用荧光原位杂交技术产前诊断唐氏综合征

Application of fluorescence in situ hybridization to prenatal diagnos is of Down syndrome

目的用荧光原位杂交技术(fluorescenceinsituhybridization,FISH)快速产前诊断唐氏综合征。方法采集23名孕妇14～24周的羊水标本,应用荧光标记的针对21号染色体特殊位点的探针(locusspecificprobe,LSI)及X/Y染色体着丝粒探针(centromericprobe,CEP)对未培养的羊水间期细胞进行FISH;同步进行羊水细胞培养,行常规细胞遗传学染色体核型分析,以核型分析为标准,对FISH技术进行评价。结果23份标本发生母血污染2例,培养失败1例,将其余20份羊水标本的FISH杂交结果与其染色体核型分析结果进行了比较。FISH分析羊水间期细胞性染色体数目正常者19例(XX11例、XY8例),与羊水中期细胞染色体核型分析结果一致,有1例羊水间期细胞FISH结果为X/XY,染色体核型分析结果为46,XY,因此,FISH与染色体核型分析结果的符合率为95%(19/20);LSI21探针的FISH结果中21号染色体数目异常者1例,核型分析为典型的21三体,取脐血行G显带染色体核型分析得以验证为47,XY,+21。产前诊断染色体正常者追踪至分娩,新生儿行外周血染色体检查结果皆为正常核型。结论荧光原位杂交技术可用于羊水间期细胞快速产前诊断唐氏综合征。

Objective Fluorescence in situ hybridization (F IS H) was performed with specific probes to make the rapid prenatal diagnosis of Do wn syndrome. Methods FISH was performed respectively with locus -specific probe(LSI) 21 and centromeric probe(CEP) X/Y on the uncultured amniotic fluid samples,and the cultured samples w ere analyzed by traditional cytogenetics to find the concordance rate between FI SH and standard cytogenetics. Results Amniocentesis was perform ed in 23 pregnant women. Two samples were discarded because of contamination by maternal blood; one case of culture failed. A typical trisomy 21 found by FISH w as in accordance with the result of traditional cytogenetics. A case with abnor mal karyotype (X/XY) found by C EPX/Y probe was proved to be normal (46, XY) by cytogenetics. So the concordan ce rate was 95%(19/20). Conclusion FISH is a rapid and relia ble method to detect Down syndrome in uncultured amniotic fluid.