Search results
Results from the WOW.Com Content Network
The minor ("type 2") thrombophilias are much more common. Factor V Leiden is present in 5% of the population of Northern European descent, but much rarer in those of Asian or African extraction. In people with thrombosis, 10% have factor V Leiden. In those who are referred for thrombophilia testing, 30–50% have the defect.
Pathophysiology of factor V Leiden gene mutation. Factor V Leiden is an autosomal dominant genetic condition that exhibits incomplete penetrance, i.e. not every person who has the mutation develops the disease. The condition results in a factor V variant that cannot be as easily degraded by activated protein C.
In fact, Factor V Leiden is the most common cause of inherited thrombosis. [26] Heterozygous factor V Leiden is present in approximately 5% of the white population in the United States and homozygous factor V Leiden is found less than 1% of this population. [27]
Coagulation factor V (Factor V), also less commonly known as proaccelerin or labile factor, is a protein involved in coagulation, encoded, in humans, by F5 gene. [5] In contrast to most other coagulation factors, it is not enzymatically active but functions as a cofactor . [ 5 ]
The best known and most common hereditary form is Factor V Leiden, which is responsible for more than 95% of cases. [5] Other genetic causes include Factor V Cambridge (VThr306) and the factor V HR2 haplotype (A4070G mutation). [5] [6] Acquired forms of APC resistance occur in the presence of elevated Factor VIII concentrations.
Factor V Leiden is responsible for 8% of cases. [2] Other less common inherited disorders leading to the condition include factor II mutation (3%), protein C deficiency (5%), protein S deficiency (4%), and antithrombin III deficiency(1%). [2] [14] Budd–Chiari syndrome may be the presenting sign of these hypercoagulable disorders.
Occasionally, blood-thinning medication may be indicated to reduce the risk of clotting. [11] A 2005 article concluded that heterozygous carriers who take combined birth control pills are at a 15-fold increased risk of venous thromboembolism, [12] while carriers also heterozygous with factor V Leiden have an approximate 20-fold higher risk. [2]
The last category, alterations in the constitution of blood, [6] has numerous possible risk factors such as hyperviscosity, coagulation factor V Leiden mutation, coagulation factor II G2021A mutation, deficiency of antithrombin III, protein C or S deficiency, nephrotic syndrome, changes after severe trauma or burn, cancer, late pregnancy and ...