Williams syndrome (WS), also known as Williams–Beuren syndrome (WBS), is a rare neurodevelopmental disorder characterized by: a distinctive, "elfin" facial appearance, along with a low nasal bridge; an unusually cheerful demeanor and ease with strangers; developmental delay coupled with strong language skills; profound visuo-spatial impairments; and cardiovascular problems, such as supravalvular aortic stenosis and transient high blood calcium.

It is caused by a deletion of about 26 genes from the long arm of chromosome 7.[1][2] It occurs in 1 in 7,500 to 1 in 20,000 births.[2] The syndrome was first identified in 1961 by New Zealander J.C.P. Williams.[3][4]

  • Find out more