This is a supplement to project 5R01MH074090-08. Neurodevelopmental disorders, including intellectual disabilities and autism spectrum disorders (ASDs), are very common, affecting ~3% of the population. Recent evidence indicates remarkable genetic heterogeneity in what causes these disorders with a major role for rare copy number variations or CNVs (submicroscopic deletions or duplications of DNA). In this study, researchers will identify specific autism genes by performing comprehensive mutation analysis in well-phenotyped autistic patients from publicly available sources (e.g., Simons Simplex Collection, Autism Genetics Resource Exchange, and the NIMH repositories). Researchers hope to develop a novel, cost-effective strategy to leverage the CNV and phenotype data from tens of thousands of clinical diagnostic tests performed on children with neurodevelopmental disorders each year in the United States to identify the critical regions of the genome and individual genes responsible for these intellectual disabilities and ASDs.