The most common cause for CHI are mutations in the genes ABCC8 and KCNJ11 (both autosomal recessive and dominant) that encode the SUR1 and Kir6.2 subunits of the pancreatic β-cell KATP channel, respectively (9,10,11,12,13,14). Here, KCNJ11 is linked to congenital isolated hyperinsulinism.