Congenital afibrinogenemia is a rare, inherited blood disorder in which the blood does not clot normally. It occurs when there is a complete 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.

Milder forms can occur in people who inherit only one abnormal gene from their parents. (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 from the umbilical cord just after birth
• Bleeding in joints
• Excessive bleeding after injury or surgery
• Nosebleeds

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

Tests include:

• Bleeding 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:

• Cryoprecipitate (a blood product containing concentrated fibrinogen and other clotting factors) through a vein (transfusion)
• Fibrinogen (RiaSTAP)
• Plasma (the liquid portion of the blood containing clotting factors)

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
• Miscarriage

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.

Gailani D, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ Jr., Shattil SJ, et al, eds. Hoffman Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone Elsevier; 2008:chap 127.

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