Afibrinogenemia; Hypofibrinogenemia; Dysfibrinogenemia; Factor I deficiency
Congenital 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.
This disease is due to abnormal genes. Fibrinogen is affected depending on how the genes 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.
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. Those with a problem with the function of fibrinogen often don't have symptoms.
Exams and Tests
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.
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.
When to Contact a Medical Professional
Call 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.
This is an inherited condition. There is no known prevention.
Gailani D, Wheeler AP, Neff AT. Rare coagulation factor deficiencies. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice. 7th ed. Philadelphia, PA: Elsevier; 2018:chap 137.
Ragni MV. Hemorrhagic disorders: coagulation factor deficiencies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 165.
Last reviewed on: 1/19/2021
Reviewed by: Todd Gersten, MD, Hematology/Oncology, Florida Cancer Specialists & Research Institute, Wellington, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.