Summary

Williams Syndrome (WS) is a rare condition resulting from the deletion of approximately 25 genes on one copy of chromosome 7. As well as physical manifestations, most individuals with WS have a distinctive psychological profile including marked difficulties in visuospatial cognition, relatively fluent speech, and good face recognition, and a “hypersocial” personality including intense attention to faces and readiness to approach and engage with strangers. However, they show wide individual variations in cognitive and social abilities, from severe intellectual disability to normal range IQ scores. Many individuals with WS are prone to anxiety and obsessions and some meet the criteria for attention deficit hyperactivity disorder. A number of features of the WS profile are consistent with a deficit in function of the dorsal cortical stream, and anomalies in dorsal stream structures, as well as other specific features of brain structure and function which have been identified in the brains of individuals with WS. A number of specific genes within the deletion have been characterized, and links between gene expression, neural structure, and behavior have been suggested, but understanding of these links remains very partial and uncertain. Individuals with WS display a friendly and engaging personality. However, their social and cognitive difficulties mean that specialist support is needed in their education and integration within the community so that people with WS can achieve a degree of independent living while optimizing their well-being.