Hyperinsulinism.

A 2-year-old boy had had severe intractable hypoglycaemia since birth. Transient success with diazoxide treatment delayed diagnosis until the age of 1 1/2 years. It was based on measurements of plasma insulin, blood glucose and urinary ketones at the end of a controlled fast, a normal glycaemic response to glucagon and an unusually high rate of glucose infusion necessary to maintain the blood sugar at a normal level. Subtotal pancreatectomy restored the blood sugar to normal without any impairment of exocrine pancreatic function.