MAPT and Alzheimer disease: From a neuropathological perspective, AD is characterized by the deposition of extracellular amyloid-β (Aβ)-containing plaques and the formation of intraneuronal tau tangle aggregates with a pre-symptomatic phase up to 20 years.4, 5 Cerebrospinal fluid (CSF) assays for AD biomarkers and amyloid positron emission tomography (PET) are clinically used to assist the diagnosis of AD, but their high cost and invasive nature limit their utility, particularly in LMICs5.