In the same individuals, we also evaluated the frequency of the coexistence of C677TMTHFR with mutant factor V:Q506, a common risk factor for deep-vein thrombosis.
To determine if the deep vein thrombosis was of genetic origin, a peripheral blood DNA sample was analysed for the presence of the three most frequent mutations associated with thrombotic events: factor V Leiden (1691G>A), prothrombin (20210G>A) and methylene tetrahydrofolate reductase (677C>T).
Patients with prothrombinG20210A had a younger age at their first VTE (24 years, P < 0.0001) and a higher rate of DVT accompanying PE (P = 0.04) than those with FV Leiden or no thrombophilia.
We studied the association between the 1601G/A polymorphism, FSAP activity, FSAP antigen, Factor VIIa (FVIIa), prothrombin fragment 1+2 (F1+2), and C-reactive protein (CRP) in plasmas of 170 patients suspected for DVT.
We determined the prevalence of factor V Leiden and of prothrombinG20210A mutations in a cohort of unselected outpatients (n = 748) referred for suspected deep vein thrombosis (DVT) and/or pulmonary embolism (PE) and a pooled analysis of similar studies was also performed.
Higher D-dimer concentration was associated with the risk of DVT, and was supra-additive to the risks associated with factor V Leiden and the prothrombin 20210A variant.
Women carrying the factor V Leiden (F5 rs6025) polymorphism, or who had reduced sensitivity to activated protein C (aPC) in the absence of F5 rs6025, had increased risk for DVT, with unadjusted ORs 7.7 (95% CI 4.7-12.7) and 3.5 (95% CI 2.2-5.4), respectively.
The adjusted odds ratio for upper-extremity DVT was 6.2 (95% CI 2.5 to 15.7) for factor V Leiden, 5.0 (95% CI 2.0 to 12.2) for prothrombinG20210A, and 4.9 (95% CI 1.1 to 22.0) for the anticoagulant protein deficiencies.
A novel sequence variation in the 3'-untranslated region of the prothrombin (factor II) gene (nucleotide 20210 G-->A) has been recently described as a risk factor for deep vein thrombosis and pulmonary embolism.
The adjusted odds ratio for upper-extremity DVT was 6.2 (95% CI 2.5 to 15.7) for factor V Leiden, 5.0 (95% CI 2.0 to 12.2) for prothrombin G20210A, and 4.9 (95% CI 1.1 to 22.0) for the anticoagulant protein deficiencies.
We calculated the prevalences of prothrombin G20210A, factor V G1691A (also associated with high risk for DVT) and homozygous methylenetetrahydrofolate reductase (MTHFR) C677T (associated with increased susceptibility to develop hyperhomocysteinemia) in 118 patients with a first episode of DVT and in 416 healthy controls.
In the general population, ProthrombinG20210A heterozygotes had1.3 (95% CI:0.6-2.9) fold risk for VTE, 0.6 (0.2-2.0) for DVT, 1.7(0.6-4.8) for PE, 1.5(1.1-2.1) for IHD, 1.7(1.1-2.7) for MI, 1.1(0.6-1.9) for ICVD, and 1.1(0.5-2.1) for IS compared to non-carriers.
Patients with recurrent DVT or a family history of DVT were significantly (p<0.0001) more likely to have the prothrombin mutation than other DVT patients.