21三体综合征的诊断与干预研究

Diagnosis and intervention of Down syndrome

目的在细胞、细胞分子和分子水平对21三体综合征(Downsyndrome,DS)进行诊断和干预。方法采用染色体显带、荧光原位杂交(FISH)、多聚酶链反应(PCR)技术,从外周血淋巴细胞、羊水细胞进行DS的诊断、产前诊断和干预。结果在遗传咨询确诊的446例患者中,21三体型、嵌合型、易位型分别占85.43%、6.05%、8.52%。对252例适应症对象进行改良羊水细胞培养产前诊断,取得满意的成功率,并检出DS胎儿3例。10例DS患儿外周血FISH分析,含3个杂交点细胞占90%,含2个杂交点者为10%。20例DS患儿外周血PCR分析,19例(占95%)在3个位点显示三条带。FISH和PCR的阳性结果与细胞遗传学的检测相一致。结论开展以传统细胞遗传学诊断与产前诊断,结合FISH和PCR技术共用,可最大限度地检出DS。

Objective To explore the diagnosis,prenatal diagnosis and early intervention of trisomy 21 syndrome(Down syndrome,DS) at cellular,cell-molecular and molecular levels. Methods The cultured blood lymphocytes and cultured amniotic cells collected from 446 cases who had received genetic counseling and had confirmed the diagnosis of DS were detected by using techniques including chromosome banding,fluorescence in situ hybridization FISH and PCR.Results Among 446 cases,85.43% were trisomy,6.05% were mosaic and 8.52% were translocation.As a technique of prenatal diagnosis,modified amniotic cell culture was successfully undertaken in 252 patients,3 cases of them were identified with DS.The characteristic cells of peripheral blood in 10 cases with DS were analyzed using FISH technique.It was found that 90% of all characteristic cells contained 3 hybridization points and the rest contained 2 hybridization points.Furthermore,the peripheral blood in 20 cases with DS was analyzed using PCR technique.Three bands located at 3 sites were observed in 19 cases that accounted for 95%.Conclusions The results of FISH and PCR were consistent with that of cytogenetics.It is suggested that a combination of prenatal diagnosis and cytogenetics with FISH and PCR could be reliably used for the diagnosis of DS.