The scientific interest in this enzyme started in 2004 when two independent groups found that recessive and dominant mutations of SETX gene are responsible for the pathology of two distinct neurological disorders: AOA2 (ataxia with oculomotor apraxia - type 2) [25] and ALS4 (juvenile Amyotrophic Lateral Sclerosis) [26], respectively. The gene discussed is SETX; the disease is juvenile amyotrophic lateral sclerosis.