Paparella Giulia, De Riggi Martina, Aloisio Simone, Martini Adriana, Angelini Luca, Birreci Daniele, Costa Davide, Cannavacciuolo Antonio, Griguoli Anna Maria, Gambardella Stefano, Bologna Matteo
Department of Human Neurosciences, Sapienza University of Rome, Rome, Italy.
IRCCS Neuromed, Pozzilli (IS), Italy.
Cerebellum. 2025 Jun 6;24(4):110. doi: 10.1007/s12311-025-01868-1.
Spinocerebellar ataxia type 17 (SCA17) is an autosomal dominant disease caused by a polyglutamine-encoding CAG/CAA repeat expansion within the TATA box-binding protein (TBP) gene. It is characterized by a markedly heterogeneous phenomenology and complex genotype-phenotype relationships.
We describe the clinical, neuropsychological, and neuroimaging findings of a 73-year-old patient who presented a 10-year history of generalized hyperkinetic movements and depressive symptoms. The patient's family history was unremarkable. Neurological examination revealed choreic movements affecting the upper and lower limbs, the face and the trunk with no additional neurological signs. Blood sample analysis, brain imaging, and neuropsychological evaluation revealed normal results. Genetic analysis identified, in the TBP gene, the 41-CAG pathological allele with reduced penetrance.
The present case report provides further insight into the small-expanded allele SCA17-associated phenotype, supporting the recently updated genotype-phenotype assessment for SCA17.
17型脊髓小脑共济失调（SCA17）是一种常染色体显性疾病，由TATA盒结合蛋白（TBP）基因内编码多聚谷氨酰胺的CAG/CAA重复序列扩增引起。其特点是临床表现明显异质性，基因型与表型关系复杂。
我们描述了一名73岁患者的临床、神经心理学和神经影像学检查结果，该患者有10年的全身性运动过多和抑郁症状病史。患者家族史无异常。神经系统检查发现肢体、面部和躯干出现舞蹈样动作，无其他神经系统体征。血液样本分析、脑部成像和神经心理学评估结果均正常。基因分析在TBP基因中鉴定出41-CAG病理性等位基因，其外显率降低。
本病例报告进一步深入了解了小扩增等位基因SCA17相关表型，支持了最近更新的SCA17基因型-表型评估。
