Patient with HNPCC (hereditary nonpolyposis colon cancer) has genes with microsatellite instability. This is due to failure of which repair mechanism of DNA
Mismatch repair
Base excision repair
Homologous end joining repair
Non homologous end joining repair
Mismatch repair: It is one of the repair mechanisms in DNA replication. It operates when there is mismatched base paining. For eg: when A pairs with C. This repair mechanism is defective in HNPCC.