论文部分内容阅读
目的总结脊髓小脑共济失调7型(SCA7)的临床表现,开展基因检测。方法对1个表现为视力下降、辨色力异常和行走不稳的家系完成家系调查及体格检查,部分成员行视网膜形态学及电生理检查;19名家系成员及12名健康对照者行 SCA7突变基因 PCR,测序仪直接检测三核苷酸胞嘧啶-腺嘌呤-鸟嘌呤(CAG)重复数目。结果 6例成员存存小脑性共济失调、视力下降和辨色力异常,眼底示黄斑及视网膜周边色素异常,视网膜电图波形熄灭,震荡电位幅值和光闪视觉诱发电位振幅明显下降;正常等位基因 CAG 重复数目为8～25次,该6例异常等位基因 CAG 重复数目为50～97次,诊断为 SCA7患者;1例无异常临床表现的成员 CAG 重复数日分别为18次和56次,后者超出正常范围,诊断为未到发病年龄的症状前患者。结论 SCA7患者的临床表现具有异质性,CAG 重复数目检测可以为基因诊断和症状前诊断提供依据。
Objective To summarize the clinical manifestations of spinocerebellar ataxia type 7 (SCA7) and carry out genetic testing. Methods One pediatric pedigree with visual acuity, abnormal color discrimination and ambulation was completed pedigree investigation and physical examination. Some members underwent retinal morphological and electrophysiological examination. Nineteen pedigree members and 12 healthy controls underwent SCA7 mutation Gene PCR, sequencer direct detection of trinucleotide cytosine-adenine-guanine (CAG) repeat number. Results Six patients had cerebellar ataxia, decreased visual acuity and abnormal color discrimination. The macular and retinal pigment epithelium were abnormal in the fundus, the waveform of electrocautery was extinguished, the amplitudes of oscillatory potentials and light-flash visual evoked potentials were significantly decreased. Normal and others The number of CAG repeat was 8 to 25 times and the number of abnormal CAG repeat in 6 cases was 50 to 97. The number of repeat CAG in one case with no abnormal clinical manifestations was 18 and 56 respectively Times, the latter is beyond the normal range, diagnosed as patients before onset of symptoms of the symptoms. Conclusion The clinical manifestations of patients with SCA7 are heterogeneous. The detection of CAG repeat number can provide the basis for gene diagnosis and pre-symptomatic diagnosis.