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HEMOPHILIA.ORG
> BLEEDING DISORDERS INFO CENTER > TYPES >
FACTOR II DEFICIENCY
Factor II Deficiency
(Prothrombin)
What Is It?
Prothrombin is a vitamin K-dependent proenzyme that functions in coagulation.
There are two types of this deficiency, a congenital version called hypoprothrombinemia,
and an acquired version called dyspothrombinemia.
A life-long bleeding disorder when congenital, factor II deficiency is extremely
rare. In fact, only 30 cases of this hereditary clotting factor defect have
been identified in the whole world.
Acquired factor II deficiency is more common. It results from vitamin K
deficiency, severe liver disease and therapeutic use of anticoagulant drugs.
Risk factors for vitamin K deficiency are prolonged use of antibiotics,
bile duct obstruction and intestinal malabsorption (inadequate absorption
of nutrients from the intestinal tract) disorders. Some newborns are born
with vitamin K deficiency.
If the deficiency is caused by liver disease, the outcome depends on control
of the liver problem. Vitamin K administration will correct vitamin K deficiency.
Either form may lead to severe bruising, excessive menstrual bleeding, postoperative
hemorrhage and occasional muscle bleeds.
Inheritance Pattern
A congenital factor II deficiency is a very rare inherited disorder that
results in deficient blood clotting. 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. A family history of bleeding disorder is a
risk factor.
Symptoms and Diagnosis
Signs and symptoms vary with the level of prothrombin. Patients with levels
greater than 50% of normal have no bleeding problems, whereas people with
levels from 2% to 50% may easily bruise or suffer from epistaxis, menorrhagia,
muscle hemorrhages, postpartum hemorrhages and hemorrhage following surgery
and trauma.
Symptoms include:
umbilical cord bleeding at birth
nose bleeds
abnormal menstrual bleeding
abnormal bleeding after delivery
bleeding after trauma
bleeding after surgery
easy bruising
Signs and Tests:
prolonged prothrombin time
prolonged partial thromboplastin time
factor II assay showing decreased activity
levels of prothrombin ranging from 2% to 50% of normal
Treatments
Treatment depends on the severity of the disorder and the type of bleeding.
Mild cases may be treated with plasma infusion. Loss of blood can be controlled
by infusions of fresh frozen plasma. Severe factor II deficiencies may be
treated with prothrombin complex concentrates (PCCs). When necessary, it
can be treated with plasma replacement therapy. Effective control of a hemorrhage
is achieved when prothrombin levels are at 30% to 50% of normal.
Genetic counseling may be helpful in the case of congenital disorders. The
use of vitamin K in malabsorption and long-term antibiotic use may be preventative.
If the disorder is caused by vitamin K deficiency, then vitamin K is prescribed.
Diagnosis of a bleeding disorder is important so that precautionary measures
can be taken if surgery is needed or anticipated.
The National Hemophilia Foundation's Medical and Scientific Advisory Council
(MASAC) made recommendations for treatment of factor II deficiency in November
of 1999. They include:
Prothrombin complex concentrates (PCCs) can be used, but these products
vary considerably in the amount of factors they contain.
Fresh frozen plasma can be used as along as it is processed to reduce
the risk of viral infection.
Complications
Bleeding has to be controlled in instances of trauma or surgery, or else
bleeding into the brain or skull can occur.
Disclaimer
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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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