Spinal Muscular Atrophy


August is Spinal Muscular Atrophy (SMA) Awareness month. SMA is a group of genetic disorders that are characterized by a loss of certain protein that is necessary for the survival of some motor neurons in the spinal cord. The loss of these neurons leads to progressive muscle weakness and muscle atrophy, starting starting with the muscles in the lungs, neck, back, and legs.

Sadly, the symptoms for SMA usually begin in infancy. That’s why the 4 major classifications of the disorder describe not just its severity but also the highest attained motor development milestone. Type 1 manifests in the first months of life, usually quite suddenly with “floppy baby syndrome.” With respiratory support, babies who are diagnosed at this age have a 10% chance of living to adolescence and adulthood but most succumb to respiratory failure before the age of 2. The most severe cases (sometimes referred to as “Type 0”) are diagnosed in babies that are so weak at birth, they can only survive a handful of weeks.

The onset of symptoms for Type 2 is between 6-18 months. The babies affected by this intermediate form are never able to walk but might have been able to maintain a sitting position, at least at one point in their life. The outcome of Type 2 varies widely, depending on the individual and the therapy they receive. While the respiratory system remains a major concern, most of the children affected by Type 2 live well into adulthood, with their life expectancy only somewhat reduced from an average healthy person.

Type 3 has a normal, or near normal, life expectancy. Children affected by Type 3 are diagnosed sometime after 18 months of age and have usually achieved unassisted standing and walking at some point. The patient might only struggle with running, navigating stairs, or standing from a sitting position. They might also end up in a wheelchair later in life. The progression of SMA depends on the overall health of the individual and also on the therapies available to them.

Type 4 is also called “adult-onset SMA” because it usually begins to present symptoms when the patient is in their 30s. In this type, the muscles in the extremities gradually become weak and atrophy, often necessitating a wheelchair for mobility. Other complications - notably, respiratory problems - are not typical to Type 4. Perhaps because of the late onset, the life expectancy of a person with Type 4 is the same as the average person’s.

Currently, there is no cure for SMA, there are only treatments for the symptoms. Therapies include medication, physical therapy, nutrition (because of difficulty sucking or swallowing), and oxygen.

It’s important to note that while physically challenged by this disorder, the intelligence of a child with SMA is not affected. If your child is diagnosed with SMA, they can still lead a happy life full of friends and fulfillment.  In fact, Wikipedia reports that “their cognitive development can be slightly faster, and certain aspects of their intelligence are above average.” They also go on to mention that “SMA-affected people report a high degree of satisfaction from life.” Alyssa Silva is a wonderful example of resiliency and capability despite SMA. She is one of the rare examples of an infant with Type 1 who is thriving in adulthood. Read about life from her point of view on her blog; she’s funny, uplifting, and a bit of a workaholic.

Spinal Muscle Atrophy is not an easy disorder; in fact, it can be unbelievingly devastating. There is hope, however. As more people become aware of SMA and raise funds, researchers will be able to investigate better treatments and hopefully, a cure. For more information about SMA and how you can help, visit curesma.org

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