OPA1 and optic atrophy: Loss of function of these mitochondrial fusion proteins (caused by mutations) could lead to degenerative neurological disease (Liesa et al., 2009), such as autosomal dominant optic atrophy (DOA), which is induced by OPA1 mutation (Yu-Wai-Man et al., 2010), and Charcot-Marie-Tooth (CMT), which has a subacute onset of optic atrophy associated with central scotoma and color vision defects (Guerriero et al., 2020).