HLA-DQB1 genotyping for four alleles in the assessment of insulin dependent diabetes mellitus risk in the Latvian population

It is well known that the HLA-DQ region contains the markers of both high risk and protective alleles, which reflects the important role of the HLA-DQ region in insulin-dependent diabetes mellitus pathogenesis. The aim of the investigation was to determine the frequency of DQB1 gene alleles spreading and evaluation of the degree of risk among the IDDM patients and healthy inhabitants of Latvia. Our analysis is based on the technique of revealing four alleles of the HLA-DQB1 gene: two alleles associated with the predisposition towards the development of IDDM (DQB1*0201, *0302) and two protective alleles DQB1*0301, *0602/0603). The results of the investigation have shown that in the latvian population the bearers of the DQB1*0302 allele have a strong predisposition to the development of the disease (relative risk, RR = 20.63), but the DQB *0201 allele is associated with a weak predisposition to the development of IDDM (RR = 4.75). Just as the presence in the Latvians' genotype of the DQB1 *0602/0603 allele is associated with strong protection against IDDM (RR = 0.02), the DQB1 *0301 allele is associated with weak protection towards the development of the disease (RR = 0.22).