Association between Polymorphisms of XRCC1 and TP53 Genes and Endometriosis

Abstract

Endometriosis is a complex disorder of the female reproductive system where endometrial tissue embeds and grows at extrauterine location. Polymorphisms in several genes have been studied as probable risk factors of this debilitating disease. Aims: To investigate the association between poly¬morphisms in DNA repair pathway genes, namely XRCC1 Arg399Gln and TP53 codon 72 and risk of developing endometriosis. Study Design: The study was conducted at Medical Biochemistry Department, Menoufia University and Obstetrics and Gynecology Department, Mansoura University between May 2012 and June 2014. Methodology: Genotyping of XRCC1 Arg399Gln by PCR-CTPP and TP53 codon 72 using allele-specific PCR techniques were conducted on 85 endometriosis patients and 60 healthy controls. Results: This study found that TP53 Pro/Pro and XRCC1 399 Gln/Gln homozygotes had a 5.11 and 4.19 fold increased risk to develop endometriosis when compared to the arginine homozygotes, respectively. This association between TP53 codon 72 Pro/Pro genotype and the risk of endometriosis was also clearly evident in endometriosis patients with stage III and IV (4.6 fold increased risk to develop endometriosis). However, the association between XRCC1 399 Gln/Gln genotype and endometriosis stage was not statistically significant (P=0.16). Anon significant higher risk of endometriosis was associated with the presence of two risk genotypes, with OR values of 1.6 (95% CI = 0.64-3.8). Conclusion: It could be concluded that XRCC1 399Gln and TP53 72Pro alleles are significantly associated with an increased risk for endometriosis. More than one gene variant didn't significantly increase the risk of endometriosis. Therefore, further larger population-based studies including other DNA repair pathway genes are needed in order to confirm the possible relationship between DNA repair gene polymorphisms and endometriosis risk.