Senataxin (SETX) gene mutations are known to cause ataxia with oculomotor apraxia type 2 (an autosomal recessive cerebellar ataxia with onset between age three and 30 years after initial normal development, axonal sensorimotor neuropathy, oculomotor apraxia, cerebellar atrophy, and elevated serum concentration of α-fetoprotein) and juvenile amyotrophic lateral sclerosis type 4 (an autosomal dominant amyotrophic lateral sclerosis with mean age of onset at 17 years, slowly progressive distal amyotrophy, pyramidal signs, normal sensory examination, and lack of bulbar involvement). The gene discussed is SETX; the disease is Ataxia.