CAJ | 학술논문

目的探讨PCR短串联重复(PCR-short tandem repeat,PCR-STR)法快速产前筛查唐氏综合征(Down syndrome,DS)的应用价值及7个STR位点多态性分布特点.方法选择21号染色体核心区域(21q22.1-21q22.2)及其附近的7个STR位点(D21S11、D21S1411、D21S1412、D21S1413、D21S1414、D21S1432、D21S2039),应用PCR-STR扩增对978例高危孕妇羊水样本和82例疑似DS患者外周血样本进行基因诊断筛查检测,并与细胞培养染色体核型分析结果比较.结果 (1)978例羊水和82例外周血样本PCR-STR检测全部成功,7个STR位点多态信息联合分析,以检出2个位点面积比或强度为1∶1∶1三条带；或1个位点1∶1∶1三条带,同时有2个位点面积比或强度为1∶2或2∶1两条带为DS基因诊断标准,共检出DS阳性40例,其中羊水14例阳性,外周血26例阳性.(2)羊水细胞培养染色体核型分析成功961例(98.3％),17例培养失败(1.7％),检出异常染色体核型44例(4.6％),其中14例为DS核型,包括12例标准DS核型,1例易位DS核型,1例嵌合DS核型.17例培养失败羊水经脐带血染色体分析证实均为正常核型.(3)82例可疑DS患者外周血培养全部成功,检出异常染色体核型30例(36.6％),其中26例为DS核型,包括22例标准DS核型,4例易位DS核型；其它异常核型4例.(4)PCR-STR法对7个STR位点联合分析,单例样本可检出1～4个位点为1∶1∶1三条带,或可见2～4个位点为面积比率或强度比为2∶1或1∶2的两条带.羊水和外周血样本DS基因诊断结果与细胞培养染色体核型分析诊断结果完全一致,PCR-STR法快速产前基因诊断DS筛查的灵敏度为100％,未发现假阳性和假阴性结果.(5)7个STR位点杂合率在0.624～0.812,D21S2039和D21S1412位点杂合度最高(＞0.80),D21S1411和D21S1432位点杂合度较低(＜0.70).D21S11和D21S2039位点检出1∶1∶1三条带比率最高(≥40％),而D21S1411、D21S1432、D21S1413位点检出单一条带(纯合率)比率最高(≥30％).结论 PCR-STR法是产前诊断DS的一种快速、有效的筛查方法,7个STR位点联合分析,提供的诊断信息量大,结果准确、可靠. 目的探討PCR短串聯重複(PCR-short tandem repeat,PCR-STR)法快速產前篩查唐氏綜閤徵(Down syndrome,DS)的應用價值及7箇STR位點多態性分佈特點.方法選擇21號染色體覈心區域(21q22.1-21q22.2)及其附近的7箇STR位點(D21S11、D21S1411、D21S1412、D21S1413、D21S1414、D21S1432、D21S2039),應用PCR-STR擴增對978例高危孕婦羊水樣本和82例疑似DS患者外週血樣本進行基因診斷篩查檢測,併與細胞培養染色體覈型分析結果比較.結果 (1)978例羊水和82例外週血樣本PCR-STR檢測全部成功,7箇STR位點多態信息聯閤分析,以檢齣2箇位點麵積比或彊度為1∶1∶1三條帶；或1箇位點1∶1∶1三條帶,同時有2箇位點麵積比或彊度為1∶2或2∶1兩條帶為DS基因診斷標準,共檢齣DS暘性40例,其中羊水14例暘性,外週血26例暘性.(2)羊水細胞培養染色體覈型分析成功961例(98.3％),17例培養失敗(1.7％),檢齣異常染色體覈型44例(4.6％),其中14例為DS覈型,包括12例標準DS覈型,1例易位DS覈型,1例嵌閤DS覈型.17例培養失敗羊水經臍帶血染色體分析證實均為正常覈型.(3)82例可疑DS患者外週血培養全部成功,檢齣異常染色體覈型30例(36.6％),其中26例為DS覈型,包括22例標準DS覈型,4例易位DS覈型；其它異常覈型4例.(4)PCR-STR法對7箇STR位點聯閤分析,單例樣本可檢齣1～4箇位點為1∶1∶1三條帶,或可見2～4箇位點為麵積比率或彊度比為2∶1或1∶2的兩條帶.羊水和外週血樣本DS基因診斷結果與細胞培養染色體覈型分析診斷結果完全一緻,PCR-STR法快速產前基因診斷DS篩查的靈敏度為100％,未髮現假暘性和假陰性結果.(5)7箇STR位點雜閤率在0.624～0.812,D21S2039和D21S1412位點雜閤度最高(＞0.80),D21S1411和D21S1432位點雜閤度較低(＜0.70).D21S11和D21S2039位點檢齣1∶1∶1三條帶比率最高(≥40％),而D21S1411、D21S1432、D21S1413位點檢齣單一條帶(純閤率)比率最高(≥30％).結論 PCR-STR法是產前診斷DS的一種快速、有效的篩查方法,7箇STR位點聯閤分析,提供的診斷信息量大,結果準確、可靠.
목적 탐토PCR단천련중복(PCR-short tandem repeat,PCR-STR)법쾌속산전사사당씨종합정(Down syndrome,DS)적응용개치급7개STR위점다태성분포특점.방법 선택21호염색체핵심구역(21q22.1-21q22.2)급기부근적7개STR위점(D21S11、D21S1411、D21S1412、D21S1413、D21S1414、D21S1432、D21S2039),응용PCR-STR확증대978례고위잉부양수양본화82례의사DS환자외주혈양본진행기인진단사사검측,병여세포배양염색체핵형분석결과비교.결과 (1)978례양수화82예외주혈양본PCR-STR검측전부성공,7개STR위점다태신식연합분석,이검출2개위점면적비혹강도위1∶1∶1삼조대；혹1개위점1∶1∶1삼조대,동시유2개위점면적비혹강도위1∶2혹2∶1량조대위DS기인진단표준,공검출DS양성40례,기중양수14례양성,외주혈26례양성.(2)양수세포배양염색체핵형분석성공961례(98.3％),17례배양실패(1.7％),검출이상염색체핵형44례(4.6％),기중14례위DS핵형,포괄12례표준DS핵형,1례역위DS핵형,1례감합DS핵형.17례배양실패양수경제대혈염색체분석증실균위정상핵형.(3)82례가의DS환자외주혈배양전부성공,검출이상염색체핵형30례(36.6％),기중26례위DS핵형,포괄22례표준DS핵형,4례역위DS핵형；기타이상핵형4례.(4)PCR-STR법대7개STR위점연합분석,단례양본가검출1～4개위점위1∶1∶1삼조대,혹가견2～4개위점위면적비솔혹강도비위2∶1혹1∶2적량조대.양수화외주혈양본DS기인진단결과여세포배양염색체핵형분석진단결과완전일치,PCR-STR법쾌속산전기인진단DS사사적령민도위100％,미발현가양성화가음성결과.(5)7개STR위점잡합솔재0.624～0.812,D21S2039화D21S1412위점잡합도최고(＞0.80),D21S1411화D21S1432위점잡합도교저(＜0.70).D21S11화D21S2039위점검출1∶1∶1삼조대비솔최고(≥40％),이D21S1411、D21S1432、D21S1413위점검출단일조대(순합솔)비솔최고(≥30％).결론 PCR-STR법시산전진단DS적일충쾌속、유효적사사방법,7개STR위점연합분석,제공적진단신식량대,결과준학、가고.
Objective To assess the practicality of rapid prenatal screening for Down syndrome (DS) by polymerase chain reaction-short tandem repeat (PCR-STR) method,and to determine the genotypes of 7 STR loci in ethnic Chinese Han from Weifang region.Methods Seven STR markers (D21S11,D21S1411,D21S1412,D21S1413,D21S1414,D21S1432 and D21S2039) from chromosome 21q22.1-22.2 region were selected.Amniotic samples from 978 high-risk pregnancies and peripheral blood samples from 82 patients suspected with DS were tested with PCR-STR.And the results were verified with G-banding analysis.Results (1) All of the 1 0 6 0 samples were successfully tested by PCR-STR.For normal individuals,the patterns obtained by PCR-STR were two bands with 1 ∶ 1 area ratio or a single band.For DS cases,by contrast,the patterns revealed either three bands with area ratio of 1 ∶ 1 ∶ 1 for two STR loci,or three bands with area ratio of 1 ∶ 1 ∶ 1 for one STR loci and two bands with 2 ∶ 1 or 1 ∶ 2 area ratio for two STR loci.Based on analysis of the 7 STR markers,14 amniotic fluid samples and 26 peripheral blood samples were regarded as DS positive.(2) For the 978 amniotic fluid samples,cytogenetic analysis was successful in 961 (98.3％),among which 44 had an abnormal karyotype.These included 14 trisomy 21 (12 standard type,1 mosaicism and 1 translocation).17 cases which failed amniocytic culture were normal upon fetal blood karyotyping.(3) Cytogenetic analysis was successful in all of the 82 peripheral blood samples,and has identified 30 (36.6％) abnormal karyotypes,among which 26 were trisomy 21 (including 4 with translocation form).(4) For DS positive cases,STR 1-4 showed three bands with area ratio of 1 ∶ 1 ∶ 1,or there were 2-4 loci with two bands with an area ratio of 2 ∶ 1 or 1 ∶ 2.All of the DS cases detected by PCRSTR were confirmed by karyotyping.(5) All of the 7 selected loci were informative,with their degrees of heterozygosity ranging between 0.624 and 0.812.D21S2039 and D21S1412 had the highest heterozygosities (＞0.80),D21S1411 and D21S1432 had the lowest (＜0.70).D21S11 and D21S2039 showed the highest rate (＞40％) of three bands with area ratio 1 ∶ 1 ∶ 1.However,D21S1411,D21S1432 and D21S1413 markers had the highest rate of homozygosity (≥ 30％).Conclusion PCR-STR assay may provide an effective alternative for rapid prenatal DS screening.The 7 selected STR markers are highly informative.The result has featured good accuracy and reliability.