The purpose of this study is to describe infectious and non-infectious lower respiratory tract diseases in children with Down syndrome followed in pediatric pulmonology consultations in Ile de France.

Down syndrome is the most common chromosomal abnormality, affecting 600 to 800 births per year. It results in a clinical picture that combines developmental delay, mental deficiency, facial dysmorphism and visceral malformations.

Optimal medical care of Down syndrome patients requires a good knowledge of the different systems affected by the disease, particularly respiratory damage.

Numerous articles have been published describing upper respiratory problems in children with Down syndrome. On the other hand, lower respiratory problems causing significant morbidity and mortality remain underestimated and poorly understood in this population.

The objective of this study is to describe lower respiratory problems in patients with T21, in order to improve their management.

This study will also make it possible to describe more precisely the impact that these attacks have on Down syndrome patients.

This study also describe the associated extra-respiratory disorders to improve overall care Finally, the respiratory care of these patients will be described, with the aim of standardizing practices.

Inclusion Criteria:

• Child from 0 to 17 years old
• Carrier of Down syndrome confirmed by karyotype
• Having had follow-up in a pediatric pulmonology consultation for an infectious or non-infectious lower respiratory tract
• Not exclusively presenting upper respiratory otorhinolaryngological damage

Exclusion Criteria:

• Patient under guardianship or curators
• Adult or holders of parental authority informed of the study and having objected to it

children with Down syndrome, who were hospitalized for respiratory problems and who had subsequent pediatric pulmonology follow-up between 2013 and 2023