Pop star Jesy Nelson has campaigned for screening to be rolled out after her twins were diagnosed with spinal muscular atrophy (SMA). Hundreds of children living with SMA are set to benefit from two life-changing treatments, which have now received official approval for routine use across the NHS.
What is SMA?
The NHS defines SMA as a rare genetic condition that can cause muscle weakness. Dr Charlotte Roy, life sciences policy and influencing manager at Muscular Dystrophy UK, explains: "SMA is a genetic condition that affects the motor neurons which send electrical signals from the brain to the muscles to tell them to move. As part of SMA, the motor neurons start to get damaged and break down, which means the message from the brain through to the muscles can't happen. As a result, the muscles will start to get weak and progressively waste away."
This happens because in most cases, SMA is caused by a change in the SMN1 gene located on chromosome 5 (5q). There are several different types of SMA. "SMA Type 1 is the most common and severe type, and the symptoms normally appear within the first six months," says Roy.
Five Key Early Signs of SMA in Babies
1) Profound muscle weakness
"When the motor neurons break down, the signal from the brain to the muscle can't get through. And if the signal doesn't get through to the muscles, the muscles don't move," explains Roy. "This leads to low muscle tone and floppiness in babies with SMA because their muscles aren't as strong as they should be as they start to waste away."
2) Difficulties with feeding and breathing
"Motor neurons control the signals for all muscles within the body, including the muscles that you need to use to breathe and swallow, so babies with SMA often experience difficulties breathing and swallowing," says Roy. This can become more obvious when they start moving onto eating more solid foods. "If they struggle swallowing food this can potentially lead to choking," she adds.
3) Unable to sit up alone
"One missed milestone to look out for is being able to sit up unsupported," says Roy. "Babies with SMA are often not able to sit up unsupported because they've got weak core muscles."
4) Poor head control
"Similarly, check to see if they are unable to raise their head, because SMA can lead to weakness in the neck muscles," says Roy.
5) Recurring chest infections
According to Muscular Dystrophy UK, babies and children with SMA type 1 are at higher risk of respiratory issues and chest infections. "Babies with SMA often get more chest infections, so that's another sign to look out for," says Roy.
When to Seek Advice
"If you notice anything that you think isn't quite right, I would recommend going to talk to your GP about it," advises Roy. "It most likely won't be SMA, but it's important to get any concerns checked out just in case, because with SMA early diagnosis is key. The GP will refer anything on to a neuromuscular specialist who can start the diagnosis process. Diagnosis usually involves genetic testing, because it's a genetic condition."
Why is Early Diagnosis So Important?
"Once your motor neurons have died, you can't bring them back. Therefore, we want to protect those motor neurons as much as possible," says Roy. "Early diagnosis means earlier treatment and better outcomes for the babies."
Without medical intervention, the most severe form of SMA (Type 1) can progress rapidly, with Muscular Dystrophy UK estimating a life expectancy of less than two years. Yet, NHS England has confirmed these therapies have already enabled 73 children with the condition to survive to age five or older. Public awareness of SMA increased significantly earlier this year when singer and former Little Mix member Jesy Nelson began speaking about the condition following the diagnosis of her twins, Ocean Jade and Story Monroe.
