Precision Medicine: Genetic Repair of Retinitis Pigmentosa in Patient-Derived Stem Cells

• DOI: 10.1038/srep19969
• Publication Date: 2016-01-27T10:32:41Z
• Authors: Alexander G. Bassuk; Andrew Zheng; Yao Li; Stephen H. Tsang; Vinit B. Mahajan
• Keywords: Gene Editing; Male; 0303 health sciences; Genetic Vectors; Induced Pluripotent Stem Cells; Genetic Therapy; RNA, Guide, CRISPR-Cas Systems; Article; 3. Good health; 03 medical and health sciences; Genes, X-Linked; Gene Order; Gene Targeting; Mutation; Humans; CRISPR-Cas Systems; Precision Medicine; Eye Proteins; Cells, Cultured; Retinitis Pigmentosa; Stem Cell Transplantation

AbstractInduced pluripotent stem cells (iPSCs) generated from patient fibroblasts could potentially be used as a source of autologous cells for transplantation in retinal disease. Patient-derived iPSCs, however, would still harbor disease-causing mutations. To generate healthy patient-derived cells, mutations might be repaired with new gene-editing technology based on the bacterial system of clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9, thereby yielding grafts that require no patient immunosuppression. We tested whether CRISPR/Cas9 could be used in patient-specific iPSCs to precisely repair an RPGR point mutation that causes X-linked retinitis pigmentosa (XLRP). Fibroblasts cultured from a skin-punch biopsy of an XLRP patient were transduced to produce iPSCs carrying the patient’s c.3070G > T mutation. The iPSCs were transduced with CRISPR guide RNAs, Cas9 endonuclease and a donor homology template. Despite the gene’s repetitive and GC-rich sequences, 13% of RPGR gene copies showed mutation correction and conversion to the wild-type allele. This is the first report using CRISPR to correct a pathogenic mutation in iPSCs derived from a patient with photoreceptor degeneration. This important proof-of-concept finding supports the development of personalized iPSC-based transplantation therapies for retinal disease.