Novel single nucleotide polymorphisms of the dihydropyrimidinase gene (DPYS) in Japanese individuals.

Genetic polymorphisms of the dihydropyrimidinase gene (DPYS) may be associated with the development of severe toxicity to 5-fluorouracil, a drug used to treat solid tumors. In this study, we analyzed the nine coding exons and exon-intron junctions of DPYS in 183 Japanese individuals. We detected two novel single nucleotide polymorphisms (SNPs)-285C > T (Thr95Thr) and 349T > C (Trp117Arg)-in exon 2. The nonsynonymous SNP 349T > C was analyzed in 208 Japanese individuals. Although the allele frequency of the SNP in the Japanese population was found to be extremely low (0.13%), the enzymatic activity of the variant protein might be reduced compared with that of the wild-type protein.