OPA1 and autosomal dominant optic atrophy: More than 60% of all genetically confirmed cases of DOA are caused by variants in the optic atrophy 1 gene (OPA1; 3q28-q29; OMIM 605290; 2), which encodes a ubiquitously expressed dynamin-related mitochondrial GTPase that is anchored to the inner mitochondrial membrane (IMM) (5).