应用DNA-STR基因座分型技术快速诊断唐氏综合征

Rapid diagnosis of Down's syndrome by DNA-STR loci classification technology

目的:探讨DNA-STR基因座分型技术对快速诊断唐氏综合征的应用价值。方法:选择两个位于21号染色体上STR基因座(D21S11和Penta D),采用PCR扩增技术,对60例样本(包括外周血20例,脐带血5例,羊水35例)进行STR基因座复合扩增,毛细管电泳分型,根据STR基因座分型的结果与核型结果进行比较。结果:48例正常核型的样本中D21S11和Penta D基因座出现纯合子或荧光强度为1∶1的杂合子基因型,12例21三体核型样本的基因座出现荧光强度为1∶1∶1的三等位基因或者荧光强度为2∶1的不均一杂合子基因型。STR基因座分型结果与核型检测结果相符。结论:应用DNASTR基因座分型技术能够快速检测21号染色体的非整倍型,对快速诊断唐氏综合征具有重大应用前景。

Objective： To explore the application value of DNA-STR loci classification technology in rapid diagnosis of Down＇s syndrome. Methods： Two STR loci（ D21S11 and Penta D） in chromosome 21 were selected,STR loci multiplex amplification and capillary electrophoresis classification were performed among 60 specimens（ including 20 specimens of peripheral blood,5 specimens of umbilical cord blood,and 35 specimens of amniotic fluid） by PCR amplification technique; the results were compared with karyotyping results. Results：Homozygote genotype or heterozygous genotype with fluorescence intensity of 1 ∶ 1 were found in D21S11 and Penta D loci among 48 specimens with normal karyotypes; triallele with fluorescence intensity of 1 ∶ 1 ∶ 1 or heterozygous genotype with fluorescence intensity of 2 ∶ 1were found in loci of 12 patients with trisomy 21. STR loci classification results were coincidence with Karyotyping results. Conclusion：DNA-STR loci classification technology can quickly detect aneuploid chromosome 21,which has an important application prospect for rapid diagnosis of Down＇s syndrome.