ABSTRACT
<p><b>OBJECTIVE</b>To explore association genetic polymorphism of XPD with chromosomal damage in workers exposed to radiation.</p><p><b>METHODS</b>182 workers exposed to radiation for at least one year with chromosomal damage were selected as cases based on a general health examination for all workers exposed to radiation in Tangshan city. The control group without chromosomal damage was matched to case by age (within 5 years), sex, work unit, type of exposed to radiation, cumulate serve length (within 1 year) according to 1:1. The micro whole blood cultivation was used for the chromosome analysis. The chromosome aberration type and rate were observed and counted. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to examine the genotype of three XPD loci (751, 312 and 156).</p><p><b>RESULTS</b>The frequency of XPD 751 AA in cases was higher than that in controls (P < 0.05). The frequency of 751 allele in case group was statistically higher than that in the control groups (P < 0.05). No statistical difference was found in the frequencies of XPD 312 genotype and allele between the case and control group (P > 0.05). 156 mutant gene type in case group was higher than that in the control groups. The frequency of 156 A allele in case group were higher than that of the control groups (P < 0.05). The frequency of genotype with both 751AA and 156CA or 751AA and 156AA was higher in cases than that of controls (P < 0.05).</p><p><b>CONCLUSION</b>XPD 751AA genotype is a possible risk factor for radiation-induced chromosomal damage. XPD 156 mutant gene type is a possible risk factor for radiation-induced chromosomal damage. Individuals with both XPD 751AA and 156 (CA+AA) genotypes are susceptible to radiation-induced chromosomal damage. No association of XPD 312 polymorphism with radiation-induced chromosomal damage is found.</p>