What is sideroblastic anemia?

Sideroblastic anemia occurs when iron is not properly incorporated into red blood cells. It can develop due to a genetic condition or due to certain medical problems. “Anemia” is a general term for conditions in which healthy red blood cells have a lower than normal number or cannot carry oxygen efficiently.

This condition causes symptoms commonly associated with most types of anemia, such as fatigue and dizziness. The diagnosis of sideroblastic anemia involves blood tests to assess the characteristics of the red blood cells, and other diagnostic tests can help determine the cause.

Treatment can help improve symptoms and may help relieve the underlying cause. You may need follow-up tests to monitor the effects of your treatment and to determine if you need additional tests.

Types of sideroblastic anemia

Sideroblastic anemia can be inherited or acquired. When it is acquired, it develops due to non-genetic reasons. Each of these types contains many subtypes, as follows:

  • Inheritance: There are many types of hereditary sideroblastic anemia, with different inheritance patterns and different genetic mutations. Genetic changes that affect the production or transport of hemoglobin (which carries oxygen), iron, or certain mitochondrial proteins (found in the powerhouse of cells) can cause this condition.
  • Acquired: You can develop sideroblastic anemia due to medical conditions, nutritional deficiencies, toxins, or medications.

Most types of sideroblastic anemia have similar symptoms and can vary in severity. Treatment depends on severity and type.

sideroblastic anemia symptoms

Sideroblastic anemia can cause symptoms that progress gradually. As with most types of anemia, the effects are often vague, and they can affect your daily life.

Common symptoms include:

  • fatigue
  • energy shortage
  • pale complexion
  • bronzed skin
  • Jaundice (yellowing of the skin and whites of the eyes)
  • headache and irritability
  • dizzy
  • bloating (enlargement) caused by an enlarged spleen or liver
  • inability to concentrate

These symptoms can be bothersome, but because they are often subtle, many people may not realize they are signs of a medical problem.

when to see a doctor

Always seek medical attention if you have persistent symptoms of low energy.

In addition to the symptoms of anemia, you may also have other symptoms related to the symptoms that cause anemia.

Causes of sideroblastic anemia

Sideroblastic anemia has many different causes. These conditions interfere with the formation of hemoglobin, an iron-containing protein that binds to oxygen in red blood cells. When you inhale, hemoglobin picks up oxygen in your lungs and releases it to all the organs in your body so you can get energy.

When hemoglobin isn’t formed properly, iron builds up in red blood cells, but it’s useless. This leads to hypoxia in tissues throughout the body, which leads to many of the symptoms of sideroblastic anemia.

Causes of acquired sideroblastic anemia include:

  • cancer
  • Myelodysplastic syndrome (affects the way the bone marrow makes blood cells)
  • Vitamin B6 deficiency
  • copper deficiency
  • lead toxicity
  • Medications, including some antibiotics, chemotherapy drugs, and chelators (drugs used to remove excess metals from the body)

At least 25 different inherited gene mutations are associated with hereditary sideroblastic anemia. Many of these are X-linked mutations (present on the X chromosome) or autosomal recessive mutations (present on chromosomes other than X and Y, and the mutation must be inherited from both parents to produce the condition).

These various conditions can affect the transport of iron into hemoglobin or possibly the production of hemoglobin. Iron builds up in red blood cells, and in addition to reduced red blood cell function, iron overload can occur.

How is sideroblastic anemia diagnosed?

Usually, sideroblastic anemia does not cause the physical changes found on a physical exam. Sometimes it can cause a rapid pulse, shortness of breath, a change in skin color, or an enlarged abdomen and a palpable spleen or liver (your doctor can feel these organs by gently pressing on the abdomen).

These signs aren’t always present in sideroblastic anemia, and they’re considered nonspecific — meaning many different medical problems can cause them.

This type of anemia is diagnosed with a blood test. A complete blood count (CBC) is a common blood test that is usually part of routine workup. It is also often ordered when a person has symptoms of illness such as fatigue. A blood smear is a microscopic examination of a blood sample that can diagnose sideroblastic anemia.

If you have signs of sideroblastic anemia on blood tests, you may need additional diagnostic tests to determine the cause.

Possible CBC changes:

  • The mean corpuscular volume (MCV) can be low, which means that many red blood cells are small.
  • A low mean corpuscular hemoglobin concentration (MCHC) indicates a low level of hemoglobin per erythrocyte.
  • An increase in red blood cell distribution width (RDW) implies a difference in red blood cell size.

Blood smear: Iron deposits in red blood cells are ring-shaped. This can be detected when a blood sample is viewed under a microscope using Prussian blue staining, a dye used to detect iron.

Other tests can include:

  • Genetic testing for possible genetic causes
  • Lead levels if lead poisoning is possible
  • bone marrow sample
  • Test for vitamin B6 or copper deficiency
  • Tests to assess the presence of iron overload

If you have a medical problem that causes sideroblastic anemia, you may also have other effects related to the cause. For example, lead poisoning can cause cognitive deficits (difficulty thinking and processing information), and your doctor will also treat other effects of your condition.

Treatment of sideroblastic anemia

Treatment of sideroblastic anemia includes methods to improve the concentration of red blood cells and hemoglobin in the blood, and to treat underlying problems and side effects of treatment.

In general, alcohol and zinc may aggravate sideroblastic anemia. Anyone with this condition is advised to avoid these substances.

Some of the treatments used include:

  • Vitamin B6 intake or supplementation: This treatment is used to treat sideroblastic anemia caused by vitamin B6 deficiency, and to treat congenital sideroblastic anemia. You can get more of this vitamin by eating seafood, meat, chicken, some fruits and vegetables, and foods rich in the vitamin.
  • Copper intake: This mineral is found in shellfish, nuts, beans, and grains, or your doctor may prescribe supplements.
  • Lead chelators: Medications that combine with lead to remove it from the body can be used in people with severe lead poisoning.
  • Blood transfusion: Severe sideroblastic anemia may temporarily improve with a transfusion of healthy blood. Iron overload may be a side effect of this treatment and chelation may be required to remove excess iron.
  • Bone marrow transplant: This treatment involves suppressing the activity of the bone marrow with drugs and then transplanting stem cells by infusion.
  • Research: Vidaza (azacitidine), a drug used in chemotherapy, has been used in research trials as a potential treatment for sideroblastic anemia.


Sideroblastic anemias include all types of anemia that result in the appearance of ring sideroblasts in blood cells. These sideroblasts develop when iron in the body cannot bind to hemoglobin. This condition can cause symptoms ranging from mild to severe, such as fatigue, shortness of breath, and an enlarged spleen.

Sideroblastic anemia can be caused by inherited blood disorders, drug side effects, medical conditions, and nutritional deficiencies. The diagnosis is made if microscopic examination of the red blood cells shows ring sideroblasts. It is important to determine the cause so that treatment can begin.

Many people with sideroblastic anemia require ongoing treatment and close observation with repeated blood tests.

VigorTip words

Sideroblastic anemia is a rare type of anemia with characteristic diagnostic features. There are many causes of this type of anemia, and if you have been diagnosed with sideroblastic anemia, this diagnosis is only the first step in your medical evaluation.

Your medical team also needs to determine the underlying cause so you can start the correct treatment. You will need blood tests to monitor the effects of your treatment, and it’s also important to stay consistent with your symptoms so you can seek medical attention if your anemia recurs or gets worse.