The two most common syndromes are familial adenomatous polyposis (FAP) and hereditary non-polyposis colon cancer (HNPCC) that arise due to mutations in the APC (Adenomatous polyposis coli) gene and mismatch repair genes (MSH2, MLH1, MSH6 and PMS2), respectively. Here, APC is linked to hereditary nonpolyposis colon cancer.