In a remarkable medical breakthrough, an 11-year-old girl from North Acton, London, has become the first patient in the UK to receive a revolutionary gene therapy aimed at halting the progression of blindness caused by a rare genetic condition. Catherine L’Estrange underwent this pioneering treatment in March, which holds the potential to preserve her vision and enable her to continue enjoying her passion for reading.
A Rare Condition with Serious Implications
Catherine has been living with Bardet-Biedl syndrome (BBS), a genetic disorder diagnosed shortly after her birth. BBS affects approximately one in 100,000 births in the UK and can lead to severe vision loss, typically manifesting in late adolescence or early adulthood. In addition to impaired eyesight, individuals with BBS may experience a range of issues, including kidney dysfunction, obesity, learning difficulties, and sometimes, polydactyly—having extra fingers or toes.
The condition is caused by mutations in any one of 20 different genes, and with early diagnosis, Catherine’s family has been able to plan for her future. Reverend Timothy L’Estrange, her father, shared that they focused on fostering her independence and resilience in anticipation of her visual decline, which began with night blindness and progressed to colour blindness and loss of peripheral vision.
Innovative Treatment Procedure
The gene therapy, developed by MeiraGTx, involves a meticulous procedure where healthy copies of a specific gene are injected directly into the retina—the light-sensitive layer at the back of the eye. This treatment was previously performed on only one other patient worldwide, a 17-year-old girl from Canada.
The surgery took approximately an hour at St Helier Hospital, where surgeons carefully removed the vitreous gel within Catherine’s eye to facilitate the gene injection. According to her consultant eye surgeon, Neruban Kumaran, this innovative approach aims to save the dying retinal cells, potentially stabilising or even improving Catherine’s vision.
Catherine expressed her hopes: “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.”
Future Prospects and Ongoing Monitoring
As of now, only one of Catherine’s eyes has been treated, and the medical team is closely monitoring her progress through regular eye examinations and vision tests. Early reports from similar procedures suggest promising outcomes, with some patients noting improvements in vision, particularly in low-light conditions.
Mr Kumaran acknowledged that while the therapy may not yield perfect vision, the primary objective is to stabilise existing vision. He emphasised the importance of patience, stating, “It’s difficult to say what the ultimate results will be; it will take years to fully understand the therapy’s impact.”
Families who have seen their children receive this treatment have voiced optimism about its potential to transform lives. The parents of the Canadian patient remarked, “This treatment has given our daughter a precious chance to preserve her vision, and we hope it will become a life-changing therapy for children with BBS10 all over the world.”
Why it Matters
This pioneering gene therapy not only represents a monumental step forward in the fight against genetic blindness but also rekindles hope for families grappling with the challenges of rare genetic disorders. As medical science continues to evolve, the potential to preserve vision and improve quality of life for children affected by Bardet-Biedl syndrome and similar conditions offers a transformative promise, underscoring the importance of continued research and innovation in the field of gene therapy.
