Search results for "heritability"
showing 10 items of 141 documents
Genetic variation and urine cadmium levels: ABCC1 effects in the Strong Heart Family Study
2021
Abstract Genetic effects are suspected to influence cadmium internal dose. Our objective was to assess genetic determinants of urine cadmium in American Indian adults participating in the Strong Heart Family Study (SHFS). Urine cadmium levels and genotyped short tandem repeat (STR) markers were available on 1936 SHFS participants. We investigated heritability, including gene-by-sex and smoking interactions, and STR-based quantitative trait locus (QTL) linkage, using a variance-component decomposition approach, which incorporates the genetic information contained in the pedigrees. We also used available single nucleotide polymorphisms (SNPs) from Illumina’s Metabochip and custom panel to ass…
Genetic and environmental influences on longitudinal changes in leisure-time physical activity from adolescence to young adulthood.
2013
The aim of this study was to estimate genetic and environmental influences on the longitudinal evolution of leisure-time physical activity habits from adolescence to young adulthood. Data were gathered at four time points, at mean ages 16.2, 17.1, 18.6, and 24.5 years. At baseline, the sample comprised 5,216 monozygotic and dizygotic twins, born 1975–1979, and, at the last follow-up point, of 4,531 monozygotic and dizygotic twins. Physical activity volume was assessed as frequency of leisure-time physical activity and participants were categorized into three groups: inactive, moderately active, and active. Genetic and environmental influences were estimated using a multivariate, longitudina…
Genetic and environmental contributions to serum ascorbic acid concentrations: the Stanislas Family Study.
2006
Although numerous environmental factors are documented to influence serum ascorbic concentrations, little is known about the genetic versus environmental contributions to variation of this trait. The aim of this study was to estimate family correlation and, additive genetic heritability and household effects in a variance component analysis for serum ascorbic acid concentrations. In a sample of ninety French families, information was obtained regarding serum ascorbic acid concentrations, usual dietary intake, lifestyle, and other related covariates. Spouse, parent –offspring and offspring –offspring significant correlation coefficients for serum ascorbic acid concentrations, adjusted for ag…
A genetic basis for IFN-gamma production and T-bet expression in humans.
2005
Abstract Th1 and Th2 cytokines secreted by polarized effector T cells play a pivotal role in the development of autoimmune and allergic diseases. However, the genetic basis of cytokine production by T lymphocytes in humans is poorly understood. In this study, we investigated the genetic contribution to cytokine production and regulation of T cell-specific transcription factors in a prospective twin study. We found a substantial genetic contribution to the production of Th1 cytokines such as IFN-γ and TNF-α with heritabilities of 0.85 (95% confidence intervals, 0.74–0.95) and 0.72 (0.50–0.93), respectively, whereas no genetic influence on production of the Th2 signature cytokine IL-4 was obs…
Contribution of genetic and environmental factors to variation in body compartments--a twin study in adults.
2004
This study aimed at analyzing the contribution of genetic and environmental factors on phenotypic variation of various traits of body composition. Subjects were 30 same-sexed pairs of twins including 20 monozygous (MZ) and 10 dizygous (DZ) pairs, aged 19-62 years. Zygosity was determined by DNA typing and morphological diagnosis. Body composition parameters (fat mass FM, lean body mass LBM, body cell mass BCM, extracellular mass ECM, total body water TBW, extracellular water ECW, and intracellular water ICW) were estimated by tetrapolar bioelectrical impedance analysis. Potential environmental factors influencing body composition (number of children, sporting activity and smoking behaviour)…
Differential genetic determination of immune responsiveness to hepatitis B surface antigen and to hepatitis A virus: a vaccination study in twins.
2002
Summary Background The course of viral hepatitis is thought to be affected by genetic host variability and, in particular, by genes of the major histocompatibility locus. Hepatitis A and B vaccination is a useful model to study the effect of host factors on the immune response to viral antigens. We aimed to assess the heritability of the HBsAg (anti-HBs) and anti-hepatitis A virus (anti-HAV) immune response and to estimate the effect of the HLA-DRB1 locus and other genetic loci unlinked to HLA. Methods We did an open prospective study and vaccinated 202 twin pairs with a combined recombinant HBsAg/inactivated hepatitis A vaccine. We measured antibodies to HBsAg and HAV and determined HLA-DR…
Genetic architecture of motives for leisure-time physical activity: a twin study
2017
The aim of this study was to estimate the contribution of genetic and environmental influences on motives for engaging in leisure‐time physical activity. The participants were obtained from the FinnTwin16 study. A modified version of the Recreational Exercise Motivation Measure was used to assess the motives for leisure‐time physical activity in 2542 twin individuals (mean age of 34.1 years). Linear structural equation modeling was used to investigate the genetic and environmental influences on motive dimensions. The highest heritability estimates were found for the motive dimensions of “enjoyment” [men 33% (95% CI 23–43%), women 53% (95% CI 45–60%)] and “affiliation” [men 39% (95% CI 0.28–…
Nine Loci for Ocular Axial Length Identified through Genome-wide Association Studies, Including Shared Loci with Refractive Error
2013
Refractive errors are common eye disorders of public health importance worldwide. Ocular axial length (AL) is the major determinant of refraction and thus of myopia and hyperopia. We conducted a meta-analysis of genome-wide association studies for AL, combining 12,531 Europeans and 8,216 Asians. We identified eight genome-wide significant loci for AL (RSPO1, C3orf26, LAMA2, GJD2, ZNRF3, CD55, MIP, and ALPPL2) and confirmed one previously reported AL locus (ZC3H11B). Of the nine loci, five (LAMA2, GJD2, CD55, ALPPL2, and ZC3H11B) were associated with refraction in 18 independent cohorts (n = 23,591). Differential gene expression was observed for these loci in minus-lens-induced myopia mouse …
Genetic and environmental contributions to plasma C-reactive protein and interleukin-6 levels--a study in twins.
2006
Elevated baseline levels of acute-phase proteins such as C-reactive protein (CRP) or cytokines like interleukin-6 (IL-6) are known risk factors for atherosclerosis and cardiovascular disease (CVD) events. However, until today, there is only controversial information about the contribution of genetic and environmental factors. Therefore, we performed an open prospective study in 108 monozygotic (MZ) and 60 same-sex dizygotic (DZ) twin pairs to analyse the genetic and environmental contributions to plasma CRP and IL-6 levels. Heritability of IL-6 was 0.61, indicating that plasma IL-6 levels are to a major part influenced by genetic determinants; however, for CRP, heritability was only 0.22, p…
Genetic and Environmental Effects on the Individual Variation and Continuity of Participation in Diverse Physical Activities
2021
INTRODUCTION Participation in diverse physical activities has beneficial health effects. However, little is known on how genetic and environmental factors affect this trait. Thus, we examined to what extent these factors explain participation in diverse leisure-time physical activities from late adolescence to adulthood using a twin study design. METHODS The participants were Finnish twins who reported their participation in diverse leisure-time physical activities at ages 17 (n = 5429) and 34 yr (n = 4246). The number of physical activities engaged in was analyzed using applications of structural linear modeling for twin data. RESULTS On average, the total number of physical activities eng…