High Throughput Genetic Screening for the Detection of Hereditary Nonpolyposis Colon Cancer (HNPCC) Using Capillary Electrophoresis

摘要

Approximately 5-10% of all colorectal carcinomas arise from cancer predisposition syndromesncaused by heterozygote germline mutations in post-replicative DNA mismatch repair (MMR) genes. Inncontrast to gastrointestinal polyposis syndromes, carcinomas in these patients do not occur on thenbackground of increased numbers of polyps and hence are refered to as hereditary non-polyposis colorectalncancers (HNPCC). Six different MMR genes, MSH2, MSH3, MSH6, MLH1, MLH3 and PMS2, havenbeen identified in the human genome. In the majority of HNPCC patients, heterozygote germlinenmutations are present in the MSH2 or MLH1 gene. Detection of mutations by conventional sequencingntechnology is expensive and labor intensive due to the complex intron and/or exon structures. In thisnstudy, we therefore have explored whether capillary electrophoresis-based single strand conformationnpolymorphism (SSCP-CE) provides a reliable means for mutation screening. We have tested differentnMLH1 mutations in exons 9 and 16 and find that SSCP-CE produces reliable electrophoretic patterns thatnallow recognition of wild-type alleles, microdeletions and point mutations. In summary, SSCP-CEnprovides a rapid, automated, and cost-effective technology for MSH2 and MLH1 mutation screening andnwill facilitate genetic diagnostics for HNPCC patients.