TDG（thymine DNA glycosylase），癌症关联基因，基因ID：6996，该基因编码的蛋白属于TDG/mug DNA糖基化酶家族胸腺嘧啶DNA糖基化酶（TDG）通过水解DNA糖磷酸骨架与错配胸腺嘧啶之间的碳氮键，从G/T错配中去除胸腺嘧啶部分由于活性较低，这种酶也能去除c/t和t/t错配的胸腺嘧啶。tdg还可以去除尿嘧啶和5-溴脲醛与鸟嘌呤的错配。这种酶在细胞防御5-甲基胞嘧啶和胞嘧啶自发脱氨引起的基因突变中起着中心作用。这个基因可能在12号染色体的p臂上有一个假基因。[由RefSeq提供，2008年7月]The protein encoded by this gene belongs to the TDG/mug DNA glycosylase family. Thymine-DNA glycosylase (TDG) removes thymine moieties from G/T mismatches by hydrolyzing the carbon-nitrogen bond between the sugar-phosphate backbone of DNA and the mispaired thymine. With lower activity， this enzyme also removes thymine from C/T and T/T mispairings. TDG can also remove uracil and 5-bromouracil from mispairings with guanine. This enzyme plays a central role in cellular defense against genetic mutation caused by the spontaneous deamination of 5-methylcytosine and cytosine. This gene may have a pseudogene in the p arm of chromosome 12. [provided by RefSeq， Jul 2008]。