The study aims were: (1) to characterize real-life sleep disruptions and sleep-disordered breathing in a cohort of adults with DS to understand the prevalence, under-detection, and under-treatment of OSA and its association with sociodemographic variables; and (2) examine the relation between sleep disruptions and sleep-disordered breathing and AD pathology (PET Aβ and tau) and symptomatology (cognitive performance and depressed mood). The gene discussed is MAPT; the disease is Alzheimer disease.