Tau isoform imbalance is thought to be mechanistically linked to neurodegenerative diseases, such as Alzheimer’s disease (AD) (3R and 4R tau), progressive supranuclear palsy (PSP) (4R tau), and Pick’s disease (PiD) (3R Tau) [1], with recent studies demonstrating that imbalance in tau isoform expression can lead to different forms of neurodegeneration [3–5]. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.