Obstructive sleep apnea (OSA) is a common condition of Down syndrome patients. In pediatric practice, there is no way to determine the children with an increased risk. The aim of the study is to determine the reliability of four questionnaires used in pediatric patients in screening of OSA in Down syndrome children.

Prospective study where patients are evaluated on airway diseases and aeroallergens sensitization with 2 parental surveys (PSQ-SRBD and CSHQ), otolaryngologic problems by completing by the ENT surgeon 2 others surveys (CAS-15 and SCR), and sleep disease with an overnight polysomnography (PSG), in University Hospital in Nice.

Introduction: Children with Down syndrome (DS) commonly have obstructive sleep apnea (OSA) though undervalued by parents and physicians. Several sleep questionnaires are used in paediatric patients to detect high risk children who have OSA, but not really appropriate for DS patients. The aim of the study is to determine the reliability of four questionnaires used in paediatric patients (PSQ-SRBD: Pediatric Sleep Questionnaire-Sleep-Related Breathing Disorder, CSHQ: Children's Sleep Habits Questionnaire, CAS-15: Clinical Assessment Score-15 and SCR: Sleep Clinical Record) in screening of OSA in DS population.

Study design: Prospective study concerning children with Down syndrome (age 1-18y). Parents will complete two sleep symptom questionnaires (PSQ-SRBD and CSHQ) and children will be evaluated by a paediatric pulmonologist and allergist with skin allergy test. An Ear, Nose and Throat specialist will complete two questionnaires (CAS-15 and SCR) carrying a nasopharyngoscopy. Then, children will perform an overnight polysomnography in the Department of Paediatric Functional Investigations of University Hospital in Nice.

Inclusion Criteria:

• Age under 18 years
• Down syndrome with cytogenetic diagnosis
• State health cover
• Consent of legal representative and/or patient

Exclusion Criteria:

• Polysomnography with correct results during the 12 months before