Vettriselvi V, Vijayalakshmi K, Solomon Paul F D, Venkatachalam P
Department of Human Genetics, Sri Ramachandra University, Porur, Chennai, Tamil Nadu, India.
Asian Pac J Cancer Prev. 2007 Apr-Jun;8(2):283-6.
DNA repair systems play an important role in maintaining the integrity of the human genome. Deficiency in the repair capacity due to either mutations or inherited polymorphisms in DNA repair genes may contribute to variations in the DNA repair capacity and subsequently susceptibility to cancer. The interindividual variability as well as ethnic differences in DNA repair polymorphisms, stress the importance to establish genotype profiles unique to a population. Hence the present study aimed to determine the frequencies of XRCC1 and XPD gene polymorphisms in 255 healthy random unrelated individuals from South India. DNA was isolated from the peripheral blood sample of these individuals and the XRCC1 and XPD genotypes were determined by PCR- RFLP with Msp1 and Pst1 enzymes respectively. The XRCC1 genotype frequencies revealed 36% Arg/Arg, 47% Arg/Gln and 17% Gln/Gln with Gln allele frequency of 0.41. Analysis of XPD genotypes revealed 51% Lys/Lys, 41% Lys/Gln and 8% Gln/Gln with Gln allele frequency of 0.29. No significant difference in the distribution of genotypes was seen based on gender. Comparison of the frequencies of XRCC1 and XPD polymorphisms observed in the present study with other populations revealed a distinctive nature of the South Indian population. An understanding of DNA repair gene polymorphisms might not only enable risk assessment of humans exposed to environmental carcinogens but also response to therapy, which target the DNA repair pathway.
DNA修复系统在维持人类基因组完整性方面发挥着重要作用。由于DNA修复基因的突变或遗传多态性导致的修复能力缺陷，可能会导致DNA修复能力的差异，进而增加患癌易感性。DNA修复多态性的个体间变异性以及种族差异，凸显了建立特定人群独特基因型谱的重要性。因此，本研究旨在确定来自印度南部的255名健康随机无关个体中XRCC1和XPD基因多态性的频率。从这些个体的外周血样本中分离出DNA，并分别用Msp1和Pst1酶通过PCR-RFLP确定XRCC1和XPD基因型。XRCC1基因型频率显示，36%为Arg/Arg，47%为Arg/Gln，17%为Gln/Gln，Gln等位基因频率为0.41。XPD基因型分析显示，51%为Lys/Lys，41%为Lys/Gln，8%为Gln/Gln，Gln等位基因频率为0.29。基于性别，基因型分布未见显著差异。将本研究中观察到的XRCC1和XPD多态性频率与其他人群进行比较，发现印度南部人群具有独特性。了解DNA修复基因多态性不仅有助于评估暴露于环境致癌物的人类的风险，还能了解针对DNA修复途径的治疗反应。
