Congenital fibrinogen deficiency
Afibrinogenemia; Hypofibrinogenemia; Dysfibrinogenemia; Factor I deficiencyCongenital fibrinogen deficiency is a very rare, inherited blood disorder in which the blood does not clot normally. It affects a protein called fibrinogen. This protein is needed for the blood to clot.
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Causes
This disease is due to a deficiency of the amount or function of fibrinogen. How fibrinogen is affected depends on how the genes that determine how it is formed are inherited:
- When the abnormal gene is passed down from both parents, a person will have a complete lack of fibrinogen (afibrinogenemia).
- When the abnormal gene is passed down from one parent, a person will have either a reduced level of fibrinogen (hypofibrinogenemia) or a problem with the function of fibrinogen (dysfibrinogenemia). Sometimes, these two fibrinogen problems can occur in the same person.
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Symptoms
People with a complete lack of fibrinogen may have any of the following bleeding symptoms:
- Bruising easily
- Bleeding from the umbilical cord just after birth
- Bleeding in the mucous membranes
- Bleeding in the brain (very rare)
- Bleeding in the joints
- Heavy bleeding after injury or surgery
- Nosebleeds that do not stop easily
People with a reduced level of fibrinogen bleed less often and the bleeding is not as severe when compared to people with no fibrinogen at all. Those with a problem with the function of fibrinogen often don't have symptoms.
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Exams and Tests
If your health care provider suspects this problem, you will have lab tests to confirm the type and severity of the disorder.
Tests include:
- Bleeding time
- Fibrinogen test and reptilase time to check fibrin level and quality
- Partial thromboplastin time (PTT)
- Prothrombin time (PT)
- Thrombin time
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Treatment
The following treatments can be used for bleeding episodes or to prepare for surgery:
- Cryoprecipitate (a blood product containing concentrated fibrinogen and other clotting factors)
- Fibrinogen (RiaSTAP)
- Plasma (the liquid portion of the blood containing clotting factors)
People with this condition should get the hepatitis B vaccine. Having many transfusions raises your risk of getting hepatitis.
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Outlook (Prognosis)
Excessive 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 people with this disorder.
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Possible Complications
Complications may include:
- Blood clots with treatment
- Development of antibodies (inhibitors) to fibrinogen with treatment
- Gastrointestinal bleeding
- Miscarriage
- Rupture of the spleen
- Slow healing of wounds
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When to Contact a Medical Professional
Contact your 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.
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Prevention
This is an inherited condition. There is no known prevention.
References
Gailani D, Benjamin TF, Wheeler AP. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 135.
Ragni MV. Hemorrhagic disorders: coagulation factor deficiencies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 165.