A group of hereditary bleeding disorders in which a blood-clotting factor is missing are known as

Overview

What is hemophilia?

Hemophilia is a rare, inherited bleeding disorder in which blood cannot clot normally at the site of a wound or injury. The disorder occurs because certain blood clotting factors are missing or do not work properly. Because a clot does not form, extensive bleeding can be caused from a cut or wound. This is called external bleeding. Bleeding inside the body, called internal bleeding, can occur as well, especially in muscles and in joints like the hips and knees.

Hemophilia affects males almost exclusively, but there are rare circumstances when a female can be affected with the disorder.

There are two main types of inherited hemophilia:

• Type A, the most common type, is caused by a deficiency of factor VIII, one of the proteins that helps blood to form clots. This type is known as classic hemophilia.
• Type B hemophilia is caused by a deficiency of factor IX. This type is also called Christmas disease.

Although hemophilia is usually diagnosed at birth, the disorder can also be acquired later in life if the body begins to produce antibodies that attack and destroy clotting factors. However, this acquired type of hemophilia is very rare. Acquired hemophilia is also called autoimmune hemophilia, or acquired hemophilia A (AHA).

How common is hemophilia?

Hemophilia is a rare disorder. It can occur in all races and ethnic groups. Hemophilia A affects 1 in 5,000 to 10,000 males. Hemophilia B is less common, affecting 1 in 25,000 to 30,000 males.

Around 60% to 70% of people with hemophilia A have the severe form of the disorder and about 15% have the moderate form. The rest have mild hemophilia.

Is hemophilia contagious?

No. Hemophilia is caused by mutations in the genes encoding factor VIII and IX. You can’t catch it from someone who has it like you can catch a cold.

Symptoms and Causes

What causes hemophilia?

The genes that regulate the production of factors VIII and IX are found on the X chromosome only. Hemophilia is caused by mutations in either the factor VIII or factor IX genes on the X chromosome.

If a woman carries the abnormal gene on one of her X chromosomes (females have a pair of X chromosomes), she will not have hemophilia herself, but she will be a carrier of the disorder. That means that she can pass the gene for hemophilia on to her children. There is a 50% chance that any of her sons will inherit the gene and will be born with hemophilia. There is also a 50% chance that any of her daughters will be carriers of the gene without having hemophilia themselves.

It is very rare for a girl to be born with hemophilia, but it can happen if the father has hemophilia and the mother carries the gene for hemophilia. The daughter will then have the abnormal gene on both of her X chromosomes.

In about 20% of all cases of hemophilia, the disorder is caused by a spontaneous gene mutation. In such cases there is no family history of abnormal bleeding.

What are the symptoms of hemophilia?

The major symptom is bleeding, either prolonged external bleeding or bruising after minor trauma or for no apparent reason. Symptoms vary depending on whether the patient has the mild, moderate, or severe form of the disorder:

• In severe hemophilia, unprovoked (spontaneous) bleeding episodes occur often.
• In moderate hemophilia, prolonged bleeding tends to occur after a more significant injury.
• In mild hemophilia, a patient might have unusual bleeding, but only after a major injury, surgery, or trauma.

People with hemophilia may have any type of internal bleeding, but most often it occurs in the muscles and joints, such as the elbows, knees, hips, shoulders and ankles. There may be no pain at first, but if the bleeding continues, the joint may become hot to the touch, swollen, and painful to move.

Repeated bleeding into the joints and muscles over time may cause permanent damage, such as joint deformity and reduced mobility.

Bleeding in the brain is a very serious problem for those with severe hemophilia. It may be life-threatening. Get medical help immediately if you have signs of bleeding, such as:

• Changes in behavior.
• Excessive sleepiness.
• Headache that will not go away.
• Neck pain.
• Double vision.
• Vomiting.
• Convulsions or seizures.

Diagnosis and Tests

How is hemophilia diagnosed?

Your doctor will perform a physical examination to rule out other conditions. If you have symptoms of hemophilia, the provider will ask about your family’s medical history since this disorder tends to run in families. In children with severe hemophilia, the diagnosis is usually made in infancy. This might happen at the time of circumcision or when the toddler starts to walk and develops excessive bleeding or bruising with minor trauma.

Blood tests are then performed to determine how much factor VIII or factor IX is present. These tests will show which type of hemophilia you have and whether it is mild, moderate, or severe, depending on the level of clotting factor in the blood:

• People who have 5%-30% of the normal amount of clotting factors in their blood have mild hemophilia.
• People with 1%-5% of the normal level of clotting factors have moderate hemophilia.
• People with less than 1% of the normal clotting factors have severe hemophilia.

Your doctor may request that other family members have a Factor VIII level drawn to determine if they are affected. In some cases genetic testing may be necessary.

Management and Treatment

How is hemophilia treated?

Treatment depends on the type and severity of the disorder. It consists of replacement therapy, in which human plasma concentrates or recombinant (produced from DNA) forms of the clotting factors VIII or IX are given to replace the blood clotting factors that are missing or deficient.

• Blood factor concentrates are made from donated human blood that has been treated and screened to reduce the risk of transmitting infectious diseases, such as hepatitis and HIV.
• Recombinant clotting factors, which are made in the laboratory and not from human blood, are commonly used today.
• Recombinant FVIII and FIX products, modified to survive longer in the circulation, are now available. They required less frequent dosing for prophylaxis or prevention of bleeding.
• Newer non-factor products are also being developed for prophylactic use in hemophilia. These have the advantage of much less frequent administration, and in some cases do not require intravenous administration.

During replacement therapy, the clotting factors are injected or infused (dripped) into a patient’s vein in the arm or a port in the chest. Usually, people with mild or moderate hemophilia do not need replacement therapy unless they are going to have surgery.

• In cases of severe hemophilia, treatment may be given to stop bleeding when it occurs. Patients who have frequent bleeding episodes may be candidates for prophylactic factor infusions. These are given two or three times per week to prevent bleeding from occurring.
• Some people with the mild or moderate form of hemophilia type A can be treated with desmopressin (DDAVP®), a synthetic (man-made) hormone that helps to stimulate the release of factor VIII and another blood factor that carries and binds to it. Sometimes desmopressin is given as a preventive measure before a person with hemophilia has dental work or some other minor surgical procedure. Desmopressin does not work for people with type B hemophilia or severe hemophilia A.
• Aminocaproic acid or tranexamic acid are agents that prevent clots from breaking down (“antifibrinolytics”). They may be used as an added therapy to treat nosebleeds or bleeding from having a tooth removed.

The only absolute cure for hemophilia is a liver transplant. However, much progress is being made in finding a genetic cure for persons with hemophilia.

People with hemophilia who are treated with either plasma-purified or recombinant factor products may develop antibodies, called inhibitors, which will attack and neutralize their clotting factor. This is a severe complication that makes it very difficult to treat or prevent bleeding episodes. About one-third to one-fifth of people who have severe hemophilia A might develop an inhibitor. Inhibitors are much less common in hemophilia B. Hemophilia patients are tested frequently for a factor inhibitor, especially in childhood when they are first starting replacement therapy.

If you have an inhibitor, there are alternative medications that can bypass its negative effect and successfully treat a bleeding episode. For long-term control, however, a technique called immune tolerance induction (or ITI) is used to bring down the level of the inhibitor and enable factor replacement to work again. The protocol consists of daily doses of clotting factors given over a period of time, weeks or even years in some cases. Some people may also get immune-suppressing drugs. ITI is successful in about 70% of people with hemophilia A, and 30% for hemophilia B. New agents, specifically for patients with inhibitors have been developed and are quite effective. Your healthcare provider will discuss these options with you.

Are there home treatments for bleeds in people with hemophilia?

In most cases a child with severe hemophilia is managed at home by his parents, with the administration of factor on a prophylactic schedule. As the child gets older, he is taught how to self-administer his factor on schedule or when an acute bleed occurs. At the time of a joint bleed, you can treat the pain using the “RICE” (Rest, Ice, Compression, Elevation) protocol.

Pain medications are limited in hemophilia because common pain relievers such as aspirin, ibuprofen and naproxen can aggravate bleeding. If you or your child is suffering from pain related to an injury, you can use acetaminophen (sold under the brand name Tylenol®).

Prevention

How can I prevent hemophilia?

You cannot prevent hemophilia. It is a genetic condition that is inherited from the maternal side of your family.

Outlook / Prognosis

What is the outlook for people with hemophilia?

People with hemophilia can expect to have a lifespan and lifestyle that is relatively normal, as long as they are educated about their condition and have adequate treatment. The outlook for people with inhibitors is less hopeful, especially for those who are considered high responders. (Their immune system is very active against the clotting factors.) However, with the new medications being developed for this patient group there is reason for optimism.

When should I contact the doctor if I have hemophilia or if my child has hemophilia?

After a head injury you should go to an emergency room immediately, especially if symptoms such as headache, weakness and vomiting develop. With head trauma, you or your child should not take any type of pain reliever until you are told to do so by your doctor.

You should also contact your doctor or go to the emergency room in the case of other injuries in which bleeding cannot be easily controlled with factor infusion and local measures.

Living With

What should you know about living with hemophilia?

Here are some general guidelines that might be helpful.

If your child has hemophilia, make sure school and babysitters understand special needs. Keep a first aid kit with you at all times. Minor cuts can usually be treated with gauze, pressure, and bandages. Raise the affected part of the body.

Remember—people with hemophilia should not take aspirin or ibuprofen. These medicines can interfere with blood clotting.

Make sure to get vaccines against hepatitis A and B to make sure clotting factors made from donated blood are even safer.

Finally, follow the recommendations that people who do not have hemophilia follow to maintain good health:

• Exercise regularly (swimming is particularly good).
• Eat healthy foods to maintain a healthy weight.
• Practice good dental hygiene.

Resources

Are there resources for people with hemophilia?

You may find this information to be helpful:

• National Hemophilia Foundation.
  Community Resources.
• Hope for Hemophilia.
  Resources.
• Hemophilia Federation of America.
  Learn more.

What is a group of hereditary bleeding disorders in which a blood clotting factor is missing?

Is a group of hereditary bleeding disorders?

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What is the condition called when someone lacks clotting factors?