What is hemophilia type C?
Hemophilia C is a rare genetic disorder caused by missing or defective blot clotting protein called Factor XI.
The disease was first recognized in 1953 in patients who experienced severe bleeding after dental extractions and to this day, it is still not very well-known.
Factor XI deficiency is inherited, meaning it’s transmitted from parent to child. The disorder may be caused by a myriad of genetic mutations, which is why symptoms vary greatly in people, with deficiencies similar to that of Factor XI (like von Willebrand disease).
Unlike classic hemophilia (A and B), hemophilia C affects men and women equally, as the faulty gene is located on chromosome 4.
Hemophilia C generally occurs in one of every 100,000 people. Among Ashkenazi Jews in Israel, however, the incidence of Factor XI deficiency is as high as 8 percent. This is because Factor XI deficiency is inherited in an autosomal recessive pattern, meaning both parents must carry the gene to pass it on to their children. There is a higher chance that two people related by blood both have a faulty copy of the Factor XI gene and therefore their children are more likely to inherit the disease.
Symptoms of hemophilia type C
Symptoms in hemophilia C do not correlate with Factor XI levels in the blood. In fact, people with lower levels may bleed less than those with higher levels of Factor XI. As a result, it is very difficult to predict the severity and frequency of bleeding simply on the basis of how much Factor XI is in the blood.
Prolonged bleeding may occur after major physical trauma such as an accident or surgery involving the mucosa of the mouth, nose or urinary tract. Tooth extraction, tonsillectomy and ablation of the uterus or prostate are examples of surgeries that entail a high risk of bleeding.
People with the disorder also have a strong tendency to develop nosebleeds and bruises, and more rarely, bleeding into the urine or intestines. However, they do not tend to bleed into muscles or joints. Therefore, they do not suffer the long-term effects associated with bleeding of this kind. Nor is there a high risk of suffering spontaneous intracranial bleeding, or bleeding inside the skull.
Testing for hemophilia type C
Factor XI plays an important role in the clotting cascade, which leads to clotting. It helps generate more thrombin, a protein that converts fibrinogen to fibrin, which traps platelets and helps hold a clot in place.
Hemophilia C is suspected when an individual presents symptoms of unusual bleeding or when a pre-surgery coagulation test known as a coagulogram indicates a clotting anomaly. Other tests used to diagnose hemophilia C include a bleeding time test, platelet function tests, and prothrombin time (PT) tests.
Problems specific to women
Women experience the effects of hemophilia C differently than men. Many women may not know they’re deficient in Factor XI until they experience menorrhagia (heavy menstrual periods) or postpartum bleeding (bleeding after giving birth).
The level of Factor XI varies very little during pregnancy. In fact, female hormones improve coagulation in women; that reduces the risk of bleeding during pregnancy or while taking oral contraceptives.
Nevertheless, the pregnancy and actual delivery does pose some bleeding risk. Therefore, hemophiliac women who become pregnant should consult a hematologist, not only for their own sake but also to check on their newborn.
Outside pregnancy, women with hemophilia C tend to have abundant menstruations that can lead to other problems such as anemia or fatigue.
Treatments for hemophilia type C
Various treatments are available for bleeding. These include:
- Fresh frozen plasma – a blood derivative that is rich in coagulation factor;
- Factor XI concentrate – delivered in lyophilized (powder) form and treated to inactivate blood-borne viruses;
- Hormone therapy – administered as birth-control pills, injections and intrauterine devices (IUDs);
- DDAVP (or the synthetic hormone desmopressin) – this encourages coagulation by temporarily increasing Factor VIII and von Willebrand coagulation factor;
- Cykokapron (tranexamic acid), which acts by helping hold the clot in place after it has formed.
- Practice daily dental care and regularly visit the dentist;
- Follow the same recommendations for every surgery;
- Never take aspirin, as it increases the tendency to bleed;
- Wear a MedicAlert identification bracelet containing information on your bleeding disorder, so emergency teams know how to treat you if you’re unconscious;
- Always be aware of the symptoms of your disorder;
- Notify your treatment center when planning a trip and ask for specialized treatment centers at your destination;
- Stay in contact with your hemophilia treatment center.
Hemophilia News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.