"Well, I'll bet she has a supravalvular aortic stenosis, of course."

Individuals with Williams syndrome experience many cardiac problems, commonly heart murmurs and the narrowing of major blood vessels as well as supravalvular aortic stenosis.

All suffer from a heart defect called supravalvular aortic stenosis, or SVAS, in varying degrees of severity.

Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS) and autosomal dominant cutis laxa.

Williams syndrome is a well described birth defect complex characterized by FTT, branch pulmonary artery stenosis, supravalvular aortic stenosis, dysmorphic facies, mental retardation, and infantile hypercalcemia.

Researchers have found that loss of the ELN gene, which codes for the protein elastin, is associated with the connective-tissue abnormalities and cardiovascular disease (specifically supravalvular aortic stenosis and supravalvular pulmonary stenosis) found in many people with this syndrome.

Williams syndrome was first described by Dr. J.C.P. Williams and his colleagues, who wrote in 1961 of four patients with supravalvular aortic stenosis, mental disability, and facial features including a broad forehead, large chin, low-set, "drooping" cheeks, widely spaced eyes, and a wide-set mouth.