title: Activated protein C resistance and factor V Leiden: a review.
abstract: BACKGROUND
  Factor V Leiden (FVL) is the most common heritable cause of venous thrombosis. It is caused by a single nucleotide substitution resulting in an R506Q missense mutation, resulting in factor V resistance to activated protein C (APC) inactivation. Carriers of FVL have an increased susceptibility to venous thrombosis, which is further increased in the presence of other genetic or environmental risk factors.
  
  
  OBJECTIVE
  To review the biology, clinical findings, laboratory detection methods, and screening recommendations for patients with the FVL mutation.
  
  
  METHODS
  PubMed review of published literature and online information.
  
  
  CONCLUSIONS
  FVL remains an important heritable cause of hypercoagulability since its discovery more than 10 years ago. Clinical suspicion should be high in cases of unexplained venous thrombosis. APC resistance and FVL mutation can be diagnosed with high sensitivity and specificity with use of clotting time-based functional assays and genetic assays, respectively, allowing for evidence-guided clinical decision making regarding the benefit of long-term anticoagulation.
authors.affiliation: Department of Pathology, Brigham and Women's Hospital, Boston, Mass 02115, USA.
authors.forename: Adam
authors.initials: A
authors.lastname: Rosendorff
authors.forename: David M
authors.initials: DM
authors.lastname: Dorfman
mesh_terms: D020016:Activated Protein C Resistance / Q000175:diagnosis / Q000235:genetics* / Q000628:therapy; D000818:Animals; D004195:Disease Models, Animal; D005165:Factor V / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D051379:Mice; D017354:Point Mutation; D013923:Thromboembolism / Q000235:genetics / Q000473:pathology / Q000628:therapy; D020246:Venous Thrombosis / Q000235:genetics / Q000473:pathology / Q000628:therapy
chemical_list: C095381:factor V Leiden; D005165:Factor V