A study published in September 2022 in the Journal of Neuromuscular Diseases indicates that children with a neurological condition called spinal muscular atrophy (SMA) will benefit from early treatment instead of being kept waiting for the symptoms to manifest.
According to the researchers, early treatment can prevent irreversible muscle damage in affected children and improve the quality of their life.
Spinal muscular atrophy is a genetic condition that causes muscle weakness. It is generally diagnosed in early infancy. It occurs due to changes in a protein number called SMN (survival of motor neurons).
The severity of SMA depends on the subtle changes in a gene called SMN1 and the number of copies of its identical gene, SMN2. SMN1 and 2 together determine how a child can sit up, crawl, walk and control head movements.
Earlier it was understood that the presence of many SMN2 genes would counterbalance the effects of the defective SMN1 gene. And that the symptoms would manifest much later in childhood or adulthood, and the course of this condition would be mild.
However, contrary to this, the present study shows that a surprisingly large number of children with more than two copies of the SMN2 gene started showing the symptoms of SMA between the ages of 1.5 and 4 years.
SMA is usually treated with a combination of medicines and physical therapy. Although these treatments are expensive, the researchers believe it is better for the parents to bear the initial cost rather than wait for the symptoms to occur in their wards and then initiate the treatment.
They argue that the benefit of an early intervention could outweigh the economic impact of the treatment as it improves the quality of life of the children.
Guidelines changed in 2020
According to Cure SMA guidelines, until 2018, parents of children with SMA could initiate the treatment when weakness or reduced muscle action was seen. However, in 2020 these guidelines were revised, asking the parents to start early treatment for their children before the onset of symptoms.
The present study’s researchers wanted to verify the premise of the efficacy of an early treatment. Their findings concurred with the revised guidelines.
“The ‘wait and watch’ strategy might entail the risk of irreversible deformity for these children,” said Dr Katharina Vill, lead investigator of the study from the Department of Paediatric Neurology and Developmental Medicine, Munich, Germany, in a statement.
The researchers concluded their findings after screening 18 children with SMA between 2018 and 2021. Among them, 15 children were monitored for a long-term follow-up. Further, parents of eight of these children opted for early treatment for the children, while seven preferred to wait and watch.
The researchers observed that the group of children that was given early treatment had no symptoms of SMA to date. Whereas the seven children whose parents decided to wait were affected by muscular weakness, decreased endurance and nerve damage between the age of 1.5 and 4 years.
Although the symptoms were observed in only a few children, the researchers noticed that most of them showed symptoms within the first four years of life, with at least one irreversible symptom. “The proportion was much higher than expected,” explained Dr Vill in the statement.
From these observations, the researchers emphasise that early intervention in SMA cases can prevent permanent damage to nerve cells and muscles.
“We recommend encouraging parents to start a treatment regimen early in childhood. If the parents decide to wait, follow-up should be performed with extreme care,” said Dr Vill.
