By Natania Arora
Doctors at Great Ormond Street Hospital were the first to cure blindness in children born with leber congenital amaurosis (LCA) through gene therapy. LCA is caused by a defect in the AIPL1 gene. This condition causes a large loss of vision at birth, and affects around 2 out of every 100,000 babies born every year. As stated by the NHS, the symptoms of LCA are ‘poor and declining peripheral vision (tunnel vision); night blindness; shaking eyes (nystagmus); and poor pupil reactions’.
The gene therapy works by injecting healthy copies of a malfunctioning gene into the retina at the back of the child’s eye through a keyhole surgery when they are very young. The healthy cells are inserted into an innocuous virus, allowing them to enter the retinal cells and replace the malfunctioning gene. The surgery takes around 60 minutes and afterwards, the children who have undergone the gene therapy can see shapes, play with toys, and some children can read and write, which is a significant improvement from when they could only distinguish between light and dark and were considered legally blind.
Jace was one of the people to undergo this gene therapy treatment when he was two years old. Prior to the surgery, Jace could not follow an object held in front of him with his eyes, however, after the surgery, he was able to pick things off the floor, and respond to light stimuli. An example of this is that a couple of weeks after the surgery, he was able to respond to the television and mobile phones. Furthermore, in the month following his treatment, Jace’s father noticed him squinting for the first time after seeing sunlight through the windows in their house.
The research team that led this treatment are now looking into ways to make this gene therapy treatment more accessible.
Moreover, the gene therapy for LCA is not the only gene therapy that exists and is used to treat blindness. Successful gene therapy for the RPE65 deficiency (a type of genetic blindness) has been available through the NHS since 2020.
This gene therapy has provided an effective treatment to a serious condition that affects many children across the world. This can be highlighted by Professor Michael Michaelides’, consultant retinal specialist at Moorfields Eye Hospital and professor of ophthalmology at UCL, statement to the Great Ormond Street Hospital, ‘The outcomes for these children are hugely impressive and show the power of gene therapy to change lives.’