SPG11 and hereditary spastic paraplegia: Here, we discuss the three forms in which autophagy impairment has been described: HSP caused by mutations in SPG11, SPG15, and SPG49. Almost one third of complex HSP cases involve alterations in the corpus callosum, and 70% of these are due to mutations in SPG15/ZFYVE26 or SPG11/KIAA1840 [146].