FXN and cerebellar ataxia: This classification provides insufficient guidance for physicians and researchers, so alternatives for recessive cerebellar ataxias have been generated that could be more effective, including the gene name and based on a division between phenotypes with ataxia (e.g., ATX-FXN, Friedreich ataxia), ataxia with a predominant movement disorder (e.g., ATX/HSP-HEXA, Tay-Sachs disease), or complex phenotypes that occasionally present with CA (e.g., EXOSC3, pontocerebellar hypoplasia type 1B) [15].