0777 Respiratory Sleep Phenotypes in Prader-Willi Syndrome: Does the Type of Mutation Matter?

Abstract Introduction Prader-Willi Syndrome (PWS) is a congenital disorder with three types of mutation: deletion (DEL), maternal uniparental disomy (UPD), and imprinting center defects (IMP). Sleep breathing disorders and sleep disruption may change the clinical evolution of these patients. The study aimed to evaluate the clinical characteristics of PWS patients according to genetic mutation, characterizing their sleep phenotypes and focusing on sleep respiratory measures. Methods From a cohort (January 2014 to July 2021) 55 patients of the same research university center with confirmed PWS genetic diagnosis consented. We applied questionnaires for sleep disorders, physical examination, nasolaryngoscopy, and overnight polysomnography Results Participants were aged between 2 and 22 years with genetic confirmation for PWS: 28 DEL, 21 UPD, and 6 IMP, and 24 (43.6%) were male participants patients with UPD and DEL mutations underwent polysomnography. They were divided into three quartiles (Q1, Q2, and Q3) for each respiratory parameter: the apnea-hypopnea index (AHI), the time of SpO2 (minutes) during sleep (SpO2min), and T< 90%. The AHI values of Q3-DEL (AHI: 15.2) were higher than Q3-DUM (AHI: 10.3). The SpO2min in the DEL group was 62%, while in the UPD group it was 76%. Patients in the DEL group had a higher prevalence in longer quartiles with T< 90%. Conclusion PWS patients showed specific respiratory sleep phenotypes according to genetic diagnosis. We found that PWS patients with DEL had worse polysomnographic respiratory patterns. Further studies are needed to recognize the clinical implications of the sleep respiratory findings in the clinical endophenotype of PWS. Support (if any)