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Hypercoagulable Disorders
Problems with coagulation cascade regulation


  • Activated Protein C resistance (Factor V Leiden mutation) -- a mutation in the gene that makes the factor V protein. Factor V is activated normally, but it is resistant to degradation by activated Protein C, which regulates the clotting process.
  • Antithrombin (III) deficiency or dysfunction -- this is a factor that helps decrease the activity of the clotting process by inhibiting factors Xa, IXa, XIa, and thrombin. Inherited or acquired deficiency of antithrombin can lead to a clot formation.
  • Protein C deficiency or dysfunction -- Protein C helps regulate the speed of the coagulation cascade by degrading activated factors V and VIII.
  • Protein S deficiency or dysfunction -- Protein S is a cofactor with Protein C
  • Prothrombin 20210 mutation -- a mutation that results in an increased amount of thrombin (activated factor II) in the circulation, which is associated with an increased risk for venous blood clots.
  • Elevated factor VIII levels -- persistently elevated factor VIII levels that are not associated with inflammation or other acquired conditions but are associated with an increased thrombotic risk.
  • Acquired:

  • Antiphospholipid syndrome (lupus anticoagulant and anticardiolipin antibody)
  • Disseminated intravascular coagulation (DIC)
  • Bone marrow disorders such as myeloproliferative disorders
  • In very rare cases, antibodies to coagulation factors; most factor antibodies cause bleeding episodes, not clotting problems.
  • Systemic lupus erythematosus - an autoimmune disorder

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    This article last reviewed on May 23, 2007.
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