Gene-editing may bring cure for muscular dystrophy
Scientists have for the first time used gene-editing to treat Duchenne muscular dystrophy in a large mammal, BBC reports.
In a study on dogs, scientists were able to partially restore the key protein people with DMD cannot make. Children born with the degenerative disease have a genetic mutation that stops them producing dystrophin, a protein that is vital for muscle strength and function. The same disorder also occurs in many dog breeds.
The study was a collaboration between the Royal Veterinary College, in London, and the UT Southwestern Medical Center, in the US.
Results were published in journal Science.
The condition has no cure. It leads to loss of muscle function and strength and ultimately an early death.
The technique used in the study was for a genetic fault that affects about 13% of people with DMD. But experts say it could potentially be applied to the many other mutations those with the condition have.
The research team hopes in the future to test the technique in people.
Using the Crispr gene-editing tool, scientists were able to restore dystrophin in four dogs that had the most common genetic mutation seen in DMD patients, by making a single strategic cut in the faulty DNA.
This was done by injecting 1-month old dogs with two harmless viruses that edited the genome of the dog in the cells of the muscles and heart.
Within several weeks the missing protein was restored in muscle tissue throughout the body, including a 92% correction in the heart and 58% in the diaphragm, the main muscle needed for breathing.
Scientists have estimated that a 15% or greater improvement is needed to significantly help patients.
The proof-of-concept study raises hopes that Crispr can ultimately lead to more effective treatments for DMD.
Children with DMD often die either because their heart loses the strength to pump or their diaphragm becomes too weak to breathe”, said Dr Eric Olson, one of the authors, from UT Southwestern.
The lab will next conduct longer-term studies to measure whether the dystrophin levels remain stable and to ensure there are no adverse side-effects.