Familial discrete subaortic stenosis.

Discrete subaortic stenosis (DSS) accounts for 8 to 20% of all cases of congenital left ventricular outflow tract obstruction. There have been few scattered reports of left ventricular obstructive lesions occurring in immediate family members of patients with DSS. This is a report of four cases of DSS in one family: one brother with a fibrous ring, and two sisters and the son of one of the sisters with a fibrous membrane. The occurrence of multiple cases of DSS in this family suggests an autosomal dominant mode of inheritance.