A novel MSH2 mutation in a Chinese family with hereditary non-polyposis colorectal cancer.

Background and aims Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common hereditary colon cancer syndrome accounting for 1–5% of all colorectal cancer cases. Germline mutations in DNA mismatch repair (MMR) genes are associated with the clinical phenotype of HNPCC. Defects in the MSH2 gene may account for about 40% of HNPCC cases including nucleotide substitutions, deletions and insertions. Only a few mutations were reported in Chinese families. This study was performed to identify the disease-causing gene mutation(s) and conduct pre-symptomatic diagnosis in a Chinese family with HNPCC.