scholarly journals The Brazilian Twin Registry

2016 ◽  
Vol 19 (6) ◽  
pp. 687-691 ◽  
Author(s):  
Paulo H. Ferreira ◽  
Vinicius C. Oliveira ◽  
Daniela R. Junqueira ◽  
Lígia C. Cisneros ◽  
Lucas C. Ferreira ◽  
...  

The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.

2012 ◽  
Vol 16 (1) ◽  
pp. 34-42 ◽  
Author(s):  
John L. Hopper ◽  
Debra L. Foley ◽  
Paul A. White ◽  
Vincent Pollaers

The Australian Twin Registry (ATR) is a national volunteer resource of twin pairs and higher-order multiples willing to consider participating in health, medical, and scientific research. The vision of the ATR is ‘to realize the full potential of research involving twins to improve the health and well-being of all Australians’. The ATR has been funded continuously by the National Health and Medical Council for more than 30 years. Its core functions entail the recruitment and retention of twin members, the maintenance of an up-to-date database containing members’ contact details and baseline information, and the promotion and provision of open access to researchers from all institutes in Australia, and their collaborators, in a fair and equitable manner. The ATR is administered by The University of Melbourne, which acts as custodian. Since the late 1970s the ATR has enrolled more than 40,000 twin pairs of all zygosities and facilitated more than 500 studies that have produced at least 700 peer-reviewed publications from classical twin studies, co-twin control studies, within-pair comparisons, twin family studies, longitudinal twin studies, randomized controlled trials, and epigenetics studies, as well as studies of issues specific to twins. New initiatives include: a Health and Life Style Questionnaire; data collection, management, and archiving using a secure online software program (The Ark); and the International Network of Twin Registries. The ATR's expertise and 30 years of experience in providing services to national and international twin studies has made it an important resource for research across a broad range of disciplines.


2009 ◽  
Vol 12 (2) ◽  
pp. 127-131 ◽  
Author(s):  
Jaqueline M. Vink ◽  
Annemieke S. Staphorsius ◽  
Dorret I. Boomsma

AbstractCaffeine is by far the most commonly used psychoactive substance. Caffeine is consumed regularly as an ingredient of coffee. Coffee consumption and coffee preference was explored in a sample of 4,495 twins (including 1,231 pairs) registered with the Netherlands Twin Registry. Twin resemblance was assessed by tetrachoric correlations and the influence of both genetic and environmental factors was explored with model fitting analysis in MX. Results showed moderate genetic influences (39%) on coffee consumption. The remaining variance was explained by shared environmental factors (21%) and unique environmental factors (40%). The variance in coffee preference (defined as the proportion of coffee consumption relative to the consumption of coffee and tea in total) was explained by genetic factors (62%) and unique environmental factors (38%).


2012 ◽  
Vol 16 (1) ◽  
pp. 455-462 ◽  
Author(s):  
Eric Strachan ◽  
Corinne Hunt ◽  
Niloofar Afari ◽  
Glen Duncan ◽  
Carolyn Noonan ◽  
...  

The University of Washington Twin Registry is a unique community-based registry of twin pairs who join specifically to participate in scientific research. It was founded in 2002 to serve as a resource for investigators throughout the scientific community. Current enrollment exceeds 7,200 pairs, and plans are in place to increase enrollment to 10,000 pairs by 2015. In addition to serving as a recruitment base for new research studies, the registry maintains extensive and continually expanding survey data on physical and mental health, as well as a biorepository that includes DNA from more than 8,800 individual twins. The registry is engaged in linking member data to birth records and to diagnostic and procedure variables for hospital-based care provided to members in Washington State. It also incorporates several innovative variables relevant to the built and social environments, which were created by geocoding twin addresses and linking the resulting coordinates to geospatial information systems databases. This combination of existing data and biospecimens, characterizing a group of twins who are willing to participate in research, is a valuable resource for the new wave of twin studies. These include ‘omics’, epigenetics, gene-by-environment interactions, and other novel methods to understand human health.


2017 ◽  
Vol 36 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Peter Beattie

Twin studies have revealed political ideology to be partially heritable. Neurological research has shown that ideological differences are reflected in brain structure and response, suggesting a direct genotype-phenotype link. Social and informational environments, however, also demonstrably affect brain structure and response. This leads to a “chicken-and-egg” question: do genes produce brains with ideological predispositions, causing the preferential absorption of consonant information and thereby forming an ideology, or do social and informational environments do most of the heavy lifting, with genetic evidence the spurious artifact of outdated methodology? Or are both inextricably intertwined contributors? This article investigates the relative contributions of genetic and environmental factors to ideological development using a role-play experiment investigating the development of opinions on a novel political issue. The results support the view that the process is bidirectional, suggesting that, like most traits, political ideology is produced by the complex interplay of genetic and (social/informational) environmental influences.


2011 ◽  
Vol 14 (6) ◽  
pp. 539-543 ◽  
Author(s):  
Holly M. Baughman ◽  
Sara Schwartz ◽  
Julie Aitken Schermer ◽  
Livia Veselka ◽  
K. V. Petrides ◽  
...  

The present study is the first to examine relationships between alexithymia and trait emotional intelligence (trait EI or trait emotional self-efficacy) at the phenotypic, genetic, and environmental levels. The study was also conducted to resolve inconsistencies in previous twin studies that have provided estimates of the extent to which genetic and environmental factors contribute to individual differences in alexithymia. Participants were 216 monozygotic and 45 dizygotic same-sex twin pairs who completed the Toronto Alexithymia Scale-20. In a pilot study, a sub-sample of 118 MZ and 27 DZ pairs also completed the Trait Emotional Intelligence Questionnaire. Results demonstrated that a combination of genetic and non-shared environmental influences contribute to individual differences in alexithymia. As expected, alexithymia and trait EI were negatively correlated at the phenotypic level. Bivariate behavioral genetic analyses showed that that all but one of these correlations was primarily attributable to correlated genetic factors and secondarily to correlated non-shared environmental factors.


2019 ◽  
Vol 30 (9-10) ◽  
pp. 237-244
Author(s):  
Jacob E. Moskowitz ◽  
Federica Andreatta ◽  
James Amos-Landgraf

Abstract Tumor multiplicity in the ApcMin (Min) mouse model of CRC is a classic quantitative trait that is subject to complex genetic and environmental factors, and therefore serves as an ideal platform to study modifiers of disease. While disparate inbred genetic backgrounds have well-characterized modifying effects on tumor multiplicity, it is unclear whether more closely related backgrounds such as C57BL/6J and C57BL6/N differentially modify the phenotype. Furthermore, it is unknown whether the complex gut microbiota (GM) influences the effects of these background strains. We assessed tumor multiplicity in F1 mice generated from the original Min colony from the McArdle Laboratory at the University of Wisconsin (C57BL/6JMlcr-ApcMin) crossed with either C57BL/6J or C57BL/6N wild-type mice. We also used complex microbiota targeted rederivation to rederive B6NB6JMF1-ApcMin embryos using surrogate dams harboring complex GMs from two different sources to determine the effects of complex GM. Both B6/J and B6/N backgrounds significantly repressed tumor multiplicity. However, the B6/N background conferred a stronger dominant suppressive effect than B6/J. Moreover, we observed that complex GM likely modulated B6/N-mediated adenoma repression such that two distinct communities conferred differential tumor multiplicity in isogenic B6NB6JMF1-ApcMin mice. Although we cannot rule out possible maternal effects of embryo transfer, we show that B6/J and B6/N have modifier effects on Min, and these effects are further altered by the complex GM. Foremost, strict attention to genetic background and environmental variables influencing the GM is critical to enhance reproducibility in models of complex disease traits.


2019 ◽  
Vol 22 (2) ◽  
pp. 95-98 ◽  
Author(s):  
Ally R. Avery ◽  
Glen E. Duncan

AbstractApproximately 12% of U.S. adults have type 2 diabetes (T2D). Diagnosed T2D is caused by a combination of genetic and environmental factors including age and lifestyle. In adults 45 years and older, the Discordant Twin (DISCOTWIN) consortium of twin registries from Europe and Australia showed a moderate-to-high contribution of genetic factors of T2D with a pooled heritability of 72%. The purpose of this study was to investigate the contributions of genetic and environmental factors of T2D in twins 45 years and older in a U.S. twin cohort (Washington State Twin Registry, WSTR) and compare the estimates to the DISCOTWIN consortium. We also compared these estimates with twins under the age of 45. Data were obtained from 2692 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs over 45 and 4217 twin pairs under 45 who responded to the question ‘Has a doctor ever diagnosed you with (type 2) diabetes?’ Twin similarity was analyzed using both tetrachoric correlations and structural equation modeling. Overall, 9.4% of MZ and 14.7% of DZ twins over the age of 45 were discordant for T2D in the WSTR, compared to 5.1% of MZ and 8% of DZ twins in the DISCOTWIN consortium. Unlike the DISCOTWIN consortium in which heritability was 72%, heritability was only 52% in the WSTR. In twins under the age of 45, heritability did not contribute to the variance in T2D. In a U.S. sample of adult twins, environmental factors appear to be increasingly important in the development of T2D.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  

Abstract Twin design is an important tool to analyze the role of genetic and environmental factors, and to better understand causal mechanisms in public health research. Twin studies have reliably shown that genetic factors are important not only for physiological traits but also for psychological and health behavioral traits as well as for health-related work incapacity in terms of sick leave and disability pension. As many countries face an aging workforce, it is becoming ever more important to understand the underlying causes of work incapacity across the entire working life. In the past decade, twin data in combination with national register data have been used to deepen our understanding of the role of genetic and environmental influences on the complex processes of sick leave and disability pension. The aim of this workshop is to present and discuss methods and results of studies based on the large Swedish, Finnish and Norwegian twin cohorts. Linear structural equations are intensively utilized in modern methods of twin studies. A variety of models are available to answer different research questions, such as the dynamics behind associations between traits and developmental processes in longitudinal designs - models also applicable in health at work and social security. Further, analyzing twin pairs discordant for an outcome or risk factor (co-twin control) provides a unique possibility to control for familial (genetic and shared environmental) factors, since cases and controls are matched optimally being twins. Findings based on twin cohorts suggest that familial factors are relevant to many risk factors as well as for work incapacity. By controlling for these unobserved confounding factors, the co-twin control design may provide more accurate estimates of risk factors for work incapacity and complement the epidemiological findings of unrelated subjects. Based on population-based twin cohort studies with long follow-up, indications also exist that familial confounding may have different roles in the associations between risk factors and work incapacity. For example, in regard to various disability pension diagnosis groups and depending on study designs (one vs. two time points, longer vs. shorter follow-up etc.). Results from prospective studies on various risk factors, including adolescents’ mental health problems, for future sick leave and disability pension will be presented. Another presentation focuses on the stability and change in genetic and environmental factors influencing work incapacity from age 18 until retirement and the likelihood of causality between educational attainment, lifestyle and work incapacity. Finally, results on adverse outcomes of sick leave due to mental disorders using an open cohort design adjusting for familial factors will be presented. During the time of rapid development in molecular genetics, the twin study design has maintained its importance and will continue to cast light on different aspects of work incapacity. Key messages Twin design offers a unique tool in public health research to examine and control for familial (genetic and shared environmental) factors. Genetic factors seem to play an important role in understanding the complex causes of work incapacity in terms of sick leave and disability pension.


1999 ◽  
Vol 11 (2) ◽  
pp. 45-47
Author(s):  
P. McGuffin

Most forms of behaviour whether normal or abnormal, show a tendency to run in families. However, these can range from symptoms of dementia and movement disorder caused by the comparatively rare autosomal dominant Huntington's disease to common everyday aspects of behaviour such as religious persuasion or career choice. Normal behaviours and most common disorders do not show simple mendelian inheritance but instead have more complex patterns of transmission involving either major genes with incomplete penetrance, multiple genes of small effect, or a combination of the two. In addition, common complex phenotypes usually involve the combination of genetic and environmental factors. Therefore once family studies have shown that a disorder or trait is familial the next stage is to perform twin studies and, if possible adoption studies to investigate whether this results from shared genes, shared environment or a combination of the two.


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