Gene fix helps blind boy see - October 26, 2009
A single dose of gene therapy greatly improved the vision of 12 patients with a rare, inherited visual disorder. The best results were achieved in the youngest patients, including a 9-year-old boy named Corey Haas, who was considered legally blind before the treatment began and now has the same level of light sensitivity as his normal-sighted schoolmates.
The study "holds great promise for the future" and "is appealing because of its simplicity", Frans Cremers and Rob Collin, of the Radboud University Nijmegen Medical Center in the Netherlands, wrote in a commentary accompanying the report, which was published online 24 October in the Lancet.
Leber's congenital amaurosis is an inherited eye disease characterized by severe degeneration of the retina and loss of vision in the first few months of life. The disease, which affects around 1 in 80,000 people, can be caused by mutations in 13 different genes. But all 12 of the patients in the Phase I study, led by researchers at researchers at the Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, suffered from a defective gene called RPE65, which codes for a vitamin A derivative that is essential for detecting light.
The researchers injected each patient's worse eye with a functional copy of the RPE65 gene inserted into an adenovirus vector. The investigators last year reported success with three adult patients (see 'Gene therapy treats blindness'), and now they've added an additional nine patients, including four children under the age of 11. These youngsters displayed the greatest visual recovery, presumably because their defective retinal cells did not yet have time to completely die off.
Most media accounts of the study were seeped with a human touch. "Corey Haas used to need a high schooler to accompany him on the soccer field, to point out where the ball was… Not anymore," writes the Philadelphia Inquirer. Haas can see the chalk board in class and no longer needs electronic aides, notes the Daily Mail. He's also riding his bike and reading large-print books, adds ScienceInsider. It's not just the young ones that can turn hearts. The oldest patient in the trial, a 44-year-old mother, can now watch her daughter play baseball, the LA Times reports.
Watch Haas with his parents and Stephen Rose, chief research officer of the Foundation Fighting Blindness, which supported the work, on CBS News:
Corey Haas with his parents and researchers. Image: Daniel Burke Photography
Comments
Amazing, I can understand the genetherapy can restore the function of retina cell and made them response to the light. But how can those boys, who had never saw the world during brain/consious development, still see the world properly at 10 years old? I mean, their brain may not know how to deal with the signal from retina cells.
Posted by: Techlabor | October 27, 2009 04:17 PM
We should not forget that this breakthrough was achieved through initial animal research. The original gene therapy for retinal degeneration was first tested on mice, and then in 2001 the procedure was tested in several Briards. The Briard is a breed of dog that can carry a defective RPE65 gene similar to the mutation that occurs on the same gene in LCA.
Briard breeders and owners provided much of the original impetus (and funding!) necessary for veterinary researchers to identify the disease and isolate the gene responsible for it in our dogs. Thanks to the work of these gifted veterinary opthamologists/researchers, we have a genetic test for the disease, now virtually eliminated in our breed.
Posted by: Maureen | October 27, 2009 05:42 PM
My son has Leber's and I would love to know how to get treatment for him.
Posted by: Deanna Bethea | October 28, 2009 09:33 PM