Using DNA isolated from blood taken from patients (<i>n</i> = 312) and a control group (<i>n</i> = 320) with CRC, we have analyzed the polymorphisms of selected DNA repair genes and we have demonstrated that genotypes 51Gln/His and 148Asp/Glu of APEX gene and 23Gly/Ala of XPA gene may increase the risk of colorectal cancer.
The MUTYH Gln324His is strongly associated with colorectal cancer</span> susceptibility in never smoking history, whereas the APEX1 Asp148Glu genotype constitutes an increased risk of colorectal cancer when accompanied by smoking exposure.