scholarly journals Heritabilities of Apolipoprotein and Lipid Levels in Three Countries

Twin Research ◽  
2002 ◽  
Vol 5 (2) ◽  
pp. 87-97 ◽  
Author(s):  
Marian Beekman ◽  
Bastiaan T. Heijmans ◽  
Nicholas G. Martin ◽  
Nancy L. Pedersen ◽  
John B. Whitfield ◽  
...  
Keyword(s):  
Genetic Factors ◽  
Lipid Levels ◽  
Common Environment ◽  
Specific Effects ◽  
Intermediate Phenotypes ◽  
Genes And Environment ◽  
Two Samples ◽  
Australian Sample ◽  
Important Intermediate ◽  
Heritability Estimates

AbstractThis study investigated the influence of genes and environment on the variation of apolipoprotein and lipid levels, which are important intermediate phenotypes in the pathways toward cardiovascular disease. Heritability estimates are presented, including those for apolipoprotein E and AII levels which have rarely been reported before. We studied twin samples from the Netherlands (two cohorts;n= 160 pairs, aged 13–22 andn= 204 pairs, aged 34–62), Australia (n= 1362 pairs, aged 28–92) and Sweden (n= 302 pairs, aged 42–88). The variation of apolipoprotein and lipid levels depended largely on the influences of additive genetic factors in each twin sample. There was no significant evidence for the influence of common environment. No sex differences in heritability estimates for any phenotype in any of the samples were observed. Heritabilities ranged from 0.48–0.87, with most heritabilities exceeding 0.60. The heritability estimates in the Dutch samples were significantly higher than in the Australian sample. The heritabilities for the Swedish were intermediate to the Dutch and the Australian samples and not significantly different from the heritabilities in these other two samples. Although sample specific effects are present, we have shown that genes play a major role in determining the variance of apolipoprotein and lipid levels in four independent twin samples from three different countries.

scholarly journals Self-Efficacy Is Mainly Genetic, Not Learned: A Multiple-Rater Twin Study on the Causal Structure of General Self-Efficacy in Young People

2013 ◽  
Vol 16 (3) ◽  
pp. 651-660 ◽  
Author(s):  
Trine Waaktaar ◽  
Svenn Torgersen
Keyword(s):  
Young People ◽  
Self Efficacy ◽  
Genetic Factors ◽  
Causal Structure ◽  
Population Based ◽  
Theoretical Assumption ◽  
Common Environment ◽  
Specific Effects ◽  
Environmental Causes ◽  
General Self Efficacy

Social learning theory postulates that self-efficacy is learned through the person's interaction with his/her physical and social environment. In this genetically informative, population-based, multi-informant study of 1,394 adolescent twin pairs, self-efficacy was modeled as one latent psychometric self-efficacy factor with genetic and environmental effects common to all informants, as well as for effects specific for each informant. The results showed that 75% of variation in self-efficacy was due to genetic factors. Non-shared environmental causes explained the remaining 25% of the variance in the latent factor, with no effect of common environment. Some informant-specific effects were also found. The present study challenges the theoretical assumption of learning as the dominant etiological factor behind self-efficacy in young people.

Distribution and Heritability of Recurrent Ear Infections

1997 ◽  
Vol 106 (8) ◽  
pp. 624-632 ◽  
Author(s):  
Kari J. Kvaerner ◽  
Jennifer R. Harris ◽  
Kristian Tambs ◽  
Per Magnus
Keyword(s):  
Structural Equation ◽  
Genetic Factors ◽  
Age Of Onset ◽  
Population Based ◽  
Equation Modeling ◽  
Relative Contribution ◽  
Genes And Environment ◽  
Ear Infections ◽  
The Mean ◽  
Familial Environment

The distribution of recurrent ear infections was obtained from a population-based sample of 2,750 pairs of Norwegian twins born between 1967 and 1974. The lifetime prevalence of self-reported recurrent ear infections was 8.9%, with a significant predominance of female cases. The mean age of onset was 4.2 years, with a gradual decrease in occurrence from 2 to 7 years of age. Among monozygotic pairs, the rate of tetrachoric correlation between co-twins was almost identical in males (0.73, SE 0.08) and females (0.74, SE 0.06), but among the dizygotic pairs the correlation was clearly higher in males (0.53, SE 0.12) than in females (0.20, SE 0.12). The value in the unlike-sexed dizygotic twins (0.25, SE 0.05) was intermediate to that of the like-sexed male and female dizygotic pairs. The relative contribution of genes and environment to variability in the predisposition to develop otitis media was estimated by means of structural equation modeling. Variation in liability to ear infections was mainly explained by additive genetic and dominance factors in females, for whom heritability was estimated at 74%. The remaining 26% of the variation in liability was explained by individual environmental factors. In males, 45% of the variation could be accounted for by genetic factors, 29% by common familial environment, and the remaining 26% by individual environmental effects.

Development of Eating Behaviors Among Children and Adolescents

PEDIATRICS ◽  
1998 ◽  
Vol 101 (Supplement_2) ◽  
pp. 539-549 ◽  
Author(s):  
Leann L. Birch ◽  
Jennifer O. Fisher
Keyword(s):  
Individual Differences ◽  
Energy Intake ◽  
Genetic Factors ◽  
Feeding Practices ◽  
Individual Development ◽  
Preventive Interventions ◽  
Child Feeding ◽  
Preschool Period ◽  
Child Feeding Practices ◽  
Genes And Environment

The prevalence of obesity among children is high and is increasing. We know that obesity runs in families, with children of obese parents at greater risk of developing obesity than children of thin parents. Research on genetic factors in obesity has provided us with estimates of the proportion of the variance in a population accounted for by genetic factors. However, this research does not provide information regarding individual development. To design effective preventive interventions, research is needed to delineate how genetics and environmental factors interact in the etiology of childhood obesity. Addressing this question is especially challenging because parents provide both genes and environment for children. An enormous amount of learning about food and eating occurs during the transition from the exclusive milk diet of infancy to the omnivore's diet consumed by early childhood. This early learning is constrained by children's genetic predispositions, which include the unlearned preference for sweet tastes, salty tastes, and the rejection of sour and bitter tastes. Children also are predisposed to reject new foods and to learn associations between foods' flavors and the postingestive consequences of eating. Evidence suggests that children can respond to the energy density of the diet and that although intake at individual meals is erratic, 24-hour energy intake is relatively well regulated. There are individual differences in the regulation of energy intake as early as the preschool period. These individual differences in self-regulation are associated with differences in child-feeding practices and with children's adiposity. This suggests that child-feeding practices have the potential to affect children's energy balance via altering patterns of intake. Initial evidence indicates that imposition of stringent parental controls can potentiate preferences for high-fat, energy-dense foods, limit children's acceptance of a variety of foods, and disrupt children's regulation of energy intake by altering children's responsiveness to internal cues of hunger and satiety. This can occur when well-intended but concerned parents assume that children need help in determining what, when, and how much to eat and when parents impose child-feeding practices that provide children with few opportunities for self-control. Implications of these findings for preventive interventions are discussed.

Transgressive segregation and maternal genetic effects of non–target site fluazifop-P-butyl tolerance in Zoysia spp.

Weed Science ◽  
2019 ◽  
Vol 67 (05) ◽  
pp. 504-509
Author(s):  
Wenwen Liu ◽  
Kevin E. Kenworthy ◽  
Gregory E. MacDonald ◽  
J. Bryan Unruh ◽  
Laurie E. Trenholm ◽  
...  
Keyword(s):  
Genetic Factors ◽  
Breeding Population ◽  
Transgressive Segregation ◽  
Target Site ◽  
Multiple Traits ◽  
Intermediate Phenotypes ◽  
Wide Range ◽  
Genetic Mechanisms ◽  
Tolerant Line ◽  
Biomass Reduction

AbstractZoysia germplasm exhibit different levels of sensitivity to fluazifop-P-butyl, but the genetic factors responsible for such differences are unknown. Segregation patterns of the fluazifop-P-butyl tolerance trait were studied under greenhouse conditions. In total, 244 F1 lines were generated from multiple crosses between the tolerant line 5337-2 (non–target site tolerance) and three more-sensitive lines (123, 252, and 5330-23). Progeny segregation showed that fluazifop-P-butyl tolerance within zoysiagrass (Zoysia spp.) is expressed as a quantitative trait with a wide range of intermediate phenotypes between parental phenotypes. Transgressive segregation was extensive and largely favored susceptibility in most families, but was especially evident for 5337-2 × 123 and 5337-2 × 5330-23. The segregation patterns for biomass reduction and percent injury were different within reciprocal crosses and among three different family crosses. Reciprocal effects were observed in growth reduction for 5337-2 × 5330-23, in percent injury at 3 wk after the treatment (WAT), and for 5337-2 × 252 at 6 WAT. This indicated that fluazifop-P-butyl tolerance was not completely controlled by nuclear genetic factors in 5337-2 and maternal/cytoplasmic inheritance was also partially responsible. These results suggested that fluazifop-P-butyl tolerance may be attributed to multiple genetic mechanisms, which could present a challenge for future breeding efforts because of the difficulty of fixing multiple traits within a breeding population.

Twins Studies in Economics

2015 ◽  
pp. 384-404 ◽  
Author(s):  
Jere Behrman
Keyword(s):  
Fixed Effects ◽  
Family Background ◽  
Variance Decomposition ◽  
Common Environment ◽  
Genetic Sequencing ◽  
Investment In Children ◽  
Heritability Estimates ◽  
Mz Twins

This chapter describes strengths and limitations of three twins methods developed in economics: control for unobserved genetic and family background endowments using monozygotic (MZ) twins fixed effects (FE) to estimate e.g. impacts of schooling on wages, health, and other outcomes; estimation of key parameters in intrafamilial models of investment in children using MZ and dizygotic (DZ) twins; and investigation of familial responses to fertility shocks within the quantity-quality fertility model using MZs and DZs. It also describes strengths and limitations of a fourth twins method used most widely outside of economics: variance decomposition of phenotypes into genetic and environmental components to obtain heritability estimates with additive genetics, common environment and unique environment (ACE) models using MZs and DZs. The chapter concludes that the first three twins methods remain valuable for learning about important empirical parameters in economics despite development of genetic sequencing. The fourth method is less useful in economics.

scholarly journals Phenotypic, Genetic, and Environmental Properties of the Portrait Values Questionnaire

2008 ◽  
Vol 11 (5) ◽  
pp. 531-537 ◽  
Author(s):  
Julie Aitken Schermer ◽  
N. T. Feather ◽  
Gu Zhu ◽  
Nicholas G. Martin
Keyword(s):  
Environmental Factors ◽  
Genetic Factors ◽  
Genetic Component ◽  
Environmental Properties ◽  
Value Types ◽  
Heritability Estimates ◽  
Almost All ◽  
Environmental Level

AbstractThe purpose of the present study was to examine the 10 value types from the Portrait Values Questionnaire (PVQ; Schwartz et al., 2001) both at the phenotypic (observed) level as well as the genetic and environmental level. Australian twins (N= 695) completed the PVQ as part of a larger questionnaire battery. Nine of the value types were found to have a genetic component with heritability estimates ranging from 10.8% for power to 38% for conformity. The achievement scale was best explained by environmental factors. The interscale correlations were found to range from –.02 to .70 at the phenotypic level. Of these 45 correlations, 16 were found to be explained by overlapping genetic factors and almost all (41) were found to have significant unique environment correlations.

scholarly journals Protocol for a longitudinal twin birth cohort study to unravel the complex interplay between early-life environmental and genetic risk factors in health and disease: the Chongqing Longitudinal Twin Study (LoTiS)

BMJ Open ◽  
2018 ◽  
Vol 8 (2) ◽  
pp. e017889 ◽  
Author(s):  
Chao Tong ◽  
Li Wen ◽  
Yinyin Xia ◽  
Pamela Leong ◽  
Lan Wang ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Twin Study ◽  
Twin Studies ◽  
Birth Cohort Study ◽  
Clinical Trial Registry ◽  
Time Points ◽  
Intermediate Phenotypes ◽  
Genes And Environment ◽  
Depth Analysis ◽  
Longitudinal Twin Study

IntroductionNon-communicable diseases (NCD) now represent the major burden of adverse health in most countries. It is clear that much of the risk of such conditions begins very early in life, potentially in utero. Given their complex aetiology, an understanding of the origins of NCD requires an in-depth analysis of the interplay between genetic variation and environment, preferably over time. For decades, twin studies have played a key role in understanding such traits. Their strength lies in the ability to disentangle genetic and environmental factors that contribute to a phenotype. This is done by comparing genetically identical monozygotic (MZ) with dizygotic twins, who share on average 50% of genetic variation, or by comparing MZ twins within a pair. This study aims to determine the relative contributions of genes and environment to early-onset intermediate phenotypes related to later adult onset disease (such as growth and neurodevelopment) and to identify specific biomarkers and time points for emergence of phenotypes from infancy, largely independent of underlying genetic factors.Methods/designThe Chongqing Longitudinal Twin Study (LoTiS) will recruit 300 women pregnant with twins, enriched for MZ pregnancies, with follow-up to 3 years of age. Data collection will be undertaken at key time points in gestation (×3), at delivery and postnatally (×9). Maternal and infant biospecimens including blood, urine, hair, nails and buccal swabs along with measures such as fetal scans and body measurements will be collected. Additional information from questionnaires and medical records includes pregnancy, diet, sociodemographics, maternal stress, and infant growth and neurodevelopment.Ethics and disseminationThis study has been approved by the Ethics Committee of Chongqing Medical University (record no: 201530) and has been registered with the Chinese Clinical Trial Registry (registry no: ChiCTR-OOC-16008203). Results of the recruitment and all subsequent analyses will be submitted for publication in peer-reviewed journals.Trial registration numberChiCTR-OOC-16008203; Results.

Analysis of lifetime performance in Karan Fries Cattle

2017 ◽  
Author(s):  
Shakti Kant Dash ◽  
A. K. Gupta ◽  
Manoj M. ◽  
Virender Kumar ◽  
Pushp Raj Shivhre ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Genetic Factors ◽  
Gene Action ◽  
Production Traits ◽  
Additive Gene Action ◽  
Reproduction Traits ◽  
Additive Gene ◽  
Heritability Estimates ◽  
Fertility Traits ◽  
Karan Fries

Present investigation includes the study of the effect of genetic and non-genetic factors and estimation of genetic parameters with respect to lifetime production and reproduction traits of Karan Fries cattle. Data consisted of a total of 5878 lactation records on 1988 cows over a period of 32years (1981 to 2012), maintained at ICAR-NDRI, Karnal. Overall least-squares means for LT2 (kg), LT3 (kg), LT4 (kg), LT5 (kg), ALTMY (kg), PL (days), HL (days), MY/PL (kg/day), MY/HL (kg/day), BE (%), LTDPR were found to be 7907.57±121.21, 12714.68±226.90, 17720.46±338.52, 22282.97±529.00, 15946.45±256.85, 1510.36±21.46, 2571.25±27.31, 9.87±0.11, 5.70±0.07, 89.30±0.84, 0.37±1.22, respectively. Both production and fertility lifetime traits were significantly affected by different factors viz. season of birth, period of birth, genetic group and normal lactations completed. LSANOVA heritability estimates of LT2, LT3, LT4, ALTMY, MY/PL, MY/HL, BE, LTDPR, PL and HL were 0.29±0.09, 0.30±0.12, 0.29±0.17, 0.17±0.08, 0.21±0.08, 0.27±0.09, 0.20±0.08, 0.09±0.10, 0.10±0.08 and 0.03±0.06, respectively. Heritability estimates indicated that lifetime fertility traits were less affected by additive gene action. Genetic correlation estimates indicated unfavourable positive correlation between lifetime fertility and production traits.

Depression and Somatic Symptoms: A Cross-Cultural Study

1994 ◽  
Vol 28 (2) ◽  
pp. 274-278 ◽  
Author(s):  
H. Marmanidis ◽  
G. Holme ◽  
R. J. Hafner
Keyword(s):  
Factor Analysis ◽  
Depressive Disorder ◽  
Research Team ◽  
Function Analysis ◽  
Somatic Symptoms ◽  
Cross Cultural ◽  
Somatic Complaints ◽  
Cross Cultural Study ◽  
Two Samples ◽  
Australian Sample

The study was carried out by the same research team in two metropolitan hospitals, one in Greece (N = 60) and one in Australia (N q 56). Subjects comprised patients consecutively admitted with a DSM-III-R diagnosis of depressive disorder, all of whom completed questionnaire measures of depression, anxiety and somatic symptoms. Clinical concepts and practices in the two hospitals were very similar. Overall levels of depression, anxiety and somatic symptoms in the two samples were almost identical, but there were differences in the pattern of somatic complaints: Greeks scored significantly higher on dizziness, paraesthesiae and masticatory spasms, and Australians scored significantly higher on drowsiness, hypersomnia and non-refreshing sleep, with the latter two items being the best discriminators of the two samples using discriminant function analysis. These findings, combined with factor analysis, suggested that symptoms associated with hyperventilation in the Greek sample, and with sleep disturbance in the Australian sample, explained most of the differences between them.

scholarly journals Heritability of life satisfaction in adults: a twin-family study

2005 ◽  
Vol 35 (11) ◽  
pp. 1581-1588 ◽  
Author(s):  
J. H. STUBBE ◽  
D. POSTHUMA ◽  
D. I. BOOMSMA ◽  
E. J. C. De GEUS
Keyword(s):  
Life Satisfaction ◽  
Individual Differences ◽  
Genetic Factors ◽  
Satisfaction With Life ◽  
Well Being ◽  
Satisfaction With Life Scale ◽  
Subjective Well Being ◽  
Dutch Version ◽  
Sibling Pairs ◽  
Genes And Environment

Background. Subjective well-being (SWB) can be partitioned into the components life satisfaction and affect. Research on factors influencing these components of well-being has mainly focused on environmental characteristics. The aim of this study was to investigate the relative contribution of genes and environment to individual differences in life satisfaction in a large sample of Dutch twins and their singleton siblings.Method. Life satisfaction of 5668 subjects registered with The Netherlands Twin Registry (NTR) was measured with a Dutch version of the self-reported Satisfaction with Life Scale. An extended twin design was used to obtain correlations in life satisfaction scores for monozygotic twins, dizygotic twins and sibling pairs and to estimate the contribution of genes and environment to the variation in life satisfaction.Results. No differences between males and females were found in the mean level of life satisfaction. Broad-sense heritability was 38%. Non-additive genetic factors explained all or most of the genetic influences. The remaining 62% of the variance in life satisfaction could be attributed to unique environmental factors, both persistent and transitory, plus measurement error.Conclusions. Individual differences in life satisfaction are determined in part by genetic factors that are largely or entirely non-additive in nature.

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