MFN2 and optic atrophy: MFN2 mutation causes typical CMT2, which is called CMT2A2, and can also present different clinical phenotypes, including hereditary motor sensory neuropathy (HMSN) with pyramidal features (HMSN V), HMSN with optic atrophy (HMSN VIA), AR‐CMT, severe early onset axonal neuropathy, early onset stroke without neuropathy, HMSN with cognitive impairment, and brain mitochondrial dysfunction (Mostacciuolo et al.,2000; Zuchner et al.,2006; Chung et al.,2008; Del Bo et al.,2008; Nicholson et al.,2008; Polke et al.,2011).