一个遗传性脊髓小脑型共济失调大家系的致病基因分析  

Analysis of the genetic mutation in a Large Chinese kindred with hereditary spinocerebellar ataxia

作　　者：张淑玲[1] 张向阳[2] 李聪[2] 张萌[1] 周丽[1] 徐亚茹[3] 白广龙[4] 

机构地区：[1]齐齐哈尔医学院,齐齐哈尔161006 [2]华中科技大学生命科学与技术学院,武汉430074 [3]齐齐哈尔医学院第一附属医院遗传室,161042 [4]中国人民解放军第203医院神经科,161000

出　　处：《中国优生与遗传杂志》2012年第4期32-35,41,共5页Chinese Journal of Birth Health & Heredity

基　　金：黑龙江省卫生厅项目(2002020);黑龙江省教育厅科学技术研究项目(10531171)

摘　　要：目的探讨一个遗传性脊髓小脑型共济失调(SCA)大家系的遗传特点和基因突变分析。方法对一个遗传性脊髓小脑型共济失调(SCA)大家系进行家系调查,绘制系谱图,抽取家系成员外周血,采用聚合酶链反应和毛细管电泳对致病基因进行分析检测。结果该家系的遗传性脊髓小脑型共济失调(SCA)为常染色体显性遗传,6代45人中有15人为SCA患者,4人为携带致病基因的无症状患者。患者ATX3基因的CAG三核苷酸重复65-73次。结论该家系为常染色体显性遗传的SCA3型(SCA/MJD),患者基因突变检测分析显示异常扩增的CAG突变数与发病年龄呈明显的负相关。基因突变检测在疾病诊断和早期发现无症状患者方面有重要作用,从遗传生殖角度阻断该病的遗传有重要意义。Objective：To report the genetic characterization of a large Chinese kindred with hereditary spinocerebellar ataxia and to investigate the genic mutation.Methods：To investigale the a large Chinese kindred with hereditary spinocerebellar ataxia.Draw up the pedigree map.DNA extracted from peripheral blood was amplified by PCR and capillary electrophoresis to three exons of hereditary spinocerebellar ataxia gene 24 members.PCR products were directly sequened.Results：There were 45 members in the sex generations of the hereditary spinocerebellar ataxia Kindred.Among them 15 members were patients with diagnostically proven hereditary spinocerebellar ataxia,4 members carry the abnormal gene,but not emerge clinical symptom.Patients wihe the CAG repeat expanded to 65 to 73 repeats in the ATX3.Conclusion：The large Chinese kindred with hereditary spinocerebellar ataxia was the frequency of SCA/JDM for autosomal dominant inheritance.Analysis of the mutation in family showed a strong negative correlation between the size of the expanded CAG repeat and the age of disease onset.The genetic testing plays an important role in early detection of asymptomatic patients,in the diagnosis of SCA and the clinical screening for members in the SCA families.It is important to prevent the transmission of SCA disease to the offspring in the kindred.

关 键 词：遗传性脊髓小脑型共济失调 基因检测 三核苷酸重复 

分 类 号：R744.7[医药卫生—神经病学与精神病学]