Dominant mutations in SETX cause juvenile-onset amyotrophic lateral sclerosis type 4 (ALS4), while recessive mutations are associated with ataxia-oculomotor apraxia 2 (AOA2) characterized by cerebellar ataxia, oculomotor apraxia, and axonal sensorimotor neuropathy [57,59]. Here, SETX is linked to spinocerebellar ataxia, autosomal recessive, with axonal neuropathy 2.