D21S1409和D21S11基因座在唐氏综合征诊断中的应用

目的 :研究人类短串联重复序列D2 1S14 0 9和D2 1S11在唐氏综合征基因诊断中的应用。方法 :采集河南无血缘关系汉族个体血样 ,应用Chelex法提取DNA ,聚合酶链式反应扩增 ,非变性聚丙烯酰胺凝胶电泳分型 ;与常规细胞遗传学外周血、绒毛、羊水细胞分裂中期染色体细胞培养分析比较。结果 :得到D2 1S14 0 9和D2 1S11在河南汉族群体中的基因频率 ,分别有 6、11个等位基因 ,12、3 5个基因型 ,杂合度为 0 65、0 81,个体识别率为 0 81、0 94,非父排除率为 0 3 7、0 94。在 12例怀疑为唐氏综合征的患儿中 11例D2 1S14 0 9和D2 1S11诊断与细胞遗传学染色体分析一致 (11/12 ) ,另 1例染色体核型正常而基因诊断为唐氏综合征 ;另 1例绒毛和 1例羊水产前诊断与细胞遗传学染色体分析一致。结论 :在河南汉族人群中D2 1S14 0 9和D2 1S11多态性较好 ,在唐氏综合征基因诊断中有重要意义

The application of D21S1409 and D21S11 STR loci in the Down's Syndrome gene diagnosis

Objective: To investigate the application of D21S1409 and D21S11 short tandem repeats (STR) loci in Down's syndrome.Methods: DNA was extracted with phenol chlorlform from EDTA blood samples of the unrelated individuals in Henan province and amplified with PCR technique.The PCR product was analyzed with the undenatured PAGE vertical electrophoresis and silver stain.We identified by the method of peripheral blood,villrus and aminiotic fluid cell chromosome karyotype.Results: The authors get the frequencies of the loci.The heterozygosities are 0 65,0 81;the discrimination powers are 0.81,0.94.The total accuracy rate of the two loci gene diagnosis is 14/15, another case which is normal chromosome karyotype is considered a patient.Conclusion: The heterozygosities of the two loci are high,it suggest that the loci are available in Down's syndrome gene diagnosis.