One study reported the co-occurrence of CHCHD10 and C9orf72 variants in an ALS-FTD patient (53), and another reported a person carrying both TBK1 and SQSTM1 variants, who was diagnosed with non-fluent variant primary progressive aphasia (nfv-PPA) (54). Here, C9orf72 is linked to amyotrophic lateral sclerosis.