| To explore the clinical features of spinocerebellar ataxia type 3 (SCA3) characterized by
tremor as the main feature, and to analyze a family with extrapyramidal signs such as tremor and peripheral
neuropathy, providing a basis for clinical diagnosis. Methods: Ten SCA3 patients characterized by tremor were
collected, including 4 from the same family. The clinical features, imaging, genetic testing, and drug
responsiveness of 6 non-family patients, 4 familial patients, and their family members (5 cases) were
summarized, along with a review of related literature. Results: Among the 9 patients in the family, 4 were
diagnosed through genetic testing (ATXN3 gene CAG repeats 57～58 times, Sanger validation 60～62 times),
and 5 were suspected patients. Among the 4 confirmed cases, 2 presented with tremor as the main symptom
(postural/action tremor, exacerbated by activity), 1 was accompanied by bradykinesia and a history of epilepsy,
and 1 had peripheral neuropathy. No significant atrophy was observed on brain MRI. Compared with typical
SCA3 patients with CAG repeats 66～73 times (mainly ataxia), tremor symptoms were significant in this family,
partially relieved by Madopar treatment. Conclusion: The clinical phenotype of SCA3 may be related to the
number of CAG repeats (60～62 repeats mainly presenting as tremor/bradykinesia, 66～73 repeats mainly as
ataxia). It is necessary to pay attention to the identification of atypical symptoms, with genetic testing being
crucial for diagnosis. |