Blindness study shows how gene causes middle-age sight loss

5 September 2017

Chemical changes in the eye that can lead to blindness have been identified by a team led by former CRM researcher Dr Roly Megaw.

The findings aid the understanding of a genetic condition that causes sight loss for one in 3,000 people in the UK.

The research team examined how changes in a gene known as RPGR damage eye cells to cause a disorder known as X-linked retinitis pigmentosa. The condition is incurable and affects night and peripheral vision before gradually causing blindness in middle age.

They took skin samples from two patients and transformed stem cells, which can change into any cell type, into light-sensing eye cells known as photoreceptors. They compared these with cells from healthy relatives of the patients. Photoreceptors decay in retinitis pigmentosa patients and the researches found that the fundamental structure of the patient’s photoreceptors differed when compared with those from their family members.

Follow-up studies in mice identified key molecules that interact with the RPGR gene to maintain the structure of photoreceptors. When the RPGR gene is flawed, the photoreceptor structure is compromised and cannot function correctly, leading to sight loss.

Dr Roly Megaw, who conducted the study while based at the MRC Centre for Regenerative Medicine, said:

By furthering our understanding of the RPGR gene and its effects on photoreceptor cells, we hope our findings bring us closer to developing a possible treatment for this devastating disease.

The study is published in the journal Nature Communications. It was funded by the Wellcome Trust and the charity Retinitis Pigmentosa Fighting Blindness. Dr Roly Megaw is now an ECAT Clinical Lecturer with the University of Edinburgh’s MRC Human Genetics Unit.