ATXN10 and Seizure: While the expansion was originally assumed to consist of a pure expansion sequence, subsequent studies have identified interruption motifs at the 5’ and 3’ ends of the SCA10 expansion in a small subset of SCA10 patients [3, 4] We postulate that these interruption motifs act as phenotypic modifiers, as they correlate with an increased chance of having epileptic seizures in addition to typical ataxic symptoms.