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Sickle Cell Trait

Sickle cell trait

About 1 out of every 12 African-Americans has sickle cell trait, and about 1 out of every 100 Latinos has sickle cell trait. Sickle cell trait also affects many people whose ancestors came from Africa, Latin America, Asia, India and the Mediterranean region. However, it is possible for a person of any race or nationality to have sickle cell trait.

It is believed that sickle cell trait first appeared long ago in areas of the world where people started getting sick from malaria. Usually, a person with sickle cell trait has increased protection against malaria.

People with sickle cell trait have red blood cells that have normal hemoglobin A, and abnormal hemoglobin. The abnormal hemoglobin is called hemoglobin S. People with sickle cell trait have slightly more hemoglobin A than hemoglobin S. They have enough hemoglobin A to help their red blood cells carry oxygen to the body.

Normal hemoglobin cell
Sickle Cell Trait Cell

Normally people do not have health problems related to sickle cell trait, but under certain stressful conditions, they may have some problems. Some of these conditions include the following:

  • Dehydration – caused by lack of water in the body
  • Low oxygen – caused by strenuous exercise
  • High altitudes – causing a lack of oxygen

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

How is Sickle Cell Trait Inherited?

Sickle cell trait is inherited from one's parents, like hair color or eye color. If one parent has sickle cell trait and the other parent has normal hemoglobin, there is a 50 percent (1 in 2) chance with each pregnancy of having a child who has sickle cell trait.

Sickle Cell Trait

Why is it Important to Know if I Have Sickle Cell Trait?

Parents who have sickle cell trait can have a child with sickle cell disease. This is why it is important to understand how sickle cell trait is passed on, and how it can affect the health of your children and grandchildren.

Sickle cell disease is inherited.  If both parents have sickle cell trait there is a 25 percent (1 in 4) chance with each pregnancy of having a child with sickle cell disease. Sickle cell disease is a lifelong illness that can result in serious health problems.

Scikle Cell Trait - both parents

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)
  • Sickle beta thalassemia disease (Sβ+ or Sβ0).

To learn more about the risk of inheriting hemoglobin SC disease or Sβ thalassemia disease, please see Hemoglobin C trait and Hemoglobin Beta Thalassemia trait.