In a case report, they described severe OSAin an adult patient, and emphasized that macroglossia and tonguepathology could be the underlying cause. Subsequently, Mellies and colleagues evaluated the prevalence of sleep disordered breathing in 27 subjects with juvenile or adult onset Pompe disease. Substantial disturbances in breathing during sleep were present in13 of the subjects, however, only 1 individual showed evidencefor OSA (Mellies et al., 2001). In another study, five adult Pompe patients underwent overnight polysomnography prior to initiation of mechanical ventilator support (Pellegrini et al., 2005). Theapneahypopnea index (AHI) ranged from 7 to 28 events per hour and the duration of significant desaturation events (