Columbia University researchers in the US have created an approach for the CRISPR gene editing tool to restore retinal function after damage caused by a degenerative disease called retinitis pigmentosa.
The new genome surgery technique is designed to cut-off the bad gene and replace it with a normal functioning gene in all types of patients, irrespective of their genetic profile.
A group of rare inherited genetic disorders, retinitis pigmentosa is characterised by the breakdown and loss of retinal cells, leading to loss of sight.
The autosomal dominant form of the disorder involves one mutated gene and one normal gene. The new method allowed researchers to remove the old gene and replace it with an improved type, without altering its normal function.
The team noted that the ‘ablate-and-replace’ approach can be used for creating CRISPR toolsets for all mutation types present in the same gene.
This mutation-independent feature is hoped to result in a quick and less expensive strategy for addressing difficult-to-treat dominant disorders.
When tested in mice with autosomal dominant retinitis pigmentosa, the technique is reported to have been successful in restoring the retinal function when assessed using an electroretinogram.
A gene replacement technique with an adeno-associated virus has been used along with the genome surgery tool to carry a healthy variant of the gene into the retina.
Study results have been published in the American Academy of Ophthalmology journal.
The CRISPR-based method is expected to additionally help in treating other conditions such as Huntington’s disease, Marfan syndrome and corneal dystrophies.
Expected to advance into human trials in three years, the genome surgery is set to be initially used for ophthalmological indications.