CD8A and familial primary hypomagnesemia: Hypomagnesemia is also associated with the development of recurrent infections due to the role of Mg as a second messenger in T cell activation and a contributor to the cytotoxicity of natural killer (NK) cells and CD8+ T cells (Mazur et al., 2007; Li et al., 2011; Chaigne-Delalande et al., 2013).