KCNJ11 and congenital isolated hyperinsulinism: In 50–66% of patients with diffuse CHI, mutations are found in the KATP-channel genes ABCC8 or KCNJ11, coding for the sulphonylurea receptor 1 (SUR1) and the potassium inward rectifier 6.2 (Kir6.2), respectively [6, 8].