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HJV gene

Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

HJV gene

The HJV gene provides instructions for making the protein hemojuvelin, which is critical for maintaining proper iron balance in the body.

Normal Function

The HJV gene provides instructions for making a protein called hemojuvelin. This protein is produced in the liver, heart, and skeletal muscles. Hemojuvelin plays a role in maintaining proper iron levels in the body by controlling the levels of another protein called hepcidin, which is necessary for maintaining an appropriate balance of iron (iron homeostasis).

Health Conditions Related to Genetic Changes

Hereditary hemochromatosis

More than 30 HJV gene mutations have been found to cause type 2 hemochromatosis, a form of hereditary hemochromatosis that begins during childhood or adolescence. This disorder causes the body to absorb too much iron from the diet, leading to excess iron accumulation that damages tissues and organs.

Most HJV gene mutations change one of the amino acids used to make hemojuvelin. A frequent mutation involves the replacement of glycine with valine at position 320 (Gly320Val or G320V). Other mutations create a premature stop signal, resulting in an abnormally small protein.

These mutations lead to an altered hemojuvelin protein that cannot function properly. Without adequate hemojuvelin, hepcidin levels are reduced and iron homeostasis is disturbed, resulting in iron overload.

Other Names for This Gene

  • hemochromatosis type 2 (juvenile)
  • HFE2
  • HFE2A
  • JH
  • RGM domain family, member C
  • RGMC
  • RGMC_HUMAN

Frequently Asked Questions

Children and teens may notice persistent fatigue, joint pain, darkening of the skin, abnormal liver enzymes, or growth delay. Early heart involvement can present as palpitations or shortness of breath. Any combination of these signs, especially with a family history of iron overload, should prompt iron studies.
Type 2 typically presents before age 30 with markedly high serum ferritin and transferrin saturation, often >80 %. Genetic testing that identifies pathogenic variants in the HJV gene confirms the diagnosis, whereas type 1 is usually linked to HFE mutations.
Therapeutic phlebotomy is the first‑line approach, removing 500 mL of blood weekly until ferritin falls below 50 ng/mL, then maintaining it at 50–100 ng/mL. If phlebotomy is not tolerated (e.g., anemia), iron chelators such as deferasirox or deferoxamine are used. Patients should also limit dietary iron (avoid raw shellfish, excess red meat) and vitamin C supplements that increase iron absorption.
Yes. Because type 2 hemochromatosis can manifest in early adolescence, cascade genetic testing of first‑degree relatives is recommended. If a child carries the pathogenic variant, start annual monitoring of serum ferritin, transferrin saturation, and liver function tests from age 8–10, even before symptoms appear.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.