Co-occurring conditions in Down syndrome: Findings from a clinical database.

Individuals with Down syndrome (DS) experience a range of medical and neurodevelopmental conditions, necessitating systematic study of their occurrence and impact on neurodevelopmental outcomes. We describe the prevalence and relationships of medical, neurodevelopmental (ND), and mental health (MH) conditions in children with DS. We created a prospective clinical database of individuals with DS, integrated into the workflow of a specialty Down Syndrome Program at a specialty pediatric referral hospital. Conditions were collected through caregiver- and clinician report at clinical visits (N = 599). We calculated frequencies of medical, ND, and MH conditions and then assessed the relationship between medical, ND, and MH conditions using frequencies and comparative statistics. The most frequent co-occurring conditions were vision (72.5%), ear/hearing (71.0%), gastrointestinal (61.3%), respiratory (45.6%), and feeding (33.6%) problems, with variation in frequency by age. ND and MH conditions were reported in one quarter, most commonly autism spectrum disorder and attention-deficit/hyperactivity disorder. Those with ND and MH conditions had greater frequency of medical conditions, with highest rates of vision, ear/hearing, and gastrointestinal issues, and CHD. Systematically collected clinical data in a large cohort of children with DS reveals high prevalence of several co-occurring medical, ND, and MH conditions. Clinical care requires an understanding of the complex relationship between medical conditions and neurodevelopment.