Pterygium and genetic polymorphisms of the DNA repair enzymes XRCC1, XPA, and XPD

[摘要] Purpose: Pterygium is an ultraviolet(UV) related disease. UV radiation can produce DNA damage, which isrepaired by the DNA repair systems. Among the DNA repair systems, thebase excision repair (BER) and nucleotide excision repair (NER) systemsare the major ones involved in repairing UV-induced DNA damage; X-rayrepair cross complementary 1 (XRCC1) and human 8-oxoguanine DNAglycosylase 1 (hOGG1) are two BER genes, and xerodermapigmentosum group A (XPA) and xeroderma pigmentosum group D (XPD)are two NER genes. Polymorphisms of these genes are associated with thedifferences in their repair DNA damage capacity, and they modulate thesusceptibility to cancer. Because the polymorphism of hOGG1 wasreported to be associated with pterygium, it is logical to assume thecorrelation between XRCC1, XPA, and XPDpolymorphisms and pterygium formation. Methods: One hundred and twenty-sevenpterygium patients and 103 volunteers without pterygium were enrolledin this study. Polymerase chain reaction based analysis was used toresolve the XRCC1 codon 107, 194, 280, and 399; XPAA23G; XPA codon 228; and XPD codon 751 polymorphisms. Results: There were significantdifferences in the frequency of genotypes and alleles of XRCC1codon 194 and 399 polymorphisms between the groups. In codon 194,individuals who carried at least 1 Trp allele had a decreased risk ofdeveloping pterygium compared to those who carried the Arg/Argwild-type genotype (odds ratio [OR]=0.58; 95% CI: 0.34–0.98). In codon399, individuals who carried at least 1 Gln allele had a threefoldincreased risk of developing pterygium compared to those who carriedthe Arg/Arg wild-type genotype (OR=3.06; 95% CI: 1.78–5.26). There wereno significant differences in the frequency of the genotypes andalleles of XRCC1 codon 107 and 280, XPA A23G, and XPDcodon 751 polymorphisms between the groups. The XPA codon 228polymorphism was not detected in any of the cases or controls. Conclusion: The XRCC1 codon 194polymorphism causes a decreased risk of developing pterygium, but thecodon 399 polymorphism increases the risk. There is no correlationbetween pterygium and XRCC1 codon 107 and 280, XPAA23G, and XPD codon 751 polymorphisms.

[学科分类] 生物化学/生物物理