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  • Treatment is available for babies with 3 or less copies of the SMN2 gene.  Babies with 3 or less copies of the SMN2 gene are expected to have SMA types 1, 2 or 3.
  • Babies with 4 or more copies of the SMN2 gene will be checked regularly for symptoms of SMA.  Babies with SMN2 copy numbers of 4 or more are expected to have SMA types 3 or 4, but some babies may develop type 2.  If symptoms develop your baby’s specialist will discuss treatment options.
  • Treatment needs to begin as early as possible for infants with 3 or less copies of the SMN2 gene.  This is why newborn screening for SMA is being offered.  Without treatment the more severe, early onset forms of SMA (in particular SMA type 1) will lead to death in the first year or two of life.
  • A team, including a pediatric neurologist, cares for babies with SMA.
  • Regular follow-up tests are used to monitor and adjust treatments.
  • Babies with SMA have their health and development checked regularly.


  • In Ontario, Nusinersen is approved for treatment of patients with SMA who have 3 or less copies of the SMN2 gene.
    • Treatment is provided at a medical facility or hospital by a physician.
    • Treatment with Nusinersen is given through a lumbar puncture (spinal tap).
    • Six treatments are required in the first year of life and then 3 times per year for life; Treatment is lifelong.
    • Nusinersen can stop the progression of SMA if started early. 


  • Gene therapy (Zolgensma) is being developed but is not yet approved for use in Canada. It may be available on a compassionate basis through Global Access Program however this cannot be guaranteed.


The pediatric neurologist will discuss all of your management and treatment options with you.