Prevalence of human leukocyte antigen DQA1 and DQB1 alleles in Kuwaiti Arab children with type 1 diabetes mellitus

The prevalence of human leukocyte antigen (HLA) DQB1 and DQA1 alleles has b een determined in 78 Kuwaiti Arab children with insulin-dependent diabetes mellitus (IDDM) and in 57 normal healthy controls with similar ethnic backg round. The typing of HLA-DQ alleles was carried out using an allele-specifi c DNA-based polymerase chain reaction (PCR) SSP method, DR typing was also performed in 212 control subjects using PCR-SSP (sequence specific primer) method. A significantly higher frequency of DQB1*0201 allele was found in I DDM cases compared to the controls (p < 0.001). There was no significant di fference in the prevalence of DQB1 alleles *0302, *0501, and *0602 between IDDM cases and the controls. In contrast, DQB1 alleles *0301, *0402, *0502, *0602, and *0603 were represented at a somewhat higher frequency in contro ls compared to the IDDM cohort. The frequency of DQA1 allele *0301, which e ncode for an Arg at codon 52, was significantly higher in the IDDM patients compared to the controls (p < 0.001), The frequency of DQA1 allele *0302 w as also higher in IDDM cases than controls (p = 0.034) but the difference w as less pronounced than DQA1*0301. Amongst the Arg(52) alleles, no signific ant difference was detected in the frequency of *0401 between IDDM cases an d the controls and the allele *0501 was detected only in controls. For non- Arg(52) alleles *0103, *0104, and *0201, the differences in the two groups were not significant, with the exception of allele *0104 (p = 0.024). DR3 w as the most common type in the Kuwaiti general population (28%) and DRB1*03 01 was detected in 41% of the individuals with DR3 specificity. Analysis of HLA-DQB1/DQA1 haplotypes from IDDM cases and controls revealed a significa ntly high frequency of haplotype DQA1*0301/DQB1*0201 between Kuwaiti IDDM c ases (49/78, 63%) and the controls (8/57, 14%).