Researchers identify genetic fault that can cause a keyhole shape in the eye

Babies with the condition ‘inherited retinal dystrophy associated with ocular coloboma’ are born with a hole in one or more parts of the eye, such as the iris or retina. Results published in the journal PNAS show that a fault in the gene known as miR-204 is responsible. 

Ocular coloboma is one of a number of developmental disorders that can cause serious visual disability. Together, they affect 1 in 4000 people in the western world.

In this study, the researchers looked at people with a coloboma (hole) in both eyes who also have sight loss due to progressive degeneration in the light-sensitive layer of the eye (the retina). Participants came from a large, 5-generation family. 

Understanding eye development

“For the first time, we’ve been able to demonstrate the importance of the miR-204 gene in the regulation of ocular development and maintenance, and of its contribution to eye disease,” said Professor Graeme Black, Strategic Director at the Manchester Centre for Genomic Medicine at Saint Mary’s Hospital and one of the study’s two principal investigators.

This discovery provides a clearer understanding of the control of early eye development

“This discovery provides a clearer understanding of the control of early eye development as well and helping to improve diagnosis for patients with this condition and possibly other inherited eye disorders.”

The study was funded in the UK by charities Fight for Sight and RP Fighting Blindness.

Dr Dolores M Conroy, Director of Research at Fight for Sight, said: “The Sight Loss and Vision Priority Setting Partnership showed that research to enable a precise genetic diagnosis is of great importance to people with inherited retinal conditions. 

“Discovering the role of miR-204 in eye development will help lead to better information for patients and their families about how they will be affected as the condition progresses. We are delighted to have co-funded this important collaboration.”