应用多重连接依赖式探针扩增技术快速高通量诊断胎儿染色体非整倍体异常

目的 评价多重连接依赖式探针扩增技术(multiplex ligation-dependent probe amplification,MLPA)在染色体非整倍体诊断中的应用价值,为我国羊水染色体诊断提供一种快速、特异、高通量的分子诊断手段.方法 应用MLPA技术检测了500份羊水标本,所有标本均进行荧光原位杂交(fluorescence in situ hybridization,FISH)技术检测和常规染色体核型分析,应用RH-MLPA-v511数据分析软件获得MLPA结果,比较MLPA技术与FISH和染色体核型分析结果的准确性,总结MLPA技术临床应用过程中的关键要点.结果 在500份羊水标本中,MLPA检测成功率97%.3个工作日完成结果的为92%,需重复检测的为5%,失败为3%.对染色体非整倍体异常检测敏感性和准确性100%.证实38例非整倍体病例探针信号比值＞正常二倍体4s,2例疑似三体结果＞2s.分析了21号染色体8条探针的杂交效率,21三体患者8条探针中平均4条探针比值＞1.3.结论 MLPA技术具有快速、特异、敏感、高通量、成本低等特点,可用于产前染色体非整倍体数目的快速检测,是传统染色体培养方法的补充,临床应用价值较高.

Abstract：

Objective To assess the diagnostic value of multiplex ligation-dependent probe amplification (MLPA) for detection of common chromosome aneuploidy in amniotic fluid (AF) cells in order to obtain an accurate, rapid, cost-effective and high-throughput method in routine prenatal clinical practice.Methods The MLPA test was performed on 500 AF samples by using kit P095 and the results were obtained by using analysis software RH-MLPA-v511. The results were compared with that from fluorescence in situ hybridization (FISH) and traditional karyotyping (TK). The technical critical issues were analyzed in routine diagnostic application. Results The absolute specificity and sensitivity of the MLPA test to detect the aneuploidy were 100%. For the 500 AF samples, the success rate of the MLPA tests was 97%. Among them 92% were finished within three working days and 5% required more days for repeating. The test failure rate was 3%. The results confirmed that for the 38 detectable aneuploid samples,the probe reliability weighted mean ratio values were more than 4SD compared to normal diploids and the 2 suspected trisomy samples were more than 2SD. In this study, authors analyzed hybridization efficiencies of 8 probes for chromosome 21, and the presence of a trisomy was considered if at least 4 of the 8 probes gave probe ratio of ＞1.3. Conclusion The data suggested that MLPA is a rapid, simple and reliable method for large scale testing for aneuploidy of chromosomes 13, 18, 21, X, or Y in AF. The MLPA technology is complementary to AF culture and valuable for prenatal diagnosis.

Rapid and high-throughput multiplex ligation-dependent probe amplification for diagnosis of chromosome aneuploidy

Objective To assess the diagnostic value of multiplex ligation-dependent probe amplification (MLPA) for detection of common chromosome aneuploidy in amniotic fluid (AF) cells in order to obtain an accurate, rapid, cost-effective and high-throughput method in routine prenatal clinical practice.Methods The MLPA test was performed on 500 AF samples by using kit P095 and the results were obtained by using analysis software RH-MLPA-v511. The results were compared with that from fluorescence in situ hybridization (FISH) and traditional karyotyping (TK). The technical critical issues were analyzed in routine diagnostic application. Results The absolute specificity and sensitivity of the MLPA test to detect the aneuploidy were 100%. For the 500 AF samples, the success rate of the MLPA tests was 97%. Among them 92% were finished within three working days and 5% required more days for repeating. The test failure rate was 3%. The results confirmed that for the 38 detectable aneuploid samples,the probe reliability weighted mean ratio values were more than 4SD compared to normal diploids and the 2 suspected trisomy samples were more than 2SD. In this study, authors analyzed hybridization efficiencies of 8 probes for chromosome 21, and the presence of a trisomy was considered if at least 4 of the 8 probes gave probe ratio of ＞1.3. Conclusion The data suggested that MLPA is a rapid, simple and reliable method for large scale testing for aneuploidy of chromosomes 13, 18, 21, X, or Y in AF. The MLPA technology is complementary to AF culture and valuable for prenatal diagnosis.