Early treatment of infants with spinal muscular atrophy (SMA) improves outcomes. Newborn screening allows for early treatment of infants with SMA, even before signs of the disease are evident. In spite of early identification and treatment, newborn screen and prenatally-identified infants with SMA may still suffer effects of their disease. Approximately half of infants have significant gross motor developmental delays, while others meet developmental milestones on time. There is no current objective method to identify early-treated infants with SMA at risk for gross motor delays who might benefit from modifications to current treatment practices.
This multicenter project will report real world data on outcomes of early-treated infants with SMA. It will investigate if baseline pre-treatment Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) scores differ in infants with SMA with two copies SMN2, predicted to have more severe SMA type I, versus those with >2 copies of SMN2, and if baseline CHOP INTEND score predicts motor and functional development.
Retrospective chart review of all newborn screen identified or prenatally diagnosed children with SMA who were treated with nusinersen or onasemnogene abeparvovec at <=6 weeks of age between January 2019 and December 2022 at participating centers will be performed. Data on medical history, genetic test results, SMA treatment, longitudinal CHOP INTEND scores, growth parameters, bulbar and respiratory function, treatment-related adverse events, and age of gross motor milestone acquisition will be collected and analyzed. Results: If available, preliminary results on outcomes of early-treated infants with SMA will be reported. Conclusions: This study will contribute to the limited literature on real world outcomes of early treated infants with SMA, including if baseline pre-treatment CHOP INTEND score can predict gross motor delays in this population.