X-linked immunodeficiency with magnesium defect, EBV infection, and neoplasia (XMEN)
Inheritance pattern: X-linked
XMEN is seen in boys, and is characterized by CD4 T cell lymphopenia, chronic EBV infections, and lymphoproliferative disorders related to the EBV. All have decreased cytolytic function, and may have decreased antibody responses due to their low CD4 T cells. Oral magnesium supplementation has been proposed in the treatment of this condition, but it is not clear whether it is clinically helpful. Hematopoietic stem cell transplantation (HSCT) may be curative, though there is limited experience.