Instead, depending on their position, mutations in TUBB4A may cause three neurodegenerative disorders: (i) hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC), a rare hypomyelinating disease of infancy and childhood [98,99,100,201,211,212,213,214,215,216,217,218] (ii) hereditary spastic paraplegia [96,97,98]; (iii) DYT4 with whispering dysphonia and normal MRI [96,97,98]. Here, TUBB4A is linked to hereditary spastic paraplegia.