Frequent Microsatellite Instability and Mismatch Repair Gene Mutations in Young Chinese Patients With Colorectal Cancer

摘要: Background: The incidence of colorectal cancer in persons under 46 years age is substantially higher Hong Kong than Scotland and many other countries. Consequently, we examined whether there a hereditary predisposition for this Southern Chinese population. Methods: We investigated the microsatellite instability (MSI) at 10 DNA sites 117 specimens from patients various ages. Those tumors with new alleles 40% or more were identified as highly unstable MSI (MSI-H). In young patients, also searched germline mutations three mismatch repair genes (hMSH2, hMLH1, hMSH6). Results: MSI-H varied statistically significantly age, being observed 60% those younger 31 diagnosis fewer 15% older. 15 (<46 old) whose cancers showed MSI-H, eight possessed either hMSH2 hMLH1. When hMSH6 included, 80% had genes. found novel missense mutation 29-year-old man tumor no MSI. Two 4-base-pair insertion exon causing truncated protein; common polymorphism population allele frequency 5.6%. Conclusions: Our results indicate that contribute to pathogenesis high Chinese. However, because Caucasians show similar proportions despite former, additional factors may underlie susceptibility cancer. [J Natl Cancer Inst 1999;91: