Elevated levels of total tau (t-TAU) and phosphorylated tau (p-TAU) in CSF indicate both axonal and neuronal damage in many neurological disorders, such as Alzheimer’s disease (AD), traumatic brain injury (TBI), acute ischemic stroke (AIS), viral encephalitis, and Creutzfeldt–Jakob disease (CJD) [1]. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.