Defective CYP11B1 causes AH4

Cytochrome P450 11B1, mitochondrial (CYP11B1) possesses steroid 11-beta-hydroxylase activity which can convert 11-deoxycortisol to cortisol. 11-beta-hydroxylase deficiency is one of the main causes of congenital adrenal hyperplasia (CAH) (5-8%), second only to 21-hydroxylase deficiency which accounts for more than 90% of CAH. Defects in CYP11B1 can cause Adrenal hyperplasia 4 (AH4; MIM:202010), a form of congenital adrenal hyperplasia which is a common recessive disease due to failure to convert 11-deoxycortisol to cortisol. This impaired corticosteroid biosynthesis results in androgen excess, virilization and hypertension.

Summary from Reactome (R-HSA-5579017), read 2026-09-23.