Objectives: Evaluation of the frequency of X-ray Cross Complementing group 1 (XRCC1) Arg399Gln polymorphism
among patients with end-stage renal disease (ESRD) patients and to determine if a possible association was
present.
Subjects & methods: Blood samples were obtained from 70 ESRD patients and 30 healthy volunteers as control
group for routine laboratory investigations and genomic DNA was extracted using GeneJET Whole Blood DNA
Purification Kit to detect XRCC1 codon 399 genotype Arg/Gln in exon 10. BCNL digestion resulted in two
fragments of 389 and 121 bp for wild-type homozygous (Arg/Arg); one fragment of 510 bp for variant homozygous (Gln/Gln); and three fragments of 510, 389 and 121 bp for variant heterozygous (Arg/Gln).
Results: Compared to control subjects, ESRD patients showed significantly higher frequency of Arg/Gln genotype,
but had significantly lower frequency of Arg/Arg genotype. Moreover, patients had significantly lower frequency
of Arg allele in comparison to controls (57.1% vs. 83.3%, respectively). Furthermore, the frequency of recessive
models; Gln/Gln + Arg/Gln was significantly higher, while the frequency of dominant models; Arg/Arg + Arg/
Gln was non-significantly lower among patients than controls. Development of ESRD was positively correlated
with the presence of XRCC1 Arg/Gln genotype, while was negatively correlated with the presence of XRCC1 Arg/
Arg genotype. ROC curve analysis showed that presence of XRCC1 Arg/Arg genotype is a negative sensitive
predictor, while XRCC1 Arg/Gln genotype is a positive significant predictor for development of ESRD and
Regression analysis defined presence of XRCC1 Arg/Arg genotype as significant negative predictor for development of ESRD.
Conclusion: The results of the current study indicated an intimate relation between XRCC1 gene polymorphism
and development of ESRD and the predictive value of its presence for the possibility of progression of chronic
kidney disease to ESRD stage |
