Giving sight by therapy with genes

By the time Corey Haas was 7, the retinal disease he was born with had already stolen much of his vision. “He always clung to me or my wife,”
said Corey’s father, Ethan Haas.

The boy relied on a cane and adults to guide him, and, unable to see blackboard writing, sat in back with a teacher’s aide, large-type computer screen and materials in Braille.

Legally blind, Corey was expected eventually to lose all sight. Then, 13 months ago, after his eighth birthday, he underwent an experimental gene therapy procedure, receiving an injection in his left eye.

His vision in that eye improved quickly. Now 9, Corey plays Little League baseball, drives go-carts, navigates wooded trails near his home in Hadley, N.Y., and reads the blackboard in class. “It’s gotten, like, really better,” he said.

Experts in vision problems say that while it is unclear how many visually impaired people gene therapy could help, they consider the research promising for some types of blinding diseases, and an achievement for gene therapy, which has had many setbacks.

The study, reported in the journal Lancet, involved five children and seven adults, from Belgium, Italy and the United states, with a type of Leber’s congenital amaurosis, rare but serious congenital retinal diseases.

The researchers injected into the eyes of the patients a virus with the normal version of the gene REP65 inserted into its genome. When the virus invaded the light-sensing cells in the eye and inserted its own DNA into the cells’ DNA, the crucial human gene was included.