Genetic ‘Editing’ Technique Results in the First Effective Form of Treatment for Duchenne Muscular Dystrophy
Patients with Duchenne muscular dystrophy could benefit from a unique genetic ‘editing’ technique which repairs the faulty gene safely.
Biomedical engineers at Duke University, using cell samples from Duchenne patients, conducted further research into this disease by, for the first time, developing a way to transform the existing mutated gene into a functioning one. These researchers believe that this new method should replace the traditional approach of common gene therapy, which adds new genetic material to ‘override’ the faulty gene, as it is safer for patients.
This study, published in the journal of Molecular Therapy, with Duchenne muscular dystrophy patients was possible through new technology which builds synthetic proteins known as transcription activator-like effector nucleases (TALENs). These are artificial enzymes which can be used to bind to or alter a variety of genetic sequences.
The mutation in a defective gene is rectified as a result of these TALENs binding to the relevant part of an individual’s DNA. It is hoped that this genetic ‘editing’ technique can also be used for treating other diseases with genetic mutations like sickle cell anaemia and haemophilia.
Assistant professor of biomedical engineering at Duke’s Pratt School of Engineering and member of Duke's Institute for Genome Sciences and Policy,Charles Gersbach, commented on the novel approach of this gene therapy as he said, “Conventional genetic approaches to treating the disease involve adding normal genes to compensate for the mutated genes.
However, this can cause other unforeseen problems, or the beneficial effect does not always last very long. There is currently no effective treatment for this disease. Patients usually are in a wheelchair by the age of ten and many die in their late teens or early twenties.”
About one in 3,600 newborn males are affected by Duchenne muscular dystrophy, a common inherited disease. They are unable to produce dystrophin, a protein which is essential in maintaining the structural strength of muscle fibres. Patients with this disorder suffer muscle deterioration which gradually leads to paralysis and then death, at a young age of 25.
But this genetic technique could be the game changer for this disease as Duke biomedical engineering graduate David Ousterout said, “Previous studies indicate that restoring the production of dystrophin proteins will be highly functional and alleviate disease symptoms when expressed in skeletal muscle tissue. Our approach actually repairs the faulty gene, which is a lot simpler. It finds the faulty gene, and fixes it so it can start producing a functional protein again.”
Following the success of this study, these researchers are currently carrying out additional tests of this approach by using animal models of the disease.