变性高效液相色谱法产前诊断18三体综合征

Prenatal diagnosis of trisomy 18 by denaturing high-performance liquid chromatography

目的用变性高效液相色谱法(DHPLC)分析1例18三体综合征胎儿的双链DNA,快速产前诊断18三体综合征。方法根据所设计的引物对18号染色体D18S1002、D18S51和D18S499共3个短串联重复序列(STR)位点进行PCR扩增,然后在50℃柱温条件下用DHPLC对PCR扩增产物进行检测和分析。结果健康人D18S51的DHPLC峰形呈现两个高低相同的波峰,18三体综合征胎儿D18S51的DHPLC峰形呈现两个高低不同的波峰,其中一个波峰高度接近为另一个波峰的2倍。健康人D18S1002的DHPLC峰形呈现一个波峰,18三体综合征胎儿D18S1002呈现两个高低不同的波峰,其中一个波峰高度接近为另一个波峰的2倍。健康人D18S499的DHPLC峰形呈现一个波峰,18三体综合征胎儿D18S499呈现两个高低不同的波峰,其中一个波峰高度接近为另一个波峰的2倍。结论健康人染色体核型有两条18号染色体,而18三体综合征患者染色体核型则有3条18号染色体,结合3个STR位点的DHPLC波峰数量及波峰高度,即可对患者做出确切的诊断。该方法灵敏度高、特异性强、简便、快捷等,适合广泛应用于18三体综合征的临床诊断。

Objective Double DNA of trisomy 18in the fetus were detected by denaturing high-performance liquid chromatography（DHPLC）for quick prenatal diagnosis of trisomy 18.Methods To amplify different DNA fragments of short tandem repeat of D18S1002,D18S51and D18S499using corresponding primers.DHPLC was introduced to analyze DNA fragments in the temperature of 50.Results DHPLC elution profile of D18S51of normal control show one peak.However DHPLC elution profile of D18S51 of 18trisomy showed two peaks of different altitude which one′s altitude was twice than another.DHPLC elution profile of D18S1002of normal control show two peaks of same altitude.However DHPLC elution profile of D18S1002of 18trisomy show two peaks of different altitude which one′s altitude was twice than another.DHPLC elution profile of D18S499of normal control show one peak.However DHPLC elution profile of D18S499of 18trisomy show two peaks of different altitude which one′s altitude was twice than another.Conclusion Karyotype of normal control has two chromosome 18,however karyotype of trisomy 18has three chromosome 18.According to magnitude and altitude of DHPLC elution profile,we can diagnose trisomy 18.DHPLC is a sensitive,convenient,automatic and highly-efficient method for diagnosis of trisomy 18and can be widely used in clinic.