Identification of an ABCC8 variant in a kindred with transient diazoxide responsive hyperinsulinism

The most common genetic cause of hyperinsulinism is gain-of-function variants in ABCC8 and KCNJ11, which make up the ATP-sensitive potassium channel (KATP). First-degree relatives of affected individuals should be considered for genetic testing. Parent-of-origin testing should be done to determine if the patient is likely to have focal or diffuse hyperinsulinism. Diazoxide is helpful for many patients with diffuse hyperinsulinism, and some patients with focal hyperinsulinism.