MAPT and Alzheimer disease: The PGRS for AD was unrelated to amyloidosis or neurodegeneration, but did show an association with SNAP defined using CSF tau (F(3,518) = 2.76, p = 0.04) whereby the Aβ-42-/Tau+ group (p = 0.02) and the combined Aβ-42+/Tau+ group (p = 0.04) had higher PGRS than the biomarker negative group.