FIG4 and amyotrophic lateral sclerosis: Furthermore, as with TRPML1, mutations in the human PIKfyve complex, namely the FIG4 and Vac14 components, lead to neurodegeneration – in this case, including amyotrophic lateral sclerosis (ALS), Charcot–Marie–Tooth disease, and Yunis–Varon syndrome (Campeau et al., 2013; Chow et al., 2009; Chow et al., 2007; Lines et al., 2017; Nicholson et al., 2011; Zhang et al., 2008).