Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a genetic, progressive, and often terminal rare disease that affects an individual’s ability to walk, eat, and, ultimately, breathe.1,2 Debilitating and often fatal, SMA affects approximately one in 10,000 live births and is a leading genetic cause of death among infants.3

SMA impacts individuals across a range of ages – from infants and children to teens and adults – with varying levels of severity.1 Newborns and infants are most likely to develop infantile-onset SMA, the most severe form of the disease, which can lead to paralysis and prevent infants from performing the basic functions of life, such as swallowing or holding up their heads.3 Later-onset SMA is most common among teens and adults, who may experience significant muscle weakness and disability, and lose the ability to stand or walk independently.1

SMA can occur when a mutated SMN1 gene is passed on to a child by both parents.4 The SMN1 gene is responsible for the body’s production of SMN protein, which is vital to the function of muscles that enable movement, speech, breathing and swallowing.4 Without sufficient production of SMN protein, the nerves deteriorate and muscle wasting occurs.4

One in forty to sixty people may unknowingly carry a mutation of the SMN1 gene.4 If two carriers of the mutated gene have a child there is a one-in-four chance that the child will have SMA.

Individuals with two copies of the SMN2 gene, the gene responsible for making the survival motor neuron (SMN) protein, are most likely to develop infantile-onset SMA (also known as Type 1), while those with three or four copies are most likely to develop later-onset SMA (Types 2 and 3).4

Learn more about SMA.


Therapy for SMA

Until recently there were no treatment options for people with SMA, but in the past couple of years, the treatment landscape has changed with Biogen making available the first ever treatment for this devastating disease.5

Biogen is dedicated to enhancing the lives of those with SMA and their caregivers through ongoing research, removing non-clinical access barriers and providing support programs for eligible patients. The company looks forward to continuing to advance its cutting-edge research, science and technological capabilities to support and enhance the lives of individuals with SMA, their families and the SMA community.

Learn more about SMA here.



1 Lin C-W et al. (2015). Delay in Diagnosis of Spinal Muscular Atrophy: A Systematic Literature Review. Pediatric Neurology, 53, 293e300.
2 National Institute of Health. SMN1 gene. [Online] Available at: https://ghr.nlm.nih.gov/gene/SMN1#conditions, last accessed 21 August 2018.
3 D’Amico, Mercuri, Tiziano & Bertini. (2011). Spinal muscular atrophy. Orphanet Journal of rare Diseases, 6:71.
4 Farrar MA, Kiernan MC. The Genetics of Spinal Muscular Atrophy: Progress and Challenges. Neurotherapeutics; 2015; 12:290–302.
5 Biogen. SPINRAZA Product Information. November 2017.