DNA repair genes polymorphisms in multiple myeloma: no association with XRCC1 (Arg399Gln) polymorphism, but the XRCC4 (VNTR in intron 3 and G-1394T) and XPD (Lys751Gln) polymorphisms is associated with the disease in Turkish patients

OBJECTIVE: This study aims to investigate the association between the polymorphisms in DNA repair genes (XPD, XRCC1, and XRCC4) and clinical parameters in patients with multiple myeloma (MM), their effects on prognosis and their roles in susceptibility to MM. Patients and methods: Sixty patients, diagnosed with MM and 70 individuals as the healthy control group were included in the study. Gene polymorphisms were detected with the polymerase chain reaction and/or polymerase chain reaction-restriction fragment length polymorphism method. When the genotype frequencies of XPD (Llys751Gln) and XRCC1 (Arg399Gln) genes were examined in the patient and control groups, no significant difference was detected, while a significant association was found in XRCC4 (VNTR in intron 3 and G-1394T) polymorphisms. A significant association was found in the MM patients group for AA genotype and event-free survival (EFS) in terms of XPD (751) gene polymorphism (P = 0.047). When VNTR intron 3 polymorphism was compared for genotype frequency, DD genotype was found to be significantly low (P = 0.012) in the patient group, whereas GG and TT genotypes were found to be significantly lower in the patient group for the genotype frequency XRCC4 (G-1394T) polymorphism when compared to the control group (P = 0.015, P = 0.010, respectively). RESULTS: These data provide support for the hypothesis that a common variation in the genes encoding XRCC4 DNA repair proteins may contribute to susceptibility to myeloma. These findings require further validation in independent populations.