ATL1 and hereditary spastic paraplegia: Strikingly, mutations in the genes encoding 4 members of these classes of proteins (reticulon-2, REEP1, REEP2 and atlastin-1) are encoded by genes that are mutated in HSP (Esteves et al., 2014; Montenegro et al., 2012; Zhao et al., 2001; Zuchner et al., 2006).