Down Syndrome

Down syndrome is a genetic cause of intellectual disability that predisposes individuals to distinct physical and clinical profiles. While there are commonalities in physical features, slower rates of growth, and neurodevelopmental delays among individuals with Down syndrome, there is also significant heterogeneity. Individuals with Down syndrome are at higher risk of developing some co-occurring medical and mental health conditions, and at lower risk of developing others. This chapter reviews the etiology and prevalence of Down syndrome, the impact of neurobiology on cognition, language, and motor development primarily focused on childhood and adolescence, and advances in intervention and educational supports specific to individuals with Down syndrome. Common co-occurring medical and mental health conditions among individuals with Down syndrome are reviewed. Given the increased lifespan experienced by individuals with Down syndrome in recent decades, the chapter reviews factors related to adulthood in Down syndrome, specifically focused on health, employment, and enhancing healthy aging. The chapter concludes by discussing the family system in the context of having a family member with Down syndrome and the role of community engagement in the lives of individuals with Down syndrome.