DPYD（dihydropyrimidine dehydrogenase），癌症关联基因，基因ID：1806，该基因编码的蛋白是嘧啶分解代谢酶，是尿嘧啶和胸腺嘧啶分解代谢途径的起始和限速因子。该基因突变导致二氢嘧啶脱氢酶缺乏，嘧啶代谢错误与胸腺嘧啶尿嘧啶尿有关，癌症患者接受5-氟尿嘧啶化疗后毒性增加。两个编码不同亚型的转录变体已经被发现。The protein encoded by this gene is a pyrimidine catabolic enzyme and the initial and rate-limiting factor in the pathway of uracil and thymidine catabolism. Mutations in this gene result in dihydropyrimidine dehydrogenase deficiency， an error in pyrimidine metabolism associated with thymine-uraciluria and an increased risk of toxicity in cancer patients receiving 5-fluorouracil chemotherapy. Two transcript variants encoding different isoforms have been found for this gene.关联癌症：癌症。关联化疗药物：卡培他滨。