一家系4代9例脊髓小脑性共济失调临床特征与基因检测分析

目的通过对一家系4代9例脊髓小脑性共济失调(SCA)患者的临床特征和部分患者的基因测序分析,为临床诊断提供依据。方法通过先证者建立家系图谱,收集患者的发病年龄、主要症状、持续时间和死亡患者的年龄,建立该家系患者的临床特征;通过聚合酶链反应(PCR)技术检测先证者和其无症状女儿的SCA1、SCA2、SCA3、SCA6、SCA7、SCA12和齿状核-红核-苍白球-丘脑路易斯核萎缩(DRPLA)的三核苷酸重复序列的数目,确立其遗传类型。结果该家系4代9例患者,第Ⅰ代发病年龄55岁,死亡60岁;第Ⅱ代发病年龄50岁,死亡60岁;第Ⅲ代发病30～47岁,死亡60岁;第Ⅳ代发病20岁。主要症状均为走路不稳和语言含糊不清,从发病到死亡的持续时间1～30年;基因测序表明先证者SCA3相关基因的CAG重复数目20/73,其女儿为15/78;其余SCA1、SCA2、SCA6、SCA7、SCA12、DRPLA基因测序均在正常范围内。确诊为SCA3。结论基因测序可以帮助确诊SCAs和无症状患者。

Clinical characteristics and genetic analysis of 9 cases with spinocerebellar ataxia from 4 generations in one family

Objective To investigate the clinical diagnosis of spinocerebellar ataxia(SCA)by clinical observation and genetic analysis in one parentage,4 generations.Methods Firstly,family investigation and pedigree analysis were performed,and the family charaeteristics were established by observing the age of onset,main complains,symptom duration and age of death.Then,the hereditary subtype was established through scanning the duplicate number of trinucleotide in pathogenic CAG of SCA1,SCA2,SCA3,SCA6,SCA7,SCA12 and DRPLA(Dentatorubral-Pallidoluysian Atrophy,DRPLA) by polymerase chain reaction and direct DNAsequencing in the proband and one of his asymptomatic daughter.Results The age of onset was 55 years in the first generation,50 years in the second generation,30-47years in the third generation and 20 years in the forth generation respectively,gait ataxia and slurred speech were the main symtoms.the duration from onset to death was 1-30 years.The SCA3 duplicate number of CAG was 20/73 in the propositus and 15/78 in his daughter,the other numbers were normal.the diagnosis of SCA3 was established.Conclusion DNA sequencing is useful to diagnose the SCAs and it's Asymptomatic patients.