Background:
Early identification of spinal muscular atrophy (SMA) through newborn screening (NBS) enables the timely initiation of disease-modifying therapies (DMTs). However, data on sleep-disordered breathing (SDB) in this early-treated population remain limited, leaving uncertainty regarding the optimal timing of respiratory surveillance.
Objective:
To evaluate polysomnography (PSG) findings in children with SMA type 1 diagnosed via NBS.
Methods:
We retrospectively reviewed patients with SMA1 diagnosed by NBS who underwent PSG between October 2023 and October 2025. The studies were analysed according to the standards of the American Academy of Sleep Medicine. Demographic and PSG data were summarized descriptively. All patients were identified through a single national newborn screening program but managed at different hospitals, reflecting real-world variability in respiratory surveillance and ventilation practices.
Results:
Twenty-three children were included (14 female, 61%). Median age at PSG was 17 months (range 4–46). All had received nusinersen, whereas 12 (52%) also received onasemnogene abeparvovec before PSG. Eleven (48%) had established home nocturnal or illness-related ventilation initiated on clinical grounds before PSG. Seventeen (74%) demonstrated elevated apnea–hypopnea index (AHI) (median 3.25, IQR 1.75–6.15): 9 mild (1–4), 7 moderate (5–10), 1 severe (>10). Initiation or re-initiation of nocturnal ventilation was recommended in 6 (26%) patients. Three of these already possessed BiPAP devices, prescribed for symptomatic use but not in regular use before PSG. Ten patients (8 mild, 2 moderate OSA) were advised to repeat PSG in 6–12 months.
Conclusions:
Despite early diagnosis and DMT, three-quarters of NBS-identified SMA1 patients showed abnormal PSG findings, and one-quarter required new or renewed ventilatory support. Objective sleep studies revealed previously unrecognized SDB even among children with existing BiPAP access, underscoring the importance of early and routine PSG surveillance. These findings highlight the need for proactive, standardized respiratory monitoring protocols within NBS programs.