After conducting research for the past many years, researchers have finally taken substantial step towards a possible treatment for Duchenne muscular dystrophy. With the help of new gene-editing technique, known as Crispr-Cas9, researchers have been able to cut the DNA of chromosomes at selected sites to remove or insert segments. Duchenne muscular dystrophy is a progressive muscle-wasting disease that affects boys, putting them in wheelchairs by age 10, followed by an early death from heart failure or breathing difficulties. The disease is caused by defects in a gene that encodes a protein called dystrophin, which is essential for proper muscle function.
Till now, the disease was considered incurable and common for a hereditary illness. Drugs based on chemicals known as antisense oligonucleotides, were being used to slow down the progress of the disease. A team of researchers conducted the research on mice with a defective gene that leads to Duchenne muscular dystrophy. They loaded the DNA-cutting system onto a virus that infected the mice’s muscle cells, and excised from the gene a defective stretch of DNA known as an exon. Louis M. Kunkel, a muscular dystrophy expert at Boston Children’s Hospital who discovered the dystrophin gene in 1986, the dystrophin protein anchors each muscle fiber to the membrane that encloses the muscle-fiber bundle. The dystrophin gene, which guides the protein’s production in the cell, sprawls across about 1% of the X chromosome and is the largest in the human genome.
A laboratory strain of mice has Duchenne-type muscular dystrophy in which a major part of the dystrophin protein is lost because of a mutation in the 21st exon of the gene. In 2014, Dr. Olson’s team reported that it had been able to edit out the damaged exon, enabling muscle cells to generate a functional protein. In the study published Thursday, researchers reported that they loaded the gene-editing system into a harmless virus, along with guides that directed it to cut the two ends of the 21st exon. The virus infected muscle cells throughout the mouse’s body, snipping out the exon from the dystrophin gene.
The findings seem to be significant as more than 60% of Duchenne patients have mutations in these exons.
According to the UPI, scientists used the CRISPR/Cas9 method of gene editing to correct a mutation causing Duchenne muscular dystrophy, reversing the progressive disease in the experiments with mice, according to a new study.
DMD is the most common, and severe, form of muscular dystrophy among boys. The progressive disease is caused by a mutation in the x-linked DMD gene that encodes the protein dystrophin.
"We are very encouraged by these results in animals and feel this work is an important step forward in realizing the potential of gene editing to correct disease-causing mutations in muscle tissue of patients with DMD," said Amy Wagers, a study author at Harvard University.
In other news NY Times reported, Duchenne muscular dystrophy is a progressive muscle-wasting disease that affects boys, putting them in wheelchairs by age 10, followed by an early death from heart failure or breathing difficulties. The disease is caused by defects in a gene that encodes a protein called dystrophin, which is essential for proper muscle function.
The ScienceWorldReport notes that, the health issue, which is linked to an x-linked DMD gene that encodes the protein dystrophin, was reversed when researches corrected the mutation in mice models. They did this by snipping away one of the genetic mutations thought to be responsible for the heath issue. Then, researchers found that the injected mice showed some restored muscle function.
Because the disease is devastating and incurable, and common for a hereditary illness, it has long been a target for gene therapy, though without success. An alternative treatment, drugs based on chemicals known as antisense oligonucleotides, is in clinical trials.