The goal of the project is to recruit 200 individuals with an autism spectrum disorder (ASD) and 100 demographically matched controls for derivation of induced pluripotent stem cells (iPSCs). The cells will be deposited in a biorepository and made available to other researchers upon request.. ASDs have a worldwide prevalence of 1% (>1.5 million in the US) and a lifetime cost per affected individual of $3.2M. ASDs are amongst the most heritable of psychiatric disorders. Genome Wide Association studies utilizing samples in the thousands provide only weak evidence for common allele risk effects; positive findings rarely replicate, and genetic effects sizes are small (odds ratios of ~1.1). In contrast, evidence to date for risk or causation conferred by rare variation, particularly rare copy number variants, is very strong. Pathway analyses of the rare mutations implicated and genome-wide transcriptome analysis of brain and blood tissue provide converging evidence that neural-related pathways are central to the development of autism. Core impairments of ASDs, such as imagination and curiosity about the environment, cannot be modeled well in other organisms. The mechanisms underlying ASDs need to be studied in humans and cells that share the genetic background of the patients, such as neurons from patients derived from induced pluripotent cell lines (iPSC). Recruitment of participants occurred through the Autism and Developmental Disabilities Clinic (ADDC) at Stanford University, direct referrals to investigators, through the Stanford autism research registry, from completed and ongoing research studies, and through advertisement on the web and print. To date we have recruited 181 subjects of the 300 total.