A twin study investigating the genetic and environmental aetiologies of parent, teacher and child ratings of autistic-like traits and their overlap.

Social Genetic and Developmental, Psychiatry (SGDP) Centre, Institute of Psychiatry, De Crespigny Park, London, UK. a.ronald@iop.kcl.ac.uk

In the present study we investigated phenotypic agreement between informants (parent, teacher and child self-report) on ratings of autistic-like traits and compared the genetic and environmental aetiologies of the informants' ratings and of their covariance. Parents and teachers of >2,500 pairs from a community twin sample completed an abbreviated Childhood Asperger Syndrome Test (CAST). The twins also completed an adapted self-report version of the CAST. Structural equation model-fitting was carried out. Correlations between raters were significant but moderate (0.16-0.33). The magnitude of heritability estimates of autistic-like traits varied across raters, being highest for parent-rated autistic-like traits (82-87%) and more modest for child self-reported autistic-like traits (36-47%). Genetic overlap was significant but moderate across all raters. These findings are discussed in relation to population screening for autism and future genetic research.

PMID: 18427861 [PubMed - indexed for MEDLINE]