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Developmental path between language and autistic‐like impairments: a twin study
Author(s) -
Dworzynski Katharina,
Ronald Angelica,
HayiouThomas Marianna E.,
McEwan Fiona,
Happé Francesca,
Bolton Patrick,
Plomin Robert
Publication year - 2008
Publication title -
infant and child development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.87
H-Index - 57
eISSN - 1522-7219
pISSN - 1522-7227
DOI - 10.1002/icd.536
Subject(s) - autism , psychology , developmental psychology , autistic traits , twin study , language development , population , association (psychology) , asperger syndrome , path analysis (statistics) , autism spectrum disorder , heritability , genetics , demography , statistics , mathematics , sociology , biology , psychotherapist
Abstract Autism spectrum disorders (ASDs) are diagnosed when individuals show impairments in three behavioural domains: communication, social interactions, and repetitive, restrictive behaviours and interests (RRBIs). Recent data suggest that these three sets of behaviours are genetically heterogeneous. Early language delay is strongly associated with ASD, but the basis for this association and the relationship with individual sub‐domains of ASD has not been systematically investigated. In the present study, data came from a population‐based twin sample with language development data at 2–4 years, measured by the MacArthur Communicative Development Inventory (MCDI), and data at 8 years using the Childhood Asperger Syndrome Test (CAST). For the total CAST and the three subscales at 8 years, approximately 300 same‐sex twin pairs were selected as showing extreme autistic‐like traits (ALTs), defined here as pairs in which at least one member of the twin pair scored in the highest 5% of the distribution. Phenotypic analyses indicated that children showing extreme social and communication ALTs (but not the RRBI subscale) at 8 years were below average in language development at 2–4 years. A regression model for selected twin data suggested that genetic influences account for this overlap, but that these effects are only in part mediated by genes that are shared between language and extreme autistic traits. Copyright © 2008 John Wiley & Sons, Ltd.