Evaluation of high-risk type 1 diabetes HLA-DR and DQ haplotypes using three single nucleotide polymorphisms in a population from Southern Brazil

Background Type 1 diabetes mellitus (T1D) accounts for ~10% of all diabetes cases, and it is caused by autoimmune destruction of pancreatic beta-cells, which leads to insulin deficiency and fates individuals to require insulin treatment to survive. The triggering of autoimmunity against betacells is caused by interaction between environmental and genetic risk factors. Among the several loci associated with T1D, the human leukocyte antigen (HLA) class II DR/DQ locus is the main genetic risk factor for T1D, accounting for 30-50% of genetic risk for this disease. Other genes have been associated with minor effects on T1D risk when compared with HLA, with different studies indicating that the effect of non-HLA polymorphisms on predisposition for T1D may be different according to HLA DR/DQ types. In this scenario, a recent study identified a minimum set of three polymorphisms (rs3104413, rs2854275, rs9273363) which can predict high-risk HLA-DR/DQ types relevant to T1D.