Ataxia with Oculomotor Apraxia Type 2 (AOA2) and a form of adolescent ALS (amyotrophic lateral sclerosis type 4) are caused by mutations in the Senataxin (SETX) gene, which encodes a helicase that resolves R-loops during transcription termination [69]. Here, SETX is linked to amyotrophic lateral sclerosis type 4.