The importance of mitochondrial fusion proteins in neurons is highlighted by the fact that mutations in Mfn2 are often responsible for autosomal dominant Charcot-Marie-Tooth (CMT) disease [71, 72], which is a common peripheral neuropathy, while mutations in OPA1 are often the cause of autosomal dominant optic atrophy (ADOA) [73]. Here, MFN2 is linked to autosomal dominant optic atrophy.