Cancer-predisposing germline mutations of APC, MUTYH and mismatch repair genes are already known to be associated with familial CRC and to lead to: phenotypes of well-defined Mendelian CRC syndromes, familial adenomatous polyposis (FAP), resulting from APC gene mutations; MUTYH-associated polyposis (MAP); and Lynch syndrome, a hereditary non-polyposis colon cancer (HNPCC) syndrome caused by mismatch repair gene mutations (MLH1, MSH2, MSH6, PMS2 and EPCAM) [2]. This evidence concerns the gene PMS2 and Familial adenomatous polyposis.