Department of Pathology, Shanghai Cancer Center, Fudan University, Shanghai 200032, China.
World J Gastroenterol. 2010 Aug 14;16(30):3847-52. doi: 10.3748/wjg.v16.i30.3847.
To study the germline mutation of hPMS2 gene in 26 unrelated Chinese hereditary nonpolyposis colorectal cancer (HNPCC) probands and to fulfill the screening strategy for HNPCC in Chinese.
Genomic DNA was extracted from the peripheral blood. To avoid the interference of pseudogene in detection of the remaining 11 exons (exon 1-5, 9, 11-15), long-range polymerase chain reaction (PCR) was conducted to amplify the complete coding region of hPMS2 gene firstly. Then 1/8 of the PCR products were used as template to amplify the individual exon respectively and DNA sequencing was done. Direct DNA sequencing of the conventional PCR products of exon 6, 7, 8 and 10 of hPMS2 gene was performed. The same analysis was made in 130 healthy persons without family histories of HNPCC to further investigate the pathological effects of the detected missense mutation.
One HNPCC proband fulfilled Bethesda guidelines and was found to carry the germline mutation of hPMS2 gene, which has not been reported in Chinese HNPCC families. It was a missense mutation at c.1532C>T of exon 11. It was detected in three controls as well with an occurrence rate of 2.3% (3/130). Since it could not be found in the PMS2-single nucleotide polymorphism (SNP) database, this missense mutation is a new SNP unreported up to date. Meanwhile, 260 reported SNPs of hPMS2 gene were detected in the 26 HNPCC probands. The 2nd and 5th exons were probably the hot SNP regions of hPMS2 gene in Chinese HNPCC families involving 53.1% of all reported SNP.
The germline mutation of hPMS2 gene may be rare in Chinese HNPCC families. The 2nd and 5th exons are hot SNP regions of hPMS2 gene.
研究 26 个无亲缘关系的中国遗传性非息肉病结直肠癌（HNPCC）先证者的 hPMS2 基因胚系突变，并为中国 HNPCC 人群制定筛查策略。
提取外周血基因组 DNA。为避免在检测其余 11 个外显子（外显子 1-5、9、11-15）时假基因的干扰，首先进行长距离聚合酶链反应（PCR）扩增 hPMS2 基因的完整编码区。然后，以 1/8 的 PCR 产物为模板分别扩增各外显子，进行 DNA 测序。对 hPMS2 基因外显子 6、7、8 和 10 的常规 PCR 产物进行直接 DNA 测序。对 130 名无 HNPCC 家族史的健康人进行相同的分析，以进一步研究所检测的错义突变的病理效应。
1 例 HNPCC 先证者符合贝塞斯达指南，携带 hPMS2 基因胚系突变，该突变在中国 HNPCC 家族中尚未报道。这是外显子 11 的 c.1532C>T 错义突变。在 3 名对照者中也发现了这种突变，发生率为 2.3%（3/130）。由于它在 PMS2-单核苷酸多态性（SNP）数据库中无法找到，因此这种错义突变是一种新的尚未报道的 SNP。同时，在 26 例 HNPCC 先证者中检测到 260 个 hPMS2 基因报道的 SNP。第 2 外显子和第 5 外显子可能是中国 HNPCC 家族中 hPMS2 基因的热点 SNP 区域，涉及所有报道 SNP 的 53.1%。
hPMS2 基因的胚系突变在中国 HNPCC 家族中可能较为罕见。第 2 外显子和第 5 外显子是 hPMS2 基因的热点 SNP 区域。
