Twin and family studies have demonstrated that genetic factors contribute to approximately 50% of the risk for type 1 diabetes [10, 11], with variations in HLA class I (HLA-A, HLA-B, HLA-C) and HLA class II (HLA-DRB1, HLA-DQA1, HLA-DQB1) accounting for 30–50% of the genetic risk [12]. This evidence concerns the gene HLA-DQB1 and type 1 diabetes mellitus.