Epigenetic reduction of DNA repair in progression to gastrointestinal cancer

Table 1 Inherited mutations in DNA repair genes that increase the risk of gastrointestinal cancer

DNA repair gene(s)	Repair pathway(s) affected	Cancers with increased risk
BLM	HRR[1]	Leukemia, lymphoma, colon, breast, skin, lung, auditory canal, tongue, esophagus, stomach, tonsil, larynx, uterus[2]
WRN	HRR, NHEJ, long patch BER[3]	Soft tissue sarcoma, colorectal, skin, thyroid, pancreatic[4]
Fanconi's anemia genes FANCA, B, C, D1, D2, E, F, G, I, J, L, M, N	HRR and TLS[5]	Leukemia, liver tumors, solid tumors in many areas including esophagus, stomach and colon[6]
MSH2, MSH6, MLH1, PMS2	MMR[7]	Colorectal, endometrial[7]
MUTYH	BER of A mispaired with 8-OHdG[8]	Colon[8]
P53	HRR, BER, NER, NHEJ, MMR[9]	Sarcoma, breast, osteo-sarcoma, brain, adreno-cortical carcinomas[10] and colon and pancreas[11]

HRR: Homologous recombinational repair; NHEJ: Non-homologous end joining; BER: Base excision repair; TLS: Translesion synthesis; MMR: Mismatch repair; DDR: DNA damage response.