Spinal Muscular Atrophy and Muscular Dystrophy

Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA) are diseases of the muscle and of the nerve cells that carry signals from the brain to the muscle. Dr. Ronald Worton, Scientific Director of the OHRI, 15 years go discovered the gene that is defective in DMD children. Since then, he has recruited a team of dynamic scientists who are in a position to translate this discovery into effective treatments for muscular dystrophy and other neuromuscular diseases. OHRI scientists in the Neuromuscular Disease Research Group have developed mouse models of muscular dystrophy and SMA, have produced some of the world's best gene-therapy "vectors" - harmless viruses - to deliver genes to muscle in a safe and effective way and are developing novel therapeutic strategies for these disorders.

Scientists in the Molecular Medicine Program recently became the first in the world to deliver a healthy copy of the mutated SMA gene into human cells using gene therapy. SMA, the leading genetic killer of infants, is caused by mutations in a gene that produces a crucial protein called survivor motor neuron, or SMN. Without sufficient amounts of this protein, nerve cells that control muscles and breathing degenerate and die. The OHRI team used a disabled adenovirus to delivery a healthy copy of the SMN1 gene into skin cells taken from patients with SMA. The researchers are now moving into mouse models of the human diseases, work that could lead to an eventual treatment, possibly even a cure, for spinal muscular atrophy. The testing of different drug compounds that may increase levels of survivor motor neuron protein in nerve cells is also underway. Other scientists within the Molecular Medicine Program are exploring the role of stem cells in the repair and regeneration of damaged muscle. The understanding and identification of disease genes involved in muscular dystrophy and spinal muscular atrophy is being carried out in collaboration with scientists in the Neuroscience Program.