These range from the inability to survive past mid-gestation in MFN1, MFN2, OPA1, or DRP-1 deficient mice [90, 90, 95–97], to neurodegenerative diseases such as Charcot-Marie-Tooth syndrome and dominant optic atrophy [88, 89, 98, 99] caused by mutations in MFN2 and OPA1. This evidence concerns the gene OPA1 and autosomal dominant optic atrophy.