Recent advancements in plasma measurements of phosphorylated tau show high sensitivity and specificity for Alzheimer’s disease pathology, correlate with in vivo CSF and PET measures of phosphorylated tau, correlate with tau neurofibrillary tangle burden at autopsy and differentiate Alzheimer’s disease from other dementia syndromes.4–7. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.