The molecular basis of CHI involves defects in key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF1A, HNF4A, UCP2, HK1, PGM1 and PMM2) which regulate insulin secretion. Here, GLUD1 is linked to congenital isolated hyperinsulinism.