PRPH2 and Abnormal retinal morphology: Due to an epitopic modification in the NMP carboxyl terminus (P341Q), which is not present in wildtype RDS and does not result in retinal disease or vision loss [24], the transferred Rds gene product can be detected selectively even on a normal RDS background using a monoclonal antibody (mAB 3B6) that recognizes the P341Q epitope.