There is a close overlap between idiopathic normal pressure hydrocephalus (iNPH) and Alzheimer’s disease (AD) because both conditions involve abnormal deposition of toxic byproducts of cerebral metabolism in the brain, such as amyloid-beta 1–42 (amyloid-β 1–42) and Tau protein. Here, MAPT is linked to early-onset autosomal dominant Alzheimer disease.