The Genetics of Blindness
Treatment for the most common inherited cause of blindness, retinitis pigmentosa, is one step closer, according to investigators at the Research Institute of the McGill University Health Centre (MUHC). They are the first to link two new gene mutations in two French-Canadian families to loss of vision in humans. Their findings are published in this month's issue of the American Journal of Ophthalmology. This project was funded by the Canadian Institutes of Health Research (CIHR), le Fonds de la recherche en santé du Québec (FRSQ) and the Foundation Fighting Blindness - Canada.
Approximately 1.5 million people worldwide are affected by retinitis pigmentosa, which at the moment has no cure. This disease causes vision loss by progressive degeneration and death of the cells that make up the retina, the portion of the eye that responds to light.
"Retinitis pigmentosa is a devastating and complex disease," says principal investigator, Dr. Robert Koenekoop, director of pediatric ophthalmology at the Montreal Children's Hospital of the MUHC. "Many genes, gene mutations and symptoms are involved. The first steps to developing a treatment are the characterization of all these factors. Important progress has been made by identifying two important gene mutations present in the French-Canadian population."
Koenekoop in collaboration with MUHC geneticist, Dr. Guy Rouleau, examined two very large French-Canadian families afflicted with retinitis pigmentosa for four generations. Ophthalmic evaluations and genetic analysis were used to characterize the gene mutations and the resulting phenotype. They demonstrated that these mutations resulted in variable, severe forms of the disease and in some cases other neurological disorders, such as hearing loss.
"Our findings show that different gene mutations result in different symptoms of the disease," says Rouleau. "Our study will provide hope to those families who have suffered from this disease for generations and will lead to new screening and diagnostic tests."
"We were fortunate to have the facilities and expertise to make this discovery," concludes Koenekoop. "This project was an excellent example of genetic and ophthalmic cross-disciplinary research."
About the Research Institute of the McGill University Health Centre
The Research Institute of the McGill University Health Centre (MUHC), located in Montreal, Quebec, is Canada's largest concentration of biomedical and health-care researchers. The institute has over 500 researchers, nearly 650 graduate and post-doctoral students and 306 laboratories devoted to research. The mission of the institute is to facilitate investigator-initiated and discovery-driven research that creates new knowledge. This research is inextricably linked to clinical programs, which provide a bench-to-bedside-to-community continuum. The MUHC research institute is renowned as a world-class research institution that operates at the forefront of new knowledge, innovation, trends, and technologies.
About the Canadian Institutes of Health Research
CIHR is Canada's premier agency for health research. Its objective is to excel, according to internationally accepted standards of scientific excellence, in the creation of new knowledge and its translation into improved health for Canadians, more effective health services and products, and a strengthened health care system.