Single AAV-mediated mutation replacement genome editing in limited number of photoreceptors mediate marked visual restoration

Abstract

The most versatile treatment for inherited disorders is to precisely replace a mutated sequence with its wildtype counterpart, thereby "normalizing" the genome. We developed a single AAV platform that allows this in retinal neurons with combined CRISPR-Cas9 and micro-homology-mediated end-joining. In blind mice, the platform rescued ~10% of the retinal neurons, resulting in an incredible ~10,000-fold improvement in light sensitivity, equivalent to the restoration mediated by conventional gene augmentation therapy.