X-Linked Immunodeficiency with Magnesium Defect, Epstein-Barr Virus Infection and Neoplasia

**Semantic type:** Disease or Syndrome

**Definition:** An X-linked recessive condition caused by mutation(s) in the MAGT1 gene, encoding magnesium transporter protein 1. It is characterized by CD4 lymphopenia, defective T-cell activation and susceptibility to severe chronic viral infections, particularly Epstein-Barr virus (EBV), which may lead to the development of EBV-associated B-cell lymphoproliferative disorders.

**Synonyms:** - MAGT1 Deficiency - X-Linked Immunodeficiency with Magnesium Defect Epstein-Barr Virus Infection and Neoplasia - XMEN - XMEN