Case report: A 50-year-old man with Down syndrome showing no Alzheimer's disease biomarkers or cognitive decline

This case report describes an unusual presentation of a 50-year-old Down syndrome patient who did not develop typical Alzheimer's disease biomarkers or cognitive impairment, contrary to the high prevalence of early-onset dementia in this population. The findings contribute to understanding variable neurodegeneration trajectories in Down syndrome and suggest individual genetic or protective factors may influence Alzheimer's disease risk.