title: Social cognition and underlying cognitive mechanisms in children with an extra X chromosome: a comparison with autism spectrum disorder.
abstract: Individuals with an extra X chromosome are at increased risk for autism symptoms. This study is the first to assess theory of mind and facial affect labeling in children with an extra X chromosome. Forty-six children with an extra X chromosome (29 boys with Klinefelter syndrome and 17 girls with Trisomy X), 56 children with autism spectrum disorder (ASD) and 88 non-clinical controls, aged 9-18 years, were included. Similar to children with ASD, children with an extra X chromosome showed significant impairments in social cognition. Regression analyses showed that different cognitive functions predicted social cognitive skills in the extra X and ASD groups. The social cognitive deficits were similar for boys and girls with an extra X chromosome, and not specific for a subgroup with high Autism Diagnostic Interview Revised autism scores. Thus, children with an extra X chromosome show social cognitive deficits, which may contribute to social dysfunction, not only in children showing a developmental pattern that is 'typical' for autism but also in those showing mild or late presenting autism symptoms. Our findings may also help explain variance in type of social deficit: children may show similar social difficulties, but these may arise as a consequence of different underlying information processing deficits.
authors.affiliation: Clinical Child and Adolescent Studies, Leiden University.|Leiden Institute for Brain and Cognition.
authors.forename: S
authors.initials: S
authors.lastname: van Rijn
authors.affiliation: Clinical Child and Adolescent Studies, Leiden University.|Autism Center Rivierduinen, Leiden, The Netherlands.
authors.forename: L
authors.initials: L
authors.lastname: Stockmann
authors.affiliation: Center for Human Genetics, University Hospital of Leuven, Leuven, Belgium.
authors.forename: G
authors.initials: G
authors.lastname: van Buggenhout
authors.affiliation: Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: C
authors.initials: C
authors.lastname: van Ravenswaaij-Arts
authors.affiliation: Clinical Child and Adolescent Studies, Leiden University.|Leiden Institute for Brain and Cognition.
authors.forename: H
authors.initials: H
authors.lastname: Swaab
mesh_terms: D000293:Adolescent; D000067877:Autism Spectrum Disorder / Q000175:diagnosis / Q000503:physiopathology*; D002648:Child; D041321:Chromosomes, Human, X; D003071:Cognition; D056348:Emotional Intelligence; D005260:Female; D006801:Humans; D008297:Male; D012729:Sex Chromosome Aberrations; D058533:Sex Chromosome Disorders of Sex Development / Q000175:diagnosis / Q000503:physiopathology*; D012919:Social Behavior; D014314:Trisomy / Q000175:diagnosis / Q000503:physiopathology*
keywords: Autism; Klinefelter; Trisomy X; facial expressions; theory of mind