Clinical and molecular characterization of patients with classic 3β-hydroxysteroid dehydrogenase deficiency

Background 3b-hydroxysteroid dehydrogenase type 2 (3bHSD2) is the key enzyme converting Δ5-steroids to Δ4-ketosteroids in adrenal and gonadal steroidogenesis. Severe lossof-function mutations of HSD3B2 gene encoding for this enzyme cause the rare form of congenital adrenal hyperplasia, “3bHSD deficiency”. Affected individuals have salt losing, adrenal insufficiency and ambiguous genitalia in both sexes. Patients with 3bHSD deficiency may have elevated 17a-hydroxyprogesterone (17OHP) levels due to normal peripheral type 1, 3bHSD.