摘要
目的探讨一种快速、简便、准确检测21三体综合征的基因诊断方法。方法选用位于21号染色体Down′s综合征核心区(21q21-21q22)内及其附近的短串联重复序列(STR)(D21S1432,D21S11,D21S1436,D21S1442,D21S1270,D21S1411,D21S1446),建立STR-PCR快速诊断平台。通过对经染色体核型分析的10例正常胎儿的羊水脱落细胞DNA,及4例判定为21三体综合征胎儿的绒毛组织DNA进行21号染色体STR分析,从而进行方法评价。结果在上述7个STR位点中,10名正常胎儿除在D21S1436位点存在2∶1条带的占5/10,其余位点杂合度(64.29%-92.86%)及相互间的符合率为100%。4例21三体胎儿经6个STR位点联合分析,均被确诊为21三体综合征。结论6个STR位点(D21S1432,D21S11,D21S1442,D21S1270,D21S1411,D21S1446)可作为21三体综合征有价值的遗传标记,可用于对其做出快速、准确的基因诊断。
Objective： To study a molecular method for fast diagnosis of trisomy 21. Methods： Seven short tandem repeat （STR） （D21S1432, D21Sll, D21S1436, D21S1442, D21S1270, D21S1411, D21S1446）of Chromosome 21 were selected, to develop a novel short tandem repeat （STR） - based strategy for fast diagnosis of trisomy 21 in fetal cells. The system is based on seven STRs, all of which were previously known and in the genomic sequence of the long arm of chromosome 21, which in and adhered to Down＇s syndrome core area. To evaluate the muhimarker diagnostic system, the combination of all seven STR markers were applied to DNA from 10 amniotic fluid samples for Chinese fetus with normal karyotype, and from 4 chorionic villus sampling （CVS） form pregnancies complicated with fetal trisomy 21 cases, which were detected by karyotyping. Result： All six markers did not yield any false -positives/ negatives, except D21S1436. And they were confirmed to be moderately polymorphic （64.29% -92. 86% ） by PCR amplification and gel electrophoresis. Conclusion： All six STR markers above （D21S1432, D21Sll, D21S1442, D21S1270, D21S1411, D21S1446） were valuable in detecting trisomy 21, and our new strategy can provide an alternative molecular technique for the rapid detection of aneuploidy.
出处
《中国优生与遗传杂志》
2009年第5期28-31,共4页
Chinese Journal of Birth Health & Heredity
