SMA is defined as a neuromuscular disease of the central nervous system (CNS) that results in the deterioration of motor function and strength over time, although the rate and severity vary. Watch to learn more about the causes and symptoms of SMA.3-5
Watch the video to learn about the clinical manifestations and cause of SMA.
Two nearly identical genes produce survival motor neuron (SMN) protein7
People with SMA have a homozygous deletion of their SMN1 gene, and rely on the SMN2 gene to produce functional SMN protein. However, SMN2 can only produce about 10% of the protein the motor neurons need to power muscles, resulting in the progressive loss of strength and motor function that all with SMA experience.
Because the rate of motor function loss is different for every patient, there is no way to predict when motor function loss will occur or how severe it will be.
Despite apparent plateaus, untreated adults with later-onset SMA will continue to lose muscle strength or function over time.