Prevalence of obstructive sleep apnea in patients with mucopolysaccharidosis types I, II, and VI in a reference center

Purpose Mucopolysaccharidosis (MPS) encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans in organs and tissues. Respiratory disorders occur in all MPS types. In these patients, the prevalence of obstructive sleep apnea syndrome (OSAS), which may confer additional morbidity, remains overlooked, and the results of the few existing studies are controversial. The present study aimed to characterize the prevalence of OSAS in patients with MPS types I, II, and VI in a reference center. Methods Forty-five patients with MPS (I, n = 17; II, n = 16; and VI; n = 12) in the Centro de Referência em Erros Inatos do Metabolismo, who underwent full-night polysomnography, were enrolled in a retrospective study. Demographic data and clinical history were collected from medical records of the first medical consultation. Results The prevalence of OSAS in patients with MPS was 69.8 %. MPS type I patients seemed to be more susceptible to OSA-induced hypoxemia, as indicated by reduced mean SpO 2 levels during both NREM and rapid eye movement sleep as well as during SpO 2 nadir. Conclusions Patients with MPS displayed a high prevalence of OSAS, often with moderate to high severity. Together, our results reinforce the need for OSAS screening in all patients with MPS.