In the not-too-distant past, the prognosis for patients affected with an inherited retinal disorder was grim. Patients were often told that there was nothing that could be performed and that their fate was irreversible blindness. Fortunately, with developments in stem cell and gene transfer technologies there is now realistic hope for treating many of these individuals. The ability to accurately identify a patient’s disease-causing mutations is a prerequisite to the development of both gene-based and autologous cell-based therapies.
Disease-specific phenotypes identified would be used to test and confirm the efficacy of gene transfer and genome editing approaches. Gene transfer vectors shown to be effective at correcting the disease phenotype would then be used to treat patients’ remaining photoreceptor cells.
For an inherited retinal disease, it is important to direct the appropriate level of expression in the cell type specific to the pathophysiology of the disease. Thus, developing a “molecular toolbox” of gene transfer reagents is of great interest. This array of reagents would include promoters specific to heterologous cell or tissue types with varying degrees of expressivity and a series of viral vectors with a range of carrying capacities.