Spinal Muscular Atrophy is a genetic disease that damages the nerves controlling the muscles of the body, resulting in weakness.  While it is considered a rare disease, it is the number one genetic killer of children under the age of 2.  The muscles closest to the trunk are more affected than those further away, and the legs are usually weaker than the arms.

The swallowing and breathing muscles can also be affected. Intelligence is typically normal, and people with SMA are often considered to be exceptionally bright and social.
There are four main types of SMA:

SMA Type I:  Symptoms usually appear by the age of 6 months, as evidenced by poor head/trunk control, feeding difficulties, and abnormal breathing patterns.  These children never learn to sit up, crawl or walk on their own, and are at high risk of developing life-threatening respiratory infections before the age of two.

SMA Type II:  Symptoms usually appear by the age of 18 months, as these children learn to sit up on their own, but never learn to walk.  They may or may not crawl.  They are at risk of developing respiratory illness, contractures, and scoliosis.  Their primary source of mobility is typically a power wheelchair, and they will likely need assistance with transfers.  They generally live a long and fulfilling life.

SMA  Type III:  These children will walk at least a short distance, so symptoms of weakness and decreased endurance may not be noticed until as late as 3 years of age.   They often lose the ability to walk at some point in their life.  They normally live a long and fulfilling life.

SMA Type IV:  Symptoms aren’t usually diagnosed until young to midlife adults.  People with Type IV SMA walk independently for at least a period of time, and live a long, high quality life.


An evaluation by a speech, occupational and/or physical therapist will likely be beneficial.  Speech will evaluate swallowing, feeding and communication.  Occupational therapy will evaluate your child’s ability to write, type, feed themselves, dress themselves, etc.  Physical therapy will assess your child’s strength, range of motion, and ability to roll/sit/crawl/walk.   All these therapists can evaluate breathing function.


While currently no cure exists for SMA, there is a lot we can do for treatment.  The goal of treatment is to improve quality of life and function. 
Non-drug therapies:
  • Physical Therapy
  • Occupational Therapy
  • Speech Therapy
  • Respiratory Therapy (Bi-PAP, cough assist)
  • Aquatic Therapy
  • Hypnotherapy
  • Adaptive Equipment (wheelchair, splints, etc)
  • Feeding tubes
  • VEPTR/Spinal Fusion
Oral Medications:
You will want to discuss options for medications with your physician.
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