TRISOMY 21 AND ALZHEIMER'S DISEASE: MOLECULAR MECHANISMS, EARLY DIAGNOSIS, AND PREVENTION PROSPECTS

Trisomy 21 is a genetic condition characterized by the presence of an additional copy of chromosome 21 and its associated genes. One of the major consequences of trisomy 21 is an increased susceptibility to neurodegenerative changes associated with Alzheimer's disease. Increased gene dosage of APP, which encodes amyloid precursor protein, plays a central role by promoting the production and accumulation of β-amyloid in the brain. Additional mechanisms include alterations in tau regulation, oxidative stress, neuroinflammation, impaired endosomal trafficking and other effects related to genes located on chromosome 21. Current research demonstrates the potential value of plasma biomarkers, including β-amyloid, phosphorylated tau, and neurofilament light chain, for the early detection of pathological changes. However, the diagnostic performance of individual biomarkers varies and their clinical implementation requires further standardization. Understanding the molecular mechanisms linking trisomy 21 and Alzheimer's disease may contribute to the development of earlier diagnostic approaches and potentially targeted preventive and therapeutic strategies.