Additionally, to exclude any cases of monogenic diabetes, children diagnosed with type 1 diabetes at a very young age were excluded and autoantibody-negative children with a first-degree relative affected by type 2 diabetes underwent NGS analysis of 44 genes potentially associated with monogenic diabetes, including seven MODY genes (GCK, HNF1A, HNF1B, HNF4A, INS, ABCC8, KCNJ11). The gene discussed is GCK; the disease is type 1 diabetes mellitus.