Persistent CHI can be caused by mutations in nine genes regulating the insulin secretion from the β-cells (ABCC8, KCNJ11, GLUD1, HADH, GCK, HNF4A, HNF1A, SLC16A1, and UCP2 genes) (6,7). The gene discussed is INS; the disease is congenital isolated hyperinsulinism.