SMA Newborn Screening in California Results in Early Disease Detection

Within the first 18 months of universal spinal muscular atrophy (SMA) newborn screening in California, the disorder was identified in 34 infants, the majority of whom received treatment while still asymptomatic. Public health officials described program outcomes in an article in the Journal of Neuromuscular Diseases.

The state implemented universal SMA screening for newborns in June 2020, explained a team from the California Department of Public Health in Richmond.

“Dried blood spots are screened for SMA using multiplex real time polymerase chain reaction (RT-PCR) to detect deletions of exon 7 in the survival of motor neuron 1 (SMN1) gene,” wrote corresponding author Jamie Matteson, MPH, and coauthors. “Short-term follow-up data is collected from clinical staff via an online data collection tool.”

Some 628,791 newborns underwent testing for SMA over the first 18 months of the program. According to the study, 34 of them screened positive and were confirmed to have SMA.

The median time to referral was 8 days of life. Diagnosis occurred at a median 12 days of life, and treatment was initiated at a median 33 days of life.

Sixty-two percent of the babies diagnosed with SMA received treatment before symptoms emerged, the study found.

“SMA newborn screening is a highly sensitive and specific test, which identifies infants with SMA early when treatment is most effective,” researchers wrote. “Even with newborn screening’s success in facilitating early intervention, there is still work to be done to expedite treatment, especially for infants with the most severe form of the disease.”

Reference:
Matteson J, Wu CH, Mathur D, et al. California's experience with SMA newborn screening: a successful path to early intervention. J Neuromuscul Dis. 2022;9(6):777-785. doi:10.3233/JND-221561