DNA sequence analysis of HLA-DQB genes associated with insulin-dependent diabetes mellitus in Japanese
Takahashi, H.; Katagiri, M.
Hokkaido Journal of Medical Science 65(4): 412-418
1990
ISSN/ISBN: 0367-6102 PMID: 2227793 Document Number: 365715
Recently it has been reported that 57th amino acid of DQ beta antigen was a non-aspartic acid in the most Caucasian patients with insulin-dependent diabetes mellitus (IDDM). Using serological analysis, HLA-DQ antigens show a strong association with IDDM rather than the HLA-DR antigens. In the Caucasian population, IDDM is associated with DQw2 and DQw3 antigens. However, in the Japanese population, DQw4 and DQw9 antigens are strongly associated with IDDM. In order to determine the possible significance of the 57th amino acid of DQ beta chain for the susceptibility to IDDM in Japanese, we performed DNA Sequence analysis of HLA-DQB from Japanese IDDM patient, its same HLA genotyped healthy sibling and B cell line with Japanese IDDM associated haplotype. The results revealed that all of the 57th amino acid are aspartic acid which is thought to contribute to develop IDDM resistance in Caucasian. Furthermore we could not find any other amino acid sequence of DQ beta chain which might contribute to the susceptibility of the Japanese IDDM.