The Australian Twin Registry, established in the late 1970s, is a volunteer registry of over 30,000 pairs of Australian twins of all zygosity types and ages unselected for their health or medical history. The ATR does not undertake research itself but acts as facilitator, providing an important national and international resource for medical and scientific researchers across a broad range of disciplins. Pubmed abstract
Brasilian Twin Registry - BTR
The Brazilian Twin Registry 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. Pubmed abstract
Cardiff Twin Registry - CASTANET
The Cardiff Twin Registry was initially established in Cardiff in 1992 and was extended to include twins across Wales in 1997 and Greater Manchester in 1996. The combined register is now held in the Section of Child & Adolescent Psychiatry, Department of Psychological Medicine and includes approximately 6,000 twin pairs who were born in Wales and the Greater Manchester area. Pubmed abstract
Colorado Twin Registry - CTR
The Colorado Twin Registry is a population based registry housed at the Institute for Behavioral Genetics (IBG), University of Colorado. Recruitment has been ongoing since 1968. Four samples construct the CTR: the Community Twin Sample (CTS), Infant Twin Sample (ITS), Longitudinal Twin Sample (LTS), and the Early Reading Development Sample (ERDS). Criteria for enrollment, recruitment strategies, demographic information and zygosity assignment are explained for each sample. Pubmed abstract
The twin study at Helsinki University began in 1974, when the Older cohort studies were started. Later also Finntwin16 and Finntwin12 studies have been initiated. The follow-up study has been proceeded to this day with three baseline projects. Several studies have also been completed to some smaller cohorts. Currently we are cooperating with many Finnish and foreign researchers.
Italian Twin Registry - ITR
The Italian Twin Registry is a population register comprising pairs of twins who accept to participate in medical and scientific research activities aimed at improving the health of the whole population. It was created in 2000 and today it is a well-established scientific reality involving more than 9000 twins.
Mid-Atlantic Twin Registry - MATR
The Mid-Atlantic Twin Registry is a population-based registry of 50,000+ twins of all ages who were born in or live in North Carolina, South Carolina, and Virginia.
The Minnesota Center for Twin and Family Research (MCTFR) is primarily composed of two studies: the Minnesota Twin Family Study (MTFS) and the Sibling Interaction and Behavior Study (SIBS). Both projects are longitudinal research studies including twins, siblings, and parents. Over 9800 individuals have contributed to these exciting projects! By studying twins and siblings and their families, we can estimate how genes and environment interact to influence character, strengths, vulnerabilities and values.
NMTR - National Malaysian Twin Registry
National Malaysian Twin Registry (NMTR) is a non-profit organization which facilitates scientific research involving participation of twins or their family members in order to answer some of the questions of health and wellbeing relevant to Malaysians.
Netherlands Twin Register - NTR
The Netherlands Twin Register now contains the details of nearly 40,000 twin pairs and other multiples. Every segment of the population is represented.
The Norwegian Twin Registers consist of several population based sub-registries and cover twins born between 1895 and present. Three separate cohorts can be distinguished: 1895-1945 (Kringlen 16), 1915-1960 (Magnus 17), and 1967-present (Harris 18). The middle cohort comprises only like-sex pairs. The birth cohorts from 1960 to 1967 are not registered. Zygosity has been determined by similarity questions and in some cases confirmed by DNA testing. Pubmed abstract
Southern California Twin Project
The Southern California Twin Project at USC coordinates a series of research studies of twins. The primary goal of this research is to understand the roles of heredity (genes) and environment (culture) in producing individual differences in human behavior. Topics of investigation include personality, cognitive abilities, mate selection, antisocial behavior and delinquency.
National Twin Register of Sri Lanka - NTR
The Sri Lankan Twin registry established in 1996 is the first ever twin register in South Asia. It is still one the of few large scale functional population based twin registries in developing world. Two main twin cohorts are volunteer and population based. The population based twin register is presently confined to Colombo district; the most populous among the 25 administrative districts of Sri Lanka.
The Department of Twin Research & Genetic Epidemiology at St. Thomas' Hospital was set up in 1992 at St Thomas’ Hospital mainly via grants from The Wellcome Trust and Arthritis Research Campaign among others. It now contains a voluntary database of 10,000 identical and non identical, mostly female twins, from across the UK between the ages of 16 and 85 years of age – with a mean age of 48. It is now the UK’s only adult twin registry and is the most detailed clinical adult register in the world.
Swedish Twin Registry is the largest twin register in the world and includes more than 140,000 twins. The registry covers three different age cohorts, the older cohort, the middle cohort, and the younger cohort. The purpose of twin studies is to study the relative importance of genetic and environmental influences for behavioral characteristics and diseases.