7 - A GENETIC FIRST APPROACH TO DISSECTING THE HETEROGENEITY OF AUTISM: PHENOTYPIC COMPARISON OF AUTISM RISK COPY NUMBER VARIANTS

Abstract

Background Autism is a heterogeneous condition and there is growing evidence that different features are dissociable and may be underpinned by different risk factors. Several autism risk copy number variants (CNVs) have been identified. It remains unclear whether these CNVs differentially impact autism presentation. This study aimed to contrast autism symptomatology and the clinical profile of different autism risk CNVs. Methods Patients were recruited at several international sites based on genotype, not autism phenotype. This work represents the efforts of several consortia; the ECHO study, IMAGINE-ID consortium, International 22q11.2DS Brain Behaviour Consortium, 16p11.2 European Consortium and Simons VIP. Patients were all assessed using the Autism Diagnostic Interview-Revised (ADI-R) and underwent IQ testing. We focused on 16p11.2 deletion (n=96), 16p11.2 duplication (n=47), 22q11.2 deletion (n=383) and 22q11.2 duplication (n=22) carriers. Patients were aged 4–27 years. We examined autism prevalence based on ADI-R criteria, ADI-R domain scores, whether carriers with autism had additional IQ deficits and autism male-to-female ratio. Results Autism prevalence differed by syndrome (p Discussion Autism risk genetic variants have specific genotype-phenotype correlations. This indicates that autism is dissociable at the genetic level, and supports the view that different biological pathways underpin distinct symptom domains.