Presently, the diagnosis of SAD/LOAD is based upon detecting brain deposits of insoluble Aβs (senile plaques) via PET imaging and specific changes in Aβ42/Aβ40 and Tau/p-Tau ratios values in the cerebrospinal fluid (CSF), which are deemed to be pathognomonic (McKhann 2011). The gene discussed is MAPT; the disease is Senile plaques.