of vocal performance and three acoustic features in 31 monozygotic twin pairs (median age 36 years, range 18-75 years) and compared them with 30 control group pairs, which consisted of non-related persons of the same age and sex, newly combined from the group of monozygotic twins ("statistical twins"). We found significant differences in seven of ten parameters (vocal range, highest and lowest vocal fundamental frequency, fundamental speaking frequency, maximum voice intensity, number of partials, vibrato of intensity; U-test by Mann-Whitney). No correlation of the differences of the identical twins with age was found in the examined parameters. The voices of identical twins are significantly more similar than those of non-related persons regarding the above mentioned features. Thus, the suitability of the voices of monozygotic twins for professions with a high demand on voice is comparable. Results of the group comparison correlate largely with the literature. The missing correlation with age could be due to the fact that the environmental effects were not

  14. Exposure to organic solvents and neuropsychological dysfunction: a study on monozygotic twins.

    PubMed Central

    Hänninen, H; Antti-Poika, M; Juntunen, J; Koskenvuo, M

    1991-01-01

    Twenty one monozygotic twins exposed to organic solvents were compared with their non-exposed cotwins by performance in psychological tests. A further 28 monozygotic twin pairs were examined as a reference group. The study used 11 tests, 10 of which had shown an effect in previous studies on the results of exposure to solvents. Paired comparisons of the test scores showed the exposed twins to have lower performance in associative learning, digit span, and block design. These results agree with two previous studies that used a similar set of tests. Contrary to some other studies, psychomotor speed was not affected, but the results indicated a marginal effect on the control of hand movements. Further comparison of subgroups with a low and a high exposure showed the prevalence of subtle neuropsychological dysfunction to be greater among the more exposed twins. PMID:1993155

  15. Bidirectional influences between maternal parenting and children's peer problems: a longitudinal monozygotic twin difference study.

    PubMed

    Yamagata, Shinji; Takahashi, Yusuke; Ozaki, Koken; Fujisawa, Keiko K; Nonaka, Koichi; Ando, Juko

    2013-03-01

    This twin study examined the bidirectional relationship between maternal parenting behaviors and children's peer problems that were not confounded by genetic and family environmental factors. Mothers of 259 monozygotic twin pairs reported parenting behaviors and peer problems when twins were 42 and 48 months. Path analyses on monozygotic twin difference scores revealed that authoritative parenting (the presence of consistent discipline and lack of harsh parenting) and peer problems simultaneously influenced each other. Authoritative parenting reduced peer problems, and peer problems increased authoritative parenting. Neither consistent discipline nor harsh parenting alone was associated with peer problems. These results suggest that maternal authoritative parenting works protectively in regard to children's peer problems, and peer problems can evoke such effective parenting.

  16. Social Experiences in Kindergarten and Academic Achievement in Grade 1: A Monozygotic Twin Difference Study

    ERIC Educational Resources Information Center

    Vitaro, Frank; Boivin, Michel; Brendgen, Mara; Girard, Alain; Dionne, Ginette

    2012-01-01

    The goal of this study was to examine how different types of social experiences in kindergarten relate to Grade 1 academic achievement, while controlling for possible genetic and shared environmental influences through the use of the monozygotic (MZ) twin difference method. Social experiences in kindergarten included relationship quality with the…

  17. Concordance for neuroblastoma in monozygotic twins: case report and review of the literature.

    PubMed

    Tajiri, Tatsuro; Souzaki, Ryota; Kinoshita, Yoshiaki; Tanaka, Sakura; Koga, Yuhki; Suminoe, Aiko; Hara, Toshiro; Kohashi, Kenichi; Oda, Yoshinao; Masumoto, Kouji; Ohira, Miki; Nakagawara, Akira; Taguchi, Tomoaki

    2010-12-01

    The patients were infant male twins born by cesarean delivery following a healthy pregnancy at 36 weeks' gestation to unrelated parents. At 4 months of age, twin 2 presented with hepatomegaly and a right suprarenal mass. Resection of an adrenal tumor and a liver tumor biopsy were performed. Twin 1 had no symptoms at 4 months of age. Screening by abdominal ultrasonography showed multiple masses in the liver but no adrenal mass. Metaiodobenzylguanidine scintigraphy showed positive findings in multiple liver masses. A laparoscopic biopsy for a liver tumor was performed. All primary tumor and liver tumor specimens from twin 2 and the liver tumor of twin 1 had the same histologic classification of neuroblastoma and nearly identical genetic aberrations, including a chromosome gain or loss using array-comparative genomic hybridization. From these clinical and pathologic findings and genetic analyses, we strongly demonstrate the transplacental metastatic spread from twin 2 to twin 1. In the literature, 9 pairs of concordant twin neuroblastomas, including the current twin, have been presented; and the clinical findings of 5 twin pairs may represent placental metastases from one twin with congenital neuroblastoma to the other twin. This study is the first report presenting the possibility of twin-to-twin metastasis in monozygotic twins with neuroblastoma based on an analysis of the clinical features and genetic aberrations.

  18. Sex ratios provide evidence for monozygotic twinning in the ring-tailed lemur, Lemur catta.

    PubMed

    St Clair, John; Campbell-Palmer, Roisin; Lathe, Richard

    2014-02-01

    Monozygotic (MZ) twinning is generally considered to be rare in species other than human. We inspected sex ratios in European zoo-bred ring-tailed lemurs (Lemur catta), revealing a significant excess of same-sex twins. Of 94 pairs, 60 (64%) were either both males or both females (p = .004). Application of the Weinberg differential rule argues that 27% of all twins in this species are MZ pairs. In this protected species, where twinning is commonplace (~50% of newborns are twins), the probable existence of frequent MZ twinning has ramifications for breeding programs aimed to maximize genetic diversity, and suggests that twin studies in a species other than human could have potential as a medical research tool.

  19. Sex ratios provide evidence for monozygotic twinning in the ring-tailed lemur, Lemur catta.

    PubMed

    St Clair, John; Campbell-Palmer, Roisin; Lathe, Richard

    2014-02-01

    Monozygotic (MZ) twinning is generally considered to be rare in species other than human. We inspected sex ratios in European zoo-bred ring-tailed lemurs (Lemur catta), revealing a significant excess of same-sex twins. Of 94 pairs, 60 (64%) were either both males or both females (p = .004). Application of the Weinberg differential rule argues that 27% of all twins in this species are MZ pairs. In this protected species, where twinning is commonplace (~50% of newborns are twins), the probable existence of frequent MZ twinning has ramifications for breeding programs aimed to maximize genetic diversity, and suggests that twin studies in a species other than human could have potential as a medical research tool. PMID:24384029

  20. Increased physical activity decreases hepatic free fatty acid uptake: a study in human monozygotic twins

    PubMed Central

    Hannukainen, Jarna C; Nuutila, Pirjo; Ronald, Borra; Kaprio, Jaakko; Kujala, Urho M; Janatuinen, Tuula; Heinonen, Olli J; Kapanen, Jukka; Viljanen, Tapio; Haaparanta, Merja; Rönnemaa, Tapani; Parkkola, Riitta; Knuuti, Juhani; Kalliokoski, Kari K

    2007-01-01

    Exercise is considered to be beneficial for free fatty acid (FFA) metabolism, although reports of the effects of increased physical activity on FFA uptake and oxidation in different tissues in vivo in humans have been inconsistent. To investigate the heredity-independent effects of physical activity and fitness on FFA uptake in skeletal muscle, the myocardium, and liver we used positron emission tomography (PET) in nine healthy young male monozygotic twin pairs discordant for physical activity and fitness. The cotwins with higher physical activity constituting the more active group had a similar body mass index but less body fat and 18 ± 10% higher V˙O2,max (P < 0.001) compared to the less active brothers with lower physical activity. Low-intensity knee-extension exercise increased skeletal muscle FFA and oxygen uptake six to 10 times compared to resting values but no differences were observed between the groups at rest or during exercise. At rest the more active group had lower hepatic FFA uptake compared to the less active group (5.5 ± 4.3 versus 9.0 ± 6.1 μmol (100 ml)−1 min−1, P = 0.04). Hepatic FFA uptake associated significantly with body fat percentage (P = 0.05). Myocardial FFA uptake was similar between the groups. In conclusion, in the absence of the confounding effects of genetic factors, moderately increased physical activity and aerobic fitness decrease body adiposity even in normal-weighted healthy young adult men. Further, increased physical activity together with decreased intra-abdominal adiposity seems to decrease hepatic FFA uptake but has no effects on skeletal muscle or myocardial FFA uptake. PMID:17053033

  1. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder.

    PubMed

    Bootsman, F; Brouwer, R M; Schnack, H G; Kemner, S M; Hillegers, M H J; Sarkisyan, G; van der Schot, A C; Vonk, R; Hulshoff Pol, H E; Nolen, W A; Kahn, R S; van Haren, N E M

    2016-08-01

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume. A total of 50 twins from pairs discordant or concordant for BD (monozygotic: 8 discordant and 3 concordant pairs, and 1 patient and 3 co-twins from incomplete pairs; dizygotic: 6 discordant and 2 concordant pairs, and 1 patient and 7 co-twins from incomplete pairs) underwent magnetic resonance imaging twice. In addition, 57 twins from healthy twin pairs (15 monozygotic and 10 dizygotic pairs, and 4 monozygotic and 3 dizygotic subjects from incomplete pairs) were also scanned twice. Mean follow-up duration for all twins was 7.5 years (standard deviation: 1.5 years). Data were analyzed using structural equation modeling software OpenMx. The liability to BD was not associated with global or regional structural brain changes over time. Although we observed a subtle increase in cerebral white matter in BD patients, this effect disappeared after correction for multiple comparisons. Heritability of brain changes over time was generally low to moderate. Structural brain changes appear to follow similar trajectories in BD patients and healthy controls. Existing brain abnormalities in BD do not appear to progressively change over time, but this requires additional confirmation. Further study with large cohorts is recommended to assess genetic and environmental influences on structural brain abnormalities in BD, while taking into account the influence of lithium on the brain. PMID:27218817

  2. Fulminant Wilson's disease requiring liver transplantation in one monozygotic twin despite identical genetic mutation.

    PubMed

    Kegley, K M; Sellers, M A; Ferber, M J; Johnson, M W; Joelson, D W; Shrestha, R

    2010-05-01

    Acute decompensated Wilson's disease (WD) that presents as fulminant hepatic failure carries significant mortality without hepatic replacement. The abnormal gene implicated in WD, ATP7B, has been mapped to chromosome 13, and leads to decreased passage of copper from hepatocytes to bile. Excess copper accumulation exceeds hepatocyte storage capacity resulting in intracellular necrosis, apoptosis and cell death in various organs of the body. The hepatic injury induced by the abnormal accumulation of copper in WD has variable presentation such as acute hepatitis, rapid hepatic deterioration resembling fulminant hepatic failure, or as progressive chronic liver disease in the form of chronic active hepatitis or cirrhosis. There are reports in the literature describing monozygotic (identical) twins with similar hepatic progression requiring liver transplantation, however, with different neurological outcome after transplant. We report a case of one monozygotic twin presenting with acute liver failure requiring emergent liver transplantation while the other twin presented with mild liver disease, when both shared an identical genetic mutation.

  3. NOTE: Trends of discordant fetal growth in monochorionic twin pregnancies

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; Umur, Asli

    2000-08-01

    We derived simple analytical relations representing trends of discordant fetal growth in monochorionic twins developing the twin-twin transfusion syndrome from an approximation of previously developed model equations. In severe twin-twin transfusion syndrome cases, the difference between the estimated fetal weights of both twins increases proportional to (t-5)5 (t denotes gestational age in weeks) and the sum of both weights increases proportional to t3. Hence, the ratio between the difference of estimated fetal weights and the average of the two weights (difference average ratio) increases in proportion to (t-5)5/t3. In mild cases, the difference between estimated fetal weights as well as the sum of the two weights increases proportional to t3. Therefore, the difference average ratio becomes a constant. Comparison with clinical data of severe and mild cases showed surprisingly good agreement except after laser coagulation of placental anastomoses. These relations may therefore enable us to distinguish between severe and mild developing twin-twin transfusion syndrome cases.

  4. Functional neuroimaging study in identical twin pairs discordant for regular cigarette smoking.

    PubMed

    Lessov-Schlaggar, Christina N; Lepore, Rebecca L; Kristjansson, Sean D; Schlaggar, Bradley L; Barnes, Kelly Anne; Petersen, Steven E; Madden, Pamela A F; Heath, Andrew C; Barch, Deanna M

    2013-01-01

    Despite the tremendous public health and financial burden of cigarette smoking, relatively little is understood about brain mechanisms that subserve smoking behavior. This study investigated the effect of lifetime regular smoking on brain processing in a reward guessing task using functional magnetic resonance imaging and a co-twin control study design in monozygotic (MZ) twin pairs that maximally controls for genetic and family background factors. Young adult (24-34 years) MZ female twin pairs (n = 15 pairs), discordant for regular smoking defined using Centers for Disease Control criteria as having smoked ≥100 cigarettes in their lifetime, were recruited from an ongoing genetic epidemiological longitudinal study of substance use and psychopathology. We applied hypothesis-driven region of interest (ROI) and whole-brain analyses to investigate the effect of regular smoking on reward processing. Reduced response to reward and punishment in regular compared with never-regular smokers was seen in hypothesis-driven ROI analysis of bilateral ventral striatum. Whole-brain analysis identified bilateral reward-processing regions that showed activation differences in response to winning or losing money but no effect of regular smoking; and frontal/parietal regions, predominantly in the right hemisphere, that showed robust effect of regular smoking but no effect of winning or losing money. Altogether, using a study design that maximally controls for group differences, we found that regular smoking had modest effects on striatal reward processing regions but robust effects on cognitive control/attentional systems. PMID:22340136

  5. Gut microbiomes of Malawian twin pairs discordant for kwashiorkor.

    PubMed

    Smith, Michelle I; Yatsunenko, Tanya; Manary, Mark J; Trehan, Indi; Mkakosya, Rajhab; Cheng, Jiye; Kau, Andrew L; Rich, Stephen S; Concannon, Patrick; Mychaleckyj, Josyf C; Liu, Jie; Houpt, Eric; Li, Jia V; Holmes, Elaine; Nicholson, Jeremy; Knights, Dan; Ursell, Luke K; Knight, Rob; Gordon, Jeffrey I

    2013-02-01

    Kwashiorkor, an enigmatic form of severe acute malnutrition, is the consequence of inadequate nutrient intake plus additional environmental insults. To investigate the role of the gut microbiome, we studied 317 Malawian twin pairs during the first 3 years of life. During this time, half of the twin pairs remained well nourished, whereas 43% became discordant, and 7% manifested concordance for acute malnutrition. Both children in twin pairs discordant for kwashiorkor were treated with a peanut-based, ready-to-use therapeutic food (RUTF). Time-series metagenomic studies revealed that RUTF produced a transient maturation of metabolic functions in kwashiorkor gut microbiomes that regressed when administration of RUTF was stopped. Previously frozen fecal communities from several discordant pairs were each transplanted into gnotobiotic mice. The combination of Malawian diet and kwashiorkor microbiome produced marked weight loss in recipient mice, accompanied by perturbations in amino acid, carbohydrate, and intermediary metabolism that were only transiently ameliorated with RUTF. These findings implicate the gut microbiome as a causal factor in kwashiorkor.

  6. Gut microbiomes of Malawian twin pairs discordant for kwashiorkor

    PubMed Central

    Smith, Michelle I.; Yatsunenko, Tanya; Manary, Mark J.; Trehan, Indi; Mkakosya, Rajhab; Cheng, Jiye; Kau, Andrew L.; Rich, Stephen S.; Concannon, Patrick; Mychaleckyj, Josyf C.; Liu, Jie; Houpt, Eric; Li, Jia V.; Holmes, Elaine; Nicholson, Jeremy; Knights, Dan; Ursell, Luke K.; Knight, Rob; Gordon, Jeffrey I.

    2013-01-01

    Kwashiorkor, an enigmatic form of severe acute malnutrition, is the consequence of inadequate nutrient intake plus additional environmental insults. To investigate the role of the gut microbiome, we studied 317 Malawian twin pairs during the first 3 years of life. During this time, half of the twin pairs remained well-nourished, while 43% became discordant and 7% manifested concordance for acute malnutrition. Both children in twin pairs discordant for kwashiorkor were treated with a peanut-based, ready-to-use therapeutic food (RUTF). Time-series metagenomic studies revealed that RUTF produced a transient maturation of metabolic functions in kwashiorkor microbiomes that regressed when RUTF was stopped. Previously frozen fecal communities from several discordant pairs were each transplanted into gnotobiotic mice. The combination of Malawian diet and kwashiorkor microbiome produced marked weight loss in recipient mice, accompanied by perturbations in amino acid, carbohydrate and intermediary metabolism that were only transiently ameliorated with RUTF. These findings implicate the gut microbiome as a causal factor in kwashiorkor. PMID:23363771

  7. Neonatal morbidity in growth-discordant monochorionic twins: comparison between the larger and the smaller twin.

    PubMed

    Lopriore, Enrico; Sluimers, Carolien; Pasman, Suzanne A; Middeldorp, Johanna M; Oepkes, Dick; Walther, Frans J

    2012-08-01

    Fetal growth restriction in singletons has been shown to enhance fetal lung maturation and reduce the risk of respiratory distress syndrome due to increased endogenous steroid production. However, data on lung maturation in growth-discordant monochorionic (thus, identical) twins are lacking. Our objective was to compare the risk of severe neonatal morbidity between the larger and the smaller twin in monochorionic twins with birth weight discordance (BWD). We included in the study all consecutive monochorionic diamniotic pregnancies with severe BWD (≥25%) and two live-born twins delivered at our center (n=47 twin pairs). We compared the incidence of neonatal morbidity, particularly respiratory distress syndrome (RDS), and cerebral lesions between the larger and the smaller co-twin. The incidence of severe neonatal morbidity in the larger and smaller twin was 38% (18/47) and 19% (9/47), respectively (odds ratio (OR) 2.66, 95% confidence interval (CI) 0.94-7.44) and was due primarily to the higher incidence of RDS, 32% (15/47) and 6% (3/47), respectively (OR 6.88, 95% CI 1.66-32.83). In conclusion, this study shows that the larger twin in monochorionic twin pairs with BWD is at increased risk of severe neonatal morbidity, particularly RDS, compared to the smaller twin. PMID:22854118

  8. Comparisons of dermatoglyphic patterns in monochorionic and dichorionic monozygotic twins.

    PubMed Central

    Reed, T; Uchida, I A; Norton, J A; Christian, J C

    1978-01-01

    The data presented here indicate that different influences affect dermatoglyphic pattern development in MC-MZ and DC-MZ twins. Only five of 84 variables had significant mean differences but their clustering suggested a real difference in mean placement of the atd angle. Nineteen of 84 variables had significantly different within-pair mean squares for the two twin types. Larger numbers of twins will be required to obtain accurate estimates of the magnitude of the dermatoglyphic differences between MC-MZ and DC-MZ twins. Studies of dermatoglyphics in MC-MZ and DC-MZ twins are important to the understanding of factors which influence early embryonic development and when better documented may provide a mechanism for retrospectively diagnosing placental type of MZ twins. PMID:568879

  9. Maternal serum alpha fetoprotein in monozygotic and dizygotic twin pregnancies.

    PubMed

    Thom, H; Buckland, C M; Campbell, A G; Thompson, B; Farr, V

    1984-01-01

    Maternal serum alpha-fetoprotein (MSAFP) values in the second trimester have been related to pregnancy outcome for 100 normal twin pairs, 42 monozygous (MZ) and 58 dizygous (DZ), liveborn after 28 weeks gestation. The median MSAFP value was 1.9 multiples of the median value (MOM) for uncomplicated singleton pregnancies. Both very low and very high MSAFP values were associated with twins of low birthweight. MSAFP values were higher in MZ than DZ twin pregnancies particularly those with dizygotes of like-sex. This effect was even more marked when only dichorionic like-sex twin pairs were compared. PMID:6209699

  10. Vocal fold bowing in elderly male monozygotic twins: a case study.

    PubMed

    Tanner, Kristine; Sauder, Cara; Thibeault, Susan L; Dromey, Christopher; Smith, Marshall E

    2010-07-01

    This case study examined case histories, diagnostic features, and treatment response in two 79-year-old male monozygotic (identical) twins with vocal fold bowing, exploring both genetic and environmental factors. DNA concordance was examined via cheek swab. Case histories, videostroboscopy, auditory- and visual-perceptual assessment, electromyography, acoustic measures, and Voice Handicap ratings were undertaken. Both twins underwent surgical intervention and subsequent voice therapy. Monozygosity was confirmed for DNA polymorphisms, with 10 of 10 concordance for STR DNA markers. For both twins, auditory- and visual-perceptual assessments indicated severe bowing, hoarseness, and breathiness, although Twin 1 was judged to be extremely severe. Differences in reference to root-mean-square amplitudes were observed for thyroarytenoid and lateral cricoarytenoid muscles, with smaller relative amplitudes observed for the Twin 1 versus Twin 2. No consistent voice improvement was observed after surgical intervention(s), despite improved mid-membranous vocal fold closure. Marked reductions in Voice Handicap Index total scores were observed after behavioral voice therapy, coinciding with increased mid-membranous and posterior laryngeal (interarytenoid) glottal closure. No substantive differences in acoustic measures were observed. Vocal fold bowing was more severe for Twin 1 versus Twin 2 despite identical heritability factors. Overall voice improvement with treatment was greater for Twin 2 than Twin 1. Environmental factors might partially account for the differences observed between the twins, including variability in their responsiveness to behavioral voice therapy. Voice therapy was useful in improving mid-membranous and posterior laryngeal closure, although dysphonia remained severe in both cases.

  11. 45,X Turner's syndrome in monozygotic twin sisters.

    PubMed Central

    Pescia, G; Ferrier, P E; Wyss-Hutin, D; Klein, D

    1975-01-01

    A 7-year-old girl was admitted to the hospital for anaemia, secondary to intestinal blood los (melaena). She was found to have 45,X Turner's syndrome. Her identical twin sister also had Turner's syndrome with a 45,X chromosome complement. According to various criteria the probability of monozygosity was 0.9905. Although the incidence of twinning is greater than usual in families of patients with Turner's syndrome, affected cases have only been observed in twin sisters on six occasions. It seems therefore that the 45,X chromosome complement itself is not a factor predisposing to twinning, but that in some families, a factor is at play, which cuases either twinning or the 45,X aneuploidy, or both. Images PMID:1240972

  12. Suicidal Behaviors in Surviving Monozygotic and Dizygotic Co-Twins: Is the Nature of the Co-Twin's Cause of Death a Factor?

    ERIC Educational Resources Information Center

    Segal, Nancy L.

    2009-01-01

    Genetically informative samples can address hereditary and experiential influences on suicide-related behaviors. The frequency of suicide-related behaviors was compared in twins from two survivor groups: (1) those whose co-twins' deaths were suicides (monozygotic [MZ]: n = 47; dizygotic [DZ]: n = 31), and (2) those whose co-twins' deaths were…

  13. Use of alternative treatments by chronic fatigue syndrome discordant twins.

    PubMed

    Afari; Eisenberg; Herrell; Goldberg; Kleyman; Ashton; Buchwald

    2000-03-21

    Background: Patients with chronic fatigue syndrome (CFS) have been faced with difficulties in diagnosis and lack of effective treatments. Anecdotal evidence suggests that use of alternative treatments may be common in these patients. Our primary objective was to compare the prevalence and patterns of alternative medicine use among twins who met the Centers for Disease Control and Prevention (CDC) CFS criteria to that of their non-CFS co-twins. Secondary goals were to assess how often alternative medicine use was discussed with physicians and the perceived benefit of these therapies. Methods: Sixty-three twin pairs discordant for CFS completed a survey about their use of 22 alternative therapies. Matched pair odds ratios and 95% confidence intervals were used to examine differences in the use between CFS twins and their non-CFS co-twins. Results: 91% of twins with CFS and 71% of non-CFS twins had used at least 1 alternative treatment in their lifetime. Twins with CFS were more likely to use homeopathy, mega-vitamins, herbal therapies, biofeedback, relaxation/meditation, guided imagery, massage therapy, energy healing, religious healing by others, and self-help groups than their non-CFS counterparts. A large proportion of all twins found alternative therapies helpful; however, only 42% of those with CFS and 23% of those without CFS discussed their use of alternative medicine with a physician. Conclusions: Individuals with CFS frequently used alternative medical treatments yet rarely communicated this use to their medical doctor. Future research should ascertain the usefulness of alternative practices in the management of CFS.

  14. Monozygotic twins with Marfan's syndrome and ascending aortic aneurysm.

    PubMed

    Redruello, Héctor Jorge; Cianciulli, Tomas Francisco; Rostello, Eduardo Fernandez; Recalde, Barbara; Lax, Jorge Alberto; Picone, Victorio Próspero; Belforte, Sandro Mario; Prezioso, Horacio Alberto

    2007-08-01

    Marfan's syndrome is a hereditary connective tissue disease, in which cardiovascular abnormalities (especially aortic root dilatation) are the most important cause of morbidity and mortality. In this report, we describe two 24-year-old twins, with a history of surgery for lens subluxation and severe cardiovascular manifestations secondary to Marfan's syndrome. One of the twins suffered a type A aortic dissection, which required replacement of the ascending aorta, and the other twin had an aneurysmal dilatation of the ascending aorta (46mm) and was prescribed medical treatment with atenolol and periodic controls to detect the presence of a critical diameter (50mm) that would indicate the need for prophylactic surgery.

  15. The timing of monozygotic twinning: a pro-life challenge to conventional scientific wisdom.

    PubMed

    Gardner, R L

    2014-03-01

    A recent paper in Zygote criticizes the 'theory of origins' of the various classes of monozygotic twins originally proposed and developed by Corner. It does so on the basis of recent observations on human IVF embryos. Here, the validity of one of the evidential sources is upheld, but an alternative explanation is proposed that is more plausibly based on evidence than the explanation offered in Zygote.

  16. Brain Activation during Memory Encoding in Type 2 Diabetes Mellitus: A Discordant Twin Pair Study.

    PubMed

    Wood, Amanda G; Chen, Jian; Moran, Christopher; Phan, Thanh; Beare, Richard; Cooper, Kimberley; Litras, Stacey; Srikanth, Velandai

    2016-01-01

    Type 2 diabetes mellitus increases the risk of dementia and neuronal dysfunction may occur years before perceptible cognitive decline. We aimed to study the impact of type 2 diabetes on brain activation during memory encoding in middle-aged people, controlling for age, sex, genes, and early-shared environment. Twenty-two twin pairs discordant for type 2 diabetes mellitus (mean age 60.9 years) without neurological disease were recruited from the Australian Twin Registry (ATR) and underwent functional magnetic resonance imaging (fMRI) during a memory encoding task, cognitive tests, and structural MRI. Type 2 diabetes was associated with significantly reduced activation in left hemisphere temporoparietal regions including angular gyrus, supramarginal gyrus, and middle temporal gyrus and significantly increased activation in bilateral posteriorly distributed regions. These findings were present in the absence of within-pair differences in standard cognitive test scores, brain volumes, or vascular lesion load. Differences in activation were more pronounced among monozygotic (MZ) pairs, with MZ individuals with diabetes also displaying greater frontal activation. These results provide evidence for preclinical memory-related neuronal dysfunction in type 2 diabetes. They support the search for modifiable later-life environmental factors or epigenetic mechanisms linking type 2 diabetes and cognitive decline. PMID:27314047

  17. Functional Neuroimaging Study in Identical Twin Pairs Discordant for Regular Cigarette Smoking

    PubMed Central

    Lessov-Schlaggar, Christina N.; Lepore, Rebecca L.; Kristjansson, Sean D.; Schlaggar, Bradley L.; Barnes, Kelly Anne; Petersen, Steven E.; Madden, Pamela A. F.; Heath, Andrew C.; Barch, Deanna M.

    2012-01-01

    Despite the tremendous public health and financial burden of cigarette smoking, relatively little is understood about brain mechanisms that subserve smoking behavior. This study investigated the effect of lifetime regular smoking on brain processing in a reward guessing task using functional magnetic resonance imaging (fMRI) and a cotwin-control study design in monozygotic (MZ) twin pairs that maximally controls for genetic and family background factors. Young adult (24–34 years) MZ female twin pairs (n=15 pairs), discordant for regular smoking defined using Centers for Disease Control (CDC) criteria as having smoked ≥100 cigarettes lifetime were recruited from an ongoing genetic epidemiological longitudinal study of substance use and psychopathology. We applied hypothesis-driven region of interest and whole brain analyses to investigate the effect of regular smoking on reward processing. Reduced response to reward and punishment in regular compared to never-regular smokers was seen in hypothesis-driven region of interest analysis of bilateral ventral striatum. Whole brain analysis identified bilateral reward-processing regions that showed activation differences in response to winning or losing money but no effect of regular smoking; and frontal/parietal regions, predominantly in the right hemisphere, that showed robust effect of regular smoking but no effect of winning or losing money. Altogether, using a study design that maximally controls for group differences, we found that regular smoking had modest effects on striatal reward processing regions but robust effects on cognitive control/attentional systems. PMID:22340136

  18. Brain Activation during Memory Encoding in Type 2 Diabetes Mellitus: A Discordant Twin Pair Study

    PubMed Central

    Wood, Amanda G.; Chen, Jian; Moran, Christopher; Phan, Thanh; Beare, Richard; Cooper, Kimberley; Litras, Stacey; Srikanth, Velandai

    2016-01-01

    Type 2 diabetes mellitus increases the risk of dementia and neuronal dysfunction may occur years before perceptible cognitive decline. We aimed to study the impact of type 2 diabetes on brain activation during memory encoding in middle-aged people, controlling for age, sex, genes, and early-shared environment. Twenty-two twin pairs discordant for type 2 diabetes mellitus (mean age 60.9 years) without neurological disease were recruited from the Australian Twin Registry (ATR) and underwent functional magnetic resonance imaging (fMRI) during a memory encoding task, cognitive tests, and structural MRI. Type 2 diabetes was associated with significantly reduced activation in left hemisphere temporoparietal regions including angular gyrus, supramarginal gyrus, and middle temporal gyrus and significantly increased activation in bilateral posteriorly distributed regions. These findings were present in the absence of within-pair differences in standard cognitive test scores, brain volumes, or vascular lesion load. Differences in activation were more pronounced among monozygotic (MZ) pairs, with MZ individuals with diabetes also displaying greater frontal activation. These results provide evidence for preclinical memory-related neuronal dysfunction in type 2 diabetes. They support the search for modifiable later-life environmental factors or epigenetic mechanisms linking type 2 diabetes and cognitive decline. PMID:27314047

  19. Danish cohort of monozygotic inflammatory bowel disease twins: Clinical characteristics and inflammatory activity

    PubMed Central

    Moller, Frederik Trier; Knudsen, Lina; Harbord, Marcus; Satsangi, Jack; Gordon, Hannah; Christiansen, Lene; Christensen, Kaare; Jess, Tine; Andersen, Vibeke

    2016-01-01

    AIM: To describe the establishment of a Danish inflammatory bowel diseases (IBD) twin cohort with focus on concordance of treatment and inflammatory markers. METHODS: We identified MZ twins, likely to be discordant or concordant for IBD, by merging information from the Danish Twin Register and the National Patient Register. The twins were asked to provide biological samples, questionnaires, and data access to patient files and public registries. Biological samples were collected via a mobile laboratory, which allowed for immediate centrifugation, fractionation, and storage of samples. The mean time from collection of samples to storage in the -80 °C mobile freezer was less than one hour. The diagnoses where validated using the Copenhagen diagnostic criteria. RESULTS: We identified 159 MZ IBD twin pairs, in a total of 62 (39%) pairs both twins agreed to participate. Of the supposed 62 IBD pairs, the IBD diagnosis could be confirmed in 54 pairs. The cohort included 10 concordant pairs, whereof some were discordant for either treatment or surgery. The 10 concordant pairs, where both pairs suffered from IBD, included eight CD/CD pairs, one UC/UC pair and one UC/IBDU pair. The discordant pairs comprised 31 UC, 5 IBDU (IBD unclassified), and 8 CD discordant pairs. In the co-twins not affected by IBD, calprotectin was above 100 μg/g in 2 participants, and above 50 μg/g in a further 5 participants. CONCLUSION: The presented IBD twin cohorts are an excellent resource for bioinformatics studies with proper adjustment for disease-associated exposures including medication and inflammatory activity in the co-twins. PMID:27275097

  20. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    PubMed

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel.

  1. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    PubMed

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel. PMID:27121223

  2. The Impact of the in utero and Early Postnatal Environments on Grey and White Matter Volume: A Study with Adolescent Monozygotic Twins.

    PubMed

    Levesque, Melissa L; Fahim, Cherine; Ismaylova, Elmira; Verner, Marie-Pier; Casey, Kevin F; Vitaro, Frank; Brendgen, Mara; Dionne, Ginette; Boivin, Michel; Tremblay, Richard E; Booij, Linda

    2015-01-01

    Prenatal and early postnatal adversities have been shown to be associated with brain development. However, we do not know how much of this association is confounded by genetics, nor whether the postnatal environment can moderate the impact of in utero adversity. This study used a monozygotic (MZ) twin design to assess (1) the association between birth weight (BW) and brain volume in adolescence, (2) the association between within-twin-pair BW discordance and brain volume discordance in adolescence, and (3) whether the association between BW and brain volume in adolescence is mediated or moderated by early negative maternal parenting behaviours. These associations were assessed in a sample of 108 MZ twins followed longitudinally since birth and scanned at age 15. The total grey matter (GM) and white matter (WM) volumes were obtained using the Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL) toolbox in the Statistical Parametric Mapping version 8 (SPM8). We found that the BW was significantly associated with the total GM and WM volumes, particularly in the superior frontal gyrus and thalamus. Within-twin-pair discordance in BW was also significantly associated with within-pair discordance in both the GM and the WM volumes, supporting the hypothesis that the specific in utero environment is associated with brain development independently of genetics. Early maternal hostile parenting behaviours and depressive symptoms were associated with total GM volume but not WM volume. Finally, greater early maternal hostility may moderate the association between the BW and GM volume in adolescence, since the positive association between the BW and total GM volume appeared stronger at higher levels of maternal hostility (trend). Together, these findings support the importance of the in utero and early environments for brain development.

  3. [Concordant deuteranomaly in monozygotic twin sisters (author's transl)].

    PubMed

    Franceschetti, A T; Klein, D; Dieterle, P

    1976-12-01

    Colorblind twin sisters were born from the marriage of a hemizygote with a carrier for colorblindness. The proof of monozygosity is given by the blood-group typing and the dermatoglyphs. The deuteranomaly is of the same degree in each but is more marked in one of the sisters. The mother has none of the microsymptoms sometimes found in carriers. PMID:1088162

  4. Differentiating between monozygotic twins through next-generation mitochondrial genome sequencing.

    PubMed

    Wang, Zheng; Zhu, Ruxin; Zhang, Suhua; Bian, Yinnan; Lu, Daru; Li, Chengtao

    2015-12-01

    Monozygotic (MZ) twins, considered to be genetically identical, cannot be distinguished from one another by standard forensic DNA testing. A recent study employed whole genome sequencing to identify extremely rare mutations and reported that mutation analysis could be used to differentiate between MZ twins. Compared with nuclear DNA, mitochondrial DNA (mtDNA) has higher mutation rates; therefore, minor differences theoretically exist in MZ twins' mitochondrial genome (mtGenome). However, conventional Sanger-type sequencing (STS) is neither amenable to, nor feasible for, the detection of low-level sequence variants. The recent introduction of massively parallel sequencing (MPS) has the capability to sequence many targeted regions of multiple samples simultaneously with desirable depth of coverage. Thus, the aim of this study was to assess whether full mtGenome sequencing analysis can be used to differentiate between MZ twins. Ten sets of MZ twins provided blood samples that underwent extraction, quantification, mtDNA enrichment, library preparation, and ultra-deep sequencing. Point heteroplasmies were observed in eight sets of MZ twins, and a single nucleotide variant (nt15301) was detected in five sets of MZ twins. Thus, this study demonstrates that ultra-deep mtGenome sequencing could be used to differentiate between MZ twins. PMID:26327617

  5. The Discordant MZ-Twin Method: One Step Closer to the Holy Grail of Causality

    ERIC Educational Resources Information Center

    Vitaro, Frank; Brendgen, Mara; Arseneault, Louise

    2009-01-01

    Twin studies are well known for their value in quantifying the contribution of genes to population variation in behaviors and personality traits. Twin studies also provide a unique opportunity to untangle the contribution of environmental experiences to emotional and behavioral development. This is particularly true when examining monozygotic (MZ)…

  6. Vocal Fold Bowing in Elderly Male Monozygotic Twins: A Case Study

    PubMed Central

    Tanner, Kristine; Sauder, Cara; Thibeault, Susan L.; Dromey, Christopher; Smith, Marshall E.

    2009-01-01

    Objectives This study examined case histories, diagnostic features, and treatment response in two 79-year-old male monozygotic (identical) twins with vocal fold bowing, exploring both genetic and environmental factors. Study Design Case study. Methods DNA concordance was examined via cheek swab. Case histories, videostroboscopy, auditory- and visual-perceptual assessment, electromyography, acoustic measures, and Voice Handicap ratings were undertaken. Both twins underwent surgical intervention and subsequent voice therapy. Results Monozygosity was confirmed for DNA polymorphisms, with 10 of 10 concordance for STR DNA markers. For both twins, auditory and visual-perceptual assessments indicated severe bowing, hoarseness and breathiness, although Twin 1 was judged to be extremely severe. Differences in RMS amplitudes were observed for TA and LCA muscles, with smaller relative amplitudes observed for the Twin 1 versus Twin 2. No consistent voice improvement was observed following surgical intervention(s), despite improved mid-membranous vocal fold closure. Marked reductions in Voice Handicap Index total scores were observed following behavioral voice therapy, coinciding with increased mid-membranous and posterior laryngeal (interarytenoid) glottal closure. No substantive differences in acoustic measures were observed. Conclusions Vocal fold bowing was more severe for Twin 1 versus Twin 2 despite identical heritability factors. Overall voice improvement with treatment was greater for Twin 2 than Twin 1. Environmental factors might partially account for the differences observed between the twins, including variability in their responsiveness to behavioral voice therapy. Voice therapy was useful in improving mid-membranous and posterior laryngeal closure, although dysphonia remained severe in both cases. PMID:19664899

  7. Impact of hip fracture on mortality: a cohort study in hip fracture discordant identical twins.

    PubMed

    Michaëlsson, Karl; Nordström, Peter; Nordström, Anna; Garmo, Hans; Byberg, Liisa; Pedersen, Nancy L; Melhus, Håkan

    2014-02-01

    Several studies have shown a long-lasting higher mortality after hip fracture, but the reasons for the excess risk are not well understood. We aimed to determine whether a higher mortality after hip fracture exists when controlling for genetic constitution, shared environment, comorbidity, and lifestyle by use of a nationwide cohort study in hip fracture discordant monozygotic twins. All 286 identical Swedish twin pairs discordant for hip fracture (1972 to 2010) were identified. Comorbidity and lifestyle information was retrieved by registers and questionnaire information. We used intrapair Cox regression to compute multivariable-adjusted hazard ratios (HRs) for death. During follow-up, 143 twins with a hip fracture died (50%) compared with 101 twins (35%) without a hip fracture. Through the first year after hip fracture, the rate of death increased fourfold in women (HR = 3.71; 95% confidence interval [CI] 1.32-10.40) and sevenfold in men (HR = 6.67; 95% CI 1.47-30.13). The increased rate in women only persisted during the first year after hip fracture (HR after 1 year = 0.99; 95% CI 0.66-1.50), whereas the corresponding HR in men was 2.58 (95% CI 1.02-6.62). The higher risk in men after the hip fracture event was successively attenuated during follow-up. After 5 years, the hazard ratio in men with a hip fracture was 1.19 (95% CI 0.29-4.90). On average, the hip fracture contributed to 0.9 years of life lost in women (95% CI 0.06-1.7) and 2.7 years in men (95% CI 1.7-3.7). The potential years of life lost associated with the hip fracture was especially pronounced in older men (>75 years), with an average loss of 47% (95% CI 31-61) of the expected remaining lifetime. We conclude that both women and men display a higher mortality after hip fracture independent of genes, comorbidity, and lifestyle. PMID:23821464

  8. Double jeopardy: multi-modality imaging of monozygotic "twin cap" atherosclerosis.

    PubMed

    Murray, Scott W; Cooper, Robert M; Appleby, Clare; McCann, Caroline; Binukrishnan, Sukumaran; Radu, Maria D; Stables, Rodney H

    2014-11-01

    The investigation of asymptomatic but potentially vulnerable atherosclerosis is not yet a major focus for clinical Cardiologists. We have illustrated the contemporary investigation and treatment of such disease using a clinical case that involved monozygotic twins. One twin (T1) had unfortunately suffered a cardiac arrest whilst jogging and survived only due to bystander CPR and prompt defibrillation. His identical twin brother (T2), on subsequent investigation, harbours a compositionally identical lesion in a proximal coronary vessel that has not yet ruptured or provoked a clinical event. Following the presentation of both non-invasive and invasive images, we discuss the need for active suspicion and intensive treatment for those people with a 'genetic' risk of future myocardial infarction.

  9. Double jeopardy: multi-modality imaging of monozygotic "twin cap" atherosclerosis.

    PubMed

    Murray, Scott W; Cooper, Robert M; Appleby, Clare; McCann, Caroline; Binukrishnan, Sukumaran; Radu, Maria D; Stables, Rodney H

    2014-11-01

    The investigation of asymptomatic but potentially vulnerable atherosclerosis is not yet a major focus for clinical Cardiologists. We have illustrated the contemporary investigation and treatment of such disease using a clinical case that involved monozygotic twins. One twin (T1) had unfortunately suffered a cardiac arrest whilst jogging and survived only due to bystander CPR and prompt defibrillation. His identical twin brother (T2), on subsequent investigation, harbours a compositionally identical lesion in a proximal coronary vessel that has not yet ruptured or provoked a clinical event. Following the presentation of both non-invasive and invasive images, we discuss the need for active suspicion and intensive treatment for those people with a 'genetic' risk of future myocardial infarction. PMID:25282686

  10. Nonshared environmental effects on adulthood psychopathic personality traits: results from a monozygotic twin difference scores analysis.

    PubMed

    Beaver, Kevin M; Vaughn, Michael G; Delisi, Matt

    2013-09-01

    An emerging body of empirical research has revealed that nonshared environmental factors are associated with explaining variance in measures of psychopathy and psychopathic personality traits. The current study adds to this existing knowledge base by analyzing a measure of psychopathy derived, in part, from the five factor model in a sample of monozygotic (MZ) twin pairs drawn from the National Longitudinal Study of Adolescent Health. The results of the MZ twin difference scores analysis revealed that nonshared environmental factors found within the family were unrelated to between-twin differences in psychopathic personality traits. Only one nonshared factor--levels of self-control--consistently predicted psychopathy. We conclude by discussing the implications of our findings and the limitations of our study.

  11. Non-syndromic multiple hyperdontia in monozygotic twin sisters: a report of two cases.

    PubMed

    Ratson, Tal; Peretz, Benjamin

    2014-01-01

    Supernumerary teeth are common in the general population, with a prevalence that varies between 0.1 percent to 3.8 percent. Multiple supernumerary teeth are associated with Gardner's syndrome, Fabry-Anderson syndrome, Ehlers-Danlos syndrome, labial palatal cleft, and cleidocranial dysplasia. Multiple hyperdontia not associated with syndromes is rare and ranges between 0.04 percent to 0.1 percent. The purpose of this report was to describe the occurrence of nonsyndromic multiple hyperdontia in monozygotic twin sisters. PMID:24709435

  12. A spare or an individual? Cloning and the implications of monozygotic twinning.

    PubMed

    Bryan, E M

    1998-01-01

    The creation of Dolly, the cloned sheep, raises the scenario of cloning in humans. Neither the case for, nor against, the ethics of cloning in humans is discussed in this paper. Instead, it considers the neglected issue of the likely happiness or otherwise of the resulting children if they are born as monozygotic twins or triplets. The advantages and disadvantages of twinship are discussed in detail, and it is concluded that recognized medical risks, and incompletely understood psychological effects, should be given serious consideration.

  13. Bullous emphysema as first presentation of Ehlers-Danlos syndrome in monozygotic twins.

    PubMed

    Ruggeri, Paolo; Calcaterra, Salvatore; Girbino, Giuseppe

    2015-01-01

    Ehlers-Danlos syndrome, characterized by hyperextensible skin, hypermobile joints, and fragile vessels, is the most common heritable disorder of connective tissue and has an estimated prevalence of 1 in 5000. Pulmonary involvement with signs of lung destruction (bullous emphysema) as first presentation is unusual. We report a case of monozygotic twins 37 years old men with occasional evidence of bullous emphysema with previously undiagnosed Ehlers-Danlos syndrome type IV. We emphasize the importance of considering uncommon genetic causes of emphysema in young adults, discuss underlining pathophysiological mechanisms and propose a conservative management and follow-up. PMID:26029576

  14. Optic glioma with progressive occlusion of the aqueduct of Sylvius in monozygotic twins with neurofibromatosis.

    PubMed

    Pascual-Castroviejo, I; Verdú, A; Román, M; De la Cruz-Medina, M; Villarejo, F

    1988-01-01

    Monozygotic twins sisters with optic glioma "in mirror image" (one with involvement of the left optic nerve and the other with the right optic nerve) and hydrocephalus secondary to progressive stenosis of the aqueduct have been found in a series of 128 cases below 14 years of age with neurofibromatosis. The optic glioma was diagnosed in each of the twins at 2 years of age. In one twin the tumor involved only the optic nerve but in the other the glioma affected the optic nerve and spread to the homolateral zone of the optic chiasm. First symptoms of hydrocephalus appeared at 8 years and 11 years of age respectively but ventriculo-peritoneal shunting procedures were performed to relieve intracranial hypertension at 11 years and 15 years of age respectively. At 2 years of age both twins had pneumoencephalography which demonstrated normal air passage through the aqueduct and cerebral ventricles of normal size and morphology. Posterior studies with CT-scan demonstrated progressive obstruction of the aqueduct with very slow progression of the hydrocephalus in each twin, although it was not observed simultaneously. The increased intracranial pressure was tolerated for many years in each twin without obvious symptoms which could be attributed to the slow progression of the aqueduct obstruction.

  15. Habitual dietary intake is associated with stool microbiota composition in monozygotic twins.

    PubMed

    Simões, Catarina D; Maukonen, Johanna; Kaprio, Jaakko; Rissanen, Aila; Pietiläinen, Kirsi H; Saarela, Maria

    2013-04-01

    The impact of diet on the gut microbiota has usually been assessed by subjecting people to the same controlled diet and thereafter following the shifts in the microbiota. In the present study, we used habitual dietary intake, clinical data, quantitative polymerase chain reaction, and denaturing gradient gel electrophoresis (DGGE) to characterize the stool microbiota of Finnish monozygotic twins. The effect of diet on the numbers of bacteria was described through a hierarchical linear mixed model that included the twin individuals, stratified by body mass index, and their families as random effects. The abundance and diversity of the bacterial groups studied did not differ between normal-weight, overweight, and obese individuals with the techniques used. Intakes of energy, monounsaturated fatty acids, n3 polyunsaturated fatty acids (PUFAs), n6 PUFAs, and soluble fiber had significant associations with the stool bacterial numbers (e.g., increased energy intake was associated with reduced numbers of Bacteroides spp.). In addition, co-twins with identical energy intake had more similar numbers and DGGE-profile diversities of Bacteroides spp. than did the co-twins with different intake. Moreover, the co-twins who ingested the same amounts of saturated fatty acids had very similar DGGE profiles of Bacteroides spp., whereas the co-twins with similar consumption of fiber had a very low bifidobacterial DGGE-profile similarity. In conclusion, our findings confirm that the diet plays an important role in the modulation of the stool microbiota, in particular Bacteroides spp. and bifidobacteria. PMID:23343669

  16. A monozygotic twin differences study of nonshared environmental influence on adolescent depressive symptoms.

    PubMed

    Liang, Holan; Eley, Thalia C

    2005-01-01

    The monozygotic (MZ) twin differences method was used to examine nonshared environmental aspects of the association of parenting (punitive and constructive discipline), negative life events (independent and dependent), and peers (antisocial and prosocial) with adolescent depressive symptoms in terms of sequelae, risk, and maintaining factors. Two self-report booklets were completed by 328 MZ twin pairs aged 12-19 years, 6 months apart. Increased punitive discipline and negative life events were found to be relevant nonshared environmental factors that followed depression. Negative life events were the only factor that had a direct nonshared environmental association with concurrent depressive symptoms in adolescents independent of previous depressive symptoms, and all other study variables. PMID:16274438

  17. MSX1 and PAX9 investigation in monozygotic twins with variable expression of tooth agenesis.

    PubMed

    Lopez, Sofia I N; Mundstock, Karina S; Paixão-Côrtes, Vanessa R; Schüler-Faccini, Lavínia; Mundstock, Carlos A; Bortolini, Maria Cátira; Salzano, Francisco M

    2013-12-01

    Non-syndromic agenesis of permanent teeth is one of the most common anomalies in human development, a multifactorial characteristic caused by genetic and environmental factors. We describe a pair of monozygotic twins who showed second premolar and third molar agenesis, albeit with different expressions. We studied the DNA of two genes, paired domain box gene 9 (PAX9) and muscle segment homeodomain-homeobox1 (MSX1), encoding transcription factors that earlier studies found were involved in the manifestation of this condition. No specific causative mutation was found. However, we detected a C→T change in MSX1 exon 2 in both twins, suggesting that this polymorphism might be involved in the trait's expression. PMID:24103583

  18. The timing of monozygotic twinning: a criticism of the common model.

    PubMed

    Herranz, Gonzalo

    2015-02-01

    In the dominant model, monozygotic (MZ) twinning is universally accepted as a post-fertilization event resulting from splitting of the embryo along its first 2 weeks of development. The stage at which splitting occurs determines chorionicity and amnionicity. A short history on how the model was built is presented, stressing the role played by some embryologists, in particular George Corner, in its completion and final success. Strikingly, for more than 60 years no deep criticisms have been raised against the model, which, in virtue of its rational and plausible character, enjoys the status of undisputed truth. At close examination, the embryological support of the model shows some important weak points, particularly when dealing with late splitting. In the author's view, the model not only has contributed to 'suspend' our knowledge on the timing of MZ twinning, but seems indefensible and claims to be substituted. That factor could imply relevant consequences for embryology and bioethics. As an alternative to the model, a new theory to explain the timing of MZ twinning is proposed. It is based on two premises. First, MZ twinning would be a fertilization event. In that case, due to an alteration of the zygote-blastomere transition, the first zygotic division, instead of producing two blastomeres, generates twin zygotes. Second, monochorionicity and monoamnionicity would not depend on embryo splitting, but on fusion of membranes. Some support for this theory can be found in recent embryological advances and also in some explanations of old.

  19. Impact of Early Environment on Children's Mental Health: Lessons From DNA Methylation Studies With Monozygotic Twins.

    PubMed

    Chiarella, Julian; Tremblay, Richard E; Szyf, Moshe; Provençal, Nadine; Booij, Linda

    2015-12-01

    Over the past decade, epigenetic analyses have made important contributions to our understanding of healthy development and a wide variety of adverse conditions such as cancer and psychopathology. There is increasing evidence that DNA methylation is a mechanism by which environmental factors influence gene transcription and, ultimately, phenotype. However, differentiating the effects of the environment from those of genetics on DNA methylation profiles remains a significant challenge. Monozygotic (MZ) twin study designs are unique in their ability to control for genetic differences because each pair of MZ twins shares essentially the same genetic sequence with the exception of a small number of de novo mutations and copy number variations. Thus, differences within twin pairs in gene expression and phenotype, including behavior, can be attributed in the majority of cases to environmental effects rather than genetic influence. In this article, we review the literature showing how MZ twin designs can be used to study basic epigenetic principles, contributing to understanding the role of early in utero and postnatal environmental factors on the development of psychopathology. We also highlight the importance of initiating longitudinal and experimental studies with MZ twins during pregnancy. This approach is especially important to identify: (1) critical time periods during which the early environment can impact brain and mental health development, and (2) the specific mechanisms through which early environmental effects may be mediated. These studies may inform the optimum timing and design for early preventive interventions aimed at reducing risk for psychopathology.

  20. First Language Attrition in the Speech of Dutch-English Bilinguals: The Case of Monozygotic Twin Sisters

    ERIC Educational Resources Information Center

    Mayr, Robert; Price, Sacha; Mennen, Ineke

    2012-01-01

    Recent years have seen a proliferation of research on attrition in L1 speech (de Leeuw, Mennen & Scobbie, in press; de Leeuw, Schmid & Mennen, 2010; Dmitrieva, Jongman & Sereno, 2010; Mennen, 2004). Adding to this line of inquiry, the present study investigates the speech of a 62-year-old bilingual monozygotic twin who emigrated to an L2-speaking…

  1. Degree and rate of growth discordance in dichorionic twins conceived by in vitro fertilization.

    PubMed

    Egic, Amira S; Mojovic, Donka V; Milovanovic, Zagorka M; Jurisic, Aleksandar B; Srbinovic, Ljubomir P; Krsmanovic, Suzana P; Karadzov-Orlic, Natasa T

    2014-01-01

    Objective. Our objective was to estimate degree and rate of discordant growth and its impact on perinatal outcome in dichorionic twin pregnancies conceived by in vitro fertilization (IVF) compared to those conceived spontaneously. Study Design. Growth discordance was defined as 90th percentiles for the study population. Adverse perinatal outcome was defined as 5-minute Apgar score <7 and/or admission to neonatal intensive care unit. Results. In the total study population of dichorionic twins (176 conceived by IVF and 215 spontaneously), 30% discordant growth represented the 90th percentile. After adjusting for gestational age, discordant twins conceived by IVF or spontaneously were at higher risk for adverse perinatal outcome (hazard ratio 4.4; 95% CI 2.4-8.3, P < 0.0001; hazard ratio 2.5; 95% CI 1.5-4.4, P = 0.001, resp.). Similar rates of 5-minute Apgar score <7, admission to neonatal intensive care unit, and delivery <34 weeks were found between discordant twins conceived by IVF and those conceived spontaneously. Conclusion. Dichorionic twins conceived by IVF are at similar risk for the rate and degree of discordant growth and adverse perinatal outcome compared to dichorionic twins conceived spontaneously.

  2. Sonar cephalometry in twin pregnancy: discordancy of the biparietal diameter after 28 weeks' gestation.

    PubMed

    Leveno, K J; Santos-Ramos, R; Duenhoelter, J H; Reisch, J S; Whalley, P J

    1980-11-15

    Sonar measured biparietal diameter (BPD) differences of twin paires were examined in 123 twin pregnancies at or beyond 28 weeks' gestation. Among 117 liveborn sets, the risk of a twin infant being small for gestational age was threefold greater when paired BPD differences were 5 mm or more compared to 4 mm or less. The incidence of fetal death increased from 2.7% for twin pairs with 0 to 6 mm BPD differences to 20% when the difference was 7 mm or more. Sonar cephalometry may be helpful in the antepartum evaluation of twin pregnancies, although detection of BPD discordancy does not preclude normal twin outcome.

  3. [CLINICAL CASE OF COMBINATION OF PRIMARY SCLEROSING CHOLANGITIS WITH NONSPECIFIC ULCERATIVE COLITIS IN TWINS MONOZYGOTIC].

    PubMed

    Gubergrits, N B; Belyayeva, N V; Klochkov, A Ye; Fomenko, P G; Lukashevich, G M

    2015-01-01

    The article presents discussion of basic hypotheses of pathogenesis of primary sclerosing cholangitis (PSC): genetically conditioned pathology, autoimmune pathology, result of inflammatory reaction in bile ducts, cholangiopathy. The authors presents a clinical case of monozygotic twins with association of PSC and nonspecific ulcerative colitis (NUC). The first twin had a severe course of PSC and mild course of NUC; he died due to bacterial complications of cholangitis. The second twin--patient B--had an opposite situation: severe course of NUC, while PSC was suspected only after determination of cholestasis biochemical markers. As soon as cholestasis was revealed, patients B was treated with Ursofalk and Budenofalk (2001). He received Salofalk as a remedy of basic therapy for NUC. Repeated liver biopsy (2005) showed no progression of PSC, but there were present minimal biochemical signs of cholestasis. So, it is necessary to investigate the first degree relatives of patients with PSC. The timely administered treatment in some cases gives the possibility of the control of the disease course.

  4. Presumed monozygotic twins develop following transfer of an in vitro-produced equine embryo

    PubMed Central

    ROBERTS, Melissa Ann; LONDON, Kelly; CAMPOS-CHILLÓN, Lino Fernando; ALTERMATT, Joy Lynn

    2015-01-01

    ABSTRACT An equine embryo produced by intracytoplasmic sperm injection (ICSI) was trans-cervically transferred to a recipient mare and pregnancy was confirmed via ultrasound examination on days 11, 12 and 15. On days 20 and 22, a single embryonic proper with a heartbeat was observed. On day 29, two embryos proper appeared during ultrasound examination, each possessing a heartbeat. Subsequent examinations on days 35 and 39 revealed continued viability and development of both embryos proper. On day 49, demise of both fetuses was present. Although no DNA analysis or post-partum examinations were performed, it is presumed that the fetuses were monozygotic twins based on membrane classification by ultrasound imaging as well as development occurring after the transfer of a single in vitro-produced embryo. PMID:26435682

  5. Risk Factors and Relationship of Cutaneous and Uveal Melanocytic Lesions in Monozygotic and Dizygotic Twin Pairs

    PubMed Central

    Varga, Anita; Szabó, Hajnalka; Orvos, Hajnalka; Kemény, Lajos; Oláh, Judit

    2016-01-01

    Background The similar genetic background of a pair of twins, and the similar environmental impacts to which they are exposed allow an exact and objective investigation of various constitutional and environmental factors in naevus development. As far as we are aware, this is the first published survey that simultaneously examines cutaneous and ocular pigmented lesions in an appreciable sample of identical and non-identical twins. Methods 172 pairs of twins of Caucasian origin were included in this study. A whole-body skin examination and a detailed ophthalmological examination were performed to determine the density of melanocytic lesions. A standardized questionnaire was used to assess the data relating to constitutional, sun exposure and other variables. Results A notably high proportion of the subjects (36.78%) manifested one or more clinically atypical melanocytic naevi (CAMNs), and approximately one-third (31.4%) of them at least one benign uveal pigmented lesion (BUPL). The incidence of iris freckles (IFs), iris naevi (INs) and choroidal naevi (CHNs) proved to be 25.35%, 5.98% and 3.52%, respectively. The interclass correlation coefficients for common melanocytic naevi (CMNs), CAMNs, and INs were 0.77, 0.76 and 0.86 in monozygotic twins, as compared with 0.5, 0.27 and 0.25 in dizygotic twin pairs, respectively. A statistically significant correlation was found between the prevalence of CAMNs and that of INs. Conclusions This significant correlation suggests the existence of a subgroup of Caucasian people with an increased susceptibility to both cutaneous and ocular naevus formation. There is accumulating evidence that, besides the presence of cutaneous atypical naevi, INs can serve as a marker of a predisposed phenotype at risk of uveal melanoma. The correlation between cutaneous and ocular pigmented lesions underlines the need for the adequate ophthalmological screening of subjects with CAMNs and INs. PMID:27486750

  6. Monozygotic Twin Pregnancy Associated with In Vitro Fertilization: Report and Revision of Three Cases Presented in a Clinic at 10,925 Feet Above Sea Level.

    PubMed

    Tominaga, Luis Vargas; Cáceres, Ricardo Pella; Lechuga, Alberto Vargas; Durán, Livia Bartolo; Vargas, Mariela Serrano

    2015-08-01

    3 cases of monozygotic twin pregnancies associated with IVF presented at Centro de Fertilidad y Ginecología del Sur. In this study, we describe the cases and review the literature, noting possible related factors.

  7. Growth hormone deficiency in monozygotic twins with autosomal dominant pseudohypoparathyroidism type Ib.

    PubMed

    Sano, Shinichiro; Iwata, Hiromi; Matsubara, Keiko; Fukami, Maki; Kagami, Masayo; Ogata, Tsutomu

    2015-01-01

    Pseudohypoparathyroidism (PHP) is associated with compromised signal transductions via PTH receptor (PTH-R) and other G-protein-coupled receptors including GHRH-R. To date, while GH deficiency (GHD) has been reported in multiple patients with PHP-Ia caused by mutations on the maternally expressed GNAS coding regions and in two patients with sporadic form of PHP-Ib accompanied by broad methylation defects of maternally derived GNAS differentially methylated regions (DMRs), it has not been identified in a patient with an autosomal dominant form of PHP-Ib (AD-PHP-Ib) accompanied by an STX16 microdeletion and an isolated loss of methylation (LOM) at exon A/B-DMR. We studied 5 4/12-year-old monozygotic twins with short stature (both -3.4 SD) and GHD (peak GH values, <6.0 μg/L after arginine and clonidine stimulations). Molecular studies revealed maternally derived STX16 microdeletions and isolated LOMs at exon A/B-DMR in the twins, confirming the diagnosis of AD-PHP-Ib. GNAS mutation was not identified, and neither mutation nor copy number variation was detected in GH1, POU1F1, PROP1, GHRHR, LHX3, LHX4, and HESX1 in the twins. The results, in conjunction with the previous finding that GNAS shows maternal expression in the pituitary, suggest that GHD of the twins is primarily ascribed to compromised GHRH-R signaling caused by AD-PTH-Ib. Thus, resistance to multiple hormones including GHRH should be considered in AD-PHP-Ib.

  8. Genome-wide DNA methylation variability in adolescent monozygotic twins followed since birth.

    PubMed

    Lévesque, Mélissa L; Casey, Kevin F; Szyf, Moshe; Ismaylova, Elmira; Ly, Victoria; Verner, Marie-Pier; Suderman, Matthew; Brendgen, Mara; Vitaro, Frank; Dionne, Ginette; Boivin, Michel; Tremblay, Richard E; Booij, Linda

    2014-10-01

    DNA methylation patterns are characterized by highly conserved developmental programs, but allow for divergent gene expression resulting from stochastic epigenetic drift or divergent environments. Genome-wide methylation studies in monozygotic (MZ) twins are providing insight into the extent of epigenetic variation that occurs, irrespective of genotype. However, little is known about the variability of DNA methylation patterns in adolescence, a period involving significant and rapid physical, emotional, social, and neurodevelopmental change. Here, we assessed genome-wide DNA methylation using the 450 K Illumina BeadChip in a sample of 37 MZ twin pairs followed longitudinally since birth to investigate: 1) the extent of variation in DNA methylation in identical genetic backgrounds in adolescence and; 2) whether these variations are randomly distributed or enriched in particular functional pathways. We also assessed stability of DNA methylation over 3-6 months to distinguish stable trait-like and variable state-like genes. A pathway analysis found high within-pair variability in genes associated with development, cellular mechanisms, tissue and cell morphology, and various disorders. Test-retest analyses performed in a sub-sample of 8 twin pairs demonstrated enrichment in gene pathways involved in organismal development, cellular growth and proliferation, cell signaling, and particular disorders. The variability found in functional gene pathways may plausibly underlie phenotypic differences in this adolescent MZ twin sample. Furthermore, we assessed stability of methylation over 3-6 months and found that some genes were stable while others were unstable, suggesting that the methylome remains dynamic in adolescence and that dynamic sites tend to be organized in certain gene pathways. PMID:25437055

  9. Genome-wide DNA methylation variability in adolescent monozygotic twins followed since birth

    PubMed Central

    Lévesque, Mélissa L; Casey, Kevin F; Szyf, Moshe; Ismaylova, Elmira; Ly, Victoria; Verner, Marie-Pier; Suderman, Matthew; Brendgen, Mara; Vitaro, Frank; Dionne, Ginette; Boivin, Michel; Tremblay, Richard E; Booij, Linda

    2014-01-01

    DNA methylation patterns are characterized by highly conserved developmental programs, but allow for divergent gene expression resulting from stochastic epigenetic drift or divergent environments. Genome-wide methylation studies in monozygotic (MZ) twins are providing insight into the extent of epigenetic variation that occurs, irrespective of genotype. However, little is known about the variability of DNA methylation patterns in adolescence, a period involving significant and rapid physical, emotional, social, and neurodevelopmental change. Here, we assessed genome-wide DNA methylation using the 450 K Illumina BeadChip in a sample of 37 MZ twin pairs followed longitudinally since birth to investigate: 1) the extent of variation in DNA methylation in identical genetic backgrounds in adolescence and; 2) whether these variations are randomly distributed or enriched in particular functional pathways. We also assessed stability of DNA methylation over 3–6 months to distinguish stable trait-like and variable state-like genes. A pathway analysis found high within-pair variability in genes associated with development, cellular mechanisms, tissue and cell morphology, and various disorders. Test-retest analyses performed in a sub-sample of 8 twin pairs demonstrated enrichment in gene pathways involved in organismal development, cellular growth and proliferation, cell signaling, and particular disorders. The variability found in functional gene pathways may plausibly underlie phenotypic differences in this adolescent MZ twin sample. Furthermore, we assessed stability of methylation over 3–6 months and found that some genes were stable while others were unstable, suggesting that the methylome remains dynamic in adolescence and that dynamic sites tend to be organized in certain gene pathways. PMID:25437055

  10. The variability of ovum pick-up response and in vitro embryo production from monozygotic twin cows.

    PubMed

    Machado, Sergio Abreu; Reichenbach, Horst-Dieter; Weppert, Myriam; Wolf, Eckhard; Gonçalves, Paulo Bayard Dias

    2006-02-01

    Oocytes were recovered by ovum pick up (OPU) from nine pairs of monozygotic twin German Simmental cows. The hypothesis was that there is less variability between identical twins versus among non-related individuals in the variation in the recovery of oocytes by OPU and in the efficiency of in vitro embryo production. Estrous cycles were synchronized with two doses of cloprostenol, 11 days apart. Beginning 3-4 days after synchronized estrus, OPU was done twice weekly (every 3 or 4 days; total of 11 sessions). The influence of repeated OPU on estrous cyclicity was established by estrus detection, plasma progesterone concentrations, and ovarian ultrasonography. There were no differences among days of collection for the number and quality of cumulus oocyte-complexes (COCs), and rates of cleavage and blastocyst formation. A total of 1,661 COCs, including 657 (39.6%) good-quality COCs, were recovered. From 1,457 (87.7%) cultured COCs, 827 zygotes cleaved and 314 blastocysts were produced on Day 7. The total number of COCs and the blastocyst rates varied among pairs of monozygotic twins; within pairs, only slight differences were observed. In conclusion, recovery of COCs and production of embryos had substantially less variation within pairs of monozygotic twins than among non-related cattle.

  11. Stability of Gut Enterotypes in Korean Monozygotic Twins and Their Association with Biomarkers and Diet

    PubMed Central

    Lim, Mi Young; Rho, Mina; Song, Yun-Mi; Lee, Kayoung; Sung, Joohon; Ko, GwangPyo

    2014-01-01

    Studies on the human gut microbiota have suggested that human individuals could be categorized into enterotypes based on the compositions of their gut microbial communities. Here, we report that the gut microbiota of healthy Koreans are clustered into two enterotypes, dominated by either Bacteroides (enterotype 1) or Prevotella (enterotype 2). More than 72% of the paired fecal samples from monozygotic twin pairs were assigned to the same enterotype. Our longitudinal analysis of these twins indicated that more than 80% of the individuals belonged to the same enterotype after about a 2-year interval. Microbial functions based on KEGG pathways were also divided into two clusters. For enterotype 2, 100% of the samples belonged to the same functional cluster, while for enterotype 1, approximately half of the samples belonged to each functional cluster. Enterotype 2 was significantly associated with long-term dietary habits that were high in dietary fiber, various vitamins, and minerals. Among anthropometrical and biochemical traits, the level of serum uric acid was associated with enterotype. These results suggest that host genetics as well as host properties such as long-term dietary patterns and a particular clinical biomarker could be important contributors to the enterotype of an individual. PMID:25482875

  12. Cedar pollen aggravates atopic dermatitis in childhood monozygotic twin patients with allergic rhino conjunctivitis.

    PubMed

    Murakami, Yukako; Matsui, Saki; Kijima, Akiko; Kitaba, Shun; Murota, Hiroyuki; Katayama, Ichiro

    2011-09-01

    We report a case of 7-year-old monozygotic twin patients with atopic dermatitis. The HLA haplotypes were HLA A2, A11, B27, B61, DR1, and DR4. Both serum IgE levels and cedar pollen radioallergosorbent test (RAST) scores were high in the twins (elder/younger sister: IgE: 5170/3980 IU/ml and Japansese cedar pollen: >100/64.0) in contrast to low mite and food RAST scores (Dermatophagoides Pterygonium; 0.59/0.4 and egg white 9.24/4.6). The patients showed positive immediate (20 min in both sisters) and delayed (24 hours in elder sister, 24, 48, 72 hours in younger sister) reactions to a scratch test with Japanese cedar pollen. Skin lesions on the face were aggravated and extended to the trunk and extremities during the Japanese cedar pollen season and gradually subsided in summer. Oral provocation with egg white or cow milk showed no exacerbations, and topical corticosteroid did not improve the eczema. In contrast, successful protection from severe scratching behaviors was achieved by use of topical anti-allergic eye drops and wearing nightgowns made by the mother. PMID:21430436

  13. Viruses in the faecal microbiota of monozygotic twins and their mothers.

    PubMed

    Reyes, Alejandro; Haynes, Matthew; Hanson, Nicole; Angly, Florent E; Heath, Andrew C; Rohwer, Forest; Gordon, Jeffrey I

    2010-07-15

    Viral diversity and life cycles are poorly understood in the human gut and other body habitats. Phages and their encoded functions may provide informative signatures of a human microbiota and of microbial community responses to various disturbances, and may indicate whether community health or dysfunction is manifest after apparent recovery from a disease or therapeutic intervention. Here we report sequencing of the viromes (metagenomes) of virus-like particles isolated from faecal samples collected from healthy adult female monozygotic twins and their mothers at three time points over a one-year period. We compared these data sets with data sets of sequenced bacterial 16S ribosomal RNA genes and total-faecal-community DNA. Co-twins and their mothers share a significantly greater degree of similarity in their faecal bacterial communities than do unrelated individuals. In contrast, viromes are unique to individuals regardless of their degree of genetic relatedness. Despite remarkable interpersonal variations in viromes and their encoded functions, intrapersonal diversity is very low, with >95% of virotypes retained over the period surveyed, and with viromes dominated by a few temperate phages that exhibit remarkable genetic stability. These results indicate that a predatory viral-microbial dynamic, manifest in a number of other characterized environmental ecosystems, is notably absent in the very distal intestine. PMID:20631792

  14. Analysis of the Covariance Structure of Digital Ridge Counts in the Offspring of Monozygotic Twins

    PubMed Central

    Cantor, Rita M.; Nance, Walter E.; Eaves, Lindon J.; Winter, Phyllis M.; Blanchard, Marsha M.

    1983-01-01

    Improved methods for analysis of covariance structures now permit the rigorous testing of multivariate genetic hypotheses. Using Jöreskog 's Lisrel IV computer program we have conducted a confirmatory factor analysis of dermal ridge counts on the individual fingers of 509 offspring of 107 monozygotic twin pairs. Prior to the initiation of the model-fitting procedure, the sex-adjusted ridge counts for the offspring of male and female twins were partitioned by a multivariate nested analysis of variance yielding five 10 x 10 variance-covariance matrices containing a total of 275 distinctly observed parameters with which to estimate latent sources of genetic and environmental variation and test hypotheses about the factor structure of those latent causes. To provide an adequate explanation for the observed patterns of covariation, it was necessary to include additive genetic, random environmental, epistatic and maternal effects in the model and a structure for the additive genetic effects which included a general factor and allowed for hand assymmetry and finger symmetry. The results illustrate the value of these methods for the analysis of interrelated metric traits. PMID:6682392

  15. Promoter Methylation of Glucocorticoid Receptor Gene Is Associated with Subclinical Atherosclerosis: a Monozygotic Twin Study

    PubMed Central

    Zhao, Jinying; An, Qiang; Goldberg, Jack; Quyyumi, Arshed A.; Vaccarino, Viola

    2015-01-01

    Objective Endothelial dysfunction assessed by brachial artery flow-mediated dilation (FMD) is a marker of early atherosclerosis. Glucocorticoid receptor gene (NR3C1) regulates many biological processes, including stress response, behavioral, cardiometabolic and immunologic functions. Genetic variants in NR3C1 have been associated with atherosclerosis and related risk factors. This study investigated the association of NR3C1 promoter methylation with FMD, independent of genetic and family-level environmental factors. Methods We studied 84 middle-aged, male-male monozygotic twin pairs recruited from the Vietnam Era Twin Registry. Brachial artery FMD was measured by ultrasound. DNA methylation levels at 22 CpG residues in the NR3C1 exon 1F promoter region were quantified by bisulfite pyrosequencing in genomic DNA isolated from peripheral blood leukocytes. Co-twin control analyses were conducted to examine the association of methylation variation with FMD, adjusting for smoking, physical activity, body mass index, lipids, blood pressure, fasting glucose, and depressive symptoms. Multiple testing was corrected using the false discovery rate. Results Mean methylation level across the 22 studied CpG sites was 2.02%. Methylation alterations at 12 out of the 22 CpG residues were significantly associated with FMD. On average, a 1% increase in the intra-pair difference in mean DNA methylation was associated with 2.83% increase in the intra-pair difference in FMD (95% CI: 1.46-4.20; P <0.0001) after adjusting for risk factors and multiple testing. Conclusion Methylation variation in NR3C1 exon 1F promoter significantly influences subclinical atherosclerosis, independent of genetic, early family environmental and other risk factors. PMID:26186654

  16. Genome-wide methylation study on depression: differential methylation and variable methylation in monozygotic twins

    PubMed Central

    Córdova-Palomera, A; Fatjó-Vilas, M; Gastó, C; Navarro, V; Krebs, M-O; Fañanás, L

    2015-01-01

    Depressive disorders have been shown to be highly influenced by environmental pathogenic factors, some of which are believed to exert stress on human brain functioning via epigenetic modifications. Previous genome-wide methylomic studies on depression have suggested that, along with differential DNA methylation, affected co-twins of monozygotic (MZ) pairs have increased DNA methylation variability, probably in line with theories of epigenetic stochasticity. Nevertheless, the potential biological roots of this variability remain largely unexplored. The current study aimed to evaluate whether DNA methylation differences within MZ twin pairs were related to differences in their psychopathological status. Data from the Illumina Infinium HumanMethylation450 Beadchip was used to evaluate peripheral blood DNA methylation of 34 twins (17 MZ pairs). Two analytical strategies were used to identify (a) differentially methylated probes (DMPs) and (b) variably methylated probes (VMPs). Most DMPs were located in genes previously related to neuropsychiatric phenotypes. Remarkably, one of these DMPs (cg01122889) was located in the WDR26 gene, the DNA sequence of which has been implicated in major depressive disorder from genome-wide association studies. Expression of WDR26 has also been proposed as a biomarker of depression in human blood. Complementarily, VMPs were located in genes such as CACNA1C, IGF2 and the p38 MAP kinase MAPK11, showing enrichment for biological processes such as glucocorticoid signaling. These results expand on previous research to indicate that both differential methylation and differential variability have a role in the etiology and clinical manifestation of depression, and provide clues on specific genomic loci of potential interest in the epigenetics of depression. PMID:25918994

  17. Population based study of prevalence of islet cell autoantibodies in monozygotic and dizygotic Danish twin pairs with insulin dependent diabetes mellitus.

    PubMed Central

    Petersen, J. S.; Kyvik, K. O.; Bingley, P. J.; Gale, E. A.; Green, A.; Dyrberg, T.; Beck-Nielsen, H.

    1997-01-01

    OBJECTIVE: To study the comparative importance of environment and genes in the development of islet cell autoimmunity associated with insulin dependent diabetes mellitus. DESIGN: Population based study of diabetic twins. SETTING: Danish population. SUBJECTS: 18 monozygotic and 36 dizygotic twin pairs with one or both partners having insulin dependent diabetes. MAIN OUTCOME MEASURES: Presence of islet cell antibodies, insulin autoantibodies, and autoantibodies to glutamic acid decarboxylase (GAD65) in serum samples from twin pairs 10 years (range 0-30 years) and 9.5 years (2-30 years) after onset of disease. RESULTS: In those with diabetes the prevalence of islet cell antibodies, insulin autoantibodies, and autoantibodies to glutamic acid decarboxylase in the 26 monozygotic twins was 38%, 85%, and 92%, respectively, and in the dizygotic twins was 57%, 70%, and 57%, respectively. In those without diabetes the proportions were 20%, 50%, and 40% in the 10 monozygotic twins and 26%, 49%, and 40% in the 35 dizygotic twins. CONCLUSION: There is no difference between the prevalence of islet cell autoantibodies in dizygotic and monozygotic twins without diabetes, suggesting that islet cell autoimmunity is environmentally rather than genetically determined. Furthermore, the prevalence of islet cell antibodies was higher in the non-diabetic twins than in other first degree relatives of patients with insulin dependent diabetes. This implies that the prenatal or early postnatal period during which twins are exposed to the same environment, in contrast with that experienced by first degree relatives, is of aetiological importance. PMID:9169400

  18. Impact of the genome on the epigenome is manifested in DNA methylation patterns of imprinted regions in monozygotic and dizygotic twins.

    PubMed

    Coolen, Marcel W; Statham, Aaron L; Qu, Wenjia; Campbell, Megan J; Henders, Anjali K; Montgomery, Grant W; Martin, Nick G; Clark, Susan J

    2011-01-01

    One of the best studied read-outs of epigenetic change is the differential expression of imprinted genes, controlled by differential methylation of imprinted control regions (ICRs). To address the impact of genotype on the epigenome, we performed a detailed study in 128 pairs of monozygotic (MZ) and 128 pairs of dizygotic (DZ) twins, interrogating the DNA methylation status of the ICRs of IGF2, H19, KCNQ1, GNAS and the non-imprinted gene RUNX1. While we found a similar overall pattern of methylation between MZ and DZ twins, we also observed a high degree of variability in individual CpG methylation levels, notably at the H19/IGF2 loci. A degree of methylation plasticity independent of the genome sequence was observed, with both local and regional CpG methylation changes, discordant between MZ and DZ individual pairs. However, concordant gains or losses of methylation, within individual twin pairs were more common in MZ than DZ twin pairs, indicating that de novo and/or maintenance methylation is influenced by the underlying DNA sequence. Specifically, for the first time we showed that the rs10732516 [A] polymorphism, located in a critical CTCF binding site in the H19 ICR locus, is strongly associated with increased hypermethylation of specific CpG sites in the maternal H19 allele. Together, our results highlight the impact of the genome on the epigenome and demonstrate that while DNA methylation states are tightly maintained between genetically identical and related individuals, there remains considerable epigenetic variation that may contribute to disease susceptibility. PMID:21991322

  19. Health-Related Findings Among Twin Pairs Discordant for Leisure-Time Physical Activity for 32 Years: The TWINACTIVE Study Synopsis.

    PubMed

    Leskinen, Tuija; Kujala, Urho M

    2015-06-01

    We are lacking very long-term and controlled intervention studies investigating the effects of habitual physical activity on health-related factors. To address this gap, we performed a natural experiment by identifying same-sex twin pairs in which the co-twins of each pair differed with respect to leisure-time physical-activity habits throughout their adult life. Our criterion for the discordance was that the same co-twin had a higher leisure time-activity volume than that of the other member of the pair at the majority -- if not all -- of the follow-up time points according to reported/interviewed physical-activity data. Overall, we identified and conducted multidimensional health-related measurements (including fitness, body composition, cardiometabolic risk factor levels, bone and arterial status, and exercise motivation) of 16 twin pairs (seven monozygotic (MZ) and nine dizygotic (DZ) pairs, mean age 60 years) who had persistent discordance in leisure-time physical-activity habits over three decades (TWINACTIVE study). In our discordant-pair study design, after adjusting for sequence-level genes, both systemic-level metabolic, and site-specific structural findings differed significantly in the pairwise analysis in MZ pairs only. These findings included intrapair differences in accumulated fat depots and structure of heart, arteries, and bones. In addition, our study revealed intrapair differences in metabolic and regulatory pathways, which may partly explain the mechanistic links between long-term physical activity, phenotypic changes, and decreased risk of cardiometabolic diseases. PMID:25906784

  20. Associations of Mother's and Father's Parenting Practices with Children's Observed Social Reticence in a Competitive Situation: A Monozygotic Twin Difference Study

    ERIC Educational Resources Information Center

    Guimond, Fanny-Alexandra; Brendgen, Mara; Forget-Dubois, Nadine; Dionne, Ginette; Vitaro, Frank; Tremblay, Richard E.; Boivin, Michel

    2012-01-01

    This study used the monozygotic (MZ) twin difference method to examine whether the unique environmental effects of maternal and paternal overprotection and hostility at the age of 30 months predict twins' observed social reticence in a competitive situation in kindergarten, while controlling for the effect of family-wide influences, including…

  1. A longitudinal investigation of the associations among parenting, deviant peer affiliation, and externalizing behaviors: a monozygotic twin differences design.

    PubMed

    Hou, Jinqin; Chen, Zhiyan; Natsuaki, Misaki N; Li, Xinying; Yang, Xiaodong; Zhang, Jie; Zhang, Jianxin

    2013-06-01

    Non-shared parenting and deviant peer affiliation are linked to differences in externalizing behaviors between twins. However, few studies have examined these two non-shared environments simultaneously. The present study examined the transactional roles of differential parenting (i.e., warmth and hostility) and deviant peer affiliation on monozygotic (MZ) twin differences in externalizing behaviors using a two-wave longitudinal study of twins and their parents. The sample consisted of 520 pairs of MZ twins (46.5% males, 53.5% females), with a mean age of 13.86 years (SD = 2.10) at the T1 assessment, residing in Beijing, China. The association between non-shared hostility in parenting and adolescent externalizing behaviors was mainly explained by a child-driven effect whereby the twin with a higher level of externalizing behaviors than his or her co-twin was more likely to receive more hostility from the parents. Similarly, the relationship between deviant peer affiliation and adolescent externalizing behaviors supported the selection effect whereby the twin with a higher level of externalizing behaviors than his or her co-twin was more likely to affiliate with deviant peers. The theoretical and practical implications of these findings are discussed.

  2. [Prenatal diagnosis of five cases of monochorionic-diamniotic twins discordant for karyotype analysis].

    PubMed

    Wu, Jianzhu; Zhou, Yi; Lin, Shaobin; Chen, Baojiang; Xie, Yingjun

    2015-10-01

    OBJECTIVE To explore the mechanism and diagnostic method for monochorionic-diamniotic twins discordant for karyotype analysis. METHODS Dual amniocentesis was performed on five pairs of monochorionic-diamniotic twins, which all consisted of a normal twin and one with multiple malformations revealed by ultrasound. Karyotype analysis was performed on amniocytes derived from each of the twins. Zygosity was also determined with DNA extracted from amniocytes with 16 polymorphic microsatellite markers. RESULTS Three cases of 45,X, one case of 47,XX,+9 and one case of 47,XY,+18 were detected among the abnormal twins, while the normal fetuses all had a normal karyotype. DNA analysis suggested that, in all cases, the twins have shared the 16 polymorphic microsatellite markers, which confirmed their monozygosity. CONCLUSION Monochorionic-diamniotic twins may be discordant for karyotyping, for which anaphase lagging, chromosomal non-disjunction and trisomy rescue may be the underlying reasons. As a simple method, dual amniocentesis can be used to obtain amniotic fluid samples for karyotype analysis and determination of zygosity for such twins. PMID:26418994

  3. Gut microbiomes of Malawian twin pairs discordant for kwashiorkor

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Kwashiorkor, an enigmatic form of severe acute malnutrition, is the consequence of inadequate nutrient intake plus additional environmental insults. To investigate the role of the gut microbiome, we studied 317 Malawian twin pairs during the first 3 years of life. During this time, half of the twin ...

  4. Congenital Kyphoscoliosis in Monozygotic Twins: Ten-Year Follow-up Treated by Posterior Vertebral Column Resection (PVCR)

    PubMed Central

    Chang, Dong-Gune; Yang, Jae Hyuk; Lee, Jung-Hee; Kim, Young-Hoon; Kim, Jin-Hyok; Suh, Seung-Woo; Ha, Kee-Yong; Suk, Se-Il

    2016-01-01

    Abstract The etiology of congenital scoliosis and its development remains unclear and has not yet been fully identified, even there are theories that congenital scoliosis could be derived from the failure of formation or failure of segmentation, which are etiologically heterogeneous with genetic, epigenetic, and environmental factors contributing to their occurrence. We reported a case of long-term follow-up after posterior vertebral column resection (PVCR) in both identical twins with similar congenital kyphoscoliosis at thoracolumbar levels. Twin I had been noticed by his parents to have asymmetry of his back at age 5 years, but no treatment was given. Twin II was first noticed to have a spinal problem at 11 years of age by his parents. Overtime, spine of both twins became further deviated to the left with kyphosis and was referred to our hospital. Both monozygotic twins were treated by PVCR and satisfactory results were demonstrated at 10-year follow-up. This case is the first report on the surgical treatment with PVCR, almost simultaneously, in both identical twins who had similar congenital vertebral anomalies causing kyphoscoliosis. Both identical twins with congenital kyphoscoliosis had undergone surgical correction by PVCR, anterior support with a mesh cage and posterior fusion using pedicle screws at the age of 14 years and achieved a satisfactory correction and a stable spine without curve progression with 10-year follow-up. PMID:27124052

  5. De novo deletion of chromosome 11q12.3 in monozygotic twins affected by Poland Syndrome

    PubMed Central

    2014-01-01

    Background Poland Syndrome (PS) is a rare disorder characterized by hypoplasia/aplasia of the pectoralis major muscle, variably associated with thoracic and upper limb anomalies. Familial recurrence has been reported indicating that PS could have a genetic basis, though the genetic mechanisms underlying PS development are still unknown. Case presentation Here we describe a couple of monozygotic (MZ) twin girls, both presenting with Poland Syndrome. They carry a de novo heterozygous 126 Kbp deletion at chromosome 11q12.3 involving 5 genes, four of which, namely HRASLS5, RARRES3, HRASLS2, and PLA2G16, encode proteins that regulate cellular growth, differentiation, and apoptosis, mainly through Ras-mediated signaling pathways. Conclusions Phenotype concordance between the monozygotic twin probands provides evidence supporting the genetic control of PS. As genes controlling cell growth and differentiation may be related to morphological defects originating during development, we postulate that the observed chromosome deletion could be causative of the phenotype observed in the twin girls and the deleted genes could play a role in PS development. PMID:24885342

  6. Differentially Methylated Genomic Regions in Birth-Weight Discordant Twin Pairs.

    PubMed

    Chen, Mubo; Baumbach, Jan; Vandin, Fabio; Röttger, Richard; Barbosa, Eudes; Dong, Mingchui; Frost, Morten; Christiansen, Lene; Tan, Qihua

    2016-03-01

    Poor nutrition during critical growth phases may alter the structural and physiologic development of vital organs thus "programming" the susceptibility to adult-onset diseases and disease-related health conditions. Epigenome-wide association studies have been performed in birth-weight discordant twin pairs to find evidence for such "programming" effects, but no significant results emerged. We further investigated this issue using a new computational approach: Instead of probing single genomic sites for significant alterations in epigenetic marks, we scan for differentially methylated genomic regions. Whole genome DNA methylation levels were measured in whole blood from 150 pairs of adult identical twins discordant for birth-weight. Intrapair differential DNA methylation was associated with qualitative (large or small) and quantitative (percentage) birth-weight discordance at each genomic site using regression models adjusting for age and sex. Based on the regression results, genomic regions with consistent alteration patterns of DNA methylation were located and tested for significant robustness using computational permutation tests. This yielded an interesting genomic region on chromosome 1, which is significantly differentially methylated for quantitative birth-weight discordance. The region covers two genes (TYW3 and CRYZ) both reportedly associated with metabolism. We conclude that prenatal conditions for birth-weight discordance may result in persistent epigenetic modifications potentially affecting even adult health. PMID:26831219

  7. Perinatal Outcome of Discordant Anomalous Twins: A Single-Center Experience in a Developing Country.

    PubMed

    Fernandes, Tatiana R M M; Carvalho, Paulo R N; Flosi, Fernanda B; Baião, Ana Elisa R; Junior, Sant Claire G

    2016-08-01

    A dramatic increase in twin pregnancies has been observed in the past few decades, primarily related to assisted reproductive techniques (ART) and increased average maternal age during pregnancy. Multiple pregnancies, compared to singleton pregnancies, are associated with greater perinatal morbidity and mortality. The present study evaluated the perinatal outcomes of pregnancies with discordant anomalous twins in a tertiary maternity ward in a developing country. Data were retrospectively collected from the Instituto Fernandes Figueira/FIOCRUZ, Brazil between January 2002 and December 2014. We identified 74 twin pregnancies with discordant anomalous twins. Final data analysis was based on 40 pregnancies. Congenital defects were classified according to the International Classification of Diseases: ICD-10: the digestive system was responsible in 27 (34%) cases; the central nervous system was responsible in 18 (22%) cases; the urinary tract was responsible in 14 (17%) cases; and the circulatory system was responsible in 14 (17%) cases. A total of 19 deaths occurred during the study period, and delivery before 30.4 weeks was a significant prediction of fetal death (p = .01). The presence of hydrops in the affected fetus was related to a higher number of deaths in healthy fetuses and contributed to a worse prognosis. The presence of this condition was the cause of 12 (55.6%) deaths in healthy fetuses. A 10 times higher risk of death of a normal co-twin was observed in cases of death of the anomalous twin (p = .002, OR 10.55, 95% CI: 1.9-58.52). PMID:27321141

  8. Thyroid hypoplasia as a cause of congenital hypothyroidism in monozygotic twins concordant for Rubinstein-Taybi syndrome.

    PubMed

    Akın, Mustafa Ali; Güneş, Tamer; Akın, Leyla; Çoban, Dilek; Oncu, Sena Kara; Kiraz, Aslıhan; Kurtoğlu, Selim

    2011-01-01

    Rubinstein-Taybi syndrome (RSTS), a genetic disorder characterized by growth retardation, mental deficiency, dysmorphic face, broad thumbs and large toes, generally affects monozygotic twins concordantly. Thyroid hypoplasia (TH) is a common cause of congenital hypothyroidism (CH) and often accompanies dysmorphic syndromes. A pair of female twins were admitted to our neonatology unit 16 hours after delivery. They were born at 35 weeks of gestation. Both twins had an unusual dysmorphic facial appearance with microcephaly, as well as broad short thumbs and large toes. Based on the presence of characteristic dysmorphic features, the twins were diagnosed as RSTS. Thyroid function tests in the first twin revealed the following results: free thyroxine (T4) 8.4 pg/mL, thyrotropin (TSH) 4.62 mIU/L, thyroglobulin (TG) 213.24 ng/mL and a normal level of urinary iodine excretion (UIE). Thyroid function test results in the second twin in the second week were: free T4 5.9 pg/mL, TSH 9.02 mIU/L, TG 204.87 ng/mL, and normal UIE levels. Thyroid volumes were 0.36 mL and 0.31 mL in the first and second twin, respectively. TH was confirmed by technetium 99 m pertechnetate thyroid scans in both infants. Thyroid function tests normalized with L-thyroxine replacement therapy (10 μg/kg/day) around the end of the 3(rd) week of life. The infants were discharged planning their follow-up by both endocrinology and cardiology units. The rarity of cases of twins with RSTS (concordant) co-existing with CH led us to present this report. PMID:21448332

  9. Cortex mapping reveals regionally specific patterns of genetic and disease-specific gray-matter deficits in twins discordant for schizophrenia.

    PubMed

    Cannon, Tyrone D; Thompson, Paul M; van Erp, Theo G M; Toga, Arthur W; Poutanen, Veli-Pekka; Huttunen, Matti; Lonnqvist, Jouko; Standerskjold-Nordenstam, Carl-Gustav; Narr, Katherine L; Khaledy, Mohammad; Zoumalan, Chris I; Dail, Rajneesh; Kaprio, Jaakko

    2002-03-01

    The symptoms of schizophrenia imply disruption to brain systems supporting higher-order cognitive activity, but whether these systems are impacted differentially against a background of diffuse cortical gray-matter deficit remains ambiguous. Some unaffected first-degree relatives of schizophrenics also manifest cortical gray-matter deficits, but it is unclear whether these changes are isomorphic with those in patients, and the answer is critical to understanding the neurobiological conditions necessary for disease expression given a predisposing genotype. Here we report three-dimensional cortical surface maps (probabilistic atlases matching subjects' anatomy point by point throughout cortex) in monozygotic (MZ) and dizygotic (DZ) twins discordant for chronic schizophrenia along with demographically matched control twins. A map encoding the average differences between schizophrenia patients and their unaffected MZ co-twins revealed deficits primarily in dorsolateral prefrontal cortex, superior temporal gyrus, and superior parietal lobule. A map encoding variation associated with genetic proximity to a patient (MZ co-twins > DZ co-twins > control twins) isolated deficits primarily in polar and dorsolateral prefrontal cortex. In each case, the statistical significance was confirmed through analysis of 10,000 Monte Carlo permutations, and the remaining cortex was shown to be significantly less affected by contrast analysis. The disease-related deficits in gray matter were correlated with measures of symptom severity and cognitive dysfunction but not with duration of illness or antipsychotic drug treatment. Genetic and disease-specific influences thus affect gray matter in partially nonoverlapping areas of predominantly heteromodal association cortex, changes that may act synergistically in producing overt behavioral features of the disorder. PMID:11867725

  10. Gut DNA viromes of Malawian twins discordant for severe acute malnutrition.

    PubMed

    Reyes, Alejandro; Blanton, Laura V; Cao, Song; Zhao, Guoyan; Manary, Mark; Trehan, Indi; Smith, Michelle I; Wang, David; Virgin, Herbert W; Rohwer, Forest; Gordon, Jeffrey I

    2015-09-22

    The bacterial component of the human gut microbiota undergoes a definable program of postnatal development. Evidence is accumulating that this program is disrupted in children with severe acute malnutrition (SAM) and that their persistent gut microbiota immaturity, which is not durably repaired with current ready-to-use therapeutic food (RUTF) interventions, is causally related to disease pathogenesis. To further characterize gut microbial community development in healthy versus malnourished infants/children, we performed a time-series metagenomic study of DNA isolated from virus-like particles (VLPs) recovered from fecal samples collected during the first 30 mo of postnatal life from eight pairs of mono- and dizygotic Malawian twins concordant for healthy growth and 12 twin pairs discordant for SAM. Both members of discordant pairs were sampled just before, during, and after treatment with a peanut-based RUTF. Using Random Forests and a dataset of 17,676 viral contigs assembled from shotgun sequencing reads of VLP DNAs, we identified viruses that distinguish different stages in the assembly of the gut microbiota in the concordant healthy twin pairs. This developmental program is impaired in both members of SAM discordant pairs and not repaired with RUTF. Phage plus members of the Anelloviridae and Circoviridae families of eukaryotic viruses discriminate discordant from concordant healthy pairs. These results disclose that apparently healthy cotwins in discordant pairs have viromes associated with, although not necessarily mediators, of SAM; as such, they provide a human model for delineating normal versus perturbed postnatal acquisition and retention of the gut microbiota's viral component in populations at risk for malnutrition.

  11. Gut DNA viromes of Malawian twins discordant for severe acute malnutrition

    PubMed Central

    Reyes, Alejandro; Blanton, Laura V.; Cao, Song; Zhao, Guoyan; Manary, Mark; Trehan, Indi; Smith, Michelle I.; Wang, David; Virgin, Herbert W.; Rohwer, Forest; Gordon, Jeffrey I.

    2015-01-01

    The bacterial component of the human gut microbiota undergoes a definable program of postnatal development. Evidence is accumulating that this program is disrupted in children with severe acute malnutrition (SAM) and that their persistent gut microbiota immaturity, which is not durably repaired with current ready-to-use therapeutic food (RUTF) interventions, is causally related to disease pathogenesis. To further characterize gut microbial community development in healthy versus malnourished infants/children, we performed a time-series metagenomic study of DNA isolated from virus-like particles (VLPs) recovered from fecal samples collected during the first 30 mo of postnatal life from eight pairs of mono- and dizygotic Malawian twins concordant for healthy growth and 12 twin pairs discordant for SAM. Both members of discordant pairs were sampled just before, during, and after treatment with a peanut-based RUTF. Using Random Forests and a dataset of 17,676 viral contigs assembled from shotgun sequencing reads of VLP DNAs, we identified viruses that distinguish different stages in the assembly of the gut microbiota in the concordant healthy twin pairs. This developmental program is impaired in both members of SAM discordant pairs and not repaired with RUTF. Phage plus members of the Anelloviridae and Circoviridae families of eukaryotic viruses discriminate discordant from concordant healthy pairs. These results disclose that apparently healthy cotwins in discordant pairs have viromes associated with, although not necessarily mediators, of SAM; as such, they provide a human model for delineating normal versus perturbed postnatal acquisition and retention of the gut microbiota’s viral component in populations at risk for malnutrition. PMID:26351661

  12. DNA methylation profiling in breast cancer discordant identical twins identifies DOK7 as novel epigenetic biomarker

    PubMed Central

    Esteller, Manel

    2013-01-01

    Using whole blood from 15 twin pairs discordant for breast cancer and high-resolution (450K) DNA methylation analysis, we identified 403 differentially methylated CpG sites including known and novel potential breast cancer genes. Confirming the results in an independent validation cohort of 21 twin pairs determined the docking protein DOK7 as a candidate for blood-based cancer diagnosis. DNA hypermethylation of the promoter region was also seen in primary breast cancer tissues and cancer cell lines. Hypermethylation of DOK7 occurs years before tumor diagnosis, suggesting a role as a powerful epigenetic blood-based biomarker as well as providing insights into breast cancer pathogenesis. PMID:23054610

  13. DNA methylation profiling in breast cancer discordant identical twins identifies DOK7 as novel epigenetic biomarker.

    PubMed

    Heyn, Holger; Carmona, F Javier; Gomez, Antonio; Ferreira, Humberto J; Bell, Jordana T; Sayols, Sergi; Ward, Kirsten; Stefansson, Olafur A; Moran, Sebastian; Sandoval, Juan; Eyfjord, Jorunn E; Spector, Tim D; Esteller, Manel

    2013-01-01

    Using whole blood from 15 twin pairs discordant for breast cancer and high-resolution (450K) DNA methylation analysis, we identified 403 differentially methylated CpG sites including known and novel potential breast cancer genes. Confirming the results in an independent validation cohort of 21 twin pairs determined the docking protein DOK7 as a candidate for blood-based cancer diagnosis. DNA hypermethylation of the promoter region was also seen in primary breast cancer tissues and cancer cell lines. Hypermethylation of DOK7 occurs years before tumor diagnosis, suggesting a role as a powerful epigenetic blood-based biomarker as well as providing insights into breast cancer pathogenesis. PMID:23054610

  14. A monozygotic twin pair with β-thalassemia carrier status in a Dudh Kharia tribal family of Orissa

    PubMed Central

    Balgir, R. S.

    2007-01-01

    -thalassemia (trait) genotypes with identical clinical manifestations and hematological profile of the twin sons under similar environmental conditions, hence they were labeled as identical monozygotic twins. CONCLUSIONS: It is a rare occasion when a single pregnancy carries either one or two abnormal genotypes at a time in a womb in human beings. Monozygotic twins are genetically alike and provide appraisal of the expression of identical genotype under the different environmental conditions. PMID:21957337

  15. Phenotypic discordance in a family with monozygotic twins and non-syndromic cleft lip and palate

    SciTech Connect

    Wyszynski, D.F. |; Lewanda, A.F. |; Beaty, T.H.

    1996-12-30

    Despite considerable research, the cause of non-syndromic cleft lip with or without cleft palate (NSCLP) is still an enigma. Case-control and cohort studies have searched for environmental factors that might influence the development of this common malformation, such as maternal cigarette smoking, periconceptional supplementation of folic acid and multivitamins, agricultural chemical use, and place of residence, among others. However, these studies are subject to numerous biases, and their results have often been contradictory and inconclusive. 41 refs., 1 fig.

  16. A Discordant Monozygotic Twin Design Shows Blunted Cortisol Reactivity among Bullied Children

    ERIC Educational Resources Information Center

    Ouellet-Morin, Isabelle; Danese, Andrea; Bowes, Lucy; Shakoor, Sania; Ambler, Antony; Pariante, Carmine M.; Papadopoulos, Andrew S.; Caspi, Avshalom; Moffitt, Terrie E.; Arseneault, Louise

    2011-01-01

    Objective: Childhood adverse experiences are known to engender persistent changes in stress-related systems and brain structures involved in mood, cognition, and behavior in animal models. Uncertainty remains about the causal effect of early stressful experiences on physiological response to stress in human beings, as the impact of these…

  17. Genes and Memory: The Neuroanatomical Correlates of Emotional Memory in Monozygotic Twin Discordant for Schizophrenia

    ERIC Educational Resources Information Center

    Fahim, Cherine; Stip, Emmanuel; Mancini-Marie, Adham; Beauregard, Mario

    2004-01-01

    Background: Brain morphology and physiological measures in schizophrenia have yielded inconsistent results. This may be due in part to difficulties in ascertaining precisely to what degree each measure deviates from its genetically and environmentally determined potential level. We attempted to surmount this problem in a paradigm involving…

  18. Mapping corpus callosum morphology in twin pairs discordant for bipolar disorder.

    PubMed

    Bearden, Carrie E; van Erp, Theo G M; Dutton, Rebecca A; Boyle, Christina; Madsen, Sarah; Luders, Eileen; Kieseppa, Tuula; Tuulio-Henriksson, Annamari; Huttunen, Matti; Partonen, Timo; Kaprio, Jaakko; Lönnqvist, Jouko; Thompson, Paul M; Cannon, Tyrone D

    2011-10-01

    Callosal volume reduction has been observed in patients with bipolar disorder, but whether these deficits reflect genetic vulnerability to the illness remains unresolved. Here, we used computational methods to map corpus callosum abnormalities in a population-based sample of twin pairs discordant for bipolar disorder. Twenty-one probands with bipolar I disorder (mean age 44.4 ± 7.5 years; 48% female), 19 of their non-bipolar co-twins, and 34 demographically matched control twin individuals underwent magnetic resonance imaging. Three-dimensional callosal surface models were created to visualize its morphologic variability and to localize group differences. Neurocognitive correlates of callosal area differences were additionally investigated in a subsample of study participants. Bipolar (BPI) probands, but not their co-twins, showed significant callosal thinning and area reduction, most pronounced in the genu and splenium, relative to healthy twins. Altered callosal curvature was additionally observed in BPI probands. In bipolar probands and co-twins, genu and splenium midsagittal areas were significantly correlated with verbal processing speed and response inhibition. These findings suggest that aberrant connections between cortical regions--possibly reflecting decreased myelination of white matter tracts--may be involved in bipolar pathophysiology. However, findings of callosal thinning appear to be disease related, rather than reflecting genetic vulnerability to bipolar illness. PMID:21383237

  19. A Pair of Identical Twins Discordant for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Differ in Physiological Parameters and Gut Microbiome Composition

    PubMed Central

    Giloteaux, Ludovic; Hanson, Maureen R.; Keller, Betsy A.

    2016-01-01

    Patient: Male, 34 Final Diagnosis: ME/CFS Symptoms: Exertion intolerance • loss of functional capacity • pain • severe fatigue Medication: — Clinical Procedure: Cardiopulmonary exercise test Specialty: Sports Medicine Objective: Unknown ethiology Background: Patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) present with profound fatigue, flu-like symptoms, pain, cognitive impairment, orthostatic intolerance, post-exertional malaise (PEM), and exacerbation of some or all of the baseline symptoms. Case Report: We report on a pair of 34-year-old monozygotic twins discordant for ME/CFS, with WELL, the non-affected twin, and ILL, the affected twin. Both twins performed a two-day cardiopulmonary exercise test (CPET), preand post-exercise blood samples were drawn, and both provided stool samples for biochemical and molecular analyses. At peak exertion for both CPETs, ILL presented lower VO2peak and peak workload compared to WELL. WELL demonstrated normal reproducibility of VO2@ventilatory/anaerobic threshold (VAT) during CPET2, whereas ILL experienced an abnormal reduction of 13% in VAT during CPET2. A normal rise in lactate dehydrogenase (LDH), creatine kinase (CK), adrenocorticotropic hormone (ACTH), cortisol, creatinine, and ferritin content was observed following exercise for both WELL and ILL at each CPET. ILL showed higher increases of resistin, soluble CD40 ligand (sCD40L), and soluble Fas ligand (sFasL) after exercise compared to WELL. The gut bacterial microbiome and virome were examined and revealed a lower microbial diversity in ILL compared to WELL, with fewer beneficial bacteria such as Faecalibacterium and Bifidobacterium, and an expansion of bacteriophages belonging to the tailed dsDNA Caudovirales order. Conclusions: Results suggest dysfunctional immune activation in ILL following exercise and that prokaryotic viruses may contribute to mucosal inflammation and bacterial dysbiosis. Therefore, a two-day CPET and molecular

  20. Serial MR imaging and 1H-MR spectroscopy in monozygotic twins with Tay-Sachs disease.

    PubMed

    Imamura, A; Miyajima, H; Ito, R; Orii, K O

    2008-10-01

    Four-year-old monozygotic female twins with early onset Tay-Sachs disease are described. The sisters showed similar slowly progressive clinical symptoms and deterioration, however the younger sister also demonstrated intractable myoclonus in the right leg. The serial MR images and (1)H-MR spectroscopy of the brain were obtained in both twins. MR images showed high intensity on T (2)-weighted image in the bilateral white matter, however there were no signal changes in the basal ganglia and thalamus during any of the phases. The ratio of N-acetylaspartate (NAA)/creatine (Cr) was decreased in the both white matter lesions and the corpus striatum, and that of myoinositol (mI)/Cr was increased in the damaged white matter on MR spectroscopy. The elevation of the lactate peak was clearly demonstrated in the left basal ganglia of the younger sister; however it was not shown in cerebral lesions of the elder sister. Changes in metabolites on MR spectroscopy were closely linked to the respective clinical features of each twin. Follow-up examination by (1)H-MR spectroscopy is useful for the evaluation of neuronal changes in children with Tay-Sachs disease. PMID:19294598

  1. Quantifying familial influences on brain activation during the monetary incentive delay task: An adolescent monozygotic twin study

    PubMed Central

    Silverman, Merav H.; Krueger, Robert F.; Iacono, William G.; Malone, Stephen M.; Hunt, Ruskin H.; Thomas, Kathleen M.

    2014-01-01

    Although altered brain activation during reward tasks has been found in a number of heritable psychiatric disorders and health outcomes, the familial nature of reward-related brain activation remains unexplored. In this study, we investigated the degree to which the magnitude of mesocorticolimbic reward system signal intensities in anticipation of reward during the monetary incentive delay (MID) task was similar within forty-six pairs of adolescent, monozygotic twins. Significant within-pair correlations in brain activation during anticipation of gain were found in one third of the 18 reward-related regions investigated. These regions were the right nucleus accumbens, left and right posterior caudate, right anterior caudate, left insula, and anterior cingulate cortex. This serves as evidence for a shared familial contribution to individual differences in reward related brain activity in certain key reward processing regions. PMID:25101864

  2. A Longitudinal Investigation of the Relationship between Disordered Eating Attitudes and Behaviors and Parent-Child Conflict: A Monozygotic Twin Differences Design

    PubMed Central

    Spanos, Alexia; Klump, Kelly L.; Burt, S. Alexandra; McGue, Matt; Iacono, William G.

    2010-01-01

    Few studies have examined nonshared environmental risk factors for disordered eating, and none have done so using a longitudinal design. The current project employed a longitudinal, monozygotic twin differences design to examine parent-child conflict as a nonshared environmental risk factor for disordered eating. Participants included 468 monozygotic female twins (234 pairs) from the Minnesota Twin Family Study, followed every three years from ages 11 to 17. Twin differences in disordered eating were assessed with the Total Score, Body Dissatisfaction, Weight Preoccupation and Binge Eating subscales of the Minnesota Eating Behavior Survey. Differences in parent-child conflict were assessed with the Parental Environment Questionnaire. Cross-lagged models were used to examine longitudinal associations among these variables, controlling for within-age associations. Only the longitudinal association between twin differences in disordered eating at age 14 and differences in parent-child conflict at age 17 was significant; twin differences in disordered eating predicted later differences in parent-child conflict rather than the reverse. Findings suggest differences in parent-child conflict between genetically identical twins may be a consequence of, rather than a risk factor for, differences in disordered eating. PMID:20455602

  3. A longitudinal investigation of the relationship between disordered eating attitudes and behaviors and parent-child conflict: a monozygotic twin differences design.

    PubMed

    Spanos, Alexia; Klump, Kelly L; Burt, S Alexandra; McGue, Matt; Iacono, William G

    2010-05-01

    Few studies have examined nonshared environmental risk factors for disordered eating, and none have done so using a longitudinal design. The current project used a longitudinal, monozygotic twin differences design to examine parent-child conflict as a nonshared environmental risk factor for disordered eating. Participants included 468 monozygotic female twins (234 pairs) from the Minnesota Twin Family Study, who completed surveys every 3 years from ages 11 to 17 years. Twin differences in disordered eating were assessed with the Total Score, Body Dissatisfaction, Weight Preoccupation, and Binge Eating subscales of the Minnesota Eating Behavior Survey. Differences in parent-child conflict were assessed with the Parental Environment Questionnaire. Cross-lagged models were used to examine longitudinal associations among these variables, controlling for within-age associations. Only the longitudinal association between twin differences in disordered eating at age 14 years and differences in parent-child conflict at age 17 years were significant; twin differences in disordered eating predicted later differences in parent-child conflict rather than the reverse. Findings suggest differences in parent-child conflict between genetically identical twins may be a consequence of, rather than a risk factor for, differences in disordered eating.

  4. Associations between sleep habits and mental health status and suicidality in a longitudinal survey of monozygotic twin adolescents.

    PubMed

    Matamura, Misato; Tochigi, Mamoru; Usami, Satoshi; Yonehara, Hiromi; Fukushima, Masako; Nishida, Atsushi; Togo, Fumiharu; Sasaki, Tsukasa

    2014-06-01

    Several epidemiological studies have indicated that there is a relationship between sleep habits, such as sleep duration, bedtime and bedtime regularity, and mental health status, including depression and anxiety in adolescents. However, it is still to be clarified whether the relationship is direct cause-and-effect or mediated by the influence of genetic and other traits, i.e. quasi-correlation. To examine this issue, we conducted a twin study using a total of 314 data for monozygotic twins from a longitudinal survey of sleep habits and mental health status conducted in a unified junior and senior high school (grades 7-12), located in Tokyo, Japan. Three-level hierarchical linear model analysis showed that both bedtime and sleep duration had significant associations with the Japanese version of the 12-item General Health Questionnaire (GHQ-12) score, suicidal thoughts and the experience of self-harm behaviours when genetic factors and shared environmental factors, which were completely shared between co-twins, were controlled for. These associations were statistically significant even after controlling for bedtime regularity, which was also associated significantly with the GHQ-12 score. These suggest that the associations between sleep habits and mental health status were still statistically significant after controlling for the influence of genetic and shared environmental factors of twins, and that there may be a direct cause-and-effect in the relationship in adolescents. Thus, late bedtime and short sleep duration could predict subsequent development of depression and anxiety, including suicidal or self-injury risk. This suggests that poor mental health status in adolescents might be improved by health education and intervention concerning sleep and lifestyle habits.

  5. Parkinsonism in a pair of monozygotic CADASIL twins sharing the R1006C mutation: a transcranial sonography study.

    PubMed

    Ragno, Michele; Sanguigni, Sandro; Manca, Antonio; Pianese, Luigi; Paci, Cristina; Berbellini, Alfonso; Cozzolino, Valeria; Gobbato, Roberto; Peluso, Silvio; De Michele, Giuseppe

    2016-06-01

    Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common hereditary cerebral small vessel disease, is caused by mutations in the NOTCH3 gene on chromosome 19. Clinical manifestations of CADASIL include recurrent transient ischemic attacks, strokes, cognitive defects, epilepsy, migraine and psychiatric symptoms. Parkinsonian features have variably been reported in CADASIL patients, but only a few patients showed a clear parkinsonian syndrome. We studied two patients, a pair of monozygotic twins, carrying the R1006C mutation of the NOTCH3 gene and affected by a parkinsonian syndrome. For the first time in CADASIL patients, we used transcranial sonography (TCS) to assess basal ganglia abnormalities. TCS showed a bilateral hyperechogenic pattern of substantia nigra in one twin, and a right hyperechogenic pattern in the other. In both patients, lenticular nuclei showed a bilateral hyperechogenic pattern, and the width of the third ventricle was slightly increased. The TCS pattern found in our CADASIL patients is characteristic neither for Parkinson's disease, nor for vascular parkinsonism and seems to be specific and related to the disease-specific pathological features. PMID:26850715

  6. Discordance

    NASA Astrophysics Data System (ADS)

    Villa, I. M.; Hanchar, J. M.

    2013-12-01

    Half a century ago, discordant U-Pb ages of metamorphic zircon were viewed as Pb loss by diffusion. Various diffusionist schools of thought debated vigorously whether diffusion was episodic or continuous [1], but nobody questioned the reality of diffusive Pb loss. Only imaging by cathodoluminescence (CL) [2] and back-scattered electrons (BSE) [3] brought a paradigm change in U-Pb geochronology. In situ dating shows routinely accretion of young zircon rims onto older cores that never display Pb diffusion gradients across the interface. Other minerals (monazite, xenotime, etc.) show the same pattern: irregular patches of uniform age separated by sharp age gradients coinciding with petrologic boundaries. As U-Pb discordance is caused by diachronous, heterochemical mineral generations, zircon and monazite closure temperatures, and strict diffusionism, are irrelevant [4]. Knowing what to pay attention to, analytical protocols for U-Pb dating include both of the following: (i) CL/BSE characterization of phase mixtures; (ii) mass spectrometric analysis including U/Th ratios (and ideally trace element fingerprinting on the same fraction [5]). It is clear that the petrologic context is just as essential as mass spectrometry for accurate geochronology. The K-Ar community rarely uses imaging, and the tight context between microstructures, mineral chemistry, petrology and geochronology is missed. Yet the data would be clear if one looked for it. CL and/or BSE imaging and X-ray mapping of K-feldspar and micas is finding ubiquitous evidence of discrete patches of juxtaposed mineral generations. The Ca/Cl/K ratios in 39Ar-40Ar dating fulfill the same role as U/Th ratios in U-Pb dating for fingerprinting successive heterochemical mineral generations. Any linear correlation in a common-denominator three-isotope correlation diagram is certain evidence of binary mixing between heterochemical end-members. A correlation in a Ca/K vs Ar/K diagram requires two minerals having different

  7. Pyrosequencing of Plaque Microflora In Twin Children with Discordant Caries Phenotypes

    PubMed Central

    Zhang, Meng; Chen, Yongxing; Xie, Lingzhi; Li, Yuhong; Jiang, Han; Du, Minquan

    2015-01-01

    Despite recent successes in the control of dental caries, the mechanism of caries development remains unclear. To investigate the causes of dental decay, especially in early childhood caries, the supragingival microflora composition of 20 twins with discordant caries phenotypes were analyzed using high-throughput pyrosequencing. In addition, the parents completed a lifestyle questionnaire. A total of 228,789 sequencing reads revealed 10 phyla, 84 genera, and 155 species of microflora, the relative abundances of these strains varied dramatically among the children, Comparative analysis between groups revealed that Veillonella, Corynebacterium and Actinomyces were presumed to be caries-related genera, Fusobacterium, Kingella and Leptotrichia were presumed to be healthy-related genus, yet this six genera were not statistically significant (P>0.05). Moreover, a cluster analysis revealed that the microbial composition of samples in the same group was often dissimilar but that the microbial composition observed in twins was usually similar. Although the genetic and environmental factors that strongly influence the microbial composition of dental caries remains unknown, we speculate that genetic factors primarily influence the individual's susceptibility to dental caries and that environmental factors primarily regulate the microbial composition of the dental plaque and the progression to caries. By using improved twins models and increased sample sizes, our study can be extended to analyze the specific genetic and environmental factors that affect the development of caries. PMID:26524687

  8. Levels of Adipokines in Amniotic Fluid and Cord Blood Collected from Dichorionic-Diamniotic Twins Discordant for Fetal Growth

    PubMed Central

    Park, Joong Shin; Norwitz, Errol R.; Panyavatthanasinh, Sitthysack; Kim, Sun Min; Lee, JoonHo; Park, Chan-Wook; Kim, Byoung Jae; Jun, Jong Kwan

    2016-01-01

    Objective To compare the concentrations of adipokines in amniotic fluid (AF) and cord blood collected from discordant dichorionic-diamniotic (DCDA) twin fetuses. Study Design The study population included DCDA twins discordant for fetal growth (birth weight difference >10%) who either underwent mid-trimester amniocentesis for routine clinical indication (Cohort 1) or whose amniotic fluid was collected at the time of delivery (Cohort 2). In both cohorts, cord blood was collected at delivery. Results A total of 92 twin pairs were enrolled (n = 49 in Cohort 1; n = 43 in Cohort 2). In Cohort 1, the concentrations of adiponectin (median, 68.5 ng/mL vs 61.4 ng/mL; p<0.05) and leptin (median, 13.9 ng/mL vs 11.2 ng/mL; p<0.1) in mid-trimester AF were significantly higher in smaller compared with larger twins. In Cohort 2, the concentration of serpin E1 (median, 246.0 ng/mL vs 182.8 ng/mL; p<0.01) in AF at delivery was significantly higher in smaller twins, but no difference was noted in adiponectin and leptin concentrations. Levels of adiponectin (median, 10425.5 ng/mL vs 11552.0 ng/mL; p<0.005) and leptin (median, 2.1 ng/mL vs 2.6 ng/mL; p<0.005) were significantly lower in the cord blood of smaller twins whereas cord blood concentrations of serpin E1 (median, 15.5 ng/mL vs 13.3 ng/mL; p<0.05) was higher in the smaller twins. Conclusion In discordant DCDA twin pairs, concentrations of adiponectin, leptin, and serpin E1 in mid-trimester AF, AF at delivery, and cord blood at birth vary significantly but predictably between the smaller and larger twins. PMID:27135745

  9. Isolated corneal pseudodendrites as the initial manifestation of tyrosinemia type II in monozygotic twins.

    PubMed

    Kymionis, George D; Kankariya, Vardhaman P; Kontadakis, Georgios A; Ziakas, Nikolas G

    2012-05-08

    Fifteen-month-old twins presented with photophobia and bilateral corneal pseudodendrites, and tyrosinemia type II was suspected. Plasma tyrosine levels were elevated. After therapy with tyrosine-restricted diet, corneal lesions resolved. Bilateral pseudodendritic keratitis may be the initial or only manifestation of tyrosinemia type II.

  10. Phenotypic variability of R117H-CFTR expression within monozygotic twins.

    PubMed

    Waller, Michael D; Simmonds, Nicholas J

    2016-08-01

    Whilst cystic fibrosis is a monogenic condition, variation in phenotype exists for the same CFTR genotype, which is influenced by multiple genetic and non-genetic (environmental) factors. The R117H-CFTR mutation has variability directly relating to in cis poly-thymidine alleles, producing a differing spectrum of disease. This paper provides evidence of extreme phenotype variability - including fertility status - in the context of male monogenetic twins, discussing mechanisms and highlighting the diagnostic and treatment challenges. PMID:27364092

  11. A twin study on age-related macular degeneration.

    PubMed Central

    Meyers, S M

    1994-01-01

    A prospective twin study on age-related macular degeneration (AMD) recruited 83 monozygotic pairs, 28 dizygotic pairs, and one triplet set from 1986 through 1993. Zygosity was determined by genetic testing of red cell markers, HLA antigens, or specific DNA loci. There were no twin pairs in which I collected data on only one twin. To decrease ascertainment bias, after 1991 the recruitment notice did not mention AMD, and I did not ask about a history of eye disease before the eye examination. Because of this, twin pairs recruited from 1986 through 1991 were statistically analyzed separately from those after January 1, 1992. From 1986 through 1991, 23 twin pairs were recruited; 11 monozygotic and 2 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 9 monozygotic pairs with AMD were all concordant, and 1 dizygotic pair was discordant for basal laminar drusen. The concordance rate of AMD did not differ significantly between monozygotic and dizygotic twin pairs (P = .10) for 1986 through 1991. In 1992 and 1993, 88 twin pairs and one triplet set were recruited; 49 monozygotic and 19 dizygotic pairs had nonAMD retinal changes or no retinal abnormalities, 14 monozygotic pairs with AMD were all concordant, and 2 of 7 dizygotic pairs were concordant for AMD. The nonidentical triplets (1 with and 2 without AMD) were categorized as one of the discordant dizygotic pairs in the statistical evaluation. In nontwin age-matched (within 2 or 5 years of age) or age- and sex-matched sibling pairs the concordance rate of AMD ranged from 16% to 25%. The concordance rate of AMD was significantly higher in monozygotic than in dizygotic twins (P = .001) for 1992 and 1993. The concordance rate was higher for monozygotic twin pairs recruited in 1992 and 1993 than in any of the four subsets of nontwin age-method or age- and sex-matched sibling pairs (P < .0001). Overall, from 1986 through 1993, 23 of 23 monozygotic and 2 of 8 dizygotic twin pairs were concordant for AMD

  12. Fragile X syndrome and the (CGG)[sub n] mutation: Two families with discordant MZ twins

    SciTech Connect

    Kruyer, H.; Estivill, X.; Mila, M.; Ballesta, F.; Glover, G.; Carbonell, P. )

    1994-03-01

    The fragile X phenotype has been found, in the majority of cases, to be due to the expansion of a CGG repeat in the 5'UTR region of the FMR-1 gene, accompanied by methylation of the adjacent CpG island and inactivation of the FMR-1 gene. Although several important aspects of genetics of fragile X have been resolved, it remains to be elucidated at which stage in development the transition from the premutation to the full mutation occurs. The authors present two families in which discordance between two sets of MZ twins illustrates two important genetic points. In one family, two affected MZ brothers differed in the number of CGG repeats, demonstrating in vivo mitotic instability of this CGG repeat and suggesting that the transition to the full mutation occurred postzygotically. In the second family, two MZ sisters had the same number of repeats, but only one was mentally retarded. When the methylation status of the FMR-1 CpG island was studied, the authors found that the majority of normal chromosomes had been inactivated in the affected twin, thus leading to the expression of the fragile X phenotype. 29 refs., 3 figs., 1 tab.

  13. Dermatoglyphics in relation to brain volumes in twins concordant and discordant for bipolar disorder.

    PubMed

    Vonk, R; van der Schot, A C; van Baal, G C M; van Oel, C J; Nolen, W A; Kahn, R S

    2014-12-01

    Palmar and finger dermatoglyphics are formed between the 10th and the 17th weeks of gestation and their morphology can be influenced by genetic or environmental factors, interfering with normal intrauterine development. As both the skin and the brain develop from the same embryonal ectoderm, dermatoglyphic alterations may be informative for early abnormal neurodevelopmental processes in the brain. We investigated whether dermatoglyphic alterations are related to structural brain abnormalities in bipolar disorder and to what extent they are of a genetic and of an environmental origin. Dermatoglyphics and volumetric data from structural MRI were obtained in 53 twin pairs concordant or discordant for bipolar disorder and 51 healthy matched control twin pairs. Structural equation modeling was used. Bipolar disorder was significantly positively associated with palmar a-b ridge count (ABRC), indicating higher ABRC in bipolar patients (rph=.17 (CI .04-.30)). Common genes appear to be involved because the genetic correlation with ABRC was significant (rph-A=.21 (CI .05-.36). Irrespective of disease, ABRC showed a genetically mediated association with brain volume, indicated by a significant genetic correlation rph-A of respectively -.36 (CI -.52 to -.22) for total brain, -.34 (CI -.51 to -.16) total cortical volume, -.27 (CI -.43 to -.08) cortical gray matter and -.23 (CI -.41 to -.04) cortical white matter. In conclusion, a genetically determined abnormal development of the foetal ectoderm between the 10th and 15th week of gestation appears related to smaller brain volumes in (subjects at risk for) bipolar disorder.

  14. Celiac disease with Evans syndrome and isolated immune thrombocytopenia in monozygotic twins: a rare association.

    PubMed

    Roganovic, Jelena

    2016-04-01

    Celiac disease is a multisystem immune-mediated disorder caused by exposure to dietary gluten in genetically predisposed individuals. The clinical presentation is characterized by a multitude and diversity of symptoms and complications. The coexistence of celiac disease with other autoimmune disorders has been established, most frequently with type 1 diabetes mellitus and autoimmune thyroiditis. The association of celiac disease with immune-mediated hematologic conditions has been rarely reported. This case study describes a pair of identical twin sisters with celiac disease associated with Evans syndrome in one sibling, and with isolated immune thrombocytopenia in the other. PMID:27312169

  15. The impact of a consortium of fermented milk strains on the gut microbiome of gnotobiotic mice and monozygotic twins

    PubMed Central

    McNulty, Nathan P.; Yatsunenko, Tanya; Hsiao, Ansel; Faith, Jeremiah J.; Muegge, Brian D.; Goodman, Andrew L.; Henrissat, Bernard; Oozeer, Raish; Cools-Portier, Stéphanie; Gobert, Guillaume; Chervaux, Christian; Knights, Dan; Lozupone, Catherine A.; Knight, Rob; Duncan, Alexis E.; Bain, James R.; Muehlbauer, Michael J.; Newgard, Christopher B.; Heath, Andrew C.; Gordon, Jeffrey I.

    2012-01-01

    Understanding how the human gut microbiota and host are impacted by probiotic bacterial strains requires carefully controlled studies in humans and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks prior to, 7 weeks during, and 4 weeks following consumption of a commercially available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied prior to and after gavage with all five sequenced FMP strains. No significant changes in bacterial species composition or in the proportional representation of genes encoding known enzymes were observed in the feces of humans consuming the FMP. Only minimal changes in microbiota configuration were noted in mice following single or repeated gavage with the FMP consortium. However, RNA-Seq analysis of fecal samples and follow-up mass spectrometry of urinary metabolites disclosed that introducing the FMP strains into mice results in significant changes in expression of microbiome-encoded enzymes involved in numerous metabolic pathways, most prominently those related to carbohydrate metabolism. B. animalis subsp. lactis, the dominant persistent member of the FMP consortium in gnotobiotic mice, upregulates a locus in vivo that is involved in the catabolism of xylooligosaccharides, a class of glycans widely distributed in fruits, vegetables and other foods, underscoring the importance of these sugars to this bacterial species. The human fecal metatranscriptome exhibited significant

  16. The impact of a consortium of fermented milk strains on the gut microbiome of gnotobiotic mice and monozygotic twins.

    PubMed

    McNulty, Nathan P; Yatsunenko, Tanya; Hsiao, Ansel; Faith, Jeremiah J; Muegge, Brian D; Goodman, Andrew L; Henrissat, Bernard; Oozeer, Raish; Cools-Portier, Stéphanie; Gobert, Guillaume; Chervaux, Christian; Knights, Dan; Lozupone, Catherine A; Knight, Rob; Duncan, Alexis E; Bain, James R; Muehlbauer, Michael J; Newgard, Christopher B; Heath, Andrew C; Gordon, Jeffrey I

    2011-10-26

    Understanding how the human gut microbiota and host are affected by probiotic bacterial strains requires carefully controlled studies in humans and in mouse models of the gut ecosystem where potentially confounding variables that are difficult to control in humans can be constrained. Therefore, we characterized the fecal microbiomes and metatranscriptomes of adult female monozygotic twin pairs through repeated sampling 4 weeks before, 7 weeks during, and 4 weeks after consumption of a commercially available fermented milk product (FMP) containing a consortium of Bifidobacterium animalis subsp. lactis, two strains of Lactobacillus delbrueckii subsp. bulgaricus, Lactococcus lactis subsp. cremoris, and Streptococcus thermophilus. In addition, gnotobiotic mice harboring a 15-species model human gut microbiota whose genomes contain 58,399 known or predicted protein-coding genes were studied before and after gavage with all five sequenced FMP strains. No significant changes in bacterial species composition or in the proportional representation of genes encoding known enzymes were observed in the feces of humans consuming the FMP. Only minimal changes in microbiota configuration were noted in mice after single or repeated gavage with the FMP consortium. However, RNA-Seq analysis of fecal samples and follow-up mass spectrometry of urinary metabolites disclosed that introducing the FMP strains into mice results in significant changes in expression of microbiome-encoded enzymes involved in numerous metabolic pathways, most prominently those related to carbohydrate metabolism. B. animalis subsp. lactis, the dominant persistent member of the FMP consortium in gnotobiotic mice, up-regulates a locus in vivo that is involved in the catabolism of xylooligosaccharides, a class of glycans widely distributed in fruits, vegetables, and other foods, underscoring the importance of these sugars to this bacterial species. The human fecal metatranscriptome exhibited significant changes

  17. Simultaneous subependymomas in monozygotic female twins: further evidence for a common genetic or developmental disorder background.

    PubMed

    Noell, Susan; Beschorner, Rudi; Bisdas, Sotirios; Beyer, Ulrike; Weber, Ruthild G; Fallier-Becker, Petra; Ritz, Rainer

    2014-09-01

    In this paper, a rare case of subependymoma of the fourth ventricle in identical female twins is reported. Magnetic resonance imaging and CT showed nearly identical locations of the tumors in the fourth ventricle and similar growth patterns of the tumors in both sisters. Likewise, postoperative histopathological analysis of both tumors revealed the typical histological appearance of subependymomas. Subependymoma is a rare, low-grade glioma of the CNS, slowly growing and usually asymptomatic. If symptomatic, a subependymoma can in some cases lead to sudden death caused by pressure on the brainstem or decompensated secondary hydrocephalus. This case demonstrates the importance of detecting tumors early and thereby preventing symptoms arising from increasing intracranial pressure, and optimizing therapy options. PMID:24655099

  18. Differential Parenting and Risk for Psychopathology: A Monozygotic Twin Difference Approach

    PubMed Central

    Long, E.C.; Aggen, S. H.; Gardner, C.; Kendler, K. S.

    2015-01-01

    Purpose Consistent and non-specific associations have been found between parenting style and major depression, anxiety disorders, and externalizing behavior. Although often considered part of twins’ shared environment, parenting can also be conceptualized as non-shared environment. Non-shared environmental influences have important effects on development but are difficult to test and sort out because of the possible confounding effects of gene-environment interactions and evocative gene-environment correlations. The MZ differences approach is one way to analytically investigate non-shared environment. Methods The aim of the present study is to use the MZ differences approach to investigate the relationship between differential parenting among 1,303 twin pairs (mean age 36.69 +/− 8.56) and differences in total symptom counts of major depression (MD), generalized anxiety disorder (GAD), conduct disorder (CD), and anti-social behavior (ASB) during adulthood. Results Although effect sizes tended to be small, a number of results were significantly different from zero. Perceived differences in parental coldness was positively associated with internalizing disorders. Differences in protectiveness were negatively associated with MD, GAD, and ASB. Differences in authoritarianism were positively associated with MD and CD, but negatively associated with ASB. Conclusions Perceived differences in parenting style are associated with differences in MD, GAD, CD, and ASB outcomes in a sample of MZ twins. Despite the lack of a basis for making causal inferences about parenting style and psychopathology, these results are suggestive of such a relationship and show that non-shared environmental influence of parenting does in some cases significantly predict adult psychopathology. PMID:25940788

  19. Whole-exome sequencing in a family with a monozygotic twin pair concordant for autism spectrum disorder and a follow-up study.

    PubMed

    Egawa, Jun; Watanabe, Yuichiro; Sugimoto, Atsunori; Nunokawa, Ayako; Shibuya, Masako; Igeta, Hirofumi; Inoue, Emiko; Hoya, Satoshi; Orime, Naoki; Hayashi, Taketsugu; Sugiyama, Toshiro; Someya, Toshiyuki

    2015-09-30

    Two truncating variations (WDR90 V1125fs and EFCAB5 L1210fs), identified by whole-exome sequencing in a family with a monozygotic twin pair concordant for autism spectrum disorder (ASD), were not detected in 257 ASD patients, 677 schizophrenia patients or 667 controls in a follow-up study. Thus, these variations were exclusively identified in the family, suggesting that rare truncating variations may have a role in the genetic etiology of ASD, at least in a subset of ASD patients. PMID:26189338

  20. Placenta share discordance and umbilical artery Doppler change after antenatal betamethasone administration in monochorionic twins with selective intrauterine growth restriction: is there a link?

    PubMed

    Chang, Yao-Lung; Chang, Shuenn-Dyh; Chao, An-Shine; Hsieh, Peter C C; Wang, Chao-Nin; Wang, Tzu-Hao

    2012-10-01

    This study was designed to evaluate the degree of placenta share discordance in relation to the betamethasone-induced return of positive end-diastolic flow in monochorionic twin pregnancies with selective intrauterine growth restriction (sIUGR) and abnormal umbilical artery Doppler. Monochorionic twins with sIUGR was defined as one twin having an estimated fetal weight below the 10th percentile combined with an estimated fetal weight discordance >25%. The umbilical artery Doppler directly prior to (D0) and 24 hours (D1) and 48 hours (D2) after the first dose of betamethasone administration was recorded. The estimated individual placental weight in monochorionic twins was obtained by cutting the placenta along the vascular equator into two territories; the placenta share discordance was calculated as [(estimated individual placental weight of appropriated for gestational age twin- estimated individual placental weight of growth restricted twin)/estimated individual placental weight of appropriated for gestational age twin] × 100%. Six (23.1%) of the 26 included cases achieved betamethasone-induced return of positive umbilical artery end-diastolic flow. The difference of placenta share discordance and birth weight discordance were not significantly different between twins with and without betamethasone-induced return of positive umbilical artery end-diastolic flow. Thus, according to our study results, it was proposed that although the placenta share discordance correlated with the abnormal umbilical artery Doppler in the IUGR fetus in monochorionic twin, the betamethasone-induced return of positive umbilical artery end-diastolic flow, however, did not reveal the similar relationship with the severity of placenta share discordance.

  1. Multimodal brain imaging in autism spectrum disorder and the promise of twin research.

    PubMed

    Mevel, Katell; Fransson, Peter; Bölte, Sven

    2015-07-01

    Current evidence suggests the phenotype of autism spectrum disorder to be driven by a complex interaction of genetic and environmental factors impacting onto brain maturation, synaptic function, and cortical networks. However, findings are heterogeneous, and the exact neurobiological pathways of autism spectrum disorder still remain poorly understood. The co-twin control or twin-difference design is a potentially powerful tool to disentangle causal genetic and environmental contributions on neurodevelopment in autism spectrum disorder. To this end, monozygotic twins discordant for this condition provide unique means for the maximum control of potentially confounding factors. Unfortunately, only few studies of a rather narrow scope, and limited sample size, have been conducted. In an attempt to highlight the great potential of combining the brain connectome approach with monozygotic twin design, we first give an overview of the existing neurobiological evidence for autism spectrum disorder and its cognitive correlates. Then, a special focus is made onto the brain imaging findings reported within populations of monozygotic twins phenotypically discordant for autism spectrum disorder. Finally, we introduce the brain connectome model and describe an ongoing project using this approach among the largest cohort of monozygotic twins discordant for autism spectrum disorder ever recruited.

  2. Case report: cytokine and CD4+ T-cell profiles of monozygotic twins with autism and divergent comorbidities and drug treatment.

    PubMed

    Magid-Bernstein, Jessica; Mahajan, Kedar; Lincoln, John; Ming, Xue; Rohowsky-Kochan, Christine

    2015-03-01

    Autism spectrum disorders are neurodevelopmental disorders that are thought to be caused by a gene-by-environment interaction and in which various immune alterations are reported. We investigate CD4(+) T-cell cytokine profiles and subpopulations in 19-year-old monozygotic twins with autism and different comorbidities. CD4(+) T cells from the twin with epilepsy produce more interferon-gamma, less interleukin-17, and have an increased interferon-γ/interleukin-4 ratio. CD4(+) T cells from the twin with multiple sclerosis exhibit a cytokine profile similar to an age and gender-matched control and a higher percentage of T regulatory (Treg) cells. The twins' mother's T cells produce very high levels of both interleukin-17 and interferon-γ. Cytokine and CD4(+) T-cell abnormalities in the twins could contribute to or be a result of the manifestation of their divergent comorbidities. A proinflammatory, autoimmune-polarized cytokine profile is observed in this unique family with autism.

  3. Cervical pachymeningeal hypertrophy as the initial and cardinal manifestation of mucopolysaccharidosis type I in monozygotic twins with a novel mutation in the alpha-L-iduronidase gene.

    PubMed

    Furukawa, Yutaka; Hamaguchi, Ayumi; Nozaki, Ichiro; Iizuka, Takashi; Sasagawa, Takeshi; Shima, Yosuke; Demura, Satoru; Murakami, Hideki; Kawahara, Norio; Okuyama, Torayuki; Iwasa, Kazuo; Yamada, Masahito

    2011-03-15

    We describe a pair of monozygotic twins with an attenuated form of mucopolysaccharidosis type I (MPS-I). At age 24, they both developed cervical myelopathy as a cardinal manifestation. They each also had mild valve abnormalities and both inguinal and umbilical hernia, however, other characteristic features of MPS-I were absent or very mild. Magnetic resonance imaging revealed the cervical cord compressed by pachymeningeal hypertrophy. Surgery with dural plasty and laminoplasty resulted in decompression of the cervical cord with clinical improvement, revealing marked thickening of the dura mater. Both patients showed a marked decrease of alpha-L-iduronidase (IDUA) activity with c.252insC (p.P55fsX62; known) and c.1209C>A (p.T374N; novel) mutations of the IDUA gene (IDUA). Patients with MPS-I have been reported to present with various clinical phenotypes and severities even if they have identical mutations of IDUA. The quite similar, unique phenotype in monozygotic twins suggests that not only IDUA mutation but also other genetic factors than IDUA markedly influence the clinical manifestations of MPS-I. PMID:21176924

  4. Frequent Extreme Cold Exposure and Brown Fat and Cold-Induced Thermogenesis: A Study in a Monozygotic Twin

    PubMed Central

    Vosselman, Maarten J.; Vijgen, Guy H. E. J.; Kingma, Boris R. M.; Brans, Boudewijn; van Marken Lichtenbelt, Wouter D.

    2014-01-01

    Introduction Mild cold acclimation is known to increase brown adipose tissue (BAT) activity and cold-induced thermogenesis (CIT) in humans. We here tested the effect of a lifestyle with frequent exposure to extreme cold on BAT and CIT in a Dutch man known as ‘the Iceman’, who has multiple world records in withstanding extreme cold challenges. Furthermore, his monozygotic twin brother who has a ‘normal’ sedentary lifestyle without extreme cold exposures was measured. Methods The Iceman (subject A) and his brother (subject B) were studied during mild cold (13°C) and thermoneutral conditions (31°C). Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect calorimetry. In addition, body temperatures, cardiovascular parameters, skin perfusion, and thermal sensation and comfort were measured. Finally, we determined polymorphisms for uncoupling protein-1 and β3-adrenergic receptor. Results Subjects had comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal), within the range previously observed in young adult men. They were genotyped with the polymorphism for uncoupling protein-1 (G/G). CIT was relatively high (A: 40.1% and B: 41.9%), but unlike during our previous cold exposure tests in young adult men, here both subjects practiced a g-Tummo like breathing technique, which involves vigorous respiratory muscle activity. This was confirmed by high [18F]FDG-uptake in respiratory muscle. Conclusion No significant differences were found between the two subjects, indicating that a lifestyle with frequent exposures to extreme cold does not seem to affect BAT activity and CIT. In both subjects, BAT was not higher compared to earlier observations, whereas CIT was very high, suggesting that g-Tummo like breathing during cold exposure may cause additional heat production by vigorous isometric respiratory muscle contraction. The results must be interpreted with caution given the low

  5. Nonshared environmental mediation of the association between deviant peer affiliation and adolescent externalizing behaviors over time: results from a cross-lagged monozygotic twin differences design.

    PubMed

    Burt, S Alexandra; McGue, Matt; Iacono, William G

    2009-11-01

    It has been argued that peers are the most important agent of adolescent socialization and, more specifically, that this socialization process occurs at the child-specific (or nonshared environmental) level (J. R. Harris, 1998; R. Plomin & Asbury, 2005). The authors sought to empirically evaluate this nonshared environmental peer influence hypothesis by examining the association between externalizing behaviors and deviant peer affiliation in a sample of 454 pairs of monozygotic (genetically identical) twins, assessed at ages 14 and 17, within a cross-lagged twin differences design. Results argued against a causal nonshared environmental influence of peer affiliation on the development of externalizing behaviors and in favor of nonshared environmental "selection." In particular, the twin with more externalizing behaviors at age 14 reported increased deviant peer affiliation relative to his or her co-twin 3 years later, regardless of his or her genetic predispositions toward externalizing behavior. Such findings suggest that adolescents with higher levels of externalizing behaviors select or shape (either intentionally or inadvertently) subsequent environmental experiences to involve increased affiliation with deviant peers. Implications are discussed.

  6. Tests of a Direct Effect of Childhood Abuse on Adult Borderline Personality Disorder Traits: A Longitudinal Discordant Twin Design

    PubMed Central

    Bornovalova, Marina A.; Huibregtse, Brooke M.; Hicks, Brian M.; Keyes, Margaret; McGue, Matt; Iacono, William

    2012-01-01

    We used a longitudinal twin design to examine the causal association between sexual, emotional, and physical abuse in childhood (before age 18) and borderline personality disorder (BPD) traits at age 24 using a discordant twin design and biometric modeling. Additionally, we examined the mediating and moderating effects of symptoms of childhood externalizing and internalizing disorders on the link between childhood abuse and BPD traits. Although childhood abuse, BPD traits, and internalizing and externalizing symptoms were all correlated, the discordant twin analyses and biometric modeling showed little to no evidence that consistent with a causal effect of childhood abuse on BPD traits. Instead, our results indicate that the association between childhood abuse and BPD traits stems from common genetic influences that, in some cases, also overlap with internalizing and externalizing disorders. These findings are inconsistent with the widely held assumption that childhood abuse causes BPD, and suggests that BPD traits in adulthood are better accounted for by heritable vulnerabilities to internalizing and externalizing disorders. PMID:22686871

  7. Methylation matters? Decreased methylation status of genomic DNA in the blood of schizophrenic twins.

    PubMed

    Bönsch, Dominikus; Wunschel, Michael; Lenz, Bernd; Janssen, Gesa; Weisbrod, Matthias; Sauer, Heinrich

    2012-08-15

    Studies of schizophrenia inheritance in identical twins show a concordance of about 50%, which supports an epigenetic model. In our present study we investigated methylation of genomic DNA and promoter methylation of Reelin and SOX10 genes in peripheral blood of twins suffering from schizophrenia. Global DNA methylation was reduced (52.3%) in schizophrenic twins if compared with healthy control twins (65.7%). The reduced methylation was significant in males only. We also found a similar hypomethylation in the non-affected twins of discordant pairs and a mixed group of psychiatric controls. In discordant twins there was a relative hypermethylation of the SOX10 promoter. Within-pair-difference of methylation of Reelin promoter was significantly lower in monozygotic twins than in dizygotic twins. PMID:23102571

  8. Clones in the classroom: a daily diary study of the nonshared environmental relationship between monozygotic twin differences in school experience and achievement.

    PubMed

    Asbury, Kathryn; Almeida, David; Hibel, Jacob; Harlaar, Nicole; Plomin, Robert

    2008-12-01

    Do genetically identical children experience the same classroom differently? Are nonshared classroom experiences associated with differences in achievement? We designed a telephone diary measure which we administered every school day for 2 weeks to 122 10-year-olds in 61 monozygotic (MZ) twin pairs. Each pair shared genes, a classroom, peers and a teacher. We found that MZ twins did experience their classrooms differently (rMZ < 0.65 for all measures of classroom experience). Furthermore, MZ differences in peer problems were significantly associated with MZ differences in Mathematics achievement (ES = 8%); differences in positivity about school were significantly associated with differences in Mathematics (ES = 15%) and Science (ES = 8%) achievement; and differences in 'flow' in Science lessons were associated with differences in Science achievement (ES = 12%). In a multiple regression analysis, MZ differences in positivity about school significantly predicted MZ differences in Mathematics achievement (R2 = 0.16, p < .01) and MZ differences in 'flow' in Science significantly predicted MZ differences in Science achievement (R2 = 0.10, p < .05). These results indicate that MZ twins experience the classroom differently and that differences in their experience are associated with differences in their achievement. PMID:19016614

  9. Nature and nurture: a case of transcending haematological pre-malignancies in a pair of monozygotic twins adding possible clues on the pathogenesis of B-cell proliferations.

    PubMed

    Hansen, Marcus C; Nyvold, Charlotte G; Roug, Anne S; Kjeldsen, Eigil; Villesen, Palle; Nederby, Line; Hokland, Peter

    2015-05-01

    We describe a comprehensive molecular analysis of a pair of monozygotic twins, who came to our attention when one experienced amaurosis fugax and was diagnosed with JAK2+ polycythaemia vera. He (Twin A) was also found to have an asymptomatic B-cell chronic lymphocytic leukaemia (B-CLL). Although JAK2-, Twin B was subsequently shown to have a benign monoclonal B-cell lymphocytosis (MBL). Flow cytometric and molecular analyses of the B-cell compartments revealed different immunoglobulin light and heavy chain usage in each twin. We hypothesized that whole exome sequencing could help delineating the pattern of germline B-cell disorder susceptibility and reveal somatic mutations potentially contributing to the differential patterns of pre-malignancy. Comparing bone marrow cells and T cells and employing in-house engineered integrative analysis, we found aberrations in Twin A consistent with a myeloid neoplasm, i.e. in TET2, RUNX1, PLCB1 and ELF4. Employing the method for detecting high-ranking variants by extensive annotation and relevance scoring, we also identified shared germline variants in genes of proteins interacting with B-cell receptor signalling mediators and the WNT-pathway, including IRF8, PTPRO, BCL9L, SIT1 and SIRPB1, all with possible implications in B-cell proliferation. Similar patterns of IGHV-gene usage to those demonstrated here have been observed in inherited acute lymphoblastic leukaemia. Collectively, these findings may help in facilitating identification of putative master gene(s) involved in B-cell proliferations in general and MBL and B-CLL in particular. PMID:25752595

  10. Total and Trimester-Specific Gestational Weight Gain and Offspring Birth and Early Childhood Weight: A Prospective Cohort Study on Monozygotic Twin Mothers and Their Offspring.

    PubMed

    Scheers Andersson, Elina; Silventoinen, Karri; Tynelius, Per; Nohr, Ellen A; Sørensen, Thorkild I A; Rasmussen, Finn

    2016-08-01

    Gestational weight gain (GWG) has in numerous studies been associated with offspring birth weight (BW) and childhood weight. However, these associations might be explained by genetic confounding as offspring inherit their mother's genetic potential to gain weight. Furthermore, little is known about whether particular periods of pregnancy could influence offspring body weight differently. We therefore aimed to explore total and trimester-specific effects of GWG in monozygotic (MZ) twin mother-pairs on their offspring's BW, weight at 1 year and body mass index (BMI) at 5 and 10 years. MZ twin mothers born 1962-1975 were identified in national Swedish registers, and data on exposure and outcome variables was collected from medical records. We analyzed associations within and between twin pairs. We had complete data on the mothers' GWG and offspring BW for 82 pairs. The results indicated that total, and possibly also second and third trimester GWG were associated with offspring BW within the twin pairs in the fully adjusted model (β = 0.08 z-score units, 95% CI: 0.001, 0.17; β = 1.32 z-score units, 95% CI: -0.29, 2.95; and β = 1.02 z-score units, 95% CI: -0.50, 2.54, respectively). Our findings, although statistically weak, suggested no associations between GWG and offspring weight or BMI during infancy or childhood. Our study suggests that total, and possibly also second and third trimester, GWG are associated with offspring BW when taking shared genetic and environmental factors within twin pairs into account. Larger family-based studies with long follow-up are needed to confirm our findings. PMID:27161254

  11. Nature and nurture: a case of transcending haematological pre-malignancies in a pair of monozygotic twins adding possible clues on the pathogenesis of B-cell proliferations.

    PubMed

    Hansen, Marcus C; Nyvold, Charlotte G; Roug, Anne S; Kjeldsen, Eigil; Villesen, Palle; Nederby, Line; Hokland, Peter

    2015-05-01

    We describe a comprehensive molecular analysis of a pair of monozygotic twins, who came to our attention when one experienced amaurosis fugax and was diagnosed with JAK2+ polycythaemia vera. He (Twin A) was also found to have an asymptomatic B-cell chronic lymphocytic leukaemia (B-CLL). Although JAK2-, Twin B was subsequently shown to have a benign monoclonal B-cell lymphocytosis (MBL). Flow cytometric and molecular analyses of the B-cell compartments revealed different immunoglobulin light and heavy chain usage in each twin. We hypothesized that whole exome sequencing could help delineating the pattern of germline B-cell disorder susceptibility and reveal somatic mutations potentially contributing to the differential patterns of pre-malignancy. Comparing bone marrow cells and T cells and employing in-house engineered integrative analysis, we found aberrations in Twin A consistent with a myeloid neoplasm, i.e. in TET2, RUNX1, PLCB1 and ELF4. Employing the method for detecting high-ranking variants by extensive annotation and relevance scoring, we also identified shared germline variants in genes of proteins interacting with B-cell receptor signalling mediators and the WNT-pathway, including IRF8, PTPRO, BCL9L, SIT1 and SIRPB1, all with possible implications in B-cell proliferation. Similar patterns of IGHV-gene usage to those demonstrated here have been observed in inherited acute lymphoblastic leukaemia. Collectively, these findings may help in facilitating identification of putative master gene(s) involved in B-cell proliferations in general and MBL and B-CLL in particular.

  12. Motives for and barriers to physical activity in twin pairs discordant for leisure time physical activity for 30 years.

    PubMed

    Aaltonen, S; Leskinen, T; Morris, T; Alen, M; Kaprio, J; Liukkonen, J; Kujala, U

    2012-02-01

    Long-term persistent physical activity is important in the prevention of chronic diseases, but a large number of people do not participate in physical activity to obtain health benefits. The purpose of this study was to examine the motives and perceived barriers to long-term engagement in leisure time physical activity. Same-sex twin pairs (N=16, mean age 60) discordant for physical activity over 30 years were identified from the Finnish Twin Cohort. We evaluated participants' physical activity motivation with the 73-item Recreational Exercise Motivation Measure and assessed barriers to physical activity with a 25-item questionnaire. The characteristics of physical activity motivation and perceived barriers between the active and inactive co-twins were analysed using paired tests. Motives related to the sub-dimensions of enjoyment and physical fitness and psychological state were the most important reasons for participation in physical activity among all the twin individuals analysed. The sub-dimensions mastery (p=0.018, Cohen's d=0.76), physical fitness (p=0.029, Cohen's d=0.69), and psychological state (p=0.039, Cohen's d=0.65) differed significantly between active and inactive co-twins. More than half of the participants reported no reasons for not being physically active. If reasons existed, participation in physical activity was deterred mostly by pain and various health problems. This study found no differences in perceived barriers between active and inactive co-twins. We conclude from our results that the main factors promoting persistent leisure time physical activity were participants' wish to improve or maintain their physical skills or techniques, a feeling that exercise would improve their mental and physical health and that they found the activity enjoyable. This study helps us understand the importance of the role of motives and the minor role of perceived barriers for engagement in persistent physical activity. PMID:22318531

  13. Identical de novo mutation at the D4F104S1 locus in monozygotic male twins affected by facioscapulohumeral muscular dystrophy (FSHD) with different clinical expression.

    PubMed Central

    Tupler, R; Barbierato, L; Memmi, M; Sewry, C A; De Grandis, D; Maraschio, P; Tiepolo, L; Ferlini, A

    1998-01-01

    Facioscapulohumeral muscular dystrophy (FSHD) is a progressive hereditary neuromuscular disorder, transmitted in an autosomal dominant fashion. Its clinical expression is highly variable, ranging from almost asymptomatic subjects to wheelchair dependent patients. The molecular defect has been linked to chromosome 4q35 markers and has been related to deletions of tandemly repeated sequences located in the subtelomeric region detected by probe p13E-11 (D4F104S1). We describe a pair of monozygotic male twins affected by FSHD, carrying an identical de novo p13E-11 EcoRI fragment of paternal origin and showing great variability in the clinical expression of the disease, one being almost asymptomatic and the other severely affected. Their medical history was the same, with the exception of an anti-rabies vaccination performed at the age of 5 in the more severely affected twin. We hypothesise that the vaccination might have triggered an inflammatory immune reaction contributing to the more severe phenotype. Images PMID:9733041

  14. Gene Expression Profiles from Disease Discordant Twins Suggest Shared Antiviral Pathways and Viral Exposures among Multiple Systemic Autoimmune Diseases.

    PubMed

    Gan, Lu; O'Hanlon, Terrance P; Lai, Zhennan; Fannin, Rick; Weller, Melodie L; Rider, Lisa G; Chiorini, John A; Miller, Frederick W

    2015-01-01

    Viral agents are of interest as possible autoimmune triggers due to prior reported associations and widely studied molecular mechanisms of antiviral immune responses in autoimmunity. Here we examined new viral candidates for the initiation and/or promotion of systemic autoimmune diseases (SAID), as well as possible related signaling pathways shared in the pathogenesis of those disorders. RNA isolated from peripheral blood samples from 33 twins discordant for SAID and 33 matched, unrelated healthy controls was analyzed using a custom viral-human gene microarray. Paired comparisons were made among three study groups-probands with SAID, their unaffected twins, and matched, unrelated healthy controls-using statistical and molecular pathway analyses. Probands and unaffected twins differed significantly in the expression of 537 human genes, and 107 of those were associated with viral infections. These 537 differentially expressed human genes participate in overlapping networks of several canonical, biologic pathways relating to antiviral responses and inflammation. Moreover, certain viral genes were expressed at higher levels in probands compared to either unaffected twins or unrelated, healthy controls. Interestingly, viral gene expression levels in unaffected twins appeared intermediate between those of probands and the matched, unrelated healthy controls. Of the viruses with overexpressed viral genes, herpes simplex virus-2 (HSV-2) was the only human viral pathogen identified using four distinct oligonucleotide probes corresponding to three HSV-2 genes associated with different stages of viral infection. Although the effects from immunosuppressive therapy on viral gene expression remain unclear, this exploratory study suggests a new approach to evaluate shared viral agents and antiviral immune responses that may be involved in the development of SAID.

  15. Heritable breast cancer in twins

    PubMed Central

    Mack, T M; Hamilton, A S; Press, M F; Diep, A; Rappaport, E B

    2002-01-01

    Known major mutations such as BRCA1/2 and TP53 only cause a small proportion of heritable breast cancers. Co-dominant genes of lower penetrance that regulate hormones have been thought responsible for most others. Incident breast cancer cases in the identical (monozygotic) twins of representative cases reflect the entire range of pertinent alleles, whether acting singly or in combination. Having reported the rate in twins and other relatives of cases to be high and nearly constant over age, we now examine the descriptive and histological characteristics of the concordant and discordant breast cancers occurring in 2310 affected pairs of monozygotic and fraternal (dizygotic) twins in relation to conventional expectations and hypotheses. Like other first-degree relatives, dizygotic co-twins of breast cancer cases are at higher than usual risk (standardised incidence ratio (SIR)=1.7, CI=1.1–2.6), but the additional cases among monozygotic co-twins of cases are much more numerous, both before and after menopause (SIR=4.4, CI=3.6–5.6), than the 100% genetic identity would predict. Monozygotic co-twin diagnoses following early proband cancers also occur more rapidly than expected (within 5 years, SIR=20.0, CI=7.5–53.3). Cases in concordant pairs represent heritable disease and are significantly more likely to be oestrogen receptor-positive than those of comparable age from discordant pairs. The increase in risk to the monozygotic co-twins of cases cannot be attributed to the common environment, to factors that cumulate with age, or to any aggregate of single autosomal dominant mutations. The genotype more plausibly consists of multiple co-existing susceptibility alleles acting through heightened susceptibility to hormones and/or defective tumour suppression. The resultant class of disease accounts for a larger proportion of all breast cancers than previously thought, with a rather high overall penetrance. Some of the biological characteristics differ from those of

  16. The precise timing of embryo splitting for monozygotic dichorionic diamniotic twins: when does embryo splitting for monozygotic dichorionic diamniotic twins occur? Evidence for splitting at the morula/blastocyst stage from studies of in vitro fertilization.

    PubMed

    Kyono, Koichi

    2013-08-01

    There is a long-held credo, as illustrated in Langman's Medical Embryology (11th ed., Sadler, 2010), that dichorionic diamniotic (DD) twins develop after embryo splitting in the early stages of embryonic development. However, from our clinical experiences of the examination of data from single-embryo transfers in 16 fertility clinics in Japan and from various reports, the majority of occurrences of DD twins have been found in the blastocyst stages.

  17. Behavioral versus genetic determination of lipoproteins andidentical twins discordant for exercise

    SciTech Connect

    Williams, Paul T.; Blanche, Patricia J.; Krauss, Ronald M.

    2004-06-01

    Lipoprotein and weight differences between vigorously active and sedentary MZ twins are used to: (1) estimate the effects of training while controlling for genotype; (2) estimate genetic concordance in the presence of divergent lifestyles.

  18. Premature twins of a mother with Graves' disease with discordant thyroid function: a case report.

    PubMed

    O'Connor, M J; Paget-Brown, A O; Clarke, W L

    2007-06-01

    Thyroid dysfunction is recognized in the newborns of mothers affected by Graves' disease during pregnancy. We describe the development of concurrent hyperthyroidism and hypothyroidism in the twin infants of a mother with Graves' disease diagnosed during pregnancy.

  19. Person-Specific Non-shared Environmental Influences in Intra-individual Variability: A Preliminary Case of Daily School Feelings in Monozygotic Twins.

    PubMed

    Zheng, Yao; Molenaar, Peter C M; Arden, Rosalind; Asbury, Kathryn; Almeida, David M

    2016-09-01

    Most behavioural genetic studies focus on genetic and environmental influences on inter-individual phenotypic differences at the population level. The growing collection of intensive longitudinal data in social and behavioural science offers a unique opportunity to examine genetic and environmental influences on intra-individual phenotypic variability at the individual level. The current study introduces a novel idiographic approach and one novel method to investigate genetic and environmental influences on intra-individual variability by a simple empirical demonstration. Person-specific non-shared environmental influences on intra-individual variability of daily school feelings were estimated using time series data from twenty-one pairs of monozygotic twins (age = 10 years, 16 female pairs) over two consecutive weeks. Results showed substantial inter-individual heterogeneity in person-specific non-shared environmental influences. The current study represents a first step in investigating environmental influences on intra-individual variability with an idiographic approach, and provides implications for future behavioural genetic studies to examine developmental processes from a microscopic angle.

  20. Person-Specific Non-shared Environmental Influences in Intra-individual Variability: A Preliminary Case of Daily School Feelings in Monozygotic Twins.

    PubMed

    Zheng, Yao; Molenaar, Peter C M; Arden, Rosalind; Asbury, Kathryn; Almeida, David M

    2016-09-01

    Most behavioural genetic studies focus on genetic and environmental influences on inter-individual phenotypic differences at the population level. The growing collection of intensive longitudinal data in social and behavioural science offers a unique opportunity to examine genetic and environmental influences on intra-individual phenotypic variability at the individual level. The current study introduces a novel idiographic approach and one novel method to investigate genetic and environmental influences on intra-individual variability by a simple empirical demonstration. Person-specific non-shared environmental influences on intra-individual variability of daily school feelings were estimated using time series data from twenty-one pairs of monozygotic twins (age = 10 years, 16 female pairs) over two consecutive weeks. Results showed substantial inter-individual heterogeneity in person-specific non-shared environmental influences. The current study represents a first step in investigating environmental influences on intra-individual variability with an idiographic approach, and provides implications for future behavioural genetic studies to examine developmental processes from a microscopic angle. PMID:27040685

  1. Clonal origins of ETV6-RUNX1⁺ acute lymphoblastic leukemia: studies in monozygotic twins.

    PubMed

    Alpar, D; Wren, D; Ermini, L; Mansur, M B; van Delft, F W; Bateman, C M; Titley, I; Kearney, L; Szczepanski, T; Gonzalez, D; Ford, A M; Potter, N E; Greaves, M

    2015-04-01

    Studies on twins with concordant acute lymphoblastic leukemia (ALL) have revealed that ETV6-RUNX1 gene fusion is a common, prenatal genetic event with other driver aberrations occurring subclonally and probably postnatally. The fetal cell type that is transformed by ETV6-RUNX1 is not identified by such studies or by the analysis of early B-cell lineage phenotype of derived progeny. Ongoing, clonal immunoglobulin (IG) and cross-lineage T-cell receptor (TCR) gene rearrangements are features of B-cell precursor leukemia and commence at the pro-B-cell stage of normal B-cell lineage development. We reasoned that shared clonal rearrangements of IG or TCR genes by concordant ALL in twins would be informative about the fetal cell type in which clonal advantage is elicited by ETV6-RUNX1. Five pairs of twins were analyzed for all varieties of IG and TCR gene rearrangements. All pairs showed identical incomplete or complete variable-diversity-joining junctions coupled with substantial, subclonal and divergent rearrangements. This pattern was endorsed by single-cell genetic scrutiny in one twin pair. Our data suggest that the pre-leukemic initiating function of ETV6-RUNX1 fusion is associated with clonal expansion early in the fetal B-cell lineage. PMID:25388957

  2. Developmental timing of mutations revealed by whole-genome sequencing of twins with acute lymphoblastic leukemia.

    PubMed

    Ma, Yussanne; Dobbins, Sara E; Sherborne, Amy L; Chubb, Daniel; Galbiati, Marta; Cazzaniga, Giovanni; Micalizzi, Concetta; Tearle, Rick; Lloyd, Amy L; Hain, Richard; Greaves, Mel; Houlston, Richard S

    2013-04-30

    Acute lymphoblastic leukemia (ALL) is the major pediatric cancer. At diagnosis, the developmental timing of mutations contributing critically to clonal diversification and selection can be buried in the leukemia's covert natural history. Concordance of ALL in monozygotic, monochorionic twins is a consequence of intraplacental spread of an initiated preleukemic clone. Studying monozygotic twins with ALL provides a unique means of uncovering the timeline of mutations contributing to clonal evolution, pre- and postnatally. We sequenced the whole genomes of leukemic cells from two twin pairs with ALL to comprehensively characterize acquired somatic mutations in ALL, elucidating the developmental timing of all genetic lesions. Shared, prenatal, coding-region single-nucleotide variants were limited to the putative initiating lesions. All other nonsynonymous single-nucleotide variants were distinct between tumors and, therefore, secondary and postnatal. These changes occurred in a background of noncoding mutational changes that were almost entirely discordant in twin pairs and likely passenger mutations acquired during leukemic cell proliferation. PMID:23569245

  3. The Epigenesis of Planum Temporale Asymmetry in Twins

    PubMed Central

    Eckert, Mark A.; Leonard, Christiana M.; Molloy, Elizabeth A.; Blumenthal, Jonathan; Zijdenbos, Alex; Giedd, Jay N.

    2009-01-01

    Variation in hemispheric asymmetry of the planum temporale (PT) has been related to verbal ability. The degree to which genetic and environmental factors mediate PT asymmetry is not known. This study examined the heritability for planar asymmetry in 12 dizygotic (DZ) and 27 monozygotic (MZ) male twin pairs who were between 6 and 16 years of age. There was weak but positive evidence for heritability of planar asymmetry. Co-twin similarity for planar asymmetry and Sylvian fissure morphology increased when excluding twins discordant for writing hand and when excluding twins exhibiting birth weight differences >20% from the analyses. Birth weight differences were also related to twin differences in total cerebral volume, but not central sulcus asymmetry. These results suggest that exogenous perinatal factors affect the epigenesis of planar asymmetry development. PMID:12050086

  4. Causal Inference and Observational Research: The Utility of Twins

    PubMed Central

    McGue, Matt; Osler, Merete; Christensen, Kaare

    2011-01-01

    Valid causal inference is central to progress in theoretical and applied psychology. Although the randomized experiment is widely considered the gold standard for determining whether a given exposure increases the likelihood of some specified outcome, experiments are not always feasible and in some cases can result in biased estimates of causal effects. Alternatively, standard observational approaches are limited by the possibility of confounding, reverse causation, and the nonrandom distribution of exposure (i.e., selection). We describe the counterfactual model of causation and apply it to the challenges of causal inference in observational research, with a particular focus on aging. We argue that the study of twin pairs discordant on exposure, and in particular discordant monozygotic twins, provides a useful analog to the idealized counterfactual design. A review of discordant-twin studies in aging reveals that they are consistent with, but do not unambiguously establish, a causal effect of lifestyle factors on important late-life outcomes. Nonetheless, the existing studies are few in number and have clear limitations that have not always been considered in interpreting their results. It is concluded that twin researchers could make greater use of the discordant-twin design as one approach to strengthen causal inferences in observational research. PMID:21593989

  5. Common immune-related exposures/conditions and risk of non-Hodgkin lymphoma: a case-control study of disease-discordant twin pairs.

    PubMed

    Wang, Jun; Mack, Thomas M; Hamilton, Ann S; Hwang, Amie E; Nathwani, Bharat N; Masood, Kamil; Buchanan, Laura H; Bernstein, Leslie; Deapen, Dennis M; Martínez-Maza, Otoniel; Cozen, Wendy

    2015-09-01

    We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors. PMID:26271116

  6. Common immune-related exposures/conditions and risk of non-Hodgkin lymphoma: a case-control study of disease-discordant twin pairs.

    PubMed

    Wang, Jun; Mack, Thomas M; Hamilton, Ann S; Hwang, Amie E; Nathwani, Bharat N; Masood, Kamil; Buchanan, Laura H; Bernstein, Leslie; Deapen, Dennis M; Martínez-Maza, Otoniel; Cozen, Wendy

    2015-09-01

    We evaluated the association between common immune system-altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%-97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors.

  7. Common Immune-Related Exposures/Conditions and Risk of Non-Hodgkin Lymphoma: A Case-Control Study of Disease-Discordant Twin Pairs

    PubMed Central

    Wang, Jun; Mack, Thomas M.; Hamilton, Ann S.; Hwang, Amie E.; Nathwani, Bharat N.; Masood, Kamil; Buchanan, Laura H.; Bernstein, Leslie; Deapen, Dennis M.; Martínez-Maza, Otoniel; Cozen, Wendy

    2015-01-01

    We evaluated the association between common immune system–altering experiences and non-Hodgkin lymphoma (NHL) risk using a case-control study of 162 like-sex twin pairs discordant for NHL, identified from the International Twin Study. Information on medical history and evidence of childhood exposure to microbes was obtained by questionnaire from 1998 to 2002. Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals. Intra-twin-pair agreement between twins on individual exposures was high (76%–97%). A negative association between NHL and seasonal hay fever (odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.10, 0.75) and certain allergies (OR = 0.29, 95% CI: 0.13, 0.68) was observed. The number of atopic diseases was negatively associated with NHL (P for trend = 0.0003). A history of infectious mononucleosis was negatively associated with NHL risk (OR = 0.35, 95% CI: 0.14, 0.90). NHL risk was associated with more frequent childhood exposure to microbes during early life (P for trend = 0.04). No differences in association by NHL subtype were observed, although statistical power for these comparisons was low. These observations support the hypothesis that immune-related exposures, especially atopy, are associated with decreased NHL risk. Use of the within-twin-pair study design mitigates confounding by genome, family structure, and unmeasured characteristics of early childhood factors. PMID:26271116

  8. The value of twins in epigenetic epidemiology.

    PubMed

    Bell, Jordana T; Saffery, Richard

    2012-02-01

    During past decades, twin studies have played an important role in genetic epidemiology studies of complex traits. The strength of twin studies lies in the ability to disentangle genetic and environmental factors that contribute to a phenotype, by comparing genetically identical monozygotic twins to dizygotic twins, who share on average 50% of genetic variants. Twin studies now offer the opportunity to study epigenetic variation across the genome with two aims. First, twin studies can improve our understanding of the factors regulating epigenetic variability by assessing the heritability of epigenetic variants. Secondly, the use of twins in epigenetic research is increasingly recognized as an important approach to help unravel the complexities associated with human development and disease. The strategic use of identical twins discordant for complex disease has revealed the importance of linking epigenetic disruption to the disease-associated risk in humans. Lastly, we also discuss the possibility that epigenetic effects on disease may in part explain some of the missing heritability in genome-wide association studies. The study of human epigenetic factors in twins can inform the role of genetics, as well as in utero and postnatal environments to the establishment, maintenance and functional consequences of human epigenome variation. PMID:22253312

  9. DNA methylation profiles in type 1 diabetes twins point to strong epigenetic effects on etiology.

    PubMed

    Stefan, Mihaela; Zhang, Weijia; Concepcion, Erlinda; Yi, Zhengzi; Tomer, Yaron

    2014-05-01

    Type 1 diabetes (T1D) shows ∼40% concordance rate in monozygotic twins (MZ) suggesting a role for environmental factors and/or epigenetic modifications in the etiology of the disease. The aim of our study was to dissect the contribution of epigenetic factors, particularly, DNA methylation (DNAm), to the incomplete penetrance of T1D. We performed DNAm profiling in lymphocyte cell lines from 3 monozygotic (MZ) twin pairs discordant for T1D and 6 MZ twin pairs concordant for the disease using HumanMethylation27 BeadChip. This assay assesses the methylation state of 27,578 CpG sites, mostly located within proximal promoter regions. We identified 88 CpG sites displaying significant methylation changes in all T1D-discordant MZ twin pairs. Functional annotation of the genes with distinct CpG methylation profiles in T1D samples showed differential DNAm of immune response and defense response pathways between affected and unaffected twins. Integration of DNAm data with GWAS data mapped several known T1D associated genes, HLA, INS, IL-2RB, CD226, which showed significant differences in DNAm between affected and unaffected of twins. Our findings suggest that abnormalities of DNA methylation patterns, known to regulate gene transcription, may be involved in the pathogenesis of T1D. PMID:24210274

  10. Modulation of T cell responses to recall antigens presented by Langerhans cells in HIV-discordant identical twins by anti-interleukin (IL)-10 antibodies and IL-12.

    PubMed Central

    Blauvelt, A; Chougnet, C; Shearer, G M; Katz, S I

    1996-01-01

    Decreased antigen (Ag)-specific T cell (TC) proliferation and IL-2 production are detected in all stages of HIV disease. To determine whether dendritic cell dysfunction and/or abnormal cytokine production contribute to HIV-induced immune dysregulation, we studies TC responses to recall Ags (influenza virus and tetanus toxoid) presented by Langerhans cells (LC) in six pairs of HIV-discordant identical twins, and the modulation of these responses by anti-IL-10 (alphaIL-10) mAbs and IL-12. LC from HIV+ twins induced IL-2 comparable to normal LC in cultures containing TC from uninfected twins. In contrast, IL-2 production was markedly decreased in cultures containing TC from HIV+ twins. IL-12 enhanced Ag-specific IL-2 production by TC from two patients with CD4+ counts > 600. In contrast, alphaIL-10 mAbs enhanced IL-2 production in influenza virus-stimulated cultures containing TC from two patients with CD4+ counts < 20. Thus, these findings suggest that immunologic dysfunction of dendritic cells does not contribute to impaired secondary immune responses in HIV+ individuals. Although few patients were studied, partial immune reconstitution in vitro, as demonstrated here, may help to predict those individuals who might benefit from cytokines or antibodies against cytokines as immunotherapy for HIV disease. PMID:8617889

  11. Personality and birth order in monozygotic twins adopted apart: a test of Sulloway's theory; Research Reviews: twin births and cancer risk in mothers, male sexual dysfunction, twin study of ultimatum game behavior; Human Interest: 'The Land of Twins', twin-like reunion-I, twin-like reunion-II.

    PubMed

    Segal, Nancy L

    2008-02-01

    A brief overview of Sulloway's (1996) theory of birth order and personality is presented. A reared apart twin approach for testing his personality findings regarding openness to experience and conscientiousness in first borns and later borns is described. This is followed by summaries of three recent twin studies. The topics include cancer risk in mother of twins, sexual dysfunction in males and responder behavior during ultimatum games. This article concludes with a discussion of twinning rates and rituals among the Yoruba of western Nigeria, and descriptions of two unusual reunions between siblings and twins.

  12. Familial risk and ADHD-specific neural activity revealed by case-control, discordant twin pair design.

    PubMed

    Godinez, Detre A; Willcutt, Erik G; Burgess, Gregory C; Depue, Brendan E; Andrews-Hanna, Jessica R; Banich, Marie T

    2015-09-30

    Individuals with ADHD, as well as their family members who do not meet clinical criteria, have shown deficits in executive function. However, it remains unclear whether underlying neural alterations are familial or ADHD-specific. To investigate this issue, neural activation underlying executive function was assessed using functional magnetic resonance imaging during performance of a Stroop task in three groups of individuals: 20 young adults who were diagnosed with ADHD in childhood, their 20 dizygotic co-twins without ADHD in childhood, and 20 unrelated controls selected from dizygotic twin pairs in which neither twin had ADHD in childhood (total n=60). Implicating the frontoparietal network as a location of effects specific to ADHD, activation in the superior frontal (Brodmann's Area - BA 6) and parietal regions (BA 40) was significantly reduced in twins with childhood ADHD compared to both their control co-twins and unrelated control twins. Consistent with familial influences, activity in the anterior cingulate and insula was significantly reduced in both the twins with ADHD and their co-twins compared to the unrelated controls. These results show that both ADHD-specific and familial influences related to an ADHD diagnosis impact neural systems underlying executive function. PMID:26256128

  13. Different patterns of X inactivation in MZ twins discordant for red-green color-vision deficiency.

    PubMed Central

    Jørgensen, A L; Philip, J; Raskind, W H; Matsushita, M; Christensen, B; Dreyer, V; Motulsky, A G

    1992-01-01

    Two female identical twins who were clinically normal were obligatory heterozygotes for X-linked deuteranomaly associated with a green-red fusion gene derived from their deuteranomalous father. On anomaloscopy, one of the twins was phenotypically deuteranomalous while the other had normal color vision. The color vision-defective twin had two sons with normal color vision and one deuteranomalous son. X-inactivation analysis was done with the highly informative probe M27 beta. This probe detects a locus (DXS255) which contains a VNTR and which is somewhat differentially methylated on the active and inactive X chromosomes. In skin cells of the color vision-defective twin, almost all paternal X chromosomes with the abnormal color-vision genes were active, thereby explaining her color-vision defect. In contrast, a different pattern was observed in skin cells from the woman with normal color vision; her maternal X chromosome was mostly active. However, in blood lymphocytes, both twins showed identical patterns with mixtures of inactivated maternal and paternal X chromosomes. Deuteranomaly in one of the twins is explained by extremely skewed X inactivation, as shown in skin cells. Failure to find this skewed pattern in blood cells is explained by the sharing of fetal circulation and exchange of hematopoietic precursor cells between twins. These data give evidence for X inactivation of the color-vision locus and add another MZ twin pair with markedly different X-inactivation patterns for X-linked traits. Images Figure 2 PMID:1642230

  14. CNV Concordance in 1,097 MZ Twin Pairs.

    PubMed

    Abdellaoui, Abdel; Ehli, Erik A; Hottenga, Jouke-Jan; Weber, Zachary; Mbarek, Hamdi; Willemsen, Gonneke; van Beijsterveldt, Toos; Brooks, Andrew; Hudziak, Jim J; Sullivan, Patrick F; de Geus, Eco J; Davies, Gareth E; Boomsma, Dorret I

    2015-02-01

    Monozygotic (MZ) twins are genetically identical at conception, making them informative subjects for studies on somatic mutations. Copy number variants (CNVs) are responsible for a substantial part of genetic variation, have relatively high mutation rates, and are likely to be involved in phenotypic variation. We conducted a genome-wide survey for post-twinning de novo CNVs in 1,097 MZ twin pairs. Comparisons between MZ twins were made by CNVs measured in DNA from blood or buccal epithelium with the Affymetrix 6.0 microarray and two calling algorithms. In addition, CNV concordance rates were compared between the different sources of DNA, and gene-enrichment association analyses were conducted for thought problems (TP) and attention problems (AP) using CNVs concordant within MZ pairs. We found a total of 153 putative post-twinning de novo CNVs >100 kb, of which the majority resided in 15q11.2. Based on the discordance of raw intensity signals a selection was made of 20 de novo CNVs for a qPCR validation experiments. Two out of 20 post-twinning de novo CNVs were validated with qPCR in the same twin pair. The 13-year-old MZ twin pair that showed two discordances in CN in 15q11.2 in their buccal DNA did not show large phenotypic differences. From the remaining 18 putative de novo CNVs, 17 were deletions or duplications that were concordant within MZ twin pairs. Concordance rates within twin pairs of CNV calls with CN ≠ 2 were ~80%. Buccal epithelium-derived DNA showed a slightly but significantly higher concordance rate, and blood-derived DNA showed significantly more concordant CNVs per twin pair. The gene-enrichment analyses on concordant CNVs showed no significant associations between CNVs overlapping with genes involved in neuronal processes and TP or AP after accounting for the source of DNA. PMID:25578775

  15. Autism multiplex family with 16p11.2p12.2 microduplication syndrome in monozygotic twins and distal 16p11.2 deletion in their brother.

    PubMed

    Tabet, Anne-Claude; Pilorge, Marion; Delorme, Richard; Amsellem, Frédérique; Pinard, Jean-Marc; Leboyer, Marion; Verloes, Alain; Benzacken, Brigitte; Betancur, Catalina

    2012-05-01

    The pericentromeric region of chromosome 16p is rich in segmental duplications that predispose to rearrangements through non-allelic homologous recombination. Several recurrent copy number variations have been described recently in chromosome 16p. 16p11.2 rearrangements (29.5-30.1 Mb) are associated with autism, intellectual disability (ID) and other neurodevelopmental disorders. Another recognizable but less common microdeletion syndrome in 16p11.2p12.2 (21.4 to 28.5-30.1 Mb) has been described in six individuals with ID, whereas apparently reciprocal duplications, studied by standard cytogenetic and fluorescence in situ hybridization techniques, have been reported in three patients with autism spectrum disorders. Here, we report a multiplex family with three boys affected with autism, including two monozygotic twins carrying a de novo 16p11.2p12.2 duplication of 8.95 Mb (21.28-30.23 Mb) characterized by single-nucleotide polymorphism array, encompassing both the 16p11.2 and 16p11.2p12.2 regions. The twins exhibited autism, severe ID, and dysmorphic features, including a triangular face, deep-set eyes, large and prominent nasal bridge, and tall, slender build. The eldest brother presented with autism, mild ID, early-onset obesity and normal craniofacial features, and carried a smaller, overlapping 16p11.2 microdeletion of 847 kb (28.40-29.25 Mb), inherited from his apparently healthy father. Recurrent deletions in this region encompassing the SH2B1 gene were recently reported in early-onset obesity and in individuals with neurodevelopmental disorders associated with phenotypic variability. We discuss the clinical and genetic implications of two different 16p chromosomal rearrangements in this family, and suggest that the 16p11.2 deletion in the father predisposed to the formation of the duplication in his twin children. PMID:22234155

  16. Mixed-Handedness in Identical Twins Discordant for Combat Exposure in Vietnam: Relationship to Posttraumatic Stress Disorder.

    PubMed

    Goetz, Jared M; Pitman, Seth R; Tanev, Kaloyan S; Pitman, Roger K; Chemtob, Claude M

    2016-01-01

    This study evaluated the degree of mixed-handedness in predominantly right-handed Vietnam combat veteran twins and their identical, combat-unexposed cotwins. The "high-risk" cotwins of combat veterans with combat-related posttraumatic stress disorder (PTSD) had more mixed-handedness (i.e., less right-handedness) than the "low-risk" cotwins of combat veterans without PTSD. Self-reported combat exposure in combat-exposed twins was a mediator of the association between handedness in their unexposed cotwins and PTSD in the twins themselves. We conclude that mixed-handedness is a familial risk factor for combat-related PTSD. This risk may be mediated in part by a proclivity for mixed-handed soldiers and Marines to experience heavier combat. PMID:26404173

  17. Ontogenetic de novo copy number variations (CNVs) as a source of genetic individuality: studies on two families with MZD twins for schizophrenia.

    PubMed

    Maiti, Sujit; Kumar, Kiran Halagur Bhoge Gowda; Castellani, Christina A; O'Reilly, Richard; Singh, Shiva M

    2011-01-01

    Genetic individuality is the foundation of personalized medicine, yet its determinants are currently poorly understood. One issue is the difference between monozygotic twins that are assumed identical and have been extensively used in genetic studies for decades. Here, we report genome-wide alterations in two nuclear families each with a pair of monozygotic twins discordant for schizophrenia evaluated by the Affymetrix 6.0 human SNP array. The data analysis includes characterization of copy number variations (CNVs) and single nucleotide polymorphism (SNPs). The results have identified genomic differences between twin pairs and a set of new provisional schizophrenia genes. Samples were found to have between 35 and 65 CNVs per individual. The majority of CNVs (~80%) represented gains. In addition, ~10% of the CNVs were de novo (not present in parents), of these, 30% arose during parental meiosis and 70% arose during developmental mitosis. We also observed SNPs in the twins that were absent from both parents. These constituted 0.12% of all SNPs seen in the twins. In 65% of cases these SNPs arose during meiosis compared to 35% during mitosis. The developmental mitotic origin of most CNVs that may lead to MZ twin discordance may also cause tissue differences within individuals during a single pregnancy and generate a high frequency of mosaics in the population. The results argue for enduring genome-wide changes during cellular transmission, often ignored in most genetic analyses. PMID:21399695

  18. NK cells from an AML patient have recovered in remission and reached comparable cytolytic activity to that of a healthy monozygotic twin mediated by the single-chain triplebody SPM-2

    PubMed Central

    2013-01-01

    Background The capacity of patient’s Natural Killer cells (NKs) to be activated for cytolysis is an important prerequisite for the success of antibody-derived agents such as single-chain triplebodies (triplebodies) in cancer therapy. NKs recovered from AML patients at diagnosis are often found to be reduced in peripheral blood titers and cytolytic activity. Here, we had the unique opportunity to compare blood titers and cytolytic function of NKs from an AML patient with those of a healthy monozygotic twin. The sibling’s NKs were compared with the patient’s drawn either at diagnosis or in remission after chemotherapy. The cytolytic activities of NKs from these different sources for the patient’s autologous AML blasts and other leukemic target cells in conjunction with triplebody SPM-2, targeting the surface antigens CD33 and CD123 on the AML cells, were compared. Methods Patient NKs drawn at diagnosis were compared to NKs drawn in remission after chemotherapy and a sibling’s NKs, all prepared from PBMCs by immunomagnetic beads (MACS). Redirected lysis (RDL) assays using SPM-2 and antibody-dependent cellular cytotoxicity (ADCC) assays using the therapeutic antibody RituximabTM were performed with the enriched NKs. In addition, MACS-sorted NKs were analyzed for NK cell activating receptors (NCRs) by flow cytometry, and the release of TNF-alpha and IFN-gamma from blood samples of both siblings after the addition of the triplebody were measured in ELISA-assays. Results Patient NKs isolated from peripheral blood drawn in remission produced comparable lysis as NKs from the healthy twin against the patient’s autologous bone marrow (BM) blasts, mediated by SPM-2. The NCR receptor expression profiles on NKs from patient and twin were similar, but NK cell titers in peripheral blood were lower for samples drawn at diagnosis than in remission. Conclusions Peripheral blood NK titers and ex vivo cytolytic activities mediated by triplebody SPM-2 were comparable for

  19. The Accuracy of Estimating Fetal Weight and Inter-Twin Weight Discordance by Ultrasound in Twin Pregnancies in Women With Increased Body Mass Index.

    PubMed

    Al-Obaidly, Sawsan; Parrish, Jacqueline; Murphy, Kellie E; Glanc, Phyllis; Maxwell, Cynthia

    2015-08-01

    Objectifs : Cette étude avait pour objectif de déterminer si la présence d’un IMC maternel prégrossesse accru entraînait une baisse de la précision de l’échographie pour ce qui est de l’estimation du poids fœtal et de la discordance intergémellaire en matière de poids dans le cadre de grossesses gémellaires, par comparaison avec des femmes présentant un IMC normal. Méthodes : Nous avons mené une étude de cohorte rétrospective portant sur des femmes qui présentaient un IMC prégrossesse (ou aux débuts de la grossesse) connu, qui ont accouché après 28 semaines de gestation à la suite d’une grossesse gémellaire viable entre 2008 et 2011, et qui ont subi un examen échographique visant l’estimation du poids fœtal dans les deux semaines ayant précédé l’accouchement. Le poids fœtal estimé (PFE) par échographie a été comparé au poids réel de chacun des jumeaux, puis la discordance intergémellaire en matière de poids (définie comme une différence de poids entre les jumeaux de plus de 25 %) a été stratifiée en fonction de l’IMC de la patiente. Nous avons cherché à déterminer si le PFE et la discordance intergémellaire en matière de poids avaient été affectés lorsque l’accouchement était survenu de 8 à 14 jours à la suite de l’échographie, par comparaison avec un accouchement étant survenu dans les sept jours de la tenue de l’échographie. Résultats : Nous avons pu identifier, au total, 300 grossesses gémellaires pour lesquelles l’IMC maternel prégrossesse était connu : 179 femmes présentaient une insuffisance pondérale ou un poids normal (IMC < 25 kg/m(2)), 67 présentaient une surcharge pondérale (IMC = de 25 à 29,9 kg/m(2)) et 54 étaient obèses (IMC ≥ 30 kg/m(2)). Dans tous les groupes d’IMC, la précision de l’échographie menée entre 8 et 14 jours avant l’accouchement a été comparée à celle de l’échographie menée dans les sept jours de l

  20. Myasthenia gravis occurring in twins

    PubMed Central

    Namba, T.; Shapiro, M. S.; Brunner, N. G.; Grob, D.

    1971-01-01

    Myasthenia gravis in one member each of two sets of twins is described. A 17 year old girl developed generalized myasthenia gravis at the age of 14 years, while her monozygotic twin sister has remained in good health during a three year period of observation. Another patient was a 19 year old woman with the onset of generalized myasthenia gravis at the age of 11 years, and her dizygotic twin sister has been in good health. Myasthenia gravis has been described in 13 sets of monozygotic twins, seven sets of dizygotic twins, and one set of twins with undetermined zygosity. Both members of twins were affected in five sets of monozygotic twins and one set of twins with undetermined zygosity, and only one twin was affected in the remaining sets of twins. Occurrence of myasthenia gravis in both members of monozygotic twins and in none of dizygotic twins, and frequent familial occurrence of the disease suggest the role of a genetic factor in the pathogenesis of this disease. PMID:5122380

  1. One-year developmental stability and covariance among oddball, novelty, go/no-go, and flanker event-related potentials in adolescence: A monozygotic twin study.

    PubMed

    Burwell, Scott J; Malone, Stephen M; Iacono, William G

    2016-07-01

    ERP measures may index genetic risk for psychopathology before disorder onset in adolescence, but little is known about their developmental rank-order stability during this period of significant brain maturation. We studied ERP stability in 48 pairs of identical twins (age 14-16 years) tested 1 year apart. Trial-averaged voltage waveforms were extracted from electroencephalographic recordings from oddball/novelty, go/no-go, and flanker tasks, and 16 amplitude measures were examined. Members of twin pairs were highly similar, whether based on ERP amplitude measures (intraclass correlation [ICC] median = .64, range = .44-.86) or three factor scores (all ICCs ≥ .69) derived from them. Stability was high overall, with 69% of the 16 individual measures generating stability coefficients exceeding .70 and all factor scores showing stability above .75. Measures from 10 difference waveforms calculated from paired conditions within tasks were also examined, and were associated with lower twin similarity (ICC median = .52, .38-.64) and developmental stability (only 30% exceeding .70). In a supplemental analysis, we found significant developmental stability for error-related negativity (range = .45-.55) and positivity (.56-.70) measures when average waveforms were based on one or more trials, and that these values were equivalent to those derived from averages using the current field recommendation, which requires six or more trials. Overall, we conclude that the studied brain measures are largely stable over 1 year of mid- to late adolescence, likely reflecting familial etiologic influences on brain functions pertaining to cognitive control and salience recognition.

  2. [Possible role of the cytoplasm in the course of morphogenesis, namely, in the case of twinning].

    PubMed

    Giroud, A

    1975-01-01

    A number of facts that cannot be interpreted in terms of nuclear genes would seem to be interpretable in terms of cytoplasmic heredity. The hereditary role of the mitochondria has already been demonstrated in molds. The role of the cytoplasm (matrilineal heredity) has also been shown in some phanerogams, and analogous facts have been noted in insects and molluscs. In amphibians, the influence of an alteration of the egg cortical cytoplasm has been shown to reappear in the following generations. This cortical cytoplasm includes the morphological plan of the organism with its bilateral symmetry. In Tatusia novemcincta the twins may be morphologically or chemically different, which may only be explained by an unequal subdivision of a heterogenic cytoplasm. Similar facts are observed in human twinning. Monozygotic twins are usually discordant with respect to congenital malformations (especially symmelia and anencephaly), which may only be interpreted in terms of unequal distribution of cytoplasmic properties.

  3. [Possible role of the cytoplasm in the course of morphogenesis, namely, in the case of twinning].

    PubMed

    Giroud, A

    1975-01-01

    A number of facts that cannot be interpreted in terms of nuclear genes would seem to be interpretable in terms of cytoplasmic heredity. The hereditary role of the mitochondria has already been demonstrated in molds. The role of the cytoplasm (matrilineal heredity) has also been shown in some phanerogams, and analogous facts have been noted in insects and molluscs. In amphibians, the influence of an alteration of the egg cortical cytoplasm has been shown to reappear in the following generations. This cortical cytoplasm includes the morphological plan of the organism with its bilateral symmetry. In Tatusia novemcincta the twins may be morphologically or chemically different, which may only be explained by an unequal subdivision of a heterogenic cytoplasm. Similar facts are observed in human twinning. Monozygotic twins are usually discordant with respect to congenital malformations (especially symmelia and anencephaly), which may only be interpreted in terms of unequal distribution of cytoplasmic properties. PMID:1242075

  4. Antenatal Diagnosis of Dizygotic, Monochorionic Twins Following IVF/ICSI

    PubMed Central

    Korsun, P.; Bals-Pratsch, M.; Ortmann, O.; Markus, S.; Germer, U.

    2016-01-01

    Monochorionic twins are usually monozygotic and thus usually have the same sex. A case of monochorionic diamniotic twins following IVF/ICSI and laser treatment of the zona pellucida (“assisted hatching”) is presented in which partial embryo amalgamation appears to have occurred. Discordant sex between the twins was suspected on detailed antenatal ultrasound at 13 + 3 weeks gestation and was confirmed on subsequent examinations. The sexual phenotype at birth was female for one twin and male for the other. Placental histology confirmed the monochorionic, diamniotic situation. Cytogenetic analysis of both twins was carried out postpartum on various tissues. On karyotyping of blood lymphocytes the male and female twins each had one mosaic of male and female cells. Oral mucosal cells showed normal male and female karyotypes respectively. Analysis of urothelium showed a normal result for the male infant, and a weak gonosomal mosaic with an XX and XY constellation for the female infant. At least for blood lymphocytes, a diagnosis of chimerism was proven. PMID:27365544

  5. Twin studies of schizophrenia: from bow-and-arrow concordances to star wars Mx and functional genomics.

    PubMed

    Cardno, A G; Gottesman, I I

    2000-01-01

    Twin studies have been vital for establishing an important genetic contribution to the etiology of schizophrenia. The five newest studies since 1995 from Europe and Japan have confirmed earlier findings. They yielded probandwise concordance rates of 41-65% in monozygotic (MZ) pairs and 0-28% in dizygotic (DZ) pairs, and heritability estimates of approximately 80-85%. Twin studies are also valuable for investigating the etiological relationships between schizophrenia and other disorders, and the genetic basis of clinical heterogeneity within schizophrenia. Studies of discordant MZ pairs provide further insights into non-inherited factors that contribute to the multifactorial etiology of this disorder. More recently, twin studies have begun to be used to directly investigate molecular genetic and epigenetic processes underlying schizophrenia.

  6. The Roots of Autism and ADHD Twin Study in Sweden (RATSS).

    PubMed

    Bölte, Sven; Willfors, Charlotte; Berggren, Steve; Norberg, Joakim; Poltrago, Lina; Mevel, Katell; Coco, Christina; Fransson, Peter; Borg, Jacqueline; Sitnikov, Rouslan; Toro, Roberto; Tammimies, Kristiina; Anderlid, Britt-Marie; Nordgren, Ann; Falk, Anna; Meyer, Urs; Kere, Juha; Landén, Mikael; Dalman, Christina; Ronald, Angelica; Anckarsäter, Henrik; Lichtenstein, Paul

    2014-06-01

    Neurodevelopmental disorders affect a substantial minority of the general population. Their origins are still largely unknown, but a complex interplay of genetic and environmental factors causing disturbances of the central nervous system's maturation and a variety of higher cognitive skills is presumed. Only limited research of rather small sample size and narrow scope has been conducted in neurodevelopmental disorders using a twin-differences design. The Roots of Autism and ADHD Twin Study in Sweden (RATSS) is an ongoing project targeting monozygotic twins discordant for categorical or dimensional autistic and inattentive/hyperactive-impulsive phenotypes as well as other neurodevelopmental disorders, and typically developing twin controls. Included pairs are 9 years of age or older, and comprehensively assessed for psychopathology, medical history, neuropsychology, and dysmorphology, as well as structural, functional, and molecular brain imaging. Specimens are collected for induced pluripotent (iPS) and neuroepithelial stem cells, genetic, gut bacteria, protein-/monoamine, and electron microscopy analyses. RATSS's objective is to generate a launch pad for novel surveys to understand the complexity of genotype-environment-phenotype interactions in autism spectrum disorder and attention-deficit hyperactivity disorder (ADHD). By October 2013, RATSS had collected data from 55 twin pairs, among them 10 monozygotic pairs discordant for autism spectrum disorder, seven for ADHD, and four for other neurodevelopmental disorders. This article describes the design, recruitment, data collection, measures, collected pairs' characteristics, as well as ongoing and planned analyses in RATSS. Potential gains of the study comprise the identification of environmentally mediated biomarkers, the emergence of candidates for drug development, translational modeling, and new leads for prevention of incapacitating outcomes.

  7. Reflections on twin relationships: twins reared apart and twins of opposite gender.

    PubMed

    Segal, Nancy L

    2012-12-01

    The complexities of twin relationships posed by separate rearing and by opposite sex are considered. Unusual cases may highlight unique social-interactional processes and outcomes occurring in these pairs. Research reviews include recent twin studies on second language acquisition, political behavior, and multiple birth rates. Items of more general interest include twin 'cousins' reared apart, indistinguishable monozygotic quadruplets, a genetic testing dilemma, and a performance about separated twins. PMID:23363461

  8. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins.

    PubMed

    Pinheiro, Marina B; Ferreira, Manuela L; Refshauge, Kathryn; Colodro-Conde, Lucía; Carrillo, Eduvigis; Hopper, John L; Ordoñana, Juan R; Ferreira, Paulo H

    2015-03-01

    Although the co-occurrence of low back pain (LBP) and depression is common, the nature of this association remains unclear. We aimed to investigate whether symptoms of depression are associated with LBP after adjusting for various confounders, including genetics. We used cross-sectional data from 2148 twins from the Murcia Twin Registry, Spain. All twins answered questions about lifetime prevalence of LBP (outcome variable) and symptoms of depression, collected through two instruments, deriving 3 measures: (1) self-report feelings of depression and anxiety; (2) state depression, and (3) trait depression. First, associations were investigated using logistic regression analysis of the total sample. We performed subsequent matched within-pair twin case-control analyses with all complete twin pairs discordant for LBP regardless of zygosity, and separately for dizygotic and monozygotic pairs. This sequential analysis allows for more precise estimates of the relationship between variables, as in each step, the impact of early shared environment and genetics is further considered. Symptoms of depression and anxiety were associated with higher prevalence of LBP in the total sample analysis (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.31-2.05), and this relationship was stronger in the subsequent case-control analysis (OR, 1.74; 95% CI, 1.13-2.69) and dizygotic case-control analysis (OR, 2.39; 95% CI, 1.39-4.08) but disappeared when the analysis was conducted for monozygotic twins (OR, 0.92; 95% CI, 0.42-2.05). A similar pattern was found for state and trait depression. The depression-LBP relationship disappears when high levels of control for confounding factors are applied and seems to be driven by genetic or environmental factors that influence both conditions. PMID:25679471

  9. Genetics and the environment affect the relationship between depression and low back pain: a co-twin control study of Spanish twins.

    PubMed

    Pinheiro, Marina B; Ferreira, Manuela L; Refshauge, Kathryn; Colodro-Conde, Lucía; Carrillo, Eduvigis; Hopper, John L; Ordoñana, Juan R; Ferreira, Paulo H

    2015-03-01

    Although the co-occurrence of low back pain (LBP) and depression is common, the nature of this association remains unclear. We aimed to investigate whether symptoms of depression are associated with LBP after adjusting for various confounders, including genetics. We used cross-sectional data from 2148 twins from the Murcia Twin Registry, Spain. All twins answered questions about lifetime prevalence of LBP (outcome variable) and symptoms of depression, collected through two instruments, deriving 3 measures: (1) self-report feelings of depression and anxiety; (2) state depression, and (3) trait depression. First, associations were investigated using logistic regression analysis of the total sample. We performed subsequent matched within-pair twin case-control analyses with all complete twin pairs discordant for LBP regardless of zygosity, and separately for dizygotic and monozygotic pairs. This sequential analysis allows for more precise estimates of the relationship between variables, as in each step, the impact of early shared environment and genetics is further considered. Symptoms of depression and anxiety were associated with higher prevalence of LBP in the total sample analysis (odds ratio [OR], 1.64; 95% confidence interval [CI], 1.31-2.05), and this relationship was stronger in the subsequent case-control analysis (OR, 1.74; 95% CI, 1.13-2.69) and dizygotic case-control analysis (OR, 2.39; 95% CI, 1.39-4.08) but disappeared when the analysis was conducted for monozygotic twins (OR, 0.92; 95% CI, 0.42-2.05). A similar pattern was found for state and trait depression. The depression-LBP relationship disappears when high levels of control for confounding factors are applied and seems to be driven by genetic or environmental factors that influence both conditions.

  10. Is that me or my twin? Lack of self-face recognition advantage in identical twins.

    PubMed

    Martini, Matteo; Bufalari, Ilaria; Stazi, Maria Antonietta; Aglioti, Salvatore Maria

    2015-01-01

    Despite the increasing interest in twin studies and the stunning amount of research on face recognition, the ability of adult identical twins to discriminate their own faces from those of their co-twins has been scarcely investigated. One's own face is the most distinctive feature of the bodily self, and people typically show a clear advantage in recognizing their own face even more than other very familiar identities. Given the very high level of resemblance of their faces, monozygotic twins represent a unique model for exploring self-face processing. Herein we examined the ability of monozygotic twins to distinguish their own face from the face of their co-twin and of a highly familiar individual. Results show that twins equally recognize their own face and their twin's face. This lack of self-face advantage was negatively predicted by how much they felt physically similar to their co-twin and by their anxious or avoidant attachment style. We speculate that in monozygotic twins, the visual representation of the self-face overlaps with that of the co-twin. Thus, to distinguish the self from the co-twin, monozygotic twins have to rely much more than control participants on the multisensory integration processes upon which the sense of bodily self is based. Moreover, in keeping with the notion that attachment style influences perception of self and significant others, we propose that the observed self/co-twin confusion may depend upon insecure attachment. PMID:25853249

  11. Is Chronic Low Back Pain Associated with the Prevalence of Coronary Heart Disease when Genetic Susceptibility Is Considered? A Co-Twin Control Study of Spanish Twins

    PubMed Central

    Fernandez, Matt; Ordoñana, Juan R.; Hartvigsen, Jan; Ferreira, Manuela L.; Refshauge, Kathryn M.; Sánchez-Romera, Juan F.; Pinheiro, Marina B.; Simpson, Stephen J.; Hopper, John L.; Ferreira, Paulo H.

    2016-01-01

    Objective To investigate the chronic low back pain and coronary heart disease relationship, after adjusting for relevant confounders, including genetics. Methods In a cross-sectional design, 2148 twins were recruited from the Murcia Twin Registry, Spain. The exposure was chronic LBP and the outcomes were myocardial infarction and other coronary heart diseases—lifetime and in the last 2 years–based on standardized health-related questionnaires. First, logistic regression analysis investigated associations of the total sample followed by a matched co-twin control analyses, with all complete twin pairs discordant for chronic LBP utilised, separated for zygosity—dizygotic (DZ) and monozygotic (MZ) pairs, which adjusted for shared familial factors, including genetics. Results Chronic LBP pain is associated with lifetime myocardial infarction [odds ratio (OR) = 2.69, 95% confidence interval (CI) = 1.35–5.36], other coronary heart diseases over a lifetime (OR = 2.58, 95% CI: 1.69–3.93) and in the last two years (OR = 2.19, 95% CI: 1.33–3.60), while there was a borderline association with myocardial infarction in the last 2 years (OR = 2.64, 95% CI: 0.98–7.12). Although the magnitude of the association remained or increased in the co-twin control analyses, none reached statistical significance. Conclusion Chronic LBP is associated with a higher prevalence of myocardial infarction and coronary heart disease. It is possible that this association remains even when controlling for genetics and early shared environment, although this should be investigated with larger samples of twins discordant for LBP. PMID:27171210

  12. Neonatal lupus erythematosus: discordant disease expression of U1RNP-positive antibodies in fraternal twins--is this a subset of neonatal lupus erythematosus or a new distinct syndrome?

    PubMed

    Solomon, B A; Laude, T A; Shalita, A R

    1995-05-01

    Neonatal lupus erythematosus (NLE) is an uncommon disease that is manifested by cutaneous lesions, cardiac conduction defects, or both, that appear in utero or shortly after birth. In approximately 95% of patients, anti-Ro antibody (Ro[SS-A]) has been identified and has become the serologic marker for NLE. Since 1987 there have been four reported cases of Ro- and anti-La antibody (La[SS-B])-negative, U1RNP antibody-positive, NLE. Our affected twin, as well as all other infants with U1RNP-positive NLE, had cutaneous lesions similar to those in Ro-positive NLE, although they lacked systemic abnormalities, including cardiac conduction defects. HLA typing of mothers with infants with U1RNP-positive NLE revealed the presence of HLA-DR4, DQw1, or DQw3 phenotypes. Our typing confirms these findings. As with Ro-positive NLE, no distinct HLA associations were demonstrated in the infants. Unlike Ro-positive mothers, all mothers with a U1RNP-positive infant with NLE had connective tissue disease at the time of the diagnosis and had a different spectrum of disease. We describe the clinical, serologic, and immunogenetic findings in the first reported case of U1RNP-positive NLE in dizygotic twins in whom the NLE disease expression was discordant. PMID:7722044

  13. DNA methylation analysis of multiple tissues from newborn twins reveals both genetic and intrauterine components to variation in the human neonatal epigenome.

    PubMed

    Ollikainen, Miina; Smith, Katherine R; Joo, Eric Ji-Hoon; Ng, Hong Kiat; Andronikos, Roberta; Novakovic, Boris; Abdul Aziz, Nur Khairunnisa; Carlin, John B; Morley, Ruth; Saffery, Richard; Craig, Jeffrey M

    2010-11-01

    Mounting evidence from both animal and human studies suggests that the epigenome is in constant drift over the life course in response to stochastic and environmental factors. In humans, this has been highlighted by a small number of studies that have demonstrated discordant DNA methylation patterns in adolescent or adult monozygotic (MZ) twin pairs. However, to date, it remains unclear when such differences emerge, and how prevalent they are across different tissues. To address this, we examined the methylation of four differentially methylated regions associated with the IGF2/H19 locus in multiple birth tissues derived from 91 twin pairs: 56 MZ and 35 dizygotic (DZ). Tissues included cord blood-derived mononuclear cells and granulocytes, human umbilical vein endothelial cells, buccal epithelial cells and placental tissue. Considerable variation in DNA methylation was observed between tissues and between unrelated individuals. Most interestingly, methylation discordance was also present within twin pairs, with DZ pairs showing greater discordance than MZ pairs. These data highlight the variable contribution of both intrauterine environmental exposures and underlying genetic factors to the establishment of the neonatal epigenome of different tissues and confirm the intrauterine period as a sensitive time for the establishment of epigenetic variability in humans. This has implications for the effects of maternal environment on the development of the newborn epigenome and supports an epigenetic mechanism for the previously described phenomenon of 'fetal programming' of disease risk. PMID:20699328

  14. Twin Studies in Autism: What Might They Say about Genetic and Environmental Influences

    ERIC Educational Resources Information Center

    Anderson, George M.

    2012-01-01

    Genetic and epigenetic differences exist within monozygote twin-pairs and might be especially important in the expression of autism. Assuming phenotypic differences between monozygotic twins are due to environmental influences may lead to mistaken conclusions regarding the relative genetic and environmental contribution to autism risk.

  15. Zygosity and intrauterine growth of twins.

    PubMed

    Grennert, L; Persson, P H; Gennser, G; Gullberg, B

    1980-06-01

    Six hundred seventy-eight sonar measurements of the fetal biparietal diameter (BPD) were used to assess the intrauterine growth of 182 twins between 18 and 40 weeks' gestation. These values, as well as the weight and body length at birth, were related to the zygosity, which was determined by sex of the infants, histologic examination of placenta, or blood grouping. The mean BPD of twin 1 was larger than that of twin 2 in both monozygotic and dizygotic pairs throughout the study period (P less than .001). The size of BPD of the dizygotic infants exceeded that of the monozygotic among both twin 1 (P less than .001) and twin 2 (P less than .001). The absolute intrapair differences of birth length and weight were larger among dizygotic than among monozygotic twins. These findings suggest that in late pregnancy a substantial one-way intertwin transfusion among monochorial twins does not occur frequently enough to mask the inherent genetically determined similarity between the twins. The appearance already in the second trimester of the difference in the longitudinally monitored BPD between monozygotic and dizygotic twins suggests that the discrepancy is determined early in gestation.

  16. Dogs Discriminate Identical Twins

    PubMed Central

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  17. Dogs discriminate identical twins.

    PubMed

    Pinc, Ludvík; Bartoš, Luděk; Reslová, Alice; Kotrba, Radim

    2011-01-01

    Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously. PMID:21698282

  18. Physically active vs. inactive lifestyle, muscle properties, and glucose homeostasis in middle-aged and older twins.

    PubMed

    Leskinen, T; Sipilä, S; Kaprio, J; Kainulainen, H; Alen, M; Kujala, U M

    2013-10-01

    Exercise-induced positive changes in skeletal muscle properties and metabolism decrease the risk for disability, cardiometabolic diseases and mortality. Here, we studied muscle properties and glucose homeostasis in a non-exercise stage in twin pairs with co-twins discordant for physical activity habits for at least 32 years of their adult lives. Isometric knee extension force, MR imaging of midthigh tissue composition and muscle volume, and fasting blood samples were acquired from 16 same-sex (seven monozygotic, nine dizygotic) middle-aged and older twin pairs. The consistently active twins had 20 % higher knee extension forces than their inactive co-twins (p = 0.006) although the active twins had only 4 % higher midthigh muscle cross-sectional areas (p = 0.072). These results were similar in intrapair analysis in which only the seven identical twin pairs were included. The ratio between the area of midthigh fat and muscle tissues was significantly lower among the active twins (0.65 vs. 0.48, p = 0.006). The active twins had also lower fasting plasma glucose levels (5.1 vs 5.6 mmol/l, p = 0.041). The area of midthigh intramuscular (extramyocellular) fat was associated with the markers of glucose homeostasis, especially with glycated hemoglobin, and these associations were emphasized by the diabetic and inactive twins. Regular exercise throughout the adult life retains muscle strength and quality but not necessarily mass. The regular use of muscles also prevents from the accumulation of intramuscular fat which might be related to maintained glucose metabolism and, thus, prevention of metabolic disorders. PMID:23124702

  19. Low birth weight and nephron mass and their role in the progression of chronic kidney disease: a case report on identical twins with Alport disease.

    PubMed

    Rajan, Tasleem; Barbour, Sean J; White, Colin T; Levin, Adeera

    2011-12-01

    We report the outcomes of 47-year-old monozygotic twins with Alport syndrome, who share the same maternal and genetic factors; however, in adulthood have discordant trajectories in the decline of their renal function. The twin with the more rapid progression to renal failure was born with low birth weight (LBW), suggesting congenital nephron deficiency and increased susceptibility to progressive renal disease, despite having the same genetically inherited kidney condition. This 'natural experiment' adds further credence to the hypothesis that LBW contributes to the susceptibility to chronic kidney disease. We suggest further studies and surveillance for this high-risk group of infants in order to gain additional insights into the impact of perinatal factors such as LBW. PMID:21565948

  20. The genetics of twinning: from splitting eggs to breaking paradigms.

    PubMed

    Shur, Natasha

    2009-05-15

    Over the last decades, there has been a twin boom in terms of live births. Meanwhile, new insights into the genetics of twinning have changed major paradigms. The first major paradigm is that monozygotic (MZ) twins are identical. The second is that twins are either MZ or dizygotic (DZ). The third is that MZ twins happen by chance alone. We have discovered striking epigenetic and other differences between seemingly alike individuals; the presence of fascinating intermediate twin forms; and the potential for familial MZ twinning and even a twinning gene. As this article discusses, the aforementioned paradigm shifts have influenced novel research directions and improved clinical approaches to twin-management.

  1. Cohort Profile: Swedish Twin Study on Prediction and Prevention of Asthma (STOPPA).

    PubMed

    Almqvist, Catarina; Örtqvist, Anne K; Ullemar, Vilhelmina; Lundholm, Cecilia; Lichtenstein, Paul; Magnusson, Patrik K E

    2015-06-01

    Asthma is a common childhood disease and several risk factors have been identified; however, the impact of genes and environment is not fully understood. The aim of the Swedish Twin study On Prediction and Prevention of Asthma (STOPPA) is to identify environmental (birth characteristics and early life) and genetic (including epigenetic) factors as determinants for asthmatic disease. Based on the Child and Adolescent Twin Study in Sweden (CATSS) (parental interview at 9 or 12 years, N ~23,900) and an asthma and/or wheezing algorithm, we identified a sample of monozygotic (MZ) and dizygotic (DZ) same-sexed twin pairs. The twin pairs were classified as asthma concordant (ACC), asthma discordant (ADC) and healthy concordant (HCC). A sample of 9- to 14-year-old twins and their parents were invited to participate in a clinical examination. Background characteristics were collected in questionnaires and obtained from the National Health Registers. A clinical examination was performed to test lung function and capacity (spirometry with reversibility test and exhaled nitric oxide) and collect blood (serology and DNA), urine (metabolites), feces (microbiota), and saliva (cortisol). In total, 376 twin pairs (752 individual twins) completed the study, response rate 52%. All participating twins answered the questionnaire and >90% participated in lung function testing, blood-, and saliva sampling. This article describes the design, recruitment, data collection, measures, and background characteristics, as well as ongoing and planned analyses in STOPPA. Potential gains of the study include the identification of biomarkers, the emergence of candidates for drug development, and new leads for prevention of asthma and allergic disease. PMID:25900604

  2. The 2016 Satellite Meeting of the International Society of Twin Studies: An Overview/Tribute to Irving I. Gottesman/Research: MZ Twinning After Single Embryo Transfer; Twin Study of Mononucleosis; Cerebral Injury After Twin-To-Twin Transfusion Syndrome Surgery/Human Interest: Sixteen Twin Pairs Born in a Single Hospital; Death of an Identical Twin Playwright; Twin Themes in Advertising; Conjoined Twins Separated in Saudi Arabia; Murder of One Twin By Her Co-Twin Disproved.

    PubMed

    Segal, Nancy L

    2016-10-01

    The 2016 Satellite Meeting of the International Society of Twin Studies took place on June 20 in Brisbane, Australia. The host institution was the QIMR Berghofer Medical Research Institute. An overview of selected presentations and activities is provided. This synopsis is followed by a brief tribute to the recent passing of our esteemed colleague, Dr Irving I. Gottesman. Next, there are summaries of research on monozygotic twinning after single embryo transfer, a twin study of mononucleosis susceptibility, cerebral injury following twin-to-twin transfusion syndrome surgery, and a correction and clarification regarding an article by Segal (2016) on the Brazilian Twin Registry. Human interest articles cover a hospital whose 2015 newborns included 16 pairs of twins born in 1 month, the death of an identical twin playwright, twin themes in advertising, conjoined twins separated in Saudi Arabia, and the dismissed charges of the murder of one twin by her co-twin.

  3. The 2016 Satellite Meeting of the International Society of Twin Studies: An Overview/Tribute to Irving I. Gottesman/Research: MZ Twinning After Single Embryo Transfer; Twin Study of Mononucleosis; Cerebral Injury After Twin-To-Twin Transfusion Syndrome Surgery/Human Interest: Sixteen Twin Pairs Born in a Single Hospital; Death of an Identical Twin Playwright; Twin Themes in Advertising; Conjoined Twins Separated in Saudi Arabia; Murder of One Twin By Her Co-Twin Disproved.

    PubMed

    Segal, Nancy L

    2016-10-01

    The 2016 Satellite Meeting of the International Society of Twin Studies took place on June 20 in Brisbane, Australia. The host institution was the QIMR Berghofer Medical Research Institute. An overview of selected presentations and activities is provided. This synopsis is followed by a brief tribute to the recent passing of our esteemed colleague, Dr Irving I. Gottesman. Next, there are summaries of research on monozygotic twinning after single embryo transfer, a twin study of mononucleosis susceptibility, cerebral injury following twin-to-twin transfusion syndrome surgery, and a correction and clarification regarding an article by Segal (2016) on the Brazilian Twin Registry. Human interest articles cover a hospital whose 2015 newborns included 16 pairs of twins born in 1 month, the death of an identical twin playwright, twin themes in advertising, conjoined twins separated in Saudi Arabia, and the dismissed charges of the murder of one twin by her co-twin. PMID:27524469

  4. Molecular analysis of the gut microbiota of identical twins with Crohn's disease

    SciTech Connect

    Jansson, Janet; Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt; Apajalahti, Juha; Engstrand, Lars; Jansson, Janet K.

    2008-03-14

    Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bacterial and Bacteroides group specific primers. The microbial communities were also profiled based on their % G+C contents. Bacteroides 16S rRNA genes were cloned and sequenced from a subset of the samples. The bacterial diversity in each sample and similarity indices between samples were estimated based on the T-RFLP data using a combination of statistical approaches. Healthy individuals had a significantly higher bacterial diversity compared to individuals with CD. The fecal microbial communities were more similar between healthy twins than between twins with CD, especially when these were discordant for the disease. The microbial community profiles of individuals with ileal CD were significantly different from healthy individuals and those with colonic CD. Also, CD individuals had a lower relative abundance of B. uniformis and higher relative abundances of B. ovatus and B. vulgatus. Our results suggest that genetics and/or environmental exposure during childhood in part determine the gut microbial composition. However, CD is associated with dramatic changes in the gut microbiota and this was particularly evident for individuals with ileal CD.

  5. Identical twins in forensic genetics - Epidemiology and risk based estimation of weight of evidence.

    PubMed

    Tvedebrink, Torben; Morling, Niels

    2015-12-01

    The increase in the number of forensic genetic loci used for identification purposes results in infinitesimal random match probabilities. These probabilities are computed under assumptions made for rather simple population genetic models. Often, the forensic expert reports likelihood ratios, where the alternative hypothesis is assumed not to encompass close relatives. However, this approach implies that important factors present in real human populations are discarded. This approach may be very unfavourable to the defendant. In this paper, we discuss some important aspects concerning the closest familial relationship, i.e., identical (monozygotic) twins, when reporting the weight of evidence. This can be done even when the suspect has no knowledge of an identical twin or when official records hold no twin information about the suspect. The derived expressions are not original as several authors previously have published results accounting for close familial relationships. However, we revisit the discussion to increase the awareness among forensic genetic practitioners and include new information on medical and societal factors to assess the risk of not considering a monozygotic twin as the true perpetrator. If accounting for a monozygotic twin in the weight of evidence, it implies that the likelihood ratio is truncated at a maximal value depending on the prevalence of monozygotic twins and the societal efficiency of recognising a monozygotic twin. If a monozygotic twin is considered as an alternative proposition, then data relevant for the Danish society suggests that the threshold of likelihood ratios should approximately be between 150,000 and 2,000,000 in order to take the risk of an unrecognised identical, monozygotic twin into consideration. In other societies, the threshold of the likelihood ratio in crime cases may reach other, often lower, values depending on the recognition of monozygotic twins and the age of the suspect. In general, more strictly kept

  6. Identical twins in forensic genetics - Epidemiology and risk based estimation of weight of evidence.

    PubMed

    Tvedebrink, Torben; Morling, Niels

    2015-12-01

    The increase in the number of forensic genetic loci used for identification purposes results in infinitesimal random match probabilities. These probabilities are computed under assumptions made for rather simple population genetic models. Often, the forensic expert reports likelihood ratios, where the alternative hypothesis is assumed not to encompass close relatives. However, this approach implies that important factors present in real human populations are discarded. This approach may be very unfavourable to the defendant. In this paper, we discuss some important aspects concerning the closest familial relationship, i.e., identical (monozygotic) twins, when reporting the weight of evidence. This can be done even when the suspect has no knowledge of an identical twin or when official records hold no twin information about the suspect. The derived expressions are not original as several authors previously have published results accounting for close familial relationships. However, we revisit the discussion to increase the awareness among forensic genetic practitioners and include new information on medical and societal factors to assess the risk of not considering a monozygotic twin as the true perpetrator. If accounting for a monozygotic twin in the weight of evidence, it implies that the likelihood ratio is truncated at a maximal value depending on the prevalence of monozygotic twins and the societal efficiency of recognising a monozygotic twin. If a monozygotic twin is considered as an alternative proposition, then data relevant for the Danish society suggests that the threshold of likelihood ratios should approximately be between 150,000 and 2,000,000 in order to take the risk of an unrecognised identical, monozygotic twin into consideration. In other societies, the threshold of the likelihood ratio in crime cases may reach other, often lower, values depending on the recognition of monozygotic twins and the age of the suspect. In general, more strictly kept

  7. Presence and Acquired Origin of Reduced Recall for Fear Extinction in PTSD: Results of a Twin Study

    PubMed Central

    Milad, Mohammed R.; Orr, Scott P.; Lasko, Natasha B.; Chang, Yuchiao; Rauch, Scott L.; Pitman, Roger K.

    2008-01-01

    Recall of fear extinction, which is thought to aid in recovery from a psychologically traumatic event, is hypothesized to be deficient in post-traumatic stress disorder (PTSD), but this has not yet been demonstrated in the laboratory, nor has its origin been investigated. To address these two issues, 14 pairs of monozygotic twins discordant for combat exposure, in 7 of which the combat-exposed twin had PTSD, underwent a two-day fear conditioning and extinction procedure. On Day 1, subjects viewed colored light conditioned stimuli, some of which were paired with mild electric shock, followed by extinction of the conditioned responses. On Day 2, recall of Day 1 extinction learning (i.e., extinction retention) was assessed. Skin conductance response (SCR) was the dependent measure. There were no group differences during acquisition or extinction learning. However, a significant PTSD Diagnosis (in the exposed twin) x combat Exposure interaction emerged during extinction recall, with the PTSD combat veterans having larger SCRs than their own co-twins, and than the non-PTSD combat veterans and their co-twins. These results indicate that retention of extinction of conditioned fear is deficient in PTSD. Furthermore, they support the conclusion that this deficit is acquired as a result of combat trauma leading to PTSD, rather than being a predisposing factor to developing PTSD upon the stress of combat. PMID:18313695

  8. Does educational status impact adult mortality in Denmark? A twin approach.

    PubMed

    Madsen, Mia; Andersen, Anne-Marie Nybo; Christensen, Kaare; Andersen, Per Kragh; Osler, Merete

    2010-07-15

    To disentangle an independent effect of educational status on mortality risk from direct and indirect selection mechanisms, the authors used a discordant twin pair design, which allowed them to isolate the effect of education by means of adjustment for genetic and environmental confounding per design. The study is based on data from the Danish Twin Registry and Statistics Denmark. Using Cox regression, they estimated hazard ratios for mortality according to the highest attained education among 5,260 monozygotic and 11,088 dizygotic same-sex twin pairs born during 1921-1950 and followed during 1980-2008. Both standard cohort and intrapair analyses were conducted separately for zygosity, gender, and birth cohort. Educational differences in mortality were demonstrated in the standard cohort analyses but attenuated in the intrapair analyses in all subgroups but men born during 1921-1935, and no effect modification by zygosity was observed. Hence, the results are most compatible with an effect of early family environment in explaining the educational inequality in mortality. However, large educational differences were still reflected in mortality risk differences within twin pairs, thus supporting some degree of independent effect of education. In addition, the effect of education may be more pronounced in older cohorts of Danish men.

  9. The effects of sibling relationships on social adjustment among Japanese twins compared with singletons.

    PubMed

    Nozaki, Mari; Fujisawa, Keiko K; Ando, Juko; Hasegawa, Toshikazu

    2012-12-01

    This study examined the link between sibling relationships and children's social adjustment by comparing twin siblings and siblings with different ages (singleton siblings}, and clarified the role of reciprocity in sibling relationships on children's social development. Mothers of 58 monozygotic twin pairs, 48 dizygotic twin pairs, and 86 singleton sibling pairs reported their children's sibling relationships and social adjustment.This study showed that the effects of sibling relationships on the prosocial behaviors and conduct problems of each child are stronger for twins than for singleton siblings. Moreover, positivity toward one's sibling increased peer problems only among monozygotic twins. The opposite tendency was present among dizygotic twins and singleton siblings. This study suggests the importance for children's social development of having many interactions with siblings and establishing reciprocity in sibling relationships. Moreover, our results suggest that the quality of sibling relationships among monozygotic twins may be different from those among dizygotic twins and singleton siblings.

  10. Twinning and heteropaternity in chimpanzees (Pan troglodytes).

    PubMed

    Ely, John J; Frels, William I; Howell, Sue; Izard, M Kay; Keeling, Michale E; Lee, D Rick

    2006-05-01

    Unlike monozygotic (MZ) twins, dizygotic (DZ) twins develop from separate ova. The resulting twins can have different sires if the fertilizing sperm comes from different males. Routine paternity testing of a pair of same-sexed chimpanzee twins born to a female housed with two males indicated that the twins were sired by two different males. DNA typing of 22 short-tandem repeat (STR) loci demonstrated that these twins were not MZ twins but heteropaternal DZ twins. Reproductive data from 1926-2002 at five domestic chimpanzee colonies, including 52 twins and two triplets in 1,865 maternities, were used to estimate total twinning rates and the MZ and DZ components. The average chimpanzee MZ twinning rate (0.43%) equaled the average human MZ rate (0.48%). However, the chimpanzee DZ twinning rate (2.36%) was over twice the human average, and higher than all but the fertility-enhanced human populations of Nigeria. Similarly high twinning rates among African chimpanzees indicated that these estimates were not artifacts of captivity. Log-linear analyses of maternal and paternal effects on recurrent twinning indicated that females who twinned previously had recurrence risks five times greater than average, while evidence for a paternal twinning effect was weak. Chimpanzee twinning rates appear to be elevated relative to corresponding estimated human rates, making twinning and possibly heteropaternity more important features of chimpanzee reproductive biology than previously recognized. PMID:16353220

  11. Sexual Behavior in Young Adulthood: A Population-Based Twin Study

    PubMed Central

    Mustanski, Brian; Viken, Richard J.; Kaprio, Jaakko; Winter, Torsten; Rose, Richard J.

    2007-01-01

    Objective With behavior genetic analyses of data from young adult twins, we evaluated theoretical perspectives that differentially emphasize biological dispositions, social/cultural factors, or universal pathways to explain individual differences in sexual behaviors. Design We fit biometric sex limitation models to three aspects of sexual behavior reported by 4,925 Finnish twins aged 23–27. The sample, from five consecutive birth cohorts, of 2,448 twin pairs (886 sister-sister, 862 brother-sister, 700 brother-brother), included 785 monozygotic and 801 same-sex dizygotic pairs. In addition to model fitting data from twin pairs, we conducted analyses on twins as individuals to test for independence of initiation of sexual behavior from onset age and number of partners. Main Outcome Measures From a postal questionnaire, we obtained self-report information on initiation/abstinence of sexual intercourse, onset age, and number of sexual partners. Results Genetic and non-shared environmental influences were significant for all three measures. There were trends for common environmental influences on initiation and, in females, age at first intercourse. Some differential effects in males and females were found. Results comparing onset age and number of partners among experienced twins from pairs concordant and discordant for initiation found genetic and environmental influences on initiation/abstinence overlapped those found for the other aspects of sexual behavior. Conclusions These results document genetic variation in individual differences in sexual behavior of young adults. Incorporating genetic dispositions into integrated models of sexual behavior will facilitate more effective health promotion and risk taking intervention. PMID:17845112

  12. Association of cognitive distortions with problem and pathological gambling in adult male twins.

    PubMed

    Xian, Hong; Shah, Kamini R; Phillips, Sharon M; Scherrer, Jeffrey F; Volberg, Rachel; Eisen, Seth A

    2008-09-30

    Treatment studies suggest that gambling-related irrational beliefs and attitudes (i.e., cognitive distortions (CDs)) contribute to the risk for problem gambling behavior. In a community sample of men, we investigated the associations among lifetime gambling-related CDs, psychiatric disorders other than pathological gambling , and problem gambling severity. Subjects were 1354 members of the Vietnam Era Twin Registry. Problem gambling and gambling-related CDs were derived from a 2002 interview using the National Opinion Research Center DSM-IV Screen for Gambling Problems (NODS). Exploratory factor analysis was performed with the 12 CD items to identify an underlying construct. Generalized linear models were computed to test for associations among CDs, psychiatric disorders other than pathological gambling, and gambling problem severity. Co-twin control analyses of monozygotic twin pairs discordant for problem gambling severity adjusted for genetic and shared environmental influences. Twelve CD items related to one underlying CD construct. After adjustment for lifetime psychiatric disorders, pathological gambling symptoms were positively associated with higher CD scores. Pathological gambling symptoms remained significantly associated with CD scores after controlling for genetic and shared environmental influence. These results provide empirical support for an association between gambling-related CDs and gambling problem severity, even after controlling for genetic and shared environmental influences and non-pathological gambling psychiatric disorders. Public health messages and therapeutic interventions that reinforce the randomness of gambling and draw attention to distorted thinking may prevent the development of problem gambling and improve treatment outcomes.

  13. Twins reunited: scientific and personal perspectives/twin research studies: multiple birth effects on IQ and body size; life style, muscles, and metabolism; monochorionic dizygotic twin with blood chimerism; amniocentesis for twins/twins in the media: identical doctors; freedom fighter for twins; twin scholarships; Auguste and Jean-Felix Piccard; twins born apart.

    PubMed

    Segal, Nancy L; Mulligan, Christy A

    2014-04-01

    A reunion of 38-year-old female monozygotic twins took place in Daegu, South Korea, on January 14, 2014. Scientific and personal perspectives on this extraordinary event are provided. A review of timely twin research follows, covering the effects of multiple births on IQ and body size, lifestyle and physical fitness associations, a rare case of a dizygotic twin with blood chimerism and definitional issues surrounding amniocentesis-related loss in multiple birth pregnancies. Interesting and informative mention of twins in the media includes twin doctors, a twin freedom fighter, the availability of college scholarships for twins, a new book about the Piccard family (two of whose members were twins), and co-twins born before and after the new year. A follow-up to a previous mention of identical twin biatheletes is also provided. PMID:24589452

  14. Twins: A cloning experience.

    PubMed

    Prainsack, Barbara; Spector, Tim D

    2006-11-01

    Drawing upon qualitative interviews with monozygotic (identical) twins sharing 100% of their genes, and with dizygotic (fraternal) twins and singletons as control groups, this paper explores what it means to be genetically identical. (The twins interviewed were from the TwinsUK register in London.) In the context of the ongoing debate on human reproductive cloning, it examines questions such as: To what extent do identical twins perceive their emotional and physical bond to be a result of their genetic makeup? What would they think if they had been deliberately created genetically identical? How would they feel about being genetically identical to a person who was born a few years earlier or later? First, our respondents ascribed no great significance to the role of genes in their understanding of what it means to be identical twins. Second, the opinion that human reproductive cloning would "interfere with nature", or "contradict God's will", was expressed by our respondents exclusively on the abstract level. The more our respondents were able to relate a particular invented cloning scenario to their own life-worlds, the lower the prevalence of the argument. Third, for all three groups of respondents, the scenario of having been born in one of the other groups was perceived as strange. Fourth, the aspect that our respondents disliked about cloning scenarios was the potential motives of the cloners. Without equating monozygotic twins directly with "clones", these results from "naturally" genetically identical individuals add a new dimension to what a future cloning situation could entail: The cloned person might possibly (a) perceive a close physical and emotional connection to the progenitor as a blessing; (b) suffer from preconceptions of people who regard physical likeness as a sign of incomplete individuality; and (c) perceive the idea of not having been born a clone of a particular person as unpleasant.

  15. Head Circumferences in Twins with and without Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Froehlich, Wendy; Cleveland, Sue; Torres, Andrea; Phillips, Jennifer; Cohen, Brianne; Torigoe, Tiffany; Miller, Janet; Fedele, Angie; Collins, Jack; Smith, Karen; Lotspeich, Linda; Croen, Lisa A.; Ozonoff, Sally; Lajonchere, Clara; Grether, Judith K.; Hallmayer, Joachim

    2013-01-01

    To determine the genetic relationship between head circumference (HC) and Autism Spectrum Disorders (ASDs). Twin pairs with at least one twin with an ASD were assessed. HCs in affected and unaffected individuals were compared, as were HC correlations in monozygotic and dizygotic pairs. 404 subjects, ages 4-18, were included. 20% of males and 27%…

  16. Variations in the Binary Conception Model in Twinning.

    ERIC Educational Resources Information Center

    Lord, Thomas R.

    1988-01-01

    Presents a brief summary of the transformation of a single fertilized ovum into a multi-celled human. Discusses the similarities and differences of identical and non-identical twins. Cites twin pairs that do not neatly fit the monozygotic or dizygotic schemes of human development. (RT)

  17. Childhood trauma and personality disorder criterion counts: a co-twin control analysis.

    PubMed

    Berenz, Erin C; Amstadter, Ananda B; Aggen, Steven H; Knudsen, Gun Peggy; Reichborn-Kjennerud, Ted; Gardner, Charles O; Kendler, Kenneth S

    2013-11-01

    Correlational studies consistently report relationships between childhood trauma (CT) and most personality disorder (PD) criteria and diagnoses. However, it is not clear whether CT is directly related to PDs or whether common familial factors (i.e., shared environment and/or genetic factors) better account for that relationship. The current study used a cotwin control design to examine support for a direct effect of CT on PD criterion counts. Participants were from the Norwegian Twin Registry (N = 2,780), including a subset (n = 898) of twin pairs (449 pairs, 45% monozygotic [MZ]) discordant for CT meeting DSM-IV Posttraumatic Stress Disorder Criterion A. All participants completed the Norwegian version of the Structured Interview for DSM-IV Personality. Significant associations between CT and all PD criterion counts were detected in the general sample; however, the magnitude of observed effects was small, with CT accounting for no more than approximately 1% of variance in PD criterion counts. A significant, yet modest, interactive effect was detected for sex and CT on Schizoid and Schizotypal PD criterion counts, with CT being related to these disorders among women but not men. After common familial factors were accounted for in the discordant twin sample, CT was significantly related to Borderline and Antisocial PD criterion counts, but no other disorders; however, the magnitude of observed effects was quite modest (r2 = .006 for both outcomes), indicating that the small effect observed in the full sample is likely better accounted for by common genetic and/or environmental factors. CT does not appear to be a key factor in PD etiology.

  18. Kicking Back Cognitive Ageing: Leg Power Predicts Cognitive Ageing after Ten Years in Older Female Twins

    PubMed Central

    Steves, Claire J.; Mehta, Mitul M.; Jackson, Stephen H.D.; Spector, Tim D.

    2016-01-01

    Background Many observational studies have shown a protective effect of physical activity on cognitive ageing, but interventional studies have been less convincing. This may be due to short time scales of interventions, suboptimal interventional regimes or lack of lasting effect. Confounding through common genetic and developmental causes is also possible. Objectives We aimed to test whether muscle fitness (measured by leg power) could predict cognitive change in a healthy older population over a 10-year time interval, how this performed alongside other predictors of cognitive ageing, and whether this effect was confounded by factors shared by twins. In addition, we investigated whether differences in leg power were predictive of differences in brain structure and function after 12 years of follow-up in identical twin pairs. Methods A total of 324 healthy female twins (average age at baseline 55, range 43-73) performed the Cambridge Neuropsychological Test Automated Battery (CANTAB) at two time points 10 years apart. Linear regression modelling was used to assess the relationships between baseline leg power, physical activity and subsequent cognitive change, adjusting comprehensively for baseline covariates (including heart disease, diabetes, blood pressure, fasting blood glucose, lipids, diet, body habitus, smoking and alcohol habits, reading IQ, socioeconomic status and birthweight). A discordant twin approach was used to adjust for factors shared by twins. A subset of monozygotic pairs then underwent magnetic resonance imaging. The relationship between muscle fitness and brain structure and function was assessed using linear regression modelling and paired t tests. Results A striking protective relationship was found between muscle fitness (leg power) and both 10-year cognitive change [fully adjusted model standardised β-coefficient (Stdβ) = 0.174, p = 0.002] and subsequent total grey matter (Stdβ = 0.362, p = 0.005). These effects were robust in discordant

  19. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review.

    PubMed

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  20. Atrioventricular Nodal Re-entry Tachycardia in Identical Twins: A Case Report and Literature Review

    PubMed Central

    Barake, Walid; Caldwell, Jane; Baranchuk, Adrian

    2013-01-01

    This report details the case of 17 year old identical twins who both presented with paroxysmal supraventricular tachycardia (PSVT). Electrophysiological studies revealed atrioventricular nodal reentry tachycardia (AVNRT) in both twins. Successful but technically challenging slow pathway ablation was performed in both twins. This is the first reported case of confirmed AVNRT in identical twins which adds strong evidence to heritability of the dual AV node physiology and AVNRT. A review of the current literature regarding PSVT in monozygotic twins is provided. PMID:23329875

  1. Gleanings from Identical Twins Studying Science.

    ERIC Educational Resources Information Center

    Mascazine, John R.

    This paper explains and summarizes the results of a study that investigated the ways in which monozygotic (identical) and dizygotic (fraternal) twins learn. Their individual learning style elements were specifically investigated according to the Dunn and Dunn model. This paper discusses the themes, unique needs, and characteristics monozygotic…

  2. A Pediatric Twin Study of Brain Morphometry

    ERIC Educational Resources Information Center

    Wallace, Gregory L.; Schmitt, J. Eric; Lenroot, Rhoshel; Viding, Essi; Ordaz, Sarah; Rosenthal, Michael A.; Molloy, Elizabeth A.; Clasen, Liv S.; Kendler, Kenneth S.; Neale, Michael C.; Giedd, Jay N.

    2006-01-01

    Background: Longitudinal pediatric neuroimaging studies have demonstrated increasing volumes of white matter and regionally-specific inverted U shaped developmental trajectories of gray matter volumes during childhood and adolescence. Studies of monozygotic and dyzygotic twins during this developmental period allow exploration of genetic and…

  3. A Twin Protection Effect? Explaining Twin Survival Advantages with a Two-Process Mortality Model

    PubMed Central

    2016-01-01

    Twin studies that focus on the correlation in age-at-death between twin pairs have yielded important insights into the heritability and role of genetic factors in determining lifespan, but less attention is paid to the biological and social role of zygosity itself in determining survival across the entire life course. Using data from the Danish Twin Registry and the Human Mortality Database, we show that monozygotic twins have greater cumulative survival proportions at nearly every age compared to dizygotic twins and the Danish general population. We examine this survival advantage by fitting these data with a two-process mortality model that partitions survivorship patterns into extrinsic and intrinsic mortality processes roughly corresponding to acute, environmental and chronic, biological origins. We find intrinsic processes confer a survival advantage at older ages for males, while at younger ages, all monozygotic twins show a health protection effect against extrinsic death akin to a marriage protection effect. While existing research suggests an increasingly important role for genetic factors at very advanced ages, we conclude that the social closeness of monozygotic twins is a plausible driver of the survival advantage at ages <65. PMID:27192433

  4. A Twin Protection Effect? Explaining Twin Survival Advantages with a Two-Process Mortality Model.

    PubMed

    Sharrow, David J; Anderson, James J

    2016-01-01

    Twin studies that focus on the correlation in age-at-death between twin pairs have yielded important insights into the heritability and role of genetic factors in determining lifespan, but less attention is paid to the biological and social role of zygosity itself in determining survival across the entire life course. Using data from the Danish Twin Registry and the Human Mortality Database, we show that monozygotic twins have greater cumulative survival proportions at nearly every age compared to dizygotic twins and the Danish general population. We examine this survival advantage by fitting these data with a two-process mortality model that partitions survivorship patterns into extrinsic and intrinsic mortality processes roughly corresponding to acute, environmental and chronic, biological origins. We find intrinsic processes confer a survival advantage at older ages for males, while at younger ages, all monozygotic twins show a health protection effect against extrinsic death akin to a marriage protection effect. While existing research suggests an increasingly important role for genetic factors at very advanced ages, we conclude that the social closeness of monozygotic twins is a plausible driver of the survival advantage at ages <65.

  5. Pathology of twin placentas with special attention to monochorionic twin placentas.

    PubMed

    Nikkels, P G J; Hack, K E A; van Gemert, M J C

    2008-12-01

    The risk of perinatal morbidity and mortality in twins is 3-7 times higher than in singletons. In comparison to dichorionic twins, monochorionic twins are at increased risk for perinatal mortality and serious morbidity. In both type of twins growth discordance can occur. Discordant growth of dichorionic twins could be due to differences in placental mass or differences in placental parenchymal lesions, whereas birth weight discordancy in monochorionic twins is caused by placental vascular anastomoses. In this review the different types of complications (acardiac twins, acute and chronic twin-twin transfusion syndrome) due to different combinations of vascular anastomoses are discussed in relation to a computer model developed to gain more insight into the development of the twin-twin transfusion syndrome. The angioarchitecture of 395 monochorionic twin placentas was studied. Mortality was highest in the absence of an arterio-arterial anastomosis (42%) and lowest in the presence of an arterio-arterial anastomosis (15%). If mortality occurred, pregnancies with double mortality usually had an arterio-arterial anastomosis. If pregnancies were complicated by one death, a veno-venous anastomosis is more likely to be present. In conclusion, monochorionic twin pregnancies are a high risk pregnancy with a high chance of both mortality and morbidity; placental characteristics are a major contributor to adverse outcome in these pregnancies.

  6. Marital Conflict and Conduct Problems in Children of Twins

    ERIC Educational Resources Information Center

    Harden, K. Paige; Turkheimer, Eric; Emery, Robert E.; D'Onofrio, Brian M.; Slutske, Wendy S.; Heath, Andrew C.; Martin, Nicholas G.

    2007-01-01

    The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14-39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine…

  7. Beyond Heritability: Twin Studies in Behavioral Research

    PubMed Central

    Johnson, Wendy; Turkheimer, Eric; Gottesman, Irving I.; Bouchard, Thomas J.

    2010-01-01

    The heritability of human behavioral traits is now well established, due in large measure to classical twin studies. We see little need for further studies of the heritability of individual traits in behavioral science, but the twin study is far from having outlived its usefulness. The existence of pervasive familial influences on behavior means that selection bias is always a concern in any study of the causal effects of environmental circumstances. Twin samples continue to provide new opportunities to identify causal effects with appropriate genetic and shared environmental controls. We discuss environmental studies of discordant twin pairs and twin studies of genetic and environmental transactions in this context. PMID:20625474

  8. Twin studies reveal specific imbalances in the mucosa-associated microbiota of patients with ileal Crohn's disease

    SciTech Connect

    Willing, B.; Halfvarson, J.; Dicksved, J.; Rosenquist, M.; Jarnerot, G.; Engstrand, L.; Tysk, C.; Jansson, J. K

    2008-08-15

    Large inter-individual variation in the composition of the intestinal microbiota between unrelated individuals has made it challenging to identify specific aspects of dysbiosis that lead to Crohn's disease. To reduce variations in exposure during establishment of the gut flora and influence of genotype, we studied the mucosaassociated microbiota of monozygotic twin pairs that were discordant (n=6) or concordant (n=4) for Crohn's disease. DNA was extracted from biopsies collected from 5 locations between the ileum and rectum. Bacterial 16S ribosomal RNA genes were amplified and community composition assessed by terminal-restriction fragment length polymorphism, cloning and sequencing and quantitative real-time PCR. The microbial compositions at all biopsy locations for each individual were similar, regardless of disease state, but there were differences between individuals. In particular, individuals with predominantly ileal Crohn's had a dramatically lower abundance (P<0.001) of Faecalibacterium prausnitzii and increased abundance (P<0.03) of Escherichia coli compared to healthy co-twins and those with Crohn's localized in the colon. This dysbiosis was significantly correlated to the disease phenotype rather than genotype. The reduced abundance of F. prausnitzii and increased abundance of E. coli are indicative of an ileal Crohn's disease phenotype, distinct from colonic Crohn's disease and the relative abundances of these specific bacterial populations are promising biomarker candidates for differential diagnosis of Crohn's and eventually customized treatment.

  9. Twin Mitochondrial Sequence Analysis.

    PubMed

    Bouhlal, Yosr; Martinez, Selena; Gong, Henry; Dumas, Kevin; Shieh, Joseph T C

    2013-09-01

    When applying genome-wide sequencing technologies to disease investigation, it is increasingly important to resolve sequence variation in regions of the genome that may have homologous sequences. The human mitochondrial genome challenges interpretation given the potential for heteroplasmy, somatic variation, and homologous nuclear mitochondrial sequences (numts). Identical twins share the same mitochondrial DNA (mtDNA) from early life, but whether the mitochondrial sequence remains similar is unclear. We compared an adult monozygotic twin pair using high throughput-sequencing and evaluated variants with primer extension and mitochondrial pre-enrichment. Thirty-seven variants were shared between the twin individuals, and the variants were verified on the original genomic DNA. These studies support highly identical genetic sequence in this case. Certain low-level variant calls were of high quality and homology to the mitochondrial DNA, and they were further evaluated. When we assessed calls in pre-enriched mitochondrial DNA templates, we found that these may represent numts, which can be differentiated from mtDNA variation. We conclude that twin identity extends to mitochondrial DNA, and it is critical to differentiate between numts and mtDNA in genome sequencing, particularly since significant heteroplasmy could influence genome interpretation. Further studies on mtDNA and numts will aid in understanding how variation occurs and persists. PMID:24040623

  10. Twin Reversed Arterial Perfusion (TRAP) Sequence; Characteristic Gray-Scale and Doppler Ultrasonography Findings.

    PubMed

    Buyukkaya, Ayla; Tekbas, Guven; Buyukkaya, Ramazan

    2015-07-01

    Twin reversed arterial perfusion (TRAP) sequence is a syndrome with poor prognosis, seen only in monochorionic monozygotic twin pregnancies. The incidence is one in 35.000 births and one in 100 monozygotic twin pregnancies. It is characterized with a recipient fetus exhibiting lethal anomalies including acardia and a pump fetus. Mortality is usually due to heart failure or premature labor caused by polyhydramnios of pump fetus. Herein, we report a case of TRAP sequence that emphasizes the importance of gray-scale and color Doppler imaging in the diagnosis and management of TRAP sequence.

  11. Brief Report: On the Concordance Percentages for Autistic Spectrum Disorder of Twins

    ERIC Educational Resources Information Center

    Bohm, Henry V.; Stewart, Melbourne G.

    2009-01-01

    In the development of genetic theories of Autistic Spectrum Disorder (ASD) various characteristics of monozygotic (MZ) and dizygotic (DZ) twins are often considered. This paper sets forth a possible refinement in the interpretation of the MZ twin concordance percentages for ASD underlying such genetic theories, and, drawing the consequences from…

  12. Twin Study on Heritability of Activity, Attention, and Impulsivity as Assessed by Objective Measures

    ERIC Educational Resources Information Center

    Heiser, Philip; Heinzel-Gutenbrunner, Monika; Frey, Joachim; Smidt, Judith; Grabarkiewicz, Justyna; Friedel, Susann; Kuhnau, Wolfgang; Schmidtke, Jorg; Remschmidt, Helmut; Hebebrand, Johannes

    2006-01-01

    Objective: The purpose of this study was to assess heritability of activity, attention, and impulsivity by comparing young monozygotic (MZ) twins with dizygotic (DZ) twins using objective measures. Method: The OPTAx test is an infrared motion analysis to record the movement pattern during a continuous performance test. Seventeen MZ and 12 same…

  13. Mental Representations of Attachment in Identical Female Twins with and without Conduct Problems

    ERIC Educational Resources Information Center

    Constantino, John N.; Chackes, Laura M.; Wartner, Ulrike G.; Gross, Maggie; Brophy, Susan L.; Vitale, Josie; Heath, Andrew C.

    2006-01-01

    Insecure mental representations of attachment, a nearly invariant feature of cluster B personality disorders, have never previously been studied in twins. We conducted the Adult Attachment Interview (AAI) on 33 pairs of monozygotic (MZ) female twins reared together as an initial exploration of causal influences on mental representations of…

  14. Seeking the Cause of Correlations among Mental Abilities: Large Twin Analysis in a National Testing Program.

    ERIC Educational Resources Information Center

    Page, Ellis B.; Jarjoura, David

    1979-01-01

    A computer scan of ACT Assessment records identified 3,427 sets of twins. The Hardy-Weinberg rule was used to estimate the proportion of monozygotic twins in the sample. Matrices of genetic and environmental influences were produced. The heaviest loadings were clearly in the genetic matrix. (SJL)

  15. Movement Disorders in a Twins Pair: A Casual Expression or Genetic Determination?

    ERIC Educational Resources Information Center

    Gennaro, Leonarda; Russo, Luigi; Losito, Luciana; Zaccaria, Alessia; De Rinaldis, Marta; Trabacca, Antonio

    2010-01-01

    A twin study is an excellent means of assessing the contribution of heritability to motor behaviour. We present a movement video-analysis of a monozygotic twins pair with a motor repertoire which is almost totally constituted by persistent and subcontinuous motor stereotypies. Purpose: The specific aim of this study is to verify the heritable…

  16. Familial occurrence of Wilms' tumor: nephroblastoma in one of monozygous twins and in another sibling.

    PubMed Central

    Juberg, R C; St Martin, E C; Hundley, J R

    1975-01-01

    We report the occurrence of pathologically documented Wilm's tumor in a 24-month-old male twin and just 9 months later in his 12-month-old male sibling. We considered the twins to be monozygotic because of their phenotypic similarities, the probability computed from analysis of blood groups, and the comparison of their dermatoglphics. There were no other persons in the kindred with either tumor or associated malformations, and the parents were not consanguineous. Because of the frequency of Wilm's tumor, the few instances of demonstrated occurrence in siblings seem insufficient to postulate monogenic determination. Concordance in monozygotic twins has simply not been proven. The monozygotic unaffected twin of our first patient has remained without evidence of tumor to 5 years, and, as long as he remains so, he appears to represent an exception to the hypothesis of the mutagenic origin of this childhood tumor. PMID:164771

  17. Art for twins: Yorùbá artists and their statues/twin research studies: twins' education and conceptions; diurnal preference; inherited eye diseases; ultrasound counseling when twins are conjoined/popular twin reports: twin sisters (the film); rare pregnancy; diet test; French twins reared apart and reunited.

    PubMed

    Segal, Nancy L

    2014-06-01

    The Yorùbá of Nigeria are well known for their high twinning rate and the statues they create to commemorate deceased twins. An impressive collection of this artwork was displayed at the University of California's Fowler Museum in Los Angeles between October 13, 2013 and March 2, 2014. An overview of this exhibit is provided. Next, twin research on maternal education and conception, diurnal preference, inherited eye diseases, and ultrasound counseling for couples with conjoined twins are briefly summarized. This article concludes with a discussion of media-based items related to twins. The topics include an award-winning twin film, a rare pregnancy, a diet test, and the separation and chance reunion of monozygotic female twins.

  18. Microscopic Particles in Two Fractions of Fresh Cerebrospinal Fluid in Twins with Schizophrenia or Bipolar Disorder and in Healthy Controls

    PubMed Central

    Johansson, Viktoria; Nybom, Rolf; Wetterberg, Lennart; Hultman, Christina M.; Cannon, Tyrone D.; Johansson, Anette G. M.; Ekman, Carl Johan; Landén, Mikael

    2012-01-01

    Background Using scanning electron microscopy, microscopic structures have been identified in fresh cerebrospinal fluid (CSF) in patients with schizophrenia and bipolar disorder, but only rarely in control subjects. However, it has not been determined whether these microscopic particles represent state or trait markers, i.e. if their presence is related to clinical manifestations of the disease or if they also can be found in as yet asymptomatic individuals with a genetic liability. This question can be addressed by studying twins discordant or concordant for schizophrenia or bipolar disorder. Methodology/Principal Findings We investigated microscopic structures in CSF in 102 individuals: 21 monozygotic and 16 dizygotic twins affected or not affected with schizophrenia, schizoaffective disorder or bipolar disorder and in 65 healthy singleton controls. A first and a second fraction of CSF was freshly applied on filters and examined by scanning electron microscopy technique. Spherical particles with lipid appearance averaging between 0.1 to 8.0 µm in diameter were detected in the center of the filter as well as located in the margins of larger aggregates binding in a viscous state. Structures were found in 12 of 17 probands, 5 of 12 healthy co-twins and 3 of 73 healthy controls. Thus, a positive microscopic finding significantly increased the likelihood of belonging to the proband group (OR = 48, 95% CL: 8.2–550, p<0.0001) and the co-twin-group (OR = 16, 95% CL: 2.0–218, p = 0.006). Age, sex, history of alcohol abuse or anxiety syndrome, somatic disorder and markers of acute inflammatory activity did not account for group differences; nor did exposure to psychotropic medication. Conclusion Presence of microscopic particles in CSF may possibly reflect trait dependent genetic or environmental vulnerability in patients with schizophrenia, schizoaffective disorder or bipolar disorder. PMID:23049916

  19. Four twins for a paradox: on "sensitive" twins and the biological counterpart of the "twin paradox".

    PubMed

    Ascioti, Fortunato A

    2009-03-01

    Monozygotic twin (MZT) epigenetic development, i.e., aging, diverges largely in time despite the initially very small genetic differences between MZTs. This fact is interpreted as a "sensitivity to initial conditions" phenomenon, a common property of either deterministic or stochastic chaotic systems. Some of the biotheoretical implications stemming from this empirical observation are briefly discussed here, while an actual measure of MZT epigenetic time divergence is given through an estimate of the (Stochastic) Lyapunov exponents (LEs) (i.e., the rate of exponential time divergence). These results suggest a reconsideration of the Langevin-Einstein thought experiment known as the "twin paradox." At least four twins are necessary in order to take into account the inertially independent divergent aging described here. Alternatively, LE estimates, like those given here, should be used. Finally suggested in the actual special-relativity experiments is the replacement of clocks with some nonlinear (chaotic) forced oscillator. PMID:19334992

  20. Four twins for a paradox: On ``sensitive'' twins and the biological counterpart of the ``twin paradox''

    NASA Astrophysics Data System (ADS)

    Ascioti, Fortunato A.

    2009-03-01

    Monozygotic twin (MZT) epigenetic development, i.e., aging, diverges largely in time despite the initially very small genetic differences between MZTs. This fact is interpreted as a "sensitivity to initial conditions" phenomenon, a common property of either deterministic or stochastic chaotic systems. Some of the biotheoretical implications stemming from this empirical observation are briefly discussed here, while an actual measure of MZT epigenetic time divergence is given through an estimate of the (Stochastic) Lyapunov exponents (LEs) (i.e., the rate of exponential time divergence). These results suggest a reconsideration of the Langevin-Einstein thought experiment known as the "twin paradox." At least four twins are necessary in order to take into account the inertially independent divergent aging described here. Alternatively, LE estimates, like those given here, should be used. Finally suggested in the actual special-relativity experiments is the replacement of clocks with some nonlinear (chaotic) forced oscillator.

  1. Aryl hydrocarbon hydroxylase in cultured lymphocytes of twins.

    PubMed Central

    Paigen, B; Ward, E; Steenland, K; Houten, L; Gurtoo, H L; Minowada, J

    1978-01-01

    Measurement of aryl hydrocarbon hydroxylase (AHH) in cultured lymphocytes of 18 monozygotic and 30 dizygotic twin pairs showed that basal and induced AHH activity and AHH inducibility are heritable traits. The data are consistent with AHH inducibility being determined by a single or a very few polymorphic genes. PMID:569973

  2. Peer Network Overlap in Twin, Sibling, and Friend Dyads

    ERIC Educational Resources Information Center

    McGuire, Shirley; Segal, Nancy L.

    2013-01-01

    Research suggests that sibling–peer connections are important for understanding adolescent problem behaviors. Using a novel behavioral genetic design, the current study investigated peer network overlap in 300 child–child pairs (aged 7-13 years) in 5 dyad types: monozygotic (MZ), dizygotic twins, full siblings (FSs), friend pairs, and virtual…

  3. DYZ1 arrays show sequence variation between the monozygotic males

    PubMed Central

    2014-01-01

    Background Monozygotic twins (MZT) are an important resource for genetical studies in the context of normal and diseased genomes. In the present study we used DYZ1, a satellite fraction present in the form of tandem arrays on the long arm of the human Y chromosome, as a tool to uncover sequence variations between the monozygotic males. Results We detected copy number variation, frequent insertions and deletions within the sequences of DYZ1 arrays amongst all the three sets of twins used in the present study. MZT1b showed loss of 35 bp compared to that in 1a, whereas 2a showed loss of 31 bp compared to that in 2b. Similarly, 3b showed 10 bp insertion compared to that in 3a. MZT1a germline DNA showed loss of 5 bp and 1b blood DNA showed loss of 26 bp compared to that of 1a blood and 1b germline DNA, respectively. Of the 69 restriction sites detected in DYZ1 arrays, MboII, BsrI, TspEI and TaqI enzymes showed frequent loss and or gain amongst all the 3 pairs studied. MZT1 pair showed loss/gain of VspI, BsrDI, AgsI, PleI, TspDTI, TspEI, TfiI and TaqI restriction sites in both blood and germline DNA. All the three sets of MZT showed differences in the number of DYZ1 copies. FISH signals reflected somatic mosaicism of the DYZ1 copies across the cells. Conclusions DYZ1 showed both sequence and copy number variation between the MZT males. Sequence variation was also noticed between germline and blood DNA samples of the same individual as we observed at least in one set of sample. The result suggests that DYZ1 faithfully records all the genetical changes occurring after the twining which may be ascribed to the environmental factors. PMID:24495361

  4. Australian-Antarctic discordance

    NASA Astrophysics Data System (ADS)

    Sempeéreé, Jean-Christophe; Palmer, Jeb; Christie, David M.; Phipps Morgan, Jason; Shor, Alexander N.

    1991-05-01

    The Australian-Antarctic discordance is a region of anomalous geophysical and geochemical properties along the mid-ocean ridge system. It includes the isotopic boundary between Pacific Ocean and Indian Ocean basalts. Its lavas have compositions consistent with low mantle temperatures and a relatively low overall extent of melting. These characteristics have been attributed to downward flow in the underlying mantle. New bathymetric and side-scan sonar data show that (1) the spreading axis within the discordance is predominantly characterized by a broad rift valley and segmentation characteristics typical of slow-spreading centers, (2) the isotopic boundary appears to be associated with unusual, chaotic sea floor, and (3) the spreading axis east of the discordance is characterized by an axial ridge typical of fast-spreading centers. These extreme variations, at an essentially constant (intermediate) spreading rate are consistent with differences in melt supply and mantle properties along the spreading axis within and east of the discordance, as suggested in previous studies.

  5. Inspection Time and Cognitive Abilities in Twins Aged 7 to 17 Years: Age-Related Changes, Heritability and Genetic Covariance

    ERIC Educational Resources Information Center

    Edmonds, Caroline J.; Isaacs, Elizabeth B.; Visscher, Peter M.; Rogers, Mary; Lanigan, Julie; Singhal, Atul; Lucas, Alan; Gringras, Paul; Denton, Jane; Deary, Ian J.

    2008-01-01

    We studied the age-related differences in inspection time and multiple cognitive domains in a group of monozygotic (MZ) and dizygotic (DZ) twins aged 7 to 17 years. Data from 111 twin pairs and 19 singleton siblings were included. We found clear age-related trends towards more efficient visual information processing in older participants. There…

  6. Twins with schizophrenia: genes or germs?

    PubMed

    Davis, J O; Phelps, J A

    1995-01-01

    High concordance for schizophrenia in monozygotic (MZ) twins is often cited as evidence for the etiological influence of genetics; however, even if twins are separated at birth, MZ twin concordance is influenced by the shared prenatal environment. Study of the placentation status of MZ twins provides a way to investigate some prenatal influences, including the possible role of viral infections. The probability of shared infections is likely to be greater in monochorionic MZ twin pairs than in dichorionic pairs because of shared fetal circulation in the monochorionic pairs. We drew from published twin studies and used reported concordance for handedness as a retrospective marker of placentation status. We found that MZ twin pairs with opposite-hand preferences were concordant for psychosis in 9 of 15 cases (60%), while only 18 of 56 twin pairs (32%) with same-hand preferences were concordant for psychosis. These results suggest that shared prenatal viral infection may account for much of the high concordance for schizophrenia in identical twins. PMID:7770735

  7. Twins and the paradox of dental-age estimations: a caution for researchers and clinicians.

    PubMed

    Pechníková, M; De Angelis, D; Gibelli, D; Vecchio, V; Cameriere, R; Zeqiri, B; Cattaneo, C

    2014-08-01

    The biological age difference among twins is frequently an issue in studies of genetic influence on various dental features, particularly dental development. The timing of dental development is a crucial issue also for many clinicians and researchers. The aim of this study was therefore to verify within groups of twins how dental development differs, by applying Demirjian's method, Mincer's charts of development of third molars and two of Cameriere's methods for dental age estimation, which are among the most popular methods both in the clinical and the forensic scenario. The sample consisted of 64 twin pairs: 21 monozygotic, 30 dizygotic same-sex and 13 dizygotic opposite-sex with an age range between 5.8 and 22.6 years. Dental age was determined from radiographs using the mentioned methods. Results showed that dental age of monozygotic twins is not identical even if they share all their genes. The mean intra-pair difference of monozygotic pairs was low and similar to the difference in dizygotic same-sex twins; the maximum difference between monozygotic twins, however, was surprisingly large (nearly two years). This should lead to some circumspection in the interpretation of systematic estimations of dental age both in the clinical and forensic scenario. PMID:24951409

  8. Twins and the paradox of dental-age estimations: a caution for researchers and clinicians.

    PubMed

    Pechníková, M; De Angelis, D; Gibelli, D; Vecchio, V; Cameriere, R; Zeqiri, B; Cattaneo, C

    2014-08-01

    The biological age difference among twins is frequently an issue in studies of genetic influence on various dental features, particularly dental development. The timing of dental development is a crucial issue also for many clinicians and researchers. The aim of this study was therefore to verify within groups of twins how dental development differs, by applying Demirjian's method, Mincer's charts of development of third molars and two of Cameriere's methods for dental age estimation, which are among the most popular methods both in the clinical and the forensic scenario. The sample consisted of 64 twin pairs: 21 monozygotic, 30 dizygotic same-sex and 13 dizygotic opposite-sex with an age range between 5.8 and 22.6 years. Dental age was determined from radiographs using the mentioned methods. Results showed that dental age of monozygotic twins is not identical even if they share all their genes. The mean intra-pair difference of monozygotic pairs was low and similar to the difference in dizygotic same-sex twins; the maximum difference between monozygotic twins, however, was surprisingly large (nearly two years). This should lead to some circumspection in the interpretation of systematic estimations of dental age both in the clinical and forensic scenario.

  9. Missed congenital hypothyroidism in an identical twin.

    PubMed

    Azam, Anita; Cutfield, Wayne; Mouat, Fran; Hofman, Paul L; Jefferies, Craig; Webster, Dianne; Gunn, Alistair Jan

    2012-10-01

    Newborn screening for congenital hypothyroidism has been remarkably effective, although rare cases of false negative screening have been reported in same sex twins, presumptively due to fetal blood exchange. We report a case in which the diagnosis of congenital hypothyroidism due to thyroid ectopia in a monozygotic twin was delayed by 8 months, with a normal newborn screening TSH level of 11 mIU/L blood (normal < 15 mIU/L) at 2 days of life. This is the first such case since the national New Zealand newborn screening programme introduced screening for congenital hypothyroidism in 1981 (30 years ago). Repeating thyroid studies at 14 days of age in same-sex twins has been advocated to avoid delayed diagnosis, but given the low risk, may not be cost effective. It is important to maintain a high index of suspicion in same-sex twin pregnancies of potential congenital hypothyroidism. PMID:22970836

  10. Neuropathologic assessment of dementia markers in identical and fraternal twins.

    PubMed

    Iacono, Diego; Volkman, Inga; Nennesmo, Inger; Pedersen, Nancy L; Fratiglioni, Laura; Johansson, Boo; Karlsson, David; Winblad, Bengt; Gatz, Margaret

    2014-07-01

    Twin studies are an incomparable source of investigation to shed light on genetic and non-genetic components of neurodegenerative diseases, as Alzheimer's disease (AD). Detailed clinicopathologic correlations using twin longitudinal data and post-mortem examinations are mostly missing. We describe clinical and pathologic findings of seven monozygotic (MZ) and dizygotic (DZ) twin pairs. Our findings show good agreement between clinical and pathologic diagnoses in the majority of the twin pairs, with greater neuropathologic concordance in MZ than DZ twins. Greater neuropathologic concordance was found for β-amyloid than tau pathology within the pairs. ApoE4 was associated with higher β-amyloid and earlier dementia onset, and importantly, higher frequency of other co-occurring brain pathologies, regardless of the zygosity. Dementia onset, dementia duration, difference between twins in age at dementia onset and at death, did not correlate with AD pathology. These clinicopathologic correlations of older identical and fraternal twins support the relevance of genetic factors in AD, but not their sufficiency to determine the pathology, and consequently the disease, even in monozygotic twins. It is the interaction among genetic and non-genetic risks which plays a major role in influencing, or probably determining, the degeneration of those brain circuits associated with pathology and cognitive deficits in AD. PMID:24450926

  11. NOTE: Thrombosis of anastomoses may affect the staging sequence of twin twin transfusion syndrome

    NASA Astrophysics Data System (ADS)

    van den Wijngaard, Jeroen P. H. M.; Ross, Michael G.; van Gemert, Martin J. C.

    2008-03-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twins, which share one single monochorionic placenta. It is caused by placental anastomoses which link the two fetoplacental circulations of the twins and allow a chronic net inter-twin transfusion to develop between the fetuses. Clinical presentation of TTTS manifestations has been classified into five different stages. In this paper, we used our computational model of TTTS and examined the possible differences between chronic and rapidly increasing inter-twin transfusion in the simulated TTTS staging sequence. Our results suggest that rapid alterations in the net inter-twin transfusion, e.g. due to thrombosis of placental anastomoses, may produce a different staging sequence than in TTTS caused by chronic inter-twin transfusion. These results may aid an improved knowledge of TTTS pathophysiology under conditions of a rapidly changing cardiovascular function, and contribute to the planning of optimal intervention under such circumstances. Supported in part by the European Community Euro-twin-2-twin project (JPHMvdW) and by the National Institutes of Health, grant HL40899 (MGR).

  12. Mitochondrial DNA heteroplasmy in diabetes and normal adults: role of acquired and inherited mutational patterns in twins

    PubMed Central

    Avital, Gal; Buchshtav, Mor; Zhidkov, Ilia; Tuval (Feder), Jeanette; Dadon, Sarah; Rubin, Eitan; Glass, Dan; Spector, Timothy D.; Mishmar, Dan

    2012-01-01

    Heteroplasmy, the mixture of mitochondrial genomes (mtDNA), varies among individuals and cells. Heteroplasmy levels alter the penetrance of pathological mtDNA mutations, and the susceptibility to age-related diseases such as Parkinson's disease. Although mitochondrial dysfunction occurs in age-related type 2 diabetes mellitus (T2DM), the involvement of heteroplasmy in diabetes is unclear. We hypothesized that the heteroplasmic mutational (HM) pattern may change in T2DM. To test this, we used next-generation sequencing, i.e. massive parallel sequencing (MPS), along with PCR–cloning–Sanger sequencing to analyze HM in blood and skeletal muscle DNA samples from monozygotic (MZ) twins either concordant or discordant for T2DM. Great variability was identified in the repertoires and amounts of HMs among individuals, with a tendency towards more mutations in skeletal muscle than in blood. Whereas many HMs were unique, many were either shared among twin pairs or among tissues of the same individual, regardless of their prevalence. This suggested a heritable influence on even low abundance HMs. We found no clear differences between T2DM and controls. However, we found ∼5-fold increase of HMs in non-coding sequences implying the influence of negative selection (P < 0.001). This negative selection was evident both in moderate to highly abundant heteroplasmy (>5% of the molecules per sample) and in low abundance heteroplasmy (<5% of the molecules). Although our study found no evidence supporting the involvement of HMs in the etiology of T2DM, the twin study found clear evidence of a heritable influence on the accumulation of HMs as well as the signatures of selection in heteroplasmic mutations. PMID:22736028

  13. Mitochondrial DNA heteroplasmy in diabetes and normal adults: role of acquired and inherited mutational patterns in twins.

    PubMed

    Avital, Gal; Buchshtav, Mor; Zhidkov, Ilia; Tuval Feder, Jeanette; Dadon, Sarah; Rubin, Eitan; Glass, Dan; Spector, Timothy D; Mishmar, Dan

    2012-10-01

    Heteroplasmy, the mixture of mitochondrial genomes (mtDNA), varies among individuals and cells. Heteroplasmy levels alter the penetrance of pathological mtDNA mutations, and the susceptibility to age-related diseases such as Parkinson's disease. Although mitochondrial dysfunction occurs in age-related type 2 diabetes mellitus (T2DM), the involvement of heteroplasmy in diabetes is unclear. We hypothesized that the heteroplasmic mutational (HM) pattern may change in T2DM. To test this, we used next-generation sequencing, i.e. massive parallel sequencing (MPS), along with PCR-cloning-Sanger sequencing to analyze HM in blood and skeletal muscle DNA samples from monozygotic (MZ) twins either concordant or discordant for T2DM. Great variability was identified in the repertoires and amounts of HMs among individuals, with a tendency towards more mutations in skeletal muscle than in blood. Whereas many HMs were unique, many were either shared among twin pairs or among tissues of the same individual, regardless of their prevalence. This suggested a heritable influence on even low abundance HMs. We found no clear differences between T2DM and controls. However, we found ~5-fold increase of HMs in non-coding sequences implying the influence of negative selection (P < 0.001). This negative selection was evident both in moderate to highly abundant heteroplasmy (>5% of the molecules per sample) and in low abundance heteroplasmy (<5% of the molecules). Although our study found no evidence supporting the involvement of HMs in the etiology of T2DM, the twin study found clear evidence of a heritable influence on the accumulation of HMs as well as the signatures of selection in heteroplasmic mutations.

  14. Vasospastic Angina in Identical Twins

    PubMed Central

    Yoshioka, Takayuki; Otsui, Kazunori; Suzuki, Atsushi; Ozawa, Toru; Iwata, Sachiyo; Takei, Asumi; Inoue, Nobutaka

    2015-01-01

    Patient: Male, 58 Final Diagnosis: Vasospastic angina Symptoms: Chest pain Medication: — Clinical Procedure: Medical treatment Specialty: Cardiology Objective: Rare disease Background: The clinical conditions of various diseases, including coronary artery disease, are determined by genetics and the environment. Previous investigations noted the significance of genetic mutations and polymorphisms in cases of coronary spasm. Case Report: We report on monozygotic identical twins who almost simultaneously presented with vasospastic angina. The 58-year-old younger twin was admitted to our hospital because of persistent chest pain. An electrocardiogram showed an inverted T wave in the left precordial leads. Coronary angiographies revealed a short left main trunk (LMT) and 50% stenosis at the proximal portion of the left anterior descending artery (LAD). Infusion of acetylcholine to his left coronary artery caused marked vasoconstriction associated with a sensation of chest oppression. Nitroglycerine completely reversed this response. Based on these findings, we diagnosed Twin A with vasospastic angina. At nearly the same time, his identical twin brother was diagnosed with vasospastic angina at another hospital. Comparison of both coronary angiograms indicated similar structure of coronary vessels, including short LMT and mild stenosis at the proximal portion of LAD. Conclusions: These 2 cases highlight the importance of genetic factors in the pathogenesis of vasospastic angina. It may be important for individuals to receive medical attention if their identical twin presents with vasospastic angina. PMID:26347942

  15. There Is a World outside of Experimental Designs: Using Twins to Investigate Causation

    ERIC Educational Resources Information Center

    Hart, Sara A.; Taylor, Jeanette; Schatschneider, Christopher

    2013-01-01

    This study introduces a co-twin control method commonly used in the medical literature but not often within educational research. This method allows for a comparison of twins discordant for an "exposure," approximating alternative outcomes in the counterfactual model. Example analyses use data drawn from the Florida Twin Project on Reading to…

  16. Head Circumferences in Twins With and Without Autism Spectrum Disorders

    PubMed Central

    Cleveland, Sue; Torres, Andrea; Phillips, Jennifer; Cohen, Brianne; Torigoe, Tiffany; Miller, Janet; Fedele, Angie; Collins, Jack; Smith, Karen; Lotspeich, Linda; Croen, Lisa A.; Ozonoff, Sally; Lajonchere, Clara; Grether, Judith K.; Hallmayer, Joachim

    2013-01-01

    To determine the genetic relationship between head circumference (HC) and Autism Spectrum Disorders (ASDs). Twin pairs with at least one twin with an ASD were assessed. HCs in affected and unaffected individuals were compared, as were HC correlations in monozygotic and dizygotic pairs. 404 subjects, ages 4–18, were included. 20 % of males and 27 % of females with an ASD had macrocephaly. Unaffected co-twins showed similar rates (15 % of males and 22 % of females). Statistical analysis revealed no significant difference in HCs between affected and unaffected twins. Twins with ASDs and unaffected co-twins have similar HCs and increased rates of macrocephaly. Correlations demonstrated partial inheritance of HCs. Thus, macrocephaly may represent an endophenotype in ASDs. PMID:23321801

  17. Twin methodology in epigenetic studies.

    PubMed

    Tan, Qihua; Christiansen, Lene; von Bornemann Hjelmborg, Jacob; Christensen, Kaare

    2015-01-01

    Since the final decades of the last century, twin studies have made a remarkable contribution to the genetics of human complex traits and diseases. With the recent rapid development in modern biotechnology of high-throughput genetic and genomic analyses, twin modelling is expanding from analysis of diseases to molecular phenotypes in functional genomics especially in epigenetics, a thriving field of research that concerns the environmental regulation of gene expression through DNA methylation, histone modification, microRNA and long non-coding RNA expression, etc. The application of the twin method to molecular phenotypes offers new opportunities to study the genetic (nature) and environmental (nurture) contributions to epigenetic regulation of gene activity during developmental, ageing and disease processes. Besides the classical twin model, the case co-twin design using identical twins discordant for a trait or disease is becoming a popular and powerful design for epigenome-wide association study in linking environmental exposure to differential epigenetic regulation and to disease status while controlling for individual genetic make-up. It can be expected that novel uses of twin methods in epigenetic studies are going to help with efficiently unravelling the genetic and environmental basis of epigenomics in human complex diseases. PMID:25568460

  18. Finding the needle in the haystack: differentiating "identical" twins in paternity testing and forensics by ultra-deep next generation sequencing.

    PubMed

    Weber-Lehmann, Jacqueline; Schilling, Elmar; Gradl, Georg; Richter, Daniel C; Wiehler, Jens; Rolf, Burkhard

    2014-03-01

    Monozygotic (MZ) twins are considered being genetically identical, therefore they cannot be differentiated using standard forensic DNA testing. Here we describe how identification of extremely rare mutations by ultra-deep next generation sequencing can solve such cases. We sequenced DNA from sperm samples of two twins and from a blood sample of the child of one twin. Bioinformatics analysis revealed five single nucleotide polymorphisms (SNPs) present in the twin father and the child, but not in the twin uncle. The SNPs were confirmed by classical Sanger sequencing. Our results give experimental evidence for the hypothesis that rare mutations will occur early after the human blastocyst has split into two, the origin of twins, and that such mutations will be carried on into somatic tissue and the germline. The method provides a solution to solve paternity and forensic cases involving monozygotic twins as alleged fathers or originators of DNA traces. PMID:24528578

  19. Quantum discord with weak measurements

    SciTech Connect

    Singh, Uttam Pati, Arun Kumar

    2014-04-15

    Weak measurements cause small change to quantum states, thereby opening up the possibility of new ways of manipulating and controlling quantum systems. We ask, can weak measurements reveal more quantum correlation in a composite quantum state? We prove that the weak measurement induced quantum discord, called as the “super quantum discord”, is always larger than the quantum discord captured by the strong measurement. Moreover, we prove the monotonicity of the super quantum discord as a function of the measurement strength and in the limit of strong projective measurement the super quantum discord becomes the normal quantum discord. We find that unlike the normal discord, for pure entangled states, the super quantum discord can exceed the quantum entanglement. Our results provide new insights on the nature of quantum correlation and suggest that the notion of quantum correlation is not only observer dependent but also depends on how weakly one perturbs the composite system. We illustrate the key results for pure as well as mixed entangled states. -- Highlights: •Introduced the role of weak measurements in quantifying quantum correlation. •We have introduced the notion of the super quantum discord (SQD). •For pure entangled state, we show that the SQD exceeds the entanglement entropy. •This shows that quantum correlation depends not only on observer but also on measurement strength.

  20. Quantum discord and Maxwell's demons

    SciTech Connect

    Zurek, Wojciech Hubert

    2003-01-01

    Quantum discord was proposed as an information-theoretic measure of the 'quantumness' of correlations. I show that discord determines the difference between the efficiency of quantum and classical Maxwell's demons - that is, entities that can or cannot measure nonlocal observables or carry out conditional quantum operations - in extracting work from collections of correlated quantum systems.

  1. Purified discord and multipartite entanglement

    SciTech Connect

    Brown, Eric G.; Webster, Eric J.; Martín-Martínez, Eduardo; Kempf, Achim

    2013-10-15

    We study bipartite quantum discord as a manifestation of a multipartite entanglement structure in the tripartite purified system. In particular, we find that bipartite quantum discord requires the presence of both bipartite and tripartite entanglement in the purification. This allows one to understand the asymmetry of quantum discord, D(A,B)≠D(B,A) in terms of entanglement monogamy. As instructive special cases, we study discord for qubits and Gaussian states in detail. As a result of this we shed new light on a counterintuitive property of Gaussian states: the presence of classical correlations necessarily requires the presence of quantum correlations. Finally, our results also shed new light on a protocol for remote activation of entanglement by a third party. -- Highlights: •Bipartite quantum discord as a manifestation of multipartite entanglement. •Relevance of quantum discord as a utilizable resource for quantum info. tasks. •Quantum discord manifests itself in entanglement in the purified state. •Relation between asymmetry of discord and entanglement monogamy. •Protocol for remote activation of entanglement by a third party.

  2. Use of a twin dataset to identify AMD-related visual patterns controlled by genetic factors

    NASA Astrophysics Data System (ADS)

    Quellec, Gwénolé; Abràmoff, Michael D.; Russell, Stephen R.

    2010-03-01

    The mapping of genotype to the phenotype of age-related macular degeneration (AMD) is expected to improve the diagnosis and treatment of the disease in a near future. In this study, we focused on the first step to discover this mapping: we identified visual patterns related to AMD which seem to be controlled by genetic factors, without explicitly relating them to the genes. For this purpose, we used a dataset of eye fundus photographs from 74 twin pairs, either monozygotic twins, who have the same genotype, or dizygotic twins, whose genes responsible for AMD are less likely to be identical. If we are able to differentiate monozygotic twins from dizygotic twins, based on a given visual pattern, then this pattern is likely to be controlled by genetic factors. The main visible consequence of AMD is the apparition of drusen between the retinal pigment epithelium and Bruch's membrane. We developed two automated drusen detectors based on the wavelet transform: a shape-based detector for hard drusen, and a texture- and color- based detector for soft drusen. Forty visual features were evaluated at the location of the automatically detected drusen. These features characterize the texture, the shape, the color, the spatial distribution, or the amount of drusen. A distance measure between twin pairs was defined for each visual feature; a smaller distance should be measured between monozygotic twins for visual features controlled by genetic factors. The predictions of several visual features (75.7% accuracy) are comparable or better than the predictions of human experts.

  3. Thai Twin Registry: description of the initial stage.

    PubMed

    Nanakorn, Somsong; Chusilp, Kusuma; Kutanan, Wibhu

    2013-02-01

    The present study describes the initial phase of the Thai Twin Registry (TTR) in Khon Kaen University, a pioneer research university located in the Northeast of Thailand. The initial steps of the study included the analysis of dermatoglyphic information in Thai twins for answering the research question: Are monozygotic (MZ) and dizygotic (DZ) twins different in dermatoglyphic variables? Subjects were 212 twin pairs (131 MZ and 81 [corrected] DZ), consisting of 155 males and 269 females. Four types of fingerprint pattern (FP) - that is, arch, radial loop, ulnar loop, and whorl - were classified and analyzed and compared between MZ and DZ twins. The arch radial loop and whorl frequencies differ between MZ and DZ twins. When comparing FP in each finger, only the right little finger shows a statistically different FP, while the FP similarity average from 10 homologous fingers of co-twins was greater in MZ than DZ twins. By using the Area Under the Receiver Operating Characteristic curve analysis, the MZ twins could be differentiated from DZ twins by the FP similarity. Summarizing, this valuable report about TTR was conducted by analysis of FP data, which indicated that the MZ and DZ twins exhibited FP pattern and FP similarity differences. Other dermatoglyphic studies of the existing FP database, such as finger ridge count, finger ridge density, and minutia, will be considered for ongoing research at the TTR.

  4. [Adult twins].

    PubMed

    Charlemaine, Christiane

    2006-12-31

    This paper explores the deep roots of closeness that twins share in their youngest age and their effect on their destiny at the adult age. Psychologists believe the bond between twins begins in utero and develops throughout the twins' lives. The four patterns of twinship described show that the twin bond is determined by the quality of parenting that twins receive in their infancy and early childhood. Common problems of adult twins bring about difficulties to adapt in a non-twin world. The nature versus nurture controversy has taken on new life focusing on inter-twin differences and the importance of parent-child interaction as fundamental to the growth and development of personality. PMID:17352324

  5. Twin anemia polycythemia sequence: a single center experience and literature review.

    PubMed

    Moaddab, Amirhossein; Nassr, Ahmed A; Espinoza, Jimmy; Ruano, Rodrigo; Bateni, Zhoobin H; Shamshirsaz, Amir A; Mandy, George T; Welty, Stephen E; Erfani, Hadi; Popek, Edwina J; Belfort, Michael A; Shamshirsaz, Alireza A

    2016-10-01

    Twin anemia polycythemia sequence (TAPS) is defined by significant intertwin hemoglobin discordance without the amniotic fluid discordance that characterizes twin-twin-transfusion syndrome (TTTS) in monochorionic twin pregnancies. TAPS is an uncommon condition which can either occur spontaneously, or following fetoscopic laser ablation for TTTS. This complication is thought to result from chronic transfusion through very small placental anastomoses; however, the pathogenesis of TAPS remains unknown. Consequently, there is no consensus in the management of TAPS. In this article, three cases of TAPS are described and we review the literature on this uncommon pregnancy complication.

  6. On the Origin of Rheumatoid Arthritis: The Impact of Environment and Genes—A Population Based Twin Study

    PubMed Central

    Svendsen, Anders J.; Kyvik, Kirsten O.; Houen, Gunnar; Junker, Peter; Christensen, Kaare; Christiansen, Lene; Nielsen, Christian; Skytthe, Axel; Hjelmborg, Jacob V.

    2013-01-01

    Background Rheumatoid arthritis (RA) is an autoimmune disease with a complex origin. Previous studies have reported heritability estimates on RA at about 60%. Only 16% of the genetic background of the disease has been disclosed so far. The purpose of the present investigation was to provide an optimized estimate on the heritability of RA and to study the recurrence risk in a nationwide Caucasian twin population. Methods and Findings In a mail survey addressed to 56.707 twin individuals, RA was reported by 479 individuals, mean age 52 (range 16–73). Respondents underwent an interview and clinical examination. Ascertainment probability was 80%. RA was confirmed in 162 twin individuals yielding a prevalence at 0.37% (95% CI 0.31–0.43). The mean discordance time was 19 years (range 0–57). The concordance was 9.1% (95% CI 1.9 to 24.3) in MZ, 6.4% (95% CI 2.1 to 14.3) in DZss. The increased relative risk of attracting RA conditioned on having an affected cotwin compared to the background population risk was 24.6 to 35.4 in MZ twins and 17.3 to 31.6 in DZss twins. The correlation coefficients were 0.60 (0.33 to 0.78) in monozygotic (MZ) and 0.55 (0.33 to 0.72) in dizygotic same sexed (DZss) pairs. Twelve percent (95% CI 0–76%) of the phenotypic variance in the liability to RA was due to additive genetic effects, 50% (95% CI 0–72%) to shared environmental effects and 38% (95% CI 17–61%) to non-shared environmental effects. Conclusions This study emphasizes that family factors are important for the development of RA. Although genetic effectors are important, shared and non-shared environmental triggers and/or epigenetic stochastic events seem to be even more significant. However, it should be borne in mind that the genetic and non-genetic components may not be the same across disease subsets. PMID:23468964

  7. Mirror-image trigger thumb in dichorionic identical twins.

    PubMed

    Wang, Eric D; Xu, Xiaoti; Dagum, Alexander B

    2012-06-01

    The congenital vs acquired etiology of pediatric trigger thumb is the subject of considerable debate. Existing case reports of bilateral presentation in identical twins and first-degree familial association support the congenital hypothesis. However, prospective studies have yet to report a neonate presenting with this anomaly at birth. This article describes the first known set of dichorionic, monozygotic identical twins with unilateral trigger thumbs, affecting contralateral (mirror-image) hands and with asynchronous age at presentation (11 months and 18 months, respectively).Pediatric trigger thumb is caused by a mismatch between the flexor pollicis longus tendon and its A1 synovial pulley. Four sets of twins have been previously reported in the literature with trigger thumb. Of these, 3 sets were monozygotic twins who had bilaterally affected thumbs. Together with the absence of trauma, a congenital etiology was suggested. The fact that pediatric trigger thumb is generally seen several months after birth was felt to be due to infants holding their thumbs clutched in their palms until 6 months. However, no confirmed cases of trigger thumb have been diagnosed at birth in several large prospective studies of newborns.In the current case, the asynchronous presentation of unilateral trigger thumbs in identical twins does not support a solely congenital cause. Furthermore, the mirror-image presentation contradicts current embryological understanding of the temporal course of twinning and the determination of laterality. Thus, a multifactorial etiology is supported with both a genetic and acquired component affecting the development of this condition. PMID:22691680

  8. Genetic and environmental effects on the bone development of the hand and wrist in Chinese young twins.

    PubMed

    Dong, Li Yan; Tan, Ji Bin; Zhao, Jing Lan; Jiang, Fa Chun; Tian, Xiao Cao; Ning, Feng; Wang, Shao Jie; Zhang, Dong Feng; Pang, Zeng Chang; Zhao, Zhong Tang

    2015-03-01

    We assessed genetic and environmental effects on bone development of the hand and wrist, and on key anthropometric measures in Chinese young twins. In total, 139 monozygotic and 95 dizygotic twin pairs aged from 5 to 18 years were recruited. The twin correlations of total hand and wrist scores for monozygotic (MZ) and dizygotic (DZ) twins were 0.71 and 0.36, respectively. Bivariate model analysis showed moderate genetic correlations only for total skeletal maturity vs. weight and total skeletal maturity vs. waist circumference (r, 0.51 and 0.46, respectively). Our findings demonstrated that genetic factors played important roles in bone development of the hand and wrist in Chinese young twins, and that these genetic effects might be distinct from those influencing anthropometric measures. PMID:25800451

  9. Intrapair Similarity of Computer Self-Efficacy in Turkish Adolescent Twins

    ERIC Educational Resources Information Center

    Deryakulu, Deniz; Mcilroy, David; Ursavas, Ömer Faruk; Çaliskan, Erkan

    2016-01-01

    The purpose of this study is to investigate genetic and environmental influences on computer self-efficacy. A total of 165 Turkish twin-pairs participated in the study. Participants' mean age was 12.45 (SD = 1.82). The results of paired t-test comparisons showed no significant differences in monozygotic, and both same-sex and opposite-sex…

  10. Genetic Influences on Perceptions of Childhood Family Environment: A Reared Apart Twin Study.

    ERIC Educational Resources Information Center

    Hur, Yoon-Mi; Bouchard, Thomas J., Jr.

    1995-01-01

    Estimates the extent to which heredity influences perceptions of childhood family environment in a sample of 58 monozygotic and 46 dizygotic pairs of adult twins who were reared apart. The data confirm the importance of genetic factors in some, but not all, measures of family environment. Environmental influences were more important than genetic…

  11. Do Environmental Similarities Explain the Similarity in Intelligence of Identical Twins Reared Apart?

    ERIC Educational Resources Information Center

    Bouchard, Thomas J., Jr.

    1983-01-01

    Taylor (1980) claims to show that the similarity in IQ between monozygotic twins reared apart found in prior studies is due to similarity in their environments. A reanalysis using Taylor's classification of environments but an alternative IQ measure shows that his findings do not constructively replicate. (Author/RD)

  12. Superfecundation and dual paternity in a twin pregnancy ending with placental abruption.

    PubMed

    Ambach, E; Parson, W; Brezinka, C

    2000-01-01

    A case of superfecundation and dual paternity in a twin pregnancy is presented. Placental abruption developed at week 33 of gestation and the two boys had to be saved by emergency cesarean section. As they shared one placenta, had almost identical weight and had the same sex, they were assumed to be monozygotic. However, a subsequent paternity suit led to the conclusion, based on DNA-analysis, that the twin brothers had been fathered by two different men. Obstetrical implications are discussed.

  13. Twin concordance and sibling recurrence rates in multiple sclerosis

    PubMed Central

    Willer, C. J.; Dyment, D. A.; Risch, N. J.; Sadovnick, A. D.; Ebers, G. C.

    2003-01-01

    Size and ascertainment constraints often limit twin studies to concordance comparisons between identical and fraternal twins. Here we report the final results of a longitudinal, population-based study of twins with multiple sclerosis (MS) in Canada. Bias was demonstrably minimized, and an estimated 75% of all Canadian MS twin pairs were ascertained, giving a sample sufficiently large (n = 370) to permit additional informative comparisons. Twinning was not found to affect prevalence, and twins with MS did not differ from nontwins for DR15 allele frequency nor for MS risk to their siblings. Probandwise concordance rates of 25.3% (SE ± 4.4) for monozygotic (MZ), 5.4% (±2.8) for dizygotic (DZ), and 2.9% (±0.6) for their nontwin siblings were found. MZ twin concordance was in excess of DZ twin concordance. The excess concordance in MZ was derived primarily from like-sexed female pairs with a probandwise concordance rate of 34 of 100 (34 ± 5.7%) compared with 3 of 79 (3.8 ± 2.8%) for female DZ pairs. We did not demonstrate an MZ/DZ difference in males, although the sample size was small. We observed a 2-fold increase in risk to DZ twins over nontwin siblings of twins, but the difference was not significant. PMID:14569025

  14. Current twin studies in Germany: report on CoSMoS, SOEP, and ChronoS.

    PubMed

    Hahn, Elisabeth; Gottschling, Juliana; Spinath, Frank M

    2013-02-01

    This article summarizes the status of three recent German twin studies: CoSMoS, SOEP, and ChronoS. The German twin study on Cognitive Ability, Self-Reported Motivation, and School Achievement (CoSMoS) is a three-wave longitudinal study of monozygotic and dizygotic twins reared together, and aims to investigate predictors of and influences on school performance. In the first wave of the data collection in 2005, 408 pairs of twins aged between 7 and 11 as well as their parents participated in CoSMoS. The SOEP twin study is an extended twin study, which has combined data from monozygotic and dizygotic twins reared together with additional data from full sibling pairs, mother-child, and grandparent-child dyads who participated in the German Socio-Economic Panel (GSOEP) study. The SOEP twin project comprises about 350 twin and 950 non-twin pairs aged between 17 and 70. Data were collected between 2009 and 2010, with a focus on personality traits, wellbeing, education, employment, income, living situation, life-satisfaction, and several attitudes. The aim of the Chronotype twin study (ChronoS) was to examine genetic and environmental influences on chronotype (morningness and eveningness), coping strategies, and several aspects of the previous SOEP twin project in a sample of 301 twin pairs aged between 19 and 76 years, recruited in 2010 and 2011. Part of the ChronoS twin sample also participated in the earlier SOEP twin study, representing a second wave of assessments. We briefly describe the design and contents of these three studies as well as selected recent findings.

  15. Imperfect twinning: a clinical and ethical dilemma

    PubMed Central

    Denardin, Daniela; Telles, Jorge Alberto B.; Betat, Rosilene da Silveira; Fell, Paulo Renato K.; da Cunha, André Campos; Targa, Luciano Vieira; Zen, Paulo Ricardo G.; Rosa, Rafael Fabiano M.

    2013-01-01

    OBJECTIVE To review the history, epidemiology, etiology, gestational aspects, diagnosis and prognosis of imperfect twinning. DATA SOURCES Scientific articles were searched in PubMed, SciELO and Lilacs databases, using the descriptors "conjoined twins", "multiple pregnancy", "ultrasound", "magnetic resonance imaging" and "prognosis". The research was not delimited to a specific period of time and was supplemented with bibliographic data from books. DATA SYNTHESIS: The description of conjoined twins is legendary. The estimated frequency is 1/45,000-200,000 births. These twins are monozygotic, monochorionic and usually monoamniotic. They can be classified by the most prominent fusion site, by the symmetry between the conjoined twins or by the sharing structure. The diagnosis can be performed in the prenatal period or after birth by different techniques, such as ultrasound, magnetic resonance imaging and echocardiography. These tests are of paramount importance for understanding the anatomy of both fetuses/children, as well as for prognosis and surgical plan determination. CONCLUSIONS Although imperfect twinning is a rare condition, the prenatal diagnosis is very important in order to evaluate the fusion site and its complexity. Hence, the evaluation of these children should be multidisciplinary, involving mainly obstetricians, pediatricians and pediatric surgeons. However, some decisions may constitute real ethical dilemmas, in which different points should be discussed and analyzed with the health team and the family. PMID:24142323

  16. Genetic and environmental contributions to pro-social attitudes: a twin study of social responsibility.

    PubMed

    Rushton, J Philippe

    2004-12-22

    Although 51 twin and adoption studies have been performed on the genetic architecture of antisocial behaviour, only four previous studies have examined a genetic contribution to pro-social behaviour. Earlier work by the author with the University of London Institute of Psychiatry Adult Twin Register found that genes contributed approximately half of the variance to measures of self-report altruism, empathy, nurturance and aggression, including acts of violence. The present study extends those results by using a 22-item Social Responsibility Questionnaire with 174 pairs of monozygotic twins and 148 pairs of dizygotic twins. Forty-two per cent of the reliable variance was due to the twins' genes, 23% to the twins' common environment and the remainder to the twins' non-shared environment.

  17. Why Accurate Knowledge of Zygosity is Important to Twins.

    PubMed

    Cutler, Tessa L; Murphy, Kate; Hopper, John L; Keogh, Louise A; Dai, Yun; Craig, Jeffrey M

    2015-06-01

    All same-sex dizygotic (DZ) twins and approximately one-third of monozygotic (MZ) twin pairs have separate placentas, making it impossible to use the number of placentas to determine zygosity. Zygosity determination is further complicated because incorrect assumptions are often made, such as that only DZ pairs have two placentas and that all MZ pairs are phenotypically identical. These assumptions, by twins, their families and health professionals, along with the lack of universal zygosity testing for same-sex twins, has led to confusion within the twin community, yet little research has been conducted with twins about their understanding and assumptions about zygosity. We aimed to explore and quantify understanding and assumptions about zygosity using twins attending an Australian twin festival. We recruited 91 twin pairs younger than 18 years of age and their parents, and 30 adult twin pairs who were all uncertain of their zygosity, to complete one pen and paper questionnaire and one online questionnaire about their assumed zygosity, reasons for their assumptions and the importance of accurate zygosity knowledge. Responses were compared with their true zygosity measured using a genetic test. We found a substantial proportion of parents and twins had been misinformed by their own parents or medical professionals, and that knowledge of their true zygosity status provided peace of mind and positive emotional responses. For these reasons we propose universal zygosity testing of same-sex twins as early in life as possible and an increase in education of medical professionals, twins and families of twins about zygosity issues. PMID:25851727

  18. Why Accurate Knowledge of Zygosity is Important to Twins.

    PubMed

    Cutler, Tessa L; Murphy, Kate; Hopper, John L; Keogh, Louise A; Dai, Yun; Craig, Jeffrey M

    2015-06-01

    All same-sex dizygotic (DZ) twins and approximately one-third of monozygotic (MZ) twin pairs have separate placentas, making it impossible to use the number of placentas to determine zygosity. Zygosity determination is further complicated because incorrect assumptions are often made, such as that only DZ pairs have two placentas and that all MZ pairs are phenotypically identical. These assumptions, by twins, their families and health professionals, along with the lack of universal zygosity testing for same-sex twins, has led to confusion within the twin community, yet little research has been conducted with twins about their understanding and assumptions about zygosity. We aimed to explore and quantify understanding and assumptions about zygosity using twins attending an Australian twin festival. We recruited 91 twin pairs younger than 18 years of age and their parents, and 30 adult twin pairs who were all uncertain of their zygosity, to complete one pen and paper questionnaire and one online questionnaire about their assumed zygosity, reasons for their assumptions and the importance of accurate zygosity knowledge. Responses were compared with their true zygosity measured using a genetic test. We found a substantial proportion of parents and twins had been misinformed by their own parents or medical professionals, and that knowledge of their true zygosity status provided peace of mind and positive emotional responses. For these reasons we propose universal zygosity testing of same-sex twins as early in life as possible and an increase in education of medical professionals, twins and families of twins about zygosity issues.

  19. Matching osteochondritis dissecans lesions in identical twin brothers.

    PubMed

    Richie, Lucas B; Sytsma, Mark J

    2013-09-01

    Osteochondritis dissecans is a disorder of unknown etiology that can result in fragmentation of osteochondral surfaces, most commonly of the knee, shoulder, elbow, and ankle. This may lead to sequelae of pain and an inability to participate in desired activities. Multiple theories exist as to the true cause of the disorder, but none have been fully proven. One such proposed etiology is genetic causation. Familial cases of osteochondritis dissecans are rare, yet these cases offer support to growing evidence that may support a genetic link. This article describes osteochondritis dissecans lesions of the femoral trochlea in monozygotic (identical) twins. Both twins presented with similar symptoms 1 year apart. Neither twin had any clear inciting trauma. Magnetic resonance imaging revealed osteochondral lesions in similar positions of the lateral trochlear of the same knee in both brothers. Osteochondral autograft transfer and tibial tubercle anteromedialization were performed on both patients. An identical postoperative protocol was followed, and recovery with full return to sport was comparable for the brothers. To the authors' knowledge, only 1 other case report exists of osteochondritis dissecans lesions in monozygotic twins. Although debate continues regarding the true etiology of this disorder, cases of identical twins presenting with a similar disease process are highly suggestive of a genetic component and may lead to early identification and treatment of these lesions. Continued research in the area of osteochondritis dissecans and its genetic basis is needed to completely understand this disorder. PMID:24025016

  20. The Cuban Twin Registry: initial findings and perspectives.

    PubMed

    Marcheco-Teruel, Beatriz; Cobas-Ruiz, Marcia; Cabrera-Cruz, Niviola; Lantigua-Cruz, Araceli; García-Castillo, Elsa; Lardoeyt-Ferrer, Roberto; Robaina-Jiménez, Zoe; Fuentes-Smith, Evelyn; Morales-Calatayud, Francisco; Lemus-Valdés, María Teresa; Portuondo-Sao, Miriam; Comas-Pérez, Lenier; Pérez-Crispí, Juan M; Díaz-De Villal Villa, Thais; Icart-Perera, Emelia; Jordán-Hernández, Aida; Lage-Castellanos, Agustín; Rabell-Piera, Sergio; Llibre-Rodríguez, Juan de Jesús; Valdés-Sosa, Pedro; Valdés-Sosa, Mitchell

    2013-02-01

    The Cuban Twin Registry is a nation-wide, prospective, population-based twin registry comprising all zygosity types and ages. It was initiated in 2004 to study genetic and environmental contributions to complex diseases with high morbidity and mortality in the Cuban population. The database contains extensive information from 55,400 twin pairs enrolled in the period 2004-2006. Additionally, 2,600 new multiple births have been included from 2007 to date. In the past 4 years, more than 130 studies have been carried out using the registry with a classical genetic epidemiological approach in which concordance rates for monozygotic and dizygotic twins and heritability of various disease traits were estimated. This article summarizes the history, registry's methodology, recent research findings, and future directions of work. PMID:23228217

  1. SuperQuads: a day in the life; research reviews: color-number association, finger-length ratios, twinning diets, athletic pairs.

    PubMed

    Segal, Nancy L

    2006-08-01

    The nature and frequency of quadruplet births are reviewed, followed by a close-up look at the 6-year-old monozygotic Mathias quadruplets. This essay is followed by reviews of new twin research on color-number association, male-female twins' finger-length ratios, and links between twinning and dietary practices. The article finishes by focusing on unusual twin athletes in football, basketball and golf, and on twin co-authors of a new book on the 1972 silver medal victory by the United States hockey team.

  2. How Do Friends Influence Smoking Uptake? Findings from Qualitative Interviews with Identical Twins

    ERIC Educational Resources Information Center

    McLeod, Kim; White, Victoria; Mullins, Robyn; Davey, Claire; Wakefield, Melanie; Hill, David

    2008-01-01

    The smoking behavior of friends is a major risk factor for adolescent smoking uptake. To explore the social context of smoking experimentation and consolidation with a particular focus on friends, the authors interviewed both members of 14 young adult identical twin pairs who were discordant for smoking. The different smoking status of twins was…

  3. Attentional Regulation in Young Twins with Probable Stuttering, High Nonfluency, and Typical Fluency

    ERIC Educational Resources Information Center

    Felsenfeld, Susan; van Beljsterveldt, Catharina Eugenie Maria; Boomsma, Dorret Irene

    2010-01-01

    Purpose: Using a sample of 20,445 Dutch twins, this study examined the relationship between speech fluency and attentional regulation in children. A secondary objective was to identify etiological overlap between nonfluency and poor attention using fluency-discordant twin pairs. Method: Three fluency groups were created at age 5 using a parent…

  4. The Twin Research Registry at SRI International.

    PubMed

    Krasnow, Ruth E; Jack, Lisa M; Lessov-Schlaggar, Christina N; Bergen, Andrew W; Swan, Gary E

    2013-02-01

    The Twin Research Registry (TRR) at SRI International is a community-based registry of twins established in 1995 by advertising in local media, mainly on radio stations and in newspapers. As of August 2012, there are 3,120 same- and opposite-sex twins enrolled; 86% are 18 years of age or older (mean age 44.9 years, SD 16.9 years) and 14% less than 18 years of age (mean age 8.9 years, SD 4.5); 67% are female, and 62% are self-reported monozygotic (MZ). More than 1,375 twins have participated in studies over the last 15 years in collaboration with the University of California Medical Center in San Francisco, the University of Texas MD Anderson Cancer Center, and the Stanford University School of Medicine. Each twin completes a registration form with basic demographic information either online at the TRR Web site or during a telephone interview. Contact is maintained with members by means of annual newsletters and birthday cards. The managers of the TRR protect the confidentiality of twin data with established policies; no information is given to other researchers without prior permission from the twins; and all methods and procedures are reviewed by an Institutional Review Board. Phenotypes studied thus far include those related to nicotine metabolism, mutagen sensitivity, pain response before and after administration of an opioid, and a variety of immunological responses to environmental exposures, including second-hand smoke and vaccination for seasonal influenza virus and Varicella zoster virus. Twins in the TRR have participated in studies of complex, clinically relevant phenotypes that would not be feasible to measure in larger samples. PMID:23084148

  5. Reflectance spectrometry of placental vessels in cases of twin-twin transfusion syndrome: experiments and modeling

    NASA Astrophysics Data System (ADS)

    Lines, Collin; Kim, Oleg; McMurdy, John; Luks, Francois; Alber, Mark; Crawford, Greg

    2013-03-01

    A stochastic photon transport model in multilayer skin tissue combined with reflectance spectroscopy measurements is used to study placental vessels in cases of twin-twin transfusion syndrome (TTTS). TTTS occurs in about 12% of monozygotic (identical) twin pregnancies wherein flow within placental vessels linking the twins together becomes unbalanced, leading to dual mortality. Endoscopic laser ablation can halt the syndrome by occluding the anastomoses connecting the two fetuses. The objective of this study is to develop a technique to determine hemoglobin (Hb) content through spectral analysis of diffuse reflectance spectra of placental vessels to aid in identification of the anastomoses. Previous work by researchers at Brown University has shown that the reflectance spectra of the donor twin and recipient twin are considerably different in the wavelengths for Hb absorbance. This presentation will give preliminary results for a Monte Carlo model adapted to fit the physiology of the placenta that can be used to quantitative determine the Hb levels. The reflectance spectra of the vessels are simulated for different values of Hb as well oxygenation and water concentration with the vessel and placental mass. The preliminary results will be shown to be in good approximation with the prior experimental data. The combination of modeling with spectroscopic measurement will provide a new tool for detailed prenatal study.

  6. Nature versus nurture in ventral visual cortex: a functional magnetic resonance imaging study of twins.

    PubMed

    Polk, Thad A; Park, Joonkoo; Smith, Mason R; Park, Denise C

    2007-12-19

    Using functional magnetic resonance imaging, we estimated neural activity in twins to study genetic influences on the cortical response to categories of visual stimuli (faces, places, and pseudowords) that are known to elicit distinct patterns of activity in ventral visual cortex. The neural activity patterns in monozygotic twins were significantly more similar than in dizygotic twins for the face and place stimuli, but there was no effect of zygosity for pseudowords (or chairs, a control category). These results demonstrate that genetics play a significant role in determining the cortical response to faces and places, but play a significantly smaller role (if any) in the response to orthographic stimuli. PMID:18094229

  7. Quantum discord, local operations, and Maxwell's demons

    SciTech Connect

    Brodutch, Aharon; Terno, Daniel R.

    2010-06-15

    Quantum discord was proposed as a measure of the quantumness of correlations. There are at least three different discordlike quantities, two of which determine the difference between the efficiencies of a Szilard's engine under different sets of restrictions. The three discord measures vanish simultaneously. We introduce an easy way to test for zero discord, relate it to the Cerf-Adami conditional entropy and show that there is no simple relation between the discord and the local distinguishability.

  8. Mesial temporal lobe epilepsy with hippocampal sclerosis in two pairs of identical twins.

    PubMed

    Karatas, H; Dericioglu, N; Saygi, S

    2012-01-01

    The most common pathology in adult patients with temporal lobe epilepsy is hippocampal sclerosis (HS), the etiology of which is not clear. There is a conflicting evidence in literature regarding whether HS is genetic or acquired. Twin studies can help to clarify the mechanisms of HS, but limited numbers of twins have been studied. We describe two monozygotic pairs, in whom the affected twin had mesial temporal lobe epilepsy and HS. The unaffected twin remained seizure free on long-term follow-up. HS was confirmed pathologically in one of the affected twins. Our data and other limited twin studies indicate that HS occurs as a consequence of prolonged repeated seizures or other events during childhood. In other words, some acquired factors may be more important than genetic ones in the etiology of HS (Fig. 2, Ref. 16). PMID:22794520

  9. Francis Galton on twins, heredity and social class.

    PubMed

    Burbridge, D

    2001-09-01

    In 1875 Francis Galton was the first to study twins as a test of the relative strenght of heredity and environment. This paper examines Galton's work on twins, using his surviving working papers. It shows that his enquiry was larger and more systematic than previously realized. Galton issued several hundred questionnaires to parents of twins, with the aim of establishing how far the similarities and differences between twins were affected by their life experiences. The paper also discusses Galton's study in relation to his understanding of the physiology of twinning and his theory of heredity. The modern concept of monozygotic twins had not yet been established, and the similarity between Galton's work and modern twin studies should not be overstated. While Galton's work was important as a pioneering study, in some respects his conclusions went beyond his evidence. The paper finally examines whether Galton's twin studies influenced his position on the links between social class, heredity and social mobility, and surveys the evidence for his views on these issues. PMID:11700679

  10. DNA methylation studies using twins: what are they telling us?

    PubMed

    Bell, Jordana T; Spector, Tim D

    2012-01-01

    Recent studies have identified both heritable DNA methylation effects and differential methylation in disease-discordant identical twins. Larger sample sizes, replication, genetic-epigenetic analyses and longitudinal assays are now needed to establish the role of epigenetic variants in disease. PMID:23078798

  11. Quantum discord protection from amplitude damping decoherence.

    PubMed

    Yune, Jiwon; Hong, Kang-Hee; Lim, Hyang-Tag; Lee, Jong-Chan; Kwon, Osung; Han, Sang-Wook; Kim, Yong-Su; Moon, Sung; Kim, Yoon-Ho

    2015-10-01

    Entanglement is known to be an essential resource for many quantum information processes. However, it is now known that some quantum features may be acheived with quantum discord, a generalized measure of quantum correlation. In this paper, we study how quantum discord, or more specifically, the measures of entropic discord and geometric discord are affected by the influence of amplitude damping decoherence. We also show that a protocol deploying weak measurement and quantum measurement reversal can effectively protect quantum discord from amplitude damping decoherence, enabling to distribute quantum correlation between two remote parties in a noisy environment. PMID:26480116

  12. Non-Markovian dynamics of quantum discord

    SciTech Connect

    Fanchini, F. F.; Caldeira, A. O.; Werlang, T.; Brasil, C. A.; Arruda, L. G. E.

    2010-05-15

    We evaluate the quantum discord dynamics of two qubits in independent and common non-Markovian environments. We compare the dynamics of entanglement with that of quantum discord. For independent reservoirs the quantum discord vanishes only at discrete instants whereas the entanglement can disappear during a finite time interval. For a common reservoir, quantum discord and entanglement can behave very differently with sudden birth of the former but not of the latter. Furthermore, in this case the quantum discord dynamics presents sudden changes in the derivative of its time evolution which is evidenced by the presence of kinks in its behavior at discrete instants of time.

  13. Digital dermatoglyphic heritability differences as evidenced by a female twin study.

    PubMed

    Machado, João Felipe; Fernandes, Paula Roquetti; Roquetti, Ricardo Wagner; Filho, José Fernandes

    2010-10-01

    The genetic and environmental contributions to determine digital dermatoglyphic traits were investigated by using female dizygotic and monozygotic twin pairs to estimate heritability indexes (h(2)). The evaluated sample was composed by 20 monozygotic twin pairs and 13 dizygotic twin pairs. A significant heritability (h(2) = 0.65 to 0.96) was observed for 12 dermatoglyphic characteristics (delta indexes and ridge counts for right hand, left hand and both hands, and ridge counts for most individual fingers). A negative correlation between the ridge counts and heritability indexes from individual fingers was found for the left hand, which appears to be associated to a higher arch pattern frequency in most left-hand fingers, since this frequency was negatively correlated with ridge counts and positively correlated with heritability indexes. Heritability indexes of right-hand fingers were positively correlated with loop pattern frequency and negatively correlated with whorl pattern frequency. The low heritability of ridge counts from left thumb, ring and little fingers (h(2) = 0.11 to 0.32) indicates a higher chance that the chorion type had an influence in the intra-pair variance of monozygotic twins. Results confirmed the predominant genetic influence on the total ridge count. The heritability indexes varied in up to 8 times between different fingers and its association to ridge counts and pattern frequency was very variable between hands, evidencing that the use of dermatoglyphic traits from individual fingers as indicators of genetic influences to other human traits should consider this variability.

  14. Further possible physiological connectedness between identical twins: the London study.

    PubMed

    Parker, Adrian; Jensen, Christian

    2013-01-01

    Four pairs of monozygotic twins were tested for synchronous responses that occurred in the physiological data of one twin during the period when the other twin was exposed to shock and surprise stimuli. Each of the five stimuli was presented in random order, producing five blocks of trial periods within each 25-minute session per twin. There were eight possible trial periods within each block. The choice of the trial periods, that is, the exact time placement of the shock stimuli within the blocks, was determined randomly. Data from six sessions with the four pairs of twins were used by the same polygraph expert who was successful in a previous study in identifying these trial periods. In accordance with the previously determined protocol for the experiment, six of these trials were passed on, leaving 24 trial blocks for which assessments were made as to which period the stimulus had occurred. Six of these gave hits, whereas three hits were expected by chance and four of these six correct placements were made by one of the pairs of twins. The data provide further justification for a major study in this area using the outlined methodology with selected pairs of twins. PMID:23294817

  15. Association between birth weight and neuromotor performance: a twin study.

    PubMed

    Lopes, A A T; Tani, G; Katzmarzyk, P T; Thomis, M A; Maia, J A R

    2014-06-01

    Studies have shown important associations between low birth weight (BW), a variety of morbidities, and reduced motor performance. Using a twin sample, this study aimed to verify (a) the magnitude of the association between BW and neuromotor performance (NMP); (b) if the NMP of twins is within the normal range; and (c) if monozygotic (MZ) and dizygotic (DZ) twins' intra-pair similarities in NMP are of equal magnitude. We sampled 191 twins (78 MZ; 113 DZ distinguished through their DNA), aged 8.9 ± 3.1 years with an average BW of 2246.3 ± 485.4 g; gestational characteristics and sports practices were also assessed. The Zurich Neuromotor test battery, comprising five main tasks, was used; Twins NMP assessments were highly reliable (intra-rater reliability: 0.76-0.99). BW accounted for up to 11% of the total variance of NMP across the zygosity groups. Between 32.7% and 76.9% of children were below the 10th percentile for tasks requiring timing of performance (purely motor task, adaptive fine motor task, dynamic, and static balance), while less than 6.4% of children were below the 10th percentile for associated movements. MZ twins NMP intraclass correlations showed greater similarity than DZ twins in three of the five tasks, suggesting the importance of genetic factors in NMP.

  16. NOTE: Arterio-venous flow between monochorionic twins determined during intra-uterine transfusion

    NASA Astrophysics Data System (ADS)

    van Gemert, Martin J. C.; van den Wijngaard, Jeroen P. H. M.; Lopriore, Enrico; Pasman, Suzanne A.; Vandenbussche, Frank P. H. A.

    2008-04-01

    Twin-twin transfusion syndrome (TTTS) is a severe complication of monozygotic (identical) twin fetuses sharing one single (monochorionic) placenta. TTTS is caused by a net inter-twin transfusion of blood through placental anastomoses, from one twin (the donor) to the other (the recipient), which link the two feto-placental circulations. Currently, the only reliable method to measure the net inter-twin transfusion clinically is when incomplete laser therapy of TTTS occurs and one of the twins becomes anemic and requires an intra-uterine transfusion of adult red blood cells. Then, differences between adult hemoglobin concentrations measured during the transfusion and at birth relate not only to the net inter-twin transfusion but also to the finite lifetime of the adult red blood cells. We have analyzed this situation, derived the differential equations of adult hemoglobin in the donor and recipient twins, given the solutions and given expressions relating the net inter-twin flow with clinically measured parameters. We have included single and multiple intra-uterine transfusions. In conclusion, because incomplete laser therapy occurs frequently, and some cases require an intra-uterine transfusion, this method may allow collecting a wealth of net inter-twin flow data from clinicians involved in laser therapy of TTTS. To aid to the widespread use of this method, we have presented the equations as clearly as possible in tables for easy use by others.

  17. Non-commutativity measure of quantum discord

    NASA Astrophysics Data System (ADS)

    Guo, Yu

    2016-04-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord.

  18. Non-commutativity measure of quantum discord

    PubMed Central

    Guo, Yu

    2016-01-01

    Quantum discord is a manifestation of quantum correlations due to non-commutativity rather than entanglement. Two measures of quantum discord by the amount of non-commutativity via the trace norm and the Hilbert-Schmidt norm respectively are proposed in this paper. These two measures can be calculated easily for any state with arbitrary dimension. It is shown by several examples that these measures can reflect the amount of the original quantum discord. PMID:27122226

  19. Posterior Ankle Impingement in Two Athletic Twin Brothers, Could Genetics Play a Role?

    PubMed

    Bech, Niels H; de Leeuw, Peter A J; Haverkamp, Daniel

    2016-01-01

    Pain posteriorly in the ankle can be caused by bony impingement of the posterolateral process of the talus. This process impinges between the tibia and calcaneus during deep forced plantar flexion. If this occurs it is called posterior ankle impingement syndrome. We report the case of 2 athletic monozygotic twin brothers with bony impingement posteriorly in the left ankle. Treatment consisted of ankle arthroscopy in both patients during which the symptomatic process was easily removed. At 3 months after surgery, both patients were completely free of pain, and 1 of the brothers had already returned to sports. The posterior ankle impingement syndrome is not a rare syndrome, but it has not been described in siblings thus far. That these 2 patients are monozygotic twin brothers suggests that genetics could play a role in the development of skeletal deformities that can result in posterior ankle impingement syndrome.

  20. Genetic and Environmental Influences on Two Measures of Speed of Information Processing and Their Relation to Psychometric Intelligence: Evidence from the German Observational Study of Adult Twins.

    ERIC Educational Resources Information Center

    Neubauer, Alioscha C.; Spinath, Frank M.; Riemann, Rainer; Angleitner, Alois; Borkenau, Peter

    2000-01-01

    Administered 2 elementary cognitive task (ECT) tests and 2 psychometric intelligence tests to 169 monozygotic and 131 dizygotic pairs of twins in Germany. Reaction times correlated negatively with psychometric intelligence, and habitability estimates were substantial for both psychometric intelligence and reaction times on the ECTs. Multivariate…

  1. Geometric quantum discord under noisy environment

    NASA Astrophysics Data System (ADS)

    Huang, Zhiming; Qiu, Daowen

    2016-05-01

    In this work, we mainly analyze the dynamics of geometric quantum discord under a common dissipating environment. Our results indicate that geometric quantum discord is generated when the initial state is a product state. The geometric quantum discord increases from zero to a stable value with the increasing time, and the variations of stable values depend on the system size. For different initial product states, geometric quantum discord has some different behaviors in contrast with entanglement. For initial maximally entangled state, it is shown that geometric quantum discord decays with the increasing dissipated time. It is found that for EPR state, entanglement is more robust than geometric quantum discord, which is a sharp contrast to the existing result that quantum discord is more robust than entanglement in noisy environments. However, for GHZ state and W state, geometric quantum discord is more stable than entanglement. By the comparison of quantum discord and entanglement, we find that a common dissipating environment brings complicated effects on quantum correlation, which may deepen our understanding of physical impacts of decohering environment on quantum correlation. In the end, we analyze the effects of collective dephasing noise and rotating noise to a class of two-qubit X states, and we find that quantum correlation is not altered by the collective noises.

  2. Genetic determinants of bone mass in adults. A twin study.

    PubMed Central

    Pocock, N A; Eisman, J A; Hopper, J L; Yeates, M G; Sambrook, P N; Eberl, S

    1987-01-01

    The relative importance of genetic factors in determining bone mass in different parts of the skeleton is poorly understood. Lumbar spine and proximal femur bone mineral density and forearm bone mineral content were measured by photon absorptiometry in 38 monozygotic and 27 dizygotic twin pairs. Bone mineral density was significantly more highly correlated in monozygotic than in dizygotic twins for the spine and proximal femur and in the forearm of premenopausal twin pairs, which is consistent with significant genetic contributions to bone mass at all these sites. The lesser genetic contribution to proximal femur and distal forearm bone mass compared with the spine suggests that environmental factors are of greater importance in the aetiology of osteopenia of the hip and wrist. This is the first demonstration of a genetic contribution to bone mass of the spine and proximal femur in adults and confirms similar findings of the forearm. Furthermore, bivariate analysis suggested that a single gene or set of genes determines bone mass at all sites. PMID:3624485

  3. Associations Between Sibling Relationship Quality and Friendship Quality in Early Adolescence: Looking at the Case of Twins.

    PubMed

    Bekkhus, Mona; Brendgen, Mara; Czajkowski, Nikolai O; Vitaro, Frank; Dionne, Ginette; Boivin, Michel

    2016-04-01

    Bidirectional pathways between twin relationship quality and friendship quality were investigated in a large longitudinal twin cohort. We examined negative and positive relationship features in 313 monozygotic (MZ) twins and 238 same-sex dizygotic (DZ) twins from ages 13 to 14 years, using latent structural modeling. Results showed stronger stability of the twin relationship quality compared to friendship quality. Positive features in the sibling relationship were associated with increased positive features in the relationship with the best friend a year later. In contrast, no significant association between negative sibling relationship features and change in negative friendship quality features was found. These findings speak to the important role of the sibling relationship in the development of good quality friendship relations in twins. PMID:26952576

  4. Intravenous iron administration together with parenteral nutrition to very preterm Jehovah's Witness twins

    PubMed Central

    Poorisrisak, Porntiva; Schroeder, Allan Mikael; Greisen, Gorm; Zachariassen, Gitte

    2014-01-01

    Preterm twin sisters (monozygotic) were born at gestational age 27 weeks and 5 days with birth weights of 935 and 735 g. They were admitted to our neonatal intensive care unit for a period of 1 month. Their parents were Jehovah’s Witnesses and refused blood transfusion for their preterm daughters. Subcutaneous erythropoietin and intravenous iron were given as a prophylactic to avoid anaemia. PMID:24891477

  5. Twin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project.

    PubMed

    Yokoyama, Yoshie; Jelenkovic, Aline; Sund, Reijo; Sung, Joohon; Hopper, John L; Ooki, Syuichi; Heikkilä, Kauko; Aaltonen, Sari; Tarnoki, Adam D; Tarnoki, David L; Willemsen, Gonneke; Bartels, Meike; van Beijsterveldt, Toos C E M; Saudino, Kimberly J; Cutler, Tessa L; Nelson, Tracy L; Whitfield, Keith E; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; He, Mingguang; Ding, Xiaohu; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Jeong, Hoe-Uk; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Burt, S Alexandra; Klump, Kelly L; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Harris, Jennifer R; Brandt, Ingunn; Nilsen, Thomas Sevenius; Craig, Jeffrey M; Saffery, Richard; Ji, Fuling; Ning, Feng; Pang, Zengchang; Dubois, Lise; Boivin, Michel; Brendgen, Mara; Dionne, Ginette; Vitaro, Frank; Martin, Nicholas G; Medland, Sarah E; Montgomery, Grant W; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Tynelius, Per; Haworth, Claire M A; Plomin, Robert; Rebato, Esther; Rose, Richard J; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Sørensen, Thorkild I A; Boomsma, Dorret I; Kaprio, Jaakko; Silventoinen, Karri

    2016-04-01

    We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI. PMID:26996222

  6. Unicameral Bone Cyst in the Calcaneus of Mirror Image Twins.

    PubMed

    Lenze, Ulrich; Stolberg-Stolberg, Josef; Pohlig, Florian; Lenze, Florian; von Eisenhart-Rothe, Rüdiger; Rechl, Hans; Toepfer, Andreas

    2015-01-01

    Unicameral bone cysts (UBCs) are benign tumor-like lesions that commonly occur in the diaphyseal or metaphyseal region of the long bones within the first 2 decades of life. Until today, the pathogenesis of UBC has been unclear, but mechanisms such as vascular occlusion or a response to trauma have been supposed. During the past decade, in particular, the genetic aspects of the development of this rare lesion have been discussed. We present the first case of mirror image monozygotic twins with a mirror image UBC of the calcaneus. Our findings reinforce the importance of additional studies to understand the significance of cytogenetic factors in the etiology of UBC.

  7. A twin-case study of developmental number sense impairment.

    PubMed

    Davidse, Neeltje J; de Jong, Maria T; Shaul, Shelley; Bus, Adriana G

    2014-01-01

    The current study reports on 9-year-old monozygotic twin girls who fail to make any progress in learning basic mathematics in primary education. We tested the hypothesis that the twins' core maths problems were deficits in number sense that manifested as impairments in approximate and small number systems, resulting in impairment in nonsymbolic as well as in symbolic processing. While age-matched controls (eight typically developing girls) scored highly, the twins scored at chance on all number sense tasks. More specifically, on a nonsymbolic comparison task, even in the simplest ratio condition of 1:2, and on a subitizing task including only numbers under 4, the twins performed at chance and significantly below the same age control group. Responsiveness to an intervention promoting number sense is discussed. As differences between verbal and performance IQ suggest, there seems to be a high degree of specificity in the twins' developmental number sense delays. The concomitant impairments for visual-spatial processing and working memory in the twins might explain the failure to develop number sense.

  8. The Host Genotype and Environment Affect Strain Types of Bifidobacterium longum subsp. longum Inhabiting the Intestinal Tracts of Twins

    PubMed Central

    Zhang, Min; Hang, Xiaomin; Tan, Jing

    2015-01-01

    To investigate the influences of host genotype and environment on Bifidobacterium longum subsp. longum inhabiting human intestines at the strain level, six pairs of twins, divided into two groups (children and adults), were recruited. Each group consisted of two monozygotic (MZ) twin pairs and one dizygotic (DZ) twin pair. Child twins had been living together from birth, while adult twins had been living separately for 5 to 10 years. A total of 345 B. longum subsp. longum isolates obtained from 60 fecal samples from these twins were analyzed by multilocus sequence typing (MLST), and 35 sequence types (STs) were finally acquired. Comparison of strains within and between the twin pairs showed that no strains with identical STs were observed between unrelated individuals or within adult DZ twin pairs. Eight STs were found to be monophyletic, existing within MZ twins and child DZ twins. The similarity of strain types within child cotwins was significantly higher than that within adult cotwins, which indicated that environment was one of the important determinants in B. longum subsp. longum strain types inhabiting human intestines. However, although these differences between MZ and DZ twins were observed, it is still difficult to reach an exact conclusion about the impact of host genotype. This is mainly because of the limited number of subjects tested in the present study and the lack of strain types tracing in the same twin pairs from birth until adulthood. PMID:25956768

  9. Treatment responses to tooth whitening in twins.

    PubMed

    Corby, Patricia M A; Biesbrock, Aaron; Gerlach, Robert; Corby, Andrea L; Moreira, Alexandre; Schork, Nicholas J; Bretz, Walter A

    2014-02-01

    The aim of this study was to determine heritability estimates of treatment responses to a 10% hydrogen peroxide strip-based whitening system in twins. Eighty-five twin pairs were randomly assigned to 10% hydrogen peroxide whitening strips or placebo strips without peroxide. Both twins (monozygotic or dizygotic) received the same treatment. Maxillary teeth were treated for 30 minutes twice daily for 7 days. Efficacy was measured objectively as L* (light-dark), a* (red-green), and b* (yellow-blue) color change from digital images at baseline (∆) and day 8. Heritability estimates for tooth whitening treatment responses for changes from day 8 to baseline were obtained using variance-component methodologies. Whitening treatment responses were highly heritable (h(2) = 71.0) for ∆b* and ∆a*(p < .0001), but not for ∆L* (h(2) = 27.0), which was essentially modulated by environmental factors. This study has demonstrated that both genetic and environmental factors significantly contributed to seven-day whitening treatment responses achieved with 10% hydrogen peroxide strips.

  10. Teacher-Student Discordance and Teacher Recommendations.

    ERIC Educational Resources Information Center

    Johnson, G. M.; Johnson, J. A.

    1991-01-01

    The study calculated "teacher student discordance" for 12 grade 1 teachers and 45 at-risk students. At the end of the school year, students were divided into three groups (positive, neutral, negative) based on teacher recommendations regarding placement. In general, T-S Discordance did not discriminate across teacher recommendation groups. (DB)

  11. The role of the placenta in variability of fetal exposure to cocaine and cannabinoids: a twin study.

    PubMed

    Boskovic, R; Klein, J; Woodland, C; Karaskov, T; Koren, G

    2001-11-01

    There is wide variability in the reported adverse fetal effects of cocaine and cannabinoids. The causes of this variability are largely unknown. We hypothesized that variability in placental handling of drugs affect fetal exposure. We used twin pregnancies as a paradigm to address the role of the placenta in this variability. We analyzed hair or meconium samples taken from dizygotic and monozygotic twins exposed in utero to illicit drugs. Out of 12 pairs, 5 had negative levels in both twins, and seven pairs of twins had chemical evidence of fetal exposure to cocaine (n = 5) or cannabinoids (n = 2). The one known monozygotic pair of twins had almost identical levels of cocaine. In contrast, the six dizygotic pairs had large disparities in either cocaine or cannabinoid concentrations. In three of these six dizygotic pairs, levels of cocaine (n = 2) or canabinoids (n = 1) were undetectable in one twin while positive in the other. Given that twins are theoretically exposed to similar maternal drug levels, our findings suggest that the placenta may have a major role in modulating the amounts of drug reaching the fetus.

  12. Familial factors in early deaths: twins followed 30 years to ages 51-61 in 1978.

    PubMed

    Hrubec, Z; Neel, J V

    1981-01-01

    Subjects in the National Academy of Sciences-National Research Council Twin Registry of 31,848 male twin veterans were followed for mortality from 1 January 1946, or from the date of entry into military service if that was later, to 31 December 1978. During this time 3,573 deaths occurred among them, 837 due to trauma and 2,712 due to disease. Mortality from all causes for the entire follow-up period was 10.2% among 11,350 monozygotic (MZ) twins and 11.4% among 14,450 dizygotic (DZ) twins. Mortality of veterans is known to be favorable compared to U.S. males. Among U.S. males of the same ages as the two respective twin zygosity groups, a mortality of 13.9% would have been expected during this time period. Observed mortality from trauma was 2.3% for MZ twins and 2.5% for DZ twins, with 3.0% expected in either group. Observed mortality from all disease was 7.9% for MZ twins and 8.8% for DZ twins, with 10.9% expected in either group. For total mortality, the case twin concordance rates, based on individual deaths, were 28.2% among MZ twins and 17.7% among DZ twins. For trauma, respectively by zygosity, these concordance rates were 6.9% and 3.9%. In this sample, familial factors appear to be of little consequence in trauma deaths. For all disease the concordance rates were 30.1% and 17.4%. Estimating heritability of liability to death from disease, as proposed by Edwards (1969), provides values of h2 = r = 0.51 for MZ twins, h2 = 2r = 0.48 for DZ twins, and h2 = 2(rMZ-rDZ) = 0.54 using data for the two zygosity groups combined. PMID:10819020

  13. Angiographic studies of atrioventricular discordance.

    PubMed

    Attie, F; Soni, J; Ovseyevitz, J; Muñoz-Castellanos, L; Testelli, M R; Buendia, A

    1980-08-01

    The results and value of conventional and axial angiocardiography were studied in 26 cases of atrioventricular discordance (AVD). The angiographic anatomy of this malformation was analyzed to determine the precise characteristics of atrioventricular and ventriculoarterial connections. The left and right ventricles in atrial situs solitus and levocardia show angiographic features that differ from those seen in atrial situs solitus and dextrocardia. The same differences are found in atrial situs inversus. Regardless of the type of ventriculoarterial connections, the ventricles maintain the same angiographic characteristics. The ventricular septum in AVD in situs solitus and levocardia and situs inversus and dextrocardia has a peculiar orientation. The use of axial angiocardiography facilitates detection and localization of the ventricular septal defect. In cases of malposition of the heart, the conventional frontal view allows visualization of the ventricular septum in all of its length. The axial projection is useful in diagnosing left ventricular outflow tract obstruction.

  14. Testing the equal environments assumption in the Children of Twins design.

    PubMed

    Koenig, Laura B; Jacob, Theodore; Haber, Jon Randolph; Xian, Hong

    2010-07-01

    In a Children of Twins (COT) design, the environmental and genetic risk of a child is, in part, dependent upon the status of the father and the father's cotwin. The logic of the COT method breaks down if the zygosity of the twin pair is confounded with the environment provided to the child (a version of the Equal Environment Assumption, EEA). If MZ twin fathers see each other more often than DZ twin fathers, and a child's uncle is the affected twin in discordant pairs, this could increase the environmental risk of children of MZ over that of DZ discordant twins. The current study was designed to test the EEA in the COT design, specifically in children of alcohol and drug dependent fathers. Results indicated that MZ twins did have more contact than DZ twins. Regression analyses were conducted to predict child externalizing symptom counts from father's zygosity group status, level of contact with father's cotwin, and their interaction. Results found no significant interaction between father's zygosity and the higher level of cotwin contact (seen in MZ twins) in predicting several measures of offspring externalizing risk. The results of this study suggested that the COT design does not confound zygosity with differences in environmental risk exposure, findings that support the validity of the EEA within this research context.

  15. Paternal age and telomere length in twins: the germ stem cell selection paradigm.

    PubMed

    Hjelmborg, Jacob B; Dalgård, Christine; Mangino, Massimo; Spector, Tim D; Halekoh, Ulrich; Möller, Sören; Kimura, Masayuki; Horvath, Kent; Kark, Jeremy D; Christensen, Kaare; Kyvik, Kirsten O; Aviv, Abraham

    2015-08-01

    Telomere length, a highly heritable trait, is longer in offspring of older fathers. This perplexing feature has been attributed to the longer telomeres in sperm of older men and it might be an 'epigenetic' mechanism through which paternal age plays a role in telomere length regulation in humans. Based on two independent (discovery and replication) twin studies, comprising 889 twin pairs, we show an increase in the resemblance of leukocyte telomere length between dizygotic twins of older fathers, which is not seen in monozygotic twins. This phenomenon might result from a paternal age-dependent germ stem cell selection process, whereby the selected stem cells have longer telomeres, are more homogenous with respect to telomere length, and share resistance to aging.

  16. Mechanisms for initiation of cardiac discordant alternans

    NASA Astrophysics Data System (ADS)

    Echebarria, B.; Karma, A.

    2007-07-01

    Electrical alternans, defined as a beat-to-beat change in the duration of the excited phase of cardiac cells, is among the known precursors of sudden cardiac death. It may appear as concordant (all the tissue presenting the same phase of oscillation) or discordant (with out-of-phase regions distributed among tissue). Spatially discordant alternans can lead to unidirectional block that initiates reentry and ventricular fibrillation. The role played by tissue heterogeneities and heart rate changes in their initiation remains, however, unclear. We study the mechanisms for initiation of spatially discordant alternans by numerical simulations of an ionic model spatially distributed in a one-dimensional cable and in an anatomical model of the rabbit heart. The effects of CV-restitution, ectopic beats, and the role of spatial gradients of electrical restitution properties are investigated. In homogeneous tissue, the origin of discordant alternans may be dynamical, through CV-restitution, or due to a localized change in the pacing period. We also find that a sudden change of stimulation rate can initiate discordant alternans in the presence of a spatial gradient of APD-restitution without necessitating CV-restitution. The mechanism of, and the conditions for, initiation are determined based on an iterated map analysis of beat to beat changes of APD. This analysis leads to the definition of a vulnerable window for initiation of discordant alternans. Moreover, the pattern of spatially discordant alternans is found to change slowly over several beats following initiation, as reflected in ECG recordings.

  17. Twinning of dodecanedicarboxylic acid

    NASA Technical Reports Server (NTRS)

    Sen, R.; Wilcox, W. R.

    1986-01-01

    Twinning of 1,10-dodecanedicarboxyl acid (DDA) was observed in 0.1 mm thick films with a polarizing microscope. Twins originated from polycrystalline regions which tended to nucleate on twin faces, and terminated by intersection gone another. Twinning increased dramatically with addition of organic compounds with a similar molecular size and shape. Increasing the freezing rate, increasing the temperature gradient, and addition of silica particles increased twinning. It is proposed that twins nucleate with polycrystals and sometimes anneal out before they become observable. The impurities may enhance twinning either by lowering the twin energy or by adsorbing on growing faces.

  18. One-way unlocalizable quantum discord

    NASA Astrophysics Data System (ADS)

    Xi, Zhengjun; Fan, Heng; Li, Yongming

    2012-05-01

    In this paper, we present the concept of the one-way unlocalizable quantum discord and investigate its properties. We provide a polygamy inequality for it in a tripartite pure quantum system of arbitrary dimension. Several tradeoff relations between the one-way unlocalizable quantum discord and other correlations are given. If the von Neumann measurement is made on a part of the system, we give two expressions of the one-way unlocalizable quantum discord in terms of partial distillable entanglement and quantum disturbance. Finally, we also provide a lower bound for bipartite shareability of quantum correlation beyond entanglement in a tripartite system.

  19. Global quantum discord in multipartite systems

    SciTech Connect

    Rulli, C. C.; Sarandy, M. S.

    2011-10-15

    We propose a global measure for quantum correlations in multipartite systems, which is obtained by suitably recasting the quantum discord in terms of relative entropy and local von Neumann measurements. The measure is symmetric with respect to subsystem exchange and is shown to be nonnegative for an arbitrary state. As an illustration, we consider tripartite correlations in the Werner-GHZ (Greenberger-Horne-Zeilinger) state and multipartite correlations at quantum criticality. In particular, in contrast with the pairwise quantum discord, we show that the global quantum discord is able to characterize the infinite-order quantum phase transition in the Ashkin-Teller spin chain.

  20. Twin-to-twin transfusion syndrome

    MedlinePlus Videos and Cool Tools

    ... Transfusion Syndrome, or TTTS, is a disease of the placenta. This condition affects twins or other multiples ... containing blood vessels going from one baby to the other. Blood from the smaller "donor" twin is ...

  1. Heritability estimates of innate immunity: an extended twin study.

    PubMed

    de Craen, A J M; Posthuma, D; Remarque, E J; van den Biggelaar, A H J; Westendorp, R G J; Boomsma, D I

    2005-03-01

    Cytokines are key players in numerous inflammatory processes. Demonstration of a heritable component in the variation of cytokine production would indicate that simultaneous occurrence of conditions might be caused by a heritable inflammatory characteristic. We applied an extended twin study approach to assess heritability estimates of interleukin (IL)-1beta, IL-1ra, IL-10, IL-6, and TNF-alpha production capacity after ex vivo stimulation with lipopolysaccharide. Cytokine production capacity was assessed in 42 monozygotic pairs, 52 dizygotic pairs, one trizygotic triplet, 33 single twins, and 83 additional siblings. Heritability estimates were derived from variance decomposition models using maximum likelihood estimation. For all cytokines, over 50% of the variance was genetically determined. IL-1ra and TNF-alpha had the lowest heritability estimate of 53%. Estimates for IL-6 and IL-10 were 57 and 62%, respectively. IL-1beta had the highest estimate of 86%. We conclude that the production of cytokines is under tight genetic control. PMID:15674372

  2. Inheritance of finger pattern types in MZ and DZ twins.

    PubMed

    Karmakar, B; Malkin, I; Kobyliansky, E

    2011-08-01

    Digital patterns of a sample on twins were analyzed to estimate the resemblance between monozygotic (MZ) and dizygotic (DZ) twins and to evaluate the mode of inheritance by the use of maximum likelihood based variance decomposition analysis. MZ twin resemblance of finger pattern types appears to be more pronounced than in DZ twins, which suggests the presence of genetic factors in the forming of fingertip patterns. The most parsimonious model shows twin resemblance in count of all three basic finger patterns on 10 fingers. It has significant dominant genetic variance component across all fingers. In the general model, the dominant genetic variance component proportion is similar for all fingertips (about 60%) and the sibling environmental variance is significantly nonzero, but the proportion between additive and dominant variance components was different. Application of genetic model fitting technique of segregation analyses clearly shows mode of inheritance. A dominant genetic variance component or a specific genetic system modifies the phenotypic expression of the fingertip patterns. The present study provided evidence of strong genetic component in finger pattern types and seems more informative compared to the earlier traditional method of correlation analysis.

  3. Guidelines for scanning twins and triplets with US and MRI.

    PubMed

    Calvo-Garcia, Maria A

    2016-02-01

    Multiple-fetus gestations have an increased risk of discordant anomalies, aneuploidy and growth restriction compared to singleton pregnancies. In addition, twins sharing the same placenta are at risk for developing specific conditions that are potentially amenable to surgical management. In those scenarios, patients might need to be evaluated not only with US but with fetal MRI as well. This paper outlines basic guidelines to consider when imaging complicated multiple-fetus gestations during the 2nd and 3rd trimesters. PMID:26829946

  4. Associations between Sexual Abstinence Ideals, Religiosity, and Alcohol Abstinence: A Longitudinal Study of Finnish Twins

    PubMed Central

    Winter, Torsten; Karvonen, Sakari; Rose, Richard J.

    2016-01-01

    We analyzed prevalence and stability of attitudes endorsing sexual abstinence ideals from late adolescence into early adulthood and studied associations of these attitudes with religiosity and alcohol abstinence in a sexually liberal Nordic society. Our population-based sample of Finnish twins permitted comparisons of co-twins concordant for religiosity but discordant for drinking to evaluate the association of sexual abstinence ideals with alcohol abstinence, controlling for household environment. From age 17 to 24, endorsement of sexual abstinence as a romantic ideal declined from 25% to 15%. Religiosity and alcohol abstinence correlated, both separately and together, with endorsing sexual abstinence. Abstinence ideals were associated with literal belief in fundamental tenets of the Bible. The association of sexual abstinence ideals with alcohol abstinence was confirmed in within-family comparisons of co-twins discordant for drinking but concordant for religiosity. Alcohol-abstinent twins were significantly more likely than their non-alcohol-abstinent twin siblings to endorse sexual abstinence ideals; that result suggests the association of sexual abstinence ideals with abstaining from alcohol is not explained by unmeasured confounds in familial background and structure. Our longitudinal results and analyses of discordant twins suggest that attitudes toward sexual abstinence ideals are embedded within other conservative attitudes and behaviors. PMID:23301620

  5. Quantum Discord Cannot Be Shared

    NASA Astrophysics Data System (ADS)

    Streltsov, Alexander; Zurek, Wojciech H.

    2013-07-01

    Bohr proposed that the outcome of a measurement becomes objective and real, and, hence, classical, when its results can be communicated by classical means. In this work we revisit Bohr’s postulate using modern tools from quantum information theory. We find a full confirmation of Bohr’s idea: if a measurement device is in a nonclassical state, the measurement results cannot be communicated perfectly by classical means. In this case some part of the information in the measurement apparatus is lost in the process of communication: the amount of this lost information turns out to be the quantum discord. The information loss occurs even when the apparatus is not entangled with the system of interest. The tools presented in this work allow us to generalize Bohr’s postulate: we show that for pure system-apparatus states quantum communication does not provide any advantage when measurement results are communicated to more than one recipient. We further demonstrate the superiority of quantum communication to two recipients on a mixed system-apparatus state and show that this effect is fundamentally different from quantum state cloning.

  6. Race, zygosity, and mortality among twins: interaction of myth and method.

    PubMed

    Boklage, C E

    1987-01-01

    For epidemiological purposes, it is customary to assume that same-sex (SS) dizygotic (DZ) twin pairs are approximately equal in number to unlike-sex (OS)-DZs, the remainder of the SS pairs being monozygotic (MZ). It is also customary to consider OS-DZs to be epidemiologically representative of all DZs, which can only mean that difference in frequency of any trait between OS and SS twins is due to the MZ fraction of the SS twins. Since this is assumed as a premise, there is little value in its usual appearance as the result. The basic tenet of twin biology, that most twin excess anomalies are due to MZs, is a myth self-perpetuated by a methodological tautology, and is false, at least for mortality. In a consecutively ascertained and prospectively studied sample of 616 twin pairs, over 80% diagnosed for zygosity, it can be shown that the standard assumption mentioned above have given impossible answers. The most probable possible answer is that mortality does not differ greatly with zygosity overall, but that SSDZ mortality is much higher than that of OS twins, and probably even higher than that of MZs. Race differences in the probable answers further suggest that standard assumptions of the Weinberg method may have consistently provided false explanations for race differences in the OS fraction of twin pairs.

  7. Erythroblastosis of the Donor Twin of Twin Anemia-Polycythemia Sequence.

    PubMed

    Takeuchi, Miharu; Maruyama, Hidehiko; Oura, Naoko; Kanazawa, Akane; Nakata, Yusei; Minami, Susumu; Kikkawa, Kiyoshi

    2016-08-01

    Twin anemia-polycythemia sequence (TAPS) is a group of disorders in monochorionic twins characterized by a large intertwin hemoglobin difference without amniotic fluid discordance. Reticulocyte count is used to diagnose this condition, but little is known about the role of erythroblasts, which are the prior stage of reticulocytes. In the present case of TAPS, the 25-yr-old Japanese mother showed no signs of oligohydramnios or polyhydramnios throughout gestation. The twins were born at 36 weeks and 6 days, weighing 2,648g and 1,994g. The intertwin hemoglobin difference in umbilical cord blood was (21.1-5.0=) 16.1g/dL and the donor twin showed signs of chronic anemia, including myocardial hypertrophy and pericardial effusion. Erythroblastosis of the donor twin was prolonged (53,088.5, 42,114.8 and 44,217.9/μL on days 0, 1 and 2, respectively). Erythroblastosis, which indicates chronic anemia, is also a good diagnostic indicator of TAPS. PMID:27549671

  8. Examining Associations Among ADHD, Homework Behavior, and Reading Comprehension: A Twin Study.

    PubMed

    Little, Callie W; Hart, Sara A; Schatschneider, Christopher; Taylor, Jeanette

    2016-07-01

    Previous literature has indicated an important association between reading comprehension and both attention-deficit/hyperactivity disorder (ADHD) and homework habits. This investigation sought to extend previous knowledge by providing information about how ADHD and homework behavior (i.e., completing homework regularly) may jointly influence reading comprehension. Using a genetically sensitive design, this study examined the genetic and environmental influences on and between ADHD, homework behavior and reading comprehension. Participants for this study included 691 twin pairs (351 monozygotic, 340 same-sex dizygotic) from the Florida Twin Project on Behavior and Environment (FTP-BE) and 2647 twin pairs (865 monozygotic, 1782 dizygotic) from the larger Florida Twin Project on Reading (FTP-R) in Grades 3 through 7. Three separate models, each representing a different definition of ADHD (full ADHD, inattention only, and hyperactivity/impulsivity only), showed similar patterns of results; therefore, results of the full ADHD model are discussed. Overlapping genetic influences were found between ADHD, homework behavior, and reading comprehension, but no shared environmental influences among all three. However, shared environmental influences overlapped between homework behavior and reading comprehension. Although the sources of this environmental overlap are unknown, these results have implications for improving homework practices and their subsequent influence on literacy skills through homework environments.

  9. Examining Associations Among ADHD, Homework Behavior, and Reading Comprehension: A Twin Study.

    PubMed

    Little, Callie W; Hart, Sara A; Schatschneider, Christopher; Taylor, Jeanette

    2016-07-01

    Previous literature has indicated an important association between reading comprehension and both attention-deficit/hyperactivity disorder (ADHD) and homework habits. This investigation sought to extend previous knowledge by providing information about how ADHD and homework behavior (i.e., completing homework regularly) may jointly influence reading comprehension. Using a genetically sensitive design, this study examined the genetic and environmental influences on and between ADHD, homework behavior and reading comprehension. Participants for this study included 691 twin pairs (351 monozygotic, 340 same-sex dizygotic) from the Florida Twin Project on Behavior and Environment (FTP-BE) and 2647 twin pairs (865 monozygotic, 1782 dizygotic) from the larger Florida Twin Project on Reading (FTP-R) in Grades 3 through 7. Three separate models, each representing a different definition of ADHD (full ADHD, inattention only, and hyperactivity/impulsivity only), showed similar patterns of results; therefore, results of the full ADHD model are discussed. Overlapping genetic influences were found between ADHD, homework behavior, and reading comprehension, but no shared environmental influences among all three. However, shared environmental influences overlapped between homework behavior and reading comprehension. Although the sources of this environmental overlap are unknown, these results have implications for improving homework practices and their subsequent influence on literacy skills through homework environments. PMID:25349092

  10. APOL1 polymorphisms and development of CKD in an identical twin donor and recipient pair.

    PubMed

    Kofman, Tomek; Audard, Vincent; Narjoz, Céline; Gribouval, Olivier; Matignon, Marie; Leibler, Claire; Desvaux, Dominique; Lang, Philippe; Grimbert, Philippe

    2014-05-01

    We report an occurrence of progressive loss of transplant function and ultimately transplant failure after living related kidney transplantation involving monozygotic twin brothers of Afro-Caribbean origin who were both heterozygous for the G1 and G2 kidney disease risk alleles in the APOL1 gene, which encodes apolipoprotein L-I. A 21-year-old man with end-stage kidney disease of unknown cause received a kidney from his brother, who was confirmed as a monozygotic twin by microsatellite analysis. Thirty months after transplantation, the patient presented with proteinuria and decreased estimated glomerular filtration rate; a biopsy of the transplant showed typical focal segmental glomerulosclerosis lesions. He received steroid therapy, but progressed to kidney failure 5 years later. The twin brother had normal kidney function without proteinuria at the time of transplantation; however, 7 years later, he was found to have decreased estimated glomerular filtration rate (40mL/min/1.73m(2)) and proteinuria (protein excretion of 2.5g/d). APOL1 genotyping revealed that both donor and recipient were heterozygous for the G1 and G2 alleles. This case is in stark contrast to the expected course of kidney transplantation in identical twins and suggests a role for APOL1 polymorphisms in both the donor and recipient. PMID:24518129

  11. Zygosity differences in height and body mass index of twins from infancy to old age: A study of the CODATwins project

    PubMed Central

    Jelenkovic, Aline; Yokoyama, Yoshie; Sund, Reijo; Honda, Chika; Bogl, Leonie H; Aaltonen, Sari; Ji, Fuling; Ning, Feng; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Tarnoki, Adam D; Tarnoki, David L; Haworth, Claire MA; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Kim, Bia; Chong, Youngsook; Hong, Changhee; Shin, Hyun Jung; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth JF; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik KE; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos CEM; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Boomsma, Dorret I; Sørensen, Thorkild IA; Kaprio, Jaakko; Silventoinen, Karri

    2015-01-01

    A trend towards greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in means and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the CODATwins project and included 842,951 height and BMI measurements from age 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Likewise, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast the variance of BMI was significantly higher in DZ than in MZ twins particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes. PMID:26337138

  12. The natural course of monochorionic and dichorionic twin pregnancies: a historical cohort.

    PubMed

    Hack, Karien E A; Derks, Jan B; de Visser, Veerle L; Elias, Sjoerd G; Visser, Gerard H A

    2006-06-01

    Current early diagnosis, surveillance and intervention options make it hard to determine the natural course of twin pregnancies, especially regarding spontaneous preterm delivery and perinatal mortality. We studied the natural course in monochorionic (MC) and dichorionic (DC) twin pregnancies in a historical cohort. Twin pregnancies were studied in a unique database of 651 twin pairs born in the period 1907 to 1938. We examined the effect of chorionicity on gestational age, birthweight, perinatal mortality, intertwin birthweight differences, the incidence of preeclampsia and maternal mortality. Perinatal mortality was 27.7% for MC and 15.8% for DC twins (p < .001). Gestational age and birthweight were stronger predictors of perinatal mortality than chorionicity. Perinatal outcome was poorer for the second twin, especially in DC twins. Delivery before 37 weeks of gestation occurred more often in MC twin pregnancies (48.8% compared to 33.3% in DC twin pregnancies). DC twins were on average 288 g (95% confidence interval 201-376) heavier than MC twins. Severe birthweight discordancy occurred equally in MC and DC twins (18.1%). However, if present, mortality was only increased in MC twins. The birthweight of girls was not affected by the presence of a male co-twin. In this historical cohort MC twin pregnancies had a higher perinatal mortality, caused by a high incidence of low birthweight mainly due to preterm delivery. Mortality did not differ in deliveries after 31 weeks of gestation, which is in contrast to recent data. Apparently, modern obstetrics is more effective in reducing mortality in DC twins.

  13. Epidemiology of twinning in the National Birth Defects Prevention Study, 1997–2007

    PubMed Central

    Dawson, April L.; Tinker, Sarah C.; Jamieson, Denise J.; Hobbs, Charlotte A.; Rasmussen, Sonja A.; Reefhuis, Jennita

    2015-01-01

    Background Our objective was to evaluate associations between twinning and maternal demographic factors and periconceptional exposures among infants with and without orofacial clefts. Methods We used data from the National Birth Defects Prevention Study; 228 twins and 8,242 singletons without birth defects (controls), and 117 twins and 2,859 singletons with orofacial clefts, born 1997–2007, were included in the analyses. Because of the occurrence of twinning due to the use of assisted reproductive technologies, logistic regression models were computed to estimate odds ratios (OR) and 95% confidence intervals (CIs) for each exposure, stratified by fertility treatment use. To evaluate factors by zygosity, we used sex-pairing data and a simulation approach to estimate the zygosity of like-sex twin pairs for unassisted conceptions. Results Among control mothers who did not use fertility treatments, predictors of twinning included non-Hispanic black maternal race (adjusted OR: 1.6, 95% CI: 1.0–2.4), and tobacco smoking (1.6, 1.1–2.4). Among control mothers who used fertility treatments, older maternal age, higher income, and state of residence were associated with twinning. Associations were generally stronger among mothers of dizygotic (estimated) twins than monozygotic (estimated) twins. Results for mothers of infants with isolated orofacial clefts were similar to those of controls. Conclusion We observed an increased twinning frequency with increasing maternal age, but factors such as maternal race/ethnicity and socioeconomic status may also contribute. Among women receiving fertility treatments, factors associated with twinning suggested a relation with treatment specifics (e.g., treatment type and number of embryos implanted) and availability of insurance coverage. PMID:25359509

  14. Association between physical and motor development in childhood: a longitudinal study of Japanese twins.

    PubMed

    Silventoinen, Karri; Pitkäniemi, Janne; Latvala, Antti; Kaprio, Jaakko; Yokoyama, Yoshie

    2014-06-01

    Length and weight in infancy are associated with neurodevelopment, but less is known about growth in other anthropometric measures. In this study we analyzed how the development in length, weight, head circumference, and chest circumference over infancy is associated with motor development in early childhood, using a twin study design. Information on physical development over infancy and the age at achievement of eight developmental milestones over early childhood was collected for 370 Japanese twin pairs. Linear mixed models were used to analyze how physical development is associated with motor development between individual twins, as well as within twin pairs, adjusting the results for shared maternal and postnatal environmental factors. Delayed motor development was associated with smaller body size over infancy, and we also found some suggestive evidence that it was associated with catch-up growth as well. When studying the associations within twin pairs discordant for motor development, similar associations were found. However, chest circumference showed the most robust association within discordant twin pairs. Smaller body size and rapid catch-up growth are associated with delayed motor development. When studying these associations within twin pairs and thus adjusting the results for gestational age as well as many other maternal and postnatal environmental factors, chest circumference showed the most robust association. Chest circumference, rarely used in developed countries, can offer additional information on prenatal conditions relevant for further motor development not achieved by more traditional anthropometric measures.

  15. The Nature and Nurture of Melody: A Twin Study of Musical Pitch and Rhythm Perception.

    PubMed

    Seesjärvi, Erik; Särkämö, Teppo; Vuoksimaa, Eero; Tervaniemi, Mari; Peretz, Isabelle; Kaprio, Jaakko

    2016-07-01

    Both genetic and environmental factors are known to play a role in our ability to perceive music, but the degree to which they influence different aspects of music cognition is still unclear. We investigated the relative contribution of genetic and environmental effects on melody perception in 384 young adult twins [69 full monozygotic (MZ) twin pairs, 44 full dizygotic (DZ) twin pairs, 70 MZ twins without a co-twin, and 88 DZ twins without a co-twin]. The participants performed three online music tests requiring the detection of pitch changes in a two-melody comparison task (Scale) and key and rhythm incongruities in single-melody perception tasks (Out-of-key, Off-beat). The results showed predominantly additive genetic effects in the Scale task (58 %, 95 % CI 42-70 %), shared environmental effects in the Out-of-key task (61 %, 49-70 %), and non-shared environmental effects in the Off-beat task (82 %, 61-100 %). This highly different pattern of effects suggests that the contribution of genetic and environmental factors on music perception depends on the degree to which it calls for acquired knowledge of musical tonal and metric structures. PMID:26650514

  16. Ecosensitivity and genetic polymorphism of somatic traits in the perinatal development of twins.

    PubMed

    Waszak, Małgorzata; Cieślik, Krystyna; Skrzypczak-Zielińska, Marzena; Szalata, Marlena; Wielgus, Karolina; Kempiak, Joanna; Bręborowicz, Grzegorz; Słomski, Ryszard

    2016-04-01

    In view of criticism regarding the usefulness of heritability coefficients, the aim of this study was to analyze separately the information on genetic and environmental variability. Such an approach, based on the normalization of trait's variability for its value, is determined by the coefficients of genetic polymorphism (Pg) and ecosensitivity (De). The studied material included 1263 twin pairs of both sexes (among them 424 pairs of monozygotic twins and 839 pairs of dizygotic twins) born between the 22nd and 41st week of gestation. Variability of six somatic traits was analyzed. The zygosity of same-sex twins was determined based on the polymorphism of DNA from lymphocytes of the umbilical cord blood, obtained at birth. The coefficients of genetic polymorphism and ecosensitivity for analyzed traits of male and female twins born at various months of gestation were calculated. Our study revealed that a contribution of the genetic component predominated over that of the environmental component in determining the phenotypic variability of somatic traits of newborns from twin pregnancies. The genetically determined phenotypic variability in male twins was greater than in the females. The genetic polymorphism and ecosensitivity of somatic traits were relatively stable during the period of fetal ontogeny analyzed in this study. Only in the case of body weight, a slight increase in the genetic contribution of polygenes to the phenotypic variance could be observed with gestational age, along with a slight decrease in the influence of environmental factors.

  17. The effect of classroom environment on problem behaviors: a twin study.

    PubMed

    DiLalla, Lisabeth Fisher; Mullineaux, Paula Y

    2008-04-01

    Children's behavior problems, both internalizing and externalizing, are a function of both genetic and environmental influences. One potentially important environmental influence is the classroom environment. This study of 1941 monozygotic twin pairs examined whether children whose parents rated them as similarly high or low on a number of problem behaviors were rated in the same way by teachers when they were together versus separated in their classrooms at school. Results showed that twins in the same classrooms were rated by their teachers more similarly on each dimension of problem behavior than were twins who were separated into different classrooms, suggesting that the classroom environment is important in predicting differences between twins in terms of problem behaviors at school. In addition, parents' ratings of problem behaviors were lower for twins placed in the same classroom versus twins in different classrooms. Thus, there is reason to consider whether, at least during the early school years, parents should be allowed to make the decision to not separate twins at school.

  18. The Nature and Nurture of Melody: A Twin Study of Musical Pitch and Rhythm Perception.

    PubMed

    Seesjärvi, Erik; Särkämö, Teppo; Vuoksimaa, Eero; Tervaniemi, Mari; Peretz, Isabelle; Kaprio, Jaakko

    2016-07-01

    Both genetic and environmental factors are known to play a role in our ability to perceive music, but the degree to which they influence different aspects of music cognition is still unclear. We investigated the relative contribution of genetic and environmental effects on melody perception in 384 young adult twins [69 full monozygotic (MZ) twin pairs, 44 full dizygotic (DZ) twin pairs, 70 MZ twins without a co-twin, and 88 DZ twins without a co-twin]. The participants performed three online music tests requiring the detection of pitch changes in a two-melody comparison task (Scale) and key and rhythm incongruities in single-melody perception tasks (Out-of-key, Off-beat). The results showed predominantly additive genetic effects in the Scale task (58 %, 95 % CI 42-70 %), shared environmental effects in the Out-of-key task (61 %, 49-70 %), and non-shared environmental effects in the Off-beat task (82 %, 61-100 %). This highly different pattern of effects suggests that the contribution of genetic and environmental factors on music perception depends on the degree to which it calls for acquired knowledge of musical tonal and metric structures.

  19. Heritability of pain catastrophizing and associations with experimental pain outcomes: a twin study.

    PubMed

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R; Afari, Niloofar

    2015-03-01

    This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold-pressor Immersion Tolerance, Pain Tolerance, and Delayed Pain Rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, which suggests a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response. PMID:25599234

  20. Heritability of pain catastrophizing and associations with experimental pain outcomes: a twin study.

    PubMed

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R; Afari, Niloofar

    2015-03-01

    This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold-pressor Immersion Tolerance, Pain Tolerance, and Delayed Pain Rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, which suggests a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response.

  1. Intraventricular twin fetuses in fetu.

    PubMed

    Huddle, Lauren N; Fuller, Christine; Powell, Tiffany; Hiemenga, Judith A; Yan, Jia; Deuell, Brian; Lyders, Eric M; Bodurtha, Joann N; Papenhausen, Peter R; Jackson-Cook, Colleen K; Pandya, Arti; Jaworski, Margie; Tye, Gary W; Ritter, Ann M

    2012-01-01

    The authors report a rare case of multiple intracranial fetuses in fetu, fulfilling Willis' traditional criteria, which include an axial and appendicular skeleton with surrounding organized tissue. This case was ascertained from studies of a full-term female neonate who presented with ventriculomegaly. A CT scan showed intracranial calcifications that were suggestive of an axial skeleton. Her birth weight was 3.176 kg (50th-75th percentile), length was 52 cm (90th percentile), head circumference was 35 cm (50th-75th percentile), and Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. Prenatal ultrasonography studies performed at 12 weeks and 5 days, and 19 weeks and 6 days revealed normal findings. A 37-week prenatal ultrasonography study showed ventriculomegaly and obstructive hydrocephalus, with a possible intracranial teratoma. Cranial imaging at birth with ultrasonography, CT and MR imaging, and MR angiography demonstrated 2 complex intraventricular masses with cystic, solid, and bony elements. A craniotomy with resection of the masses was performed at 3 months of age. The infant survived and is now 12 months old with some developmental progress. Two axial skeletons, with accompanying rib cage and extremities, including well-formed feet and toes, were noted. Both anencephalic structures had skin with hair, fat, skeletal and smooth muscle, and bony structures with bone marrow and focal areas of calcification. Multiple viscera were present and included thymus, bowel, stomach, salivary gland, kidney, adrenal gland, lung, and presumed adnexal structures. A diagnosis of fetuses in fetu was rendered. Chromosomal studies of the child and tissue from the 2 fetuses in fetu showed normal female karyotypes. A single nucleotide polymorphism array analysis from the proband infant and tissue from the 2 identified fetuses in fetu appeared to be genetically identical. These results are consistent with a monozygotic twin embryonic origin of the fetus in fetu tissue

  2. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study.

    PubMed

    Montag, Christian; Hahn, Elisabeth; Reuter, Martin; Spinath, Frank M; Davis, Ken; Panksepp, Jaak

    2016-01-01

    The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research. PMID:26999649

  3. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study.

    PubMed

    Montag, Christian; Hahn, Elisabeth; Reuter, Martin; Spinath, Frank M; Davis, Ken; Panksepp, Jaak

    2016-01-01

    The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research.

  4. The Role of Nature and Nurture for Individual Differences in Primary Emotional Systems: Evidence from a Twin Study

    PubMed Central

    Reuter, Martin; Spinath, Frank M.; Davis, Ken; Panksepp, Jaak

    2016-01-01

    The present study investigated for the first time the relative importance of genetics and environment on individual differences in primary emotionality as measured with the Affective Neuroscience Personality Scales (ANPS) by means of a twin-sibling study design. In N = 795 participants (n = 303 monozygotic twins, n = 172 dizygotic twins and n = 267 non-twin full siblings), moderate to strong influences of genetics on individual differences in these emotional systems are observed. Lowest heritability estimates are presented for the SEEKING system (33%) and highest for the PLAY system (69%). Further, multivariate genetic modeling was applied to the data showing that associations among the six ANPS scales were influences by both, a genetic as well as an environmental overlap between them. In sum, the study underlines the usefulness of the ANPS for biologically oriented personality psychology research. PMID:26999649

  5. Marital Conflict and Conduct Problems in Children of Twins

    PubMed Central

    Harden, K. Paige; Turkheimer, Eric; Emery, Robert E.; D’Onofrio, Brian M.; Slutske, Wendy S.; Heath, Andrew C.; Martin, Nicholas G.

    2010-01-01

    The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14–39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate that genetic and nonshared environmental factors influence the risk of marital conflict. Furthermore, genetic influences mediated the association between marital conflict frequency and conduct problems. These results highlight the need for quasiexperimental designs in investigations of intergenerational associations. PMID:17328690

  6. Interpreting quantum discord through quantum state merging

    SciTech Connect

    Madhok, Vaibhav; Datta, Animesh

    2011-03-15

    We present an operational interpretation of quantum discord based on the quantum state merging protocol. Quantum discord is the markup in the cost of quantum communication in the process of quantum state merging, if one discards relevant prior information. Our interpretation has an intuitive explanation based on the strong subadditivity of von Neumann entropy. We use our result to provide operational interpretations of other quantities like the local purity and quantum deficit. Finally, we discuss in brief some instances where our interpretation is valid in the single-copy scenario.

  7. Healthy co-twins of patients with affective disorders show reduced risk-related activation of the insula during a monetary gambling task

    PubMed Central

    Macoveanu, Julian; Miskowiak, Kamilla; Kessing, Lars Vedel; Vinberg, Maj; Siebner, Hartwig Roman

    2016-01-01

    Background Healthy first-degree relatives of patients with affective disorders are at increased risk for affective disorders and express discrete structural and functional abnormalities in the brain reward system. However, value-based decision making is not well understood in these at-risk individuals. Methods We investigated healthy monozygotic and dizygotic twins with or without a co-twin history of affective disorders (high-risk and low-risk groups, respectively) using functional MRI during a gambling task. We assessed group differences in activity related to gambling risk over the entire brain. Results We included 30 monozygotic and 37 dizygotic twins in our analysis. Neural activity in the anterior insula and ventral striatum increased linearly with the amount of gambling risk in the entire cohort. Individual neuroticism scores were positively correlated with the neural response in the ventral striatum to increasing gambling risk and negatively correlated with individual risk-taking behaviour. Compared with low-risk twins, the high-risk twins showed a bilateral reduction of risk-related activity in the middle insula extending into the temporal cortex with increasing gambling risk. Post hoc analyses revealed that this effect was strongest in dizygotic twins. Limitations The relatively old average age of the mono- and dizygotic twin cohort (49.2 yr) may indicate an increased resilience to affective disorders. The size of the monozygotic high-risk group was relatively small (n = 13). Conclusion The reduced processing of risk magnitude in the middle insula may indicate a deficient integration of exteroceptive information related to risk-related cues with interoceptive states in individuals at familial risk for affective disorders. Impaired risk processing might contribute to increased vulnerability to affective disorders. PMID:26395812

  8. The CODAtwins project: the cohort description of COllaborative project of Development of Anthropometrical measures in Twins to study macro-environmental variation in genetic and environmental effects on anthropometric traits

    PubMed Central

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Honda, Chika; Aaltonen, Sari; Yokoyama, Yoshie; Tarnoki, Adam D; Tarnoki, David L; Ning, Feng; Ji, Fuling; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Haworth, Claire MA; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Hong, Changhee; Chong, Youngsook; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth JF; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik KE; Pedersen, Nancy L; Dahl-Aslan, Anna K; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos CEM; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Rasmussen, Finn; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Boomsma, Dorret I; Hur, Yoon-Mi; Sørensen, Thorkild IA; Kaprio, Jaakko

    2015-01-01

    For over one hundred years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically 1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and 2) to study the effects of birth related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects including both monozygotic and dizygotic twins using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes. PMID:26014041

  9. The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits.

    PubMed

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Honda, Chika; Aaltonen, Sari; Yokoyama, Yoshie; Tarnoki, Adam D; Tarnoki, David L; Ning, Feng; Ji, Fuling; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Haworth, Claire M A; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Hong, Changhee; Chong, Youngsook; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth J F; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos C E M; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Rasmussen, Finn; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Boomsma, Dorret I; Hur, Yoon-Mi; Sørensen, Thorkild I A; Kaprio, Jaakko

    2015-08-01

    For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.

  10. The CODATwins Project: The Cohort Description of Collaborative Project of Development of Anthropometrical Measures in Twins to Study Macro-Environmental Variation in Genetic and Environmental Effects on Anthropometric Traits.

    PubMed

    Silventoinen, Karri; Jelenkovic, Aline; Sund, Reijo; Honda, Chika; Aaltonen, Sari; Yokoyama, Yoshie; Tarnoki, Adam D; Tarnoki, David L; Ning, Feng; Ji, Fuling; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Haworth, Claire M A; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Hong, Changhee; Chong, Youngsook; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth J F; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos C E M; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Rasmussen, Finn; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Boomsma, Dorret I; Hur, Yoon-Mi; Sørensen, Thorkild I A; Kaprio, Jaakko

    2015-08-01

    For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes. PMID:26014041

  11. Parental Marital Discord and Treatment Response in Depressed Adolescents

    ERIC Educational Resources Information Center

    Amaya, Meredith M.; Reinecke, Mark A.; Silva, Susan G.; March, John S.

    2011-01-01

    Evidence suggests that parental marital discord contributes to the development of internalizing and externalizing symptoms in children and adolescents. Few studies, however, have examined the association between parental marital discord and youth's response to treatment. The present study examined the impact of interparental discord on treatment…

  12. Online Social Interchange, Discord, and Knowledge Construction.

    ERIC Educational Resources Information Center

    Kanuka, Heather; Anderson, Terry

    1998-01-01

    Presents the results of an exploratory multi-method evaluation study and transcript analysis of an online forum. Highlights include use of a constructivist interaction analysis model to help understand and assess online learning; social interchange; and social discord and knowledge construction. (Author/LRW)

  13. Entanglement as minimal discord over state extensions

    NASA Astrophysics Data System (ADS)

    Luo, Shunlong

    2016-09-01

    The characterization and quantification of quantum correlations, which play an instrumental role in exploring and exploiting the quantum world, have been extensively and intensively studied in the past few decades. Of special prominence and significance are the concepts of entanglement and discord, which are usually regarded as very distinctive quantum correlations, with the latter going beyond the former. In this work we establish a direct and natural link between entanglement and discord via state extensions and reveal that entanglement is actually the intrinsic discord, by which we mean that entanglement is the irreducible residue of discord viewed from ambient spaces. Our approach, taking into account the contextuality of a quantum state and being of a global nature, stands in sharp contrast to the local operations and classical communication paradigm of entanglement, which focuses on the state itself via a local approach. Furthermore, we introduce a figure of merit which, on the one hand, captures the essence of entanglement, i.e., nonlocality and quantumness of correlations, and, on the other hand, leads to a quantitative decomposition of total correlations into classical correlations, dissonance, and entanglement. This demystifies the meaning of entanglement from the perspective of quantum measurements and provides a unified framework for the interplay of various correlations in terms of quantum measurements and mutual information.

  14. Investigating brain connectivity heritability in a twin study using diffusion imaging data

    PubMed Central

    Shen, Kai-Kai; Rose, Stephen; Fripp, Jurgen; McMahon, Katie L.; de Zubicaray, Greig I.; Martin, Nicholas G.; Thompson, Paul M.; Wright, Margaret J.; Salvado, Olivier

    2014-01-01

    Heritability of brain anatomical connectivity has been studied with diffusion-weighted imaging (DWI) mainly by modeling each voxel's diffusion pattern as a tensor (e.g., to compute fractional anisotropy), but this method cannot accurately represent the many crossing connections present in the brain. We hypothesized that different brain networks (i.e., their component fibers) might have different heritability and we investigated brain connectivity using High Angular Resolution Diffusion Imaging (HARDI) in a cohort of twins comprising 328 subjects that included 70 pairs of monozygotic and 91 pairs of dizygotic twins. Water diffusion was modeled in each voxel with a Fiber Orientation Distribution (FOD) function to study heritability for multiple fiber orientations in each voxel. Precision was estimated in a test–retest experiment on a sub-cohort of 39 subjects. This was taken into account when computing heritability of FOD peaks using an ACE model on the monozygotic and dizygotic twins. Our results confirmed the overall heritability of the major white matter tracts but also identified differences in heritability between connectivity networks. Inter-hemispheric connections tended to be more heritable than intra-hemispheric and cortico-spinal connections. The highly heritable tracts were found to connect particular cortical regions, such as medial frontal cortices, postcentral, paracentral gyri, and the right hippocampus. PMID:24973604

  15. Twinning rates in Tamilnadu.

    PubMed Central

    Rao, P S; Inbaraj, S G; Muthurathnam, S

    1983-01-01

    A prospective study of human reproduction was conducted in Tamilnadu State, South India, from 1969 to 1975. This paper reports twinning rates and relates these to maternal age, parity, and consanguinity. Birth weights and other dimensions at birth and infant mortality are also studied. The overall twinning rate was 1 in 115 births. Dizygotic twinning rates increased significantly with maternal age and parity. The measurements at birth for like-sexed twin pairs were lower than that of unlike-sexed, but the mortalities did not differ significantly. Twins, in general, had a several fold increase in mortality as compared with singletons. PMID:6886580

  16. Merohedral twins revisited: quinary twins and beyond.

    PubMed

    Quiquandon, Marianne; Gratias, Denis; Sirindil, Abdullah; Portier, Richard

    2016-01-01

    A twin is defined as being an external operation between two identical crystals that share a fraction of the atomic structure with no discontinuity from one crystal to the other. This includes merohedral twins, twins by reticular merohedry as well as coherent twins by contact where only the habit plane is shared by the two adjacent crystals (epitaxy). Interesting and original cases appear when the invariant substructure is built with positions belonging to the same {\\bb Z}-module as, for example, the quinary twin structure first drawn by Albrecht Dürer [(1525). The Painter's Manual: a Manual of Measurement of Lines, Areas and Solids by Means of Compass and Ruler. Facsimile Edition (1977), translated with commentary by W. L. Strauss. New York: Abaris Books]. This paper will show that the Dürer twins, once defined in five-dimensional space, are simple merohedral twins, in the sense of Georges Friedel, leaving the five-dimensional lattice invariant. This analysis will be generalized to some other higher-order {\\bb Z}-modules. PMID:26697867

  17. Merohedral twins revisited: quinary twins and beyond

    PubMed Central

    Quiquandon, Marianne; Gratias, Denis; Sirindil, Abdullah; Portier, Richard

    2016-01-01

    A twin is defined as being an external operation between two identical crystals that share a fraction of the atomic structure with no discontinuity from one crystal to the other. This includes merohedral twins, twins by reticular merohedry as well as coherent twins by contact where only the habit plane is shared by the two adjacent crystals (epitaxy). Interesting and original cases appear when the invariant substructure is built with positions belonging to the same -module as, for example, the quinary twin structure first drawn by Albrecht Dürer [(1525 ▸). The Painter’s Manual: a Manual of Measurement of Lines, Areas and Solids by Means of Compass and Ruler. Facsimile Edition (1977), translated with commentary by W. L. Strauss. New York: Abaris Books]. This paper will show that the Dürer twins, once defined in five-dimensional space, are simple merohedral twins, in the sense of Georges Friedel, leaving the five-dimensional lattice invariant. This analysis will be generalized to some other higher-order -modules. PMID:26697867

  18. Asymmetric twin Dark Matter

    SciTech Connect

    Farina, Marco

    2015-11-09

    We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  19. Asymmetric twin Dark Matter

    SciTech Connect

    Farina, Marco

    2015-11-01

    We study a natural implementation of Asymmetric Dark Matter in Twin Higgs models. The mirroring of the Standard Model strong sector suggests that a twin baryon with mass around 5 GeV is a natural Dark Matter candidate once a twin baryon number asymmetry comparable to the SM asymmetry is generated. We explore twin baryon Dark Matter in two different scenarios, one with minimal content in the twin sector and one with a complete copy of the SM, including a light twin photon. The essential requirements for successful thermal history are presented, and in doing so we address some of the cosmological issues common to many Twin Higgs models. The required interactions we introduce predict signatures at direct detection experiments and at the LHC.

  20. Asthma and height in twins: a cohort and within-pair analyses study.

    PubMed

    Protudjer, Jennifer L P; Lundholm, Cecilia; Almqvist, Catarina

    2015-04-01

    In singletons, asthma may be associated with shorter height and delayed growth during adolescence. Yet, these studies do not account for heritability of asthma, puberty/menarche, and height. We aimed to study the association between asthma and puberty in boys and menarche in girls, and height, in a cohort of twins and subsequently in same-sex twin pairs discordant for asthma. From a Swedish twin cohort, parent- and self-reported data on asthma, puberty/menarche, and height were collected. Pubertal staging was established via the Petersen index. Logistic and linear regression was used to estimate associations between asthma and puberty/menarche and height, respectively. For within-pair analyses in twins discordant for asthma, conditional logistic and linear regression were used. Data on 2,658 (49.1% boys) twins were included. Among boys, asthma prevalence was 8.2% at 8-9 years and 10.2% at 13-14 years. Corresponding numbers for girls were 4.2% and 4.9%, respectively. In the entire cohort, no statistically significant associations were found between current asthma and puberty/menarche. Boys with asthma were shorter than boys without asthma at 8-9 years (on average, 1.86 [0.17-3.56] cm, p = .03) and at 13-14 years (on average, 2.94 [0.98-4.91] cm, p = .003) but not at 19-20 years. No such associations were found for girls. Within same-sex twin pairs discordant for asthma, no statistically significant associations were found for either sex. Twin boys, but not girls, with asthma were shorter than those without asthma. Non-statistically significant estimates from within-pair analyses suggest the association is partly confounded by genetic or familial environmental factors. PMID:25761570

  1. Genetic, epigenetic, and environmental influences on dentofacial structures and oral health: ongoing studies of Australian twins and their families.

    PubMed

    Hughes, Toby; Bockmann, Michelle; Mihailidis, Suzanna; Bennett, Corinna; Harris, Abbe; Seow, W Kim; Lekkas, Dimitra; Ranjitkar, Sarbin; Rupinskas, Loreta; Pinkerton, Sandra; Brook, Alan; Smith, Richard; Townsend, Grant C

    2013-02-01

    The Craniofacial Biology Research Group in the School of Dentistry at The University of Adelaide is entering an exciting new phase of its studies of dental development and oral health in twins and their families. Studies of the teeth and faces of Australian twins have been continuing for nearly 30 years, with three major cohorts of twins recruited over that time, and currently we are working with twins aged 2 years old to adults. Cross-sectional data and records relating to teeth and faces of twins are available for around 300 pairs of teenage twins, as well as longitudinal data for 300 pairs of twins examined at three different stages of development, once with primary teeth, once at the mixed dentition stage, and then again when the permanent teeth had emerged. The third cohort of twins comprises over 600 pairs of twins recruited at around birth, together with other family members. The emphasis in this third group of twins has been to record the timing of emergence of the primary teeth and also to sample saliva and dental plaque to establish the timing of colonization of decay-forming bacteria in the mouth. Analyses have confirmed that genetic factors strongly influence variation in timing of primary tooth emergence. The research team is now beginning to carry out clinical examinations of the twins to see whether those who become colonized earlier with decay-forming bacteria develop dental decay at an earlier age. By making comparisons within and between monozygotic (MZ) and dizygotic (DZ) twin pairs and applying modern molecular approaches, we are now teasing out how genetic, epigenetic, and environmental factors interact to influence dental development and also oral health.

  2. Comparing Facial 3D Analysis With DNA Testing to Determine Zygosities of Twins.

    PubMed

    Vuollo, Ville; Sidlauskas, Mantas; Sidlauskas, Antanas; Harila, Virpi; Salomskiene, Loreta; Zhurov, Alexei; Holmström, Lasse; Pirttiniemi, Pertti; Heikkinen, Tuomo

    2015-06-01

    The aim of this study was to compare facial 3D analysis to DNA testing in twin zygosity determinations. Facial 3D images of 106 pairs of young adult Lithuanian twins were taken with a stereophotogrammetric device (3dMD, Atlanta, Georgia) and zygosity was determined according to similarity of facial form. Statistical pattern recognition methodology was used for classification. The results showed that in 75% to 90% of the cases, zygosity determinations were similar to DNA-based results. There were 81 different classification scenarios, including 3 groups, 3 features, 3 different scaling methods, and 3 threshold levels. It appeared that coincidence with 0.5 mm tolerance is the most suitable feature for classification. Also, leaving out scaling improves results in most cases. Scaling was expected to equalize the magnitude of differences and therefore lead to better recognition performance. Still, better classification features and a more effective scaling method or classification in different facial areas could further improve the results. In most of the cases, male pair zygosity recognition was at a higher level compared with females. Erroneously classified twin pairs appear to be obvious outliers in the sample. In particular, faces of young dizygotic (DZ) twins may be so similar that it is very hard to define a feature that would help classify the pair as DZ. Correspondingly, monozygotic (MZ) twins may have faces with quite different shapes. Such anomalous twin pairs are interesting exceptions, but they form a considerable portion in both zygosity groups.

  3. Diversity of Gut Microbiota Metabolic Pathways in 10 Pairs of Chinese Infant Twins

    PubMed Central

    Wang, Yan; Zhou, Jianli; Zhou, Wenhao

    2016-01-01

    Early colonization of gut microbiota in human gut is a complex process. It remains unclear when gut microbiota colonization occurs and how it proceeds. In order to study gut microbiota composition in human early life, the present study recruited 10 healthy pairs of twins, including five monozygotic (MZ) and five dizygotic (DZ) twin pairs, whose age ranged from 0 to 6 years old. 20 fecal samples from these twins were processed by shotgun metagenomic sequencing, and their averaged data outputs were generated as 2G per sample. We used MEGAN5 to perform taxonomic and functional annotation of the metagenomic data, and systematically analyzed those 20 samples, including Jaccard index similarity, principle component, clustering, and correlation analyses. Our findings indicated that within our study group: 1) MZ-twins share more microbes than DZ twins or non-twin pairs, 2) gut microbiota distribution is relatively stable at metabolic pathways level, 3) age represents the strongest factor that can account for variation in gut microbiota, and 4) a clear metabolic pathway shift can be observed, which speculatively occurs around the age of 1 year old. This research will serve as a base for future studies of gut microbiota-related disease research. PMID:27583441

  4. Inheritance of dermatoglyphic asymmetry and diversity traits in twins based on factor: variance decomposition analysis.

    PubMed

    Karmakar, Bibha; Malkin, Ida; Kobyliansky, Eugene

    2013-06-01

    Dermatoglyphic asymmetry and diversity traits from a large number of twins (MZ and DZ) were analyzed based on principal factors to evaluate genetic effects and common familial environmental influences on twin data by the use of maximum likelihood-based Variance decomposition analysis. Sample consists of monozygotic (MZ) twins of two sexes (102 male pairs and 138 female pairs) and 120 pairs of dizygotic (DZ) female twins. All asymmetry (DA and FA) and diversity of dermatoglyphic traits were clearly separated into factors. These are perfectly corroborated with the earlier studies in different ethnic populations, which indicate a common biological validity perhaps exists of the underlying component structures of dermatoglyphic characters. Our heritability result in twins clearly showed that DA_F2 is inherited mostly in dominant type (28.0%) and FA_F1 is additive (60.7%), but no significant difference in sexes was observed for these factors. Inheritance is also very prominent in diversity Factor 1, which is exactly corroborated with our previous findings. The present results are similar with the earlier results of finger ridge count diversity in twin data, which suggested that finger ridge count diversity is under genetic control.

  5. Diversity of Gut Microbiota Metabolic Pathways in 10 Pairs of Chinese Infant Twins.

    PubMed

    Zhou, Shaoming; Xu, Ruihuan; He, Fusheng; Zhou, Jiaxiu; Wang, Yan; Zhou, Jianli; Wang, Mingbang; Zhou, Wenhao

    2016-01-01

    Early colonization of gut microbiota in human gut is a complex process. It remains unclear when gut microbiota colonization occurs and how it proceeds. In order to study gut microbiota composition in human early life, the present study recruited 10 healthy pairs of twins, including five monozygotic (MZ) and five dizygotic (DZ) twin pairs, whose age ranged from 0 to 6 years old. 20 fecal samples from these twins were processed by shotgun metagenomic sequencing, and their averaged data outputs were generated as 2G per sample. We used MEGAN5 to perform taxonomic and functional annotation of the metagenomic data, and systematically analyzed those 20 samples, including Jaccard index similarity, principle component, clustering, and correlation analyses. Our findings indicated that within our study group: 1) MZ-twins share more microbes than DZ twins or non-twin pairs, 2) gut microbiota distribution is relatively stable at metabolic pathways level, 3) age represents the strongest factor that can account for variation in gut microbiota, and 4) a clear metabolic pathway shift can be observed, which speculatively occurs around the age of 1 year old. This research will serve as a base for future studies of gut microbiota-related disease research. PMID:27583441

  6. Mirror imaging of impacted and supernumerary teeth in dizygotic twins: A case report

    PubMed Central

    Altieri, Federica; Giordano, Alessandra

    2015-01-01

    Background: Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the clinical examination by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. Mirror imaging in twins has been reported frequently in relation to several unilateral dental anomalies including mesiodens. This phenomenon is the appearance of an asymmetrical feature or anomaly occurring on the right side of one twin but on the left side of the other twin. The event of mesiodens mirror imaging in monozygotic twins has been described in literature. Results: This is the first reported case of mesiodens mirror images in dizygotic twins. The de-scribed mesiodens caused the eruption failure of maxillary permanent incisors. The super-numerary teeth were removed to facilitate the spontaneous eruption of the impacted perma-nent maxillary incisors. Clinical Implications: Studies related to supernumerary teeth can be useful to clinicians in the early diagnosis of this anomaly. Clinical and radiographic examinations provide a correct therapeutic approach. Key words:Supernumerary teeth, twins, dental development. PMID:25810831

  7. High angular resolution diffusion imaging in a child with autism spectrum disorder and comparison with his unaffected identical twin

    PubMed Central

    Conti, Eugenia; Pannek, Kerstin; Calderoni, Sara; Gaglianese, Anna; Fiori, Simona; Brovedani, Paola; Scelfo, Danilo; Rose, Stephen; Tosetti, Michela; Cioni, Giovanni; Guzzetta, Andrea

    2015-01-01

    Summary In recent years, the use of brain diffusion MRI has led to the hypothesis that children with autism spectrum disorder (ASD) show abnormally connected brains. We used the model of disease-discordant identical twins to test the hypothesis that higher-order diffusion MRI protocols are able to detect abnormal connectivity in a single subject. We studied the structural connectivity of the brain of a child with ASD, and of that of his unaffected identical twin, using high angular resolution diffusion imaging (HARDI) probabilistic tractography. Cortical regions were automatically parcellated from high-resolution structural images, and HARDI-based connection matrices were produced for statistical comparison. Differences in diffusion indexes between subjects were tested by Wilcoxon signed rank test. Tracts were defined as discordant when they showed a between-subject difference of 10 percent or more. Around 11 percent of the discordant intra-hemispheric tracts showed lower fractional anisotropy (FA) values in the ASD twin, while only 1 percent showed higher values. This difference was significant. Our findings in a disease-discordant identical twin pair confirm previous literature consistently reporting lower FA values in children with ASD. PMID:26446271

  8. High angular resolution diffusion imaging in a child with autism spectrum disorder and comparison with his unaffected identical twin.

    PubMed

    Conti, Eugenia; Pannek, Kerstin; Calderoni, Sara; Gaglianese, Anna; Fiori, Simona; Brovedani, Paola; Scelfo, Danilo; Rose, Stephen; Tosetti, Michela; Cioni, Giovanni; Guzzetta, Andrea

    2015-01-01

    In recent years, the use of brain diffusion MRI has led to the hypothesis that children with autism spectrum disorder (ASD) show abnormally connected brains. We used the model of disease-discordant identical twins to test the hypothesis that higher-order diffusion MRI protocols are able to detect abnormal connectivity in a single subject. We studied the structural connectivity of the brain of a child with ASD, and of that of his unaffected identical twin, using high angular resolution diffusion imaging (HARDI) probabilistic tractography. Cortical regions were automatically parcellated from high-resolution structural images, and HARDI-based connection matrices were produced for statistical comparison. Differences in diffusion indexes between subjects were tested by Wilcoxon signed rank test. Tracts were defined as discordant when they showed a between-subject difference of 10 percent or more. Around 11 percent of the discordant intra-hemispheric tracts showed lower fractional anisotropy (FA) values in the ASD twin, while only 1 percent showed higher values. This difference was significant. Our findings in a disease-discordant identical twin pair confirm previous literature consistently reporting lower FA values in children with ASD. PMID:26446271

  9. High angular resolution diffusion imaging in a child with autism spectrum disorder and comparison with his unaffected identical twin.

    PubMed

    Conti, Eugenia; Pannek, Kerstin; Calderoni, Sara; Gaglianese, Anna; Fiori, Simona; Brovedani, Paola; Scelfo, Danilo; Rose, Stephen; Tosetti, Michela; Cioni, Giovanni; Guzzetta, Andrea

    2015-01-01

    In recent years, the use of brain diffusion MRI has led to the hypothesis that children with autism spectrum disorder (ASD) show abnormally connected brains. We used the model of disease-discordant identical twins to test the hypothesis that higher-order diffusion MRI protocols are able to detect abnormal connectivity in a single subject. We studied the structural connectivity of the brain of a child with ASD, and of that of his unaffected identical twin, using high angular resolution diffusion imaging (HARDI) probabilistic tractography. Cortical regions were automatically parcellated from high-resolution structural images, and HARDI-based connection matrices were produced for statistical comparison. Differences in diffusion indexes between subjects were tested by Wilcoxon signed rank test. Tracts were defined as discordant when they showed a between-subject difference of 10 percent or more. Around 11 percent of the discordant intra-hemispheric tracts showed lower fractional anisotropy (FA) values in the ASD twin, while only 1 percent showed higher values. This difference was significant. Our findings in a disease-discordant identical twin pair confirm previous literature consistently reporting lower FA values in children with ASD.

  10. Thermal geometric discords in a two-qutrit system

    NASA Astrophysics Data System (ADS)

    Yuan, Ya-Li; Hou, Xi-Wen

    2016-06-01

    The investigation of quantum discord has mostly focused on two-qubit systems due to the complicated minimization involved in quantum discord for high-dimensional states. In this work, three geometric discords are studied for the thermal state in a two-qutrit system with various couplings, external magnetic fields, and temperatures as well, where the entanglement measured in terms of the generalized negativity is calculated for reference. It is shown that three geometric discords are more robust against temperature and magnetic field than the entanglement negativity. However, all four quantities exhibit a similar behavior at lower temperature and weak magnetic field. Remarkably, three geometric discords at finite temperature reveal the phenomenon of double sudden changes at different magnetic fields while the negativity does not. Moreover, the hierarchy among three discords is discussed. Those adjustable discords with the varied coupling, temperature, and magnetic field are useful for the understanding of quantum correlations in high-dimensional states and quantum information processing.

  11. Preservation of the geometric quantum discord in noisy environments

    SciTech Connect

    Hu, Ming-Liang; Tian, Dong-Ping

    2014-04-15

    Geometric description of quantum correlations is favored for their distinct physical significance. Geometric discords based on the trace distance and the Bures distance are shown to be well-defined quantum correlation measures. Here, we examine their particular dynamical behaviors under independent as well as common structured reservoirs and reveal their robustness against decoherence. We showed that the two well-defined geometric discords may be preserved well or even be improved and generated by the noisy process of the common reservoir. Moreover, we also provided a strategy for the long-time preservation of these two geometric discords in independent reservoirs. -- Highlights: •Inherent robustness of the trace distance and the Bures distance discord. •Generating geometric discord from classical states by the noisy process. •Improvement of the geometric discord in common reservoir. •The robust pathway for preserving discord in independent reservoirs.

  12. Clinical factors affecting the timing of delivery in twin pregnancies

    PubMed Central

    Lee, Chae Min; Yang, Sun Hye; Lee, Sun Pyo; Hwang, Byung Chul

    2014-01-01

    Objective To investigate clinical factors affecting the timing of delivery in twin pregnancies in order to minimize perinatal complications. Methods A retrospective study involved 163 twin pregnancies delivered from January 2006 to September 2011 at Gachon University Gil Medical Center. These cases were divided into three groups based on the delivery timing: less than 32 weeks' gestation (group A), between 32 and 35+6 weeks' gestation (group B), and over 36 weeks' gestation (group C). Clinical factors including maternal age, parity, presence of premature uterine contraction, presence of premature rupture of membrane, white blood cell, high sensitive C-reactive protein level, cervical dilatation, maternal complication, chorionicity, twin specific complication, and perinatal complication were analyzed for each group. Results In group B, the timing of delivery was postponed for 14 days or more from the time of admission, and there were fewer numbers of babies with low Apgar score at birth compared with other groups. The frequency of uterine contraction (P<0.001), presence of premature rupture of membranes (P=0.017), dilatation of cervix (P<0.001), increased white blood cell and high sensitive C-reactive protein levels (P=0.002, P<0.001) were important clinical factors during decision making process of delivery timing in twin pregnancies. Twin specific fetal conditions, such as twin-twin transfusion syndrome and discordant growth (over 25% or more) were shown more frequently in group A. However, there were no significant statistical differences among three groups (P=0.06, P=0.14). Conclusion Proper management for preventing premature contraction and inflammation can be essential in twin pregnancies until 32 weeks' gestation, and may decrease maternal and perinatal complications. PMID:25469330

  13. A Comparison of Disease Burden Between Twins and Control Pairs in Medicare: Quantification of Heredity's Role in Human Health.

    PubMed

    Sorace, James; Rogers, Michael; Millman, Michael; Rogers, Daniel; Price, Kyle; Queen, Susan; Worrall, Chris; Kelman, Jeffrey

    2015-10-01

    To quantify heredity's effects on the burden of illness in the Medicare population, this study linked information between participants in a research twin registry to a comprehensive set of Medicare claims. To calculate disease categories, the authors used the Centers for Medicare & Medicaid Services Hierarchical Conditions Categories (HCC) model that was developed to risk adjust Medicare's capitation payments to private health care plans based on the health expenditure risk of their enrollees. Using the Medicare database, 2 sets of unrelated but demographically matched control pairs (MCPs) were generated, one specific for the monozygotic twin population and the second specific for the dizygotic twin population. The concordance and correlation rates of the 70 HCC categories for the 2 twin populations, in comparison to their corresponding MCP, was then calculated using Medicare claims data from 1991 through 2011. When indicated, HCCs for which there was a statistically significant difference between the twin and corresponding MCP control group were analyzed by calculating concordance and correlation rates of the International Classification of Diseases, Ninth Revision codes that compose the HCC. Findings reveal that monozygotic twins share 6.5% more HCC disease categories than their MCP while dizygotic twins share 3.8% more HCC disease categories than their MCP. Atrial fibrillation is a highly heritable disease category, a finding consistent with prior literature describing the heritability of the cardiac arrhythmias. These findings are consistent with qualitative assessments of heredity's role found in previous models of population health, and provide both novel methods and quantitative evidence to support future model development. PMID:25658666

  14. A Comparison of Disease Burden Between Twins and Control Pairs in Medicare: Quantification of Heredity's Role in Human Health.

    PubMed

    Sorace, James; Rogers, Michael; Millman, Michael; Rogers, Daniel; Price, Kyle; Queen, Susan; Worrall, Chris; Kelman, Jeffrey

    2015-10-01

    To quantify heredity's effects on the burden of illness in the Medicare population, this study linked information between participants in a research twin registry to a comprehensive set of Medicare claims. To calculate disease categories, the authors used the Centers for Medicare & Medicaid Services Hierarchical Conditions Categories (HCC) model that was developed to risk adjust Medicare's capitation payments to private health care plans based on the health expenditure risk of their enrollees. Using the Medicare database, 2 sets of unrelated but demographically matched control pairs (MCPs) were generated, one specific for the monozygotic twin population and the second specific for the dizygotic twin population. The concordance and correlation rates of the 70 HCC categories for the 2 twin populations, in comparison to their corresponding MCP, was then calculated using Medicare claims data from 1991 through 2011. When indicated, HCCs for which there was a statistically significant difference between the twin and corresponding MCP control group were analyzed by calculating concordance and correlation rates of the International Classification of Diseases, Ninth Revision codes that compose the HCC. Findings reveal that monozygotic twins share 6.5% more HCC disease categories than their MCP while dizygotic twins share 3.8% more HCC disease categories than their MCP. Atrial fibrillation is a highly heritable disease category, a finding consistent with prior literature describing the heritability of the cardiac arrhythmias. These findings are consistent with qualitative assessments of heredity's role found in previous models of population health, and provide both novel methods and quantitative evidence to support future model development.

  15. Twin-to-twin transfusion syndrome

    MedlinePlus

    ... skin, too much blood, and a higher blood pressure. The twin that gets too much blood may develop cardiac failure because of the high blood volume. The infant may also need medicine to strengthen ...

  16. Effects of Smoking on Coronary Microcirculatory Function: A Twin Study

    PubMed Central

    Rooks, Cherie; Faber, Tracy; Votaw, John; Veledar, Emir; Goldberg, Jack; Raggi, Paolo; Quyyumi, Arshed A.; Bremner, J. Douglas; Vaccarino, Viola

    2011-01-01

    Background In asymptomatic smokers, coronary microcirculatory dysfunction, assessed by coronary flow reserve (CFR), is an early indicator of cardiovascular risk. Inflammation and oxidative stress may be the mechanisms through which smoking affects the microvasculature. Objectives The purpose of this study was to determine the relationship between smoking and CFR, taking into account potential shared genetic effects. Methods We examined 360 male middle aged twins (288 non-smokers and 72 smokers), including 46 twin pairs discordant for current smoking. Coronary flow reserve (CFR) in response to adenosine was measured with positron emission tomography [N13] ammonia and quantitation of coronary blood flow at rest and after adenosine stress. Inflammation was assessed by measuring interleukin-6 and C-reactive protein, and oxidative stress was determined by measuring plasma hydroperoxides, glutathione (GSH), the oxidized form of GSH, GSSG, and the ratio of GSH to GSSG. Results CFR was significantly lower in smokers compared to nonsmokers (2.25 vs. 2.75, p<0.01). This relationship persisted after accounting for known cardiovascular disease risk factors, and was marginally affected by adjusting for inflammatory and oxidative stress biomarkers. In addition, in smoking-discordant twin pairs, CFR in the smoking twin was significantly lower than in the non-smoking co-twin (2.25 vs. 2.67, p = 0.03) even after adjustment for cardiovascular risk factors. Conclusions Our results demonstrate the adverse effects of smoking in the early phases of cardiovascular disease. Mechanisms other than peripherally-measured inflammation and oxidative stress are involved. PMID:21315354

  17. A core gut microbiome in obese and lean twins.

    PubMed

    Turnbaugh, Peter J; Hamady, Micah; Yatsunenko, Tanya; Cantarel, Brandi L; Duncan, Alexis; Ley, Ruth E; Sogin, Mitchell L; Jones, William J; Roe, Bruce A; Affourtit, Jason P; Egholm, Michael; Henrissat, Bernard; Heath, Andrew C; Knight, Rob; Gordon, Jeffrey I

    2009-01-22

    The human distal gut harbours a vast ensemble of microbes (the microbiota) that provide important metabolic capabilities, including the ability to extract energy from otherwise indigestible dietary polysaccharides. Studies of a few unrelated, healthy adults have revealed substantial diversity in their gut communities, as measured by sequencing 16S rRNA genes, yet how this diversity relates to function and to the rest of the genes in the collective genomes of the microbiota (the gut microbiome) remains obscure. Studies of lean and obese mice suggest that the gut microbiota affects energy balance by influencing the efficiency of calorie harvest from the diet, and how this harvested energy is used and stored. Here we characterize the faecal microbial communities of adult female monozygotic and dizygotic twin pairs concordant for leanness or obesity, and their mothers, to address how host genotype, environmental exposure and host adiposity influence the gut microbiome. Analysis of 154 individuals yielded 9,920 near full-length and 1,937,461 partial bacterial 16S rRNA sequences, plus 2.14 gigabases from their microbiomes. The results reveal that the human gut microbiome is shared among family members, but that each person's gut microbial community varies in the specific bacterial lineages present, with a comparable degree of co-variation between adult monozygotic and dizygotic twin pairs. However, there was a wide array of shared microbial genes among sampled individuals, comprising an extensive, identifiable 'core microbiome' at the gene, rather than at the organismal lineage, level. Obesity is associated with phylum-level changes in the microbiota, reduced bacterial diversity and altered representation of bacterial genes and metabolic pathways. These results demonstrate that a diversity of organismal assemblages can nonetheless yield a core microbiome at a functional level, and that deviations from this core are associated with different physiological states (obese

  18. Malaysian Twin Registry.

    PubMed

    Jahanfar, Shayesteh; Jaffar, Sharifah Halimah

    2013-02-01

    The National Malaysian Twin Registry was established in Royal College of Medicine, Perak, University Kuala Lumpur (UniKL) in June 2008 through a grant provided by UniKL. The general objective is to facilitate scientific research involving participation of twins and their family members in order to answer questions of health and wellbeing relevant to Malaysians. Recruitment is done via mass media, poster, and pamphlets. We now have 266 adult and 204 children twins registered. Several research projects including reproductive health study of twins and the role of co-bedding on growth and development of children are carried out. Registry holds annual activities for twins and seeks to provide health-related information for twins. We seek international collaboration.

  19. Zygosity Differences in Height and Body Mass Index of Twins From Infancy to Old Age: A Study of the CODATwins Project.

    PubMed

    Jelenkovic, Aline; Yokoyama, Yoshie; Sund, Reijo; Honda, Chika; Bogl, Leonie H; Aaltonen, Sari; Ji, Fuling; Ning, Feng; Pang, Zengchang; Ordoñana, Juan R; Sánchez-Romera, Juan F; Colodro-Conde, Lucia; Burt, S Alexandra; Klump, Kelly L; Medland, Sarah E; Montgomery, Grant W; Kandler, Christian; McAdams, Tom A; Eley, Thalia C; Gregory, Alice M; Saudino, Kimberly J; Dubois, Lise; Boivin, Michel; Tarnoki, Adam D; Tarnoki, David L; Haworth, Claire M A; Plomin, Robert; Öncel, Sevgi Y; Aliev, Fazil; Stazi, Maria A; Fagnani, Corrado; D'Ippolito, Cristina; Craig, Jeffrey M; Saffery, Richard; Siribaddana, Sisira H; Hotopf, Matthew; Sumathipala, Athula; Rijsdijk, Fruhling; Spector, Timothy; Mangino, Massimo; Lachance, Genevieve; Gatz, Margaret; Butler, David A; Bayasgalan, Gombojav; Narandalai, Danshiitsoodol; Freitas, Duarte L; Maia, José Antonio; Harden, K Paige; Tucker-Drob, Elliot M; Kim, Bia; Chong, Youngsook; Hong, Changhee; Shin, Hyun Jung; Christensen, Kaare; Skytthe, Axel; Kyvik, Kirsten O; Derom, Catherine A; Vlietinck, Robert F; Loos, Ruth J F; Cozen, Wendy; Hwang, Amie E; Mack, Thomas M; He, Mingguang; Ding, Xiaohu; Chang, Billy; Silberg, Judy L; Eaves, Lindon J; Maes, Hermine H; Cutler, Tessa L; Hopper, John L; Aujard, Kelly; Magnusson, Patrik K E; Pedersen, Nancy L; Aslan, Anna K Dahl; Song, Yun-Mi; Yang, Sarah; Lee, Kayoung; Baker, Laura A; Tuvblad, Catherine; Bjerregaard-Andersen, Morten; Beck-Nielsen, Henning; Sodemann, Morten; Heikkilä, Kauko; Tan, Qihua; Zhang, Dongfeng; Swan, Gary E; Krasnow, Ruth; Jang, Kerry L; Knafo-Noam, Ariel; Mankuta, David; Abramson, Lior; Lichtenstein, Paul; Krueger, Robert F; McGue, Matt; Pahlen, Shandell; Tynelius, Per; Duncan, Glen E; Buchwald, Dedra; Corley, Robin P; Huibregtse, Brooke M; Nelson, Tracy L; Whitfield, Keith E; Franz, Carol E; Kremen, William S; Lyons, Michael J; Ooki, Syuichi; Brandt, Ingunn; Nilsen, Thomas Sevenius; Inui, Fujio; Watanabe, Mikio; Bartels, Meike; van Beijsterveldt, Toos C E M; Wardle, Jane; Llewellyn, Clare H; Fisher, Abigail; Rebato, Esther; Martin, Nicholas G; Iwatani, Yoshinori; Hayakawa, Kazuo; Sung, Joohon; Harris, Jennifer R; Willemsen, Gonneke; Busjahn, Andreas; Goldberg, Jack H; Rasmussen, Finn; Hur, Yoon-Mi; Boomsma, Dorret I; Sørensen, Thorkild I A; Kaprio, Jaakko; Silventoinen, Karri

    2015-10-01

    A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes. PMID:26337138

  20. A Chaotic Home Environment Accounts for the Association between Respect for Rules Disposition and Reading Comprehension: A Twin Study.

    PubMed

    Taylor, Jeanette; Hart, Sara A

    2014-10-01

    This study examined the association between socioemotional dispositions from the developmental propensity model and reading comprehension and whether those associations could be accounted for by level of chaos in the home. Data from 342 monozygotic and 333 same-sex dizygotic twin pairs age 7-13 years were used. A parent rated the twins on sympathy, respect for rules, negative emotionality, and daring and level of chaos in the twins' home. Reading comprehension was measured using a state-wide school assessment. Only respect for rules significantly and uniquely predicted reading comprehension. Biometric models indicated that respect for rules was positively associated with reading comprehension via the shared environment and home chaos accounted for a significant amount of that shared environmental variance even after controlling for family income. Children with higher respect for rules have better reading comprehension scores in school and this relationship owes partly to the level of chaos in the family home.

  1. Measurement-based method for verifying quantum discord

    NASA Astrophysics Data System (ADS)

    Rahimi-Keshari, Saleh; Caves, Carlton M.; Ralph, Timothy C.

    2013-01-01

    We introduce a measurement-based method for verifying quantum discord of any bipartite quantum system. We show that by performing an informationally complete positive operator valued measurement (IC-POVM) on one subsystem and checking the commutativity of the conditional states of the other subsystem, quantum discord from the second subsystem to the first can be verified. This is an improvement upon previous methods, which enables us to efficiently apply our method to continuous-variable systems, as IC-POVM's are readily available from homodyne or heterodyne measurements. We show that quantum discord for Gaussian states can be verified by checking whether the peaks of the conditional Wigner functions corresponding to two different outcomes of heterodyne measurement coincide at the same point in the phase space. Using this method, we also prove that the only Gaussian states with zero discord are product states; hence, Gaussian states with Gaussian discord have nonzero quantum discord.

  2. Discordant bone marrow involvement in non-Hodgkin lymphoma.

    PubMed

    Brudno, Jennifer; Tadmor, Tamar; Pittaluga, Stefania; Nicolae, Alina; Polliack, Aaron; Dunleavy, Kieron

    2016-02-25

    A discordant lymphoma occurs where 2 distinct histologic subtypes coexist in at least 2 separate anatomic sites. Histologic discordance is most commonly observed between the bone marrow (BM) and lymph nodes (LNs), where typically aggressive lymphoma is found in a LN biopsy with indolent lymphoma in a BM biopsy. Although the diagnosis of discordance relied heavily on histopathology alone in the past, the availability of flow cytometry and molecular studies have aided the identification of this entity. The true prevalence and clinical ramifications of discordance remain controversial as available data are principally retrospective, and there is therefore little consensus to guide optimal management strategies. In this review, we examine the available literature on discordant lymphoma and its outcome, and discuss current therapeutic approaches. Future studies in discordant lymphoma should ideally focus on a large series of patients with adequate tissue samples and incorporate molecular analyses. PMID:26679865

  3. Sudden change of geometric quantum discord in finite temperature reservoirs

    SciTech Connect

    Hu, Ming-Liang Sun, Jian

    2015-03-15

    We investigate sudden change (SC) behaviors of the distance-based measures of geometric quantum discords (GQDs) for two non-interacting qubits subject to the two-sided and the one-sided thermal reservoirs. We found that the GQDs defined by different distances exhibit different SCs, and thus the SCs are the combined result of the chosen discord measure and the property of a state. We also found that the thermal reservoir may generate states having different orderings related to different GQDs. These inherent differences of the GQDs reveal that they are incompatible in characterizing quantum correlations both quantitatively and qualitatively. - Highlights: • Comparable study of different distance-based geometric quantum discords. • Evolution of the geometric quantum discords in finite temperature reservoirs. • Different geometric quantum discords exhibit distinct sudden changes. • Nonunique states ordering imposed by different geometric quantum discords.

  4. Relating quantum discord with the quantum dense coding capacity

    SciTech Connect

    Wang, Xin; Qiu, Liang Li, Song; Zhang, Chi; Ye, Bin

    2015-01-15

    We establish the relations between quantum discord and the quantum dense coding capacity in (n + 1)-particle quantum states. A necessary condition for the vanishing discord monogamy score is given. We also find that the loss of quantum dense coding capacity due to decoherence is bounded below by the sum of quantum discord. When these results are restricted to three-particle quantum states, some complementarity relations are obtained.

  5. An Exploration of Shared Genetic Risk Factors Between Periodontal Disease and Cancers: A Prospective Co-Twin Study

    PubMed Central

    Arora, Manish; Weuve, Jennifer; Fall, Katja; Pedersen, Nancy L.; Mucci, Lorelei A.

    2010-01-01

    Biologic mechanisms underlying associations of periodontal disease with cancers remain unknown. The authors propose that both conditions share common genetic risk factors. They analyzed associations between baseline periodontal disease, measured by questionnaire-recorded tooth mobility, and incident cancers, identified by linkage with national registries, between 1963 and 2004 in 15,333 Swedish twins. The authors used co-twin analyses to control for familial factors and undertook analyses restricted to monozygotic twins to further control for confounding by genetic factors. They observed 4,361 cancer cases over 548,913 person-years. After adjustment for covariates, baseline periodontal disease was associated with increased risk of several cancers ranging from 15% for total cancer (proportional hazard ratio (HR) = 1.15, 95% confidence interval (CI): 1.01, 1.32) to 120% for corpus uterine cancer (HR = 2.20, 95% CI: 1.16, 4.18). Periodontal disease was also associated with increased risk of colorectal (HR = 1.62, 95% CI: 1.13, 2.33), pancreatic (HR = 2.06, 95% CI: 1.14, 3.75), and prostate (HR = 1.47, 95% CI: 1.04, 2.07) cancers. In co-twin analyses, dizygotic twins with baseline periodontal disease showed a 50% increase in total cancer risk (HR = 1.50, 95% CI: 1.04, 2.17), but in monozygotic twins this association was markedly attenuated (HR = 1.07, 95% CI: 0.63, 1.81). Similar patterns emerged for digestive tract cancers, suggesting that shared genetic risk factors may partially explain associations between periodontal disease and cancers. PMID:19969528

  6. Guidelines on Library Twinning.

    ERIC Educational Resources Information Center

    Doyle, Robert P., Comp.; Scarry, Patricia, Comp.

    This document serves as an overview of the many forms of library twinning, or formal exchanges of materials and/or staff between two institutions. Twinning can be reciprocal, but often involves a one-way arrangement whereby a library in a developing country receives a visit from a librarian of a developed country. Either way, both institutions can…

  7. 'Too much of a coincidence': identical twins with exertional heatstroke in the same race.

    PubMed

    Smith, R; Jones, N; Martin, D; Kipps, C

    2016-02-05

    This report discusses a unique case of monozygotic male twins who both collapsed with exertional heat stroke (EHS) during the same marathon in relatively cool conditions. The twins were official race pacers in a popular city marathon held in the early spring in the UK. Both recovered uneventfully due to the prompt recognition of EHS and use of aggressive cooling measures, which prevented life-threatening complications. The case illustrates that EHS is a complex illness with a possible genetic predisposition, which can occur among runners even in cooler conditions. This link is explored together with the influence of their role as race pacers and the additional backpack worn in the development of EHS.

  8. 'Too much of a coincidence': identical twins with exertional heatstroke in the same race.

    PubMed

    Smith, R; Jones, N; Martin, D; Kipps, C

    2016-01-01

    This report discusses a unique case of monozygotic male twins who both collapsed with exertional heat stroke (EHS) during the same marathon in relatively cool conditions. The twins were official race pacers in a popular city marathon held in the early spring in the UK. Both recovered uneventfully due to the prompt recognition of EHS and use of aggressive cooling measures, which prevented life-threatening complications. The case illustrates that EHS is a complex illness with a possible genetic predisposition, which can occur among runners even in cooler conditions. This link is explored together with the influence of their role as race pacers and the additional backpack worn in the development of EHS. PMID:26851253

  9. A Lower Bound of Quantum Discord for 2-Qutrit Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Qianhui; Wang, Jing; Shen, Shuqian; Li, Ming

    2016-04-01

    We study the lower bound of quantum discord for 2-qutrit systems. By computing the mutual information and the classical correlations of a class of states for 2-qutrit system, an analytical and computable lower bound of discord has been derived. By selecting different coefficients as examples, we can compute the lower bound of discord for 2-qutrit systems directly. The result can be generalized to the case of high-dimensional quantum state and will help us understand and explore the discord of the high-dimensional state.

  10. Geometry and dynamics of one-norm geometric quantum discord

    NASA Astrophysics Data System (ADS)

    Huang, Zhiming; Qiu, Daowen; Mateus, Paulo

    2016-01-01

    We investigate the geometry of one-norm geometric quantum discord and present a geometric interpretation of one-norm geometric quantum discord for a class of two-qubit states. It is found that one-norm geometric quantum discord has geometric behavior different from that described