title: First survey of the two polymorphisms (Arg194Trp and Arg399Gln) in XRCC1 gene in four Afghanistan populations and comparison with worldwide data.
abstract: Genetic polymorphisms in gene encoding X-ray repair cross-complementation group 1 (MIM: 194360; XRCC1) have been defined. Previous studies have revealed that there was significant difference between populations for allelic frequency of Arg194Trp (rs. 1799782) and Arg399Gln (rs. 25487) polymorphisms of XRCC1. In order to get more insight into the genetic structure of Afghanistan populations the present study was carried out. Present study was done on 656 (257 Pashtuns, 217 Tajiks, 120 Hazaras, and 62 Uzbeks) unrelated healthy Afghanis refuges living in Fars province (southern Iran). Genotypes for Arg194Trp and Arg399Gln polymorphisms of the XRCC1 were detected by RFLP-PCR method. The prevalence of the 194Trp allele in Pashtuns, Tajiks, Hazaras, and Uzbeks was 0.072, 0.085, 0.108, and 0.145, respectively. The frequency of the 399Gln in Pashtuns, Tajiks, Hazaras, and Uzbeks was 0.362, 0.378, 0.296, and 0.234, respectively. There was significant difference between these ethnic groups for the genotypic distributions of the Arg194Trp (χ(2) = 16.70, df = 6, P = 0.010) and Arg399Gln (χ(2) = 12.67, df = 6, P = 0.049) polymorphisms. Based on the complete dataset, these polymorphisms showed significant linkage disequilibrium. There was significant difference between the ethnic groups for prevalence of the haplotypes (χ(2) = 16.67, df = 6, P = 0.011). Uzbeks showed significant difference with the other ethnic groups (χ(2) = 10.09, df = 2, P = 0.006). The allelic frequencies of 194Trp and 399Gln in Pashtuns and Tajiks seem to be more similar to the Caucasians than the Asian populations. However, Uzbeks seems to be intermediate between Afghanis' Caucasian (Pashtuns and Tajiks) and Asians.
authors.affiliation: Department of Biology, College of Sciences, Shiraz University, 71454, Shiraz, Iran.
authors.forename: Khyber
authors.initials: K
authors.lastname: Saify
authors.forename: Iraj
authors.initials: I
authors.lastname: Saadat
authors.forename: Mostafa
authors.initials: M
authors.lastname: Saadat
mesh_terms: D000346:Afghanistan / Q000208:ethnology; D004268:DNA-Binding Proteins / Q000235:genetics*; D005006:Ethnicity / Q000235:genetics*; D005787:Gene Frequency; D005828:Genetics, Population; D006239:Haplotypes / Q000235:genetics; D006801:Humans; D007492:Iran; D015810:Linkage Disequilibrium; D011110:Polymorphism, Genetic / Q000235:genetics*; 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