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MAGT1 gene
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Gene

MAGT1 gene

The MAGT1 gene provides instructions for a magnesium transporter protein that is critical for the activation and function of immune system T cells.

Normal Function

The MAGT1 gene provides instructions for making a protein called a magnesium transporter, which moves charged atoms (ions) of magnesium (Mg2+) into certain immune system cells called T cells. T cells recognize foreign invaders, such as viruses, bacteria, and fungi, and are then turned on (activated) to attack these invaders. Specifically, the magnesium transporter produced from the MAGT1 gene is active in CD8+ T cells, which are especially important in controlling viral infections such as the Epstein-Barr virus (EBV). These cells normally take in magnesium when they detect a foreign invader, and the magnesium is involved in activating the T cell's response.

Researchers suggest that magnesium transport may also be involved in the production of helper T cells (CD4+ T cells) in a gland called the thymus. CD4+ T cells direct and assist the functions of the immune system by influencing the activities of other immune system cells.

Health Conditions Related to Genetic Changes

X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia

At least five MAGT1 gene mutations that cause X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection, and neoplasia (typically known by the acronym XMEN) have been identified. XMEN is a disorder that affects the immune system in males, involving chronic EBV infection and an increased risk of a cancer of immune system cells called lymphoma.

  • MAGT1 gene mutations impair the magnesium transporter's function, reducing the amount of magnesium that gets into T cells.
  • This magnesium deficiency prevents the efficient activation of T cells to target EBV and other infections.
  • Uncontrolled EBV infection increases the likelihood of developing lymphoma.
  • Impaired production of CD4+ T cells resulting from abnormal magnesium transport contributes to the decreased ability to prevent infection and illness.

Autoimmune lymphoproliferative syndrome

MedlinePlus Genetics provides information about Autoimmune lymphoproliferative syndrome.

Other Names for This Gene

  • bA217H1.1
  • DKFZp564K142
  • IAP
  • implantation-associated protein
  • magnesium transporter protein 1
  • MRX95
  • oligosaccharyltransferase 3 homolog B
  • OST3B
  • PRO0756
  • XMEN

Genomic Location

The MAGT1 gene is found on the X chromosome.

Frequently Asked Questions

Yes. Because MAGT1-related XMEN is X‑linked, male relatives (brothers, maternal uncles, male cousins) have a 50% chance of inheriting the mutation if the mother is a carrier. Offer targeted genetic testing to at‑risk males and carrier testing to female relatives to guide surveillance and family planning.
Limited case reports suggest high‑dose oral magnesium (e.g., magnesium glycinate 400‑600 mg elemental Mg²⁺ daily) can modestly raise intracellular magnesium and modestly improve CD8⁺ T‑cell activation, but it does not correct the underlying transport defect. Supplementation should be done under physician supervision, monitoring serum magnesium, renal function, and gastrointestinal tolerance.
Management includes regular EBV viral load monitoring, antiviral prophylaxis is not routinely effective, but rituximab (anti‑CD20) can be considered for severe EBV‑driven lymphoproliferation. Immunoglobulin replacement therapy may reduce infection frequency, and patients should avoid intense immunosuppression when possible.
Watch for persistent, painless lymph node enlargement, unexplained night sweats, fever, weight loss, or new skin lesions. Any rapid growth of lymph nodes or systemic B‑symptoms warrants immediate imaging (CT/PET) and referral to hematology/oncology for biopsy.
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.

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