A laboratory evaluation revealed normal levels of sodium (142 mEq/L; reference range (RR): 136–145 mEq/L) and hypokalemia (3.3 mEq/L; RR: 3.5–5.1 mEq/L) despite the intake of over 4 g of potassium per day, undetectable plasma renin activity (PRA <0.2 ng/mL/h, RR: 0.2–2.8 ng/mL/h), and inappropriately high plasma aldosterone concentration (PAC) for PRA (PAC: 14.2 ng/dL, RR: 2.5–31.5 ng/dL). The gene discussed is S100A6; the disease is Hypokalemia.