title: The Danish Twin Registry.
abstract: BACKGROUND
  The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases.
  
  
  BACKGROUND
  More than 85,000 twin pairs born 1870-2008 in Denmark.
  
  
  RESULTS
  Four main ascertainment methods have been employed. Completeness of ascertainment varies according to birth cohorts. For birth cohorts 1870-1930 both twins should survive to age 6 years. From 1931-1968 72% of all twin pairs has been ascertained, with complete ascertainment of all live born twins since 1968.
  
  
  CONCLUSIONS
  Because twins have been identified independent of traits and on a population basis, the Danish Twin Registry is well suited for studies to understand the influence of genetic and environmental factors for a wide variety of diseases and traits.
authors.affiliation: The Danish Twin Registry, Epidemiology, Institute of Public Health, University of Southern Denmark, Odense, Denmark. askytthe@health.sdu.dk
authors.forename: Axel
authors.initials: A
authors.lastname: Skytthe
authors.forename: Kirsten Ohm
authors.initials: KO
authors.lastname: Kyvik
authors.forename: Niels Vilstrup
authors.initials: NV
authors.lastname: Holm
authors.forename: Kaare
authors.initials: K
authors.lastname: Christensen
mesh_terms: D000328:Adult; D002648:Child; D003718:Denmark / Q000453:epidemiology; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D012042:Registries / Q000592:standards; D014427:Twins / Q000235:genetics