Newborn screening improves spinal muscular atrophy symptoms

Children with spinal muscular atrophy (SMA) will be more likely able to walk if they received newborn screening (NBS) and early treatment, according to a recent study published in The Lancet Child and Adolescent Health journal.

SMA, a rare neuromuscular condition, presents in childhood through weak muscles and issues with movement. These issues often lead to disability or death. SMA is a genetic condition with the main gene carried by about 1 in every 40 to 60 individuals, causing about 1 in every 10,000 infants to develop the disease.

Symptoms can appear in infants with SMA at different ages, with some infants being several months old before showing symptoms. This can lead to delays in diagnosis and treatment for improving symptoms. This treatment is often more effective if it begins before clinical symptoms develop.

NBS allows infants to be examined for conditions shortly after birth. These conditions are usually treatable, but not clearly present in newborns. NBS can lead to early diagnosis and treatment, improving symptoms in children.

The study compared the health of 15 infants diagnosed with SMA after NBS from August 1, 2018, to August 1, 2020, with the health of 18 infants diagnosed with SMA after a clinical referral within 2 years before the start of the pilot. Nine of the 15 children diagnosed after NBS did not show symptoms in the first week of life and were considered pre-symptomatic when treatment began.

Health professionals evaluated children’s ability to sit, crawl, stand, and walk 2 years postdiagnosis. One child diagnosed by NBS and 2 by symptom onset entered palliative care during the 2-year period and were not included in the analysis.

Of the 14 children diagnosed by NBS, 11 were able to walk on their own or with support 2 years postdiagnosis. In comparison, only 1 of the 16 children diagnosed before the NBS pilot began showed similar outcomes. 

While children given NBS screening were younger than those diagnosed after a clinical referral, these children often also showed improved scores on measures of movement ability and independence in everyday tasks. This indicates that the delays for diagnosis and treatment of SMA are reduced by NBS.

Reference

Newborn screening for spinal muscular atrophy leads to more children being able to walk at two years post diagnosis, new study suggests. The Lancet Child & Adolescent Health. January 17, 2023. Accessed January 17, 2023. https://www.thelancet.com/journals/lanchi/article/PIIS2352-4642(22)00342-X/fulltext