MLPA联合FISH在DMD基因突变产前诊断中的价值探讨

目的:分别采用多重连接探针扩增技术(MLPA)与荧光原位杂交技术(FISH)针对外周血及羊水标本分析杜氏/贝氏肌营养不良(DMD/BMD)患者DMD基因缺失/重复突变的类型。分析在DMD/BMD产前诊断中两者联合应用的诊断价值。方法:对2009年1月-2010年1月在我院行基因诊断的3个DMD/BMD家系共5位先证者及其15位女性亲属采用MLPA进行DMD基因的分析,获得缺失/重复片段范围,再通过BAC克隆制备相应区段的直标型FISH探针,并用X染色体着丝粒探针作为对照。分别采取MLPA和FISH技术对羊水标本进行检测,与分娩后取样的MLPA检测结果进行对照。结果:MLPA与FISH技术检测效果在外周血中完全一致,但3例羊水标本中采用MLPA进行检测有1例无法满足分析要求,1例出现假阳性结果,另1例为真阴性结果,MLPA联合用FISH检测结果均正确。结论:MLPA和FISH检测DMD基因缺失/重复在外周血中都能够获得准确的结果,但对于羊水标本MLPA联合FISH进行检测的准确性更高。

Predictive value of MLPA combined with FISH in prenatal diagnosis of DMD/BMD

AIM: To detect Duchenne muscular dystrophy (DMD) genetic deletion/duplication from the peripheral blood and amniotic fluid in the patients of DMD/Becker muscular dystrophy (BMD) by using multiple ligation probe amplification(MLPA) and fluorescent in situ hybridization(FISH), and to analyze the predictive value of these two techniques in prenatal diagnosis of DMD/BMD. METHODS: Five patients and 15 of their female relatives from 3 DMD/BMD families were selected and MLPA analysis was conducted. Deletions/duplication regions were used as directions for producing FISH probes labeling from BAC clones, with the X chromosomal centromere probe as control. The results of MLPA and FISH in detecting DMD/BMD patients and carriers of the peripheral blood and amniotic fluid were compared. RESULTS: The MLPA and FISH results of peripheral blood were fully accordant. Discordant results were found in 2 out of 3 amniotic fluid samples, where the FISH results were certified correct with the follow up investigations. CONCLUSION: Both MLPA and FISH are correct in detecting DMD deletion/duplication from blood samples, while more accurate results would be given by combination of FISH test.