Hemoglobin E Trait

What is hemoglobin E trait?

Hemoglobin E trait is a change (mutation) in a gene that affects 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 E trait have hemoglobin A and hemoglobin E in their red blood cells.

A trait is different from a disease

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

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

• Hemoglobin E disease is an inherited blood disorder that causes a person to have red blood cells that contain mostly hemoglobin E. Too much hemoglobin E can reduce the number and size of red blood cells in your body, causing mild anemia. Hemoglobin E disease is not a form of sickle cell disease and usually does not cause serious health problems.
• Hemoglobin E/beta thalassemia disease is an inherited blood disorder that causes the body to make fewer red blood cells and less hemoglobin. It is a lifelong illness that can cause serious health problems. People with this disease need medical treatment.
• Sickle hemoglobin E disease (HbSE) is a type of sickle cell disease. People who have this condition have red blood cells that contain both hemoglobin S and hemoglobin E. Under certain conditions, these red blood cells take on a sickle (or banana) shape and become sticky and hard. Sickle cells can clump together and clog blood vessels. This can cause cell damage and pain. Sickle hemoglobin E disease requires ongoing medical care.

Risk factors for hemoglobin E trait

Hemoglobin E trait is rare. It is more common in people whose ancestors came from Southeast Asia, Africa, India, the Middle East, or the Mediterranean region. But it is possible for a person of any nationality or ancestry to have hemoglobin E trait.

Tests for hemoglobin E trait

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

How hemoglobin E trait is inherited 

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

Parents who have hemoglobin E trait can have a child with hemoglobin E disease or hemoglobin E/beta thalassemia. Whether a child has the blood disorder depends on genes from both parents.

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