This finding was confirmed by chromosomal microarray analysis (GeneDx; Gaithersburg, MD), which identified a 71 kb deletion-arr(GRCh37) Xq21.1(77065542_77136498)x0 (NM_032121.5)-corresponding to the loss of exons 2-10 in MAGT1, consistent with XMEN disease (see Figure 1). Here, MAGT1 is linked to X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection and neoplasia.