Alternative Names congenital factor VIII deficiency
Definition Haemophilia A is an inherited condition. It results from a lack of an important blood clotting protein.
What is going on in the body? An individual with haemophilia A has poor blood clotting. The missing clotting protein, which is called factor VIII, causes the problem. Haemophilia A is one of the most common inherited bleeding disorders. It affects primarily men.
What are the signs and symptoms of the disease? Problems usually start in early childhood. Severe cases will cause:
In someone with mild haemophilia, excessive bleeding may occur only with injury or surgery.
What are the causes and risks of the disease? Inheriting an abnormal X chromosome usually causes haemophilia. This chromosome is usually passed down from the mother. Men have only one X chromosome, while women normally have two. This means that a woman usually has to inherit two abnormal X-chromosomes, while men only need one, to get the disease. Because of this, males more commonly get haemophilia.
What can be done to prevent the disease? Haemophilia A is a genetic disease. The disease cannot be prevented in a person who is born with this gene. Genetic screening can tell individuals if they are carriers of the disease. Since haemophilia A is a treatable disease, genetic counselling before or during pregnancy can be helpful to couples with a family history of the disease.
An unborn foetus can also be tested for haemophilia. The testing can be done as early as the first trimester, with chorionic villi sampling or amniocentesis. These tests carry a small risk of causing a miscarriage.
How is the disease diagnosed? Haemophilia A is diagnosed by measuring the level of factor VIII in the blood. Other blood tests may also be performed to make sure there is not another cause for low factor VIII levels.
What are the long-term effects of the disease? Long term effects of haemophilia A are usually only seen with moderate to severe disease. Possibilities include:
bleeding into the brain, resulting in strokes and mental disabilities
damage from bleeding. This includes joint deformity, arthritis, and muscle stiffness.
abnormal iron deposits in the liver and other organs, which may cause damage
What are the risks to others? This is not a contagious disease. Someone with haemophilia or a family history of haemophilia may find genetic counselling helpful. This will determine the risk of passing on the abnormal gene to the children or grandchildren.
What are the treatments for the disease? A person with haemophilia A may receive regular transfusions of factor VIII. Other transfusions may be needed in an emergency or before surgery. Medications may also be needed for treatment of the condition or complications. For example, a medication called DDAVP may increase factor VIII levels.
Factor VIII is given by slow, intravenous infusion. A person can do this at home. A person who requires frequent infusions often has a central line surgically implanted. This is a catheter that goes into one of the large veins, and provides a painless way to give the factor VIII. Serious haemorrhage may require treatment in the hospital.
Some persons have immune system problems that make haemophilia A worse. These persons may require treatment with medications to suppress the immune system.
Chronic joint deformity due to haemophilia is becoming less common. However, some individuals require operations for joint problems. The most common sites for surgery include the weight bearing bones of the hips and knees.
What are the side effects of the treatments? All medications have side effects, including allergic reactions and stomach upset. Surgery carries a risk of bleeding, infection or allergic reaction to the anaesthesia.
Before current screening procedures, a factor VIII transfusion carried a risk of HIV or hepatitis. Currently, with present screening techniques for factor VIII products, the risk of acquiring hepatitis and HIV is very low. Individuals who have only been receiving blood products in the past 10 years have a very low risk of acquiring hepatitis and HIV from factor VIII products.
What happens after treatment for the disease? Lifelong treatment and monitoring are generally required.
How is the disease monitored? An individual with severe disease may need to have factor VIII levels checked often. Others may require only periodic monitoring and blood tests.
Author: Thomas Fisher, MD Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request
