Spinal Muscular Atrophy (SMA)

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Spinal Muscular Atrophy (SMA)

Leaders in Life-Changing Care & Research


Smiling boy with spinal muscular atrophy in a wheelchair.

Spinal muscular atrophy (SMA) is a genetic condition that causes muscle weakness and atrophy (when muscles get smaller). The disease often starts in the muscles of the back, making it hard for children to stand up and walk. It can begin to affect other parts of the body too, causing other muscles to grow weak and shrink. At Nemours, our neurologists and other specialists provide expert care for kids with spinal muscular atrophy.

We’re also involved in innovative research that’s led to a true breakthrough in SMA treatment. Nemours Children's Hospital in Orlando was one of only four locations in the world to participate in a landmark study — the first targeted drug trial for SMA. Research showed that a new treatment can slow the effects of SMA, improve kids’ survival and, in some cases, remarkably improve their muscle function. So, some children with SMA type 1 who may have struggled to move around before may now have the hope of sitting, rolling over and standing.

Learn More About Spinal Muscular Atrophy

SMA Types We Treat

SMA Types We Treat


There are four types of SMA that are based on how severe the symptoms are and when they begin. Generally, the longer it takes for symptoms to show, the less severe the disease will be.

  • SMA type 1 (also called “Werdnig-Hoffmann disease”) is the most severe, with symptoms starting between birth and 6 months of age.
  • SMA type 2 (also called “chronic infantile SMA”) has more moderate symptoms, which start at 6 to 18 months old. Infants can sit but not walk.
  • SMA type 3 (also called “Kugelberg Welander disease” or “juvenile spinal muscular atrophy”) has the mildest symptoms, which can start between 18 months and the teen years. Children can walk, but they may fall a lot and may have weak arms and legs.
  • SMA type 4 develops more slowly, with symptoms usually starting after age 35.
SMA Services We Offer

SMA Services We Offer


We offer a complete range of diagnostic and treatment options for children with spinal muscular atrophy. Our services, which may vary depending on the location you visit and the doctor your child sees, may include expert team care in:

We work together to give your child coordinated treatment to make it easier for you to see multiple specialists in a single visit.

Why Choose Us for SMA

Why Choose Us for SMA


Until recently, there was no truly effective treatment option for the most severe form of SMA (SMA type 1). But in 2016, researchers had a breakthrough — allowing some kids to live longer and reach more developmental milestones. Nemours was at the forefront of the science that led to this discovery. A medication called Nusinersen (or Spinraza™) increases the amount of protein the body needs from a missing gene. And that means improvement in kids’ breathing, motor function and survival.

From diagnosis through treatment, at Nemours we’re dedicated to giving all kids with spinal muscular atrophy not just better care, but better lives.

Regional SMA Highlights 

Services, programs and care teams differ at each location. Call for details.

Best hospital for Pediatric Neurology

We offer complete SMA care for kids at Nemours/Alfred I. duPont Hospital for Children (Wilmington, Del.).

  • the only muscular dystrophy program of its kind in Delaware, certified and approved by the Muscular Dystrophy Association (MDA)
  • Muscle Respiratory Care Clinic to help with breathing problems that can happen in kids with neuromuscular disorders like SMA
  • advanced devices developed by our researchers, like the Wilmington Robotic EXoskeleton (WREX), which helps kids with weak muscles move their arms
  • gait and motion analysis — precise, computer-aided camera tracking of body movements to help diagnose problems and figure out the best treatments
  • academic medical center, where our experts teach the next generation of specialists
  • Ronald McDonald House of Delaware , right across from our campus, for an affordable home away from home during long hospital stays

We offer complete SMA care for kids at Nemours Children’s Hospital (Orlando).

We offer complete SMA care for kids at Nemours Children’s Specialty Care, Jacksonville, working with Wolfson Children’s Hospital.

Patient Stories

Patient Stories


Matthew tells his pediatric neurology story.

Sometimes the best support and peace of mind comes from families who’ve been there. Meet some of the inspiring kids we’ve been honored to treat.

See Patient Stories »

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Research & Clinical Trials

At Nemours, we’re actively researching new approaches for childhood disease prevention, diagnosis and treatment.

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KidsHealth Library

Learn more about your child’s medical condition from the experts at Nemours’ KidsHealth.