Congenital afibrinogenemia is a rare, inherited blood disorder in which the blood does not clot normally. It occurs when there is a lack (deficiency) of a protein called fibrinogen, which is needed for the blood to clot.

This rare disease is caused by an abnormal gene that must be passed down from both parents. It causes a severe lack of fibrinogen. (Dysfibrinogenemia, in which there is a defect in fibrinogen function, is a different condition.)

Congenital afibrinogenemia can occur in males or females. The main risk factor is a family history of bleeding disorders.

• Bruising
• Bleeding in joints
• Excessive bleeding after injury or surgery
• Gastrointestinal bleeding
• Miscarriage
• Nosebleeds

If the health care provider suspects a bleeding disorder, laboratory tests can determine the type and extent. This disorder usually shows up in childhood, often at birth.

Tests include:

• Bleeding time
• Clotting time
• Fibrinogen levels
• Partial thromboplastin time (PTT)
• Prothrombin time (PT)
• Reptilase time
• Thrombin time

All of these tests are abnormal in afibrinogenemia.

To treat bleeding episodes or to prepare for surgery to treat other conditions, patients may receive:

• The liquid portion of the blood (plasma)
• A blood product containing concentrated fibrinogen (cryoprecipitate) through a vein (transfusion)

People with this condition should have the hepatitis B vaccine because transfusion increases the risk of hepatitis.

Excess bleeding is common with this condition. These episodes may be severe, or even fatal. Bleeding in the brain is a leading cause of death in patients with this disorder.

• Bleeding from the umbilical cord
• Bleeding from the mucus membranes
• Bleeding in the brain (intracranial bleeding)
• Clotting with treatment
• Development of antibodies (inhibitors) to fibrinogen with treatment
• Gastrointestinal bleeding

Call your health care provider or seek emergency care if you have excessive bleeding.

Tell your surgeon before you have surgery if you know or suspect you have a bleeding disorder.

There is no known prevention. Couples who are thinking about having children may find genetic counseling helpful if at least one partner has this condition.

Kessler C. Hemorrhagic disorders: Coagulation factor deficiencies. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 180.