Polymorphisms of the DNA repair gene XPD (751) and XRCC1 (399) correlates with risk of hematological malignancies in Turkish population

Polymorphisms that occur in DNA repair genes affect DNA repair capacity and constitute a risk factor in hematological malignancies. This study, was aimed to investigate whether xeroderma pigmentosum complementation group D (XPD) and x-ray repair cross-complementing group 1 (XRCC1) gene polymorphisms were involved in the susceptibility to different hematological malignancies. The genotype and allele frequencies were obtained by analyzing XPD gene codon 751 in a total of 80 patients and XRCC1 gene codon 399 polymorphism in a total of 100 patients with hematological malignancies and 100 healthy controls. Mean age was 45 (range: 16 to 75) and 46 (range: 16 to 82) in the patients groups and 39.5 (range: 18 to 67) in the control group, respectively. Additionally, distribution of genotypes and alleles were compared in the patient and control groups. In the comparison of genotype and allele frequencies in hematological malignancies and healthy controls, XPD-751Gln variant was arranged and compared according to age and sex and Gln/Gln genotype was reported to be a protector, which was decreased significantly in acute myeloblastic leukemia (AML) (p = 0.042). No relationship was determined between allele frequencies (p = 0.054). In XRCC1-399, it was shown that Gln/Gln genotype was decreased significantly in AML (p = 0.014) plus all hematological malignancies (p = 0.033) and that Gln allele was present at a lower ratio in AML (p = 0.046). The distribution of polymorphism of both genes was not statistically significant in terms of age and sex. In leukemia with early relapse, XPD 751 Lys/Lys genotype was determined at a statistically higher ratio (p = 0.042). In the evaluation of both genes together, a decrease was noted in Gln/Gln + Lys/Gln haplotype frequency in hematological malignancies (p = 0.048). In this study, it was demonstrated that a decrease in Gln/Gln genotype and Gln allele acted as a protector in XPD codon 751 and XRCC1 codon 399 polymorphisms in acute myeloblastic leukemia (AML) and that an increase in Lys/Lys genotype in acute leukemia was associated with early relapse.   Key words: DNA repair, XPD gene, XRCC1 gene, DNA, PCR-RFLP.