The variants identified in the NIPAL1 gene in two families (Table 1 and Supplemental Table 3) were intriguing because NIPAL1 is involved in magnesium channeling and studies have demonstrated that another gene involved in such channeling (MagT) is responsible for a rare primary immunodeficiency condition called “X-linked immunodeficiency with magnesium defect, EBV infection, and neoplasia” (XMEN), which predisposes carriers to uncontrolled EBV infection due to an inability to activate T-cells in response to EBV infection11. This evidence concerns the gene NIPAL1 and X-linked immunodeficiency with magnesium defect, Epstein-Barr virus infection and neoplasia.