MODY is the most common type of monogenic diabetes, with autosomal dominant inheritance and caused by pathogenic variants resulting in pancreatic beta cell dysfunction, such as HNF4A, GCK, HNF1A, PDX1, HNF1B, NEUROD1, KLF11, CEL, PAX4, INS, BLK, ABCC8, KCNJ11, APPL1. Here, HNF1A is linked to diabetes mellitus.