REEP2 and Troyer syndrome: Within the Cytoscape network, other causative genes for HSP were strongly connected to REEP1, REEP2, and REEP5. These were spartin (SPG20), spastin (SPAST), atlastin (ATL1), non-imprinted in Prader-Willi/Angelman syndrome-1 (NIPA1), and reticulon-2 (RTN2), causative for Troyer syndrome, autosomal dominant spastic paraplegia 4, autosomal dominant spastic paraplegia 3A, autosomal dominant spastic paraplegia 6, and autosomal dominant spastic paraplegia 12, respectively (Reed et al., 2005; Shoukier et al., 2009; Montenegro et al., 2012; Varga et al., 2013; Bizzari et al., 2017).