Pathogenesis of autoimmune diabetes mellitus is activated by genetic and environmental factors. The most important genetic risk factors are the HLA class II. alleles (DQB1*0302,0201; DRB1*0301,0401; DQA1*0301,0501) and the risk alleles of INS-VNTR of promoter region.
Further there are the genetic polymorphisms in some cytokine genes (IL-10, IL-12, IL-18) and the microsatelite polymorphism of MHC class I chain-related gene A (MIC-A).