Non-classical congenital adrenal hyperplasia caused by 21-hydroxylase deficiency (NCCAH) is a milder and late-onset congenital adrenal hyperplasia. Its prevalence rate in different ethnic groups varies from 1 in  to 1 in . Some people affected by the condition have no relevant signs and symptoms, while others experience symptoms of hyperandrogenism.
Women with NCCAH usually have normal female genitalia at birth. In later life, the signs and symptoms of the condition may include acne, hirsutism, male-pattern baldness, irregular menstruation, and infertility.
Fewer studies have been published about males with NCCAH comparing to those about females, because males are generally asymptomatic. Males, however, may present with acne and early balding.
While symptoms are usually diagnosed after puberty, children may present with premature adrenarche.