US researchers report: chicks with an inherited disorder that causes them to be born blind have been injected in-ovo with healthy genes, and when the treated chicks hatched, they could see.
The gene-transfer raises high hopes for developing a treatment to restore sight in children with a similar condition, called Leber congenital amaurosis Type 1, or LCA1.
“I firmly believe this will work,” said neuroscientist Sue Semple-Rowland, the principal researcher from the University of Florida. “We’re really, really close to making it possible to treat kids with various forms of LCA with gene therapy and have them have a relatively normal life in terms of vision.”
While there is much work still to be done, she predicted a treatment for humans could come within just a few years.
The breakthrough with the chickens took 20 years of painstaking work by Semple-Rowland and her colleagues to determine what caused the birds’ blindness, to isolate the defective gene and then to figure out how to fix it.
Her lab modified a virus to carry a normal copy of the gene that is defective in the chickens, a type of Rhode Island Red. After boring tiny holes in the shells of fertilized eggs, they injected a small quantity of the virus into the neural tubes of two-day-old embryos, closed up the holes with a waxed substance and waited for them to hatch almost three weeks later.
Of seven chicks injected in-utero, six could see after hatching, said the scientists, whose research is published online Tuesday in the journal Public Library of Science-Medicine.