MARS1 and Skeletal muscle atrophy: Finally, missense mutations in KIF5A affecting the kinesin motor domain, or in MARS (SPG70) encoding the methionyl-tRNA synthase essential for protein biosynthesis (Deniziak and Barciszewski 2001), are responsible for pure (Reid et al. 2000) or complex forms of HSP with neuropathy or amyotrophy (Tessa et al. 2008; Goizet et al. 2009b; Musumeci et al. 2011; Crimella et al. 2012; Collongues et al. 2013; Novarino et al. 2014; Liu et al. 2014) but also CMT (Crimella et al. 2012; Gonzalez et al. 2013; Liu et al. 2014).