Genetic Testing for Primary Aldosteronism in SPAIN: Results From the SPAIN-ALDO Registry and Review of the Literature

Context: It is estimated that about 5% of the primary aldosteronism (PA) cases are of hereditary origin (familial hyperaldosteronism, FH). To date, 4 forms of FH have been reported. However, in general little is known about the genetic causes that lead to the development of PA. Objective: This work aimed to determine the rate of genetic testing for FH in the SPAIN-ALDO Registry and to describe the clinical characteristics of patients with FH. In addition, a literature review of reports of FH cases was performed. Methods: A retrospective multicenter study of PA in patients followed in 35 Spanish tertiary hospitals (SPAIN-ALDO Registry). Results: Twenty-five of the 855 patients (3%) with PA included in the registry underwent genetic testing for FH, with complete results available for only 24 patients. However, we found that there were 57 patients who met the criteria for performing a genetic study of PA. Only 8 out of these 57 patients were genetically tested (14.0%), while the reasons to perform a genetic study in the remaining 17 genetically studied cases were quite heterogeneous. A positive result for FH was found in only one case for FH type III (KCNJ5 pathogenic variant). A systematic review of the literature was performed and identified a total of 25 articles reporting 246 patients with FH type I, 12 articles reporting 72 patients with FH type II, 14 articles reporting 29 cases of FH type III, and 3 articles reporting 12 patients with FH type IV. Conclusion: The genetic study of FH is often scarce in real-world clinical practice, as 86% of patients with criteria to undergo genetic study were not evaluated in our cohort. Nevertheless, FH is an uncommon cause of PA, representing only 0.2% of cases in the SPAIN-ALDO Registry, although its prevalence may be as high as 4% among suspected cases.