“…In both symptomatic and presymptomatic APP , PSEN1 and PSEN2 mutation carriers, the majority of the studies found a decrease in Aβ 42 and an increase in both t-tau and p-tau levels when compared with healthy control individuals, consistent with a typical AD profile [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26] (table 1). In some cases, 1 or more markers were found to be unchanged compared to controls [27,28,29,30].…”