MAPT and frontotemporal dementia: No other causative mutations associated with ALS were identified in the case 1, while the exome sequencing revealed some variants of benign or uncertain significance including c.1321T>C (p.Y441H) in the MAPT gene associated with frontotemporal dementia, c.475G>A (p.E159K) in the ALS2 gene associated with juvenile‐onset ALS, c.1844C>T (p.P615L) in the NEFH gene associated with Charcot–Marie–Tooth disease, and c.4445C>T (p.T1482I) in the TRPM7 gene associated with ALS/parkinsonism/dementia susceptibility complex 1 (Table S2).