William's syndrome

In medicine, a rare genetic disorder arising from the loss of a tiny segment from chromosome 7. It is characterized by an average IQ of 60, elfin facial features, shortness of stature, hoarseness of voice, slight premature ageing, and cardiovascular problems. Despite their low IQ, they exhibit a facility for spoken language and frequently exhibit exceptional musical ability. Incidence worldwide is 1 in 20,000 births.

The syndrome was first described in 1961 by New Zealand cardiologist J C P Williams.