This proposal advances that this Center, that while new, has an exceptionally strong history and expertise in characterizing genetic and environmental influences on IDD, with a focus on: preventing or ameliorating pathogenic mechanism of structural and functional abnormalities of brain development. Herein we propose to leverage the collaborative and innovatic excellence of the UCSF IDDRC and the broader UCSF environment, including unparallelled experience in probing the range of behavioral phenotypes, a broad and longstanding expertise in neuroimaging, both in the implementation of imaging to elucidate behaviorally linked disorders as well as single gene/genetic locus disorders. We also have cutting edge genetics both in idiopathic developmental disorders (such as autism) and in the characterization of structural malformations of brain development, which synergistically provide insight into not only genetic etiologies but focused investigation of single gene/genetic locus disorders.