Various mutations in the SIGMAR1 gene were identified in affected individuals, including a mutation (c.67251G > T) in the 3′-untranslated region in the FTLD-MND pedigree and mutations (c.304G > C, c.67231A > G, c.505 T > A, c.622C > T, c.283dupC, c.58 T > C, c.125 > G) in the SIGMAR1 gene in affected ALS patients. Here, SIGMAR1 is linked to mild neurocognitive disorder.