SEVERAL HOMOZYGOUS MUTATIONS IN THE GENE FOR 11-BETA-HYDROXYSTEROID DEHYDROGENASE TYPE-2 IN PATIENTS WITH APPARENT MINERALOCORTICOID EXCESS

Four deleterious mutations are described in the gene for HSD11B2, whic h encodes the type 2 isoenzyme of 11 beta-hydroxysteroid dehydrogenase (11 beta HSD2). In seven families with one or more members affected b y apparent mineralocorticoid excess, this disorder is shown to be the result of a deficiency in 11 beta HSD2. Surprisingly, the patients are all homozygous for their mutation. This results from consanguinity in two families and possibly from endogamy or a founder effect in four o f the other five families. The absence of compound heterozygotes remai ns to be investigated.