11β-hydroxylase deficiency

11β-hy·drox·y·lase de·fi·cien·cy (hi-drokґsə-lās) an autosomal recessive disorder of steroidogenesis caused by a mutation in the CYP11B1 gene (locus: 8q21), which encodes steroid 11β-monooxygenase; the resulting enzyme deficiency causes classic and nonclassic forms of one type of congenital adrenal hyperplasia (type IV). In the classic (hypertensive) form, the enzyme deficiency results in increased levels of cortisol precursors such as 11-deoxycortisol and the salt-retaining hormone 11-deoxycorticosterone, and decreased cortisol and aldosterone synthesis. Clinical manifestations include hypertension and, due to increased androgens, female pseudohermaphroditism and postnatal virilization of both sexes. The nonclassic (late onset) form is milder, and patients are frequently normotensive. See table at hyperplasia.