Novel treatment found for LHON

Miami-A novel treatment for Leber’s hereditary optic neuropathy (LHON) uses a modified virus to introduce healthy genes into the mitochondria to correct the genetic defect.

No cure exists for LHON. Using experimental models, however, a team led by John Guy, MD, has shown that it is safe and effective to replace mutated genes with healthy ones and that doing so can prevent deterioration of the retinal cells that form the optic nerve. To deliver the healthy genes into the mitochondria, researchers redirected the adeno-associated virus to the mitochondria rather than to its typical target, the nucleus.

“This new approach shows the vast potential for genetic-therapy applications while helping to address a significant cause of blindness,” said Dr. Guy, a professor of ophthalmology at Bascom Palmer Eye Institute of the University of Miami Miller School of Medicine. Aging, cancer, and Parkinson’s disease also are caused by mutations in the mitochondria, he added.

This research demonstrates that when efficiently introduced into mitochondria, it is possible for normal DNA to correct a biochemical defect in cellular energy production and restore visual function. The investigators’ next steps will be to try incorporating all three genes that cause LHON into a single viral carrier. Dr. Guy hopes to receive FDA approval to inject therapeutic genes into patients who have visual loss from mitochondrial disease.

Two National Institutes of Health/National Eye Institute grants totaling $6.1 million funded this research, which began in 2007. Proceedings of the National Academy of Sciences published an article by Dr. Guy about the research on April 20. The article is available at www.pnas.org/content/early/2012/04/19/1119577109.

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