Supravalvular aortic stenosis, pulmonary artery stenosis, and coronary artery stenosis in twins.

Supravalvular aortic stenosis (SVAS) is rare in twins. We report monozygotic twins, both of whom had SVAS, coronary ostial stenosis, and peripheral pulmonary arterial stenosis, but no other phenotypic features of Williams syndrome. One of the twins died suddenly, but the SVAS and the right and left coronary ostial stenoses were enlarged successfully at operation in the other twin.