Beta Thalassemia Trait

(Also known as Beta Thalassemia Minor)

What is beta thalassemia trait?

  • Beta thalassemia affects the hemoglobin in the red blood cells.
  • All red blood cells contain hemoglobin, which carries oxygen from the lungs to all parts of the body. People with beta thalassemia do not make enough hemoglobin.
  • People with beta thalassemia trait have both normal hemoglobin A and the abnormal beta thalassemia (β) hemoglobin in their red blood cells.
  • Beta thalassemia is common in people of African, Mediterranean, Asian and Middle Eastern descent.

People with beta thalassemia trait do not have beta thalassemia disease or sickle cell disease. They cannot develop these diseases later in life. They can pass beta thalassemia trait to their children.

Why is it important to know if I have beta thalassemia trait?

Beta thalassemia trait is inherited from one’s parents, like hair or eye color. Normally, beta thalassemia trait does not cause any health problems. Beta thalassemia trait is also known as beta thalassemia minor. If one parent has beta thalassemia trait and the other parent has normal hemoglobin A, there is a 50 percent (1 in 2) chance with each pregnancy of having a child with beta thalassemia trait. These are the possible outcomes with each pregnancy.

  • 50 percent (1 in 2) chance of having a child with beta thalassemia trait
  • 50 percent (1 in 2) chance of having a child without trait
Beta Thalassemia Trait

Parents who have beta thalassemia trait can have a child with beta thalassemia disease or sickle cell disease (Sβ+ Thalassemia or Sβ0 thalassemia disease). This is why it is important to understand how beta thalassemia trait is passed on, and how it can affect the health of your children and grandchildren.

Sickle beta (Sβ) thalassemia disease

Sickle beta thalassemia disease is a type of sickle cell disease. If one parent has beta thalassemia trait and one parent has sickle cell trait, there is a 25 percent (1 in 4) chance with each pregnancy of having a child with sickle cell disease.

  • Depending on the amount of hemoglobin produced, this type of sickle cell disease is called:
    •  Sickle beta plus (Sβ+) thalassemia
    • Sickle beta zero (Sβ0) thalassemia disease.  
  • A person with sickle cell disease has red blood cells that can become “sickle or banana” shaped.
  • Under certain conditions, these cells can block circulation. This can cause cell damage and pain.Sickle cell disease is a lifelong illness that can result in serious health problems and require medical attention.
Beta Thalassemia cell

How is sickle beta thalassemia disease inherited?

People inherit beta thalassemia from their parents. If one parent has beta thalassemia trait and the other parent has sickle cell trait, there is a 25 percent (1 in 4) chance with each pregnancy of having a child with sickle cell (Sβ) disease. Sickle cell disease is a lifelong illness that can result in serious health problems. These are the possible outcomes with each pregnancy.

  • 25 percent (1 in 4) chance of having a child with beta thalassemia trait
  • 25 percent (1 in 4) chance of having a child with sickle cell trait
  • 25 percent (1 in 4) chance of having a child with Sickle beta thalassemia disease (sickle cell disease)
  • 25 percent (1 in 4) chance of having a child without trait or disease
Beta thalassemia trait, one parent sickle cell trait

Are there different types of sickle cell disease?

Yes. These are the three most common types of sickle cell disease in the United States.

  • Sickle cell anemia (also known as hemoglobin SS disease);
  • Sickle-hemoglobin C disease (also known as hemoglobin SC disease); and,
  • Sickle beta thalassemia disease (Sβ+ or Sβ0).

To learn more about the risk of inheriting hemoglobin SS disease or SC disease, please see Sickle Cell trait and Hemoglobin C trait.

Beta thalassemia disease

People with beta thalassemia trait also can have a child with beta thalassemia disease. Beta thalassemia disease is not a form of sickle cell disease, but it is a serious lifelong illness. People who have beta thalassemia disease do not make enough hemoglobin. The amount of hemoglobin a child can produce, determines whether a child has:

  • Beta Thalassemia Intermedia
  • Beta Thalassemia Major (also known as Cooley’s anemia).

What if both parents have beta thalassemia trait?

If both parents have beta thalassemia trait there is a 25 percent (1 in 4) chance with each pregnancy of having a child with Beta Thalassemia disease. Beta Thalassemia disease is a lifelong illness that can result in serious health problems. These are the possible outcomes with each pregnancy.

  • 25 percent (1 in 4) chance of having a child with beta thalassemia disease
  • 50 percent (1 in 2) chance of having a child with beta thalassemia trait
  • 25 percent (1 in 4) chance of having a child without trait or disease
Beta thalassemia trait - both parents

Review – How beta thalassemia trait, beta thalassemia disease, and sickle cell disease (Sβ thalassemia disease) are inherited

If one parent has beta thalassemia trait and the other parent has normal hemoglobin, there is a 50 percent (1 in 2) chance with each pregnancy of having a child with beta thalassemia trait.

If one parent has beta thalassemia trait and the other parent has sickle cell trait, there is a 25 percent (1 in 4) chance with each pregnancy of having a child with sickle cell disease (Sickle beta thalassemia disease). Sickle cell is a lifelong disease with serious health problems.

If both parents have beta thalassemia trait, there is a 25 percent (1 in 4) chance with each pregnancy of having a child with beta thalassemia disease. Beta thalassemia disease is a lifelong illness with serious health problems.

The only way to know if you have beta thalassemia trait is to have a simple blood test.

Talk to your physician about genetic testing and counseling if you or a member of your family member has beta thalassemia trait.