MAPT and early-onset autosomal dominant Alzheimer disease: Amyloid and tau are hallmark pathologies of Alzheimer’s disease1,2 and have been identified as core biomarkers for Alzheimer’s disease diagnosis, according to the most recent diagnostic criteria published by the Alzheimer’s Association.3 The measurement of amyloid and tau in CSF, which demonstrates comparable performance to positron emission tomography (PET) imaging,4-6 is becoming increasingly widespread for Alzheimer’s disease diagnosis.