The standard primary genetic panel for hyperinsulinism at our clinic includes the following genes: ABCC8, GCK, GLUD1, HADH, HK1, HNF1A, HNF4A, INSR, KCNJ11, PMM2, SLC16A1, UCP2 (since 2015 also KDM6A and KMT2D). The gene discussed is HNF4A; the disease is hyperinsulinism.