Further investigation for MCI includes cerebrospinal fluid (CSF) analysis, for detection of Aβ1–42 and phosphorylated tau (p-tau) increased levels, reflecting the presence of senile amyloid plaques and neurofibrillary tangles in the brain, and predicting the MCI conversion to Alzheimer’s Disease [6]. The gene discussed is MAPT; the disease is early-onset autosomal dominant Alzheimer disease.