The molecular basis of CHI involves defects in key genes (ABCC8, KCNJ11, GLUD1, GCK, HADH, SLC16A1, HNF1A, HNF4A, UCP2, HK1, PGM1, PMM2 and FOXA2) which regulate insulin secretion. This evidence concerns the gene HNF4A and congenital isolated hyperinsulinism.