A Novel Phenotype Of Familial Hyperaldosteronism Type Iii: Concurrence Of Aldosteronism And Cushing'S Syndrome

Context: To date, all the familial hyperaldosteronism type III (FH-III) patients reported presenting with typical primary aldosteronism (PA), without showing other adrenal hormone abnormalities.Objective: This study characterized a novel phenotype of FH-III and explored the possible pathogenesis.Patients and Methods: A male patient presented with severe hypertension and hypokalemi a at the age of 2 years and developed Cushing's syndrome at 20 years. He was diagnosed with PA and Cushing's syndrome on the basis of typical biochemical findings. He had massive bilateral adrenal hyperplasia and underwent left adrenalectomy. KCNJ5 was sequenced, and secretion of aldosterone and cortisol were observed both in vivo and in vitro.Results: A heterozygous germline p.Glu145GIn mutation of KCNJ5 was identified. ARMC5, PRKAR1A, PDE8B, PDE1 1A, and PRKACA genes and beta-catenin, P53 immunoactivity were normal in the adrenal. CYP11 B2 was highly expressed, whereas mRNA expression of CYP11 B1, CYP17A1, and STAR was relatively low in the hyperplastic adrenal, compared with normal adrenal cortex and other adrenal diseases. In the primary cell culture of the resected hyperplastic adrenal, verapamil and nifedipine, two calcium channel blockers, markedly inhibited the secretion of both aldosterone and cortisol and the mRNA expression of CYP1 1 B1, CYP1 1 B2, CYP17A1, and STAR.Conclusions:We presented the first FH-111 pati ent who had both severe PA and Cushing's syndrome. Hypersecretion of cortisol might be ascribed to overly large size of the hyperplastic adrenal because CYP11B1 expression was relatively low in his adrenal. Like aldosterone, synthesis and secretion of cortisol in the mutant adrenal may be mediated by voltage-gated Ca2+ channels.