Coags

Factor V Leiden

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Factor V Leiden, Factor 5 Leiden, Activated Protein C resistance, APC Resistance

  • Epidemiology
  1. Responsible for 20-50% of Hypercoagulable patients
  2. Incidence of Autosomal Dominant genetic defect
    1. Europeans: 15%
    2. North America: 3-5%
  • Risks
  1. Heterozygote: 5-10 times the risk of thrombosis
  2. Homozygote: 50-100 times the risk of thrombosis
  • Pathophysiology
  1. Factor V is a Cofactor for Factor X
  2. Defect prevents Factor V degradation by Protein C
  • Labs
  1. Activated Protein C (APC) resistance
    1. Can not be anticoagulated when this lab run
  2. PCR for Factor V Leiden
    1. Responsible for 95% of APC Resistance
    2. Does NOT require that patient be off Anticoagulation