Arts & Science researchers at the University of Toronto trying to solve a rare disorder — which leaves newborns with profound hearing loss and gradually robs them of their vision — are celebrating a recent funding boost.
While the hearing loss can be alleviated with electronic “cochlear” implants, the research into Usher Syndrome type 1F (Usher 1F) indicates gene therapy may be able to correct the vision loss, says Tropepe, A&S vice-dean of research.
This research is focused on determining how specific gene mutations affect the shape and integrity of photoreceptors, the light sensing cells in the eye’s retina, says Tropepe.
“We think that in Usher 1F photoreceptors do not mature properly during development and the shape of their outer segment, the part of the cell that captures photons of light, is defective and often detaches from the rest of the cell,” he says.
“Photoreceptors naturally repair their outer segments because of the ‘wear-and-tear’ in processing light. We think we could correct the gene and piggyback on the eye’s natural ability to recreate the photoreceptor membranes to restore their shape and even regrow their outer segments.”
Scientists have identified three types of Usher Syndrome, according to the degree of hearing and vision loss, with Usher 1F being the most severe. In the United States and Canada, about four in every 100,000 newborns have Usher Syndrome, with types 1 and 2 the most common. There is currently no cure.
“Funding like the donation from the collaborative and also from Fighting Blindness Canada enables me to hire great trainees so I can start tackling this research from multiple directions in parallel,” adds Tropepe.
Time is of the essence for thousands of people born with Usher 1 and who are now gradually losing their sight, says Sari Springer, director of the collaborative, whose two nieces are among those living with the disorder.
One niece just started a master’s degree at American University in Washington, D.C. and the other is a University College London graduate and former Peace Corps volunteer with a successful career in the non-profit sector. Both are growing anxious about their advancing vision loss, says Springer, an A&S alumna who graduated in 1986 with a bachelor of arts in sociology as a member of University College.
“Vince's research is hugely important because it's focused on gene therapy and he's making enormous strides. We just need to get this across the finish line to save the sight of these young kids and adults,” says Springer.
“The science says by the time they're in their 40s or 50s they won't have any vision left. Vince is working at lightning speed to find the cure but every day that passes is another potential day of more sight loss.”
Tropepe is working with research scientist and PhD student Amanda Miles, an A&S alumna who graduated with her honours bachelor of science in cellular and molecular biology in 2014 as a member of University College.
He hopes to add up to two postdoctoral fellows, thanks to the support of the collaborative. He is also appealing for more help to speed progress.
“Really, what we need is a small team of people. When you have those sorts of resources, you can start to add to the excellent people we already have working on this,” says Tropepe, who feels there are several other promising research threads like drug treatments that may prove useful in tandem with the gene therapy.
Miles says the Usher 1F research project — which is only a few years old — started with a discussion between her, Tropepe and Andrew Emili, a former molecular genetics professor at U of T, now at Boston University.
“It’s a really great example of how the U of T research community fosters collaborative discussion,” says Miles.
U of T students living with a disability can rely on a world class network of support services, adds Springer, a lawyer who advises the University on disability issues.
“I come at it from the heart, because of my two nieces. I understand what it means to be able to succeed in university and how difficult that is without the assistance of such a highly accomplished accessibility services team.”