X-linked Immunodeficiency with Magnesium Defect, Epstein-Barr Virus Infection, and Neoplasia (XMEN) syndrome is due to mutations in the MAGT1 gene, leading to defective magnesium transport, impaired T-cell function, and low IgA levels​ (39)​. Here, MAGT1 is linked to Epstein-Barr virus infection.