Factor V deficiency is an inherited bleeding disorder that is caused by a problem with factor V. Because the body produces less factor V than it should, or because the factor V is not working properly, the clotting reaction is blocked prematurely and the blood clot does not form.

Factor V deficiency is an autosomal recessive disorder, which means that both parents must carry the defective gene in order to pass it on to their child. It also means that the disorder affects both males and females. Factor V deficiency is very rare, but like all autosomal recessive disorders, it is found more frequently in areas of the world where marriage between close relatives is common.

Symptoms

The symptoms of factor V deficiency are generally mild. Some people may experience no symptoms at all. However, children with a severe deficiency of factor V may bleed very early. Some patients have experienced bleeding in the central nervous system (the brain and spinal cord) very early in life.

Common symptoms

• Nosebleeds (epistaxis)
• Easy bruising
• Heavy or prolonged menstrual bleeding (menorrhagia)
• Bleeding in the mouth, particularly after dental surgery or tooth extraction

Other reported symptoms

• Bleeding in the gut (gastrointestinal haemorrhage)
• Muscle bleeds
• Abnormal bleeding during or after injury, surgery, or childbirth

Rare symptoms

• Bleeding into joints (haemarthrosis)
• Bleeding in the central nervous system (the brain and spinal cord)

Diagnosis

Factor V deficiency is diagnosed by a variety of blood tests that should be performed by a specialist at a Comprehensive Care Centre. People with abnormal levels of factor V should also have their factor VIII levels checked to rule out combined factor V and factor VIII deficiency, which is a completely separate disorder.

Treatment

Treatment for factor V deficiency is usually only needed for severe bleeds or before surgery. Fresh Frozen Plasma (FFP) is the usual treatment because there is no concentrate containing only factor V. Platelet transfusions, which contain factor V, are also sometimes an option.

Excessive menstrual bleeding in women with factor V deficiency may be controlled with hormonal contraceptives (birth control pills) or antifibrinolytic drugs.