FGF14 and Friedreich ataxia: Although the prevalence of vestibular impairment in spinocerebellar ataxias has not been well studied, this feature is not specific to GAA-FGF14-related disease, as it is found with variable frequency in other inherited ataxias such as RFC1-related disease (87–90%),5 6 Friedreich ataxia (53–55%)12 13 and spinocerebellar ataxia 3 (57–100%).14–16