Related Experiment Video
Updated: Aug 20, 2026

Identifying the Effects of BRCA1 Mutations on Homologous Recombination using Cells that Express Endogenous Wild-type BRCA1
Published on: February 17, 2011
[Genetic polymorphisms in X-ray repair cross-complementing gene 1 and susceptibility to papillary thyroid carcinoma]
Qian-Xi Zhu1, Jian-Chao Bian, Qiang Shen
1Department of Epidemiology, School of Public Health, Fudan University, Shanghai 200032, China.
Objective:
To study the association of polymorphisms in the X-ray repair cross-complementing gene 1 (XRCC1) and papillary thyroid carcinoma (PTC).
Methods:
A hospital based, matched case-control study was carried out. The polymorphisms in XRCC1 for 105 pairs of cases with PTC and controls were identified by PCR-RFLP.
Results:
The frequencies of Arg/Arg, Arg/Trp and Trp/Trp genotypes at XRCC1 Arg194Trp site were 47.6%, 49.5% and 2.9% among cases compared to 45.7%, 48.6% and 5.7% among controls. There was no statistically significant difference between the two groups (chi(2) = 1.07, P = 0.59). The frequencies of Arg/Arg, Arg/Gln and Gln/Gln genotypes at XRCC1 Arg399Gln site were 46.7%, 41.9% and 11.4% among cases, while 54.2%, 42.9% and 2.9% among controls respectively. There was statistically significant difference between the two groups (chi(2) = 6.40, P = 0.04). Individuals with Gln/Gln genotype had a 3.65-fold increased risk of developing PTC compared to Arg/Arg genotype (OR = 4.65, 95% CI: 1.24 - 17.45). The multivariate conditional logistic regression analysis showed that the XRCC1 Arg399Gln polymorphism, negative life events and X-irradiation history were associated with PTC, with odds ratios of 2.71 (95% CI: 1.22 - 6.05), 5.34 (95% CI: 1.40 - 20.38) and 0.38 (95% CI: 0.12 - 0.72) respectively. However, XRCC1 Arg194Trp polymorphism, drinking tea, fruit and economic levels did not show statistically significant associations with PTC.
Conclusion:
The Gln/Gln genotype at XRCC1 Arg399Gln site and negative life events significantly increased while X-irradiation history decreased the risk of developing PTC.
Related Concept Videos
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
Nucleotide Excision Repair
Long-patch Base Excision Repair
Mismatch Repair
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
Mutations
Chromosomal Alterations Are Large-Scale Mutations
While point mutations are changes in a single nucleotide in...

