Hypospadias in successive generations - possible dominant gene inheritance

Two families were ascertained with multiple cases of hypospadias. In one family, four generations were reported to be affected and this was proven in three generations. In the second family, a father and two sons were affected. We suggest that dominant gene inheritance may be responsible for a small number of hypospadias cases. The incidence of hypospadias in British Columbia is 1 per 250 live male births and, using Edwards' formula, this gives a theoretical empiric recurrence risk of about 6%.