The coincidental occurrence of OPA1 mutations and an MS‐like disorder is likely to have modulated the phenotypic manifestations of both disorders, but unlike the previously reported association of Leber hereditary optic neuropathy and MS (Harding disease), the optic neuropathy in patients with OPA1 mutations and an MS‐like disorder can be mild with a good visual prognosis. Here, OPA1 is linked to myeloid sarcoma.