GCK and diabetes mellitus: Because spontaneous pathogenic variants in some MODY genes can lead to insulin requiring diabetes and can be easily misdiagnosed for T1D [2], the patient underwent a screening of ABCC8, APPL1, GATA4, GATA6, GCK, HNF1A, HNF1B, HNF4A, INS, KCNJ11, NEUROD1, PDX1 and RFX6 genes by next generation sequencing (NGS).