What is hemoglobin E Trait?

Hemoglobin E trait is an inherited blood disorder. That means it's passed down through your parent’s genes. It leads to an abnormal form of hemoglobin that may cause mild anemia. It occurs most often in people of Southeast Asian descent.

What causes hemoglobin E trait?

Hemoglobin E trait is caused by a gene defect. This gene defect is passed down from one of your parents. It's not a disease. It doesn't usually cause any health problems. It can cause smaller-than-normal red blood cells. When inherited from both parents, or with other abnormal hemoglobin genes, it can cause anemia and other problems.

If you inherited the defect from both parents or from one parent and a different abnormal hemoglobin from the other parent, it can cause problems, such as:

• Hemoglobin E disease.  This means you have one hemoglobin gene from each parent. This causes a slight defect in the hemoglobin beta, or HBB, gene. It results in small and irregularly-shaped red blood cells.

• Hemoglobin E/thalassemia. This means you have one hemoglobin gene from one parent, and a beta-thalassemia gene from the other parent. In this disease, the hemoglobin E causes anemia symptoms.

• Hemoglobin sickle E disease. This means you have one hemoglobin gene from one parent and a sickle cell hemoglobin gene from the other parent. This is a milder form of sickle cell anemia.  

Who is at risk for hemoglobin E trait?

Hemoglobin E trait is rare. It only occurs if you inherit the hemoglobin E defect from one of your parents. Hemoglobin E trait may occur in any part of the world. But it's most often found in people of Southeast Asian descent such as those from Thailand, Cambodia, Vietnam, or Laos.

What are the symptoms of hemoglobin E trait?

Most people have no symptoms.

Those with hemoglobin E trait plus a second abnormal hemoglobin gene (as described above), may have thalassemia, or anemia-like symptoms. Symptoms are rare but may include:

• Severe tiredness (fatigue)

• Growth failure

• Shortness of breath

• Jaundice, or a yellowing of the skin

How is hemoglobin E trait diagnosed?

Hemoglobin E trait is most often found during routine newborn screening tests. The mean corpuscular volume test might be low. This is part of the complete blood count (CBC) test. The testing might also include hemoglobin electrophoresis or iron studies. A genetic test of the HBB gene may also be done.

If you are a known carrier of hemoglobin E trait, get tested before you have children. If your partner is also a carrier, you risk having a child with hemoglobin E trait or related diseases.

How is hemoglobin E trait treated?

No treatment is usually needed for hemoglobin E. trait. If mild anemia causes symptoms, folic acid may be prescribed.

What are possible complications of hemoglobin E trait?

Some people may have problems due to anemia or related diseases.

What can I do to prevent hemoglobin E trait?

Hemoglobin E trait and related diseases are inherited. So the only thing that you can do to prevent it is not to have children with someone who's also a carrier of hemoglobin E. This is a personal decision that you'll want to talk with your partner and healthcare provider about.

How to manage hemoglobin E trait

Most people with hemoglobin E trait and hemoglobin E disease will live a healthy, normal life. Other than family planning, no other management is needed.

Key points about hemoglobin E trait

• Hemoglobin E trait an inherited blood disorder. This means it's passed down from your parents.

• Hemoglobin E trait is caused by a gene defect and is rare.

• People with hemoglobin E trait usually have no symptoms.

• Most people with hemoglobin E disease will live a healthy, normal life.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions.