Thalassemia
Topic Overview
What is thalassemia?
Thalassemia (say "thal-uh-SEE-mee-uh") is an inherited blood disorder that
causes the body to produce less hemoglobin. Hemoglobin
helps red
blood cells spread oxygen all through your body. Low levels of hemoglobin
may cause anemia, an illness that makes you feel weak and tired. Severe
cases of anemia may damage organs and result in death.
What causes thalassemia?
A defect in one or more genes causes thalassemia. It is an inherited blood disorder, passed from
parent to child. Both parents must carry a gene for the disease in order to pass it to their child.
What are the types of thalassemia?
Alpha thalassemia and beta thalassemia are the two main types of the disease. Beta is the most
common form. A "carrier" has one normal gene and one thalassemia gene in all body cells, a
state sometimes called "thalassemia trait." Most carriers lead completely normal, healthy lives.
Beta thalassemia
Beta thalassemia occurs when one or both of the genes that produce beta-globin don't work or
only partly work the way they should. People need both alpha- and beta-globin to make
hemoglobin. Beta thalassemia mainly affects people from the region around the Mediterranean
Sea (such as Greeks and Italians) and, less often, people of African or Asian descent.
There are several subtypes of beta thalassemia. Which type you have depends upon whether
one or both genes are affected and whether those genes still produce some working beta-globin.

If you carry the genetic trait for thalassemia or have one damaged beta-globin gene, you
may have mild anemia and probably will not need treatment. This condition is called beta
thalassemia minor or beta thalassemia trait. You have thalassemia trait when you inherit a
normal gene from one parent and a thalassemia gene from the other.

When both beta-globin genes are damaged, moderate or severe anemia may develop. In
this situation, you have inherited a thalassemia gene from each parent.
o
If you have moderate anemia (beta thalassemia intermedia), you may need
blood transfusions. People who have beta thalassemia intermedia usually live into adulthood.
o
People with severe anemia (called beta thalassemia major or Cooley's
anemia) usually will not live into adulthood without treatment. Symptoms of anemia usually
develop within 6 months of birth.1 If the child starts receiving blood transfusions early and
continues to receive them throughout life, he or she is likely to live longer. Death is usually a
result of damage to organs, such as the heart or liver. Lack of oxygen or an iron overload from
blood transfusions causes the organ damage.
Alpha thalassemia
Alpha thalassemia occurs when one or more of the four genes that are vital to making
hemoglobin are missing or damaged. Alpha thalassemia mainly affects people from southeast
Asia, China, and the Philippines, although it occurs in many populations throughout the world. It is
sometimes seen in people of African descent
There are four subtypes of alpha thalassemia. Each type represents the loss of or damage to
one, two, three, or four genes.
One gene: If one alpha-globin gene is missing or damaged, you will have no symptoms
and will not need treatment. But you are a silent carrier. This means you don't have
the disease but you can pass the defective gene onto your child. Smaller-than-normal
blood cells may be the only sign of the condition.
Two genes: If two alpha-globin genes are missing or damaged, you will have very mild
anemia that will not need treatment. This is known as alpha thalassemia minor or
alpha thalassemia trait.
Three genes: If three alpha-globin genes are missing, you will have mild to moderately
severe anemia. This is sometimes called hemoglobin H disease, because it
produces a heavy hemoglobin. The body removes this heavy hemoglobin faster than it
does normal hemoglobin. The more severe forms may need treatment with blood
transfusions.
Four genes: If all four alpha-globin genes are missing (alpha thalassemia major), the
fetus will be stillborn or the child will die shortly after birth.1 The hemoglobin produced
by this condition is sometimes called hemoglobin Barts.
What are the symptoms?
Mild thalassemia usually does not cause any symptoms. But symptoms of anemia may develop in
more severe forms of the condition and may include:
Weakness.
Fatigue.
Lightheadedness.
Skin that looks paler than normal.
Jaundice (skin and whites of the eyes appear yellow).
Dark urine.
Decreased appetite and weight loss (poor growth in a child).
A rapid heartbeat.
Shortness of breath during exercise.
How is thalassemia diagnosed?
A physical exam and complete medical history are usually the first steps in diagnosing
thalassemia. Tests that help confirm a diagnosis of thalassemia include:
Complete blood count (CBC) and blood smear.
Gene test.
Iron level test, to determine whether iron deficiency anemia is present.
A blood test that measures the amounts of different types of hemoglobin (hemoglobin
electrophoresis), to help find out which type of thalassemia you have.
A complete blood count (CBC) test on other members of your family (parents and
siblings), to discover whether they may also have thalassemia.
How is it treated?
Treatment for thalassemia depends on your symptoms.
Mild thalassemia, the most common form, does not need treatment.
Moderate thalassemia may be treated with folic acid supplements and blood transfusions.
Severe thalassemia may be treated with:
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Blood transfusions.
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Folic acid.
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A splenectomy, which is surgical removal of the spleen.
o
A bone marrow transplant, in some severe cases.
Very rare forms of thalassemia may cause organ damage that can result in death. This damage
occurs when not enough oxygen reaches the organs. Iron overload also may damage organs,
especially the liver. The body can get too much iron through repeated blood transfusions. If this
happens, your doctor may give you chelating therapy. Or you may get medicine that binds to the
iron in your body and removes it through your urine or stool. You may take this medicine as pill or
have it pumped under your skin through a thin tube.