河南地区遗传性脊髓小脑共济失调3型患者临床特征及分子生物学的研究  

Research on clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 3 in Henan province of China

作　　者：李学[1] 王泽帅[2] 马建军[1] 

机构地区：[1]河南省人民医院神经内科,河南郑州450003 [2]郑州市中心医院神经内科,河南郑州450003

出　　处：《临床荟萃》2010年第14期1197-1200,共4页Clinical Focus

基　　金：河南省科技攻关项目(200703093)

摘　　要：目的探讨河南地区汉族人群中遗传性脊髓小脑共济失调3型（spinocerebellar ataxia type 3,SCA3）患者临床表现与分子生物学的特征。方法应用聚合酶链反应（PCR）、琼脂糖凝胶电泳和基因测序等技术,检测临床诊断脊髓小脑型共济失调（spinocerebellar ataxia type,SCA）的9个家系55例患者SCA3基因内CAG三核苷酸重复序列,并对异常等位基因片段进行DNA测序。结果检出2个家系（10例患者）为SCA3,阳性率17.1%,测序证实其异常等位基因的CAG重复数目在70~79次之间,平均重复数（74.2±3.8）次。测序发现SCA3基因在重复起始序列的第3、4、6拷贝位置出现变异,CAG分别由CAA、AAG和CAA替代。SCA3基因中在重复起始序列的第3、4、6拷贝位置出现变异,CAG分别由CAA、AAG和CAA替代。结论 CAG重复数检测是确定患者基因突变的重要证据;CAG重复序列的异常扩增是SCA3患者基因突变的重要原因。Objective To study the clinical characteristics and molecular biology of hereditary spinocerebellar ataxia type 3（SCA3） in Henan province of China.Methods The SCA3（CAG） ntrinucleotide repeat mutations were detected using polymerase chain reaction（PCR） and polyacrylamide gel electrophoresis（PAGE） technique in 55 patients with autosomal dominant SCA from 9 families.The abnormal allele fragments were sequenced by DNA sequencing machine.Results Two SCA families（10 patients） had abnormal SCA3 alleles with the CAG repeat expanded to 70 and 79 repeats respectively,as confirmed by DNA sequencing,of which 17.1% was the positive rate.There were variations in the initial sequence of the first duplicate copy 3,4,6 locations in SCA3/MJD gene,and CAG replaced by CAA,AAG and CAA respectively.Conclusion The detection of repeat number on CAG was essential evidence to determine the gene mutation in patients.CAG expansions were suggested as the pathogenic cause of SCA3.

关 键 词：脊髓小脑共济失调 体征和症状 系普 

分 类 号：R742.822[医药卫生—神经病学与精神病学]