After identification of a high aldosterone/renin ratio, confirmatory tests (saline infusion test or captopril test) may follow the screening assays, but not necessarily, unless spontaneous or diuretic-induced severe hypokalaemia or highly suggestive plasma aldosterone levels with suppressed renin values are presented and highly suggestive for the diagnostic [83,84,85,86]. The gene discussed is REN; the disease is Hypokalemia.