CRISPR Gene-editing Technology Repairs Retinitis Pigmentosa in Patient-Derived Stem Cells

January 29th, 2016 by Dr. Mary Sunderland

Another CRISPR headline, another CRISPR success, another reason to be hopeful about the future of personalized treatments for blinding eye disease! I’m very happy to report that, so far, my predictions about the big breakthroughs in 2016 are coming true.

I have been writing a lot about CRISPR lately and that’s because the discoveries keep coming. With each new study, the researcher community is gaining confidence that the first CRISPR-based therapy will be able to treat an inherited blinding eye disease. Dr. Stephen Tsang, one of the lead authors of the most recent publications about CRISPR, proclaimed that “the first therapeutic use of CRISPR will be to treat an eye disease. Here we have demonstrated that the initial steps are feasible.”

The latest discovery showed that the gene editing tool, CRISPR, could repair a genetic mutation responsible for retinitis pigmentosa (RP) – an inherited degenerative eye disease that causes blindness in 1.5 million people around the world. The study Precision Medicine: Genetic Repair of Retinitis Pigmentosa in Patient-Derived Stem Cells, published in Scientific Reports, broke new ground because it was the first time that researchers were able to replace a defective gene in stem cells that were derived from a patient’s own tissue.

In the study, the researchers created stem cells from a sample of skin that was taken from a patient with retinitis pigmentosa. Specifically, the patient had an aggressive X-linked form of RP (XLRP) caused by a mutation in the retinitis pigmentosa GTPase regulator (RPGR) gene. The patient-derived stem cells still contain the disease-causing mutation, so the teams used CRISPR to repair the gene. This is the first time that this has been done, which scientists refer to as critical “proof-of-concept” data. The next step is testing if these “fixed” stem cells can be effectively transplanted into patients to restore their sight.

Dr. Tsang explained “The X-linked form of RP is an ideal candidate for a precision medicine approach because a common mutation accounts for 90% cases.”

A CRISPR-based approach to treating RP and other inherited retinal diseases is appealing because it allows researchers to target and fix each patient’s disease-causing mutation. Recently, another group used CRISPR to ablate a disease-causing mutation in a rats with retinitis pigmentosa. Researchers are working to show that a CRISPR-based approach is safe. For example, we need to be sure that there will not be any negative side effects (such as introducing unintended mutations).

CRISPR technology has not yet been approved for use in humans. But, researchers are predicting that the first clinical use of CRISPR will be for an eye disease. Inherited eye diseases are appealing for many reasons: 1) the genetic mutation(s) is often known; 2) the eyes are easy to access for surgery, and 3) any treatments can be noninvasively monitored. We can hardly wait for the next discovery.


Columbia University Medical Center and University of Iowa scientists have used a new gene-editing technology called CRISPR, to repair a genetic mutation responsible for retinitis pigmentosa (RP), an inherited condition that causes the retina to degrade and leads to blindness in at least 1.5 million cases worldwide.

Video by: Columbia University Medical Center