Mitral regurgitation without supravalvular aortic stenosis in Williams syndrome.

Isolated mitral regurgitation without supravalvular aortic stenosis is rarely identified in Williams syndrome. We describe the case of a 24-year-old man with isolated mitral regurgitation in Williams syndrome. Severe regurgitation due to prolapse of the anterior leaflet was noted in an echocardiogram and color Doppler, and a left ventriculogram showed grade IV regurgitation. No pressure gradient between the left ventricle and the ascending aorta was found. Mitral regurgitation had been noted since his birth, and pediatricians suspected Williams syndrome because of postnatal growth deficiency, mental deficiency, unusual personality, and unusual facial features in his childhood. The diagnosis was confirmed by demonstration of the hemizygous deletion of 7q11.23 in the karyotype by the fluorescent in situ hybridization technique after his admission to our department. The patient underwent mitral valve replacement, and microscopic examination of the excised valve revealed myxomatous degeneration.