A CASE OF APPARENT MINERALOCORTICOID EXCESS DUE TO 11-BETA-HSD2 DEFICIENCY

The syndrome of apparent mineralocorticoid excess is a recessively inh erited form of low renin hypertension. The syndrome is characterised b y sodium retention and hypervolemia despite low plasma renin activity, and aldosterone levels. Patients with this syndrome have mutations in the 11HSD2 gene which encodes the enzyme which normally converts cort isol in the renal tubule to its inactive form, cortisone. The unconver ted cortisol is thus able to bind and activate the mineralocorticoid r eceptor, displacing its usual ligand, aldosterone, causing the apparen t mineralocorticoid excess. We have studied a patient with severe hype rtension, low renin and aldosterone. and a chronic hypokalemic alkalos is at age 4. The analysis of cortisone, cortisol and their metabolites showed the specific pattern of the apparent mineralocorticoid excess. In serum and urine, there was a dramatic decrease of cortisone and it s metabolite, while cortisol and its metabolites were non affected.