Factor V Leiden is...

Factor V Leiden is...

• A. Most common inherited cause of hypercoagulability
• B. A vitamin K–dependent deficiency
• C. An acquired bleeding disorder
• D. A disorder that exclusively increases bleeding risk

Answer: (A)

Factor V Leiden is an inherited mutation in the Factor V gene that makes Factor V resistant to inactivation by activated protein C. This resistance impairs the body’s natural anticoagulation, tipping the balance toward clot formation and creating a prothrombotic state. It is the most common inherited cause of hypercoagulability, especially among people of European descent, and it’s passed down in an autosomal dominant pattern with variable expression—so carriers have a higher risk of venous clots, particularly with triggers like surgery, immobilization, pregnancy, or estrogen use. It is not a vitamin K–dependent deficiency, which would lead to bleeding, nor is it an acquired bleeding disorder. It does not only increase bleeding risk; it predominantly increases the risk of thrombosis, such as deep vein thrombosis and pulmonary embolism. Lab testing can show activated protein C resistance, and genetic testing can identify the Factor V Leiden mutation.

Factor V Leiden is an inherited mutation in the Factor V gene that makes Factor V resistant to inactivation by activated protein C. This resistance impairs the body’s natural anticoagulation, tipping the balance toward clot formation and creating a prothrombotic state. It is the most common inherited cause of hypercoagulability, especially among people of European descent, and it’s passed down in an autosomal dominant pattern with variable expression—so carriers have a higher risk of venous clots, particularly with triggers like surgery, immobilization, pregnancy, or estrogen use. It is not a vitamin K–dependent deficiency, which would lead to bleeding, nor is it an acquired bleeding disorder. It does not only increase bleeding risk; it predominantly increases the risk of thrombosis, such as deep vein thrombosis and pulmonary embolism. Lab testing can show activated protein C resistance, and genetic testing can identify the Factor V Leiden mutation.