Similar to our findings in this cohort of presymptomatic patients, a study of symptomatic C9orf72 patients with ALS fulfilling the EL Escorial criteria [69] also identified the selective degeneration of thalamic nuclei in C9orf72-positive ALS preferentially involving the mediodorsal–parateniual–reuniens group of nuclei, which play a central role in executive processes. Here, C9orf72 is linked to amyotrophic lateral sclerosis.