摘要目的 探讨脊髓小脑共济失调17型(spinocerebellar ataxia 17,SCA17)患者的临床特征和基因突变的特点.方法 对708个常染色体显性遗传SCA家系的先证者和另外119例临床拟诊SCA的散发患者进行常规基因检测,按照患病率不同依次筛选:SCA3、SCA1、SCA2、SCA6、SCA7、SCA8、SCA12、SCA17、齿状核-红核-苍白球-路易体萎缩致病基因三核苷酸重复动态突变分析.其中SCA17致病基因检测采用聚合酶链反应扩增TATA结合蛋白(TBP)基因CAG重复序列,琼脂糖凝胶电泳检测扩增产物；对出现2个电泳条带的样品应用毛细管电泳片段分析方法进行TBP基因CAG重复次数检测,并对其临床表型、神经影像学特征以及表型与基因型相关性进行细致分析.结果 通过上述检测及分析,发现5例患者具有TBP基因CAG重复扩展突变.片段分析显示CAG重复次数分别为37/50、36/45、38/52、38/53、36/54次,长片段重复次数已达到异常范围.5例患者的临床表型各异,以共济失调、记忆力减退为主要症状.结论 在827例共济失调病例中仅发现5例SCA17,说明该病在中国人群中较为罕见；通过对5例患者的临床表型进行分析,初步认为国人SCA17存在临床变异.

abstractsObjective To investigate the clinical features and genetic mutations of spinocerebellar ataxia type 17 (SCA17).Methods The pathological CAG triplet repeat expansions of the SCA3,SCA1,SCA2,SCA6,SCA7,SCA8,SCA12,SCA17 and dentatorubral pallidoluysian atrophy genes were analyzed in 708 probands of autosomal dominant familial SCA and 1 19 sporadic SCA cases.The CAG repeats of TATA-binding protein (TBP) gene were amplified by means of polymerase chain reaction and agarose gel electrophoresis.For the samples with two alleles,fragment analysis based on CEQ8000 sequencer was applied to analyze the CAG repeat numbers.Furthermore,the correlation between clinical features and CAG repeat in the TBP gene was studied carefully.Results The expanded CAG repeats in the TBP gene was detected in 5 cases with 37/50,36/45,38/52,38/53,36/54 separately.And the main clinical manifestations were ataxia and memory impairment.Conclusion These findings indicate that SCA17 might be a rare subtype of SCA in the Chinese population and the clinical features of SCA17 cover a wider spectrum than previously reviewed.