title: Genetic polymorphisms of DNA repair gene: XRCC1 Pro206Pro and Gln632Gln in a Chinese Han population.
abstract: DNA repair genes are increasingly studied because of their critical role in maintaining genome integrity. The base excision repair (BER) pathway is a DNA repair pathway that operates on small lesions, such as oxidized or reduced bases, fragmented or nonbulky adducts, or those produced by methylating agents. The XRCC1 polymorphic system is the key gene of the BER pathway. In this study, polymorphisms of XRCC1 Pro206Pro on exon 7 and Gln632Gln on exon 17 were analyzed in a northeastern Chinese Han population. Genomic DNA extracted from 303 unrelated individuals and the PCR-RFLP technique were used to identify variants. The allele frequencies were 0.90 (A) and 0.10 (G) for XRCC1 Pro206Pro and 0.88 (G) and 0.12 (A) for XRCC1 Gln632Gln. The genotype frequencies were 0.797 (AA), 0.203 (AG), and 0 (GG) for XRCC1 Pro206Pro and 0.007 (AA), 0.222 (AG), and 0.771 (GG) for XRCC1 Gln632Gln. The expected heterozygosity and PIC were 18 and 16.38% for Pro206Pro and 21.12 and 18.89% for Gln632Gln. The two polymorphisms were in strong linkage disequilibrium (D' = 0.921, r (2) = 0.735). The results are compared with those of other reported populations. They showed marked ethnic group differences. This study provides the first analysis of the distribution of allele frequency for XRCC1 Pro206Pro and Gln632Gln in a Chinese population.
authors.affiliation: Key Laboratory of Environment and Population Health of Liaoning Education Ministry, Shenyang Medical College, Shenyang, Liaoning Province, P.R. China. yinjyf@yahoo.com.cn
authors.forename: Jiaoyang
authors.initials: J
authors.lastname: Yin
authors.forename: Rong
authors.initials: R
authors.lastname: Qi
authors.forename: Yegang
authors.initials: Y
authors.lastname: Ma
authors.forename: Zhongfu
authors.initials: Z
authors.lastname: Sun
authors.forename: Huiwen
authors.initials: H
authors.lastname: Wang
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D044466:Asian People; D002681:China; D004260:DNA Repair / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D005091:Exons / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D015894:Genome, Human / Q000235:genetics; D042822:Genomic Instability / Q000235:genetics; D005838:Genotype; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human