多重荧光定量PCR技术快速诊断21三体及18三体方法的建立及临床应用

利用收集的20例21三体、3例18三体DNA样本及40例正常人DNA样本,选择多对21、18号染色体短串联重复序列分子标记,建立多重荧光定量PCR检测技术用于21三体、18三体的快速产前诊断;利用建立的方法对165例产前诊断病例及4例消化道畸形新生儿进行检测,并与核型分析结果相比较。169例病例中共诊断21三体4例,18三体1例,所有病例均在1～3d得到结果,无漏诊和误诊,并利用建立的多重荧光定量PCR技术为5例核型分析失败的病例提供了明确的产前诊断。对于同期B超检查胎儿结构异常的22例胎儿,则采用传统的核型分析,检出1例(45,X),1例(47,XXY)。结果表明建立的多重荧光定量PCR技术可快速、准确地诊断21三体和18三体,减轻核型分析需时过长给孕妇带来的焦虑,可用于血清学筛查21三体、18三体高风险者及高龄孕妇,也适用于对其他遗传性疾病如遗传性耳聋进行产前诊断时并行检测以排除21三体和18三体。多重荧光定量PCR技术结合传统核型分析可更好的满足产前诊断的临床需求。

Development of multiple quantitative fluorescent PCR for rapid diagnosis of common aneuploidy and it's clinical application

In this study we have established a technique of multiple quantitative fluorescent polymerase chain reaction (QF-PCR) for prenatal diagnosis of common chromosomal abnormality using multiple short tandem repeat markers (STR-marker) on chromosomes 21 and 18 with the DNA samples from 20 cases of Down's syndrome, 3 cases of trisomy 18 and 40 cases normal controls. The technique established was applied in prenatal diagnosis in 165 clinical cases and 4 cases of newborn infants with digestive tract obstruction. The result this technique was compared with the results of karyotyping. Four cases of trisomy 21 and 1 case of trisomy 18 were identified among 169 samples, which was completely concordant with the results of karyotyping. All clinical samples were diagnosed in 1-3 days without misdiagnosis and missed diagnosis. Five cases were diagnosed by QF-PCR only due to the failure of karyotyping. Twenty-two cases of fetuses with structure malformation indicated by B-ultrasonography were subjected to karyotyping. One case of 45, X and 1 case of 47, XXY were identified. In conclusion, QF-PCR technique is rapid and accurate for the detection of trisomy 21 and trisomy 18. It is suitable for prenatal diagnosis of common chromosomal abnormality for pregnant women with advanced ages who were identified as having a high risk by serum screening. QF-PCR technique combined with karyotyping can provide better service for clinical demanding of prenatal diagnosis.