HTT and early-onset autosomal dominant Alzheimer disease: This mechanism has been extensively investigated in other neurodegenerative diseases with aggregate-prone proteins including tau in Alzheimer’s disease (Abounit et al. 2016b; Chastagner 2020), huntingtin in Huntington’s disease (Costanzo et al. 2013), and alpha synuclein in Parkinson’s disease (Abounit et al. 2016a; Dieriks et al. 2017; Rostami et al. 2017).