Percesepe Antonio, Ferrari Maurizio, Coviello Domenico, Zanussi Monica, Castagni Marina, Neri Isabella, Travi Maurizio, Forabosco Antonino, Tedeschi Silvana
Unità di Genetica Medica, Università di Modena, Italy.
Prenat Diagn. 2005 Nov;25(11):1011-4. doi: 10.1002/pd.1238.
To report a multi-technical approach to Duchenne muscular dystrophy (DMD) mutation testing through carrier analysis, in the prenatal diagnosis of a male foetus without a known mutation segregating in the family and with inconclusive results of linkage analysis.
Haplotype analysis with the DMD region markers for assigning the carrier status of the mother and for prenatal diagnosis of foetal DNA; semiquantitative multiplex analysis of maternal and foetal DNA for the promoter and for 34 exons of the DMD gene; sequencing analysis of the maternal and foetal DNA for confirmation of the results.
Because of an intragenic recombination of the DMD gene in foetal DNA, haplotype analysis gave inconclusive results. Semiquantitative PCR analysis displayed a pattern compatible with a heterozygous exon 60 mutation in the mother's DNA, while foetal DNA showed a normal migration pattern. Sequencing analysis confirmed the presence of a novel 7 base-pair deletion in exon 60 of the DMD gene in the mother and excluded the deletion in the foetus.
Semiquantitative PCR results allowed the DMD mutation detection in the mother and the exclusion in the foetus, showing its crucial importance in prenatal diagnosis in those cases where linkage analysis is not conclusive.
报告一种通过携带者分析对杜氏肌营养不良症（DMD）进行突变检测的多技术方法，用于产前诊断一个家系中无已知突变分离且连锁分析结果不确定的男性胎儿。
使用DMD区域标记进行单倍型分析，以确定母亲的携带者状态并对胎儿DNA进行产前诊断；对母亲和胎儿DNA进行DMD基因启动子及34个外显子的半定量多重分析；对母亲和胎儿DNA进行测序分析以确认结果。
由于胎儿DNA中DMD基因发生基因内重组，单倍型分析结果不确定。半定量PCR分析显示母亲DNA中的模式与外显子60杂合突变相符，而胎儿DNA显示正常迁移模式。测序分析证实母亲的DMD基因外显子60存在一个新的7碱基对缺失，并排除了胎儿中的该缺失。
半定量PCR结果能够检测出母亲的DMD突变并排除胎儿中的突变，表明在连锁分析不确定的情况下，其在产前诊断中至关重要。
