Nature of genomic instability | Example gene mutations | Syndrome associated with germline mutation | Comments |
---|---|---|---|
Chromosomal instability | Loss of function mutation of APC gene | Familial adenomatous polyposis | Somatic APC mutation found in 85% of sporadic CRC4 |
Microsatellite instability | Mismatch repair genes MLH1, MSH2, MSH6 and PMS2 | Lynch syndrome | Somatic inactivation of mismatch repair genes found in 15% sporadic CRC3 |
DNA base excision repair defect | MYH gene | MYH-associated polyposis | No recognised somatic equivalent |