Alpha thalassemia (thal-uh-SEE-me-uh) is an inherited blood disorder in which the body has a problem producing alpha globin. Alpha globin is a component of hemoglobin, the protein in red blood cells (RBCs) that transports oxygen throughout the body.

More to Know

Hemoglobin contains two chains of alpha globin and two chains of beta globin. Alpha thalassemia happens when one of the genes controlling alpha globin production is absent or defective, causing faster than normal destruction of RBCs. This leads to anemia, which can cause fatigue and other complications, including bone deformities, slower growth rates, and organ damage.

Alpha globin is made by four genes, and one or more can be mutated or missing, so there are four kinds of alpha thalassemia:

1. People with one missing or abnormal gene are silent alpha thalassemia carriers; they have no symptoms, but can pass thalassemia on to their children.
2. People with one or two missing or mutated genes (alpha thalassemia trait) usually have no symptoms, but also can pass the disease on to their children.
3. People with three missing or mutated genes (hemoglobin H disease) will have moderate to severe symptoms.
4. Four missing or mutated genes (alpha thalassemia major or hydrops fetalis) almost always leads to a fetus dying before delivery or a newborn baby dying shortly after birth.

Treatment for alpha thalassemia depends on the severity of the symptoms and may include blood transfusions and folic acid supplements. A bone marrow transplant is the only known cure for alpha thalassemia, but since transplants carry many risks, they are usually done only in the most severe cases of thalassemia.

Keep in Mind

For many people with alpha thalassemia trait, whose only symptom is mild anemia from time to time, no medical treatment is necessary. Those who have a more severe type of the disease can reduce the risk of complications by eating a balanced diet, getting regular physical activity, taking steps to prevent colds or flu, and going to all their medical appointments as recommended.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.