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


Factor XII Deficiency
(Hageman Factor)

What Is It?
First described in 1955, after routine blood tests before surgery on a man named John Hageman, factor XII deficiency is a very rare bleeding disorder. As a group, Asians are born with the deficiency more than any other ethnic group.

The deficiency is somewhat of a medical mystery. It does not cause abnormal bleeding, even with major surgical procedures. The hallmark of severe factor XII deficiency is prolonged APTT—usually more than 100 seconds—in a patient with no history of bleeding.

The outcome is expected to be good even without treatment.

Inheritance Pattern
The disorder is not sex-linked as is hemophilia. It affects both males and females with equal frequency. It is an autosomal recessive disorder, 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.

Symptoms & Diagnosis
There are usually no symptoms for factor XII deficiency. Diagnostic signs and tests include:
• Prolonged partial thromboplastin time
• Abnormal factor XII assay

Treatments
Because hemorrhaging and excessive bleeding are not associated with the deficiency, treatment is generally unnecessary.

Complications
There are usually no complications. However, it's been suggested that factor XII deficiency may predispose to thrombosis.

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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