Williams syndrome

Williams Syndrome is a rare genetic disorder, occurring in fewer than 1 in every 20,000 live births. It is characterized by a distinctive, "elfin" facial appearance, an unusually cheerful demeanor, ease with strangers, mental retardation coupled with an unusual facility with language, a love for music, cardiovascular problems such as aortic stenosis[?], and hypercalcemia[?]. Most children with Williams Syndrome are missing genetic material on chromosome 7.