Gene therapy turns the spectacle of 12 born with a rare malformation

single injection into the eye of a patient brings "results" stunning. The results may offer hope for people with macular degeneration and retinitis pigmentosa.Pennsylvania researchers using gene therapy have made significant improvements in vision in 12 patients with rare hereditary problems of vision, finding suggests that it may be possible, similar improvements in the production of larger number of patients with retinitis pigmentosa and macular degeneration.

The team last year reported success with three adult patients, a feat that was celebrated as a great success for gene therapy. They now have a patient treated nine others, including five children, and find that the best results in younger patients who reached the defective cells of the retina have not had time to die.

The youngest patient, aged 9, Corey Haas, he was considered blind before treatment began. It was essentially confined to his house and came into play, had great difficulties in navigating an obstacle course and special equipment required for the expansion books, and help in the classroom.

Today, after a single injection of a gene in one eye, he rides his bike through the neighborhood, sailing no support in the classroom, the obstacle course quickly and has even played his first game softball.

The results are "astonishing," said Stephen Rose, scientific director of the Foundation Fighting Blindness, which supports the work, but not directly involved. "The big message is that each individual had improved in the group ... And there were no security problems at all."

The study holds "great promise for the future" and "is interesting because of its simplicity," wrote researchers at the Medical Center Nijmegen in the Netherlands in an editorial on the report, published online Thursday by the Lancet.

The 12 patients had liver congenital amaurosis, about 3,000 people in the United States and perhaps 130,000 worldwide concerns. The victims were born with a severe visual impairment, until they are completely blind, mostly deteriorated in childhood or adolescence. There is no treatment.

The liver is a good candidate for gene therapy because most of the visual system is intact, especially at birth and childhood. Errors in 13 different genes are known to cause this, but all 12 patients suffered from a defect in a gene, RPE65. This gene produces a derivative of vitamin A, detection of light is essential.

About five children are born each year in the United States with the defect, which was chosen because researchers at Children's Hospital of Philadelphia and the University of Pennsylvania School of Medicine, the gene has been cloned, making copies available.

The study conducted by Dr. Katherine A. Max, Dr. Albert M. Maguire, and Dr. Jean Bennett led by these two institutions, five people have registered in the United States, five from Italy and two from Belgium. Five children were, and the 44th oldest

The good copy of the RPE65 gene in a defanged version of a human adenovirus added. The virus was subsequently developed was added to the cells of the retina and the gene into the DNA of cells.

Maguire uses a long thin needle worst use to prepare in the retina of the eye in each patient. In two weeks, the treated eyes become sensitive to light has begun, and within a few weeks ago, the vision began to improve. The patients have been younger, he says. This was expected, Bennett said, because similar results were observed in dogs and rodents.

In both objective and subjective measures, the vision that all patients improved. They could navigate an obstacle course to read the eye charts for most tasks of daily life. The improvement has been written it as long as two years.

Children who have been treated, are "now able to go play like a child with normal vision," said Maguire.

Bennett believes that the oldest patients of study, a mother was not able to walk down the street to meet their children at school are. "Now they can. It also achieved its primary objective which was shown to her daughter in a hit run away from home. "

There are clear limitations of the study. The vision of patients was not normal, because the damage was inflicted, which was already fixed on the retina, and one eye.

"The big elephant in the room: Can we treat the other eye?" Rose said.

The foundation will put more resources into research to make sure that when you go back and treat the other eye, not the removal of positive results in the light first by an immune response or other thing. "

Researchers have not optimized the dose of adenovirus also used to transport the gene into the eye. These issues are in phase 2, a larger clinical trial that is expected to begin soon be studied.

Meanwhile, the team began to treat some patients at the University of Iowa.

Researchers hope that the situation reflected in the results in other congenital conditions with different genes.

The liver is a form of retinitis pigmentosa, an estimated 100,000 Americans are affected.

The results were for macular degeneration, which affects an estimated 1.25 million Americans and is the leading cause of visual impairment in the elderly.