两遗传性脊髓小脑型共济失调7型家系的临床特征和基因突变研究  

Clinical characteristics and gene mutation analysis of hereditary spinocerebellar ataxia type 7： a study of 2 Chinese families

作　　者：朱海英[1] 马英文[2] 冯光坤[2] 王勤周[2] 毕建忠[1] 

机构地区：[1]山东大学第二医院神经内科,济南250021 [2]济南市第四人民医院神经内科,250031

出　　处：《中华神经医学杂志》2010年第10期1042-1044,共3页Chinese Journal of Neuromedicine

摘　　要：目的探讨遗传性脊髓小脑型共济失调（SCA）7型（SCA7）的临床特征和基因突变。方法采用聚合酶链反应（PCR）和琼脂糖凝胶电泳（AGE）等技术，检测临床诊断为SCA的5个家系26例患者和37例表型正常的家系成员的SCA7基因内CAG三核苷酸重复次数，对异常等位基因片段进行DNA测序，分析临床表现和基因突变的关系。结果2个SCA7家系患者的SCA7等位基因内CAG重复数目为44～50次；临床表现主要为共济失调、视力下降及视网膜色素变性。该家系内表型正常的家系成员SCA7等位基因CAG重复数目为10～30。结论CAG过度扩增为SCA7的致病原因．分子遗传学分析有助于SCA7的诊断。Objective To study the clinical characteristics and gene mutation of hereditary spinocerebellar ataxia type 7 （SCAT）. Methods The regions of SCA 7 gene containing CAG repeat were amplified by means of PCR and agarose gelelectrophoresis （AGE） technique in 26 patients and 37 normal family members from 5 families with autosomal dominant SCA. The abnormal allele fragments were sequenced by DNA sequencing machine. The correlation between clinical manifestations and CAG repeat size in SCA 7 gene product was analyzed. Results The patients carried 44-50 repeated CAG in the SCA7 allele of 2 SCA 7 gene families with main clinical manifestations as ataxia, hypopsia and retinal pigmental degeneration. About 10-30 repeated CAGs in the SCAT allele were seen in other healthy members. Conclusion Expanded triplet repeats in SCA 7 gene contributes to the pathologic phenotype, and molecular genetic analysis is effective in the diagnosis and differentiation ofSCA 7 gene.

关 键 词：脊髓小脑共济失调 等位基因 三核苷酸重复 视网膜色素变性 

分 类 号：R686[医药卫生—骨科学]