Improved hybrid dual recombinant aav vector systems for gene therapy

The problem is that AAV-mediated gene therapy is limited by the size of genes that can be transferred. This limitation hinders the effective treatment of diseases affecting the retina that require the transfer of large genes.

In conclusion, the invention provides an improved hybrid system of recombinant double AAV vector that enables effective gene therapy, especially genes larger than 5 Kb. The novel dual construct comprising the AP recombinogenic region overcomes the previously described problems encountered with AAV dual hybrid PA, leading to optimal expression of full-length transcripts in retinal cells. This invention is a significant improvement in the production of full-length ABCA4 mRNA in retinal cells based on said enhanced dual AAV hybrid AP system comprising this novel dual construct composed of a pair of nucleic acid sequences.