Spinal muscular atrophy (SMA) is a rare neuromuscular disorder that results in the loss of motor neurons and progressive muscle wasting. It is usually diagnosed in infancy or early childhood and if left untreated it is the most common genetic cause of infant death. It may also appear later in life and then have a milder course of the disease. The common feature is progressive weakness of voluntary muscles, with arm, leg and respiratory muscles being affected first. Associated problems may include poor head control, difficulties swallowing, scoliosis, and joint contractures.The age of onset and the severity of symptoms form the basis of the traditional classification of spinal muscular atrophy into a number of types.Spinal muscular atrophy is due to an abnormality (mutation) in the SMN1 gene which encodes SMN, a protein necessary for survival of motor neurons. Loss of these neurons in the spinal cord prevents signalling between the brain and skeletal muscles. Another gene, SMN2, is considered a disease modifying gene, since usually the more the SMN2 copies, the milder is the disease course. The diagnosis of SMA is based on symptoms and confirmed by genetic testing.Usually, the mutation in the SMN1 gene is inherited from both parents in an autosomal recessive manner, although in around 2% of cases it occurs during early development (de novo).
Stem cells
Whilst stem cells never form a part of any recognised therapy for SMA, a number of private companies, usually located in countries with lax regulatory oversight, take advantage of media hype and market stem cell injections as a "cure" for a vast range of disorders, including SMA. The medical consensus is that such procedures offer no clinical benefit whilst carrying significant risk, therefore people with SMA are advised against them. In 2013–2014, a small number of SMA1 children in Italy received court-mandated stem cell injections following the Stamina scam, but the treatment was reported having no effect

Registries
People with SMA in the European Union can participate in clinical research by entering their details into registries managed by TREAT-NMD. See also
Accomable
Motor neuron disease

References
Further reading
External links

Spinal muscular atrophy at Curlie
SMA at NINDS
SMArt Moves. Cure SMA. Retrieved 3 December 2021.