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What Is Alpha Thalassemia?

Alpha thalassemia is an inherited blood disorder in which the body doesn't make as much alpha globin. Alpha globin is a building block of hemoglobin. Hemoglobin is the part of red blood cell (RBC) that carries oxygen throughout the body.  The decrease in alpha globin causes anemia (not enough RBCs in the body) and can lead to other medical problems.

Depending on the type of alpha thalassemia, anemia can be very mild or very severe.

What Are the Different Types of Alpha Thalassemia?

The four main types of alpha thalassemia are:

  • Alpha thalassemia carrier. A person who is a carrier has no signs or symptoms of anemia. They don’t need any special medical treatment.
  • Alpha thalassemia trait (also called alpha thalassemia minor). People with alpha thalassemia minor may have mild anemia, but usually don't need any medical treatment.
  • Hemoglobin H disease. People with hemoglobin H disease have moderate or severe anemia. Some people with hemoglobin H disease need frequent blood transfusions to help them grow and develop well. Others don’t but might need transfusions during certain times. Blood transfusions deliver healthy hemoglobin and RBCs to the body. Most kids with hemoglobin H do not have symptoms when they are born.
  • Alpha thalassemia major (also called hydrops fetalis). In the past, almost all babies with alpha thalassemia major died before or shortly after birth from complications of extreme anemia. After they're born, babies with alpha thalassemia major need frequent blood transfusions to survive.

What Are the Signs & Symptoms of Alpha Thalassemia Carrier or Trait?

People who are alpha thalassemia carriers do not have any signs or symptoms. People with alpha thalassemia  have a very mild anemia. 

What Are the Signs & Symptoms of Hemoglobin H Disease or Alpha Thalassemia Major?

Children with hemoglobin H disease and alpha thalassemia major have symptoms of anemia, such as:

  • extreme tiredness
  • pale skin
  • shortness of breath
  • a fast heartbeat
  • yellow skin and eyes (jaundice)
  • moodiness or irritability
  • slow growth
  • change in the shape of bones in the face and head

People with hemoglobin H and alpha thalassemia major also buildup extra iron in the body, either from the disease itself or from frequent blood transfusions. Extra iron can damage the heart, liver, and endocrine system.

People with alpha thalassemia may have other serious health problems, including:

  • bone deformities from changes in the bone marrow (where RBCs are made)
  • an enlarged spleen. Doctors might need to remove the spleen if it gets too big or causes pain.
  • gallstones. Doctors might need to remove the gallbladder if the stones cause pain or infection.
  • infections, especially if doctors removed the spleen (the spleen helps fight some infections)
  • diabetes from damage to the pancreas and endocrine system

What Causes Alpha Thalassemia?

Alpha thalassemia is caused by a mutation (or change) in the gene (or instructions) that controls how much alpha globin to make. Hemoglobin is made of two alpha globins and two beta globins. In alpha thalassemia, the body makes less alpha globin than beta globin because of the gene mutation. The imbalance in alpha and beta globin causes anemia and leads to the other medical problems from alpha thalassemia.

People inherit the instructions (or genes) that make alpha globin and beta globin from their parents. Alpha globins and beta globins join together to make the hemoglobin that is inside of red blood cells. Every child inherits four genes that make alpha globin: two from each parent.

Someone with alpha thalassemia has a change (or mutation) in the alpha globin gene that causes less alpha globin to be made than typical. The decrease in alpha globin causes an imbalance in the amount of alpha and beta globin. This imbalance causes anemia and the other medical problems of alpha thalassemia.

  • Someone who inherits one alpha thalassemia mutation is an alpha thalassemia carrier.
  • Someone who inherits two alpha thalassemia mutations has alpha thalassemia trait.
  • Someone who inherits three alpha thalassemia mutations has hemoglobin H disease.
  • Someone who inherits four alpha thalassemia mutations has alpha thalassemia major or hydrops fetalis.

A genetic counselor can help families understand the different ways alpha thalassemia runs in families.

How Is Alpha Thalassemia Diagnosed?

If a woman is pregnant and both parents have alpha thalassemia trait, doctors can check the fetus by:

  • chorionic villus sampling (CVS): Done about 11 weeks into pregnancy, this involves removing a tiny piece of the placenta for testing.
  • amniocentesis: Usually done about 16 weeks into the pregnancy, this involves removing a sample of the fluid that surrounds the fetus to check for signs of problems.

Infants may be diagnosed with a blood test, called a newborn screening, shortly after birth.

Older children may be diagnosed after routine blood work or after they develop signs of anemia. The blood tests might include:

How Is Alpha Thalassemia Treated?

Treatment depends on what kind of alpha thalassemia someone has.

Children with alpha thalassemia trait or who are carriers don't need treatment.

Children and adults with alpha thalassemia major need lifelong medical care that includes:

  • blood transfusions about every 2–4 weeks
  • medicines to remove extra iron from their bodies (called chelation)

Children with hemoglobin H may need blood transfusions and chelation (key-LAY-shun) but not as often as people with alpha thalassemia major.

Blood transfusions and chelation do not cure alpha thalassemia. Some people with alpha thalassemia major can be cured with a stem cell transplant. A stem cell transplant is a serious procedure with many risks. Doctors and scientists are working on developing other treatments to help people with alpha thalassemia.

How Can Parents Help Kids With Alpha Thalassemia Trait?

Be sure to tell all health care providers that your child has alpha thalassemia trait. This way, when mild anemia from alpha thalassemia trait shows up on blood tests, they'll know the cause. Sometimes the mild anemia from alpha thalassemia trait gets mistaken for iron deficiency. Ask for iron tests to be done before your child takes extra iron supplements or medicines.

You or your child may want to talk to a genetic counselor someday to understand how alpha thalassemia and other hemoglobin changes run in families.

How Can Parents Help Kids With Hemoglobin H or Alpha Thalassemia Major?

Children with hemoglobin H and alpha thalassemia major need lifelong medical care. The best way for your child to live their healthiest life is to get regular medical care, which includes transfusions and chelation when needed.

It is important to establish a health care team for your child. If you live near a Thalassemia Treatment Center, the center will help you put the team together. The team should include:

  • a hematologist (a doctor who specializes in blood disorders)
  • doctors to treat problems from iron overload, including:
    • an endocrinologist (a doctor who specializes in organs that make hormones)
    • a cardiologist (heart doctor)
    • a gastrointestinal doctor (a doctor who specializes in the digestive tract)
    • an infectious disease doctor to help treat any infections
    • a dietitian to help with meal planning and any vitamin supplements that are needed
    • a primary care doctor to help with routine care
    • a case manager (a nurse or other provider who coordinates your child's medical care)
    • a social worker to help with insurance information and your child's schooling, and to support you, your child, and your family
    • a psychologist to help caregivers and your child cope with thalassemia

What Else Should I Know?

If your child has alpha thalassemia, it can be a challenge for your family to manage the medical care and the thoughts and feelings that come with the illness. It can help to find support through:

  • your child's care team, especially the social worker or psychologist
  • other families who have a child with alpha thalassemia
  • friends and family

Help your child see the opportunities they have, not the limitations. And manage your own stress level by taking care of yourself and doing things that you enjoy.

Include siblings of the child with thalassemia. Show them that they can have a role, such as keeping their sibling company during transfusions or just being there to listen.

You also can learn more about alpha thalassemia online at:

Medically reviewed by: Corinna L. Schultz, MD
Date reviewed: March 2022