A prospective study to assess the frequency of familial clustering of congenital bicuspid aortic valve

Objectives. This study sought to determine the rate of familiar occurrence of congenital bicuspid aortic valve (BAV) by using echocardiography to screen family members. Background. Congenital BAV is a common anomaly that carries with it a significant risk of potential long-term cardiac complications. Despite several reports of the familial occurrence of BAV, the condition is not generally considered to be inherited. Methods. Thirty consecutive patients with echocardiographically documented congenital BAV were interviewed to construct three-generation family pedigrees. All first-degree relatives were contacted to undergo echocardiography to specifically determine aortic valve morphology. Results. Of the 210 first-degree relatives, 190 (90.5%) agreed to undergo echocardiography. Four members had technically difficult studies. Of the 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 the condition. The male/female ratio of affected members in the 11 families was 1. In one family, two instances of male to-male transmission were observed. The distribution of BAV in the majority of multiplex families 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 occurrence of the condition in immediate relatives justifies echocardiographic screening of first-degree relatives to anticipate and prevent future complications associated with this common cardiac malformation. (C) 1997 by the American College of Cardiology.