Sideroblastic anemia refers to a rare type of anemia in which a person’s iron levels remain high. If a person has sideroblastic anemia, their bone marrow does not use iron in the usual way when it makes red blood cells.

Anemia develops when a person’s blood does not produce enough healthy red blood cells. There are several different types of anemia, such as iron deficiency anemia, autoimmune hemolytic anemia, and sideroblastic anemia.

Researchers do not know exactly how many people sideroblastic anemia affects due to scarcity of data about the condition. However, researchers define rare diseases as those that affect fewer than 200,000 people in the United States.

This article reviews what sideroblastic anemia is and its symptoms, causes, diagnosis, and treatment.

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Sideroblastic anemia occurs due to the body abnormally using iron during red blood cell production, which starts in the bone marrow.

Red blood cells are one of the main components of blood. They need iron to make hemoglobin, which is a protein that helps carry oxygen around the body. Typically, a person’s bone marrow produces immature red blood cells that contain the correct amount of iron and hemoglobin to grow into healthy mature red blood cells.

However, if a person has sideroblastic anemia, their body cannot use the iron. This means the red blood cells do not make enough hemoglobin to carry oxygen throughout the body.

Additionally, it means that iron builds up in the bone marrow and creates abnormal cells that healthcare professionals call ring sideroblasts. These are immature red blood cells that have rings of iron around their nucleus, which is in the center of the cell.

The iron rings indicate that the cells are storing iron instead of using it. This can lead to excess iron in the body, which in turn can cause iron overload. This condition results in some of the symptoms a person with sideroblastic anemia may experience.

Sideroblastic anemia causes several similar symptoms to more common forms of anemia. They may include:

A person may also experience changes to their skin color. They may appear more pale than usual, while others may have skin that appears a more bronze color due to excessive iron buildup.

Some people also experience diabetes and deafness as a result of certain forms of hereditary, or genetic, sideroblastic anemia.

There are two types of sideroblastic anemia: Genetic and acquired.


Genetic sideroblastic anemia typically occurs in early childhood or infancy and it is less common than acquired sideroblastic anemia.

This form of the condition occurs due to a mutation, or change, to one of several different X-linked or autosomal genes. The most common cause of sideroblastic anemia is a mutation of an X-linked gene, which refers to a gene linked to the X chromosome.

X-linked and autosomal genes help control heme production and other biological processes within cells. Heme contains iron, and it is a component in hemoglobin.


Acquired sideroblastic anemia may occur due to a variety of causes. It often happens in adulthood.

The most common cause of acquired sideroblastic anemia is myelodysplastic syndrome, which is a group of cancers involving bone marrow and blood cells. Myelodysplastic syndrome can cause genetic mutations that lead to sideroblastic anemia.

Other less common causes of acquired sideroblastic anemia include:

  • toxins, such as ethanol or lead
  • exposure to drugs, such as:
    • chloramphenicol
    • cycloserine
    • isoniazid
    • linezolid
    • pyrazinamide
  • vitamin B6 or copper deficiency

A doctor may order the following diagnostic tests to find out if someone has sideroblastic anemia:

The presence of ring sideroblasts in the bone marrow can help confirm diagnosis. High levels of iron can also help healthcare professionals rule out iron deficiency anemia.

When doctors examine the bone marrow, they may be able to determine what type of sideroblastic anemia a person has. They may also conduct genetic testing to determine the underlying cause of the anemia.

When a person first speaks with their doctor about their symptoms, they may assume that the symptoms are due to iron deficiency anemia, which is a more common condition.

If a person does not respond to treatments for iron deficiency anemia or notices worsening symptoms, they should contact their doctor.

Treatment options can vary according to the underlying cause of a person’s sideroblastic anemia.

Common treatments include:

  • vitamin or mineral supplementation
  • stopping exposure to substances that cause the condition, such as certain toxins
  • taking the medication recombinant erythropoietin

People who have acquired sideroblastic anemia due to exposure to a toxin or other substances generally have a good outlook once the toxins or any drugs causing the condition are no longer in their system.

A person who has genetic sideroblastic anemia may respond well to oral pyridoxine and iron overload management, which can involve phlebotomy. This is a treatment in which a healthcare professional removes iron-rich blood from the body.

Sideroblastic anemia is a rare form of anemia in which the bone marrow does not use iron properly to form healthy red blood cells. The condition may lead to fatigue and other symptoms. It can also cause iron overload.

The condition may be genetic from birth or acquired in adulthood as a result of myelodysplastic syndrome and other causes. Diagnosis will typically require several tests, such as blood tests, bone marrow examination, and genetic testing.

Common treatments involve stopping the intake of any substance causing the condition or taking medication or supplements. A person should speak with a healthcare professional for further information on an individual basis.