Study on the association of HLA-DR4 with IDDM susceptibility in a Chinese population]

HLA-DR4 and its subtypes were studied by PCP/SSP, PCR/SSOP, and PCR/RFLP methods in 81 patients with IDDM and 106 normal controls in the Han's nationality Chinese population. The results showed no difference in frequencies of DR4 between the IDDM group and the controls (21.0% vs 17.9%), but DRB1*0405, as a subtype Dw15, was significantly associated with IDDM susceptibility (58.8% vs 21.1%, RR = 2.67, P < 0.05). In a family with 2 IDDM patients, it has been found the haplotype DRB1*0405-DQB1*0302 was to be cosegregated with IDDM. It was suggested that DW15 subtype might be associated with IDDM in Chinese because of linkage disequilibrium with DQw8 (DQB1*0302). As an additional evidence, the findings above mentioned may account for the different association of different DR4 subtypes with IDDM in various ethnic groups.