A diagnosis of EAS is established when patients exhibit clinical manifestations indicative of excessive corticosteroid production and fulfil at least two of the following criteria: spontaneous hypokalemia (potassium of < 3.2 mmol/L), elevated plasma cortisol level (> 660 nmol/L) lacking diurnal variation and/or unresponsive to dexamethasone suppression, elevated plasma ACTH level (> 22 pmol/L), and/or increased 24-hour urinary free cortisol level (> 400 nmol/day). The gene discussed is POMC; the disease is Hypokalemia.