Studying how muscles develop in children diagnosed with SMA at birth

In the last 10 years, new treatments for spinal muscular atrophy (SMA) have become available. These treatments can help slow down the speed at which muscles get weaker. The earlier someone gets treatment, the better it works. That’s why many countries now test babies for SMA at birth.

Some babies who get treated early grow strong muscles and move well. But others still have some muscle problems that affect how they move. Scientists think this might depend on how severe the condition is and when treatment starts.

To help children who still have muscle problems after their first treatment, scientists are working on extra treatments. However, they are not yet sure of the best time these new treatments should be given or the best way to test how well they work as babies grow. To find out, they need to learn more about how muscles grow and change over time.

For people with milder forms of SMA, treatment isn’t always given from birth. Scientists also want to understand their muscle development better so they can decide when treatment should begin.

This project aims to test tools which can show how SMA affects movement over time, starting from as early as four months old. This will help scientists study muscle development and decide the best time to start treatment for children with different levels of severity.

The tools include:

• A soft jumpsuit worn during play at home by babies who aren’t walking yet. This tracks how they move and helps create a score called the Baba Infant Motor Score (BIMS).
• Ankle sensors called Syde, worn by children who can walk. These measure how they walk and help calculate a score called SV95C (Stride Velocity 96th centile).

These scores help scientists understand how well a child is moving and growing. They can also be useful in checking if a treatment is working.

This research is following a large group of babies diagnosed with SMA at birth. By testing new tools that track movement from an early age, researchers hope to find better ways to measure how SMA affects children as they grow. This will help them learn:

• When treatment works best.
• When to give extra treatments to children who still have muscle problems despite treatment at birth.
• When to start treatment in children with milder SMA who may not be treated at birth.

These tools could also be used in clinical trials to show how well treatments work. The findings might help doctors decide the best time to start or add treatment. In the future, this research could help all children with SMA get the right treatment at the right time.