HLA-DQB1-ASTERISK-0304-DRB1-ASTERISK-0408 HAPLOTYPE ASSOCIATED WITH INSULIN-DEPENDENT DIABETES-MELLITUS IN POPULATIONS IN THE EASTERN BALTIC REGION

The rare HLA-DQB10304 allele was found increased among IDDM patients in the populations of the eastern Baltic region. Its frequency among I DDM patients was 4.5% (20/443) compared to 1.1% (9/853) in healthy con trols in the combined series of Estonian, Latvian and St. Petersburg R ussian populations (P=0.0001). HLA-DQB10304 in these populations was associated with DRB10408, and the haplotype was further characterized by a B35 allele and a typical combination of microsatellite markers f rom the TNF gene region. The result is compatible with the significanc e of the 57th amino acid in the DQ beta-chain but also emphasizes the importance of alleles in other HLA loci adjacent to DQ in the determin ation of IDDM susceptibility.