1 Department of Clinical Medicine - Psychatric Hospital for Children and Adolescents, Department of Clinical Medicine, Health, Aarhus University2 Univ Southern Denmark, Dept Child & Adolescent Psychiat Odense3 Univ Southern Denmark, Inst Reg Hlth Serv Res4 Univ Southern Denmark, Dept Child & Adolescent Psychiat Odense5 Department of Clinical Medicine - Psychatric Hospital for Children and Adolescents, Department of Clinical Medicine, Health, Aarhus University
Genetic epidemiological studies of Autism Spectrum Disorders (ASDs) based on twin pairs ascertained from the population and thoroughly assessed to obtain a high degree of diagnostic validity are few. All twin pairs aged 3-14 years in the nationwide Danish Twin Registry were approached. A three-step procedure was used. Five items from the "Child Behaviour Checklist" (CBCL) were used in the first screening phase, while screening in the second phase included the "Social and Communication Questionnaire" and the "Autism Spectrum Screening Questionnaire". The final clinical assessment was based on "gold standard" diagnostic research procedures including diagnostic interview, observation and cognitive examination. Classification was based on DSM-IV-TR criteria. The initial sample included 7,296 same-sexed twin pairs and, after two phases of screening and clinical assessment, the final calculations were based on 36 pairs. The probandwise concordance rate for ASD was 95.2 % in monozygotic (MZ) twins (n = 13 pairs) and 4.3 % in dizygotic (DZ) twins (n = 23 pairs). The high MZ and low DZ concordance rate support a genetic aetiology to ASDs.
European Child and Adolescent Psychiatry, 2014, Vol 23, Issue 1, p. 35-43
Autism spectrum disorders; Twins; Concordance rates; Population based; Screening; PERVASIVE DEVELOPMENTAL DISORDERS; SOCIAL COMMUNICATION QUESTIONNAIRE; CHILD-PSYCHIATRIC-DISORDERS; DIAGNOSTIC INTERVIEW; SCREENING QUESTIONNAIRE; ENVIRONMENTAL-FACTORS; PRESCHOOL-CHILDREN; ASPERGER-SYNDROME; PREVALENCE; PAIRS; autism spectrum disorders; twins; screening; population based study