An interethnic variability and a functional prediction of DNA repair gene polymorphisms: the example of XRCC3 (p.Thr241>Met) and XPD (p.Lys751>Gln) in a healthy Tunisian population

Mol Biol Rep. 2012 Oct;39(10):9639-47. doi: 10.1007/s11033-012-1829-z. Epub 2012 Jun 28.

Abstract

Genetic polymorphisms in DNA repair genes might influence the repair activities of the enzymes predisposing individuals to cancer risk. Owing to the presence of these genetic variants, interethnic differences in DNA repair capacity have been observed in various populations. The present study was undertaken to determine the allele and genotype frequencies of two common non-synonymous SNPs, XRCC3 p.Thr241>Met (C > T, rs861539) and XPD p.Lys751>Gln (T > G, rs13181) in a healthy Tunisian population and to compare them with HapMap ( http://www.hapmap.org/ ) populations. Also, we predicted their eventual functional effect based on bioinformatics tools. The genotypes of 154 healthy and unrelated individuals were determined by PCR-RFLP procedure. Our findings showed a close relatedness with Caucasians from European ancestry which might be explained by the strategic geographic location of Tunisia in the Mediterranean, thus allowing exchanges with Europeans countries. The in silico predictions showed that p.Thr241>Met substitution in XRCC3 protein was predicted as possibly damaging, indicating that it is likely to have functional consequences as well. To the best of our knowledge, this is the first study in this regard in Tunisia. So, these data could provide baseline database and help us to explore the relationship of XRCC3 and XPD polymorphisms with both cancer risk and DNA repair variability in our population.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Amino Acid Sequence
  • Amino Acid Substitution*
  • Computational Biology
  • Conserved Sequence
  • DNA-Binding Proteins / genetics*
  • Female
  • Gene Frequency
  • Genotype
  • Health
  • Humans
  • Male
  • Middle Aged
  • Models, Molecular
  • Molecular Sequence Data
  • Phylogeography
  • Polymorphism, Restriction Fragment Length
  • Polymorphism, Single Nucleotide*
  • Sequence Analysis, DNA
  • Tunisia
  • Xeroderma Pigmentosum Group D Protein / genetics*
  • Young Adult

Substances

  • DNA-Binding Proteins
  • X-ray repair cross complementing protein 3
  • Xeroderma Pigmentosum Group D Protein
  • ERCC2 protein, human