Association between POLG and XRCC1 gene polymorphisms and keratoconus occurrence among Egyptian patients

Abstract

Abstract Background Keratoconus is a progressive disorder distinguished by thinning of the corneal tissue and bulging forward into a cone-shaped fashion. Yet its aetiology, which is multifactorial, despite intensive research remains elusive. Corneal exposure a reactive oxygen species causing oxidative DNA damage has been reported to be associated with QC and therefore suggesting that DNA base excision repair mechanism might lie behind the pathogenesis of the disease. Methods We studied the association of three variants in two REB genes (XRCC1 and POLG) and QC occurrence in a cohort of patients from Egypt. Genotyping of the three variants was performed using PCR and restriction enzymes analyses. Results We observed that A allele and A/A genotype of the c.1196A>G variant in the XRCC1 gene were significantly associated with increased QC occurrence while the G allele was associated with decreased QC occurrence. Similarly, the A/A genotype of the c.-1370T>A polymorphism in the POLG gene and the A allele were associated with increased occurrence of QC, while T/A genotype and the T allele were accompanied with decreased occurrence of QC. On the other hand, no association was observed between the c.580C>T variant in the XRCC1 gene and QC occurrence among the studied group of patients. Conclusion Our results suggest that c.1196A>G variant of the XRCC1 and c.-1370T>A variant of the POLG gene may be involved in QC pathogenesis and might be considered as a genetic risk factors of the disease among Egyptian population.