MAPT and early-onset autosomal dominant Alzheimer disease: Whilst biomarkers of the molecular pathology of Alzheimer’s disease, including CSF analysis of amyloid-β, tau and phosphorylated tau (Ewerset al., 2015), or amyloid PET (Jacket al., 2013), are available in some expert centres, logistical challenges and financial constraints limit their adoption into routine clinical use at this time.