ATXN10 and Ataxia: Other shorter ATXN10 expansions have been reported with reduced penetrance up to 850 pentanucleotide repeats.21, 22 One SCA10 case (subject A32) has been described with an age at onset of ataxia and non-levodopa-responsive parkinsonian features at 83 and 1400 ATXN10 repeat expansions;13, 32 therefore, we cannot exclude that this sibling might be presymptomatic and might develop symptoms of SCA or parkinsonian at a later age.