Genomic and functional analyses of MUTYH in Japanese patients with adenomatous polyposis
Genomic and functional analyses of MUTYH in Japanese patients with adenomatous polyposis
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DOI：
10.1111/j.1399-0004.2008.00998.x
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发表时间：
2008-06-01
影响因子：
3.5
通讯作者：
Iida, M.
中科院分区：
文献类型：
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作者：
Yanaru-Fujisawa, R.;Matsumoto, T.;Iida, M.
本研究旨在阐明日本腺瘤性息肉病患者中碱基切除修复基因MUTYH的种系突变。我们筛选了66例日本腺瘤性息肉病患者的大肠腺瘤性息肉病（APC）基因和MUTYH的种系突变。APC采用蛋白截断法筛选，MUTYH采用基于聚合酶链反应的单链构象多态性和直接测序法筛选。采用切口法评价鉴定的MUTYH变异的DNA糖基酶活性。在这项研究中，21例apc阴性患者中有16例发现了7种MUTYH变异。Q324H突变是最常见的突变，等位基因频率为49%。2例患者携带Q324H以外的双等位基因突变；1例患者为G272E和A359V双等位基因突变，1例患者为P18L和G25D复合杂合子突变。使用G257E对应的小鼠MUTYH突变体对G272E进行刻蚀试验显示，G272E是一种导致DNA糖基酶活性受损的变体。纯合子MUTYH突变约占日本腺瘤性息肉病患者的10%。G272E可能是东亚腺瘤性息肉病患者特有的突变之一。
The present study was undertaken to elucidate germ line mutations of the base excision repair gene, MUTYH, in Japanese patients with adenomatous polyposis. We screened germ line mutations of adenomatous polyposis coli (APC) gene and MUTYH in 66 Japanese patients with adenomatous polyposis. APC was screened by the protein truncation test, while MUTYH was screened by polymerase chain reaction-based single-strand conformation polymorphism and direct sequencing. The nicking assay was applied in order to evaluate the DNA glycosylase activity of the identified MUTYH variant. In this study, Seven MUTYH variants were identified in 16 of 21 APC-negative patients. Q324H mutation was the most frequent mutation, with an allele frequency of 49%. Two patients carried biallelic mutations other than Q324H; a patient had biallelic G272E and A359V mutations, while the other had compound heterozygotes of P18L and G25D mutations. Nicking assay for G272E using the corresponding mouse MUTYH mutant with G257E revealed that G272E is a variant to cause an impaired DNA glycosylase activity. Homozygous MUTYH mutation accounts for approximately 10% of Japanese patients with adenomatous polyposis. G272E may be one of the mutations specific to patients with adenomatous polyposis in East Asia.