Retinal dystrophy in a Japanese boy harboring the mitochondrial DNA T8993G mutation

Background: Patients with the mitochondrial (mt) DNA T8993G mutation reportedly have variable neurologic manifestations. In these patients, retinal dystrophies progress from salt-and-pepper appearance to severe diffuse pigmentary retinopathy. Case: A Japanese boy harboring the mtDNA T8993G mutation had hypotonia, ataxia, and developmental delay. His lactate values in serum and cerebrospinal fluid were elevated. Magnetic resonance imaging showed symmetrical areas of T2-weighted hyperintensity in the putamen and caudate. Observations: In ophthalmological examinations, his pupils reacted sluggishly to light. The patient had mottling of the retina without pigmentation and subnormal electroretinographic responses in both fundi. No ophthalmoparesis or nystagmus was observed. Conclusion: Retinal dystrophy without pigmentation was found in a Japanese boy diagnosed with the mtDNA T8993G mutation. This is believed to be the first report of retinal manifestations in Japanese patients with this mutation. (C) 2002 Japanese Ophthalmological Society.