diseases in twins

..The resource has led to many successful and innovative research projects particularly in common age-related diseases, and has led to collaborations with over 80 groups worldwide...

..quot; The Twin Spine Study, a research program on the etiology and pathogenesis of disc degeneration, has contributed to a substantial revision of this view of determinants of lumbar disc degeneration...

..It is not known whether genetic effects on major depression are constant across historical cohorts...

..Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes...

..The identification of specific nonshared environments responsible for the variance in behaviour problems is a key challenge...

..The relationship between personality and psychiatric illness is complex. It is not clear whether one directly causes the other...

..To assess the relative risk for amyotrophic lateral sclerosis (ALS) in families of ALS patients...

..We offer suggestions for future research to address these issues, and we emphasize the need for additional research to examine possible shared environmental factors related to ADHD...

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..In particular, we describe recent efforts to screen all twins born between 1959 and 1985, and young twin pairs when they turn 9 and 12 years of age. For these studies, we present initial frequencies of common conditions and exposures...

..Attention-deficit/hyperactivity disorder (ADHD) is a heterogeneous neurodevelopmental disorder that in some cases is accompanied by antisocial behavior...

..Prior studies suggest that the personality traits of neuroticism and extroversion may be related to the liability to major depression (MD)...

..Because women have higher levels of neuroticism and twice the risk of lifetime generalized anxiety disorder of men, gender-specific effects were also explored...

..These results are consistent with other studies in suggesting that genetic factors play a significant role in the causes of individual differences in relative body weight and human adiposity...

..To identify whether a shared genetic influence accounts for the occurrence of OA at different skeletal sites...

..To investigate health-related and sociodemographic risk factors for disability pensions (DP) due to low back disorders (LBD)...

..Our results also provide prospective evidence that early excess BMI may have serious long-term health consequences, and that this risk is not limited to minorities or adults of lower socioeconomic status...

..The Danish Twin Registry was established formally in 1954 and thus celebrates its 50th anniversary in 2004. Here we give an account of its founding and the early years, and a brief summary of more recent progress...

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..These estimates indicate to what extent genetic factors contribute to the etiology of this disease...

..For all assays, results did not differ between the group of twins with CFS and the healthy twins...

..Among monozygotic twins where both twins had Alzheimer's disease, the within pair difference in age of onset ranged from both becoming demented in the same year to 7 years difference in onset...

..To evaluate whether differences in the intrauterine environment caused discordant Duane's retraction syndrome in monozygotic twins...

..5%) and females (median, 30.5%). For both sexes, weight changes were not heritable. Sex-by-genotype analyses suggested that the genetic factors influencing female seasonality may not be the same as those influencing male seasonality...

..The effect of genes that influence environmental exposure might be mediated through personality and we therefore also examined the association between life events and personality (neuroticism and extraversion)...

..0023), and milder disease was associated with late as compared with early truncating mutations ( P = 0.0190)...

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..CONCLUSION: A high concordance rate of strabismic phenotypes, predominantly of accommodative esotropia and intermittent exotropia in monozygosity, suggests the genetic background for these types of strabismus...

..While, these findings may reflect methodological limitations, it is also argued that they arise as a consequence of the substantially different biology of fetal growth in twins...

..Discordance of infantile esotropia and pursuit asymmetry in monozygous twins implicates environmental in addition to genetic causes...

..Such alterations in dopaminergic and noradrenergic function are apparently necessary for the clinical efficacy of pharmacologic treatments of ADHD...

..An age-related heterogeneity was observed, with higher progression to diabetes for twins of patients diagnosed at a younger age...

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..Anorexia nervosa (AN) is a serious mental illness with marked morbidity and mortality...

..Previous research has shown an association between bulimia (BN) and drug use disorders (DUD). The purpose of the present study was to investigate possible influences on the comorbidity between BN and DUD...

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..After incorporating twins and multiples from various other feasibility studies we now have 19,040 multiples with 8.46 twins per 1000 people in the Colombo district...

..Given their versatility, population-based family studies could become a principal framework in epidemiology, and move genetics from its traditional focus on high-risk families to give it a wider clinical and population health relevance...

..In contrast, somatization was shown to be moderately heritable. CONCLUSION: Genetic factors are of little or no influence on IBS where the predominant influences appear to be environmental...

..These studies typically used DSM ADHD symptoms collected by telephone or interviews with mothers. The purpose of this study was to test the genetic architecture of ADHD by using the ADHD index from Conners' Rating Scales-Revised...

..Twin studies of obsessive-compulsive disorder have indicated a significant genetic component to its expression...

..6 per 1000 livebirths respectively. A prospective Multiple Pregnancy Register not only allows monitoring of trends in multiple birth rates and mortality, but also etiological research and long-term follow-up studies...

..This suggests that the regulation of the Pf155/RESA antibody responses seen in this study reflects the impact of factors encoded by genes outside the HLA class II regions...

..This study aimed to examine the characteristic features of depression in Sri Lanka, and to identify environmental risk factors...

..In the following, we will summarize the content of the database, describe for the first time recent data collection efforts and review some of the principal findings that have come from the Registry...

..Gender differences in the symptoms of major depression have received limited research attention. The aim of this study was to explore these differences in male-female twin pairs...

..Twin data permit decomposition of comorbidity into genetically and environmentally derived correlations. No previous twin study includes all major forms of anxiety disorder...

..We conclude that there is no difference in diagnosis-to-delivery interval or survival for any treatment for TTTS compared to expectant management. The lack of significance appears to be due to small sample sizes...

..Lower birth weight is a causal risk factor for child problem behavior, the effects of which may well extend into adulthood...

..Although twin studies are powerful tools, their methodology can be arcane and their implications easily misinterpreted...

..To study the influence of zygosity on the metabolic variables involved in the pathophysiology of type 2 diabetes...

..Identifying genes involved in the excess consumption of dietary fat will be an important key to our understanding of the genetic disposition toward common dietary obesity...

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..This paper presents the rationale for the study, describes its context, and the methods for twin ascertainment and data collection...

..These results suggest that these problems are not cross-transmitted within families and suggest that the addiction model of eating disorders may be simplistic...

..Method A cohort of 11 162 same-sexed Swedish twins born between 1906 and 1958 was used in order to investigate the risk of developing Type 2 diabetes between and within twin pairs by utilizing random effects linear models...

..Although these genetic estimates for incident disease are lower than those for prevalent disease, the importance of genetic factors for liability to Alzheimer's disease is considerable even late in life...

..In this study, our purpose was to detect all cases of dementia in an established twin registry and to estimate total extent of genetic contribution to liability to Alzheimer's disease...

..With these bodies of literature as a starting point, we evaluate critically the current state of research on molecular genetic studies of anorexia nervosa and provide guidance for future research...

..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...

..The purpose of this study was to investigate whether the three disorders in the bipolar spectrum, Bipolar I disorder, Bipolar II disorder and Cyclothymia, are various expressions of an underlying genetic commonality...

..The present account provides a comprehensive and up-to-date review of the twin studies on this topic...

..However, little is known about gene-environment interplay in early cortisol reactivity...

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..The development of the CTR is an ongoing and evolving process, and it has proved to be a valuable resource, relatively representative of the population from which it was drawn...

..We examined genetic and environmental influences on childhood AS, HBP, panic/somatic ratings, and their associations...

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..Instead, friends' social aggression was directly related to children's social aggression, in addition to genetic effects on this behavior. Theoretical and practical implications of these results are discussed...

..The current state and future plans for the Chinese National Twin Registry will be discussed in this article...

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..We interpret these preliminary findings tentatively in the context of gene-environment interaction on anxiety in general, and on early separation and later panic anxiety in particular...

..The results suggest that correlated risk factors are a better explanation for the comorbidity between ADHD and CD than a third, independent ADHD+CD subtype...

..Relatively little is known about the genetic architecture of childhood behavioral disorders in very young children...

..Although an obvious environmental factor influencing drug use, the sources of individual differences in drug availability (DA) are unknown...

..The aim of the present study is to evaluate whether genes influencing the rate of dizygotic twinning and genes of importance for developing schizophrenia can be associated...

..A better understanding of the mechanisms of familial transmission for these "externalizing" disorders is necessary to better understand their etiology and to help develop intervention strategies...

..Information on the heritability of the development of alcohol dependence could provide a better understanding of the importance of genetic components in disease transition...

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..Results support a differentiated view of SWB-health relations, and imply that both genes and environment play important roles in the associations between well-being and health...

..We conducted a sibling/twin/adoption study of substance initiation, use, and problem use, estimating the relative contribution of genetic and environmental influences on these phenotypes in adolescents...

..Data on use and misuse of six classes of illicit substances by male twin pairs were used to examine whether genetic and shared environmental risk factors for substance use disorders are substance-specific or -nonspecific in their effect...

..To examine the genetic and environmental influences on the known association between body mass index (BMI) and knee osteoarthritis (OA), using adult twin data...

..Similarly little is known about the influence of genetic factors on the clinical course of this disease. The present study addresses these issues...

..The recent identification of the IBD1 gene (NOD2) with mutations that are associated with susceptibility to Crohn's disease will have a major impact on the understanding of the genetics of this disease...

..The familial aggregation of GAD in this sample was only modest. In the best-fitting models, the heritability of GAD was the same in men and women, estimated at about 15% to 20%, with no effects of gender-specific genes detected...

..To estimate the heritability of frozen shoulder (FS) and tennis elbow (TE) and to examine the two disorders for possible genetic or environmental associations...

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..These results suggest that these disorders each have etiologically distinct components and also have significant genetic and unique environmental contributions in common...

..Although several genetic determinants (mutations or polymorphisms) have been associated with increased risk of venous thromboembolism, the overall influence of genetic factors on this disease is unknown...

..In this study, we explored the association of birth weight with osteoporosis (OP) and osteoarthritis (OA), in a large national cohort of female twins...

..There has been little use of genetic model fitting and no analyses to explore the etiological overlap with unipolar depression (UPD)...

..The authors report what appears to be the first twin study of bipolar I disorder involving a population-based twin sample, in which the diagnoses were made by using structured, personal interviews...

..Previous research has reported both a moderate degree of comorbidity between cannabis dependence and major depressive disorder (MDD) and that early-onset cannabis use is associated with increased risks for MDD...

..The disability and hardship associated with affective disorder is shared by the family members of affective patients and might affect the family member's quality of life...

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..To explore the genetic and environmental influences on DSM-IV conduct disorder (CD) aggressive and nonaggressive subscales, taking into account age and sex differences...

..These analyses indicate that the NDSS functions well in a Finnish family-based sample and provide additional validation of a new scale developed to capture complex behavioural features of nicotine dependence...

..This study was intended to examine whether autoimmune thyroiditis is related to the disease itself, to the (genetic) vulnerability to develop bipolar disorder, or both...

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..5 to 1.0 centiMorgans and a cooperative, stable population make Ireland ideal for linkage disequilibrium studies of schizophrenia. ..

..Phenotypic analyses of the data will focus on detecting familial resemblance for symptoms, factors and typologies of AD to be used to define putative etiologic subtypes of AD for future linkage analyses. ..

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..In this competitive renewal, we request 5 further years of support with the primary goals of identifying these pathogenic variant(s) and relating them to the biology of the gene, gene product and disease. ..

..This study has the capacity to address several key and largely unanswered empirical questions about PDs, the answers to which will be critical for proposed revisions in DSM-V. ..

..To conduct this project we have assembled a team of experts in clinical assessment, statistical genetics and molecular genetics...

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..We will develop multivariate genetic models including specified environmental risk factors that will provide realistic etiologic models for these disorders that incorporate all major risk factor domains. ..

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..We will develop multivariate genetic models including specified environmental risk factors that will provide realistic etiologic models for these disorders that incorporate all major risk factor domains...

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..Such findings should ultimately inform individually-tailored interventions aimed at the amelioration of child CP. ..

..Such findings should ultimately provide information for more effective individually-tailored interventions aimed at the amelioration of child CP. ..

..Such findings should ultimately provide information for more effective individually-tailored interventions aimed at the amelioration of child CP. ..

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..The primary method of analysis will be twin structural equation modeling. ..

..Greater insight into neurobiological mechanisms will narrow the search for candidate genes and contribute to improved treatment and prevention of these disorders. ..

..Greater insight into neurobiological factors that contribute to these genetic effects will narrow the search for candidate genes and ultimately contribute to improved treatment and prevention of these disorders. ..

..Greater insight into neurobiological mechanisms will narrow the search for candidate genes and contribute to improved treatment and prevention of these disorders. ..

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..Greater insight into neurobiological mechanisms will narrow the search for candidate genes and contribute to improved treatment and prevention of these disorders. ..

..Findings from this study will significantly increase understanding of developmental risk factors for eating disorders and potentially inform intervention and prevention efforts aimed at their amelioration. ..

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..Efforts toward the prevention, early identification and treatment of PTSD and the identification of factors that mediate its adverse effects could reduce morbidity and mortality from CVD. ..

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..The applicant is the Center's Co-Pi and Scientific Director as well as PI of the CGS project. ..

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