Neurodevelopmental and behavioral issues in Williams syndrome.

Much existing research on Williams syndrome (WS) has focused on the individuals' unusual cognitive profile, with less emphasis placed on the developmental and neural underpinnings of the disorder. We review recent findings from brain imaging and begin to discuss links from these data to the behavioral phenotype. Overall brain size is significantly reduced in individuals with WS, as it is in many mental retardation syndromes. However, the specific profile of deficits in WS, particularly the visuospatial deficits, appears to be linked to parietal lobe abnormalities. Results from both genetic and brain imaging studies have provided useful insights into WS neurobiology. However, future work needs to remediate the lack of studies investigating developmental processes.