Prevalence and characteristics of familial hyperaldosteronism: the PATOGEN study (Primary Aldosteronism in TOrino-GENetic forms)

Primary aldosteronism (PA) is the most frequent cause of secondary hypertension, and patients display an increased prevalence of cardiovascular events compared with essential hypertensives. To date, 3 familial forms of PA have been described and termed familial hyperaldosteronism types I, II, and III (FH-I to -III). The aim of this study was to investigate the prevalence and clinical characteristics of the 3 forms of FH in a large population of PA patients. Three-hundred consecutive PA patients diagnosed in our unit were tested by long-PCR of the CYP11B1/CYP11B2 hybrid gene that causes FH-I, and all of the available relatives of PA patients were screened to confirm or exclude PA and, thus, FH-II. Urinary 18-hydroxycortisol and 18-oxocortisol were measured in all of the familial PA patients. Two patients were diagnosed with FH-I (prevalence: 0.66%), as well as 21 of their relatives, and clinical phenotypes of the 2 affected families varied markedly. After exclusion of families who refused testing and those who were not informative, 199 families were investigated, of which 12 were diagnosed with FH-II (6%) and an additional 15 individuals had confirmed PA; clinical and biochemical phenotypes of FH-II families were not significantly different from sporadic PA patients. None of the families displayed a phenotype compatible with FH-III diagnosis. Our study demonstrates that familial forms of hyperaldosteronism are more frequent than previously expected and reinforces the recommendation of the Endocrine Society Guidelines to screen all first-degree hypertensive relatives of PA patients.