Over 300 genetic causes of eye disease found in mice

Scientists have identified hundreds of new genes linked to blindness and other vision disorders in mice. Many of these genes are likely important in human vision and the results could help identify new causes of hereditary blindness in patients, according to the study published in the journal Communications Biology.

“This is extremely valuable for people with hereditary eye disease,” said Ala Moshiri, an associate professor at the University of California, Davis in the US. The whole ophthalmic community is going to start using these data,” Moshiri said.

The results are the latest to come from the International Mouse Phenotyping Consortium, of which UC Davis’ Mouse Biology Program is a founding member. The goal of the consortium is to identify a function for every gene in the mouse genome (IMPC), by creating lines of “knockout” mice that lack a single specific gene and screening them for their effects.

The researchers have previously identified a set of genes essential to life, genes linked to deafness and even those linked to hereditary bad breath. To date, they have generated more than 7,000 strains of gene-knockout mice, of which 4,364 have been characterised across 11 organ systems.

“The data being generated by the IMPC is accelerating the application of genomics in clinical medicine,” said Kent Lloyd from UC Davis. The team led by Bret Moore, resident at the UC Davis Veterinary Medical Teaching Hospital, Moshiri and colleagues combed the consortium database for genes linked to eye and vision defects. The researchers identified 347 genes, of which 86 were either well-established as involved in eye disease or were associated with vision in some way.

Three-quarters of the genes — 261 — were not previously known to cause eye disease in any species.

“In 2018, if someone has a form of hereditary blindness, we can identify the cause 50 to 75 per cent of the time,” Moshiri said.

“In the remaining cases, we know the mutation is there but we don’t know where to look. Now eye centres that do DNA sequencing can call back patients and screen them for these new genes,” he said.

While the mouse and human genomes clearly differ, most human genes have an analogous counterpart in mice. The new genetic information could also enable new therapies for hereditary eye disease, researchers said.