WHAT’S BEING CLAIMED:
- A breakthrough in gene-editing technology revealed that CRISPR can be used to treat Duchenne muscular dystrophy (DMD), a fatal genetic condition, in the future.
- DMD is a condition that involves the gradual destruction of muscles in the body.
- The symptoms of DMD include losing muscle functions such as walking, standing, or even swallowing.
Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy. A cause of this condition is the inability to use a protein called dystrophin, which acts as an adhesive that steadies muscle fiber. The myriad of conditions is often caused by a defect in a person’s genetic make-up –genetic mutations that are responsible for dystrophin and stops them from producing any at all.
DMD mostly affects boys because the dystrophin gene is carried by the X chromosome. Girls characteristically possess two X chromosomes which result in one healthy copy of the gene that carries dystrophin, although women can still be carriers of the gene and may pass it on to their male offspring.
The symptoms of DMD include losing muscle functions such as walking, standing, or even swallowing.
The initiation of the CRISPR-Cas system, which is an inexpensive gene-editing method, has raised hopes of curing DMD entirely through gene therapy. The new study that was published involved dogs since a discovery was made that dogs could be an ideal test animal because they can be born with a mutation that made them develop DMD. The mutation removes exon 50, a specific area of DNA on the dystrophin gene that codes for the protein. Without exon 50, exon 51 will also not work – making it impossible to produce dystrophin.
Four beagles were bred with DMD by researchers. They used CRISPR to edit exon 51, peppering it with errors. Theoretically, the errors would cause the body’s affected cells to skip exon 51. Favorable results would be a functional level of dystrophin production, although reduced, which is what happened after the test.
Researchers discovered that the dystrophin levels bounced back to normal in the dogs’ heart and the diaphragm at 92% and 56%, respectively, after six to eight weeks.
Researcher Leonela Amoasii at the University of Texas Southwestern Medical Center explained, “Our strategy is different from other therapeutic approaches for DMD because it edits the mutation that causes the disease and restores normal expression of the repaired dystrophin… But we have more to do before we can use this clinically.”
For instance, caution should be taken despite the positive research results, since it’s only a pilot demonstration. The dogs were also not observed long enough to ensure that the effects were sustained (the beagles were euthanized to prevent them from experiencing any potential suffering that could result from the induced treatment)
Also, people with DMD who have this particular mutation are only 15%, so several gene edits would be required to help out other sufferers worldwide. The researchers have formed the company Exonics Therapeutics, and they are willing to pursue longer-term research about the cure for DMD and other genetic conditions.