TARDBP and amyotrophic lateral sclerosis: Here, we examined whether a C9orf72 repeat length under 30, commonly reported clinical and demographic variables, and additional genetic variants [ATXN2 intermediate repeats, SOD1, fused in sarcoma (FUS), and TAR DNA-binding protein (TARDBP)] are associated with survival in ALS patients with non-pathological C9orf72 repeats.