Hypoplastic Left Heart Syndrome Is Heritable

Hypoplastic Left Heart Syndrome Is Heritable Robert B. Hinton, Jr, Lisa J. Martin, Meredith E. Tabangin, Mjaye L. Mazwi, Linda H. Cripe, D. Woodrow Benson Familial clustering of hypoplastic left heart syndrome (HLHS) and bicuspid aortic valve has been documented suggesting a genetic basis. To determine the size of the genetic effect, we used a sequential sampling strategy in 38 HLHS families and estimated heritability (h2 ) of HLHS and associated cardiovascular malformation using variance decomposition. The heritability of HLHS alone and with associated cardiovascular malformation was 99% and 74% (p < 0.00001), suggesting that HLHS is determined primarily by genetic factors. Valve dysplasia in HLHS probands and bicuspid aortic valve in relatives suggests that HLHS is a form of valve malformation.