ATXN3 and autosomal recessive cerebellar ataxia: Among non-controlled studies, the trial by Santos et al., the largest one [29], which was also the one with the lowest quality score, enrolled 28 subjects with undefined SCA (n = 7), SCA3 (n = 5), SCA10 (n = 5), SCA2 (n = 2), SCA4 (n = 1), and autosomal-recessive cerebellar ataxia (ARCA) (n = 8).