Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete potassium in urine (potassium adaptation), while it becomes common in patients with chronic kidney disease (CKD), mainly due to the reduction of renal function, metabolic acidosis, and the wide use of renin-angiotensin system inhibitors (RASI) [4]. This evidence concerns the gene REN and chronic kidney disease.