Association of HLA-DQ trans-heterodimers with prevalence of type 1 diabetes mellitus in Buryat ethnic group

Aims. Search for the most pronounced HLA II markers of type 1 diabetes mellitus (T1DM) in Buryat ethnic group and analysis ofHLA-DQ trans-heterodimers. Materials and methods. Case control design was applied for assessment of 74 patients with T1DM and 61 healthy individuals. Alleleidentification was performed with multi-primer allele-specific PCR technique. Association of genetic markers with pathology wasevaluated according to odds ratio (OR) index. All calculations were performed with StatSoft and STATISTICA 6 software applications. Results. We show that regarding race-specific highly diabetogenic HLA class II haplotypes Buryat ethnic group holds intermediateposition between Mongoloids and Caucasians and none of those haplotypes are associated with T1DM. We revealed a statisticallysignificant association of T1DM with DQA1*0301+DQB1*0201+ phenotype represented by trans-coding alleles in 77% of cases. Onpopulation level DQA1*0301+DQB1*0302+ or *0201+ phenotype is found to be the most sensitive marker. It was registered in 43%of patients with T1DM against 11.5% of controls (OR 5.9; рс=0.0094). DQA1*0301+/DQВ1*0201 and DQВ1*0302 phenotype is themost specific marker, registered in 16% of patients, but not found in controls (OR 11.8; рс=0.047).Conclusions. HLA-mediated risk for development of T1DM in Buryat ethnic group is determined by HLA-DQ trans-heterodimers.