Association of DNA Damage Repair Gene Polymorphisms hOGG1, XRCC1and p53 with Sickle Cell Disease Patients in India

Background: Oxidative stress constitutes one of the significant cause of vaso-occlusive clinical episodes in sickle cell disease (SCD) patients. It brings about the generation of reactive oxygen species and consequent damage to DNA. DNA damage repair genes such as hOGG1, XRCC1 and p53 play an important role in the repair of DNA damage during oxidative stress. However, it is not known as to the role of these genes in oxidative stress mediated vaso-occlusive clinical complications of SCD patients. Objective: To see the possible association of DNA repair gene polymorphisms with clinical manifestation of SCD patients. Methods: Genotyping of DNA damage repair genes by PCR-RFLP, measurement of oxidant and anti-oxidant status, along with a clinical evaluation of 250 SCD patients and their comparison with normal individuals. Result: The level of oxidants were high, and that of antioxidants were low in SCD patients compared to normal individuals. The prevalence of mutant alleles of hOGG1 gene, XRCC1 gene (codon 280 Arg>His) were found to be significantly higher among SCD patients as compared to controls. However, SCD patients did not show clinical association with any of these DNA repair gene polymorphisms. Conclusion: This indicates that hOGG1, p53and XRCC1 gene polymorphisms have no clinical association with SCD patients in India.