11β-hydroxylase deficiency pathophysiology

Pathogenesis

11β-Hydroxylase deficient congenital adrenal hyperplasia (11β-OH CAH) is an uncommon form of congenital adrenal hyperplasia (CAH) resulting from a defect in the gene encoding the enzyme steroid 11β-hydroxylase which mediates the final step of cortisol synthesis in the adrenal. 11β-OH CAH results in hypertension due to excessive mineralocorticoid effects. It also causes excessive androgen production both before and after birth and can virilize a genetically female fetus or a child of either sex. 11β-OH congenital adrenal hyperplasia resembles 21-hydroxylase deficient CAH in its androgenic manifestations: partial virilization and ambiguous genitalia of genetically female infants, childhood virilization of both sexes, and rarer cases of virilization or infertility of adolescent and adult women. The mineralocorticoid effect differs: hypertension is usually the clinical clue that a patient has 11- rather than 21-hydroxylase CAH. Diagnosis of 11β-OH congenital adrenal hyperplasia is usually confirmed by demonstration of marked elevations of 11-deoxycortisol and 11-deoxycorticosterone (DOC), the substrates of 11β-hydroxylase. Management is similar to that of 21-hydroxylase deficient congenital adrenal hyperplasia except that mineralocorticoids need not be replaced.

References

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