Down syndrome is a central research topic in genetics, medicine, and developmental sciences, focused on investigating the etiology of trisomy 21, the associated phenotypic spectrum, developmental trajectories, and effective strategies for diagnosis, clinical management, and support across the lifespan. This multidisciplinary field encompasses studies of genetic mechanisms, neurobiological correlates, cognitive development, health comorbidities, educational interventions, and social outcomes, contributing significantly to understanding human chromosome abnormalities and informing clinical practice and support services.