Most participants (n = 56) had familial CRC, some (n = 18) had a confirmed or suspected genetic diagnosis (Lynch Syndrome, FAP/aFAP, Li-Fraumeni/TP53, MAP/MUTYH, PALB2) and a few (n = 8) had other cancer diagnoses (endometrial, breast, pancreatic, thyroid) and a family history of CRC. This evidence concerns the gene FAP and Lynch syndrome.