强直性肌营养不良的不同组织基因中CTG重复数比较研究

Comparison of CTG trinucleotide repeat numbers in blood and muscle tissues of myotonic dystrophy

目的观察并比较6例强直性肌营养不良(DM)临床确诊或可疑的个体不同组织(血及肌肉)中强直性肌营养不良蛋白激酶(MTPK)基因中CTG三核苷酸(C-胞嘧啶,T-胸腺嘧啶,G-鸟嘌呤)重复次数,寻找最能代表DM动态突变的组织。方法用长模板扩增TMPCR法检测血及肌肉19q13.2-3位点上MTPK基因3’端非翻译区上CTG三核苷酸重复次数。结果5例临床确诊DM患者,其中4例血样本中CTG重复次数明显扩增,3例肌肉样本中CTG重复次数也异常扩增,1例临床可疑DM个体血及肌肉样本中CTG重复次数均明显扩增。结论白细胞核中提取DNA检测CTG三核苷酸重复拷贝次数也很敏感,可反映DM动态突变的变化,并且取样方便,易推广。

Objective To observe and compare CTG trinucleotide repeat numbers ,in the 3'-untranslated region of the myotonin protein kinase(MTPK)gene in blood and muscle tissues of five patients and a doubted individual with myotonic dystrophy(DM)to find which tissue is best reflected dynamic mutation of DM.Method In five patients and a doubted individual with DM,CTG trinucleotide repeat numbers located in the 3'untranslated region of MTPK on chromosome 19q13.2-3 were analyzed by using Long Expand TM Template PCR system.Result CTG repeat numbers were expanded in four of five patients'blood samples and three of five patients' muscle samples,and in one equivocal indivedual with DM,copies of CTG trinucleotide of blood and muscle tissues were expanded.Conclusion Copies of CTG trinucleotide analysed from peripheral blood white cells is also sensitive and exact,which may reflect dynamic mutation of DM.Analysis of CTG repeat numbers from blood is available.