title: Increased rate of twins among affected sibling pairs with autism.
authors.forename: Catalina
authors.initials: C
authors.lastname: Betancur
authors.forename: Marion
authors.initials: M
authors.lastname: Leboyer
authors.forename: Christopher
authors.initials: C
authors.lastname: Gillberg
mesh_terms: D001321:Autistic Disorder / Q000453:epidemiology / Q000209:etiology / Q000235:genetics*; D015331:Cohort Studies; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics*; D006801:Humans; D018401:Sample Size; D015983:Selection Bias; D014427:Twins / Q000235:genetics / Q000706:statistics & numerical data