CHI within the neonatal period and evolution to diabetes later in life has been reported in individuals with heterozygous inactivating mutations in the hepatocyte nuclear factor 4A and 1A genes (HNF4A and HNF1A) (12,13,14) and dominant mutations in ABCC8 genes in a very limited number of cases (1,7,11,13,15,16,17,18,19,20,21). This evidence concerns the gene HNF1A and diabetes mellitus.