MFN2 and autosomal dominant optic atrophy: Incidentally, an expanding number of mutations involve other genes associated with mitochondrial dynamics, such as MFN2, encoding mitofusin 2, promoting fusion of the mitochondrial outer membrane, heterozygous mutations of which are responsible for CMT2B (OMIM 608507) or OPA1, a gene responsible for autosomal dominant optic atrophy type 1 (ADOA1), but also of a syndromic form of dominant optic atrophy with encephalopathic PEO and multiple mtDNA deletions (OMIM *605290) [176].