中文摘要：

目的：研究湖南汉族人群中脊髓小脑性共济失调（SCAs）不同基因亚型的分布状况。方法：应用聚合酶链式反应（PCR）和变性聚丙烯胺凝胶电泳以及测序技术，检测分析了139个常染色体显性遗传SCA家系和61个散发SCA患者的SCA1，SCA2，SCA3，SCA6，SCA7，SCA17，齿状核红核苍白球路易体萎缩（DRPLA）三核苷酸重复序列突变。结果：在139个SCA家系中，11个家系（7．9％）有SCA1突变，9个家系（6．5％）有SCA2突变，71个SCA家系（51.1％）有SCA3突变，4个家系（2．9％）有SCA6突变，2个家系（1．4％）有SCA7突变。未检出SCA17，DRPLA亚型。在散发患者中发现1例SCA2患者、3例SCA3患者、1例SCA6患者。结论：SCA3为最常见类型；其次为SCA1，SCA2；SCA6，SCA7患者少见。

英文摘要：

Objective To determine the frequency of different subtypes of spinocerebellar ataxias （ SCAs ） in the Han nationality of Hunan province in China. Methods The mutations of SCA 1, SCA2, SCA3,SCA6, SCA7, SCA17, and dentatorulral-pallidoluysian （ DRPLA ） were detected with the polymerase chain reaction （ PCR ） , denaturing polyacrylamide gel and DNA sequencing techniques in 139 autosomal dominant SCA families and 61 sporadic SCA patients. Results Of the 139 families,11 （7.9%） were positive for SCA1, 9（6.5%） were positive for SCA2, 71（51. 1%） were positive for SCA3, 4（2.9% ） were positive for SCA6, 2（ 1.4% ） were positive for SCA7,and none was positive for SCA 17 and DRPLA. There was in the 61 sporadic SCA patients. Conclusion 1 SCA2 patient, 3 SCA3 patients, 1 SCA6 patient The frequency of SCA3 is substantially higher than that of SCA1 and SCA2 in the autosomal dominant SCA patients in the Han nationality of Hunan province. SCA6 and SCAT are rare subtypes.