Musante et al. described two siblings with severe intellectual disability, ataxia, speech impairment, athetosis, and aggressive behavior due to a frameshift mutation and a p.Trp13Gly mutation in the mitochondrial localization signal that the authors demonstrated to affect mitochondrial localization of the mature WARS2 protein (Musante et al., 2017). The gene discussed is WARS2; the disease is Ataxia.