This gene encodes an essential cofactor of the blood coagulation cascade. This factor circulates in plasma, and is converted to the active form by the release of the activation peptide by thrombin during coagulation. This generates a heavy chain and a light chain which are held together by calcium ions. The activated protein is a cofactor that participates with activated coagulation factor X to activate prothrombin to thrombin. Defects in this gene result in either an autosomal recessive hemorrhagic diathesis or an autosomal dominant form of thrombophilia, which is known as activated protein C resistance. [provided by RefSeq, Oct 2008]

factor V: Central regulator of hemostasis. It serves as a critical cofactor for the prothrombinase activity of factor Xa that results in the activation of prothrombin to thrombin. Defects in F5 are the cause of factor V deficiency (FA5D); also known as Owren parahemophilia. It is an hemorrhagic diastesis. Defects in F5 are the cause of thrombophilia due to activated protein C resistance (THPH2). THPH2 is a hemostatic disorder due to defective degradation of factor Va by activated protein C. It is characterized by a poor anticoagulant response to activated protein C resulting in tendency to thrombosis. Defects in F5 are a cause of susceptibility to Budd- Chiari syndrome (BDCHS). A syndrome caused by obstruction of hepatic venous outflow involving either the hepatic veins or the terminal segment of the inferior vena cava. Obstructions are generally caused by thrombosis and lead to hepatic congestion and ischemic necrosis. Clinical manifestations observed in the majority of patients include hepatomegaly, right upper quadrant pain and abdominal ascites. Budd-Chiari syndrome is associated with a combination of disease states including primary myeloproliferative syndromes and thrombophilia due to factor V Leiden, protein C deficiency and antithrombin III deficiency. Budd-Chiari syndrome is a rare but typical complication in patients with polycythemia vera. Defects in F5 may be a cause of susceptibility to ischemic stroke (ISCHSTR); also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors. Defects in F5 are associated with susceptibility to pregnancy loss, recurrent, type 1 (RPRGL1). RPRGL1 is a common complication of pregnancy, resulting in spontaneous abortion before the fetus has reached viability. The term includes all miscarriages from the time of conception until 24 weeks of gestation. Recurrent pregnancy loss is defined as 3 or more consecutive spontaneous abortions. Belongs to the multicopper oxidase family.

Protein type: Protease; Secreted, signal peptide; Secreted

Chromosomal Location of Human Ortholog: 1q23

Cellular Component: Golgi apparatus; extracellular space; membrane; endoplasmic reticulum; extracellular region; plasma membrane; vesicle

Molecular Function: protein binding; copper ion binding; serine-type endopeptidase activity

Biological Process: platelet activation; platelet degranulation; blood circulation; proteolysis; blood coagulation

Disease: Thrombophilia Due To Activated Protein C Resistance; Budd-chiari Syndrome; Stroke, Ischemic; Pregnancy Loss, Recurrent, Susceptibility To, 1; Factor V Deficiency