摘要
OBJECTIVE: To observe trinucleotide repeat number, (CTG)n in the 3'-untranslated region of the myotonic protein kinase (MTPK) gene in a clinically suspected woman with myotonic dystrophy (DM) family history and her abortus, in order to confirm the necessity of exerting antenatal examination in patients or suspected individuals with DM family history. METHODS: Long Expand Template polymerase chain reaction (PCR) system was used to analyze CTG trinucleotide repeat numbers located in the 3' untranslated region of MTPK on chromosome 19q13.2-3 in both peripheral white cells and muscles of the suspected mother and the other two DM patients in the family. The tissues of her abortus and blood of a health woman were detected, too. RESULTS: CTG repeats in both peripheral white cells and muscles of the suspected mother and the tissue of abortus were higher than normal range of CTG repeat number. There is no significant difference between blood and muscle samples. High CTG repeats were detected in blood and muscles of the typical DM members in the family, but in the blood sample of control, CTG repeats is normal. CONCLUSION: CTG trinucleotide analyses and antenatal examination should be done in pregnant with a DM family history, in order to reduce the birth rate of DM offspring.
目的通过测定一强直性肌营养不良(myotonic dystrophy,DM)家系中一临床可疑女性DM个体与其流产胎儿的肌强直蛋白激酶(Myotonic Protein kinase,MTPK)基因中CTG三核苷酸(C-胞嘧啶,T-胸腺嘧啶,G-鸟嘌呤)重复拷贝数,证实DM家族中的患者及可疑个体作产前检查的必要性.方法用长模板扩展TMPCR法检测孕母及家系中其它两个典型患者的血,肌肉及胎儿组织19q13.2-3位点上肌强直蛋白激酶(MTPK)3′端基因非翻译区上CTG三核苷酸重复拷贝数,并与一正常妇女血标本做对照. 结果该可疑个体外周血白细胞、肌肉及胎儿组织中MTPK基因CTG三核苷酸重复拷贝数均高于正常,并且血液及肌肉DNA中的CTG三核苷酸重复拷贝数无明显差别.家系中典型患者的血、肌肉DNA中的CTG三核苷酸重复拷贝数也有升高,但健康对照的CTG三核苷酸重复拷贝数正常.结论具有DM家族史的孕妇应早期进行分子诊断与产前检查,以杜绝患儿出世.
