Polymorphisms in the protein C gene as risk factor for venous thrombosis

2009 ◽  
Vol 101 (01) ◽  
pp. 62-67 ◽  
Author(s):  
Carine Doggen ◽  
Hans Vos ◽  
Pieter Reitsma ◽  
Frits Rosendaal ◽  
Elisabeth Pomp
Keyword(s):  
Oral Contraceptive ◽  
Venous Thrombosis ◽  
Protein C ◽  
Contraceptive Use ◽  
Factor V Leiden ◽  
Factor V ◽  
Thrombotic Risk ◽  
Control Subjects ◽  
Oral Contraceptive Use ◽  
Increased Risk

SummaryProtein C is an important inhibitor of blood coagulation. We investigated the effect of two polymorphisms within the promoter region of the protein C gene (C/T at position 2405 and A/G at position 2418) on risk of venous thrombosis and on plasma protein C levels. In addition the combined effect of the two polymorphisms with factor V Leiden and oral contraceptive use was investigated. Previous studies on these polymorphisms were small and were not able to investigate synergistic effects. In the Multiple Environmental and Genetic Assessment of risk factors for venous thrombosis (MEGA study), protein C levels were determined in 2,043 patients with venous thrombosis and 2,857 control subjects, and the two polymorphisms in 4,285 patients and 4,863 control subjects. The CC/GG genotype was associated with the lowest protein C levels. Compared to carriers of the TT/AA genotype – a genotype associated with higher protein C levels – the risk of venous thrombosis in CC/GG carriers was 1.3-fold increased (95% confidence interval 1.09–1.48). The combination of factor V Leiden with the CC/GG genotype led to a 4.7-fold increased risk, compared to non-carriers with the TT/AA genotype. Oral contraceptive use together with the CC/ GG genotype resulted in a 5.2-fold increased risk. In conclusion, the CC/GG genotype is associated with lower levels of protein C and an elevated risk of venous thrombosis compared to the TT/AA genotype. There is no clear synergistic effect of the CC/ GG genotype with factor V Leiden or oral contraceptive use on thrombotic risk.

Pulmonary embolism and deep venous thrombosis during pregnancy or oral contraceptive use: Prevalence of factor V Leiden

1996 ◽  
Vol 131 (6) ◽  
pp. 1145-1148 ◽  
Author(s):  
Denise R. Hirsch ◽  
Katriina M. Mikkola ◽  
Peter W. Marks ◽  
Edward A. Fox ◽  
David M. Dorfman ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
Oral Contraceptive ◽  
Venous Thrombosis ◽  
Deep Venous Thrombosis ◽  
Contraceptive Use ◽  
Factor V Leiden ◽  
Factor V ◽  
Oral Contraceptive Use

Incidence of Venous Thromboembolism in Families with Inherited Thrombophilia

1999 ◽  
Vol 81 (02) ◽  
pp. 198-202 ◽  
Author(s):  
Paolo Simioni ◽  
Bernd-Jan Sanson ◽  
Daniela Tormene ◽  
Philip Friederich ◽  
Bruno Girolami ◽  
...  
Keyword(s):  
Risk Factors ◽  
Venous Thromboembolism ◽  
Oral Contraceptive ◽  
Contraceptive Use ◽  
Post Partum ◽  
Family Members ◽  
Factor V Leiden ◽  
Factor V ◽  
Relative Risks ◽  
Oral Contraceptive Use

SummaryThe risk of spontaneous or risk-period related venous thromboembolism in family members of symptomatic carriers of antithrombin (AT), protein C (PC) or protein S (PS) defects, as well as of the Factor V Leiden mutation is still undefined. We performed a retrospective cohort study in family members (n = 793) of unselected patients with a documented venous thromboembolism and one of these deficiencies to make an estimate of this risk. The annual incidences of total and spontaneous venous thromboembolic events in carriers of AT, PC or PS defects (n = 181) were 1.01% and 0.40%, respectively, as compared to 0.10% and 0.04% in non-carriers, respectively (relative risks both 10.6). In carriers of Factor V Leiden (n = 224), the annual incidences of total and spontaneous venous thromboembolism were 0.28% and 0.11%, respectively, as compared to 0.09% and 0.04% in non-carriers, respectively (relative risks 2.8 and 2.5). Additional risk factors (immobilisation, surgery and trauma; oral contraceptive use; and pregnancy/ post-partum) increased the risk of thrombosis in carriers of AT, PC and PS defects as compared to non-carriers (relative risks 8.3, 6.4 and 8.2, respectively). Oral contraceptive use and pregnancy/ post-partum period increased the risk of thrombosis in carriers of Factor V Leiden to 3.3-fold and 4.2-fold, respectively, whereas other risk factors had only a minor effect.These data lend some support to the practice of screening family members of symptomatic carriers of a AT, PC and PS deficiency. For family members of symptomatic carriers of Factor V Leiden, screening does not seem to be justified except for women in fertile age.

scholarly journals High risk of thrombosis in patients homozygous for factor V Leiden (activated protein C resistance) [see comments]

Blood ◽  
1995 ◽  
Vol 85 (6) ◽  
pp. 1504-1508 ◽  
Author(s):  
FR Rosendaal ◽  
T Koster ◽  
JP Vandenbroucke ◽  
PH Reitsma
Keyword(s):  
Venous Thrombosis ◽  
Protein C ◽  
Absolute Risk ◽  
Thrombotic Event ◽  
Activated Protein C ◽  
Factor V Leiden ◽  
Coagulation Factor ◽  
Factor V ◽  
Increased Risk ◽  
The Absolute

Resistance to activated protein C (APC) is a common inherited risk factor for venous thrombosis, which is associated with a mutation in coagulation factor V (factor V Leiden). We investigated the risk of venous thrombosis in individuals homozygous for this abnormality. We determined the factor V Leiden genotype in 471 consecutive patients aged less than 70 years with a first objectively confirmed deep-vein thrombosis and in 474 healthy controls. We found 85 heterozygous and seven homozygous individuals among the cases with thrombosis and 14 heterozygous individuals among the control subjects. The expected number of homozygous individuals among the controls was calculated from Hardy-Weinberg equilibrium and estimated at 0.107 (allele frequency, 1.5%). Whereas the relative risk was increased sevenfold for heterozygous individuals, it was increased 80-fold for homozygous individuals. These patients experienced their thrombosis at a much younger age (31 v 44 years). The homozygous individuals were predominantly women, most likely due to the effect of oral contraceptives. Because of the increased risk of thrombosis with age, the absolute risk becomes most pronounced in older patients, both for heterozygous and homozygous individuals. For the homozygous individuals, the absolute risk may become several percentage points per year. This implies that most individuals homozygous for factor V Leiden will experience at least one thrombotic event in their lifetime.

Risk of Pregnancy-related Venous Thrombosis in Carriers of Severe Inherited Thrombophilia

2001 ◽  
Vol 86 (09) ◽  
pp. 800-803 ◽  
Author(s):  
Cristina Legnani ◽  
Paolo Bucciarelli ◽  
Elvira Grandone ◽  
Valerio De Stefano ◽  
Pier Mannuccio Mannucci ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Gene Mutations ◽  
Factor V Leiden ◽  
Study Cohort ◽  
Factor V ◽  
Thrombotic Risk ◽  
Increased Risk ◽  
Prothrombin Gene ◽  
Heterozygous Carriers ◽  
Anticoagulant Prophylaxis

SummaryHomozygous carriers of factor V Leiden have an approximately 80-fold increased risk of venous thrombosis. Also double heterozygous carriers of both the factor V Leiden and the prothrombin gene mutations are at high thrombotic risk. The magnitude of the risk of venous thrombosis in pregnant women with the two severe thrombophilic conditions has not been estimated so far. We performed a multicenter retrospective family study in women with homozygous factor V Leiden, double heterozygous factor V Leiden and the prothrombin gene mutation, and women with normal coagulation. Only relatives of index patients with thrombosis formed the study cohort. Fifteen homozygous and 39 double heterozygous women were compared to 182 women with normal coagulation. Venous thrombosis occurred in 3 of 19, 2 of 50 and 1 of 221 pregnancies, respectively. One thrombotic episode occurred in the third trimester, the remaining 5 in the postpartum. The prevalence of venous thrombosis was 15.8% (95% CI 3.4-39.6) for homozygotes, 4.0% (95% CI 0.5-13.7) for double heterozygotes and 0.5% for women with normal coagulation. The relative risk of pregnancy-related venous thrombosis was 41.3 (95% CI 4.1-419.7) for homozygous and 9.2 (95% CI 0.8-103.2) for double heterozygous carriers. In conclusion, homozygous carriers of factor V Leiden and, to a lesser extent, double heterozygous carriers of factor V Leiden and of the prothrombin mutation have an increased risk of venous thrombosis during pregnancy, particularly high during the postpartum period. On the basis of these findings we recommend that these women receive anticoagulant prophylaxis at least in the postpartum, that should perhaps be extended to the whole pregnancy in homozygous carriers.

Co-inheritance of the 20210A Allele of the Prothrombin Gene Increases the Risk of Thrombosis in Subjects with Familial Thrombophilia

1997 ◽  
Vol 78 (06) ◽  
pp. 1426-1429 ◽  
Author(s):  
M Makris ◽  
F E Preston ◽  
N J Beauchamp ◽  
P C Cooper ◽  
M E Daly ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Protein C ◽  
Factor V Leiden ◽  
Protein S ◽  
Factor V ◽  
Protein C Deficiency ◽  
Antithrombin Deficiency ◽  
Control Subjects ◽  
Increased Risk ◽  
Venous Thromboembolic

SummaryThe presence of the 20210A allele of the prothrombin (PT) gene has recently been shown to be a risk factor for venous thromboembolism. This is probably mediated through increased plasma prothrombin levels. The aim of this study was to compare the prevalence of the prothrombin 20210A allele in control subjects and in subjects with recognised thrombophilia and to establish whether the additional inheritance of the PT 20210A allele is associated with an increased risk of venous thromboembolism. 101 subjects with a history of venous thromboembolism and diagnosed as having either factor V Leiden (R506Q) or heritable deficiencies of protein C, protein S or antithrombin were studied. The prevalence of the PT 20210A allele in this group was compared with the results obtained for 150 control subjects. In addition, the relationships were examined between genetic status and the number of documented thromboembolic episodes, and between plasma prothrombin levels and possession of the PT 20210A allele. 8 (7.9%) of the 101 patients were also heterozygous for the PT 20210A allele. This compares with 0.7% in the control subjects (p = 0.005). After exclusion of patients on warfarin, the mean plasma prothrombin of 113 subjects without 20210A was 1.09 U/ml, as compared with 1.32 U/ml in 8 with the allele (p = 0.0002). Among the 101 patients with either factor V Leiden, protein S deficiency, protein C deficiency or antithrombin deficiency, the age adjusted mean (SD) number of venous thromboembolic episodes at diagnosis was 3.7 (1.5) in those with the PT 20210A allele, as compared with 1.9 (1.1) in those without (p = 0.0001). We have demonstrated that the prevalence of the PT 20210A allele is significantly greater in subjects with venous thrombosis and characterised heritable thrombophilia than in normal control subjects and that the additional inheritance of PT 20210A is associated with an increased risk of venous thromboembolism. We have also confirmed that plasma prothrombin levels are significantly greater in subjects possessing the PT 20210A compared with those who do not.

A Reduced Sensitivity for Activated Protein C in the Absence of Factor V Leiden Increases the Risk of Venous Thrombosis

Blood ◽  
1999 ◽  
Vol 93 (4) ◽  
pp. 1271-1276 ◽  
Author(s):  
Marieke C.H. de Visser ◽  
Frits R. Rosendaal ◽  
Rogier M. Bertina
Keyword(s):  
Risk Factor ◽  
Confidence Interval ◽  
Venous Thrombosis ◽  
Protein C ◽  
Activated Protein C ◽  
Factor V Leiden ◽  
Factor V ◽  
Factor V Leiden Mutation ◽  
Apc Resistance ◽  
Increased Risk

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.

The HR2 Haplotype of Factor V: Effects on Factor V Levels, Normalized Activated Protein C Sensitivity Ratios and the Risk of Venous Thrombosis

2000 ◽  
Vol 83 (04) ◽  
pp. 577-582 ◽  
Author(s):  
Joan Guasch ◽  
Pieter Kamphuisen ◽  
Hans Vos ◽  
Frits Rosendaal ◽  
Rogier Bertina ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Protein C ◽  
Activated Protein C ◽  
Factor V Leiden ◽  
Compound Heterozygous ◽  
Factor V ◽  
Vein Thrombosis ◽  
Increased Risk ◽  
V Antigen ◽  
Deep Vein

SummaryWe studied the HR2 haplotype of the factor V gene in a case-control study for venous thrombosis including 474 patients with a first deep-vein thrombosis and 474 age- and sex-matched healthy controls (Leiden Thrombophilia Study, LETS). We investigated both the original His1299Arg (A4070G) polymorphism and the Met385Thr (T1328C) polymorphism. This latter polymorphism, located in exon 8 (heavy chain), is always present in the HR2 haplotype, but also occurs on its own in a His1299 (wt) background. The HR2 haplotype was not associated with an increased risk of venous thrombosis (OR = 1.2, 95% confidence interval: 0.8-2.0). We did not find an association between the HR2 haplotype and a reduced sensitivity for activated protein C (APC) in non-carriers of factor V Leiden (FVL). However, in compound heterozygous FVL/HR2 carriers the sensitivity for APC was reduced. The HR2 haplotype was also associated with reduced factor V antigen levels in both patients and controls. Sequence analysis of the promoter region of factor V in HR2 homozygotes did not reveal any sequence variations that could explain the reduced FV levels. Our results show that the HR2 haplotype is not associated with an increased risk of venous thrombosis or with a reduced sensitivity for APC in non-FVL carriers. However, the HR2 haplotype is associated with a reduced sensitivity for APC in carriers of FVL and with reduced factor V antigen levels.

scholarly journals Increased Risk of Venous Thrombosis in Oral-Contraceptive Users Who Are Carriers of Factor V Leiden Mutation

1995 ◽  
Vol 50 (7) ◽  
pp. 531-533
Author(s):  
Jan P. Vandenbroucke ◽  
Ted Koster ◽  
Ernest Briet ◽  
Pieter H. Reitsma ◽  
Rogier M. Bertina ◽  
...  
Keyword(s):  
Oral Contraceptive ◽  
Venous Thrombosis ◽  
Factor V Leiden ◽  
Factor V ◽  
Factor V Leiden Mutation ◽  
Increased Risk
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