11-year-old becomes first UK patient to receive novel gene therapy for rare cause of vision loss

An 11-year-old from North Acton, London has become the first patient in the UK to receive a novel gene therapy for Bardet Biedl Syndrome (BBS).

Catherine L’Estrange received treatment with the retinal gene therapy, which is manufactured by MeiraGTx, at St Helier Hospital in Sutton.

Catherine said: “If this treatment works, it will help me to carry on seeing things around me, and most of all I will be able to carry on reading books, which is one of my favourite things to do.”

BBS can be caused by mutations in more than 20 genes, with the gene therapy targeting a mutation in the BBS10 gene – which is the most common cause of the condition.

Catherine is the second patient internationally to receive the novel gene therapy, after a 17-year-old Canadian patient received the treatment at St Helier Hospital in August 2025.

Epsom and St Helier University Hospitals NHS Trust

Catherine L’Estrange, 11, after receiving gene therapy for a rare progressive form of vision loss

Catherine’s father, Reverend Timothy L’Estrange, shared that the family had previously been advised that gene therapy was unlikely to be available before Catherine lost her sight.

“We were surprised and delighted when we learned this treatment had become available, and that Catherine would be one of the first patients in the world to receive it,” he said.

“Our whole family has been so grateful for the opportunity to save Catherine’s vision – it will be absolutely life changing for her to retain any vision at all,” Timothy added.

Epsom and St Helier University Hospitals NHS Trust consultant ophthalmic surgeon, Neruban Kumaran, shared that many teams throughout the hospital group – including ophthalmology, pharmacy, and theatre teams – worked hard to offer hope to children with this rare genetic condition.

“We’re so pleased to offer this novel treatment through collaboration with Great Ormond Street Hospital and Moorfields Eye Hospital, who helped to identify eligible patients from their specialised clinics, and early positive feedback from the children and their families is very exciting and offers real hope to those affected by this condition,” he said.