Steps forward in gene therapy for hearing loss associated with Norrie Disease

3 Oct 2023, 12:02 p.m.

Image of part of the uncoiled mouse cochlea after treatment with gene therapy and in pink are the sensory hair cells which preserve hearing in mice with Norrie disease

An international team led by researchers at GOSH, UCL and the National Institute for Health and Care Research Great Ormond Street Hospital Biomedical Research Centre (NIHR GOSH BRC) have been working hard to develop a novel gene therapy in mice to reduce the hearing loss associated with Norrie disease.

Norrie disease is a life-altering genetic condition primarily affecting boys, that causes both blindness and hearing loss.

Children are born blind and often develop progressive hearing loss from around the age of 12 years, severely affecting their lives and independence.

Novel gene therapy in mice

Currently, the only available treatment option for hearing loss associated with Norrie disease is cochlear implants, which don’t fully restore hearing and have limited success in children with Norrie disease.

This leads to the sad reality where children develop dual sensory loss which impacts their everyday lives.

However, this new research is hoping to change this.

The treatment involves injecting a gene therapy which encourages cells to produce the missing norrin protein linked to Norrie disease. In doing so, researchers have been able to prevent the death of tiny hair cells in the cochlea of mice – the part of the inner ear responsible for hearing – to reduce hearing loss.

The therapy has also been shown to significantly improve the abnormal blood vessels formed in the eyes and ears of mice with the disease, resulting in both better hearing and vision after treatment.

This research was published in the medical journal, EMBO.

Potential to be "transformative"

GOSH Charity funded researcher Professor Jane Sowden has commented on the importance of this work.

"In this study we were able to reduce the progressive hearing loss in a Norrie disease model by gene therapy for the first time," she says.

"The treatment in mice was successful not only for newborns but also when we treated at a stage comparable to children and young people. This is exciting progress as it lays the groundwork for future applications in patients – this could be transformative for them and their families and carers."

A slice through a cochlea after gene therapy (green) shows replaced norrin protein in pink / magenta.

A slice through a cochlea after gene therapy (green) shows replaced norrin protein in pink / magenta.

The results of this study pave the way for an exciting new therapy for children with Norrie disease, some of whom are treated at GOSH.

This new research could help prevent deafblindness and greatly improve quality of life. However, since this work has only been shown in animal models, further research must be conducted before this treatment reaches patients.

Importance of funding

This study highlights the importance of funding research into paediatric rare diseases, which seldom attract the kind of support they really need.

GOSH Charity is committed to changing this through initiatives like our annual National Call, where researchers from across the UK are invited to apply for funding for paediatric research projects. It was through this scheme that researchers at GOSH were able to complete this study.

The research was also part funded by The Norrie Disease Foundation, a patient advocacy group who raise awareness of Norrie disease and fund research to slow its symptoms. Collaborating in this way allows us to build wider access to resources and form a larger network of scientists working towards the same goal.

By working in tandem with other organisations, we hope to fund a broad range of research opportunities and give researchers the chance to work on life-changing treatments.

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