Testing & Diagnosis for Spinal Muscular Atrophy (SMA) in Children

LIke ThisLIke ThisLIke ThisLIke ThisLIke This

Contact the Spinal Muscular Atrophy Program

The first step in treating your child is forming an accurate and complete diagnosis. To diagnose your child's SMA, your specialist at Boston Children's Hospital uses a combination of medical history, physical examination and laboratory tests.

How is spinal muscular atrophy diagnosed?

Spinal muscular atrophy is sometimes difficult to diagnose, as symptoms can resemble other conditions or medical problems. Doctors usually diagnose it after a child has suddenly or gradually shown muscle weakness and decreased muscle tone.

The work-up for a child with muscle weakness, when SMA is suspected, includes:

  • a detailed physical exam
  • gathering of past medical history
  • gathering of family history information
  • diagnostic testing
    • genetic blood tests
    • an electromyography (EMG) test that measures the electrical activity of a muscle or a group of muscles
    • in exceptionally rare cases, a child may need a muscle biopsy
    • creatine kinase (CPK) test (to distinguish from other types of muscle diseases, if necessary)
    • Type III SMA can often be misdiagnosed as muscular dystrophy.
    • SMA will result in normal or slightly elevated CPK enzyme levels while muscular dystrophy (MD) results in much higher CPK levels.
  • EMG lab

    Experience counts when it comes to conducting an electromyography (EMG) test correctly and compassionately. For more than 30 years, the EMG lab has been reading EMG tests and making children feel safe and comfortable during this procedure. This test is used sometimes when SMA is suspected.

    Future of child neurology

    Children’s Hospital Boston not only provides the best child neurology care, but also trains the best doctors to continue exceptional care for your children and your children’s children. Learn more about the child neurology residency training program.

We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

Boston Children's Hospital 300 Longwood Avenue, Boston, MA 02115 617-355-6000 | 800-355-7944