Search

Several polymorphisms in the XRCC5 (X-ray repair cross-complementing 5; OMIM: 194364) were reported. Polymorphism of variable number of tandem repeats (VNTR) in the promoter region of XRCC5 (rs6147172) was reported. The main aim of the present study is to introduce the high resolution melting analysis (HRMA) method for genotyping of the polymorphism of XRCC5 VNTR. Genotypes of XRCC5 VNTR were determined by HRMA and conventional PCR method, and confirmed by DNA sequencing. The results for genotyping using HRMA and conventional PCR showed 100% concordance. All genotypes of the XRCC5 VNTR polymorphism could be accurately detected by HRMA.

Polymorphism of variable number of tandem repeats (VNTR) in the promoter region of X-ray repair cross-complementing 5 ( XRCC5 ; MIM: 194364, rs6147172) has been reported. The main aim of the present study is to introduce a novel allele for the VNTR polymorphism in the promoter region of XRCC5 . The participants of the present study were of 535 (140 males, 395 females), unrelated, adult, healthy Iranian blood donors (Caucasians/Muslims). Genotypes of XRCC5 VNTR were determined by a high resolution melting analysis, and confirmed by DNA sequencing. Based on the sequencing of new bands upper than the 2R allele band, a novel allele was introduced (named 3R allele). The promoter region of XRCC5 contains several copies of Sp1 recognition cis regulatory elements. The novel 3R allele is capable of expanding the number of cis regulatory elements to eight. The prevalence of the 0R, 1R, 2R and 3R alleles in our sample was 0.0645, 0.5439, 0.3794 and 0.0122, respectively. The study group was at the Hardy–Weinberg equilibrium for the genotypic frequencies ( χ 2 = 3.95, d f = 6, P = 0.73). It is suggested that the prevalence of the novel allele (3R allele) among European populations may be higher than its prevalence among Iranians.

The main aim of the present study was to investigate the association between several genetic polymorphisms (in glutathione S-transferase members and DNA repair genes) and clinical response to chemotherapy in locally advanced breast cancer. A sequential series of 101 patients were prospectively included in this study. Clinical assessment of treatment was accomplished by comparing initial tumor size with preoperative tumor size using revised RECIST guideline (version 1.1). Clinical response was regarded as a response or no response. There was no difference between non-responders and responders for the prevalence of genotypes of the study polymorphisms.

Polymorphism of variable number of tandem repeats (VNTR) in the promoter region of X-ray repair cross-complementing 5 (MIM: 194364, XRCC5 ; rs6147172) was reported. The aim of the present study is to evaluate the influence of this polymorphism on XRCC5 mRNA levels. Genotypes of XRCC5 VNTR were determined by high resolution of melting analysis (HRMA). The quantitative XRCC5 mRNA expression (compared to s-actin expression) among 0R/1R, 1R/2R, and 1R/3R genotypes was investigated. There was a negative correlation between the overall number of tandem repeats and XRCC5 expression ( r = −0.965, df = 7, P XRCC5 decreased as function of number of tandem repeats. The 3R allele of the VNTR polymorphism in the XRCC5 promoter region dramatically decreases the gene expression.