TFG and neuropathy, hereditary motor and sensory, type 6A: On the other hand, TFG was recently identified as a causative gene for several neurodegenerative diseases, such as hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P)6–8, the axonal type of Charcot-Marie-Tooth disease9 and hereditary spastic paraplegia (HSP)10–12.