Spinal muscular atrophy
Spinal muscular atrophy (SMA) is a genetic condition that makes the muscles weaker and causes problems with movement. It's a serious condition that gets worse over time, but there are treatments to help manage the symptoms.
Symptoms of SMA
The symptoms of SMA and when they first appear depend on the type of SMA you have.
Typical symptoms include:
- floppy or weak arms and legs
- movement problems – such as difficulty sitting up, crawling or walking
- twitching or shaking muscles (tremors)
- bone and joint problems – such as an unusually curved spine (scoliosis)
- swallowing problems
- difficulty breathing
SMA doesn't affect intelligence or cause learning disabilities.
Types of SMA
There are several types of SMA, which start at different ages. Some types cause more serious problems than others.
The main types are:
- type 1 – develops in babies less than six months old and is the most severe type
- type 2 – appears in babies who are 7-18 months old and is less severe than type 1
- type 3 – develops after 18 months of age and is the least severe type affecting children
- type 4 – affects adults and usually only causes mild problems
Babies with type 1 rarely survive beyond the first few years of life. Most children with type 2 survive into adulthood and can live long, fulfilling lives. Types 3 and 4 don't usually affect life expectancy.
Treatments for SMA
It's not currently possible to cure SMA. But research is ongoing to find possible new treatments.
Treatment and support is available to manage the symptoms and help people with SMA have the best possible quality of life.
Treatment may involve:
- exercises and equipment to help with movement and breathing
- feeding tubes and diet advice
- braces or surgery to treat problems with the spine or joints
A range of healthcare professionals may be involved in your care, including specialist doctors, physiotherapists, occupational therapists, and speech and language therapists.
Tests for SMA
The genetic problem that causes SMA is passed on to a child by their parents.
Speak to your GP if you're planning a pregnancy and:
- you've had a child with SMA before
- you have a history of the condition in your family
- your partner has a history of the condition in their family
Your GP may refer you to hospital, for specialist advice, to discuss the risk of the condition affecting a future pregnancy and any tests you can have.
If you're pregnant and there's a chance your baby could have SMA, tests can be carried out to check if they'll be born with the condition.
Tests can also be done after birth to diagnose SMA in children and adults.
In most cases, a child can only be born with SMA if both of their parents have a faulty gene that causes the condition.
The parents won't usually have SMA themselves, which is known as being a "carrier".
Some rarer types of SMA are inherited in a slightly different way, or may not be passed on at all.
More useful links
The information on this page has been adapted from original content from the NHS website.
For further information see terms and conditions.