OBJECTIVETo explore the relationship between genetic polymorphisms of CYP-1A1 and CYP2D6 and risks of chronic benzene poisoning (BP).

METHODSA case control study was conducted. 152 BP patients and 152 workers occupationally exposed to benzene without poisoning manifestations were involved. Polymerase chain reaction followed by restriction fragment length polymorphism (PCR-RFLP) technology was used for detecting the single nucleotide polymorphisms (SNPs) of MspI in the non-coding region of CYP-1A1 gene and c.188, g.212 position in the first extron of CYP2D6 gene.

RESULTSThe individuals with CYP1A1 MspI T/T genotype had a 1.32 times (95% CI: 1.05 approximately 1.65, P = 0.02) increased risk of BP compared with those carrying T/C and C/C genotypes. In no-smoking population, there was a 1.56 times (95% CI: 1.15 approximately 2.12, P = 0.003) increased risk of BP for subjects carrying CYP1A1 MspIT/T genotype compared with those carrying T/C and C/C genotypes. The individuals carrying CYP2D6 c.188 C/C or C/T genotype had a 1.23 times (95% CI: 1.05 approximately 1.42, P = 0.01) increased risk compared with those carrying T/T genotypes. In no-smoking population, there was a 1.23 times (95% CI: 1.04 approximately 1.47, P = 0.01) increased risk of BP for subjects carrying CYP2D6 c.188 C/C or C/T genotypes compared with those carrying T/T genotype. The single nucleotide polymorphism of g.212 position in the first extron of CYP2D6 gene had not been validated.

CONCLUSIONThe individuals with CYP2D6 c.188 C/C, CYP2D6 c.188 C/T and CYP1A1 MspIT/T genotypes tend to be more susceptible to benzene toxicity.