Distribution of XRCC1 genotypes in north Indian population.

ABSTRACT

Background & objectives: XRCC1, a major DNA repair gene, acts as a scaffold of different activities involved in repair by interacting with components of base excision repair (BER) at the site of damage. Polymorphisms in this gene are associated with variations in the repair efficiency which might predispose an individual to cancer risk. To associate a gene polymorphism with disease risk, it is imperative to have the data for its genotype distribution in normal population. The present study was therefore carried out to find distribution of XRCC1 polymorphisms (codons 194, 280 and 399) in normal north Indian population. Methods: Healthy volunteers hailing from north India (150) were enrolled in the study. DNA was isolated from blood samples and genotyping of codons 194, 280 and 399 of XRCC1 gene was done by PCRrestriction fragment length polymorphism (RFLP), using specific primers. Results: The frequencies obtained for heterozygous genotype of codons 194 and 399 were 45 and 49 per cent respectively and were higher than wild and variant genotypes. For codon 280, the highest frequency (59%) was obtained for the wild genotype. Frequencies of the variant genotypes of codons 194 and 399 were higher in males and females respectively. The allele frequencies also followed the similar trends. Interpretation & conclusions: A significant distribution of variant and heterozygous XRCC1 genotypes was noticed that warrants further studies on the association between these genotypes and disease risk in our study population.