RAN translation has been detected in many repeat expansion disorders (e.g., Amyotrophic Lateral Sclerosis and Frontotemporal Dementia (ALS-FTD) with expanded GGGGCC repeats, Spinocerebellar Ataxia Type 8 (SCA8) with CAG repeats, and FXTAS with CGG repeats (Zu et al., 2011; Sellier et al., 2013), suggesting an essential role of the shared RAN translation mechanism in disorders caused by various repeat expansion. This evidence concerns the gene RAN and fragile X-associated tremor/ataxia syndrome.