Primary hyperaldosteronism (PAH) is the most frequent cause of secondary arterial hypertension. Most PAHs occur sporadically, but 5% of cases have a hereditary origin (familial PAH). Four forms of familial PAH have been described. Type I familial PAH is produced by a fusion of the CYP11B2 and CYP11B1 genes, in this way the synthesis of aldosterone becomes to be regulated by ACTH instead of by angiotensin II. In type II, III and IV familial PAH there is an increase in the transcription and expression of CYP11B2 responsible for aldosterone synthesis due to a germinal mutation in CLCN2, KCNJ5 and CACNA1H, respectively. On the other hand, somatic mutations have been identified in 50% of sporadic PAHs, with gain-of-function mutations at the level of KCNJ5, ATP1A1, ATP2B3 and CACNA1D being the most common. This review provides a detailed description of the different forms of familial PAH and the molecular profile of patients with sporadic PAH.
