Spinal Muscular Atrophy (SMA)

Luke Newton


Spinal Muscular Atrophy is a disorder that affects the signal nerves which in turn causes the muscles in the body to become very weak almost to the point where they no longer function at all. Someone with this disorder would need assistance crawling, sitting, or walking.

How Could Our Baby Have This?


This disorder is inherited in an autosomal recessive pattern. Recessive traits must have two copies of a gene to be expressed. For example, both of a child's parents could be normal and have no symptoms and still be a carrier and pass the gene to their child. Mutations on chromosome 5 and in the gene: SMN1. However, the number of SMN2 genes modifies the severity. The disorder is caused by missense mutations by way of insertion and deletions.

What Can Be Expected

Physical Changes

The muscles of the effected person will shrink and become weak. In some cases, the muscles that facilitate breathing and swallowing fail to function properly, this causes additional problems or even death. Since the severity of Spinal Muscular Atrophy varies so greatly, some patients dies young while others live well into adulthood.


There are currently no effective medications for SMA. There has been a little success in mice with gene therapy.

What types of tests are done?

An in-office physical examination and family history, with some simple tests to distinguish spinal muscular atrophy from similar conditions.

At what age is diagnosis likely to be done?

They begin directly after birth be can continue for a couple years

Is genetic counseling an option?

Yes, you can look at your family history and determine a possibility of a child having SMA.

Who Is Affected

Spinal muscular atrophy affects 1 in 6,000 to 1 in 10,000 people.
SMA does not affect certain types or groups of people.

Is it Fatal?

Type 1and type 2 are fatal while those with type 3,4, and 5 live longer but not a normal lifespan


"Spinal Muscular Atrophy." Genetics Home Reference. Web. 16 Mar. 2015. <http://ghr.nlm.nih.gov/condition/spinal-muscular-atrophy>.
"Spinal Muscular Atrophy Treatment & Management." Spinal Muscular Atrophy Treatment & Management. N.p., n.d. Web. 21 Mar. 2015.<http://emedicine.medscape.com/article/1181436-treatment>

"Diagnosis Spinal Muscular Atrophy." Muscular Dystrophy Association. N.p., n.d. Web. 21 Mar. 2015. <http://mda.org/disease/spinal-muscular-atrophy/diagnosis>.