About SMA

SMA is caused by a mutation in the survival motor neuron gene 1 (SMN1). In a healthy person, this gene produces a protein that is critical to the function of the nerves that control our muscles. Without it, those nerve cells cannot properly function and eventually die, leading to debilitating and often fatal muscle weakness. 

SMA affects approximately 1 in 11,000 babies, and about 1 in every 50 Americans is a genetic carrier. SMA can affect any race or gender.

There are four primary types of SMA—I, II, III, and IV—based on age of onset and highest physical milestone achieved.

Individuals with SMA have difficulty performing the basic functions of life, like breathing and swallowing. However, SMA does not affect a person’s ability to think, learn, and build relationships with others.

There’s great reason for hope. Thanks to the dedication of our community and the ingenuity of our researchers, we now have the first-ever approved treatment that targets the underlying genetics of SMA. But our work is not done. We know what we need to do to develop and deliver effective therapies. And we’re on the verge of further breakthroughs that will continue to change the course of SMA for everyone affected—from infants to adults—and eventually lead to a cure.