“Coagulation factor V” is the name of a protein that helps your blood clot when needed, like after an injury. Your F5 gene tells your body how to make this protein. People who have factor V Leiden get either one copy or, rarely, two copies of the changed gene from their parents. Having one copy of the changed gene slightly raises the risk of getting blood clots. Factor V, or proaccelerin, is a protein made in your liver that helps convert prothrombin into thrombin. This is an important step in the blood clotting process. If you don’t have enough factor V. Factor V is an essential blood-clotting protein that plays a supporting but critical role in normal coagulation. It is also known as Proaccelerin or Labile Factor. When Factor V levels or activity are reduced, the clotting process becomes inefficient, and bleeding may last longer than expected. Factor V (factor 5) is one of several special proteins in your blood that help it clot. They're called clotting factors. Once the bleeding stops, other proteins tell your clotting factors to. Coagulation factor V (Factor V), also less commonly known as proaccelerin or labile factor, is a protein involved in coagulation, encoded, in humans, by F5 gene. [5] An overview of symptoms, genetics, and treatments to help you understand factor V deficiency. Factor V (FV) deficiency was first described in a Norwegian patient in 1943 and reported by Dr. Paul Owren in 1947. Its incidence is about 1 in 1 million; fewer than 200 cases have been documented worldwide. We’ll be taking a deep dive into Factor V Leiden, exploring what it is, who is at risk, and how it can be treated. Our goal is to help demystify this condition and provide a comprehensive guide to living with Factor V Leiden. Healthcare professionals most often prescribe blood-thinning medicines to treat people who get blood clots. People who have the factor V Leiden gene change but who have not had blood clots don't need this medicine. People with factor V Leiden thrombophilia have a higher than average risk of developing a type of blood clot called a deep venous thrombosis (DVT). DVTs occur most often in the legs, although they can also occur in other parts of the body, including the brain, eyes, liver, and kidneys.