OPA1 and optic nerve disorder: As OPA1 mutation carriers, they had an underlying predisposition to develop an optic neuropathy which progressed slowly over time, and all three patients developed a spinal cord syndrome.22 Unlike Patient B and Patient C who became aware of progressive visual deterioration in childhood, Patient A had an unusual late presentation in her early fifties with only a mild reduction in central vision (20/30 in both eyes).