The influence of HLA-DRB1, -DQB1 genes on age at onset of type 1 diabetes in Iranian T1D patients

Survey of the influence of HLA-DRB1, -DQB1 alleles, genotypes and haplotypes on age at onset of type 1 diabetes (T1D) in an Iranian population 105 Iranian T1D patients of different ethnic group and 100 ethnically, age and sex matched individuals were selected from Tehran's hospitals and HLA-DRB, -DQB typing was performed. According to the age at onset of T1D, the patients were divided into 4 groups (1-5, 6-10, 11-15, 16-20 years). The frequency of susceptible and protective alleles, genotypes and haplotypes was calculated in each group. The data were evaluated by using fisher's exact test. Odds Ratio or relative Risk was measured for all samples. The results illustrated that the frequency of the HLA-DRB1*0401 allele decreased with increasing age, whereas the frequency of the HLA-DQB1*0201 allele increased with increasing age. The HLA-DRB1*0301 and HLA-DQB1*0302 alleles demonstrated the highest frequency in the 6-11 and 1-5 years age at onset group, respectively. HLA-DRB1*0401-DQB1*0302 haplotype had the most frequency among the 1-5 years age at onset group (p: 2×10-7, OR: 69.919) and the frequency of HLA-DRB1*0301-DQB1*0201 haplotype was the highest in the 6-11 years age at onset group among others (p: 2×10-6, OR: 6.243). The current study indicated that HLA-DRB1, -DQB1 alleles, genotypes and haplotypes are associated with age at onset of type1 Diabetes in Iranian T1D patients. The individuals carrying alleles that are associated with younger age at onset should take care under preventive treatment.