This includes insulin‐mediated causes of hypoglycaemia such as exogenous sulphonylurea or insulin administration, insulin or insulin receptor antibodies, renal failure and post‐gastric bypass syndrome, and non‐insulin mediated causes like hepatic failure, malnutrition, adrenal insufficiency, and insulin‐like growth factor secreting tumours. The gene discussed is INS; the disease is Hypoglycemia.