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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 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 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 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 & Diagnosis
Symptoms include:
• Bleeding into the skin
• Excessive bruising with minor injuries
• Nose bleeds o 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.
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