Apparent mineralocorticoid excess.

Apparent mineralocorticoid excess is a congenital syndrome of sodium retention and hypertension with suppressed renin and aldosterone and normal cortisol levels. Patients with the syndrome have, however, highly abnormal levels of urinary cortisol to cortisone metabolites, indicating a reduced or absent activity of 11 beta-hydroxysteroid dehydrogenase 2, the enzyme responsible for conversion of cortisol to receptor-inactive cortisone. Very recently, the gene for 11 beta-hydroxysteroid dehydrogenase 2 was cloned, and mutations leading to absent or markedly reduced enzyme activity were found in 10 or 11 patients to date.