MFN2 and autosomal dominant optic atrophy: Alterations in fission and fusion genes are associated with several neurodegenerative diseases: Mfn2 and Opa1 mutations are responsible for Charcot-Marie-Tooth (CMT) type 2A (Züchner et al., 2004) and dominant optic atrophy (DOA; Delettre et al., 2000) respectively, while Drp1 mutations have been associated with abnormal brain development (Waterham et al., 2007; Chang et al., 2010) and optic atrophy (Gerber et al., 2017).