Hemoglobin C Trait



About 1 out of every 40 African-Americans has hemoglobin C trait. This trait also affects people whose ancestors came from Italy, Greece, Africa, Latin America, and the Caribbean region.

However, it is possible for a person of any race or nationality to have hemoglobin C trait.

People with hemoglobin C trait have red blood cells that have normal hemoglobin A and an abnormal hemoglobin. The abnormal hemoglobin is called hemoglobin C. People with hemoglobin C trait have slightly more hemoglobin A than hemoglobin C. People with Hemoglobin C trait do not have health problems related to having the trait.

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


How is Hemoglobin C Trait Inherited?

Hemoglobin C trait is inherited from one's parents, like hair color or eye color. If one parent has hemoglobin C 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 hemoglobin C trait. These are the possible outcomes with each pregnancy.

Why is it Important to Know if I Have Hemoglobin C Trait?

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


Hemoglobin SC disease

Hemoglobin SC disease is a type of sickle cell disease. People who have Hemoglobin SC disease (also called sickle-hemoglobin C disease) have red blood cells that contain both hemoglobin S and hemoglobin C.

Under certain conditions, these red blood cells harden and take on a sickle (or banana) shape. Their shape and texture make it hard for these cells to flow through small blood vessels and deliver oxygen to different parts of the body. This can cause cell damage and pain.


How is Hemoglobin SC Disease Inherited?

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

Are there different types of sickle cell disease?

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

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


Hemoglobin C disease

People with hemoglobin C trait also can have a child with hemoglobin C disease. Hemoglobin C disease is not a form of sickle cell disease.

People who have hemoglobin C disease have red blood cells that contain mostly hemoglobin C. Too much hemoglobin C can reduce the number and size of red blood cells in your body, causing mild anemia. Hemoglobin C disease usually does not cause serious health problems.

How is Hemoglobin C Disease Inherited?

If both parents have hemoglobin C trait, there is a chance of having a child with hemoglobin C disease. These are the possible outcomes with each pregnancy.

Review – How Hemoglobin C Trait, Hemoglobin C Disease, and Hemoglobin SC Disease are Inherited

If one parent has hemoglobin C 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 hemoglobin C trait.

If one parent has Hemoglobin C 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 (Hemoglobin SC disease). Sickle cell is a lifelong disease that can cause serious health problems.

If both parents have hemoglobin C trait, there is a 25 percent (1 in 4) chance with each pregnancy of having a child with hemoglobin C disease. People with hemoglobin C disease usually do not have serious health problems from the disease.

The only way to know if you have hemoglobin C 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 Hemoglobin C trait.