Lysosomal abnormality, typically accompanied by lysosomal morphology remarkably similar to that observed in this study, has already been described in several rare HSP subtypes involving proteins that localize to endosomes, including SPG11, SPG15, and AP5 complex members (Khundadze et al., 2013; Renvoisé et al., 2014; Hirst et al., 2015; Varga et al., 2015). The gene discussed is AP5B1; the disease is hereditary spastic paraplegia.