Report Highlights Sleep Findings in Infants With SMA Treated With Onasemnogene-Abeparvovec

Polysomnography of infants with spinal muscular atrophy (SMA) treated with onasemnogene-abeparvovec revealed an apnea-hypopnea index (AHI) range between 3 and 24 events an hour, according to study findings published in Sleep Medicine.

“Sleep-disordered breathing is common in patients with neuromuscular diseases, including spinal muscular atrophy,” wrote corresponding study author Carmen Leon-Astudillo, MD, of the University of Florida College of Medicine Department of Pediatrics in Gainesville, and coauthors. “While polysomnography findings have been described in natural history studies of patients with SMA, reports regarding polysomnography in treated children are limited to nusinersen.”

To broaden the offerings, researchers described the sleep characteristics of a cohort of eight infants with SMA followed at the University of Florida Health Center for Pediatric Neuromuscular and Rare Diseases.

The children, half of whom were female, were between the ages of 5 and 250 days at SMA diagnosis. Five infants had 2 survival motor neuron 2 (SMN2) copies, two had 3 SMN2 copies, and one had 4 SMN2 copies.

All of the infants underwent a diagnostic or split-night polysomnography after SMA treatment with onasemnogene-abeparvovec. In addition, one patient received nusinersen, and one received risdiplam. Age at time of treatment ranged between 20 and 257 days; the median was 46.5 days.

According to the study, AHI varied from 3.6 to 24.1 events per hour and was higher during rapid eye movement (REM) sleep than non-REM sleep. At the time of polysomnography, the median score on the Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) was 55, with a range between 33 and 64.

Researchers found no associations among age at treatment, CHOP INTEND score, and AHI.

“Sleep-disordered breathing is common in treated children with SMA,” they concluded, “regardless of age at diagnosis, treatment, and neuromotor scores.”

Reference:
Leon-Astudillo C, Wagner M, Salabarria SM, et al. Polysomnography findings in children with spinal muscular atrophy after onasemnogene-abeparvovec. Sleep Med. Published online November 10, 2022. doi:10.1016/j.sleep.2022.11.006