scales of magt1 gene: novel mutations, different presentations

Loss-of-function mutations in magnesium transporter 1 (magt1) gene cause x-linked magnesium deficiency with epstein–barr virus (ebv) infection and neoplasm (x-men), a disease with quite diverse clinical and immunological consequences. the phenotypic characteristics of the initially described patients included cd4+ t cell lymphopenia, immune deficiency, ebv viremia, and ebv-related lymphoproliferative disease. to date, a total of 25 patients have been reported. the spectrum of the magt1 defect ranges from other viral infections (hsv, vzv, cmv, mcv) and sinopulmonary bacterial infections, autoimmune diseases, non-ebv driven lymphoproliferative disease, castleman disease, hhv8+ kaposi's sarcoma, vasculitis (kawasaki) to glycosylation defects in new patients. here, we report 2 patients from two different families with novel magt1 mutations and different clinical features. the first patient presented with b cell lymphoma and low igm level without recurrent infections. the second patient presented with recurrent upper respiratory tract infections, kawasaki-like disease, hypogammaglobulinemia, and t cell lymphopenia. x-men disease is the first phenotype identified due to magt1 mutation. the identification of new mutations and atypical presentations will clarify whether there is a relationship between the genotype and the phenotype and the characteristics of the disease.