The present study sought to provide a preliminary examination of OSA and sleep disruptions using an objective home sleep test in a sample of 81 adults with DS (aged 25–61 years) and evaluated their associations with PET Aβ and tau burden and direct and informant-based measures of early AD symptomatology, which have been previously shown to include impairments in memory, executive functioning, and motor planning and control and depressed mood [21–23]. Here, MAPT is linked to Alzheimer disease.