Iron deficiency anemia occurs when there are insufficient red blood cells due to a lack of iron. In some cases, iron deficiency anemia can be genetic, as people can pass genetic variations onto their child.

The common causes of iron deficiency anemia include dietary factors, blood loss, and underlying health conditions.

When doctors diagnose iron deficiency anemia, they will confirm the cause so that they can determine the best course of treatment.

Read more to learn about the link between genetics and iron deficiency anemia.

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Blood-related genetic abnormalities can pass from a person to their child. In some cases, these abnormalities may cause iron deficiency anemia.

Doctors call this genetic form iron-refractory iron deficiency anemia (IRIDA). This rare condition stems from a deficiency of iron in the bloodstream.

The symptoms of IRIDA may appear similar to those of other forms of anemia, but they may not respond to treatments in the same way.

IRIDA is a hereditary condition that results from changes to the TMPRSS6 gene. This gene is responsible for giving the body instructions on creating a protein called matriptase-2.

Matriptase-2 helps with regulating iron in the body. Factors that affect this protein can alter the levels of iron in the body.

IRIDA has an autosomal recessive inheritance pattern, which means that both parents must have the recessive trait, and the child must receive both copies.

As each parent carries only one copy of the recessive trait, it is possible that neither will have any symptoms.

The symptoms of IRIDA are similar to those of other forms of anemia, but they tend to be mild.

Common anemia symptoms include:

  • fatigue
  • weakness
  • pale skin
  • shortness of breath
  • fast heartbeat
  • orthostatic hypertension, which causes dizziness when moving from sitting to standing
  • pica, which refers to cravings for nonfood items
  • changes to the skin, hair, or nails
  • headaches
  • difficulty concentrating

IRIDA should not interfere with a child’s growth. The Genetic and Rare Diseases Information Center (GARD) notes that growth and development in children with IRIDA are usually normal.

Confirming a diagnosis of IRIDA can take time. Doctors will first order blood tests such as a complete blood count (CBC) to check for signs of general iron deficiency anemia. They will then carry out other tests to determine the underlying cause.

If a CBC test or another specific blood test shows that the person has iron deficiency anemia, doctors will need to rule out other causes of anemia.

They may do this by testing for:

After ruling out other possible causes, doctors will look for identifying factors of IRIDA.

Some key characteristics of IRIDA include:

  • the presence of anemia throughout a person’s life
  • very low iron levels in the blood
  • low absorption of iron, including little or no response to iron supplements or intravenous iron
  • slow utilization of iron
  • a potential family history of the condition, such as other relatives with anemia or known IRIDA

If doctors suspect IRIDA in a child, they may recommend an oral iron challenge. This involves taking a blood sample, providing the child with an oral iron dose, and then taking another blood sample after about 90 minutes.

Usually, the iron levels would rise significantly after the iron dose. If they do not, this may indicate IRIDA, difficulty absorbing iron in the intestine, or chronic blood loss.

Doctors generally diagnose IRIDA in childhood, as the condition can resolve with age. As people get older, their red blood cell count can increase, eliminating their symptoms.

A doctor may recommend gene sequencing to check for the TMPRSS6 gene and confirm the diagnosis. If the tests reveal that the person does not have mutations in this gene, the doctor can look for other inherited causes.

Although doctors may treat anemia with iron supplementation, IRIDA is iron-refractory. This means that there is a partial response to treatment, so high-dose iron treatments are necessary.

Doctors will still start by recommending oral supplements, but they will advise taking these alongside other ingredients, such as vitamin C, to boost iron uptake.

Research from 2019 found that 10 weeks of iron and vitamin C supplementation was enough to lead to significantly improved iron levels in children with IRIDA.

If oral supplements do not improve anemia, the person may need to receive regular infusions with intravenous iron.

Regular infusions can help improve anemia and iron stores, but if a person discontinues these infusions, the iron levels may drop down again and cause anemia.

The GARD notes that red blood cells often increase on their own in adulthood. In adults with IRIDA, anemia may no longer be a problem, and the person may not require treatment.

To diagnose and treat IRIDA, doctors will need to rule out other causes of iron deficiency anemia. This condition has various possible causes, including:

  • low dietary iron intake
  • bleeding from heavy menstrual periods
  • pregnancy
  • endometriosis
  • chronic internal blood loss, such as blood loss from an ulcer or colon cancer
  • inability to absorb iron from underlying conditions, such as celiac disease
  • medications that interfere with digestion or iron absorption, such as proton pump inhibitors (PPIs) and histamine-2 receptor antagonists
  • medications or interactions that cause bleeding, such as warfarin

IRIDA is not the only type of inheritable anemia.

Other genetic conditions that affect the blood may lead to other types of anemia or red blood cell conditions. Examples of these genetic conditions include:

  • Thalassemia: This condition affects the body’s ability to make hemoglobin and red blood cells.
  • Sickle cell anemia: This condition causes the red blood cells to become misshapen and clump together.
  • Fanconi anemia: This type of anemia stems from a blood disorder that prevents the bone marrow from making enough new healthy blood cells.
  • Congenital pernicious anemia: This genetic type of pernicious anemia is linked to a deficiency in vitamin B12 and an inability to absorb the vitamin.
  • Hereditary spherocytosis: This condition causes the body to create abnormal red blood cells that cannot flow as easily as normal cells and get destroyed, causing anemia.
  • Thrombotic thrombocytopenic purpura: This rare blood disorder can cause small clots to form in the blood vessels throughout the body.

Anyone who suspects that they or a child has signs of anemia should consult a doctor. A diagnosis takes time, and it is preferable to detect anemia at an early stage and begin treatment before any severe symptoms appear.

Anyone with a diagnosis of anemia who feels as though they are not responding to treatment should also consult a doctor. There may be other underlying causes to consider or other treatment options.

IRIDA is a form of genetic anemia. Genetic mutations can cause changes in how the blood utilizes iron, leading to anemia.

Doctors will still want to explore other possible causes to rule out issues such as dietary factors, blood loss, or other underlying health conditions.

IRIDA may require more intense or regular treatment with iron if the body does not respond to initial supplementation. Anyone who suspects that they have anemia or are not responding to anemia treatment should consult a doctor.