Allele variants of HLA II genes DRB1 and DQB1 regarding risk for type 1 diabetes mellitus in population of Bashkortostan

Aims. To estimate significance of HLA II DRB1 and DRB2 allele variants for development of type 1 diabetes mellitus (T1DM) in Bashkortostan population (ethnical Russians, Tatar, Bashkir). Materials and methods. We analyzed DNA of 323 patients with T1DM and 683 healthy controls. DNA was derived from venous blood samples by phenol-chloroform extraction. DRB1 and DQB1 gene typing was performed by PCR method. Amplification products were identified with electrophoresis on a 1% agarose gel. Statistica for Windows v6.0 and MS Excel ' 98 software were applied for statistical processing of acquired data. Results. Common markers of high risk for T1DM were found to be DRB1*04, DRB1*17, genotype DRB1*04/*17. On the contrary, lower risk was associated with DRB1*15 allele. In ethnical Russians lower risk of T1DM is also determined by DRB1*11 allele and DRB1*01 in Tatars. Predisposition by DQB1-alleles in Russians and Bashkir realizes only within DRB1*04/*17 genotype. However, in Tatar subpopulation DQB1*0302 is an independent risk marker of T1DM development. Conclusion. Common low risk markers for all three ethnic groups are DQB1*0301, DQB1*0602-08 alleles. Their presence negates risk of disease in all studied subpopulations even within DRB1*04/*17-genotype.