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[Association of XRCC4 polymorphisms and chromosomal damage levels in 1,3-butadiene workers].

OBJECTIVE
To investigate the association of polymorphisms of DNA double-strand break repair gene XRCC4 and chromosomal damage levels in peripheral blood lymphocyte in workers exposed to 1,3-butadien (BD).


METHODS
189 BD exposed workers and 83 controls were recruited in this study. Chromosomal damage in peripheral lymphocytes was measured by the cytokinesis-block micronucleus (CBMN) assay. Three haplotpe-tagging single nucleotide polymorphisms in XRCC4 gene, including A245G, T1394G and C1475T, were detected by PCR-RFLP and the XRCC4 haplotypes were estimated by using an extension of Clark algorithm. The associations between haplotype pairs and micronuclei data were assessed by analysis of covariance in the exposed and non-exposed groups.


RESULTS
Multivariate analysis of covariance revealed that the frequencies of CBMN, nucleoplasmic bridge (NPB) and nuclear bud (NBUD) were significantly higher in BD exposed workers [(7.17 +/- 5.41) per thousand, (1.20 +/- 1.43) per thousand and (2.87 +/- 2.44) per thousand, respectively] than in the controls [(3.10 +/- 2.56) per thousand, (0.24 +/- 0.66) per thousand and (1.68 +/- 1.92) per thousand, P < 0.01, respectively]. Rank sum test revealed that in BD exposed workers, the XRCC4 A245G AA genotype exhibited higher NPB frequency than that of AG or GG genotypes significantly (P < 0.05). Stratification analysis showed that the polymorphism of XRCC4 T1394G TT carriers had significantly higher CBMN frequencies than those GG carriers (P < 0.01) in < 39 year workers.


CONCLUSION
The results suggested that polymorphisms of XRCC4 A245G and T1394G could influence the chromosomal damage levels in BD exposed workers.