Similar pathogenic mechanisms have been proposed for other repeat expansion disorders, such as Fuchs’ endothelial corneal dystrophy [71,72], Huntington’s disease [73‒75], and C9orf72-mediated amyotrophic lateral sclerosis/frontotemporal dementia (C9-ALS/FTD) [76‒78]. Here, C9orf72 is linked to frontotemporal dementia.