What is Spinal Muscular Atrophy (SMA)?
by Jens Kleine - Physiotherapist and Product Specialist on 06.04.2018
SMA is a serious condition that can worsen over time.
Spinal muscular atrophy (SMA) is a genetic disease, causing muscle weakness and problems with movement.
When you have SMA, there’s a breakdown in the nerve cells in the brain and spinal cord. The condition primarily affects muscles, which can’t receive signals from these cells.
SMA isn’t curable, but there are treatments and support available that can make it easier to manage symptoms.
How does it occur?
A child with SMA has two copies of a broken gene. Both parents pass on a broken gene each, and this causes difficulties producing a specific protein. Without this protein, cells controlling muscles die.
This weakens and shrinks muscles, and can cause troubles with head movements, sitting and walking.
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Symptoms will depend on the type of SMA inherited. The main types are:
- Type 1: The most severe and common type, usually diagnosed during an infant’s first six months. Babies with type 1 can experience muscle weaknesses and trouble breathing.
- Type 2: Diagnosed after six months and before two years of age. Children with type 2 are often able to sit on their own but may need assistance and/or assistive devices to move.
- Type 3: Usually diagnosed after 18 months but before 3 years of age. Children with type 3 may be able to walk but can experience limited mobility as they grow. In fact, type 3 can be diagnosed as late as the teenage years.
- Type 4: This type is very rare and usually occurs in adulthood. Symptoms can show at the age of 18 at the earliest, but usually after the age of 35.
According to NHS Choices, symptoms include (but are not limited to):
- floppy or weak arms and legs
- movement problems
- twitching or shaking muscles (tremors)
- bone and joint problems – such as an unusually curved spine (scoliosis)
- swallowing problems
- breathing difficulties
At this moment, curing SMA is not possible, but treatments that can help reduce symptoms are:
- exercises and assistive devices
- feeding tubes
- diet advice
- braces or surgery to help with spine or joint problems
As symptoms and severity of SMA vary, treatment should be adjusted to each individual’s needs. People with SMA should seek advice from health professionals, who can outline support and treatments. Recent advances in medicine suggests Spinraza, a newly developed medicine that can help people with SMA. Spinraza is FDA approved, but is yet to be accepted in some countries due to a disagreement in pricing. Norway and Denmark are among the nations who are looking to negotiate with Biogen, the pharmaceutical behind Spinraza.