Age- and Gender-Independent Association of XRCC1 Arg399Gln Polymorphism with Chronic Myeloid Leukemia

Abstract
Purpose
DNA damage to hematopoietic progenitor cells is an essential factor for leukemia development as a failure of the host DNA repair system to fix errors in DNA. This study aimed to assess the association of XRCC1 gene polymorphisms including Arg194Trp, Arg399Gln, and Arg280His with the risk of development of CML in Sudanese population.

Patients and Methods
The present study was conducted on 186 newly diagnosed patients with CML, aged 19–70 years (118 males and 68 females; mean age of 46.15±13.91 years) and 186 normal healthy controls (123 males and 63 females; mean age of 44.94±8.97 years). Polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay was utilized to analyze the XRCC1 (Arg194Trp, Arg399Gln, and Arg280His) gene polymorphisms.

Results
The genotypic frequencies of Arg399Gln polymorphism in cases were 131 (70.4%) homozygous Arg/Arg, 46 (24.7%) homozygous Gln/Gln, and 9 (4.8%) heterozygous Arg/Gln as compared to the controls ie, 153 (82.3%), 73 (14.5%), and 6 (3.2%), respectively. The Arg399Gln variant genotypic frequencies significantly differed between the cases and controls (χ2 = 7.249, P = 0.027). By comparison, no statistically significant difference was observed in the variant genotype frequencies between the cases and controls in terms of Arg194Trp and Arg280His polymorphisms.

Conclusion
XRCC1 Arg399Gln gene polymorphism might have an important role in increasing the risk of chronic myeloid leukemia among Sudanese patients. Furthermore, all tested three polymorphisms showed no association of risk of the development of CML with age and gender.