Factor VII deficiency
Proconvertin deficiency; Extrinsic factor deficiency; Serum prothrombin conversion accelerator deficiency; Alexander diseaseFactor VII (seven) deficiency is a disorder caused by a lack of a protein called factor VII in the blood. It leads to problems with blood clotting (coagulation).
Causes
When you bleed, a series of reactions take place in the body that helps blood clots form. This process is called the coagulation cascade. It involves special proteins called coagulation, or clotting factors. You may have a higher chance of excess bleeding if one or more of these factors are missing or are not functioning as they should.
Factor VII is one such coagulation factor. Factor VII deficiency runs in families (inherited) and is very rare. Both parents must have the gene to pass the disorder on to their children. A family history of a bleeding disorder can be a risk factor.
Factor VII deficiency can also be due to another condition or use of certain medicines. This is called acquired factor VII deficiency. It can be caused by:
- Low vitamin K (some babies are born with vitamin K deficiency)
- Severe liver disease
- Use of medicines that prevent clotting (anticoagulants such as warfarin)
Symptoms
Symptoms may include any of the following:
- Bleeding from mucus membranes
- Bleeding into joints
- Bleeding into muscles
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Bruising easily
Bruising
Bleeding into the skin can occur from broken blood vessels that form tiny red dots (called petechiae). Blood also can collect under the tissue in la...
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- Nosebleeds that do not stop easily
- Umbilical cord bleeding after birth
Exams and Tests
Tests that may be done include:
- Partial thromboplastin time (PTT)
PTT
Partial thromboplastin time (PTT) is a blood test that looks at how long it takes for blood to clot. It can help tell if you have a bleeding problem...
Read Article Now Book Mark Article - Plasma factor VII activity
Factor VII activity
The factor VII assay is a blood test to measure the activity of factor VII. This is one of the proteins in the body that helps the blood clot....
Read Article Now Book Mark Article - Prothrombin time (PT)
PT
Prothrombin time (PT) is a blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot. It measures the functio...
Read Article Now Book Mark Article - Mixing study, a special PTT test to confirm factor VII deficiency
Treatment
Bleeding can be controlled by getting intravenous (IV) infusions of normal plasma, concentrates of factor VII, or genetically produced (recombinant) factor VII.
You will need frequent treatment during bleeding episodes because factor VII does not last for long inside the body. A form of factor VII called NovoSeven can also be used.
If you have factor VII deficiency due to a lack of vitamin K, you can take this vitamin by mouth, through injections under the skin, or through a vein (intravenously).
If you have this bleeding disorder, be sure to:
- Tell your health care providers before you have any kind of procedure, including surgery and dental work.
- Tell your family members because they may have the same disorder but do not know it yet.
Support Groups
More information and support for people with Factor VII deficiency and their families can be found at:
- National Hemophilia Foundation -- www.hemophilia.org/community-resources
- National Organization for Rare Disorders -- rarediseases.org/rare-diseases/factor-vii-deficiency
Outlook (Prognosis)
You can expect a good outcome with proper treatment.
Inherited factor VII deficiency is a lifelong condition.
The outlook for acquired factor VII deficiency depends on the cause. If it is caused by liver disease, the outcome depends on how well your liver disease can be treated. Taking vitamin K supplements will treat vitamin K deficiency.
Possible Complications
Complications may include:
- Excessive bleeding (hemorrhage)
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Stroke or other nervous system problems from central nervous system bleeding
Stroke
A stroke occurs when blood flow to a part of the brain stops. A stroke is sometimes called a "brain attack. " If blood flow is cut off for longer th...
ImageRead Article Now Book Mark Article - Joint problems in severe cases when bleeding happens often
When to Contact a Medical Professional
Get emergency treatment right away if you have severe, unexplained bleeding.
Prevention
There is no known prevention for inherited factor VII deficiency. When a lack of vitamin K is the cause, using vitamin K can help.
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.
Hall JE, Hall ME. Hemostasis and blood coagulation. In Hall JE, Hall ME, eds. Guyton and Hall Textbook of Medical Physiology. 14th ed. Philadelphia, PA: Elsevier; 2021:chap 37.
Ragni MV. Hemorrhagic disorders: coagulation factor deficiencies. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine. 26th ed. Philadelphia, PA: Elsevier; 2020:chap 165.
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Blood clot formation - illustration
Blood clotting normally occurs when there is damage to a blood vessel. Platelets immediately begin to adhere to the cut edges of the vessel and release chemicals to attract even more platelets. A platelet plug is formed, and the external bleeding stops. Next, small molecules, called clotting factors, cause strands of blood-borne materials, called fibrin, to stick together and seal the inside of the wound. Eventually, the cut blood vessel heals and the blood clot dissolves after a few days.
Blood clot formation
illustration
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Blood clots - illustration
Blood clots (fibrin clots) are the clumps that result when blood coagulates.
Blood clots
illustration
-
Blood clot formation - illustration
Blood clotting normally occurs when there is damage to a blood vessel. Platelets immediately begin to adhere to the cut edges of the vessel and release chemicals to attract even more platelets. A platelet plug is formed, and the external bleeding stops. Next, small molecules, called clotting factors, cause strands of blood-borne materials, called fibrin, to stick together and seal the inside of the wound. Eventually, the cut blood vessel heals and the blood clot dissolves after a few days.
Blood clot formation
illustration
-
Blood clots - illustration
Blood clots (fibrin clots) are the clumps that result when blood coagulates.
Blood clots
illustration
Review Date: 2/2/2023
Reviewed By: Mark Levin, MD, Hematologist and Oncologist, Monsey, NY. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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