RHO1-2 meganuclease gene editing MTA

We investigated the use of an in vivo genome editing strategy based on a previously successful re-engineered I-Cre homing endonucleas, which reduced serum cholesterol in vitro and in vivo by inactivating PCSK9. These meganucleases have the advantage of small size (920bp) and highly selective recognition of large sequences (22-24bp). Here, we targeted the most common autosomal dominant mutation in the rhodopsin gene (RHO) found in North Americans, p.P23H, which causes a form of the blinding eye disease, autosomal dominant retinitis pigmentosa (adRP). Our re-engineered I-CreI, cuts a 22-base pair recognition sequence encompassing the C to A transversion mutation responsible for the p.P23H RHO mutation. We call this I-CreI meganuclease RHO1-2. Here, we evaluated genome-wide specificity of RHO1-2 to determine the risk of off-target cutting beyond the WT RHO gene.