Hemoglobin D Trait

What is hemoglobin D trait?

Hemoglobin D trait is a change (mutation) in a gene that helps make hemoglobin in red blood cells. All red blood cells contain hemoglobin. Hemoglobin is a protein that carries oxygen from the lungs to all parts of the body.

People with normal hemoglobin have only one type, hemoglobin A. People with hemoglobin D trait have hemoglobin A and hemoglobin D in their red blood cells.

A trait is different from a disease

Most people with hemoglobin D trait have no signs or symptoms of illness. The trait normally does not cause any health problems.

People with hemoglobin D trait do not have hemoglobin D disease or hemoglobin SD disease. They cannot develop the conditions later in life. But they can pass the genes for the diseases on to their children.

• Hemoglobin D disease is an inherited blood disorder that causes a person to have red blood cells that contain mostly hemoglobin D. Too much hemoglobin D can reduce the number and size of red blood cells in your body, causing mild anemia. Hemoglobin D disease is not a form of sickle cell disease and usually does not cause serious health problems.
• Hemoglobin SD disease is a type of sickle cell disease. People who have Hemoglobin SD disease (also called sickle SD disease) have red blood cells that contain both hemoglobin S and hemoglobin D. Some types of hemoglobin SD disease can cause serious health problems. The severity of the disease depends on the type of hemoglobin D.

Risk factors for hemoglobin D trait

Hemoglobin D trait is more common in people whose ancestors came from India or people of Asiatic Indian heritage. But it is possible for a person of any nationality or ancestry to have hemoglobin E trait.

Tests for hemoglobin D trait

A simple blood test can let you know if you have hemoglobin D trait. These tests are often done as part of routine newborn screening. Your doctor may suggest the test if someone in your family has hemoglobin D trait.

How hemoglobin D trait is inherited

Hemoglobin D trait runs in families. Like eye color or hair color, the genes for hemoglobin D trait are inherited, or passed from parents to children.

Parents who have hemoglobin D trait can have a child with hemoglobin D disease, hemoglobin SD disease, or hemoglobin D/beta thalassemia disease.

Whether a child has the disease depends on genes from both parents. It is important to understand how hemoglobin C trait is passed on and how it can affect the health of your children and grandchildren.

To learn more about hemoglobin D trait, talk to your doctor or genetic counselor. Your care team can give more details about your trait status and that of your child.