Doctors in London have become the first in the world to cure blindness in children born with a rare genetic condition using a pioneering gene therapy.
The children had leber congenital amaurosis (LCA), a severe form of retinal dystrophy that causes vision loss due to a defect in the AIPL1 gene. Those affected are legally certified as blind from birth.
But after doctors injected healthy copies of the gene into their eyes with keyhole surgery that took just 60 minutes, four children can now see shapes, find toys, recognise their parents’ faces, and in some cases, even read and write.
“The outcomes for these children are hugely impressive and show the power of gene therapy to change lives,” said Prof Michel Michaelides, a consultant retinal specialist at Moorfields Eye hospital and professor of ophthalmology at the UCL Institute of Ophthalmology.
“We have, for the first time, an effective treatment for the most severe form of childhood blindness, and a potential paradigm shift to treatment at the earliest stages of the disease.”
Four children aged between one and two from the US, Turkey and Tunisia were selected by specialists from Moorfields and UCL in 2020. The operations were carried out at London’s Great Ormond Street hospital.
Healthy copies of the AIPL1 gene, contained in a harmless virus, were injected into the retina, the light-sensitive layer of tissue at the back of the eye.
The gene is vital for the function of photoreceptors, light-sensing cells in the retina that convert light into electrical signals that the brain interprets as vision.
The therapy was only administered into one eye per patient to overcome any potential safety issues. The children were then followed up for five years. The results were published in the Lancet journal.
Prof James Bainbridge, consultant retinal surgeon at Moorfields and professor of retinal studies at UCL Institute of Ophthalmology, said children born with LCA can distinguish only light and dark, and what little sight they do have they will lose within a few years.
“Some children are even able to read and write following the intervention which is something that one would absolutely not expect in this condition, untreated.”
The parents of one of the children described the results as “pretty amazing” and said they felt “lucky” to have benefited. Their six-year-old son Jace, who was two when he was treated, can now pick tiny things up off the floor and identify toys at a distance.
Brendan and DJ, who did not wish to share their surname, travelled from Connecticut in the US for the treatment in September 2020.
“Pre-surgery, at around two years old, you could have held up any object, even a couple of inches away from Jace’s face, and he would not be able to track it,” said DJ. “It didn’t matter how bright it was, what colour it was, what shape it was.
“And now we get calls and notes home from school that he’s stealing phones out of teachers’ back pockets, which is hysterical to us.”
Brendan said he noticed a difference within the first month when his son reacted to the sun shining through a window. “He kind of pulled himself back. It wasn’t just even an eye shut, it was more of a physical reaction.
“And I remember welling up and getting really emotional because that was the first time that Jace ever had any reaction to any sort of light stimulus or anything of the sort. From there, it’s been pretty amazing.”
UCL developed the treatment using a special licence granted by the Medicines and Healthcare Regulatory Agency (MHRA) and backed by gene therapy company MeiraGTx.
Since the four children received the therapy, a further seven have been treated at Evelina London Children’s Hospital by specialists from St Thomas’ hospital, Great Ormond Street and Moorfields.
Article by:Source: Andrew Gregory Health editor
