General description

Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant neurodegenerative disorder caused by an abnormal CAG triplet repeat expansion in the TATA-binding protein (TBP) gene. The disease typically manifests in the 30s.

SCA17 is characterized by a complex clinical phenotype comprising a constellation of neurological deficits. The core features include cerebellar ataxia, cognitive impairment progressing to dementia, extrapyramidal manifestations such as Parkinsonism and dystonia, and a propensity for seizure activity. Notably, a substantial proportion of patients (approximately 20%) exhibit Huntington's disease-like involuntary choreiform movements. This distinctive clinical presentation of SCA17, marked by the presence of chorea, has led to its classification as Huntington's disease-like syndrome 4 (HDL4) within the broader category of Huntington's disease-like (HDL) syndromes.

References

1. Kurokawa, Ryo, et al. "Clinical and neuroimaging review of triplet repeat diseases." Japanese Journal of Radiology 41.2 (2023): 115-130.