Summary
Since CYP1A1 enzyme is involved in metabolism of tobacco carcinogens, the CYP1A1 gene
may be of relevance to smoking-induced differences in the risks of venous thromboembolism
(VTE). We conducted a case-control study to investigate genetic polymorphisms in CYP1A1
that might modify the risk of developing VTE. A total of 425 Chinese patients with
VTE and 527 VTE-free control individuals, matched by age and gender, were included
in this analysis. The MspI and Ile462Val polymorphisms in CYP1A1 gene were analysed
using the Amplification Refractory Mutation System (ARMS) method. The Ile462Val AG
variant and combined AG and GG variant was significantly associated with VTE, adjusted
for age, gender, weight and contraceptives (OR=1.362, 95%CI 1.026, 1.809, p=0.033;
OR=1.420, 95% CI 1.081, 1.865, p=0.012, respectively); The AG and GG combined variant
was still significantly associated with VTE when adjusting further for smoking (OR=1.344,
95%CI 1.019,1.772, p=0.036) A more than two-fold increase for VTE was associated with
the Ile462Val combined variant of AG+GG (OR of 2.805, 95% CI 1.250, 6.293, p=0.012)
in the smokers. Genetic variations of CYP1A1 Ile462Val contribute to susceptibility
to smoking-induced VTE in the Chinese populations. A two-fold increase in the risk
in the smokers in the patients who carry CYP1A1 Ile462Val variant alleles has demonstrated
the importance of gene-environment interactions in the development of this disease.
Keywords
CYP1A1 - smoking - venous thromboembolism - ARMS - Chinese