Research has shown that genetic changes play a major role in autism. Reports estimate that 5-28% of individuals with autism have chromosome anomalies, and this wide range depends on whether subjects have physical abnormalities and/or cognitive delay. Thus, the collection of specific chromosomal anomalies in any one individual may correlate with their particular form of autism. For this reason, it is essential to identify subgroups within autism in order to put into context the inventory of autism-related chromosome defects. By applying a new screening method to people with complex forms of autism that include physical deformities with or without intellectual disability, Dr. Lewis and colleagues have found previously unknown genomic changes in autism. Dr. Lewis' post-doctoral fellow will apply this screening method to additional subjects with both complex and simple forms of autism, in collaboration with the Genetics Team of the Autism Spectrum Disorders Canadian-American Research Consortium (ASD-CARC). This study will characterize chromosomal anomalies with respect to their parent of origin, size, breakpoints, association with flanking sequence variations, selected candidate genes, and their presence in controls and the broader autism population. More refined phenotype information will also be collected, including measurements of craniofacial morphology, in order to associate genetic findings with specific autism subgroups. What this means for people with autism: This study will help make sense of the large number of chromosomal anomalies related to autism by sorting out how these genetic changes segregate according to complex or simple forms of autism. These specific genetic profiles will eventually allow earlier and more accurate diagnosis.