Giles Lomax, chief executive of charity SMA UK, said: “Without early diagnosis and treatment, babies with the most severe forms of SMA can experience rapid and irreversible muscle weakness, leading to serious disability and, in some cases, life-threatening complications.
“Today, we have effective treatments for SMA. But timing is everything. The evidence is clear: babies who are diagnosed and treated before symptoms appear have significantly better health outcomes.
“Many can meet developmental milestones that would not have been possible without early intervention. Once symptoms begin, damage to motor neurons cannot be undone.”
A Welsh government spokesperson said: “We follow advice from the UK National Screening Committee, which does not currently recommend routine newborn screening to detect SMA.
“The in-service evaluation in Scotland will help inform a recommendation from the UK NSC as to whether screening for SMA should be included as part of the newborn blood spot screening programmes across the UK.”
According to SMA UK, an estimated 47 babies were born with the condition in the UK in 2024, although about one in 40 people carry the altered gene that can cause the disease.