At present, there are 14 types of MODY genes reported in the online human Mendelian genetic database, namely MODY1/HNF4α,MODY2/GCK,MODY3/HNF1α,MODY4/PDX1,MODY5/HNF-1β,MODY6/NEUROD1,MODY7/KLF11,MODY8/CEL,MODY9/PAX4,MODY10/INS,MODY11/BLK,MODY12/ABCC8,MODY13/KCNJ11,MODY14/APPL1.[11–13] All currently known subtypes of MODY are caused by dominantly acting heterozygous mutations in genes important for the development or function of β-cells. This evidence concerns the gene HNF1B and MODY.