Hypochromic microcytic anemia with iron overload

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What is hypochromic microcytic anemia with iron overload?

Hypochromic microcytic anemia with iron overload is a condition that impairs the normal transport of iron in cells. Iron is an essential component of hemoglobin, which is the substance that red blood cells use to carry oxygen to cells and tissues throughout the body. In this condition, red blood cells cannot access iron in the blood, so there is a decrease of red blood cell production (anemia) that is apparent at birth. The red blood cells that are produced are abnormally small (microcytic) and pale (hypochromic). Hypochromic microcytic anemia with iron overload can lead to pale skin (pallor), tiredness (fatigue), and slow growth.

In hypochromic microcytic anemia with iron overload, the iron that is not used by red blood cells accumulates in the liver, which can impair its function over time. The liver problems typically become apparent in adolescence or early adulthood.

How common is hypochromic microcytic anemia with iron overload?

Hypochromic microcytic anemia with iron overload is likely a rare disorder; at least five affected families have been reported in the scientific literature.

What genes are related to hypochromic microcytic anemia with iron overload?

Mutations in the SLC11A2 gene cause hypochromic microcytic anemia with iron overload. TheSLC11A2 gene provides instructions for making a protein called divalent metal transporter 1 (DMT1). The DMT1 protein is found in all tissues, where its primary role is to transport positively charged iron atoms (ions) within cells. In a section of the small intestine called the duodenum, the DMT1 protein is located within finger-like projections called microvilli. These projections absorb nutrients from food as it passes through the intestine and then release them into the bloodstream. In all other cells, including immature red blood cells called erythroblasts, DMT1 is located in the membrane of endosomes, which are specialized compartments that are formed at the cell surface to carry proteins and other molecules to their destinations within the cell. DMT1 transports iron from the endosomes to the cytoplasm so it can be used by the cell.

SLC11A2 gene mutations lead to reduced production of the DMT1 protein, decreased protein function, or impaired ability of the protein to get to the correct location in cells. In erythroblasts, a shortage of DMT1 protein diminishes the amount of iron transported within cells to attach to hemoglobin. As a result, the development of healthy red blood cells is impaired, leading to a shortage of these cells. In the duodenum, a shortage of DMT1 protein decreases iron absorption. To compensate, cells increase production of functional DMT1 protein, which increases iron absorption. Because the red blood cells cannot use the iron that is absorbed, it accumulates in the liver, eventually impairing liver function. The lack of involvement of other tissues in hypochromic microcytic anemia with iron overload is likely because these tissues have other ways to transport iron.

How do people inherit hypochromic microcytic anemia with iron overload?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of hypochromic microcytic anemia with iron overload?

These resources address the diagnosis or management of hypochromic microcytic anemia with iron overload and may include treatment providers.

Genetic Testing Registry: Hypochromic microcytic anemia with iron overload

You might also find information on the diagnosis or management of hypochromic microcytic anemia with iron overload in Educational resources and Patient support.

General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.

To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about hypochromic microcytic anemia with iron overload?

You may find the following resources about hypochromic microcytic anemia with iron overload helpful. These materials are written for the general public.

Additional NIH Resources - National Institutes of Health
National Heart, Lung, and Blood Institute: What is Anemia?
Educational resources - Information pages (10 links)
Patient support - For patients and families (2 links)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

Genetic Testing Registry - Repository of genetic test information (1 link)
PubMed - Recent literature
OMIM - Genetic disorder catalog

What other names do people use for hypochromic microcytic anemia with iron overload?

microcytic anemia and hepatic iron overload
microcytic anemia with liver iron overload

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about hypochromic microcytic anemia with iron overload?

Ask the Genetic and Rare Diseases Information Center

Where can I find general information about genetic conditions?

The Handbook provides basic information about genetics in clear language.

These links provide additional genetics resources that may be useful.

What glossary definitions help with understanding hypochromic microcytic anemia with iron overload?

anemia ; autosomal ; autosomal recessive ; cell ; cytoplasm ; duodenum ; endosomes ; gene ;hemoglobin ; hepatic ; hypochromic ; inherited ; intestine ; ions ; iron ; microcytic anemia ;microvilli ; oxygen ; pallor ; protein ; recessive ; red blood cell

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.

References (5 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.