Symptoms & Effects of 5q Spinal Muscular Atrophy
Symptoms & Effects of 5q Spinal Muscular Atrophy
The ‘Natural History’ of SMA
Before drug treatments (also sometimes known as ‘disease-modifying’ treatments) started to be developed and tested for 5q SMA, clinicians and researchers gathered information about what impact someone might expect the condition to have on them.
This is called the ‘natural history’ of the condition.
This led to 5q SMA being divided into four main ‘Types’ of SMA: Types 1, 2, 3, and 4. Sometimes a baby is affected before birth; this is called Type 0.
These ‘Types’ of SMA were based on the age that symptoms began, and what physical milestones (e.g. sitting, standing, walking) could be achieved. It was agreed that there could be variation both within and between Types.
This classification system is still used for adults, teenagers and children living with SMA in the UK even though for many, care and / or treatment is changing the outcome of their SMA.
What would the ‘natural history’ of my child’s / my SMA look like?
- Children, young people and adults will have started to show symptoms that will have led to tests confirming they have SMA.
- A baby may have been diagnosed with SMA because of their symptoms or because they have been part of the Oxford / Thames Valley-based SMA newborn screening study and been diagnosed with SMA.
To try to answer this, a specialist clinician will examine any child or adult with suspected SMA.
They will also consider:
- the age of the child or adult when the SMN1 gene deletion test confirmed SMA
- any symptoms of SMA and when these first started
- how many SMN2 gene copies the test result showed
- any family history of SMA
And will refer to this summary:
Table adapted from Tillmann et al.
