妊娠早期应用荧光原位杂交技术快速诊断唐氏综合征

目的：评价产前应用２１号染色体特异性探针荧光原位杂交技术快速诊断胎儿唐氏综合征的可行性。方法：应用２１号染色体区域特异性探针对３０例未经培养的早孕期绒毛细胞进行原位杂交，并同时行常规细胞遗传学分析以对比诊断。结果：正常染色体核型标本中，只有约１％（０％￣５％）的间期核呈现３个杂交信号，而在２１，三体型标本中，平均８６％（７８％￣９１％）的细胞核呈现３个杂交信号。结论：应用荧光原位杂交技术在妊娠早期     

应用双色荧光原位杂交技术检测一例49,XXXXY性染色体异常

目的:探讨用双色荧光原位杂交技术(dual-color fluorescence in situ hybridization,D-FISH)检测性染色体数目异常的实验方法及其应用价值。方法:以Biotin标记的X染色体α-卫星DNA(pBamX7)探针和以Digoxigenin标记的Y染色体长臂末端重复顺序(pY3.4)探针与经处理的标本同时进行外周血染色体及间期细胞核的原位杂交,分别用Avidin-FITC和Rhodamine-FITC及其Anti-avidin进行信号的检测与放大,DAPI复染。于Olympus AX-70型荧光显微镜下,分别通过WIB、WIG及其WU滤光镜观察杂交信号及其染色体或间期核背景,并统计外周血中期染色体和间期细胞核的杂交信号颗粒数。结果:在显微镜下可见以Biotin标记的pBamX7探针显示4个绿色杂交信号,以Digoxigenin标记的pY3.4探针显示1个红色杂交信号,染色体或细胞质背景经DAPI复染显示兰色;统计350个中期染色体和间期细胞核,X染色体杂交信号阳性率分别为91.43％和92.57％;Y染色体杂交信号阳性率分别为99.5％和99.8％。结论:双色荧光原位杂交技术是检测49,XXXXY性染色体异常以及其他性染色体数目异常患者的一种十分有价值的技术,具有高效、灵敏、可靠等特点,可为临床提供良好的辅助诊断。     

染色体13／21α卫得探针用于产前诊断21三体综合征

目的：探讨应用染色体13／21α卫星探荧光原位杂交（FISH）技术行产前论断21三体综合征的价值。方法：选择10例经产前细胞遗传学检查证实为孕正常胎儿孕妇的羊水细胞（对照组）、3例证实为21三体胎儿孕妇的羊水细胞（观察组）,用13／21α卫星探针对未经培养的羊水细胞间期核进行FISH杂交,结果：两组总杂交率分别为36．7％和38．6％,差异无显著性（P＞0．05）。对照组和观察组含4个杂交信号的核平均丰分比分别为36．5％和3．9％,含5个杂交信号的核平均百分比分别为4．0％和36．1％,差异有极显著性（P＜0．01）,含5个信号的百分比＜36．1％可作为21三体综合征的诊断标准。结论：13／21α卫星探针间期FISH用于未培养的羊不细胞可以快速,准确地在产前诊断21三体综合征。     

染色体13/21α卫星探针用于产前诊断21三体综合征

目的探讨应用染色体13/21α卫星探针荧光原位杂交（FISH）技术行产前诊断21三体综合征的价值。方法选择10例经产前细胞遗传学检查证实为孕正常胎儿孕妇的羊水细胞（对照组）、3例证实为孕21三体胎儿孕妇的羊水细胞（观察组）,用13/21α卫星探针对未经培养的羊水细胞间期核进行FISH杂交。结果两组总杂交率分别为36.7%和38.6%,差异无显著性（P>0.05）。对照组和观察组含4个杂交信号的核平均百分比分别为36.5%和3.9%,含5个杂交信号的核平均百分比分别为4.0%和36.1%,差异有极显著性（P<0.01）,含5个信号的核百分比＜36.1%可作为21三体综合征的诊断标准。结论 13/21α卫星探针间期FISH 用于未培养的羊水细胞可以快速、准确地在产前诊断21三体综合征。     

唐氏综合征的产前诊断分子技术研究进展

唐氏综合征是人类常见的染色体疾病,经典的细胞遗传学方法是诊断唐氏综合征的金标准,但其局限性不适合大规模的产前诊断.随着分子细胞遗传学技术发展,荧光原位杂交技术(FISH)、定量荧光PCR(QF-PCR)、微阵列-比较基因组杂交(Array CGH)、多重连接探针扩增技术(MLPA)、引物原位标记技术(PRINS)等被用于唐氏综合征快速产前诊断,各种方法各有优劣,改进后会大力推进唐氏综合征的产前诊断速度和准确性.     

荧光原位杂交技术快速产前诊断胎儿血细胞非整倍体的价值

目的 探讨荧光原位杂交（FISH）技术在产前诊断脐血细胞非整倍体中的应用价值：方法 2004-06—2005-03，对广州市妇婴医院114例孕18～38W有产前诊断指征的孕妇进行脐血穿刺。采用X／Y染色体着丝粒探针和21q22．13-q22．2特异性探针对脐血细胞进行间期FISH检测，然后在荧光显微镜下观察，用Leica染色体核型自动分析仪QFISH软件进行图像的摄取和处理。同时所有脐血标本进行细胞培养，常规染色体G显带核型分析作为对照。结果 114例脐血标本都有FISH检测结果，107例具有正常核型染色体数目，异常7例，其中4例为唐氏综合征（3例为典型唐氏综合征，1例为嵌舍体），3例为性染色体数目异常。结论 FISH技术用于产前诊断脐血常见染色体数目异常，具有简便、快速、特异性强等优点，能为临床诊断提供依据。     

唐氏综合征的产前诊断分子技术研究进展

唐氏综合征是人类常见的染色体疾病，经典的细胞遗传学方法是诊断唐氏综合征的金标准，但其局限性不适合大规模的产前诊断。随着分子细胞遗传学技术发展，荧光原位杂交技术（FISH）、定量荧光PCR（QF-PCR）、微阵列-比较基因组杂交（Array CGH）、多重连接探针扩增技术（MIJPA）、引物原位标记技术（PRINs）等被用于唐氏综合征快速产前诊断，各种方法各有优劣，改进后会大力推进唐氏综合征的产前诊断速度和准确性。     

双色共变性荧光原位杂交产前诊断胎儿唐氏综合征

目的 探讨双色共变性荧光原位杂交用于非侵入性产前诊断胎儿唐氏综合征的可行性。方法 对11例孕妇外周血中的胎儿有核红细胞进行抗血型糖蛋白磁珠直接标记,再经磁激活细胞分选法富集,以Y和21号染色体专一探针对分离的胎儿有核红细胞行双色共变性荧光原位杂交,预测胎儿21号染色体倍性和性别,并用羊水染色体核型分析结果,验证预测准确性。结果 11例胎儿21号染色体倍性均正常,与羊水染色体核型分析结果相符。其中5例为男性胎儿,男性胎儿有核红细胞数量为9－65个,平均为25个,男性胎儿有核红细胞纯度为1．4％－18．8％;6例为女性胎儿,孕妇外周血中未见男性胎儿有核红细胞;性别预测结果与羊水染色体型分析结果一致。结论 双色共变性荧光原位杂交用于分析胎儿21号染色体倍性及性别,诊断胎儿唐氏综合征准确、可靠。     

荧光原位杂交技术在胚胎植入前性别诊断中的应用

目的 探讨荧光原位杂交技术在人光胚胎植入前性别诊断中的应用价值。方法对２例因友病基因携带者和２例Ｙ染色体异常的患者进行了５个周期的超排卵治疗,胚活检后取单个细胞进行固定,然后用荧光原位杂交技术检测胚胎的性别,最后选择女性胚胎移植入子宫腔。结果 ４例患者５个治疗周期共取卵１１０个,受精率为６８．２％,可供活检的胚胎５５个,活检成功率为８５．５％,活检后继续分裂率为６１．７％,活检细胞固定率为９７．     

改良荧光原位杂交技术在产前诊断中的应用

目的:评价改良荧光原位杂交(fluorescent in situ hybridization,FISH)技术在产前诊断中的应用。方法:用改良FISH技术检测119例孕16~24周孕妇的羊水间期细胞及10例孕25~32周胎儿脐血间期细胞,5例孕9~12周绒毛间期细胞,每例均行常规染色体核型分析。结果:应用改良FISH法,所有样本均在6h内获得检测结果,除2例羊水培养失败外,其余样本均在3周内获得细胞遗传学诊断。两种方法均检出特氏综合征、18-三体综合征、21-三体综合征各1例,另5例常规染色体核型分析异常,因超出检测范围,FISH法未能检出,所有样本的两种方法检测结果均一致。结论:经改良后的FISH技术缩短了诊断时间,缓解了孕妇及家属的焦虑心情,且可用于多种不同样本的检测,因其高效、省时、取材多样等优点在产前诊断具有重要的临床价值。     

Relative efficiency of FISH on metaphase and interphase nuclei from non-mosaic trisomic or triploid fibroblast cultures

Chromosome specific probes that are used in interphase fluorescence in situ hybridization (FISH) analysis are usually tested on disomic control samples. When used for preimplantation or prenatal diagnosis the aim is to detect aneuploidy, most frequently trisomy. In this study, skin fibroblast cultures from non-mosaic trisomic and triploid fetuses were analysed by FISH to assess probe efficiency regarding interphase detection of trisomy. Skin fibroblast cultures were used because they are considered to be stable in culture. FISH experiments were performed using centromeric probes for chromosomes X, Y, 18 and locus specific probes for chromosomes 13 and 21. In metaphase nuclei, the expected signals were found in 100% of at least 30 metaphases counted on each sample and this also confirmed non-mosaicism in agreement with conventional karyotyping of the fetuses. On interphase nuclei, however, only 80-89% of nuclei per population displayed the expected signals for autosomal probes and 90% for probes for the sex chromosomes. For each probe, a range of percentages was obtained that can be regarded as indicative of non-mosaic trisomy in uncultured specimens. In the case of prenatal samples, the expected presence of maternal cells may lead to a lowering of the threshold for a trisomic diagnosis. In the case of preimplantation diagnosis, the accuracy can be improved by the use of two probes per chromosome or by the analysis of two cells from each embryo.     

Rapid prenatal diagnosis of Down syndrome using quantitative fluorescence in situ hybridization on interphase nuclei

OBJECTIVES: Presently, conventional cytogenetic analysis of metaphase chromosomes remains the reference approach in prenatal diagnosis. However, this method is labor-intensive and time-consuming. The first step toward the rapid identification of aneuploidies is achieved by interphase fluorescence in situ hybridization (FISH) with centromeric or locus-specific probes. Spot counting using this type of probes is a reliable approach, but is very time-consuming with some technical and biological limitations. In this study, we present a new FISH method using image cytometry for the detection of trisomy 21 within interphase nuclei. METHODS: The method is based on a comparative quantitation of the fluorescence signals emitted by whole chromosome 21 and 22 painting probes cohybridized on interphase nuclei. The chromosomal imbalance was determined with an automated image cytometer by detecting an abnormal ratio of both fluorescence emissions when compared with the ratio obtained in normal cells. RESULTS: Ten blood samples and twenty amniotic fluids were analyzed. Results from FISH and standard cytogenetics were compared and 100% correlation was achieved. CONCLUSIONS: This method, which enables an easy detection of chromosomal imbalances without a need for metaphase preparations, can be applied to the diagnosis of trisomy 21 and extended to other disorders with chromosomal imbalances. Compared to other interphase FISH techniques, it avoids spot-scoring difficulties.     

荧光原位杂交技术在检测假性肥大型肌营养不良症缺失型携带者中的应用

目的:应用荧光原位杂交(FISH)筛查技术检测假性肥大型肌营养不良症(DMD/BMD)缺失型携带者。方法:以外显子特异Cosmid DNA为探针(含18个外显子),采用中期和间期单色FISH技术,对9例正常男、女性及来自不同缺失型DMD/BMD家系的5例女性外周血标本、来自健康孕妇的2例羊水和2例绒毛标本进行分析。结果:72～100％外周血淋巴细胞中期相或间期核、60～70％羊水细胞间期核、95～99％绒毛细胞间期核显示预期信号。FISH检出1名、排除2名缺失型携带者。结论:充分利用FISH技术优点,结合现有其它技术,可有效筛查DMD/BMD缺失型携带者,并为女性胎儿DMD/BMD缺失型携带者产前诊断奠定基础。     

Rapid prenatal diagnosis of trisomy 21 in 5049 consecutive uncultured amniotic fluid samples by fluorescence in situ hybridisation (FISH).

OBJECTIVES: This was a retrospective study on the results of interphase fluorescence in situ hybridization (FISH), performed routinely for chromosome 21 and on ultrasonographic indications for chromosomes 13, 18, X and Y in a series of 5049 amniotic fluid samples. METHODS: Interphase FISH for chromosome 21 was performed in 5049 consecutive amniotic fluid samples for the rapid prenatal diagnosis of Down syndrome. Aneuploidy for four other chromosomes (13, 18, X and Y) was tested following ultrasonographic indications. Karyotypes from standard cytogenetic analysis were compared to the FISH results. RESULTS: Using conventional cytogenetics 3.6% (183/5049) chromosomal anomalies were detected. After exclusion of familial chromosome rearrangements, i.e. balanced autosomal reciprocal or Robertsonian translocations (30/5049) and inversions (19/5049), 2.65% chromosomal anomalies (134/5049) were diagnosed. Of this group 0.18% (9/5049) were chromosomal rearrangements not detectable by FISH and 2.47% (125/5049) were numerical chromosomal anomalies detectable by interphase FISH for chromosomes 13, 18, 21, X and Y. With routine interphase FISH for chromosome 21 and FISH on echographic indication for the other four chromosomes we detected 107/125 of these numerical chromosomal anomalies, i.e. 85.6%. All 70 cases of trisomy 21 were detected by FISH and confirmed with conventional cytogenetics (sensitivity=100%) and there were no false-positive results (specificity=100%). Maternal cell contamination of amniotic fluid samples occurred in 1.27% (64/5049) of samples; 0.26% (13/5049) of these samples were uninformative by FISH due to maternal cell contamination (12/5049) or absence of nuclei in one sample (1/5049). CONCLUSION: In this group of 5049 samples we found that FISH is a reliable technique for the rapid prenatal diagnosis of trisomy 21. The number of uninformative cases due to maternal cell contamination was low. The strategy to perform FISH for chromosome 21 in all samples and only on ultrasonographic indication for the four other chromosomes (13, 18, X and Y) followed by standard cytogenetics is effective.     

胚胎染色体非整倍体筛查用于平衡易位携带者植入前的遗传学诊断

目的 交信号和1个Y染色体杂交信号者,则诊断为整倍体胚胎;异常杂交信号的胚胎则诊断为非整倍体胚胎.结果 (1)11个平衡易位的PGD周期中,选出杂交信号完整的130个细胞核进行分析,FISH共分析了937个荧光杂交信号,其中整倍体细胞核38个,共有304个杂交信号;其余92个为非整倍体细胞核.(2)在92个非整倍体细胞核中,Ⅰ、Ⅱ及Ⅲ级胚胎的比例分别为20个(22%)、36个(39%)及36个(39%);38个整倍体细胞核中,Ⅰ、Ⅱ及Ⅲ级胚胎的比例分别为13个(34%)、17个(45%)及8个(21%),两者的Ⅰ、Ⅱ及Ⅲ级胚胎数分别比较,差异均无统计学意义(P＞0.05).虽然染色体整倍体率在不同级别胚胎中的分布比较,差异均无统计学意义(P＞0.05),但优质胚胎(Ⅰ级+Ⅱ级)中非整倍体率仍为60%(56/92).(3)平衡胚胎来源的卵裂球细胞核整倍体率(71.4%,30/42)明显高于非平衡胚胎来源的卵裂球细胞核整倍体率(9.1%,8/88),两者比较,差异有统计学意义(P＜0.05).平衡胚胎来源的卵裂球细胞核非整倍体率(包括三体、单体、复杂非整倍体、单倍体、多倍体)明显低于非平衡胚胎来源的卵裂球细胞核非整倍体率(P＜0.05).结论 平衡易位携带者的胚胎中有较高的非整倍体率,因此,胚胎非整倍体筛查在平衡易位携带者的PGD中有重要价值和临床意义.

Abstract：

Objective To determine the importance of aneuploidy screening in preimplantation genetic diagnosis for the couples of chromosome translocation carriers. Methods To perform 11 prenatal genetic disgnosis (PGD) cycles for 7 couples of chromosome translocation carriers from January 2006 to March 2009 in the Reproductive Medical Center, First Affiliated Hospital of Zhengzhou University. To re-analyze the well-fixed, non-multinuclear and non-debris nuclei using the probes of LSI 13, 18, 21,CEPX, CEPY to detect the aneuploidy rate which come from the PGD cycles of the couples of chromosome translocation carriers. The euploid embryo was defined as two fluorescence in situ hybridization (FISH)signals of LSI 13, 18, 21 respectively and two signals of CEPX, or one signal of CEPX and one signal of CEPY. The other abnormal signals were defined as aneuploid embryo. Results (1) A tolal of 130 nuclei from 11 PGD cycles got the integrated re-FISH signals. Nine hundred and thirty-seven FISH signals were analysized, including 304 signals from 38 euploid nuclei and the others from 92 aneuploid nuclei. (2) The number of the aneuploid nuclei from grade Ⅰ , Ⅱ and Ⅲ embryo was 20 (22%), 36(39%), and 36(39%). The number of the euploid nuclei from grade Ⅰ , Ⅱ and Ⅲ embryo was 13(34%), 17(45%),and 8(21%). There was no significant difference of aneupioidy rate between the embryos form different grades (P＞0.05). However, the rate of aneuploid nucleus from good quality embryos (grade Ⅰ + grade Ⅱ) was 60% (59/92). (3) The euploidy rate was 71.4% (30/42) from balanced embryos, while 9.1%(8/88)from unbalanced embryos. There was significant difference between them (x2=53.4, P＜0.05).The rate of aneuploidy from balanced embryos was lower than those from unbalanced embryos (P＜0.05).Conclusions Since higher rate of aneuploidy was detected in embryos of the couples of chromosome translocation carriers. It is advisable to recommend the FISH re-analysis for aneuploidy screening to preimplantation genetic diagnosis for the couples of chromosome translocation carriers.     

定量荧光PCR在唐氏综合征快速产前诊断中的应用研究

目的 :了解中国人 D2 1 S1 1、D2 1 S1 2 70、D2 1 S2 2 6、D2 1 S1 41 1四个短串联重复序列 ( STR)位点的多态性信息含量 ( PIC) ,建立定量荧光 PCR快速产前诊断唐氏综合征的方法。方法 :以染色体2 1 q2 1～ q2 2 .3区段内四个短串联重复序列作为遗传标记 ,采用定量荧光 PCR对 5 0例正常人外周血 DNA进行分析 ,计算中国人该四对 STR位标的多态性信息含量 ( PIC) ,并用该方法对 1 1例正常孕妇羊水 DNA进行分析 ,及对唐氏综合征血清生化指标筛查阳性孕妇羊水标本进行产前诊断。结果 :D2 1 S1 1、D2 1 S1 2 70、D2 1 S2 2 6、D2 1 S1 41 1的多态性信息含量分别是 0 .90 2、0 .889、0 .5 2 1、0 .775 ,建立了定量荧光 PCR产前诊断唐氏综合征的方法。应用该技术产前诊断出 3例唐氏综合征患儿 ,并经染色体核型分析所证实。结论 :以上四对 STR在中国人中均具有较高多态性信息含量 ,可应用于唐氏综合征的定量荧光 PCR产前诊断技术中     

Fluorescence in situ hybridization of chorionic interphase cells for prenatal screening of Down syndrome

OBJECTIVE: Our purpose was to determine the usefulness and reliability of fluorescence in situ hybridization on interphase chorionic villi cells in the prenatal diagnosis of Down syndrome. METHODS: A total of 336 samples of chorionic villi were analysed by direct chromosome preparation and FISH with a DNA probe specific to chromosome 21. The samples were obtained as part of the routine obstetric investigation and management. RESULTS: The sampling and direct karyotyping was successful in all cases. At least 50 cells were valuable by FISH in 331 of 336 samples. Both methods showed Down syndrome in 12 cases. The follow-up investigations showed that there was no false-negative or false-positive result following these procedures. CONCLUSION: Based on these results and the fact that it is possible to analyse by interphase FISH at least ten times more cells than by conventional cytogenetic methods, and these cells originate from different tissues of chorionic villi, it is concluded that FISH increases the reliability of the diagnosis. Nevertheless, more data are needed for correct statistical analysis. Since this method is cheaper and gives diagnosis earlier than cell culture, the combination of direct chromosome preparation and FISH on chorionic villi is offered for prenatal Down syndrome screening.