Spinal Muscular Atrophy (SMA)

Northwestern Medicine Neuromuscular Program at Northwestern Memorial Hospital has extensive experience diagnosing and treating spinal muscular atrophy (SMA). Northwestern Memorial Hospital is currently the only provider of Nusinersen in Illinois, treating a growing number of patients who have different types of SMAs, including Types III and IV.

Nusinersen is the only FDA-approved treatment for spinal muscular atrophy, and has been shown to halt the progression of spinal muscular atrophy. It may also help people regain some of the motor function they have lost.

What is Spinal Muscular Atrophy (SMA)?

Spinal muscular atrophy (SMA) is a disease that affects the central nervous system. It damages the nerve cells that control how muscles work. As a result, muscles slowly weaken and waste away.

SMA is a genetic disease, and a person can only get it only if he or she inherits the gene for it from both parents.

There are several different types of SMA. Each begins at a different age for patients:

  • Type 1: (Werdnig-Hoffmann SMA): Also called infantile-onset SMA. A child with this type often has symptoms just after birth. An infant may have trouble moving, swallowing, and feeding. The infant may not be able to hold up his or her head. A child with this severe form of SMA usually dies within 2 to 6 years. Children with type 1 often die from breathing problems.
  • Type 2: (Juvenile or chronic SMA): A child with this type is often diagnosed at age 6 to 18 months. The main symptom is muscle weakness all over the body. This causes trouble walking and standing. Children with type 2 may need help moving around. They may need a walker or wheelchair. They often live into adulthood. But they are more prone to respiratory infections.
  • Type 3: (sometimes called Kugelberg-Welander disease): This is the mildest form. It can affect children from 18 months old up to their teen years. The most common symptoms include clumsiness, trouble walking and climbing steps, fine tremor, and muscle weakness. Children with type 3 often have trouble getting up from a sitting position.