The Factor V Gene A4070G Mutation and the Risk of Venous Thrombosis

1999 ◽  
Vol 81 (02) ◽  
pp. 193-197 ◽  
Author(s):  
Viviane Nicaud ◽  
Sophie Gandrille ◽  
Patrick van Dreden ◽  
Jean Amiral ◽  
Marie-Laurence Aubry ◽  
...  

SummaryThe A4070G polymorphism in exon 13 of the factor V (FV) gene, which replaces His by Arg at position 1299 of the B domain, was recently shown to influence circulating FV levels and to contribute to the activated protein C (APC) resistance phenotype. We examined the impact of this polymorphism in a population of unselected patients with venous thromboembolic disease (VTE). The prevalence of the G4070 (R2) allele was determined in 205 patients and 394 healthy subjects of similar age and sex distribution. Thirty-seven patients (18%) were heterozygous for the R2 allele and 1 (0.5%) was homozygous. Forty-four controls (11.2%) were heterozygous for the R2 allele and 1 (0.2%) was homozygous. Thus, the allelic frequency was significantly higher in the patients with VTE than in the healthy controls, with respective values of 9.5% and 5.8%. The odds ratio was 1.8 (95% CI: 1.1-2.8, p = 0.02), pointing to an increased risk of VTE in carriers of the R2 allele. After excluding subjects with putative or confirmed gene defects (mainly the FV R506Q mutation), the R2 allele was still a risk factor for VTE in the remaining patients, with an odds ratio of 2.0 (95% CI: 1.2-3.5, p = 0.01), demonstrating that this polymorphism is itself a risk factor. This study also confirms that the R2 allele influences APC resistance (APCR) in the absence of the FV R506Q mutation.

2002 ◽  
Vol 88 (10) ◽  
pp. 587-591 ◽  
Author(s):  
Karine Lacut ◽  
Grégoire Le Gal ◽  
Patrick Van Dreden ◽  
Luc Bressollette ◽  
Pierre-Yves Scarabin ◽  
...  

SummaryActivated protein C (APC) resistance is the most common risk factor for venous thromboembolism (VTE). Previous studies mostly analysed patients under 70 years and reported a four-to sevenfold increased risk. This case-control study included consecutive patients referred for a clinical suspicion VTE to our medical unit: 621 patients with a well-documented diagnosis (cases) and 406 patients for which the diagnosis was ruled out and who had no personal history of VTE (controls). APC resistance related to factor V Leiden was defined by either a positive DNA analysis or a positive STA® Staclot APC-R assay. Under 70 years, APC resistance was associated with a threefold increased risk of VTE (odds ratio 3.2, 95% CI, 1.7 to 6.0), whereas in patients over 70 years, it appeared to be no longer a strong risk factor (odds ratio 0.8, 95% CI, 0.4 to 1.7). Age appeared as an effectmeasure modifier with a significant interaction (p = 0.005). Our data suggest that APC resistance is not a risk factor for VTE in elderly.


Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
Marieke C.H. de Visser ◽  
Frits R. Rosendaal ◽  
Rogier M. Bertina

Abstract Activated protein C (APC) resistance caused by the factor V Leiden mutation is associated with an increased risk of venous thrombosis. We investigated whether a reduced response to APC, not due to the factor V point mutation, is also a risk factor for venous thrombosis. For this analysis, we used the Leiden Thrombophilia Study (LETS), a case-control study for venous thrombosis including 474 patients with a first deep-vein thrombosis and 474 age- and sex-matched controls. All carriers of the factor V Leiden mutation were excluded. A dose-response relationship was observed between the sensitivity for APC and the risk of thrombosis: the lower the normalized APC sensitivity ratio, the higher the associated risk. The risk for the lowest quartile of normalized APC-SR (<0.92), which included 16.5% of the healthy controls, compared with the highest quartile (normalized APC-SR > 1.05) was greater than fourfold increased (OR = 4.4; 95% confidence interval, 2.9 to 6.6). We adjusted for VIII:C levels, which appeared to affect our APC resistance test. The adjusted (age, sex, FVIII:C) odds ratio for the lowest quartile was 2.5 (95% confidence interval, 1.5 to 4.2). So, after adjustment for factor VIII levels, a reduced response to APC remained a risk factor. Our results show that a reduced sensitivity for APC, not caused by the factor V Leiden mutation, is a risk factor for venous thrombosis.


1997 ◽  
Vol 78 (03) ◽  
pp. 0993-0996 ◽  
Author(s):  
P J Svensson ◽  
G Benoni ◽  
H Fredin ◽  
O Bjӧrgell ◽  
P Nilsson ◽  
...  

SummaryResistance to activated protein C (APC) caused by the R506Q mutation in factor V is the most common inherited risk factor for venous thrombosis. To elucidate whether APC-resistance is a risk factor for venous thrombosis after elective total hip replacement, the association between APC-resistance (presence of FV:Q506 allele) and postoperative thrombosis was investigated in patients (n = 198) randomised to received short (during hospitalisation, n = 100) or prolonged prophylaxis (three weeks after hospitalisation, n = 98) with low molecular weight heparin (LMWH). Among APC-resistant individuals receiving short prophylaxis, 7/10 developed thrombosis as compared to 2/12 receiving long prophylaxis (p <0.0179). Odds ratio for association between APC-resistance and thrombosis in the short prophylaxis group was 4.2 (CI 95% 1.02-17.5) (p <0.0465). Among those receiving prolonged, prophylaxis, there was no increased incidence of thrombosis associated with APC-resistance. Two unexpected observations were made. One was that APC-resistance was much more common in women (19/109) than in men (3/89) (p <0.001). The other was that even women without APC-resistance were much more thrombosis-prone than men. Thus, 24/48 of women with normal FV genotype and short prophylaxis developed thrombosis vs 8/42 among men, p = 0.002. The increased risk of thrombosis associated with female gender and APC-resistance was neutralised by the prolonged treatment. In conclusion, among patients receiving short prophylaxis, female gender was found to be a strong risk factor for venous thrombosis. Even though APC-resistance appeared to be a risk factor for postoperative thrombosis, the uneven distribution of APC-resistance between men and women, taken together with the increased risk of thrombosis among women, precluded valid conclusions to be drawn about the association between APC-resistance and an increased risk of thrombosis. Our results suggest that prolonged prophylaxis with LMWH after hip surgery is more important for women than for men.


2011 ◽  
Vol 106 (11) ◽  
pp. 901-907 ◽  
Author(s):  
Svetlana Tchaikovski ◽  
Margareta Holmström ◽  
Jan Rosing ◽  
Katarina Bremme ◽  
Gerd Lärfars ◽  
...  

SummaryIdentification of patients at high risk of recurrence after a first event of venous thromboembolism (VTE) remains difficult. Resistance to activated protein C (APC) is a known risk factor for VTE, but data on the risk of recurrence is controversial. We wanted to investigate whether APC resistance in the absence of factor V Leiden, determined with global coagulation test such as the thrombin generation assay, could be used as a marker for increased risk of recurrent VTE among women 18–65 years old after a first event of VTE. In a cohort of 243 women with a first event of VTE, plasma was collected after discontinuation of anticoagulant treatment and the patients were followed up for 46 months (median). Thrombin generation was measured via calibrated automated thrombography, at 1 pM and 10 pM of tissue factor (TF). In women without factor V Leiden (n=117), samples were analysed in the absence and in the presence of APC. Increase in ETP (endogenous thrombin potential) and peak height analysed in the presence of APC correlated significantly with higher risk of recurrence. At 1 pM, peak height correlated with increased risk of recurrence. In conclusion, high thrombin generation in the presence of APC, in women after a first event of VTE is indicative for an increased risk of a recurrence. We also found that thrombin generation at low TF (1 pM) is correlated with the risk of recurrence. Our data suggest that APC resistance in the absence of factor V Leiden is a risk factor for recurrent VTE.


Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
Marieke C.H. de Visser ◽  
Frits R. Rosendaal ◽  
Rogier M. Bertina

Activated protein C (APC) resistance caused by the factor V Leiden mutation is associated with an increased risk of venous thrombosis. We investigated whether a reduced response to APC, not due to the factor V point mutation, is also a risk factor for venous thrombosis. For this analysis, we used the Leiden Thrombophilia Study (LETS), a case-control study for venous thrombosis including 474 patients with a first deep-vein thrombosis and 474 age- and sex-matched controls. All carriers of the factor V Leiden mutation were excluded. A dose-response relationship was observed between the sensitivity for APC and the risk of thrombosis: the lower the normalized APC sensitivity ratio, the higher the associated risk. The risk for the lowest quartile of normalized APC-SR (<0.92), which included 16.5% of the healthy controls, compared with the highest quartile (normalized APC-SR > 1.05) was greater than fourfold increased (OR = 4.4; 95% confidence interval, 2.9 to 6.6). We adjusted for VIII:C levels, which appeared to affect our APC resistance test. The adjusted (age, sex, FVIII:C) odds ratio for the lowest quartile was 2.5 (95% confidence interval, 1.5 to 4.2). So, after adjustment for factor VIII levels, a reduced response to APC remained a risk factor. Our results show that a reduced sensitivity for APC, not caused by the factor V Leiden mutation, is a risk factor for venous thrombosis.


2001 ◽  
Vol 85 (02) ◽  
pp. 270-273 ◽  
Author(s):  
Jen-Shiou Lin ◽  
Woei Tsay ◽  
Ming-Ching Shen

SummaryPolymerase chain reaction amplification followed by BstOI enzyme digestion and DNA sequencing was employed to detect the mutation of factor V gene. The subjects consisted of 105 venous thrombophilic patients and 183 healthy controls. Only one patient was found to have factor V Arg306 → Gly mutation, his elder son also had an identical mutation. None of the healthy subjects studied had Arg306 → Thr mutation. The rare event of factor V Arg306 → Gly mutation in patients and controls suggest that this mutation is not associated with increased risk of venous thrombosis. Conventional, modified and extended activated protein C (APC) resistance assays in this patient and his family members clearly showed that factor V Arg306 → Gly mutation is not associated with APC resistance (APC sensitivity ratio <2). In conclusion, factor V Arg306 → Gly mutation is rare in Taiwanese Chinese and not associated with APC resistance, it is possibly not a risk factor for venous thrombophilic thrombosis.


2020 ◽  
Vol 40 (01) ◽  
pp. 012-021
Author(s):  
Björn Dahlbäck

AbstractVenous thromboembolism constitutes a major medical problem afflicting millions of individuals worldwide each year. Its pathogenesis is multifactorial, involving both environmental and genetic risk factors. The most common genetic risk factor known to date is a mutation in the factor V (FV) gene (R506Q or FV Leiden), which impairs the normal regulation of FV by activated protein C (APC). APC is an important regulator of blood coagulation, cleaving and inactivating not only FV/FVa but also activated factor VIII (FVIIIa). In FVa, APC cleaves several sites, Arg506 (R506) being one of them. The R506Q mutation results in the APC resistance phenotype and a lifelong hypercoagulable state. A prothrombin gene mutation is another relatively frequent thrombosis risk factor, whereas deficiencies of the anticoagulant proteins antithrombin, protein C, or protein S are less common. As a result of the high prevalence of FV and prothrombin mutations in the general population, combinations of genetic defects are relatively common. Such individuals have highly increased risk of thrombosis.


1996 ◽  
Vol 75 (02) ◽  
pp. 270-274 ◽  
Author(s):  
Benget Zöller ◽  
Johan Holm ◽  
Peter Svensson ◽  
Björn Dahlbäck

SummaryInherited resistance to activated protein C (APC-resistance), caused by a point mutation in the factor V gene leading to replacement of Arg(R)506 with a Gin (Q), and inherited protein S deficiency are associated with functional impairment of the protein C anticoagulant system, yielding lifelong hypercoagulability and increased risk of thrombosis. APC-resistance is often an additional genetic risk factor in thrombosis-prone protein S deficient families. The plasma concentration of prothrombin fragment 1+2 (F1+2), which is a marker of hyper-coagulable states, was measured in 205 members of 34 thrombosis-prone families harbouring the Arg506 to Gin mutation (APC-resistance) and/or inherited protein S deficiency. The plasma concentration of F1+2 was significantly higher both in 38 individuals carrying the FV:Q506 mutation in heterozygous state (1.7 ± 0.7 nM; mean ± SD) and in 48 protein S deficient cases (1.9 ± 0.9 nM), than in 100 unaffected relatives (1.3 ±0.5 nM). Warfarin therapy decreased the F1+2 levels, even in those four patients who had combined defects (0.5 ± 0.3 nM). Our results agree with the hypothesis that individuals with APC-resistance or protein S deficiency have an imbalance between pro- and anti-coagulant forces leading to increased thrombin generation and a hypercoagulable state.


Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1552-1557 ◽  
Author(s):  
F. Bernardi ◽  
E.M. Faioni ◽  
E. Castoldi ◽  
B. Lunghi ◽  
G. Castaman ◽  
...  

AbstractFactor V gene polymorphisms were investigated to detect components that may contribute to the activated protein C (APC) resistance phenotype in patients with venous thromboembolism. A specific factor V gene haplotype (HR2) was defined by six polymorphisms and its frequency was found to be similar in normal subjects coming from Italy (0.08), India (0.1), and Somalia (0.08), indicating that it was originated by ancestral mutational events. The relationship between the distribution of normalized APC ratios obtained with the functional assay and haplotype frequency was analyzed in patients heterozygous for factor V R506Q (factor V Leiden). The HR2 haplotype was significantly more frequent in patients with ratios below the 15th percentile than in those with higher ratios or in normal controls. Moreover, the study of 10 patients with APC resistance in the absence of the factor V R506Q mutation showed a 50-fold higher frequency of HR2 homozygotes. The HR2 haplotype was associated with significantly lower APC ratios both in patients with venous thromboembolism and in age- and sex-matched controls. However, the two groups showed similar HR2 haplotype frequencies. Plasma mixing experiments showed that an artificially created double heterozygote for the factor V R506Q mutation and the HR2 haplotype had an APC ratio lower than that expected for a simple R506Q heterozygote. Time-course experiments evaluating the decay of factor V in plasma showed the normal stability of the molecule encoded by the factor V gene marked by the HR2 haplotype, which ruled out the presence of a pseudo-homozygous APC resistance mechanism. Our results provide new insights into the presence of factor V genetic components other than the factor V R506Q that are able to contribute to the APC resistance phenotype in patients with venous thromboembolism.


2018 ◽  
Vol 67 (6) ◽  
pp. 50-59 ◽  
Author(s):  
Maria G. Nikolayeva ◽  
Andrey P. Momot ◽  
Marina S. Zaynulina ◽  
Ksenia A. Momot ◽  
Natalia N. Yasafova

Hypothesis/aims of study. The current analysis was undertaken to elucidate the role of Factor Va resistance to proteolytic cleavage by activated protein C in FVL(1691)GA female carriers in the development of acute and recurrent thromboses. Study design, materials and methods. A prospective clinical cohort study of 1100 women of reproductive age was conducted, with the course and outcomes of 2,707 pregnancies analyzed. Two cohorts were specified: the main group consisted of 500 patients with FV(1691)GA genotype, and the control group consisted of 600 patients with FVL(1691)GG genotype. Results. FVL(1691)GA genotype was significantly associated with the development of venous thromboembolic complications (VTEC) compared to FVL(1691)GG genotype (OR 9.3; p < 0.0001). Episodes of recurrent thrombosis during and outside of pregnancy were registered only in FVL(1691)GA patients (OR 5.7, p = 0.2). In all cases, at the time of the thrombotic event and during the period before the episode of acute or recurrent thrombosis, an APC resistance normalized ratio (NR) value was ≤ 0.49, with no episodes of VTEC registered with an APC resistance NR value ≥ 0.5. Conclusion. Venous thromboses occur under the condition of expressed APC resistance with underlying FVL(1691)GA carriage. The APC resistance index can serve as an objective biochemical marker to determine the feasibility of thromboprophylaxis within the framework of personalized medicine.


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