Fibrinogen polymorphisms TaqI, HaeIII and BclI are not associated with a higher risk of deep vein thrombosis.

High fibrinogen is recognised as a risk factor for atherosclerosis. It seems that high fibrinogen is also a risk factor for deep vein thrombosis (DVT). It has been shown that certain polymorphisms in fibrinogen genes can influence the fibrinogen level. In this study, fibrinogen levels and the frequency of the polymorphisms TaqI, HaeIII and BclI were studied in 114 patients with DVT and 244 healthy subjects. In non-smokers, fibrinogen levels above 5 g/l were associated with an increased risk of DVT (odds ratio 3.3, 95% confidence interval 1.6-7.0). The frequencies of common alleles were similar in patients and healthy subjects for all polymorphisms. An association between fibrinogen levels and the polymorphisms TaqI, HaeIII and BclI was found in healthy subjects, but not in the patients. It was concluded from these data that the polymorphisms TaqI, HaeIII and BclI are not major risk factors for DVT.