Thalassemia

Thalassemia Definition Thalassemia — also called Mediterranean anemia — is an inherited blood disorder characterized by less hemoglobin and fewer red blood cells in your body than normal. Defects in the genes that make hemoglobin cause thalassemia. Hemoglobin is the substance in red blood cells that allows the cells to carry oxygen from your lungs to the other parts of your body. Because of low hemoglobin and a low amount of red blood cells, thalassemia results in anemia. If you have a mild form of thalassemia, you may not require any treatment. But, if you have a more severe form, you may need blood transfusions on a regular basis. Although in some cases severe thalassemia can be life-threatening, milder forms of thalassemia usually can be effectively treated. Although thalassemia causes anemia, don't confuse thalassemia with iron deficiency anemia. People with thalassemia often have more iron in their bodies than they need. For this reason, if you have thalassemia, don't take iron supplements unless your doctor recommends it.

Symptoms Signs and symptoms of thalassemia include:        

Fatigue Weakness Shortness of breath Yellow discoloration of the skin (jaundice) Bone deformities in the face Slow growth Protruding abdomen Dark urine

The signs and symptoms you experience depend on your type and severity of thalassemia. Some babies show signs and symptoms of thalassemia at birth, while others may not develop signs or symptoms until they're about 6 to 12 months old. Some people who have only one hemoglobin gene affected don't experience any thalassemia symptoms.

Causes Blood consists of liquid, called plasma, and three types of cells that float within the plasma:  

White blood cells. These blood cells fight infection. Platelets. These blood cells help your blood clot after a cut.

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Red blood cells (erythrocytes). These blood cells carry oxygen from your lungs, through your bloodstream, to your brain and your body's other organs and tissues. Your body needs a supply of oxygenated blood to function. Oxygenated blood helps give your body its energy and your skin a healthy glow.

Red blood cells contain hemoglobin — a red, iron-rich protein that gives blood its red color. Hemoglobin enables red blood cells to carry oxygen from your lungs to all parts of your body and to carry carbon dioxide from other parts of your body to your lungs so that it can be exhaled. Most blood cells, including red blood cells, are produced regularly in your bone marrow — a red, spongy material found within the cavities of many of your large bones. Thalassemia disrupts the normal production of hemoglobin and leads to a low level of hemoglobin and a high rate of red blood cell destruction, causing anemia. When you're anemic, your blood doesn't have enough red blood cells to carry oxygen to your tissues — leaving you fatigued. Thalassemia is caused by defects in the genes that make hemoglobin. The only way to get thalassemia is to inherit one or more defective hemoglobin genes from your parents. There are two types of thalassemia: alpha and beta, named for the two protein chains that make up normal hemoglobin. The type of thalassemia you have depends on the type of defective gene you inherit. Alpha-thalassemia Four genes are involved in making the alpha hemoglobin chain. You get two from each of your parents. If one or more of the alpha hemoglobin genes are defective, you develop alpha-thalassemia. The more defective genes you have, the more severe your alpha-thalassemia: 

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One gene. If only one of your alpha hemoglobin genes is defective, you'll have no signs or symptoms of thalassemia. But, you're a carrier of the disease and can pass it on to your children. Two genes. If you have two defective alpha hemoglobin genes, thalassemia signs and symptoms are mild. This condition is called alpha-thalassemia minor. Three genes. If three of your alpha hemoglobin genes are defective, your signs and symptoms will be moderate to severe. This condition is also called hemoglobin H disease. Four genes. When all four alpha hemoglobin genes are defective, the condition is called alpha-thalassemia major or hydrops fetalis. It usually causes a fetus to die before delivery or shortly after birth.

Beta-thalassemia Two genes are involved in making the beta hemoglobin chain. You get one from each of your parents. If one or both of the beta hemoglobin genes are defective, you develop beta-thalassemia.

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One gene. If one of your beta hemoglobin genes is defective, you have mild signs and symptoms. This condition is called beta-thalassemia minor. Two genes. If both of your beta hemoglobin genes are defective, your signs and symptoms will be moderate to severe. This condition is called betathalassemia major or Cooley's anemia. Babies born with two defective beta hemoglobin genes usually are healthy at birth, but develop signs and symptoms within the first year of life.

Risk factors Factors that increase your risk of thalassemia include:  

Family history. Thalassemia is an inherited disorder, passed from parents to children through defective hemoglobin genes. Ancestry. Thalassemia occurs most often in people of Italian, Greek, Middle Eastern, southern Asian and African ancestry. Alpha-thalassemia affects mainly people of Southeast Asian, Chinese and Filipino descent.

When to seek medical advice Make an appointment with your child's health care provider for an evaluation if he or she has any of the following signs or symptoms of thalassemia:        

Fatigue Weakness Shortness of breath Yellow discoloration of the skin (jaundice) Bone deformities in the face Slow growth Protruding abdomen Dark urine

Tests and diagnosis Most children who have moderate to severe cases of thalassemia show signs and symptoms within their first two years of life. If your doctor suspects your child has thalassemia, he or she may confirm a diagnosis using blood tests. If your child has thalassemia, blood tests may reveal a low level of red blood cells. The red blood cells may be smaller than normal, pale (a sign of low hemoglobin), varied in size and shape, and have uneven hemoglobin distribution — giving the cells a bull's-eye appearance under the microscope. Blood tests may also be used to measure the amount of iron in your child's blood and to evaluate his or her hemoglobin. In some cases, a blood test may be used for DNA analysis to diagnose thalassemia or to determine if a person is carrying defective hemoglobin genes.

Prenatal testing Testing can be done before a baby is born to find out if he or she has thalassemia and determine how severe it may be. Tests used to diagnose thalassemia in unborn babies include:  

Chorionic villi sampling. This test is usually done around the 11th week of pregnancy and involves removing a tiny piece of the placenta for evaluation. Amniocentesis. This test is usually done around the 16th week of pregnancy and involves taking a sample of the fluid that surrounds the baby.

Assisted reproductive technology A form of assisted reproductive technology that combines pre-implantation genetic diagnosis with in vitro fertilization may help parents who have thalassemia or who are carriers of a defective hemoglobin gene give birth to healthy babies. The procedure involves retrieving mature eggs from a woman and fertilizing them with a man's sperm in a dish in a laboratory. The embryos are tested for the defective genes and only those without genetic defects are implanted in the woman.

Complications Possible complications of thalassemia include: 

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Iron overload. People with thalassemia can get too much iron in their bodies, either from the disease itself or from frequent blood transfusions. Too much iron can result in damage to your heart, liver and endocrine system, which includes glands that produce hormones that regulate processes throughout your body. Infection. Thalassemia increases your risk of developing a blood-borne infection, such as hepatitis, which is a virus that can damage your liver.

In cases of severe thalassemia, the following complications can occur: 

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Bone deformities. Thalassemia can make your bone marrow expand, which causes your bones to widen. This can result in abnormal bone structure, especially in your face and skull. Bone marrow expansion also makes bones thin and brittle, increasing the chance of broken bones, particularly in your spine. Spine factures can result in compression of your spinal cord. Enlarged spleen (splenomegaly). The spleen helps your body fight infection and filter unwanted material, such as old or damaged blood cells. Thalassemia often destroys a large number of red blood cells, making your spleen work harder than normal, which causes it to enlarge. Splenomegaly can make anemia worse, and it can reduce the life of transfused red blood cells. If your spleen becomes too large, it may need to be removed. Slowed growth rates. Anemia can cause a child's growth to slow. Children with severe thalassemia rarely reach a normal adult height. Due to endocrine problems, puberty may also be delayed in these children. Heart problems. Heart problems, such as congestive heart failure and abnormal heart rhythms (arrhythmias), may be associated with severe thalassemia.

Treatments and drugs Treatment for thalassemia depends on which type you have and how severe it is. Thalassemia minor (alpha or beta) Signs and symptoms are usually mild with thalassemia minor and little, if any, treatment is needed. Occasionally, you may need a blood transfusion, particularly after surgery, after having a baby or if you develop an infection. Beta-thalassemia major (Cooley's anemia) or hemoglobin H disease These more severe forms of thalassemia often require frequent blood transfusions. Over time, blood transfusions cause a buildup of iron in your blood, which can damage your heart, liver and other organs. To help your body get rid of the extra iron, you may need to take medications known as "iron chelators." These medications may be given as a pill or as an infusion under your skin. In some cases, a bone marrow transplant or a stem cell transplant may be used to treat severe thalassemia.

Prevention In most cases, thalassemia cannot be prevented. If you have thalassemia, or if you carry a thalassemia gene, consider talking with a genetic counselor for guidance before you have a child.

Lifestyle and home remedies If you have thalassemia, be sure to:  

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Avoid excess iron. Unless your doctor recommends it, don't take vitamins or other supplements that contain iron. Eat a healthy diet. Eating a well-balanced diet that contains plenty of nutritious foods can help you feel better and boost your energy. Your doctor may also recommend you take a folic acid supplement to help your body make new red blood cells. Avoid infections. Protect yourself from infections with frequent hand washing and by avoiding sick people. You should also get a flu shot every year and the pneumoccoccal vaccine to prevent infections. If you develop a fever or other signs and symptoms of an infection, see your doctor for treatment.

Coping and support Coping with thalassemia can be challenging. But, you don't have to do it alone. If you have questions or would like guidance, talk with a member of your health care team. You may also benefit from joining a support group. Such a group can provide both sympathetic listening and useful information. To find out about support groups in your area that deal with thalassemia, ask your doctor.