C9orf72 and amyotrophic lateral sclerosis: The inconsistency with regard to laterality may stem from small sample sizes, but right‐sided predominance is often observed in C9orf72‐associated ALS–FTD (Agosta et al., 2017; Sha et al., 2012), and relative left‐predominance was noted in C9orf72‐associated bvFTD (Lee et al., 2014; Sha et al., 2012).