ABSTRACT
<p><b>OBJECTIVE</b>To explore the relation between genetic polymorphisms of NQO1, GSTT1 and risks of chronic benzene poisoning (BP).</p><p><b>METHODS</b>A case-control study was conducted. 152 BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were investigated. Polymerase chain reaction (PCR), denaturing high-performance liquid chromatography(DHPLC) and sequencing were used to detect the single nucleotide polymorphisms(SNPs) of the promoter and complete coding-region of NQO1 gene. Multiple PCR was used to detect GSTT1 genotype.</p><p><b>RESULTS</b>In smoking population, there was 7.73-fold (95% CI: 1.71-34.97, P = 0.010) of risk in BP subjects carrying NQO1c. 609 T/T genotype, compared with those carrying C/C and C/T. genotype. In drinking population, the individuals carrying the 6th extron of NQO1c. 609 T/T homozygote genotype had a 11.00-fold(95% CI: 1.89-63.83, P = 0.005) risk of BP compared to those with NQO1c. 609 C/T and C/C genotypes.</p><p><b>CONCLUSION</b>The subjects carrying NQO1c. 609 T/T genotype and together with the habit of smoking or drinking may be more susceptible to BP.</p>