Dog gene clue to eye therapy

A gene defect that is responsible for a recently identified form of progressive retinal atrophy in Swedish dogs could help to treat blindness in humans.

Scientists at Michigan State University, USA, and the University of Helsinki, Finland, has found that the MERKT (C-Mer Proto-Oncogene Tyrosine Kinase) gene defect is linked with progressive retinal atrophy (PRA) in the Swedish vallhund, a breed of dog.

PRA is linked to a form of human retinitis pigmentosa (RP), one of the most common incurable blindness worldwide.

This is the 3rd paper published in PLoS ONE by Dr András Komáromy at Michigan State University, and Professor Hannes Lohi and Dr Saija Ahonen at the University of Helsinki, Finland.

The team’s 3 papers, on Swedish vallhund and Norwegian elkhound dogs, examine blinding ocular diseases that affect both dogs and people and identified genes that cause retinal disease and glaucoma.

“The work to characterise these diseases in two Nordic dog breeds drew from well-established international collaborations between clinicians, geneticists, and dog breeders,” said Prof Lohi.

“This type of longstanding, multi-disciplinary collaboration certainly strengthens a team’s response to the challenges of unravelling complex problems and creating innovative solutions.”

Because of the similarities in ocular anatomy, canine models contribute significantly to the understanding of retinal disease mechanisms and the development of new therapies for human patients.

The larger research project, which has led to the responsible gene being identified, became possible when Dr Komáromy learned about the work that was being carried out by Prof Lohi and Dr Ahonen in Helsinki, Finland and together the team examined 324 dogs in 7 countries to identify a gene that causes the disease.

Further studies will study overexpression-related disease mechanisms in the hope that a therapeutic option with MERTK inhibitors can be found.

Ahonen S, Kaukonen M et al. A Novel Canine Retinopathy Associated with MERTK. PLoS ONE. December 2014; doi: 10.1371/journal.pone.0111941