Hemophilia

DEFINITION

Hemophilia is a rare disorder in which your blood doesn’t clot normally because it lacks sufficient blood-clotting proteins (clotting factors). If you have hemophilia, you may bleed for a longer time after an injury than you would if your blood clotted normally.

Small cuts usually aren’t much of a problem. The greater health concern is deep bleeding inside your body, especially in your knees, ankles and elbows. That internal bleeding can damage your organs and tissues, and may be life-threatening.

Hemophilia is an inherited (genetic) disorder. There’s no cure yet. But with proper treatment and self-care, most people with hemophilia can maintain an active, productive lifestyle.

CAUSES

When you bleed, your body normally pools blood cells together to form a clot to stop the bleeding. The clotting process is encouraged by certain blood particles (platelets and plasma proteins). Hemophilia occurs when you have a deficiency in one of these clotting factors.

Hemophilia is inherited. However, about 30 percent of people with hemophilia have no family history of the disorder. In these people hemophilia is caused by a genetic change (spontaneous mutation).

There are several types of hemophilia. They are classified according to which clotting factor is deficient:

• Hemophilia A, the most common type, is caused by insufficient clotting factor VIII.
• Hemophilia B, the second most common type, is caused by insufficient clotting factor IX.
• Hemophilia C, in which signs and symptoms are often mild, is caused by insufficient clotting factor XI.

Hemophilia inheritance

Everyone has two sex chromosomes, one from each parent. A female inherits an X chromosome from her mother and an X chromosome from her father. A male inherits an X chromosome from his mother and a Y chromosome from his father.

Hemophilia inheritance depends on your type of hemophilia:

• Hemophilia A or B. The gene that causes them is located on the X chromosome, so it can’t be passed from father to son. Hemophilia A or B almost always occurs in boys and is passed from mother to son through one of the mother’s genes. Most women with the defective gene are simply carriers and experience no signs or symptoms of hemophilia. Women can experience bleeding symptoms if their factor VIII or IX is moderately decreased.
• Hemophilia C. This disorder can be passed on to children by either parent. Hemophilia C can occur in girls and boys.

SYMPTOMS

Signs and symptoms of hemophilia vary, depending on your level of clotting factors. If your clotting-factor level is mildly reduced, you may bleed only after surgery or trauma. If your deficiency is severe, you may experience spontaneous bleeding.

Signs and symptoms of spontaneous bleeding include:

• Unexplained and excessive bleeding from cuts or injuries, or after surgery or dental work
• Many large or deep bruises
• Unusual bleeding after vaccinations
• Pain, swelling or tightness in your joints
• Blood in your urine or stool
• Nosebleeds without a known cause
• In infants, unexplained irritability

Emergency signs and symptoms of hemophilia include:

• Sudden pain, swelling and warmth in large joints, such as knees, elbows, hips and shoulders, and in your arm and leg muscles
• Bleeding from an injury, especially if you have a severe form of hemophilia
• Painful, prolonged headache
• Repeated vomiting
• Extreme fatigue
• Neck pain
• Double vision

When to see a doctor

Prolonged bleeding after circumcision may be the first indication of hemophilia in a baby boy. In boys who aren’t circumcised, easy bruising when the child becomes more mobile may lead to the diagnosis. The first episode of bleeding generally occurs by the time a child is 2 years old.

If your child bruises easily, see your doctor. If your child has heavy bleeding that can’t be stopped after an injury, seek emergency medical care.

If you’re pregnant or considering pregnancy, and have a family history of hemophilia, talk to your doctor. You may be referred to a specialist in medical genetics or bleeding disorders, who can help you determine if you are a carrier of hemophilia. If you are a carrier, it’s possible to determine during pregnancy if the fetus is affected by hemophilia.