【关键词】 脊髓小脑共济失调；基因分型；临床表现；诊断

    【摘 要】 目的 探讨北方地区人群中脊髓小脑共济失调(SCA)3种亚型的发生率以及各型临床表现的特征，并进行基因分型。方法 应用PCR方法和琼脂糖凝胶电泳对92例不明原因共济失调先证患者测定其SCA1、SCA2和SCA3基因片段长度。结果 在92例患者中共检测出SCA患者21例，占被检测人数的22.8%。其中SCA3型最多，共16例，占17.4%；其次为SCA2型4例，占4.3%；SCA1型只检测出1例，占1.1%。各型间的发病年龄无明显差异。临床表现相互重叠，肌张力障碍、眼动障碍和锥体束征主要见于SCA3。发现1例以帕金森为表现的SCA2型患者。结论 通过这次研究，发现SCA1、SCA2、SCA3型在不明原因的共济失调中的发生率为22.8%，其中又以SCA3型为主，确定诊断的最直接最有效的手段是基因诊断。

    Clinical characteristics and genetic typing of types 1，2，and 3 spinocerebeller ataxia

    SONG Yang,CHEN Biao,WEN Mei.

    Xuanwu Hospital, Capital Medical University,Beijing 100053,China

    【Abstract】 Objective To investigate clinical features,incidence and genetic typing of types 1，2，and 3 spinocerebeller ataxia (SCA) in 92 patients.Methods The length of genetic segment of SCA1,SCA2 and SCA3 in 92 patients with ataxia of unknown origin were detected by polymerase chain reaction (PCR) and agarose gel electrophoresis .Results Among 92 patients,21 patients (22.85%) were identified as spinocerebeller ataxia including 16 cases of SCA3 (17.4),4 cases of SCA2 (4.3%) and 1 case of SCA3 (1.1%).There was no significant difference in patient's age among different types.The main clinical characteristics of SCA3 were disorder of muscular tension, disturbance of moving eyes and pyramidal tract syndrome.There was a patient whose clinical manifestation was Parkinson's syndrome.Conclusion The incidence of SCA1,SCA2 and SCA3 is 22.8% in patients with ataxia of unknown origin, and SCA3 is main type. Genetic analysis is the most effective means for the diagnosis of SCA. ......