7. Participant has molecularly-confirmed, symptomatic SCA7, as defined by CAG repeat expansion in the ATXN7 gene of greater than 35 repeats. Accrual will be biased towards those with lower numbers of abnormal repeats (above 35 repeats) as they are most likely to be able to cooperate with testing. Participants who have clinical findings consistent with SCA7 and a relative who has had molecular diagnosis, may be included in the study with subsequent confirmation of the number of repeats. Patients who have clinical findings consistent with SCA7 but no molecular diagnosis may be evaluated under an NEI screening, genetics bank, or evaluation and treatment protocol with subsequent molecular diagnosis performed within six months of their initial visit.