Twin research : the official journal of the International Society for Twin Studies最新文献

{"title":"Profiling Gene Expression in Whole Blood Samples Following an In-Vitro Challenge","authors":"S. Spijker, J. van de Leemput, Chantal Hoekstra, D. Boomsma, A. Smit","doi":"10.1375/twin.7.6.564","DOIUrl":"https://doi.org/10.1375/twin.7.6.564","url":null,"abstract":"Abstract Genomics tools (gene- and protein-expression studies) can be used to find possible target genes involved in a quantifiable trait or disease state. However in many instances, cells and tissues directly involved in the trait's expression, for example, brain tissue, are not amenable for gene expression analysis. Whole blood cells share a molecular make-up for cellular communication and gene regulation systems with many other cell types, for example, neuronal cells, and have the advantage of being very accessible for gene profiling. We investigated the feasibility of nationwide blood sample collection for lymphocyte RNA isolation and real-time PCR analysis to quantify genomic responses. We tested several designs for blood collection and storage: blood sampling in PAXgene blood collection tubes and storage at −20°C, blood sampling in heparin tubes and decanting the samples (with or without in-vitro stimulus) into either PAXgene blood collection tubes and storage at −20°C, or polypropylene tubes followed by snap-freezing and storage at −80°C. The latter procedure is the best cost-wise when only small amounts of total RNA are needed for downstream applications. Lymphocyte gene expression studies are most likely hampered by the quality of isolated RNA rather than the sampling method. We show that large-scale nationwide sample collections did not alter RNA quality or gene expression levels when compared to sampling and processing in a more controlled way. To this end, we present an optimized protocol for easy and standardized isolation of high quality RNA using the PAXgene isolation kit. Based on these results, we suggest that whole blood genomic data can be used as a genomic probe in experimental and clinical research.","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 1","pages":"564 - 570"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/twin.7.6.564","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66608790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Genetics of Middle-Age Spread in Middle-Class Males","authors":"J. Romeis, J. Grant, V. Knopik, N. Pedersen, A. Heath","doi":"10.1375/twin.7.6.596","DOIUrl":"https://doi.org/10.1375/twin.7.6.596","url":null,"abstract":"Abstract This study provides findings to assist in identifying factors that contribute to the current clinical and public health debate of the obesity epidemic. The study examined the genetics of adult-onset weight change in middle-aged male—male twins controlling for weight in early adulthood, lifetime history of tobacco use and alcohol dependence, and aimed to estimate the proportion of genetic factors that influence weight change between early adulthood and middle age in white middle-class males. The study was a classic longitudinal twin design and used Body Mass Index (BMI) for three waves of data collection from the Vietnam Era Twin Registry — induction physicals (∼ 1968), 1987 and 1990 — or periods corresponding between young adulthood and middle age. Univariate heritability estimates for BMI at all three data periods were conducted as well as a Cholesky longitudinal genetic analysis for weight change controlling for BMI at military induction, smoking and alcohol use. Frequency data indicated that the sample was on average classified as normal BMI in their 20s; but BMI gradually increased during the next twenty years. Univariate data for each data period indicated that additive genetic factors accounted for between 63% and 69% of total variance in BMI. The Cholesky longitudinal genetic analysis of BMI87 and BMI90, controlling for BMI at military induction, indicated that more than half of the change in BMI from early adulthood to middle age remains heritable. No shared environmental factors were identified, thus the remainder of the variance was accounted for by nonshared, or unique, environmental factors and error. The data analysis suggests that treatments and public health interventions need to recognize the magnitude of genetic factors if short-term and long-term interventions are to be effective.","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 1","pages":"596 - 602"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/twin.7.6.596","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66608839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Influences on Vulnerability to, and Protective Factors for, Adolescent Drinking","authors":"E. Siewert, M. Stallings, J. Hewitt","doi":"10.1375/twin.7.6.617","DOIUrl":"https://doi.org/10.1375/twin.7.6.617","url":null,"abstract":"Abstract Using behavioral genetic analyses, we investigated and present a possible relationship between adolescent alcohol use and six domains of common problem behaviors in a community-based sample of 633 twin pairs who were under the legal drinking age of 21 (mean age = 15.0 years). The underlying etiology of the six problem behavioral domains, classified as conduct problems, hyperactivity, school problems, low self-esteem, neuroticism, and social withdrawal, was previously described (Siewert et al., 2003) as two heritable and genetically distinct dimensions of problem behavior. We took the two best-fitting models from that study (one that proposed a generalized behavior problem factor along with an internalizing behavior factor, and one that proposed an externalizing behavior factor along with an internalizing behavior factor) and extended the analyses in this study to include an index of alcohol use. Our results suggest that there is a strong genetic relationship between adolescent alcohol use and a broad spectrum of both externalizing and internalizing behavioral problems. The individual who seems to be at risk for either generalized or specifically externalizing behavioral problems is also at risk for adolescent alcohol use. However, the individual who exhibits internalizing problem behaviors appears to be protected from adolescent alcohol use. We propose that adolescent alcohol consumption needs to be understood in the context of these genetically influenced externalizing and internalizing propensities.","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 1","pages":"617 - 625"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/twin.7.6.617","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66608927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The genetics of middle-age spread in middle-class males.","authors":"James C Romeis,&nbsp;Julia D Grant,&nbsp;Valerie S Knopik,&nbsp;Nancy L Pedersen,&nbsp;Andrew C Heath","doi":"10.1375/1369052042663896","DOIUrl":"https://doi.org/10.1375/1369052042663896","url":null,"abstract":"<p><p>This study provides findings to assist in identifying factors that contribute to the current clinical and public health debate of the obesity epidemic. The study examined the genetics of adult-onset weight change in middle-aged male-male twins controlling for weight in early adulthood, lifetime history of tobacco use and alcohol dependence, and aimed to estimate the proportion of genetic factors that influence weight change between early adulthood and middle age in white middle-class males. The study was a classic longitudinal twin design and used Body Mass Index (BMI) for three waves of data collection from the Vietnam Era Twin Registry--induction physicals (approximately 1968), 1987 and 1990--or periods corresponding between young adulthood and middle age. Univariate heritability estimates for BMI at all three data periods were conducted as well as a Cholesky longitudinal genetic analysis for weight change controlling for BMI at military induction, smoking and alcohol use. Frequency data indicated that the sample was on average classified as normal BMI in their 20s; but BMI gradually increased during the next twenty years. Univariate data for each data period indicated that additive genetic factors accounted for between 63% and 69% of total variance in BMI. The Cholesky longitudinal genetic analysis of BMI87 and BMI90, controlling for BMI at military induction, indicated that more than half of the change in BMI from early adulthood to middle age remains heritable. No shared environmental factors were identified, thus the remainder of the variance was accounted for by nonshared, or unique, environmental factors and error. The data analysis suggests that treatments and public health interventions need to recognize the magnitude of genetic factors if short-term and long-term interventions are to be effective.</p>","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 6","pages":"596-602"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/1369052042663896","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25037054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twin study summaries.","authors":"Nancy L Segal","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 6","pages":"676-7, 679"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25041663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Why twins fascinate.","authors":"Nancy L Segal","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 6","pages":"677-9"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25041664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of censoring on parameter estimates and power in genetic modeling.","authors":"Eske M Derks,&nbsp;Conor V Dolan,&nbsp;Dorret I Boomsma","doi":"10.1375/1369052042663832","DOIUrl":"https://doi.org/10.1375/1369052042663832","url":null,"abstract":"<p><p>Genetic and environmental influences on variance in phenotypic traits may be estimated with normal theory Maximum Likelihood (ML). However, when the assumption of multivariate normality is not met, this method may result in biased parameter estimates and incorrect likelihood ratio tests. We simulated multivariate normal distributed twin data under the assumption of three different genetic models. Genetic model fitting was performed in six data sets: multivariate normal data, discrete uncensored data, censored data, square root transformed censored data, normal scores of censored data, and categorical data. Estimates were obtained with normal theory ML (data sets 1-5) and with categorical data analysis (data set 6). Statistical power was examined by fitting reduced models to the data. When fitting an ACE model to censored data, an unbiased estimate of the additive genetic effect was obtained. However, the common environmental effect was underestimated and the unique environmental effect was overestimated. Transformations did not remove this bias. When fitting an ADE model, the additive genetic effect was underestimated while the dominant and unique environmental effects were overestimated. In all models, the correct parameter estimates were recovered with categorical data analysis. However, with categorical data analysis, the statistical power decreased. The analysis of L-shaped distributed data with normal theory ML results in biased parameter estimates. Unbiased parameter estimates are obtained with categorical data analysis, but the power decreases.</p>","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 6","pages":"659-69"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/1369052042663832","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24867510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Twin paternity.","authors":"Nancy L Segal","doi":"10.1375/1369052042663779","DOIUrl":"https://doi.org/10.1375/1369052042663779","url":null,"abstract":"<p><p>An unusual case of uncertain twin paternity is presented. New research on inbred strains of mice may hold important clues for paternity testing of twins in the future. Next, four recent twin studies examining selected topics in autism, color perception, language development and high-order pregnancy risk are reviewed. Finally, several unusual twin-related situations are variously considered with respect to their research significance and practical applications.</p>","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 6","pages":"675, 679"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/1369052042663779","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"24867512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Association Tests of Immune Responses to Antigens of Mycobacterium Tuberculosis: A Study of Twins in West Africa","authors":"Amanda Wiart, A. Jepson, W. Banya, S. Bennett, H. Whittle, N. Martin, A. Hill","doi":"10.1375/twin.7.6.578","DOIUrl":"https://doi.org/10.1375/twin.7.6.578","url":null,"abstract":"Abstract There is now considerable evidence that host genetic factors are important in determining the outcome of infection with Mycobacterium tuberculosis (MTB). The aim of this study was to assess the role of several candidate genes in the variation observed in the immune responses to MTB antigens. In-vitro assays of T-cell proliferation, an in-vivo intradermal delayed hypersensitivity response; cytokine and antibody secretions to several mycobacterial peptide antigens were assessed in healthy, but exposed, West African twins. Candidate gene polymorphisms were typed in the NRAMP1, Vitamin D receptor, IL10, IL4, IL4 receptor and CTLA-4 genes. Variants of the loci IL10 (−1082 G/A), CTLA-4 (49 A/G) and the IL4 receptor (128 A/G) showed significant associations with immune responses to several antigens. T-cell proliferative responses and antibody responses were reduced, TNF-α responses were increased for subjects with the CTLA-4 G allele. The T-cell proliferative responses of subjects with IL10 GA and GG genotypes differed significantly. IL4 receptor AG and GG genotypes also showed significant differences in their T-cell proliferative responses to MTB antigens. These results yield a greater understanding of the genetic mechanisms that underlie the immune responses in tuberculosis and have implications for the design of therapeutic interventions.","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 1","pages":"578 - 588"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/twin.7.6.578","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66608822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic Study of the Height and Weight Process During Infancy","authors":"P. van Dommelen, M. D. de Gunst, A. van der Vaart, D. Boomsma","doi":"10.1375/twin.7.6.607","DOIUrl":"https://doi.org/10.1375/twin.7.6.607","url":null,"abstract":"Abstract Longitudinal height and weight data from 4649 Dutch twin pairs between birth and 2.5 years of age were analyzed. The data were first summarized into parameters of a polynomial of degree 4 by a mixed-effects procedure. Next, the variation and covariation in the parameters of the growth curve (size at one year of age, growth velocity, deceleration of growth, rate of change in deceleration [i.e., jerk] and rate of change in jerk [i.e., snap]) were decomposed into genetic and nongenetic sources. Additionally, the variation in the estimated size at birth and at 2 years of age interpolated from the polynomial was decomposed into genetic and nongenetic components. Variation in growth was best characterized by a genetic model which included additive genetic, common environmental and specific environmental influences, plus effects of gestational age. The effect of gestational age was largest for size at birth, explaining 39% of the variance. The differences between monozygotic and dizygotic twin correlations were largest for size at 1 and 2 years of age and growth velocity of weight, which suggests that these parameters are more influenced by heritability than size at birth, deceleration and jerk. The percentage of variance explained by additive genetic influences for height at 2 years of age was 52% for females and 58% for males. For weight at 2 years of age, heritability was approximately 58% for both sexes. Variation in snap height for males was also mainly influenced by additive genetic factors, while snap for females was influenced by both additive genetic and common environmental factors. The correlations for the additive genetic and common environmental factors for deceleration and snap are large, indicating that these parameters are almost entirely under control of the same additive genetic and common environmental factors. Female jerk and snap, and also female height at birth and height at 2 years of age, are mostly under control of the same additive genetic factor.","PeriodicalId":75270,"journal":{"name":"Twin research : the official journal of the International Society for Twin Studies","volume":"7 1","pages":"607 - 616"},"PeriodicalIF":0.0,"publicationDate":"2004-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1375/twin.7.6.607","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66608890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}