Mutations in 11 genes, including ABCC8, KCNJ11, GLUD1, GCK, HADH, UCP2, SLC16A1 (MCT1), HNF4A, HNF1A (6), HK1 (7), and PGM1 (8) are known to cause CHI. Here, HNF4A is linked to congenital isolated hyperinsulinism.