Steroid 11 beta-hydroxylase deficiency and related disorders.

Steroid 11 beta-hydroxylase deficiency is the second most frequent cause of congenital adrenal hyperplasia, the inherited inability to synthesize cortisol. About two thirds of patients with this disorder have hypertension, presumably due to elevated levels of deoxycorticosterone or other metabolites. Signs of androgen excess also often are prominent. This disease is caused by mutations in the CYP11B1 gene, which encodes a mitochondrial cytochrome P450 enzyme. The main treatment is glucocorticoid replacement, which suppresses excessive secretion of mineralocorticoids and androgens by the adrenal cortex.