Frequent MSI mononucleotide markers for diagnosis of hereditary nonpolyposis colorectal cancer.

BACKGROUND Failure in the DNA mismatch repair system is commonly accompanied by microsatellite instability and leads to colorectal cancer. The aim of this study was to find the most frequent of five mononucleotide markers in order to devise the simplest diagnostic strategy for identification of patients with hereditary nonpolyposis colorectal cancer (HNPCC) who were defined by defects in mismatch repair system. MATERIALS AND METHODS 78 patients with colorectal cancer were recruited for this investigation. Five mononucleotide markers, NR-27, NR-21, NR-24, BAT-25 and BAT-26, were used as a pentaplex panel to determine MSI status. RESULTS Two out of five mononucleotide markers, NR-21 (25.6%) and BAT-25 (23.1%) showed more instability than the others. CONCLUSION In defining individuals with colorectal cancer, BAT25 and NR-21 may provide diagnostic assistance.