NER and BER Repair Gene Polymorphisms in a Healthy North Indian Cohort and Comparison with Different Ethnic Groups Worldwide


Background: Polymorphisms in DNA repair genes are associated with ability to remove DNA lesions, andtherefore may contribute to an individual’s susceptibility to different types of cancer. Base excision repair (BER),and nucleotide excision repair (NER) are the main DNA repair pathways. The present study was conductedto determine the frequency distribution of single nucleotide polymorphisms (SNPs) selected for genes in thesetwo pathways i.e. OGG1 Exon 7 (C1245G), XPC Intron 9 (PAT), and Exon 15 (A33512C) in a North Indianpopulation in comparison with global populations.
Methods: Genotyping was achieved by PCR-based analysis in224 normal healthy, unrelated individuals of similar ethnicity.
Results: Allelic frequencies in wild type of OGG1Exon 7 C>G were 73% (C); XPC PAT D>I 75% (D); and XPC Exon 15 A>C 60.71.9% A. On the other hand, thevariant allele frequency were 27% (G) in OGG1 Exon 7 C>G; 25% (I) in XPC PAT; and 28.1% (C) in XPC Exon15 A>C. Major differences from other ethnic populations were observed.
Conclusions: Our results suggest thatfrequency distribution in these DNA repair genes exhibited a distinctive pattern in our population which couldbe attributed to ethnic variation. This could assist in high-risk screening of humans exposed to environmentalcarcinogens and cancer predisposition in different ethnic groups.