Sleep-disordered breathing in Prader-Willi syndrome: Two illustrative examples

Prader-Willi syndrome (PWS) is a genetic disorder characterized by hypothalamic dysfunction, resulting in a combination of neurodevelopmental, metabolic, and behavioral abnormalities. Sleep disorders are frequent and often severe and constitute a major component of the clinical phenotype. However, sleep disorders affecting PWS patients remain under-recognized and undertreated.

We report two pediatric cases of PWS illustrating divergently evolving pattern of sleep-disordered breathing.The first patient, L.K., aged 10, presented with severe sleep apnea-hypopnea syndrome including a prominent central component (AHI: 31.8/h; central apneas: 15.2/h). Auto-SV ventilation followed by fixed PAP therapy led to a significant reduction in indices (final AHI: 5/h), improvement in deep sleep (N3: 50.2 %), and a decrease in micro-arousals, with observed behavioral benefits reported by caregivers.The second patient, R.K., followed since the age of 10, progressed from moderate OSA (AHI: 5.6/h) to a phenotype dominated by central events (AHI: 27.8/h including 25.4/h central). A personalized fixed-pressure PAP titration resulted in long-term control of respiratory events, maintained over six years, with adherence exceeding 5 h/night and a residual AHI of 1.3/h.

These cases highlight the complex pathophysiology of sleep disorders in PWS, involving peripheral hypotonia, central hypothalamic dysregulation, and ventilatory control instability. They also underscore the central role of polysomnography in screening and tailoring ventilatory support treatment.

Tailored nocturnal ventilation improves not only breathing but also sleep quality and behavioral functioning, as suggested by previous clinical observations linking ventilatory correction to behavioral improvements in PWS.