Micronucleus Occurrence Related to Base Excision Repair Gene Polymorphisms in Chinese Workers Occupationally Exposed to Vinyl Chloride Monomer

Objective: To evaluate whether base excision repair gene polymorphisms contributed to susceptibility of chromosomal damage induced by vinyl chloride monomer (VCM). Methods: Cytokinesis block micronucleus test was performed on 185 VCM-exposed workers to detect chromosomal damage in peripheral lymphocytes. The PCR-restriction fragment length polymorphism technique was applied to detect polymorphisms of TDG, PARPl, and APE1 genes. Univariate and multivariate Poisson regression analysis was performed. Results: There was a 1.198 fold increased micronucleus frequency for individuals carrying TDG 199G1y/Ser + Ser/Ser genotypes compared with those carrying Gly/Gly genotype (P < 0.05). Individuals with the combined genotypes of TDG 199G1y/Ser + Ser/Ser and APE1 64Ile/Val + Val/Val had a significantly increased micronucleus frequency compared with those carrying wild-type genotypes for both genes. Conclusion: VCM-exposed workers carrying TDG 199G1y/Ser + Ser/Ser genotypes were susceptible to chromosomal damage. A combination of TDG GLy199Ser and APE1 Ile64Val polymorphisms may modify the risk of chromosomal damage.