“This discovery has the potential to fast-track a cure for this disease,” says lead investigator Dr. Robert Koenekoop, director of the McGill Ocular Genetics Centre at the McGill University Health Centre (MUHC). “Our main research goal is to identify all the genes responsible for congenital blindness in children and then study them so that we can then use gene therapy to rescue their vision.”
The researchers used a new technique called SNP (single nucleotide polymorphism) technology to identify homozygous regions in the genome, which led to the discovery of the new gene called LCA5. In the past, large families were necessary to find genes, but in this study only samples from one Quebec and one American patient were used to accomplish this.
The SNP micro array technology accelerated the process of locating the gene and enabled the investigators to isolate it within a few months instead of several years. “This method may become a model for identifying other retinal diseases and causes of blindness in the future,” says Dr. Koenekoop.
The same international research team identified the CEP290 gene last year, the most common genetic cause of LCA . By using the protein structure of CEP290, the investigators were able to discover LCA5, as they have similar structures and functions in the retina. Both the CEP290 and LCA5 genes encode proteins with vital functions in the cilium of the photoreceptors, transporting visual proteins to the compartment where vision occurs. When these genes are mutated, which occurs in about 25 to 30 per cent of blind children, the visual proteins are not transported properly to the outer segments, causing the photoreceptors to stop working and die.
MEDICA.de; Source: McGill University Health Centre