脊髓小脑性共济失调的症状前诊断研究

目的:探讨脊髓小脑性共济失调的症状前患者分子遗传学诊断及其面临的有关问题。方法:对临床诊断为脊髓小脑性共济失调(SCA)患者进行基因诊断的同时根据申请者要求检测其家系“健康”个体,采用聚合酶链反应(PCR)对三核苷酸重复(TNR)片段进行扩增,聚丙烯酰胺凝胶电泳并计算其长度,推算正常和异常扩增等位基因内TNR重复拷贝数。结果:多数家系无症状患者均要求进行致病基因突变检测。通过基因检测诊断出6例SCA3、2例SCA1、2例SCA12症状前患者。结论:分子遗传学检测可作出可靠的症状前诊断。进行遗传咨询应考虑医学、伦理、法律及社会诸多问题。

A study on presymptomatic testing for spinocerebellar ataxias

Objective: To study presymptomatic testing for spinocerebellar ataxias(SCA) and issues related to it. Methods;Molecular genetic diagnosis was made on healthy individuals from the SCA families according to the applicants when that was done on the patients. The trinucleotide repeats were detected by polymerase chain reaction (PCR) , denaturing polyacrylamide gel elec-trophoresis and silver staining technique. The repeat numbers were caculated. Results; The majority of asymptomatic individuals form the SCA families apply for presymptomatic testing. Six SCA3 ,two SCA1 ,two SCA12 presymptomatic patients were found. Conclusions; Presymptomatic testing can be made by molecular genetic detection. Medical, ethical, legal and social issues should be taken into consideration in genetic counselling.