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

OBJECTIVES: This study sought to determine the rate of familial 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.