Risk of sudden death in the Williams-Beuren syndrome.

Williams-Beuren syndrome (WBS) is a genetic disorder characterized by a distinctive facial gestalt, mental retardation, mild growth deficiency, and cardiovascular disease. The occurrence of sudden death in the WBS is known from several case reports, but information about the risk of sudden death as derived from the data of a large cohort of patients is lacking. We analyzed the data of 293 WBS patients who had been treated for 43 years at the same two institutions. We thus collected 5,190 patient years without loss to follow-up. During this period ten patients died. Five of them died from: reticulosarcoma (1), after accident (1), heart failure (1), following heart surgery (2). Of the remaining five patients, four died suddenly and one died of unknown cause suggestive of sudden cardiac death. Thus, the incidence of sudden death in our WBS cohort amounts to 1/1,000 patient years. This risk of sudden death is comparable to that following surgery for congenital heart disease, and is 25-100-fold higher compared to the age-matched normal population.