According to the recommendations of the European Society of Hypertension [8], as the specificity for PA diagnosis increases with ARR value [19], a patient with spontaneous hypokalemia, plasma aldosterone greater than 20 ng/dL (550 pmol/L), and renin (PRA or DRC) below detection limit is considered to possess PA without needing a confirmatory test. This evidence concerns the gene REN and Hypokalemia.