eMedicine Specialties > Hematology > Coagulation, Hemostasis, and Disorders
Factor V
Updated: Dec 18, 2007
Introduction
Background
Isolated factor V deficiency is a rare inherited coagulopathy. Factor V deficiency is also known as Owren disease or parahemophilia. Dr Paul Owren identified this defect in Norway in 1943. Using relatively primitive technology, he was able to deduce the existence of a fifth component required for fibrin formation, which he named factor V, thus beginning the era of Roman numerology for coagulation factors. Dr Owren's work defined factor V as the activity in normal plasma that corrected the prothrombin time (PT) of the plasma in a patient with factor V deficiency. Factor V deficiency has been called parahemophilia since hemarthrosis can occur with severe deficiencies and with increased bleeding time.
Pathophysiology
Factor V is an essential component in the blood coagulation cascade. Factor V is synthesized in the liver and possibly in megakaryocytes. Factor V circulates in an inactive form. During coagulation, factor V is converted to the active cofactor, factor Va, via limited proteolysis by the serine protease a-thrombin. Factor Va and activated factor Xa form the prothrombinase complex. The prothrombinase complex is responsible for the rapid conversion of the zymogen prothrombin to the active serine protease a-thrombin.
Factor V deficiency is a rare condition and is associated with an abnormal factor V plasma level.
Acquired inhibitor against coagulation factor V is a rare clinical condition with hemorrhagic complications of varying severity. The addition of normal plasma cannot correct the prolonged PT and activated partial thromboplastin time (aPTT). Factor V inhibitors can occur after surgery, childbirth, autoimmune diseases, and with certain neoplasms.
Thrombin cleaves fibrinogen to form fibrin, leading to the ultimate step in coagulation, the formation of a fibrin clot.
Factor V Leiden is a completely different inherited disorder in which factor V is mutated in a specific gene, leading to hypercoagulable status. The mutation is very common, occurring in 5% of the US population. Factor V activity levels in patients with factor V Leiden are normal.
Frequency
International
Only 150 cases of congenital factor V deficiency have been reported worldwide since 1943. Homozygous factor V deficiency is rare, occurring in approximately 1 per million population.
Mortality/Morbidity
The severity of factor V deficiency varies from bruising to lethal hemorrhage.
Race
No apparent racial predilection for factor V deficiency exists.
Sex
Factor V deficiency affects males and females with equal frequency.
Age
Factor V deficiency affects all ages. The age at presentation indirectly varies with the severity of disease.
Clinical
History
- Symptoms of factor V deficiency include the following:
- Bleeding into the skin
- Excessive bruising with minor injuries
- Nosebleeds
- Bleeding gums
- Excessive menstrual bleeding and prolonged or excessive loss of blood with surgery or trauma
- Bleeding in mucosal tracts (gastrointestinal, urinary)
- Hemarthrosis and flexion contracture
- Bleeding during delivery and postpartum
- Intracerebral hemorrhages
- Pulmonary hemorrhage
- The severity of bleeding symptoms is only partially related to the degree of factor V deficiency in plasma from immeasurable plasma levels.
Physical
The most common physical findings of factor V deficiency are ecchymoses, bleeding from mucosal surfaces, and pallor secondary to blood loss. Petechiae are uncommon because platelet numbers and function are not affected.
Causes
Factor V deficiency is caused by a large number of genetic abnormalities. The deficiency is a rare bleeding disorder whose genetic bases have been characterized in only a limited number of cases. The inheritance of factor V deficiency is autosomal recessive, with varying expressivity in the heterozygote; however, other modes of inheritance have been described. Heterozygotes have lowered levels of factor V but probably never bleed abnormally.
Consanguinity has been observed in families with factor V deficiency, related to its autosomal recessive inheritance. Heterozygous deficiency states are generally unrecognized because of a lack of significant clotting time prolongation or bleeding risk.
More on Factor V |
 Overview: Factor V |
| Differential Diagnoses & Workup: Factor V |
| Treatment & Medication: Factor V |
| Follow-up: Factor V |
| Multimedia: Factor V |
| References |
| Next Page » |
References
Fu YX, Kaufman R, Rudolph AE, Collum SE, Blinder MA. Multimodality therapy of an acquired factor V inhibitor. Am J Hematol. Apr 1996;51(4):315-8. [Medline].
Girolami A, Scandellari R, Lombardi AM, Girolami B, Bortoletto E, Zanon E. Pregnancy and oral contraceptives in factor V deficiency: a study of 22 patients (five homozygotes and 17 heterozygotes) and review of the literature. Haemophilia. Jan 2005;11(1):26-30. [Medline].
Ichikawa H. Successful total gastrectomy of gastric cancer in a congenital factor V deficient patient [in Japanese]. Nippon Ronen Igakkai Zasshi. Mar 2000;37(3):245-9. [Medline].
Lak M, Sharifian R, Peyvandi F, Mannucci PM. Symptoms of inherited factor V deficiency in 35 Iranian patients. Br J Haematol. Dec 1998;103(4):1067-9. [Medline].
Lee GR, Foerster J, Greer J, et al, eds. Wintrobe's Clinical Hematology. Vol 2. 10th ed. Baltimore, Md: Lippincott, Williams & Wilkins; 1999:1710-12.
Mann KG, Kalafatis M. Factor V: a combination of Dr Jekyll and Mr Hyde. Blood. Jan 1 2003;101(1):20-30. [Medline].
Mitterstieler G, Muller W, Geir W. Congenital factor V deficiency. A family study. Scand J Haematol. Jul 1978;21(1):9-13. [Medline].
Owren P. Parahaemophilia: haemorrhagic diathesis due to absence of a previously unknown clotting factor. Lancet. 1947;Vol I:446-8.
Sacco S, Dragani A, Davi G, Carolei A. Four recurrent intracerebral haemorrhages. Cerebrovasc Dis. 2003;16(4):435-6. [Medline].
Satoh H, Yamashita YT, Ohtsuka M, Sekizawa K, Hasegawa Y. Pulmonary hemorrhage in factor V deficiency. Can Respir J. Jul-Aug 1999;6(4):320. [Medline].
Song JW, Um MR, Ahn HS, Hong CY. A case of congenital factor V deficiency. J Korean Med Sci. Sep 1987;2(3):179-82. [Medline].
Totan M, Albayrak D. Intracranial haemorrhage due to factor V deficiency. Acta Paediatr. Mar 1999;88(3):342-3. [Medline].
Tracy PB, Mann KG. Abnormal formation of the prothrombinase complex: factor V deficiency and related disorders. Hum Pathol. Feb 1987;18(2):162-9. [Medline].
Yokoyama T, Tatemoto Y, Osaki T. Hemostatic treatment after tooth extraction in a patient with factor V deficiency. Oral Dis. Sep 1997;3(3):196-8. [Medline].
Yotsumoto G, Masuda H, Toyokawa K, Iguro Y, Kinjo T, Sakata R. Off-pump coronary artery bypass grafting in a patient with congenital factor V deficiency: report of a case. Surg Today. 2005;35(2):142-4. [Medline].
Zehnder JL, Hiraki DD, Jones CD, Gross N, Grumet FC. Familial coagulation factor V deficiency caused by a novel 4 base pair insertion in the factor V gene: factor V Stanford. Thromb Haemost. Sep 1999;82(3):1097-9. [Medline].
Further Reading
Keywords
factor V deficiency, FV, Owren disease, Owren's disease, accelerator globulin deficiency, hereditary factor V deficiency disease, proaccelerin deficiency, AC globulin deficiency, hereditary hypoproaccelerinemia, labile factor deficiency, hemophilia, parahemophilia, anticoagulation, coagulopathy anticoagulant, coagulation factors, hemostatic pathway, haemostatic pathway, coagulation pathway, acquired factor V inhibitor, von Willebrand factor, von Willebrand's factor, vWF, von Willebrand disease, von Willebrand's disease, vWD, coagulation factor V, thrombin, prothrombinase complex, platelet activation, platelet factor V, prothrombinase function, prothrombin time, PT, activated partial thromboplastin time, aPTT, partial thromboplastin time, PTT, factor IX, FIX, factor VIII, FVIII, bleeding disorder
