Comparison of the frequency of polymorphisms of class HLA II genes and the risk of type 1 diabetes mellitus in the indigenous and alien population of the Khanty-Mansiysk autonomous okrug - Yugra

BACKGROUND : In KhMAO-Yugra, every year there is an increase in the number of cases of type 1 diabetes mellitus (DM1) among residents of the district. The preservation of small indigenous peoples is an important demographic problem that requires an integrated approach. HLA-typing makes it possible to identify genetic markers of predisposition to type 1 diabetes mellitus (DM1) in the early stages of the disease and to ensure its prevention. AIM : Identification of the frequency of carriage of polymorphic alleles and haplotypes in the loci of the HLA-DQA1, HLA-DQB1 and HLA-DRB1 genes of the HLA class II system in samples of the indigenous khanty population and the alien population permanently residing in the territory of KhMAO-Yugra. MATERIALS AND METHODS . Low-resolution HLA typing was performed in 60 representatives of the khanty indigenous people, 54 conditionally healthy people of the alien population and 45 patients with type 1 diabetes mellitus (alien population) permanently residing in the territory of the Khanty-Mansiysk Autonomous Okrug. RESULTS : The analysis of the frequency of occurrence of class II HLA alleles in the khanty cohort revealed statistically significant differences in the alleles DQA1*01:02/03; DQB1*02; *03:02; *05:02/04; *06:01; *06:02-8; DRB1*03; *04; *12; *13; *15; *16 in comparison with the cohort of the conditionally healthy alien population. A similar comparison of the frequencies of DQA1, DQB1, DRB1 alleles, haplotypes and their combinations between representatives of the alien population of conditionally healthy and patients with DM1 revealed significant differences in loci DQA1*01:02/03; *03:01; DQB1*06:02-8; DRB1*07, characteristic of Caucasians. When comparing the frequencies of haplotypes in Hunts with a cohort of conditionally healthy newcomers, a statistically significant low frequency of haplotypes associated with a high and moderate risk of developing DM1 (DR4~DQ8, DR3~DQ2) and a high frequency of «protective» haplotypes DQ6~DR15, DQ6~DR13 were noted. CONCLUSION : In the khanty cohort, the frequency of occurrence of three haplotypes predisposing to the development of DM1 was reduced, and two protective haplotypes were increased, in comparison with the cohort of a conditionally healthy alien population. This determines the significant role of genetic factors in the observed low predisposition to the development of type 1 diabetes in the khanty population.