Williams Syndrome and Autism

Abstract

Abstract Certain human disorders, such as Williams syndrome (WS) and autism spectrum disorders (ASD), are known to affect social behaviors. WS is a rare neurodevelopmental disorder caused by deletion of approximately 25 genes on chromosome band 7q11.23, and WS individuals are typically described as hypersocial. ASD is a much more common group of heterogeneous disorders generally characterized by hyposociality. In WS total brain volume is decreased, while in ASD total brain volume is increased, in early development. Both disorders are characterized by microstructural changes throughout the brain, and this chapter focuses on changes in the prefrontal cortex and amygdala, regions which have been subject to recent evolutionary change in humans. This chapter reviews the neuroanatomical profiles of these two disorders in an evolutionary context before concluding with a brief discussion of how animal and stem cell models can be used to explore the cellular and molecular mechanisms underlying their neuroanatomical profiles.