DNA repair gene XRCC7 G6721T variant and susceptibility to colorectal cancer
Background: The human XRCC7 (MIM: 600899) is a DNA double-strand break repair gene, involved in non-homologous end joining (NHEJ). Polymorphism G6721T (rs7003908) is located in the intron 8 of the XRCC7. This polymorphism may regulate splicing and cause mRNA instability.
Aim: The aim of the present study was to determine an association of G6721T XRCC7 polymorphism in colorectal cancer.
Subjects and methods: The study included 166 patients with colorectal cancer and 260 age and gender frequency-matched controls. The patients and controls were Iranian (Caucasian/Muslims).
Results: Our data did not demonstrate any statistically significant association between the genotypes of XRCC7 G6721T polymorphism and risk of colorectal cancer. There was a significant association between family history of cancers among their first-degree relatives (FH) and risk of colorectal cancer (OR =3.69, 95% CI: 2.19–6.23, P <0.001). We further analyzed to see if the FH influenced the association of the XRCC7 G6721T polymorphism and colorectal cancer risk. The TT genotype among positive FH persons, remarkably increased the risk of colorectal cancer (OR= 6.88, 95% CI: 2.27–20.8, P = 0.001).
Conclusion: The present study suggests the TT genotype of the XRCC7 G6721T polymorphism might be a risk factor for the development of colorectal cancer among persons with positive FH.