Genetic risk factors of late-onset Alzheimer’s disease: Insights into pathophysiology and emerging therapeutic directions

Late-onset Alzheimer's disease is a devastating and complex neurodegenerative disorder with a multifactorial etiology. Over the past decade, advances in genetic research have identified novel risk genes, shedding light on the underlying pathogenic mechanisms of late-onset Alzheimer's disease. This review provides a comprehensive overview of several of these crucial genetic factors and their potential mechanisms in the pathogenesis of Alzheimer's disease. Genome-wide association studies, whole-genome sequencing, and multi-omics studies have played a crucial role in identifying key risk genes, particularly those involved in amyloid-β metabolism and clearance, such as CLU and APOE, which influence amyloid-β aggregation. Tau pathology, characterized by neurofibrillary tangles, is another hallmark of Alzheimer's disease, with genes such as BIN1 implicated in tau-mediated neurodegeneration. Additionally, immune regulatory genes, including CR1, MS4A6A, CD33, and TREM2, play crucial roles in microglial activation and neuroinflammation, thereby contributing to disease progression. Synaptic dysfunction is also a critical factor in Alzheimer's disease pathology, with genes such as IQCK, EPHA1, and CD2AP linked to synaptic function and plasticity, highlighting their potential impact on cognitive decline. Understanding these genetic risk factors provides valuable insights into the complex genetic landscape of Alzheimer's disease and its highly heterogeneous pathological mechanisms, including amyloid-β metabolism, tau pathology, immune response and neuroinflammation, and synaptic dysfunction. Future research should focus on elucidating the functional roles of these individual genes and their potential as therapeutic targets for altering the course of Alzheimer's disease.