How many people are affected by 21-hydroxylase deficiency ?
The classic forms of 21-hydroxylase deficiency occur in 1 in 15,000 newborns. The prevalence of the non-classic form of 21-hydroxylase deficiency is estimated to be 1 in 1,000 individuals. The prevalence of both classic and non-classic forms varies among different ethnic populations.  21-hydroxylase deficiency is one of a group of disorders known as congenital adrenal hyperplasias that impair hormone production and disrupt sexual development. 21-hydroxylase deficiency is responsible for about 95 percent of all cases of congenital adrenal hyperplasia.