Experimental gene therapy for blindness considered by FDA

Christian Guardino is one patient who benefited from an experimental gene therapy treatment to improve vision loss. Earlier this year he auditioned for the show "America's Got Talent."

Story highlights

  • Leber's congenital amaurosis causes severe visual impairment beginning in infancy
  • Luxturna gene therapy supplies a normal gene to retinal cells carrying mutations 
  • If approved, it would become the first gene therapy for the treatment of an inherited disease in the U.S.

(CNN)When her son was just 3-months-old, Elizabeth Guardino began to notice that he never responded when she smiled. Dangling a toy in front of his face, Christian did not follow it with his eyes.

"He also started to stare at the sun wide-eyed," said Guardino of Patchogue, New York. "That also shook us quite a bit."
These "triggers" sent her to get Christian's vision tested when he was 6 months old.
    The diagnosis was Leber's congenital amaurosis (LCA), a rare inherited eye disease that causes severe visual impairment beginning in infancy. Scientists have identified at least 13 different types of LCA with separate genetic causes.
    "How it was explained to me is I would have to carry a gene and so would my husband, so it's that rare of an occurrence," said Guardino. Still, there was some hopeful news that day.
    Christian had the type of LCA that would remain stable or slightl