MAPT and Alzheimer disease: This fits with the accepted notion that the disease is more aggressive when contracted earlier in life (van der Flier et al., 2011), and with cross-sectional studies that have shown greater cortical tau uptake in young compared to old onset AD (Cho et al., 2017; Lowe et al., 2018; Scholl et al., 2017; Tetzloff et al., 2018).