"thal-uh-SEE-mee-uh") is an inherited blood disorder that causes your body to
hemoglobin or abnormal hemoglobin.
Hemoglobin helps red blood cells spread oxygen through
your body. Low levels of hemoglobin may cause
anemia, an illness that makes you feel weak and tired.
Severe anemia can damage organs and lead to death.
What are the types of thalassemia?
There are two main types:
alpha and beta. Beta thalassemia is the most common.
You need both alpha- and
beta-globin to make hemoglobin. Beta thalassemia occurs when one or both of the
two genes that make beta-globin don't work or only partly work as they should.
If you have one damaged gene, you
may have mild anemia and probably won't need treatment. This is
called beta thalassemia minor or beta thalassemia trait. It happens when you get a normal gene from one
parent and a thalassemia gene from the other.
genes are damaged, it means you got a thalassemia gene from each
parent. You may have moderate or severe anemia.
If you have moderate anemia (beta thalassemia intermedia), you may need
People with severe anemia (called
beta thalassemia major or Cooley's anemia) need blood transfusions throughout life. Symptoms
of anemia usually begin within a few months after birth.
This type occurs when
one or more of the four alpha-globin genes that make hemoglobin are missing or
If one gene is missing or damaged: Your red blood cells might be smaller than normal. You will have no symptoms and you will not
need treatment. But you are a silent carrier. This means
you don't have the disease but can pass the defective gene to your child.
If two genes are missing or damaged: You will have very mild
anemia that will typically not need treatment. This is called
alpha thalassemia minor or alpha thalassemia trait.
If three genes are missing: You will have mild to moderately severe
anemia. This is sometimes called hemoglobin H disease.
If it is severe, you may need blood transfusions.
If all four genes are missing: This is called alpha thalassemia major or hydrops fetalis. The fetus will be stillborn, or the
child will die soon after birth.