title: A twin study of autism in Denmark, Finland, Iceland, Norway and Sweden.
abstract: The Nordic countries were screened for the occurrence of cases of autism with a same-sexed twin under age 25 years. Twenty-one pairs (11 monozygotic and 10 dizygotic) of twins and one set of identical triplets were found and extensively examined. The concordance for autism by pair was 91% in the monoygotic and 0% in the dizygotic pairs. The corresponding concordances for cognitive disorder were 91% and 30%, respectively. In most of the pairs discordant for autism, the autistic twin had more perinatal stress. The results lend support for the notion that autism sometimes has a hereditary component and that perinatal stress is involved in some cases.
authors.affiliation: Department of Child and Adolescent Psychiatry, University of Göteborg, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Steffenburg
authors.forename: C
authors.initials: C
authors.lastname: Gillberg
authors.forename: L
authors.initials: L
authors.lastname: Hellgren
authors.forename: L
authors.initials: L
authors.lastname: Andersson
authors.forename: I C
authors.initials: IC
authors.lastname: Gillberg
authors.forename: G
authors.initials: G
authors.lastname: Jakobsson
authors.forename: M
authors.initials: M
authors.lastname: Bohman
mesh_terms: D000293:Adolescent; D000328:Adult; D001321:Autistic Disorder / Q000235:genetics* / Q000523:psychology; D001925:Brain Damage, Chronic / Q000235:genetics; D002648:Child; D002653:Child Behavior Disorders / Q000235:genetics; D002675:Child, Preschool; D004200:Diseases in Twins; D005260:Female; D005600:Fragile X Syndrome / Q000235:genetics; D006801:Humans; D007055:Iceland; D007859:Learning Disabilities / Q000235:genetics; D008297:Male; D012307:Risk Factors; D012537:Scandinavian and Nordic Countries; D012931:Social Environment; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic