- Key Facts about Spinal Muscular Atrophy
- SMA Information for Families. This information sheet briefly explains what Spinal Muscular Atrophy (SMA) is and what can cause it.
The four main types of SMA vary greatly in severity and the effects vary between individuals:
- SMA Type 1. Symptoms appear within the first few months of life, sometimes before birth. Children are never able to sit unaided and rarely survive their second birthday.
- SMA Type 2. Symptoms usually appear between 7-18 months of age. Children are never able to stand unaided. Although the condition may shorten life-expectancy, improvements in care standards mean that the majority of people can live long and fulfilling lives.
- SMA Type 3. Symptoms appear after 18 months of age. Children are able to stand and walk, but will become less able to walk over time. Life-expectancy is normal and most people can live long independent lives.
- SMA Type 4 (also known as Adult Onset SMA). Symptoms appear in adulthood. It is not a life-threatening condition.
Our thanks to Spinal Muscular Atrophy Support UK (SMA Support UK), a certified member of The Information Standard, who have produced these factsheets. Muscular Dystrophy UK works closely with SMA Support UK and endorses the information provided in the above factsheets.