Variable retinal and neurologic manifestations in patients harboring the mitochondrial DNA 8993 mutation.

Objective: Ophthalmologic and neurologic manifestations of the mitochondrial DNA mutation at position 8993 (MTATP*NARP8993) are reported and compared with previously published reports of patients with the 8993 mutation and other mitochondrial disorders.
Design: Pedigree analysis.
Setting: University referral center.
Patients: Eight subjects from two unrelated pedigrees that were positive for the mitochondrial DNA replacement mutation at nucleotide position 8993 were evaluated ophthalmologically and neurologically.
Results: Retinal abnormalities ranged from mild salt-and-pepper changes to severe retinitis pigmentosa-like changes with maculopathy. Neurologic manifestations were also highly variable and ranged from migraine headaches to severe dementia and Leigh's disease.
Conclusions: The type and extent of retinal pigmentary changes and neurologic findings varied substantially, even among members of the same family. These changes, although not specific for the MTATP*NARP8993 mutation, are highly suggestive of mitochondrial disease.