Notwithstanding, cellular and mouse studies suggest that CMT2D is caused by a gain-of-function in mutant GlyRS rather than GARS haploinsufficiency, or loss of canonical glycine aminoacylation or a secondary non-canonical function (Seburn et al., 2006; Nangle et al., 2007; Xie et al., 2007; Achilli et al., 2009; Motley et al., 2011). This evidence concerns the gene GARS1 and Charcot-Marie-Tooth disease type 2D.