中国人DMD基因缺失检测多重PCR新体系的建立

New multiplex-PCR assay for detection of deletions of DMD gene in Chinese DMD patients

目的建立新的适合中国人DMD特征的多重PCR体系，提高缺失突变的检出率。方法对经“一步到位”诊断程序和MLPA分析确定的355例缺失型DMD患者的缺失突变谱进行归纳总结，筛选出缺失高发的外显子区域，挑选代表性外显子，组装成扩增体系，优化多重PCR条件。结果经过对355例缺失型DMD患者的突变谱分析后，总结出两套新的多重PCR体系。第一套检测体系分两组，检测10个外显子（外显子5、8、17、44、45、47、49、50、51和52），可检出92％（326／355）的缺失；第二套检测体系检测另外5个外显子（外显子12、19、35、43和54），可进一步检测到5％（17／355）的缺失。在后续22例DMD患者的检测验证中，所有患者的多重PCR结果均与MLPA结果吻合。结论这两套新体系是在对355例中国缺失型DMD患者的缺失分析的基础上归纳而成，所涉及的DMD病例来源遍布全国，更适合于中国人群DMD患者缺失突变的检测。

Objective To establish a new multiplex-PCR assay to improve the detection rate of mutations in the DMD gene in Chinese patients. Methods A retrospective review of DMD deletion spectrum of 355 DMD patients with deletions all over the gene was performed. All deletions were confirmed by ＂one- step approach＂ diagnostic procedure and MLPA analysis. The exons with high frequency of mutations were identified to constitute the amplification system and the PCR conditions were optimized. Results Two new multiplex-PCR assays were established. Assay one was used to detect 10 exons including exon 5, 8, 17, 44, 45, 47, 49, 50, 51 and 52 of DMD gene, in two PCR sets. The theoretical detection rate would be 92% （326/355）. Assay two was used to detect 5 exons including exon 12, 19, 35, 43 and 54, which could be used to screen additional 5% （17/355） deletion cases. The method was validated in other 22 DMD patients. Multiplex-PCR results were completely identical to the MLPA results in all 22 DMD patients. Conclusions The two muhiplex-PCR assays were established based on the analysis of 355 Chinese DMD patients with gene deletions. It is believed that the new approach would be more applicable for deletion detection on the Chinese DMD patients since the DMD cases involved were from the whole country.