Factor V Gene Mutation Is a Risk Factor for Cerebral Venous Thrombosis

1996 ◽  
Vol 75 (03) ◽  
pp. 393-394 ◽  
Author(s):  
I Martinelli ◽  
G Landi ◽  
G Merati ◽  
R Cella ◽  
A Tosetto ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cerebral Venous Thrombosis ◽  
Protein C ◽  
Dna Analysis ◽  
Protein S ◽  
Factor V ◽  
Antithrombin Deficiency ◽  
Apc Resistance ◽  
Factor V Gene ◽  
V Gene

SummaryTo evaluate the association between coagulation defects and cerebral venous thrombosis, a case-control study was conducted in 25 patients who had no autoimmune, neoplastic or infectious disease and 75 healthy individuals. There were no patients with deficiency of protein C or protein S. Four had resistance to activated protein C (APC) and one had APC resistance associated with antithrombin deficiency. APC resistance was investigated by DNA analysis, and diagnosed by the presence of a point mutation in the factor V gene, which predicts replacement of Arg506 with Gin at one of the two APC cleavage sites in activated factor V. The prevalence of APC resistance was 20% in patients and 2.7% in controls. This difference was statistically significant (p = 0.01) and the odds ratio was 9.1. A circumstantial factor predisposing to cerebral venous thrombosis (such as oral contraceptive intake, pregnancy, puerperium, trauma or prolonged immobilization) was reported in 72% of cases. In conclusion, APC resistance is the most frequent coagulation abnormality associated with cerebral venous thrombosis.

Elevated Levels of Prothrombin Activation Fragment 1+2 in Plasma from Patients with Heterozygous Arg506 to Gin Mutation in the Factor V Gene (APC-Resistance) and/or Inherited Protein S Deficiency

1996 ◽  
Vol 75 (02) ◽  
pp. 270-274 ◽  
Author(s):  
Benget Zöller ◽  
Johan Holm ◽  
Peter Svensson ◽  
Björn Dahlbäck
Keyword(s):  
Plasma Concentration ◽  
Protein C ◽  
Protein S ◽  
Factor V ◽  
Protein S Deficiency ◽  
Apc Resistance ◽  
S Deficiency ◽  
Increased Risk ◽  
Factor V Gene ◽  
V Gene

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.

scholarly journals A Factor V Genetic Component Differing From Factor V R506Q Contributes to the Activated Protein C Resistance Phenotype

Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1552-1557 ◽  
Author(s):  
F. Bernardi ◽  
E.M. Faioni ◽  
E. Castoldi ◽  
B. Lunghi ◽  
G. Castaman ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Protein C ◽  
Activated Protein C ◽  
Functional Assay ◽  
Factor V ◽  
Resistance Phenotype ◽  
Apc Resistance ◽  
Genetic Components ◽  
Factor V Gene ◽  
V Gene

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.

scholarly journals A Factor V Genetic Component Differing From Factor V R506Q Contributes to the Activated Protein C Resistance Phenotype

Blood ◽  
1997 ◽  
Vol 90 (4) ◽  
pp. 1552-1557 ◽  
Author(s):  
F. Bernardi ◽  
E.M. Faioni ◽  
E. Castoldi ◽  
B. Lunghi ◽  
G. Castaman ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Protein C ◽  
Activated Protein C ◽  
Functional Assay ◽  
Factor V ◽  
Resistance Phenotype ◽  
Apc Resistance ◽  
Genetic Components ◽  
Factor V Gene ◽  
V Gene

Factor 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.

Homozygous APC-resistance Combined with Inherited Type I Protein S Deficiency in a Young Boy with Severe Thrombotic Disease

1995 ◽  
Vol 73 (05) ◽  
pp. 743-745 ◽  
Author(s):  
Bengt Zöller ◽  
Xuhua He ◽  
Björn Dahlbäck
Keyword(s):  
Activated Protein C ◽  
Protein S ◽  
Type I ◽  
Factor V ◽  
Protein S Deficiency ◽  
Complete Evaluation ◽  
Apc Resistance ◽  
S Deficiency ◽  
Factor V Gene ◽  
V Gene

SummaryInherited resistance to activated protein C (APC) is a frequent cause of familial thrombosis. It is associated with a factor V gene point mutation replacing arginine506 in the APC-cleavage site with a glutamine. Thrombotic events are rare during childhood even in patients with homozygous APC-resistance. We now wish to report on a case of severe venous thrombosis, in a 10-year-old boy. He was found to have pronounced APC-resistance due to homozygous factor V gene mutation in combination with inherited type I protein S deficiency. The two traits were independently inherited in the family. The APC-resistance was partially corrected by adding factor V, whereas added protein S was without effect. This is the first reported case of homozygous APC-resistance combined with another inherited prothrombotic disorder. It illustrates how multiple genetic defects may provoke thrombosis at young age and emphasizes the need of complete evaluation of thrombotic patients in order to determine whether multiple risk factors exist.

Myocardial infarction under the age of 36: prevalence of thrombophilic disorders

2003 ◽  
Vol 90 (08) ◽  
pp. 272-279 ◽  
Author(s):  
Chrusula Belesi ◽  
Helen Manioudaki ◽  
Vassilis Chatziioakimidis ◽  
Vassiliki Fakitsa ◽  
Loukas Sinos ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Protein C ◽  
Antithrombin Iii ◽  
Protein S ◽  
Factor V ◽  
C Protein ◽  
G20210a Mutation ◽  
Factor V Gene ◽  
Prothrombin Gene ◽  
V Gene

SummaryIt has been suggested that thrombotic tendency increases the risk of myocardial infarction (MI). To investigate the association between the risk of MI at a young age and genetic thrombogenic disorders (G20210A mutation in the prothrombin gene, G1691A mutation in the factor V gene and deficiencies of protein C, protein S and antithrombin III) we conducted a case-control study among 70 survivors of MI who had experienced the event before the age of 36 and 260 healthy subjects. The G20210A mutation in the prothrombin gene was found more often in young patients with MI than among controls (11.4 versus 3.1%). The odds ratio (OR) for MI for carriers versus non-carriers was 4 (95% confidence interval [CI], 1.5 to 11.3). The adjusted OR for major cardiovascular risk factors (smoking, hypecholesterolaemia, diabetes mellitus, hypertension and obesity) was 4.3 (95% CI,1.3 to 14). The simultaneous presence of both G20210A mutation in the prothrombin gene and smoking further increased the risk of MI compared with nonsmokers and non-carriers (OR, 58; 95% CI, 11.4-294). The G1691A mutation in factor V gene was not associated with an increased relative risk for MI (OR, 0.87; 95% CI, 0.26 to 2.5). Finally, there was no significant difference in the prevalence of deficiencies of protein C, protein S and antithrombin III between cases and controls. In conclusion, our data indicate that the G20210A mutation in the prothrombin gene was the only genetic prothrombotic risk factor associated with the risk of developing MI under the age of 36 years.

State-of-the-Art Review: Activated Protein C Resistance: Clinical Implications

1997 ◽  
Vol 3 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Bengt Zöller ◽  
Andreas Hillarp ◽  
Björn Dahlbäck
Keyword(s):  
Risk Factors ◽  
Venous Thrombosis ◽  
Protein C ◽  
Activated Protein C ◽  
Protein S ◽  
Factor V ◽  
Thrombotic Risk ◽  
Western Countries ◽  
Apc Resistance ◽  
Increased Risk

The discovery of inherited resistance to activated protein C (APC) as a major risk factor for venous thrombosis has dramatically improved our understanding of the pathogenesis of venous thrombosis. In a majority of cases, APC resistance is associated with a single point mutation in the factor V gene (FV) that results in substitution of arginine, R, at position 506 by glutamine, Q. (FV:Q506). The mutation renders factor Va partially resistant to degradation by APC. A functional APC resistance test, which includes predilution of the patient plasma with factor V-deficient plasma, is found to be 100% sensitive and specific for the presence of FV:Q506 and is useful as a screening assay. Carriers of the FV:Q506 allele have increased thrombin generation, resulting in hypercoagulability and a lifelong increased risk of venous thrombosis. In Western countries, APC resistance due to the FV mutation is present in 20-60% of thrombosis patients and in 1-15% of healthy controls, whereas the mutation is virtually absent from ethnic groups other than Caucasians. This may explain the high incidence of venous thrombosis in Western countries. The thrombotic risk in APC-resistant individuals may be further increased by other genetic defects, e.g., protein C or protein S deficiency, and by exposure to circumstantial risk factors, e.g., oral contraceptives, pregnancy, immobilization, and surgery. The question is thus raised as to whether general screening for APC resistance before circumstantial risk factors occur is warranted in Western countries. Key Words: Factor V—APC resistance-Protein C-Protein S—Thrombosis—Mutation.

Sign in / Sign up

Export Citation Format

Share Document