Association study between CD30 and CD30 ligand genes and type 1 diabetes in the Japanese population.

CD30-CD30 ligand (CD3OL) signal transduction appears to protect against autoimmune diabetes by preventing expansion of autoreactive T cells and suppressing Th1-cytokine response. The purpose of this study was to determine whether CD30 or CD30L genes serve as a novel susceptibility gene for type I diabetes in humans. We screened CD30 and CD30L genes for polymorphisms in Japanese patients with type 1 diabetes and control subjects. Then, association studies were performed between each of the identified polymorphisms and type 1 diabetes. Direct-sequencing analysis of the CD30 and CD30L genes revealed four polymorphisms: one in the CD30 gene (-201G/A from the transcription start site), and three in the CD30L gene [CA repeat in the promoter, 276G/A in the exon 3, -73T/C in the intron 3 (IVS3 -73T/C)]. Association studies revealed no association between the CD30 and CD30L genes and type 1 diabetes in the whole population. In the female and male subpopulations, however, the frequency of (CA)[sub 9] allele of the CD30L gene promoter or T allele of IVS3-73T/C polymorphism in the CD30L gene was slightly higher in female patients with type 1 diabetes than that in control females. In conclusion, we could not find significant association between CD30 or CD30L genes and type I diabetes, but (CA)[sub 9] allele in the promotor or T allele of -73T/C in intron 3 in CD30L gene might play a minor role in the pathogenesis of type I diabetes, only in the Japanese female population. [ABSTRACT FROM AUTHOR]