RESEARCHERS have found a drug treatment that can override a genetic fault that causes a severe blinding disorder.

Researchers, with funding from Fight for Sight, have shown that a new drug treatment, Ataluren, for cystic fibrosis and Duchenne muscular dystrophy can override a genetic fault that causes choroideremia.

Choroideremia is a rare inherited dystrophy caused by any number of faults in the gene (CHM gene) which encodes instructions for making an enzyme (REP1) which is important for cells throughout the body to process protein correctly, but is particularly active in the retina.

About 1 in 3 of these faults are nonsense mutations that generate a premature instruction for cells to stop assembling the protein. The loss of function caused by these mutations damages both the light-detecting photoreceptor cells of the retina and the blood vessel layer that supplies them.

Researchers have shown that treatment with Ataluren restored the function of the protein (REP1) in skin cells from a patient with choroideremia and in a zebrafish model.

Dr Mariya Moosajee, from the UCL Institute of Ophthalmology and the first author of the study which is published in Human Molecular Genetics, said Ataluren prevented the onset of retinal degeneration and significantly reduced oxidative stress and programmed cell death.

Dr Dolores M Conroy, Director of Research at Fight for Sight, said the results showed the potential for this class of drug to rescue retinal function in choroideremia and other inherited retinal dystrophies due to nonsense mutations.

“The most obvious potential is in the earlier stages when the retina is still functional and able to produce restored protein when treated,” Dr Conroy said.

“(Ataluren) has already had some success in clinical trials for other nonsense mutation-based inherited disorders. This could provide an alternative treatment to gene replacement therapy for some choroideremia patients.”

For more information, visit fightforsight.org.uk.

Picture credit: Fight for Sight website.