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HEMOPHILIA.ORG > BLEEDING DISORDERS INFO CENTER > TYPES >
FACTOR V DEFICIENCY


Factor V Deficiency
(Parahemophilia, Labile factor or Proaccelerin Deficiency)

What Is It?
Factor V deficiency is also known as Owren's disease or parahemophilia. This deficit was identified in Norway in 1943. Since then about 150 cases have been reported, occurring in both men and women. The exact frequency of this rare disorder is unknown, but is estimated to be one per 1 million.

The role of factor V is to accelerate the activity of thrombin. When levels of factor V are low, blood clotting is delayed or it progresses slowly. People with this deficiency may have occasional nosebleeds, excessive menstrual bleeding and bruising; although, many have no symptoms. The first sign of this condition may be bleeding following surgery.

In this disorder, bleeding ranges from mild to severe. The disease is similar to hemophilia, except that bleeding into joints is uncommon. Bleeding can occur almost anywhere in the body, and death from hemorrhage has occurred with this disorder. Excessive bleeding with menstrual periods and postpartum hemorrhage occurs frequently.

A family history of a bleeding disorder is a risk factor. Men and women are affected equally.

The probable outcome is good with proper diagnosis and treatment.

Inheritance Pattern
The disorder is not sex-linked as is hemophilia. It affects both males and females with equal frequency. It is autosomal recessive, which means that if the clotting defect is inherited from a parent, the child will be a genetic carrier of the condition, but may or may not have symptoms.

Several families with combined deficiencies of factors V and VIII have been reported.

Symptoms and Diagnosis
Symptoms include:
• bleeding into the skin
• excessive bruising with minor injuries
• nose bleeds
• bleeding of the gums
• excessive menstrual bleeding
• prolonged or excessive loss of blood with surgery or trauma

Diagnosing the deficiency involves tests and signs such as:
• factor V assay showing decreased activity
• slightly prolonged bleeding time (in some people)
• prolonged partial thromboplastin time
• prolonged prothrombin time

Treatments
There are no commercially available concentrates of factor V, so fresh plasma or fresh frozen plasma infusions are used to correct the deficiency temporarily and should be given daily during a bleeding episode. Other plasma is not given because factor V deteriorates very rapidly. The half-life of factor V is 24 hours.

This is an inherited disorder; there is no known prevention.

Complications
Dangerous hemorrhaging can occur if bleeding isn't controlled quickly. If platelets are used as a source of factor V, antiplatelet antibodies can be induced.

Disclaimer
The information contained on the NHF web site is provided for your general information only. NHF does not give medical advice or engage in the practice of medicine. NHF under no circumstances recommends particular treatment for specific individuals and in all cases recommends that you consult your physician or local treatment center before pursuing any course of treatment.
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