脊髓小脑性共济失调3型、7型患者三家系的临床表现和基因突变

目的 探讨脊髓小脑性共济失调3型、7型的基因突变特点及临床表现.方法 总结3个家系中13例患者的临床表现,对13例患者、4例＂健康＂成员和4例普通成员,采用PCR法、琼脂糖凝胶电泳检测扩增产物、基因测序等技术分析SCA3、7型基因内CAG三核苷酸重复序列的长度和扩增数.结果 1个家系中4例患者存在SCA3/MJD（CAG）n扩增突变,CAG重复数为65～74次;2个家系中9例患者存在SCA7（CAG）n扩增突变,CAG重复数为40～52次.两亚型在神经系统受累部位等方面存在差异.结论 SCA3/MJD和SCA7型患者临床表现存在一定的差异,有利于鉴别及分型,但是基因检测是SCA患者确诊的唯一有效的诊断方法.

The clinical feature and gene mutation of three pedigrees with spinocerebellar ataxia MA

Objective To investigate the clinical features and the gene mutation of patients with spinocerebellar ataxia type3 and type7.Methods The trinucleotide repeat mutations were detected by polymerase chain reaction (PCR),agarose gel electrophoresis method,and DNA sequencing in 13 patients,4 related members and 4 common members from 3 spinocerebellar ataxia families.Results Among the 13 patients,four patients had SCA3/MJD(CAG) n expansion mutation(n = 65 ～ 74),nine patients had SCA7 allele expansion for 40 ～ 52 times.Patients with type 3 or 7 showed significant difference in nervous system injury.Conclusion The difference of clinical feature might be used in diagnosis of SCA3/MJD and SCA7,but genotype determination would be the only method of definite diagnosis.