Genetic Influences on Hallux Valgus in Koreans: The Healthy Twin Study

2014 ◽  
Vol 17 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Chang-Hyung Lee ◽  
Sooji Lee ◽  
HyoJeong Kang ◽  
Da-Eun Jung ◽  
Yun-Mi Song ◽  
...  
Keyword(s):  
Hallux Valgus ◽  
Twin Study ◽  
Genetic Factors ◽  
Weight Bearing ◽  
Monozygotic Twin ◽  
Population Based ◽  
Genetic Influences ◽  
Relative Importance ◽  
Radiographic Assessment ◽  
Anterior Posterior

Hallux valgus (HV) is a common foot deformity of multifactorial etiology, but knowledge about the relative importance of genetics and environments on HV has been limited. In order to estimate genetic influences on HV, 1,265 adults, including 175 monozygotic twin (MZ) pairs, 31 dizygotic twin (DZ) pairs, and 853 first-degree singleton family members of the twins were included from the Healthy Twin study, a population-based twin-family cohort in Korea. All participants underwent foot examination and weight-bearing radiographic assessment (anterior-posterior and lateral) in addition to a general health survey. Of the subjects, 208 (16.4%) were classified as HV (as HV angle >20°). The genetic influence on HV was estimated to be substantial; the heritability of HV was 0.51 (95% CI 0.42–0.59) and the heritability of HV angle was 0.47 (0.38–0.56), while contributions from shared environmental effects were negligible. These findings suggest that genetic factors play an important role in determining HV deformity.

scholarly journals Conceptual and Data-based Investigation of Genetic Influences and Brain Asymmetry: A Twin Study of Multiple Structural Phenotypes

2014 ◽  
Vol 26 (5) ◽  
pp. 1100-1117 ◽  
Author(s):  
Lisa T. Eyler ◽  
Eero Vuoksimaa ◽  
Matthew S. Panizzon ◽  
Christine Fennema-Notestine ◽  
Michael C. Neale ◽  
...  
Keyword(s):  
Twin Study ◽  
Genetic Factors ◽  
Right Hemisphere ◽  
Genetic Correlations ◽  
Monozygotic Twin ◽  
Genetic Influences ◽  
Size Difference ◽  
Subcortical Structures ◽  
Structural Asymmetry ◽  
Left And Right

Right–left regional cerebral differences are a feature of the human brain linked to functional abilities, aging, and neurodevelopmental and mental disorders. The role of genetic factors in structural asymmetry has been incompletely studied. We analyzed data from 515 individuals (130 monozygotic twin pairs, 97 dizygotic pairs, and 61 unpaired twins) from the Vietnam Era Twin Study of Aging to answer three questions about genetic determinants of brain structural asymmetry: First, does the magnitude of heritability differ for homologous regions in each hemisphere? Despite adequate power to detect regional differences, heritability estimates were not significantly larger in one hemisphere versus the other, except left > right inferior lateral ventricle heritability. Second, do different genetic factors influence left and right hemisphere size in homologous regions? Interhemispheric genetic correlations were high and significant; in only two subcortical regions (pallidum and accumbens) did the estimate statistically differ from 1.0. Thus, there was little evidence for different genetic influences on left and right hemisphere regions. Third, to what extent do genetic factors influence variability in left–right size differences? There was no evidence that variation in asymmetry (i.e., the size difference) of left and right homologous regions was genetically determined, except in pallidum and accumbens. Our findings suggest that genetic factors do not play a significant role in determining individual variation in the degree of regional cortical size asymmetries measured with MRI, although they may do so for volume of some subcortical structures. Despite varying interpretations of existing data, we view the present results as consistent with previous findings.

scholarly journals A Reevaluation of the 1990 “Minnesota Study of Twins Reared Apart” IQ Study

2022 ◽  
Author(s):  
Jay Joseph
Keyword(s):  
Cognitive Ability ◽  
Genetic Factors ◽  
Model Fitting ◽  
Monozygotic Twin ◽  
Cohort Effects ◽  
Genetic Influences ◽  
Control Group ◽  
Dizygotic Twin ◽  
Full Sample ◽  
Iq Scores

In 1990, Thomas J. Bouchard, Jr. and colleagues published the widely cited 1990 “Minnesota Study of Twins Reared Apart” (MISTRA) Science IQ study. To arrive at the conclusion that “IQ is strongly affected by genetic factors,” Bouchard and colleagues omitted their control group reared-apart dizygotic twin (“DZA”) IQ-score correlations. Near-full-sample correlations published after the study’s 2000 endpoint show that the reared-apart monozygotic twin (“MZA”) and DZA group IQ correlations did not differ at a statistically significant level, suggesting that the study failed the first step in determining that IQ scores are influenced by heredity. After bypassing the model-fitting technique they used in most non-IQ MISTRA studies, the researchers assumed that the MZA group IQ-score correlation alone “directly estimates heritability.” This method was based on unsupported assumptions by the researchers, and they largely overlooked the confounding influence of cohort effects. Bouchard and colleagues then decided to count most environmental influences they did recognize as genetic influences. I conclude that the MISTRA IQ study failed to discover genetic influences on IQ scores and cognitive ability across the studied population, and that the study should be evaluated in the context of psychology’s replication problem.

Muscle Dissatisfaction and Muscle-Enhancing Substance Use: A Population-Based Twin Study in Young Adult Men

2006 ◽  
Vol 9 (3) ◽  
pp. 431-437 ◽  
Author(s):  
Anu Raevuori ◽  
Anna Keski-Rahkonen ◽  
Richard J. Rose ◽  
Aila Rissanen ◽  
Jaakko Kaprio
Keyword(s):  
Substance Use ◽  
Environmental Factors ◽  
Twin Study ◽  
Genetic Factors ◽  
Population Based ◽  
Tetrachoric Correlation ◽  
Polychoric Correlation ◽  
Adult Men ◽  
Genetic And Environmental Factors ◽  
Best Fit

AbstractIn the population-based FinnTwin16 study, proportions of genetic and environmental factors contributing to muscle dissatisfaction and muscle-enhancing substance use were assessed in 319 pairs of twin brothers: 141 monozygotic (MZ) and 178 dizygotic (DZ) pairs. In addition there were 86 twin individuals from pairs in which only one co-twin responded. Of all respondents, 30% experienced high muscle dissatisfaction. The corresponding proportion of muscle-enhancing substance use was 10%. The subjects were similar in age (23.8 years, 95% confidence interval [CI] 23.76–23.84), body mass index (23.7, 95% CI 23.5–23.9), and waist circumference (84.5 cm, 95% CI 83.7–85.2), independent of their muscle dissatisfaction or muscle-enhancing substance use status and independent of their zygosity. The MZ polychoric correlation for muscle dissatisfaction was .39 (95% CI .17–.58) and .27 for DZ pairs (95% CI .07–.46). The MZ tetrachoric correlation for muscle-enhancing substance use was .65 (95% CI .28–.87) and .56 for DZ pairs (95% CI .26–.78). The AE model, where additive genetic factors (A) accounted for 42% (95% CI .23–.59) and unique environmental factors (E) 58% (95% CI .41–.77) of the liability, provided the best fit for muscle dissatisfaction. The CE model, where common environmental factors (C) accounted for 60% (95% CI .37–.77) and unique environmental factors (E) 40% (95% CI .23–.63) of the liability, provided the best fit for muscle-enhancing substance use. Both genetic and unique (nonfamilial) environmental factors are involved in muscle dissatisfaction in the population. Nongenetic factors (both familial and non-familial) appear to best explain the use of muscle-enhancing substances.

Absolute Pitch Twin Study and Segregation Analysis

2011 ◽  
Vol 14 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Elizabeth Theusch ◽  
Jane Gitschier
Keyword(s):  
Twin Study ◽  
Segregation Analysis ◽  
Genetic Factors ◽  
Large Population ◽  
Absolute Pitch ◽  
Monozygotic Twin ◽  
Segregation Ratio ◽  
Unknown Etiology ◽  
Dizygotic Twin ◽  
Using Data

Absolute pitch is a rare pitch-naming ability with unknown etiology. Some scientists maintain that its manifestation depends solely on environmental factors, while others suggest that genetic factors contribute to it. We sought to further investigate the hypothesis that genetic factors support the acquisition of absolute pitch and to better elucidate the inheritance pattern of this trait. To this end, we conducted a twin study and a segregation analysis using data collected from a large population of absolute pitch possessors. The casewise concordance rate of 14 monozygotic twin pairs, 78.6%, was significantly different from that of 31 dizygotic twin pairs, 45.2%, assuming single ascertainment (x2 = 5.57, 1 df, p = .018), supporting a role for genetics in the development of absolute pitch. Segregation analysis of 1463 families, assuming single ascertainment, produced a segregation ratio pD = .089 with SEpD = 0.006. Unlike an earlier segregation analysis on a small number of absolute pitch probands from musically educated families, our study indicates that absolute pitch is not inherited in a simple Mendelian fashion. Based on these data, absolute pitch is likely genetically heterogeneous, with environmental, epigenetic, and stochastic factors also perhaps contributing to its genesis. These findings are in agreement with the results of our recent linkage analysis.

scholarly journals The genetic etiology of longitudinal measures of predicted brain ageing in a population-based sample of mid to late-age males

2021 ◽  
Author(s):  
Nathan A Gillespie ◽  
Sean N Hatton ◽  
Donald H Hagler ◽  
Anders M Dale ◽  
Jeremy A Elman ◽  
...  
Keyword(s):  
Twin Study ◽  
Population Based ◽  
Genetic Influences ◽  
Genetic Etiology ◽  
Genetic Heritability ◽  
Brain Ageing ◽  
Vietnam Era ◽  
Highly Correlated ◽  
Changes Over Time ◽  
Over Time

Despite their increasing application, the genetic and environmental etiology of global predicted brain ageing (PBA) indices is unknown. Likewise, the degree to which genetic influences in PBA are longitudinally stable and how PBA changes over time are also unknown. We analyzed data from 734 men from the Vietnam Era Twin Study of Aging with repeated MRI assessments between the ages 52 to 72 years. Biometrical genetic analyses revealed significant and highly correlated estimates of additive genetic heritability ranging from 59% to 75%. Multivariate longitudinal modelling revealed that covariation between PBA at different timepoints could be explained by a single latent factor with 73% heritability. Our results suggest that genetic influences on PBA are detectable in midlife or earlier, are longitudinally very stable, and are largely explained by common genetic influences.

scholarly journals Genetic Factors Explain Variation in the Age at Onset of Psoriasis: A Population-based Twin Study

2016 ◽  
Vol 96 (1) ◽  
pp. 35-38 ◽  
Author(s):  
A Lønnberg ◽  
L Skov ◽  
D Duffy ◽  
A Skytthe ◽  
K Kyvik ◽  
...  
Keyword(s):  
Twin Study ◽  
Genetic Factors ◽  
Age At Onset ◽  
Population Based

scholarly journals Genetic and environmental influences on obsessive–compulsive behaviour across development: a longitudinal twin study

2014 ◽  
Vol 45 (7) ◽  
pp. 1539-1549 ◽  
Author(s):  
G. Krebs ◽  
M. A. Waszczuk ◽  
H. M. S. Zavos ◽  
D. Bolton ◽  
T. C. Eley
Keyword(s):  
Genetic Factors ◽  
Population Based ◽  
Genetic Influence ◽  
Genetic Influences ◽  
Shared Environment ◽  
Obsessive Compulsive ◽  
New Genes ◽  
Compulsive Behaviour ◽  
The Stability ◽  
Over Time

BackgroundLittle is known about the factors influencing the stability of obsessive–compulsive behaviour (OCB) from childhood to adolescence. The current study aimed to investigate: (1) the stability of paediatric OCB over a 12-year period; (2) the extent to which genetic and environmental factors influence stability; and (3) the extent to which these influences are stable or dynamic across development.MethodThe sample included 14 743 twins from a population-based study. Parental ratings of severity of OCB were collected at ages 4, 7, 9 and 16 years.ResultsOCB was found to be moderately stable over time. The genetic influence on OCB at each age was moderate, with significant effects also of non-shared environment. Genetic factors exerted a substantial influence on OCB persistence, explaining 59–80% of the stability over time. The results indicated genetic continuity, whereby genetic influences at each age continue to affect the expression of OCB at subsequent ages. However, we also found evidence for genetic attenuation in that genetic influences at one age decline in their influence over time, and genetic innovation whereby new genes ‘come on line’ at each age. Non-shared environment influenced stability of OCB to a lesser extent and effects were largely unique to each age and displayed negligible influences on OCB at later time points.ConclusionsOCB appears to be moderately stable across development, and stability is largely driven by genetic factors. However, the genetic effects are not entirely constant, but rather the genetic influence on OCB appears to be a developmentally dynamic process.

Genetic Factors in Seizures: A Population-Based Study of 47,626 US, Norwegian and Danish Twin Pairs

2005 ◽  
Vol 8 (2) ◽  
pp. 138-147 ◽  
Author(s):  
Marianne J. Kjeldsen ◽  
Linda A. Corey ◽  
Marit H. Solaas ◽  
Mogens L. Friis ◽  
Jennifer R. Harris ◽  
...  
Keyword(s):  
Genetic Factors ◽  
Febrile Seizures ◽  
The United States ◽  
Population Based ◽  
Relative Importance ◽  
Population Based Study ◽  
History Of ◽  
Unselected Population ◽  
Genetic And Environmental Factors ◽  
Danish Twin

AbstractThe purpose of the study was to describe a large sample of twins reporting a history of seizures, to characterize seizures in the three subpopulations, and to estimate the relative importance of genetic and environmental factors in seizure occurrence. Seizure history was determined by questionnaires completed by twins in population-based twin registries in the United States, Norway and Denmark. Concordance rates were calculated for all seizure categories within and across twin populations. Of 47,626 twin pairs evaluated, 6234 reported a history of seizures in one or both twins. Concordance rates were significantly higher for monozygotic (MZ) versus dizygotic (DZ) pairs for all seizure categories within and across populations. The results of this study involving the largest unselected, population-based sample of twins with seizures assembled to date confirm the importance of genetic factors in determining risk for epilepsy, febrile seizures, other seizures and staring spells. This sample is likely to provide an important resource for studying the genetics of epilepsy subtypes and febrile seizures.

The genetic etiology of childhood depressive symptoms: A developmental perspective

1996 ◽  
Vol 8 (4) ◽  
pp. 751-760 ◽  
Author(s):  
Anita Thapar ◽  
Peter McGuffin
Keyword(s):  
Depressive Symptoms ◽  
Genetic Factors ◽  
Self Esteem ◽  
Population Based ◽  
Genetic Influences ◽  
Genetic Etiology ◽  
Population Based Study ◽  
Age Related ◽  
Developmental Variations ◽  
Age Related Changes

AbstractAlthough there is some evidence to suggest that depressive symptoms show age-related changes, it remains uncertain as to whether there are also developmental variations in the etiology of depression. In this article, we present findings from a population-based study of twins aged 8 to 16 years with the aim of examining the genetic etiology of depressive symptoms and the effects of age. The results suggest that environmental factors influence the transmission of depressive symptoms in childhood. However depressive symptoms in adolescence appear to be highly heritable. The etiology of depressive symptoms was further explored using factor-derived scores that again suggested the importance of genetic factors in adolescence. However there was some suggestion that genetic influences may contribute to certain types of symptoms (self-deprecation/self-esteem) even in childhood.

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