II. Epidemiology

  1. Most common inherited Thrombophilia in the United States
    1. HeterozygousPrevalence: 3 to 7% (U.S.)
    2. Responsible for 20-50% of Hypercoagulable patients
  2. Incidence of Autosomal Dominant genetic defect
    1. Europeans: 15%
    2. North America: 3-5%
  3. Ethnicity
    1. Most common in white patients
    2. African Americans represent <1% of cases

III. Pathophysiology

  1. Factor V is a Cofactor for Factor X
  2. Defect prevents Factor V (and Va) degradation by Protein C
  3. Originally named for a poor Anticoagulant response to activated Protein C (APC)

IV. Labs

  1. Activated Protein C (APC) resistance
    1. Can not be anticoagulated when this lab is run
    2. Tests for Anticoagulant response to activated Protein C (APC)
      1. Activated form of Factor V (Factor Va) is more slowly degraded by activated Protein C
      2. Although Factor V Leiden is the most common cause of APC Resistance, it is not the only cause
  2. PCR for Factor V Leiden
    1. Responsible for 95% of APC Resistance
    2. Does NOT require that patient be off Anticoagulation
    3. Patients may be found to be either Heterozygous or Homozygous for Factor V

V. Complications

  1. General
    1. Heterozygote: 5-10 times the risk of thrombosis
    2. Homozygote: 50-100 times the risk of thrombosis
    3. Factor V Leiden is found in 21% of DVT patients (contrast with 5% of healthy patients)
      1. Also found to be associated with more extensive DVTs of larger veins
      2. Arsov (2006) Croat Med 47(3): 433-9 [PubMed]
  2. Deep Vein Thrombosis
  3. Pulmonary Embolism
  4. Myocardial Infarction

VII. References

  1. Jean-Louis and Sethuraman (2023) Crit Dec Emerg Med 37(7): 4-11

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Related Studies

Ontology: Factor V Leiden mutation (C0584960)

Definition (NCI) An abnormality that refers to mutation of factor V Leiden, which is a variant of human factor V. It results in thrombophilia, deep vein thrombosis, and a slightly increased risk of miscarriage.
Concepts Disease or Syndrome (T047)
ICD10 D68.51
SnomedCT 307091009
Italian Mutazione del Fattore V Leiden
Japanese 第V因子ライデン変異, ダイ5インシライデンヘンイ
English factor V Leiden mutation, factor V Leiden mutation (diagnosis), factor leiden mutation v, factor v leiden mutation, leiden mutation factor v, Factor V Leiden Mutation, Factor V Leiden mutation, Factor V Leiden, Factor V Leiden mutation (disorder)
Czech Leidenská mutace faktoru V
Hungarian Faktor V Leiden mutatio
Spanish mutación del factor V Leiden (trastorno), mutación del factor V Leiden, Factor V de Leiden
Portuguese Mutação do factor V de Leiden
Dutch factor V Leiden mutatie
French Mutation du facteur V de Leiden
German Leiden-Mutation

Ontology: Activated Protein C Resistance (C0600433)

Definition (MSH) A hemostatic disorder characterized by a poor anticoagulant response to activated protein C (APC). The activated form of Factor V (Factor Va) is more slowly degraded by activated protein C. Factor V Leiden mutation (R506Q) is the most common cause of APC resistance.
Concepts Disease or Syndrome (T047)
MSH D020016
ICD10 D68.51
SnomedCT 421527008
LNC LP18494-2, MTHU004273
English Activated protein C resistance, Resistance to activated protein C due to Factor V Leiden (disorder), Resistance to activated protein C due to Factor V Leiden, Resistance to activated protein C due to Factor V R506Q, Activated Protein C Resistance, APC Resistance, Resistance, APC, activated protein C resistance, activated protein C resistance (diagnosis), Resistance to activated protein C, Activated Protein C Resistance [Disease/Finding], activated protein c resistance, apc resistance
Japanese 活性化プロテインC抵抗性, カッセイカプロテインCテイコウセイ, APCレジスタンス, 活性化プロテインCレジスタンス, 活性化プロテインC抵抗性
Swedish Aktiverat protein C-resistens
Czech FVL - faktor V Leiden, rezistence k aktivovanému proteinu C, APC rezistence, faktor V - leidenská mutace, Rezistence na aktivovaný protein C
Finnish APC-resistenssi
Russian BELKA C AKTIVIROVANNOGO USTOICHIVOST', PROTEINA C AKTIVIROVANNOGO REZISTENTNOST', БЕЛКА C АКТИВИРОВАННОГО УСТОЙЧИВОСТЬ, ПРОТЕИНА C АКТИВИРОВАННОГО РЕЗИСТЕНТНОСТЬ
Italian APC resistenza, Resistenza alla proteina C attivata
Spanish resistencia a proteína C activada debida a Factor V de Leiden (trastorno), resistencia a la proteina C activada debido al Factor V de Leiden (trastorno), resistencia a la proteina C activada debido al Factor V de Leiden, resistencia a proteína C activada debida a Factor V de Leiden, Resistencia a la Proteína C Activada, Resistencia a la APC, Resistencia a la PCA, RPCA, Resistencia a la proteína C activada
Polish Oporność APC, Oporność na aktywne białko C
Hungarian aktivált protein-C resistentia
French RPCa (Résistance à la PCa), RPCa (Résistance à la Protéine C activée), Résistance à la protéine C activée
Norwegian Faktor V-Leiden-mutasjon, Aktivert protein C-resistens, Resistens mot aktivert protein C
Portuguese RPCA, Resistência a proteína C activada, Resistência à APC, Resistência à Proteína C Ativada
Dutch geactiveerde eiwit C weerstand, APC-resistentie, Geactiveerde-proteïne-C-resistentie, Resistentie, geactiveerde-proteïne-C-
German Resistenz gegenueber aktiviertem Protein C, APC-Resistenz, Resistenz gegen aktiviertes Protein C

Ontology: Factor V Leiden heterozygote (C1168517)

Concepts Disease or Syndrome (T047)
Dutch factor V Leiden heterozygoot
French Facteur V de Leiden hétérozygote
German Faktor-V-Leiden-Mutation heterozygot
Italian Eterozigote per Fattore V Leiden
Portuguese Factor V Leiden heterozigótico
Spanish Factor V de Leiden heterocigoto
Japanese 第V因子ライデン異型接合体, ダイ5インシライデンイケイセツゴウタイ
Czech Heterozygotní forma Leidenské mutace faktoru V
Hungarian Faktor V LEIDEN ((heterozigóta))
English Factor V Leiden heterozygote

Ontology: Factor V Leiden homozygote (C1168518)

Concepts Disease or Syndrome (T047)
Dutch factor V Leiden homozygoot
French Facteur V de Leiden homozygote
German Faktor-V-Leiden-Mutation homozygot
Italian Omozigote per Fattore V Leiden
Portuguese Factor V Leiden homozigótoco
Spanish Factor V de Leiden homocigoto
Japanese 第V因子ライデン同型接合体, ダイ5インシライデンドウケイセツゴウタイ
Czech Homozygotní forma Leidenské mutace faktoru V
Hungarian Faktor V LEIDEN ((homozygota))
English Factor V Leiden homozygote