A PROSPECTIVE-STUDY TO ASSESS THE FREQUENCY OF FAMILIAL CLUSTERING OFCONGENITAL BICUSPID AORTIC-VALVE

Objectives. This study sought to determine the rate of familiar occurr ence of congenital bicuspid aortic valve (BAV) by using echocardiograp hy to screen family members. Background. Congenital BAV is a common an omaly that carries with it a significant risk of potential long-term c ardiac complications. Despite several reports of the familial occurren ce of BAV, the condition is not generally considered to be inherited. Methods. Thirty consecutive patients with echocardiographically docume nted congenital BAV were interviewed to construct three-generation fam ily pedigrees. All first-degree relatives were contacted to undergo ec hocardiography to specifically determine aortic valve morphology. Resu lts. Of the 210 first-degree relatives, 190 (90.5%) agreed to undergo echocardiography. Four members had technically difficult studies. Of t he remaining 186 subjects, 17 (9.1%) were identified as having BAV; 11 (36.7%) of the 30 families had at least one additional member with th e condition. The male/female ratio of affected members in the 11 famil ies was 1. In one family, two instances of male to-male transmission w ere observed. The distribution of BAV in the majority of multiplex fam ilies is compatible with autosomal dominant inheritance, with reduced penetrance. Conclusions. We demonstrated a high incidence of familial clustering in congenital BAV. We believe that the high rate of occurre nce of the condition in immediate relatives justifies echocardiographi c screening of first-degree relatives to anticipate and prevent future complications associated with this common cardiac malformation. (C) 1 997 by the American College of Cardiology.