Thalassemia

Thalassemia is an inherited blood disorder characterized by less hemoglobin and fewer red blood cells in your body than normal. Several types of thalassemia exist, including  alpha-thalassemia, beta-thalassemia, Cooley's anemia and Mediterranean anemia.

Hemoglobin is the substance in your red blood cells that allows them to carry oxygen. The low hemoglobin and fewer red blood cells of thalassemia may cause anemia, leaving you fatigued.

If you have mild thalassemia, you may not need treatment. But, if you have a more severe form of thalassemia, you may need regular blood transfusions.

 Symptoms

§           Fatigue

§          Weakness

§         Shortness of breath

§         Pale appearance

§         Irritability

§        Yellow discoloration of skin (jaundice)

§       Facial bone deformities

§      Slow growth

§      Abdominal swelling

§      Dark urine

The signs and symptoms you experience depend on the type and severity of thalassemia you have. Some babies show signs and symptoms of thalassemia at birth, while others may develop signs or symptoms during the first two years of life. Some people who have only one affected hemoglobin gene don't experience any thalassemia symptoms. In most cases, thalassemia can't be prevented. If you have thalassemia, or if you carry a thalassemia gene, consider talking with a genetic counselor for guidance before you have or father a child.

You may contract thalassemia from one or both parents. When contracting the blood disorder from one parent the disease is called thalassemia minor and you will only carry the disease and not suffer any symptoms. Thalassemia major is inherited from both parents and you can suffer symptoms and carry the disease.

Causes

Thalassemia is caused by mutations in the DNA of cells that make hemoglobin — the substance in your red blood cells that carries oxygen throughout your body. The mutations associated with thalassemia are passed from parents to children.

The mutations that cause thalassemia disrupt the normal production of hemoglobin and cause low hemoglobin levels 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.

Types of Thalassemia 

The type of thalassemia you have depends on the number of gene mutations you inherit from your parents and which part of the hemoglobin molecule is affected by the mutations. The more mutated genes, the more severe your thalassemia. Hemoglobin molecules are made of alpha and beta parts that can be affected by mutations.

Alpha-thalassemia 
Four genes are involved in making the alpha hemoglobin chain. You get two from each of your parents. If you inherit:

§     One mutated gene- 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 mutated genes- your thalassemia signs and symptoms will be mild. This condition may be called alpha-thalassemia minor, or you may be told you have an alpha-thalassemia trait.

§     Three mutated genes- your signs and symptoms will be moderate to severe. This condition is also called hemoglobin H disease.

§      Four mutated genes-the condition is called alpha-thalassemia major or hydrops fetalis. It usually causes a fetus to die before delivery or a newborn to die shortly after birth.

Beta-thalassemia 

 Diagram showing one example of how beta thalassemia is inherited. The beta globin gene is located on chromosome 11. A child inherits two beta globin genes-one from each parent. In this example, each parent has one altered beta globin gene. 

Two genes are involved in making the beta hemoglobin chain. You get one from each of your parents. If you inherit:

§     One mutated gene- you'll have mild signs and symptoms. This condition is called beta-thalassemia minor or referred to as a beta-thalassemia trait.

§     Two mutated genes- your signs and symptoms will be moderate to severe. This condition is called beta-thalassemia 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 two years of life.

Risk

Factors that increase your risk of thalassemia include:

§      Family history of thalassemia. Thalassemia is passed from parents to children through mutated hemoglobin genes. If you have a family history of thalassemia, you may have an increased risk of the condition.

§     Certain ancestry. Thalassemia occurs most often in people of Italian, Greek, Middle Eastern, Asian and African ancestry.

§   

Complications

Possible complications of thalassemia include:

§     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. People with thalassemia have an increased risk of infection. This is especially true if you've had your spleen removed.

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

§     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.

§     Enlarged spleen (splenomegaly). The spleen helps your body fight infection and filter unwanted material, such as old or damaged blood cells. Thalassemia is often accompanied by the destruction of a large number of red blood cells, making your spleen work harder than normal, causing it to enlarge. Splenomegaly can make anemia worse, and it can reduce the life of transfused red blood cells. If your spleen grows too big, it may need to be removed.

§      Slowed growth rates. Anemia can cause a child's growth to slow. Puberty also may be delayed in children with thalassemia.

§      Heart problems. Heart problems, such as congestive heart failure and abnormal heart rhythms (arrhythmias), may be associated with severe thalassemia.

 

 

Tests and diagnosis

If your child has thalassemia, blood tests may reveal:

§     A low level of red blood cells

§      Smaller than expected red blood cells

§      Pale red blood cells

§        Red blood cells that are varied in size and shape

     Red blood cells with uneven hemoglobin distribution, which gives 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

§      Evaluate his or her hemoglobin

§     Perform DNA analysis to diagnose thalassemia or to determine if a person is carrying mutated hemoglobin genes

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

§     Chorionic villus 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 fetus.

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.

 

Treatments

Treatment for thalassemia depends on which type you have and how severe it is.

Treatments for mild thalassemia 
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 to help manage thalassemia complications.

Treatment for moderate to severe thalassemia 
Frequent blood transfusions.-More-severe forms of thalassemia often require frequent blood transfusions, possibly every few weeks. 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 that rid your body of extra iron.

§     Stem cell transplant.- Also called a bone marrow transplant, a stem cell transplant may be used to treat severe thalassemia in select cases. Prior to a stem cell transplant, you receive very high doses of drugs or radiation to destroy your diseased bone marrow. Then you receive infusions of stem cells from a compatible donor. However, because these procedures have serious risks, including death, they're generally reserved for people with the most severe disease who have a well-matched donor available — usually a sibling.

Lifestyle

 

If you have thalassemia, be sure to:

§      Avoid excess iron-Unless your doctor recommends it, don't take vitamins or other supplements that contain iron.

§      Eat a healthy diet- Eating a 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. Also, to keep your bones healthy, make sure your diet contains adequate calcium and vitamin D. Ask your doctor what the right amounts are for you, and whether you need to take a supplement.

§     Avoid infections- Protect yourself from infections with frequent hand-washing and by avoiding sick people. This is especially important if you've had to have your spleen removed. You'll also need an annual flu shot, as well as the meningitis, pneumococcal and hepatitis B vaccines to prevent infections. 

Take your iron chelation medicine. This is important because the leading cause of death among people with thalassemias is heart disease caused by iron overload. Iron buildup can damage your heart, liver, and other organs. Although the iron chelation treatment can take time and be mildly painful, it's important that you don't stop taking your medicine.

Several chelation treatments are now available, including injections and pills. Your doctor will talk to you about which treatment is best for you.