Germ-line Mutations In The HMLH1and HMSH2Gene In The Chinese Colorectal Cancer(CRC) Patients:a Systematic Analysis

AIM:To eveluate the germline mutations in the human MutL Homolog1(hMLH1) and human MutS Homolog2(hMSH2) genes in colorectal cancer (CRC) of Chinese patients.METHOD:Systematic computererized searches of the PubMed and Medline datebases(up to Nov,2011), papers meeting inclusive and exiclusive criterias were made into further analysis. The total results of15releted studies were put into analyzing by Meta-analysis method in this study. The Review Manager4.2software was used to explore the prevalence and95%confidence intervals (CI).RESULTS:The mutation rate of germline mutations in the hMLHl and hMSH2genes in CRC of Chinese patients was0.14(95%CI:0.08-0.24) and0.10(95%CI:0.06-0.17), respectively. The subgroup analysis found prevalences both in the hMLHl and hMSH2gene in the HNPCC group,with a mutation rate of0.35(12=0%, fixed model,95%CI:0.28-0.43),0.14(12=46.1%, fixed model,95%CI:0.09-0.21) respectively, were significantly higher than either atypical HNPCC group or the Sporic CRC group (P <0.01).Missense mutation as the most common mutation typical still needs further research.Frameshift,nonsense(stop) mutation,or aberrant splicing has also been reported a lot,While there is only two cases of silent mutation found in hMSH2gene. hMLH1has higher incidence of mutation in10th-12th Exons and16th Exons. hMSH2 has higher mutatio incidence in7th Exon.CONCLUSION:The systemic review showed germline mutations in the hMLH1and hMSH2genes play an important role in Chinese CRC patient.A higher prevalence was found in HNPCC patients under ACI/Ⅱ criteria.Missense mutation is the most common mutation type in Chinese people.