多重链接探针扩增技术在染色体非整倍体畸变诊断中的应用

Application of multiplex ligation-dependent probe amplification to diagnosis and prenatal diagnosis of common aneuploidies

目的 探讨多重连接探针扩增（multiplexligation-dependent probe amplification,MLPA）技术在13、18、21、X、Y染色体非整倍体畸变诊断中的应用价值.方法 收集本院经染色体核型分析确诊包括有上述5种染色体数目异常及正常的样本共44份,其中外周血30份、胎儿脐带血10份、羊水4份,提取标本DNA,采用MLPA技术对样本染色体数目进行分析,并与染色体核型分析结果进行比对.结果 42例样本检测结果与染色体核型分析结果一致,1例染色体核型分析未能作出判断的标记染色体片段被识别为Y染色体片段,1例21-三体嵌合体未能做出明确判断,临床检出率97.7%（43/44）.结论 MLPA技术通过单管反应同时检测40多个不同靶基因序列的拷贝数,具有高通量、特异、便捷及成本较低等特点,可应用于常见染色体非整倍体畸变的临床诊断和产前诊断.

Objective To investigate the application value of the multiplex ligation-dependent probe amplification （MLPA） technique in diagnosis and prenatal diagnosis of chromosomes 13, 18, 21, X and Yaneuploidy. Methods Forty-four cases including 30 peripheral blood samples, 10 fetal cord blood samples,and 4 amniotic fluid samples were collected in this study. DNA was isolated from the samples and detected by MLPA, followed by analyzing in ABI310 Genetic Analyzer. Analysis of copy number changes for chromosomes 13, 18, 21, X and Y was carried out with RH-MLPA-analysis software. The routine karyotype analyses were also done for all the samples. Results Of 44 samples, the results of 42 by MLPA method was consistent with that by chromosome karyotyping. Only one case with trisomy 21 chimerism was failed to reach conclusion. In addition, one case of mark chromosome segment was identified as Ychromosome segment by MLPA, while karyotyping failed to make judgment. The accurate rate of MLPA was 97. 7% （43/44）. Conclusion The MLPA technique can simultaneously detect dozens of different target sequences and their copy number changes in a single reaction. It showed high specificity, good reproducibility, was fast and high-throughput. The MLPA technique can be applied to diagnosis and prenatal diagnosis of the common chromosomal aneuploidy.