British gene therapy treatment allows young children born blind to see for the first time

Toddlers who were born with the most severe form of childhood blindness can now see after groundbreaking gene therapy treatment at an NHS hospital.

Children with an extremely rare genetic condition can perform various tasks such as seeing shapes, finding toys, recognizing faces, and in some cases, even reading and writing.

They were born with a severe impairment to their sight due to a rare genetic deficiency that affects the AIPL1 gene.  

This condition, known as Leber Congenital Amaurosis, is a type of retinal dystrophy where babies experience rapid vision deterioration from birth, retaining only enough sight to differentiate between light and darkness.

Those born with the condition are considered legally blind and have up until the age of four to be eligible for the ‘life changing’ procedure. 

It is the first effective treatment in the world for the most severe form of childhood blindness and only takes an hour.

The simple procedure involves injecting healthy copies of the affected gene into the back of one eye to ‘kick-start’ sensitivity. 

In 2020, specialists from Moorfields and UCL Institute of Ophthalmology selected 11 children with this condition for surgeries that were conducted at Great Ormond Street Hospital.

The condition is so rare that children had to be found from across the world for the treatment, with families travelling to London from the US, Turkey and Tunisia. 

Jace, from Connecticut in the United States, had the gene therapy in London when he was just two years old.

As a young baby, his parents noticed something wasn’t right about his eyesight.

‘Around eight weeks old when babies should start looking at you and smiling, Jace wasn’t doing that yet,’ his mum DJ told the BBC.

After several visits to doctors and many tests, the family were told Jace had the ultra rare condition.

‘You never think it’s going to happen to you, of course, but there was a lot of comfort and relief to finally find out… because it gave us a way to move forward,’ Jace’s dad Brendan said.

The family were at a conference about the eye condition when they heard about the experimental trial being carried out in London.

Jace’s surgery was quick and ‘pretty easy’, his mum said, with only four tiny scars in his eye.

In the first month following treatment, Brendan noticed Jace squint for the first time on seeing bright sunshine streaming through the windows of their house.

His son’s progress has been ‘pretty amazing’.

‘Pre-surgery, we could have held up an object near his face and he wouldn’t be able to track it at all.

‘Now he’s picking things off the floor, he’s hauling out toys, doing things driven by his sight that he wouldn’t have done before.’

‘It’s really hard to undersell the impact of having a little bit of vision,’ Brendan said.

The gene therapy was only administered into one eye on four patients to overcome any potential safety issues. 

Then, another group of seven children were treated in both eyes. All 11 had meaningful responses to the treatment that brought them their sight back.

The new genetic medicine was from biotech company MeiraGTx.

‘We are incredibly excited to see the transformative effect of treatment in every one of the young children who received this genetic medicine,’ said Dr Alexandria Forbes, president and chief executive officer of MeiraGTx. 

‘The improvements demonstrated are unrivalled in treatment benefit compared to any ocular gene therapy in any IRD. These improvements extended outside the meaningful effects on vision and result in life-changing benefits in all areas of development including communication, behavior, schooling, mood, psychological benefits and social integration.’ 

Prof James Bainbridge, consultant retinal surgeon at Moorfields and professor of retinal studies at the UCL Institute of Ophthalmology said: ‘The parents describe the children gaining confidence in terms of their mobility, their independence, their ability to find their way around, also in terms of their recognition of shapes and faces and images.

‘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.’

Researchers said the new findings offer hope that children affected by both rare and more common forms of genetic blindness may in time also benefit from genetic medicine. 

Further work is being done to confirm the early study, which appears in the Lancet Medical Journal.