According to an article from ScienceBlog, a twist on CRISPR gene editing has allowed a team of researchers to successfully treat myotonic dystrophy type 1 in mouse models. By modifying RNA rather than DNA, this team has possibly discovered a new treatment for myotonic dystrophy.
About Myotonic Dystrophy
Myotonic dystrophy is a form of muscular dystrophy that is characterized by the progressive weakening and atrophy of the muscles. There are two forms of this condition: type 1 and type 2, with the latter often resulting in less severe symptoms and affecting different muscles. Type 1 is the result of a mutated DMPK gene, while type 2 occurs due to a mutated ZNF9 gene. Common symptoms of both forms include an abnormal heart rhythm, weakness of the cardiac muscles, problems with breathing, weakness in the voluntary muscles, cataracts, learning disabilities, an inability to relax the muscles, issues swallowing, gallstones, constipation, abnormal uterus muscles, and issues with speech, vision, and hearing. There is currently no cure or treatment specific to myotonic dystrophy; treatment is symptomatic.
Gene Editing for Myotonic Dystrophy
A few years ago, a team of researchers at the University of California San Diego found that not only can CRISPR gene editing be applied to DNA but to RNA as well. They call it RNA-targeting Cas9, or RCas9 for short. This discovery has now been applied to myotonic dystrophy.
In a study published in Nature Biomedical Engineering, the researchers discovered that RCas9 has the ability to get rid of toxic RNA and reverse many of the symptoms of myotonic dystrophy in mouse models.
Using a non-infectious virus, the researchers delivered either one dose of the gene therapy or a mock treatment. The results were overwhelmingly positive; the therapy was able to clear more than half of the toxic RNA. In the end, mice with myotonic dystrophy were nearly indistinguishable from mice in good health.
While much more work needs to be done, these results are very exciting. Human trials need to be conducted in order to better understand the treatment and to ensure that it works. Research can also be conducted to see if this therapy will work for other genetic conditions, such as Huntington’s disease or ALS. Regardless of the research that still needs to be done, the results of this study are very exciting for those living with myotonic dystrophy.