The bicuspid aortic valve: adverse outcomes from infancy to old age.

The population frequency of a bicuspid aortic valve is 0.9% to 1.36%,1–3 with a 2:1 male:female ratio. It is likely that the presence of a bicuspid aortic valve has a genetic basis, with the pattern of transmission in some families suggesting an autosomal dominant pattern of inheritance.4,5 Epidemiological data from the BaltimoreWashington Infant Study demonstrated the familial clustering of left heart obstructive lesions (including coarctation of the aorta, aortic valve stenosis, and hypoplastic left heart syndrome).6 More recently, the increased risk of identifying a bicuspid aortic valve in the parent or sibling of the proband with any form of left heart obstructive lesion was described.7 By inference, this also suggests the potential identification of a congenitally malformed aortic valve in the presence a family member with a more complex congenital heart lesion. In addition, a bicuspid aortic valve is present in 50% of patients with aortic coarctation8 and in 10% to 12% of women with Turner syndrome.9 The specific genetic locus and protein abnormality in patients with a bicuspid aortic valve have not yet been identified, however.