RFLP Analysis of HLA-DRβ and -DQβ Genes in the Korean Patients with Insulin-Dependent Diabetes Mellitus

Human genomic DNA samples from 19 Korean patients and 31 controls of known serological DR antigen specificity were studied for insulin-dependent diabetes mellitus (IDDM)-associated variation in HLA-DRβ and - DQβ restriction fragment length polymorphisms (RFLPs). Genotyping allowed for accurate assignment of HLA-DR types. For HLA-DRw6, a 12kb/DRβ/Taq I fragment was decreased in Korean IDDM (p<0.05). However, we could not find an increased frequency of a 12kb/DQβ/Bam HI fragment or decreased frequency of a 3.7kb/DQβ/Bam HI fragment in Korean IDDM. These results suggest a possible protective role of the HLA-DRw6 specificity in IDDM, irrespective of ethnic background, the absence of a specific DQβ RFLP pattern associated with IDDM in Koreans, and the difference of the Korean population in the genetic of IDDM, compared to the Caucasoid population.