Background: During the first few trials of gene therapy for Leber’s hereditary optic
neuropathy performed by our group, the visual acuity of the patients increased gradually over several
months, or even years. However, in the current round of gene therapy for Leber’s hereditary optic neuropathy,
we noted that the visual acuity of three patients increased rapidly, within a few days after
Case presentation: Three patients who were diagnosed with mitochondrial gene 11778 mutation (associated
with a G-to-A transition at Mt-11778 in the ND4 subunit gene of complex I of mitochondrial
DNA that changes an arginine to histidine at amino acid 340) by genetic diagnosis were followed up
three times before gene therapy, which lasted for 1 year, without spontaneous improvement of vision.
Visual acuity in one or both eyes of each of the three patients increased rapidly after the initial gene
Conclusion: We suspect that in some patients with Leber’s hereditary optic neuropathy, a portion of
the retinal ganglion cells might remain in a “dormant” state for a certain period of time; these may be
activated, within an optimal timeframe, during gene therapy for Leber’s hereditary optic neuropathy.