Mutations in SETX transmitted in an AD manner are involved in amyotrophic lateral sclerosis-4 (ALS4), and with an AR mode of inheritance, are responsible for SCA with axonal neuropathy (SCAN2), which is characterised by progressive CA, along with sensorimotor neuropathy, occasional oculocephalic dissociation and/or oculomotor apraxia, strabismus, chorea, dystonia, and elevated serum α-fetoprotein levels [28,29]. This evidence concerns the gene SETX and Chorea.