Subgrouping siblings of people with autism: Identifying the broader autism phenotype.
We investigate the broader autism phenotype (BAP) in siblings of individuals with autism spectrum conditions (ASC). Autistic traits were measured in typical controls (n = 2,000), siblings (n = 496), and volunteers with ASC (n = 2,322) using the Autism-Spectrum Quotient (AQ), both self-report and parent-report versions. Using cluster analysis of AQ subscale scores, two sibling subgroups were identified for both males and females: a cluster of low-scorers and a cluster of high-scorers. Results show that while siblings as a group have intermediate levels of autistic traits compared to control individuals and participants with ASC, when examined on a cluster level, the low-scoring sibling group is more similar to typical controls while the high-scoring group is more similar to the ASC clinical group. Further investigation into the underlying genetic and epigenetic characteristics of these two subgroups will be informative in understanding autistic traits, both within the general population and in relation to those with a clinical diagnosis. Autism Res 2016, 9: 658-665. © 2015 The Authors Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research.
Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|Department of Psychiatry, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.
Emily
E
Ruzich
Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|NIHR CLAHRC for the East of England, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.
Carrie
C
Allison
Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.
Paula
P
Smith
MRC Cognition and Brain Sciences Unit, 15 Chaucer Road, Cambridge, CB2 7EF, UK.
Peter
P
Watson
Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|Department of Psychology, School of Philosophy, Psychology and Language Sciences, University of Edinburgh, 7 George Square, Edinburgh, EH9 1JD, UK.
Bonnie
B
Auyeung
Department of Psychiatry, Cambridge Intellectual and Developmental Disabilities Research Group, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|NIHR CLAHRC for the East of England, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|Cambridgeshire and Peterborough NHS Foundation Trust, Peterborough, CB21 5EF, UK.
Howard
H
Ring
Department of Psychiatry, Autism Research Centre, University of Cambridge, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|NIHR CLAHRC for the East of England, Douglas House, 18B Trumpington Road, Cambridge, CB2 8AH, UK.|CLASS Clinic, Cambridgeshire and Peterborough NHS Foundation Trust, Peterborough, CB21 5EF, UK.
Simon
S
Baron-Cohen
D000293:Adolescent; D001321:Autistic Disorder / Q000175:diagnosis* / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D006801:Humans; D008297:Male; D010290:Parents; D010641:Phenotype; D057566:Self Report; D035781:Siblings / Q000523:psychology*
Autism-Spectrum Quotient; autism; autistic traits; broader autism phenotype; sex differences; siblings