Q: What is haemophilia?
A: Haemophilia is a blood disorder that primarily affects males. People who have haemophilia tend to bleed for longer periods of time following an injury or surgery. This happens because they have little, or even none, of a protein called clotting factor. Clotting factors help your blood form clots, which play an important role in stopping bleeding.
There are many of these clotting factors in the body that are needed for the blood to clot properly. People with haemophilia A lack (or have very little of) a clotting called factor VIII, while people with haemophilia B (also known as Christmas disease) are lacking a clotting factor called factor IX.
Q: How common is haemophilia?
A: Of the two main types of haemophilia, haemophilia A is the most common. About 1 in 1 in 5,000 males worldwide are born with haemophilia A. About 1 in 30,000 males worldwide are born with haemophilia B.
Q: Could I have haemophilia? Or could my children?
A: Haemophilia A and B are usually inherited. These conditions are caused by a genetic mutation of the gene that is used when the body produces clotting factor VIII or IX. The genes for these clotting factors are carried on the X chromosome. Women have two X chromosomes, whereas men have an X and a Y chromosome. A who inherits the genetic X chromosome from her father will not get haemophilia as the X chromosome she receives from her mother is dominant, and this X chromosome is a normal blood clotting gene. She is considered a carrier of haemophilia as she can pass on the X chromosome mutation she received from her father to her children.. Rarely do women who are carriers have any symptoms of haemophilia. And very rarely do women actually have haemophilia, which only happens when they have the haemophilia genetic mutation on both of their X chromosomes.
The son of a woman who is a carrier of the haemophilia gene mutation will have a 50% chance of having haemophilia. The daughter of a woman who is a carrier of the haemophilia gene mutation will have a 50% chance of carrying the gene mutation. Still, about one-third of children who are diagnosed with haemophilia have no family history of the disease. Their disease is the result of a spontaneous mutation.
Q: How is haemophilia diagnosed?
A: Newborn males with a family history of haemophilia are usually screened for the disease before they leave the hospital. When there is no known family history, many children are diagnosed when they begin to experience symptoms of the disease. For example, if an infant bleeds for a prolonged period of time after a circumcision, tests may be done to find out if haemophilia is the cause. Sometimes children who bruise often and very easily, are tested for haemophilia to see if that is the cause.
Q: What are the long-term health complications associated with haemophilia?
A: A common symptom of haemophilia is bleeding inside the joints. This can be very painful and affect joints in the knees, ankles, hips, and elbows. Even after the bleed stops, it causes scarring in the joints, which can lead to joint damage.
Q: What is the prognosis for someone diagnosed with haemophilia?
A: People with haemophilia can lead fairly normal lives, as long as certain precautions are taken. For example, they should avoid certain activities with an increased risk of injury, such as football and boxing. Instead, sports like swimming, golf, and tennis are preferred. There are also medications that can temporarily help replace the missing clotting factor in the person’s blood. People with haemophilia should talk to their doctor before participating in sports or any other physical activity. They can also discuss all of the available treatment options for preventing and treating bleeds and managing their health.
Dr. Bartholomew J. Tortella is a Medical Director on the Haemophilia team at Pfizer.
- 1. Epidemiology of Haemophilia. BMJ Best Practice. Accessed 14/2/2017.
- 2. Hemophilia US Centers for Disease Control.
- 3. Khayat CD. Once-weekly prophylactic dosing of recombinantfactor IX improves adherence in hemophilia B. J Blood Med 2016; 7: 275–282. doi: 10.2147/JBM.S84597 Accessed 14/2/2017.