This August, in recognition of Spinal Muscular Atrophy Awareness Month, we are highlighting some of the most recent advancements in SMA and neuromuscular disease research.
At the American Brain Foundation, the philosophy of “Cure One, Cure Many” guides our investment in research, because we know all brain diseases are interconnected. This means research discoveries for one brain disease have the potential to advance the diagnosis and treatment of other diseases. We can see some exciting examples of Cure One, Cure Many in action in the recent groundbreaking gene therapy for spinal muscular atrophy (SMA) that is now fueling similar research into other neuromuscular diseases.
Learn about some of these recent breakthroughs in diagnosing and treating SMA, and how breakthroughs in gene therapy for SMA are helping researchers make progress across other neuromuscular disease areas.
What Is Spinal Muscular Atrophy?
Neuromuscular diseases affect the peripheral nervous system, which is made up of the nerves that connect the brain and spinal cord to the rest of the body. These nerves control voluntary muscle movement and communicate sensory information to the brain. Spinal muscular atrophy (SMA) is one type of neuromuscular disease, but other common types include amyotrophic lateral sclerosis (ALS), muscular dystrophy, and myasthenia gravis.
SMA is a progressive, hereditary disease that damages and destroys nerve cells in the brain and spinal cord. When these nerves are damaged, it affects a person’s ability to move the muscles in their arms, legs, face, chest, and throat, as well as their ability to speak, walk, breathe, and swallow. Over time, the muscles weaken and decrease in mass, and a person may develop twitching in certain muscles due to the breakdown in communication between peripheral nerves and the brain.
The most common form of SMA can be classified into four types. These types—designated I through IV—are distinguished by the degree of impairment to a person’s mobility, the age of disease onset, and the severity of symptoms.
Caring for someone with SMA often involves helping to manage breathing, nutrition, movement, and daily activities. Caregivers may also organize physical and occupational therapy sessions, assist with stretching and strengthening exercises, and offer help with special ventilation equipment or assistive devices like wheelchairs and braces.
Are Any Types of SMA Treatable?
Most treatments for SMA include medications and therapies to manage symptoms and prevent complications. However, recent research led by Jerry Mendell, MD, FAAN, 2019 recipient of the American Brain Foundation’s Scientific Breakthrough Award, uncovered a one-time treatment for children with Type I SMA, developing the first cure for what is otherwise a fatal disease.
Dr. Mendell’s research used gene therapy to develop the new treatment, building on a relatively new research area. The world’s first gene therapy treatment was developed in 1990, laying the foundation for this breakthrough in SMA treatment and many others. Gene therapy now shows promise for treating a range of other diseases for which there is no other cure.
Additionally, research has improved the diagnosis of SMA by uncovering new ways to screen for the disease, in turn allowing for earlier treatment. “The diagnosis and treatment of SMA have dramatically changed over the past years through a combination of newly introduced medications and newborn screening,” says Stefan Nicolau, MD, recipient of a 2022 Next Generation Research Grant from the American Brain Foundation.
“Previously, babies with SMA were typically diagnosed around 2 to 6 months of life and the vast majority died before their second birthday,” says Dr. Nicolau. “Now, most babies are diagnosed in the first week or two of life and receive early treatment, which allows most of them to reach milestones that would never have been possible without treatment.”
How Advancements in SMA Treatment Are Fueling Other Neuromuscular Disease Research
Dr. Mendell’s model for using gene therapy to treat SMA is now helping to guide the development of similar therapies for other neuromuscular diseases, such as Duchenne and limb-girdle muscular dystrophy and ALS.
“SMA has in many ways been at the forefront of therapeutic development for inherited neuromuscular disorders,” says Dr. Nicolau.
Dr. Nicolau’s own research focuses on developing new ways to use gene therapy to correct the genetic mutations that cause Duchenne muscular dystrophy (DMD). He hopes this research will be a first step toward bringing genome editing for DMD into clinical use. Other studies are underway as well—for example, current American Brain Foundation-funded researcher, Samuel Carell, MD, PhD, is investigating applications of gene therapy for neuromuscular diseases like myotonic dystrophy (DM).
“The development of gene therapy has transformed SMA care, and there are at the moment numerous gene therapies in development for other neuromuscular disorders,” says Dr. Nicolau. “I expect that a number of these will reach clinical trials and even receive approval in the coming years.”
Advancements in the diagnosis and treatment of SMA are important because they can help researchers find more effective treatments and cures for other neuromuscular diseases. Research is the only way to make progress in detecting, treating, and curing brain disease.
In honor of Spinal Muscular Atrophy Month, we hope that you will join us as we continue to invest in this critical research. With your help, one day we will all be able to live without brain disease.
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