ATXN3 and Rare hereditary ataxia: In Brazil, SCA3 is the most prevalent form of hereditary ataxia, followed by SCA2 and SCA10.3,4 The high prevalence of SCA3 is largely due to the Portuguese-Azorean founder effect, while SCA2 and SCA10 originate from the native American populations.3, -, 5 The ethnic diversity of the Brazilian population provides a unique opportunity to study the distribution and prevalence of GAA-FGF14 ataxia.