OPA1 and Parkinson disease: Congruently, the expanding spectrum of dominant and recessive mutations affecting the OPA1 protein has been reflected into a progressively larger landscape of clinical phenotypes linked to OPA1 dysfunction, including the vast catalog of the so-called DOA plus syndromes (14, 15) dominated by neurodegeneration and multisystem involvement (24), including multiple sclerosis (25, 26), Parkinsonism and dementia (18, 27), infantile Leigh syndrome (28), and cardiomyopathy (17).