Twin registries in foreign countries: an overview

Abstract

The aim of this study is to clarify how many twin registers are there in foreign countries. This paper also gives an overview of existing twin registers. Twin registers were searched using MEDLINE, with key word ?etwin register' or ?etwin registry' from 1997 to 2002. The international journal of ?eTwin Research' was also searched, from 1998 to 2002, to reinforce information. In our definition of a twin register, we did not impose any limitation as to sample size or depth of data. The results were following; in 749 articles we ascertained 56 twin registers in total. For the current overview, we included large population-based registers with more than 10, 000 pairs, as well as yet growing specific collections of less than a hundred pair. Twin registers have been exist in many European countries, such as Scandinavia, Germany, Belgium, the UK, Italy, The Netherlands, as well as many states of the United States and Australia. In Italy and several Asian countries, such as Sri Lanka, China, and Korea, a large nationwide register has also been under establishment. The aim of establishing twin register ranged from various researches in human genetics to maternal and child health. These findings supported that it is important to examine the establishment of twin register in Japan.