TBK1 and frontotemporal dementia: The frequency of TBK1 LoF mutations in sporadic ALS ± FTD in the Chinese population is similar to the frequency of the Japanese population (0.42%, 3/713), lower than the frequency of the Korean population (0.78%, 1/129) and the European populations (1.7%, 11/665) (van der Zee et al., 2017).