21-Hydroxylase Deficiency overview
Congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OH CAH), in all its forms, accounts for about 95% of diagnosed cases of congenital adrenal hyperplasia, and "CAH" in most contexts refers to 21-hydroxylase deficiency.
- Severe 21-hydroxylase deficiency causes salt-wasting CAH, with life-threatening vomiting and dehydration occurring within the first few weeks of life. Severe 21-hydroxylase deficiency is also the most common cause of ambiguous genitalia due to prenatal virilization of genetically female (XX) infants.
- Moderate 21-hydroxylase deficiency is referred to as simple virilizing CAH; and typically is recognized as causing virilization of prepubertal children.
- Still milder forms of 21-hydroxylase deficiency are referred to as non-classical CAH and can cause androgen effects and infertility in adolescent and adult women.