MTFMT and Leigh syndrome: Our WES analysis reveals three heterozygous nuclear variants, MTFMT, NARS2, and EARS2, mapping in genes known to cause COXPD associated with Leigh syndrome (Eichers et al., 2004; Tucker et al., 2011; Neeve et al., 2013; Simon et al., 2015; Lake et al., 2016).