对孕妇外周血中胎儿细胞进行基因检测的三种方法比较

目的　建立用孕妇外周血中胎儿细胞进行基因分析的技术。方法　采用引物延伸预扩增(primed extension preamplification,PEP)法加 PCR、多重引物原位合成技术 (primed in situ labeling,PRINS)和巢式聚合酶链反应 (nested PCR)检测孕妇外周血中单个胎儿细胞的性别决定区 Y基因 (sex- de-termination region Y gene,SRY)基因片段。结果　 PEP加 PCR方法检测 SRY基因的敏感性为 97.39%(14 9/ 15 3) ,特异性为 99.17% (119/ 12 0 )。PRINS技术检测 SRY基因的敏感性为 97.5 6 % (40 / 4 1) ,特异性为10 0 % (35 / 35 )。巢式 PCR检测 SRY基因的敏感性为 80 .0 0 % (2 4 / 30 ) ,特异性为 87.5 0 % (14 / 16 )。结论　PEP加 PCR技术和 PRINS技术是对孕妇外周血中单个胎儿细胞进行基因诊断的可靠技术 ,其敏感性高、特异性强 ,有望成为利用孕妇外周血中单个胎儿细胞进行非创伤产前诊断的常规方法。     

两例Y染色体部分缺失胎儿的产前诊断

目的对两例Y染色体部分缺失胎儿进行产前诊断。方法采用常规G显带及C显带技术分析胎儿及父亲的核型,采用荧光原位杂交(fluorescence in situ hybridization,FISH)、染色体拷贝数变异检测技术(copy number varaition sequencing,CNV-seq)性别决定基因(sex region of Y chromosome,SRY)检测技术及无精子因子(azoospermia factor,AZF)检测技术检测胎儿DNAO结果2例胎儿羊水染色体在320〜400条带水平均提示46,XN,del(Y)(qll.2),Y染色体着丝粒探针FISH检测结果均提示Y染色体数目未见异常。2例胎儿父亲外周血染色体核型均未见明显异常。胎儿羊水DNA拷贝数检测提示一例胎儿Y染色体q 11.221-ql2处缺失12.88 Mb,涉及全部AZFb+AZFc区域;另一例胎儿Y染色体qll.21-ql2处缺失14.84 Mb,涉及全部AZF区域。2例胎儿羊水SRY基因检测提示SRY基因阳性,SKY基因编码区未检测到已报道的致病点突变。2例胎儿基因检测提示存在AZF部分或全部缺失。结论联合多种技术有助于明确诊断Y染色体结构异常。CNV-seq检测有利于快速筛查胎儿Y染色体微缺失,可做为对染色体核型分析的补充和验证的方法。     

应用引物原位标记技术快速检测SOX2基因

目的 应用引物原位标记(primed in situ labeling,PRINS)代替荧光原位杂交技术对SOX2基因进行快速检测.方法 常规制备人外周血染色体并制片,利用SOX2基因特异性引物在染色体上原位扩增包含生物素标记的探针.用酪胺信号放大(tyramide signal amplification,TSA)生物素系统处理经标记的探针.最后用链霉亲和素-德克萨斯红(streptavidin-Texas red)对生物素信号进行荧光染色,用DAPI染料对染色体进行复染.作为对照,MCF-10F细胞用慢病毒载体转染导人SOX2基因,使用相同的方法检测结合位点.结果 VideoTesT-FISH软件分析提示,实验组3号染色体长臂端有特异红色荧光信号表达,空白组与未经TSA信号处理的对照组则无特异性的红色荧光信号.经过转染的MCF-10F细胞则表现出不同的SOX2基因整合效果.结论 PRINS技术利用高敏感度的原位PCR技术(in situ PCR)结合荧光标记的脱氧核苷酸可在细胞内原位合成形成探针,可大大减少探针的费用与检测的时间,提高检测效率.在诱导多能干细胞的鉴定与分类中具有较为广泛的应用前景.     

三例畸变Y染色体的重组形式及定位分析

目的 对3例畸变Y染色体进行定位分析并确定其重组形式.方法 采用染色体G显带、多重连接依赖探针扩增(multiplex ligation dependent probe amplification,MLPA)、荧光原位杂交(fluorescence in situ hybridization,FISH)、Y染色体多个序列标签位点(sequence tagged site,STS)及Illumina人类全基因组单核苷酸多态性芯片扫描(single nucleotide polymorphisms array,SNP-array)等多种技术.结果 3例患者染色体G显带核型均为46,X,+ mar.MLPA检测发现例1 SRY、ZFY、UTY基因重复;例2 SRY、ZFY基因重复、UTY基因缺失;例3X染色体短臂/Y染色体短臂(X/Yp)、X染色体长臂/Y染色体长臂(X/Yq)亚端粒区域基因拷贝数减少.Y染色体STS分析提示:例1的SRY及Y染色体AZFa区sY84、sY86、AZFb区sY1227存在,但sY1228及AZFc区多个STS缺失,断裂点位于AZFb区sY1227和sY1228之间;例2的SRY及着丝粒区域sY1200存在,其余STS均缺失;例3的SRY及AZF多个STS均存在.SNP-array扫描提示,例1 Yp11.31-p11.2区重复,Yq11.22-q11.23区缺失,缺失片段约为5.18 Mb;例2 Yp11.31-p11.2区重复,重复片段为3.724 Mb,Yq11.21-q11.23区域缺失,缺失约14.644Mb;例3 X/Yp亚端粒区域(PAR) p22.33单拷贝缺失,X/Yq亚端粒区域(PAR) q28单拷贝缺失.FISH分析提示,例1和例2细胞中期原位杂交核型均为46,X,+ mar.ish(Y)(SRY++,DYZ3++,DYZ1-).综合分析:例1和例2的标记染色体均为短臂等臂双着丝粒Y染色体.分子核型:例1为46,X,idic (Y)(q11.23);例2为46,X,idic(Y) (q10);例3为标记染色体为环状Y,核型为46,X,r(Y)(p1 1q12).结论 Y染色体畸变形式多样,选用MLPA、Y染色体STS、FISH、SNP-array等多项技术联合诊断是确定其断裂点及重组形式的重要手段.     

应用引物原位标记技术快速检测18三体综合征

目的　探索应用改良的引物原位标记技术快速检测未培养羊水细胞间期核的可能性。方法采用改良的引物原位标记 (primed in situ labeling,PRINS)技术 ,对 2 6 2份羊水细胞中 18号染色体进行分析检测。结果　在未培养羊水细胞间期核和培养细胞的中期分裂相中 ,PRINS技术均能特异性地检测 18号染色体 ,PRINS反应的成功率为 95 %。并发现两个样本为 18三体综合征。结论　引物原位标记技术是一种简便、快速、经济的染色体检测方法 ,具有较强的敏感性和特异性 ,有助于对传统细胞遗传学的分析。     

快速无创性产前诊断唐氏综合征的初步研究

目的建立快速无创性产前诊断唐氏综合征的有效诊断模式。方法从98名孕妇中筛选出12名高度怀疑唐氏妊娠者,当日流式细胞术分选母血中的胎儿有核红细胞（Fetal nucleated red blood cells,FNRBCs）,制备滴片后,次日进行多重引物原位杂交（muti—primed in situ labeling,multi—PRINS）检测胎儿细胞21号、Y染色体。结果均可在两日内得到诊断结论,诊断10例正常胎儿和两例男性唐氏综合征胎儿,与实际胎儿核型完全一致。结论流式分选母血中胎儿有核红细胞后多重PRINS技术检测细胞染色体可作为快速无创性产前诊断的有效模式,并可为其他非整倍体异常和单基因病的快速无创性产前诊断提供有效参考。     

一例性发育异常患儿的临床及遗传学分析CSCD

目的报道一例性发育异常患儿的诊疗过程和临床特点,并对其进行病理学、影像学以及遗传学研究。方法收集患儿的临床资料,并对其进行染色体核型分析、荧光原位杂交(fluorescence in situ hybridization,FISH)、拷贝数变异分析、SRY基因检测和多重连接探针扩增检测。结果患儿社会性别为男性,因"尿道下裂术后、乳房发育"就诊。影像学检查显示双乳增生,变异精囊腺,幼稚子宫,右侧睾丸体积小。病理学检查表明患儿左侧性腺为卵睾,右侧为睾丸。病理结果显示乳腺纤维腺瘤样变。染色体核型为46,XX。FISH结果显示46,XX.ish(DXZ1×2,SRY×0)。基因检测提示NR0B1、PHEX、Cxorf21、GJB1、PQBP1、COL4A5基因重复,SRY基因存在,UYT基因缺失。结论对于生殖器异常、男性乳腺发育的患者应及早进行影像学、内分泌和遗传学检查,必要时进行基因检测以明确诊断。性发育异常患儿的个体化治疗需要多学科合作。     

8例性发育异常患者SRY基因分析

目的对8例性发育异常患者进行细胞遗传学及分子遗传学检查以探讨性别发育异常与SRY基因关系.方法用PY3.4,X着丝粒,SRY特异探针进行荧光原位杂交,用于分析性发育异常病人Y染色体及SRY基因异位情况.聚合酶链反应(PCR)扩增SRY基因,直接测序检测SRY基因突变.结果 2例46,XX男性,1例46,XY女性,1例45,X/46,XY嵌合体及1例46,X,t(Y;Y)(p11;q11)男性患者SRY基因均为阳性,直接测序未发现SRY基因阳性患者该基因突变.剩余1例46,XX男性,1例46,XY男性及1例46,XY女性患者SRY基因为阴性.FISH技术证实2例46,XX且SRY基因阳性的男性患者SRY基因易位至X染色体短臂末端.结论 SRY基因是人类性别决定的主导基因,但尚有其他基因参与性别分化.     

FISH技术在骨髓/血液标本中的应用体会

荧光原位杂交(fluorescence in situ hybridization,FISH)技术对白血病预后相关基因的检测结果已作为白血病危险度分层的参考指标。本文现介绍FISH技术在骨髓/血液标本中的一些应用体会。     

用实时荧光定量PCR方法检测母血中的胎儿SRY基因

目的　从孕妇外周血浆中分离出胎儿DNA ,并加以鉴定 ,预防X连锁遗传病患儿的出生。方法　从孕早期、中期共 3 0 0名孕妇外周血浆中分离胎儿DNA ,用实时荧光定量聚合酶链反应 (fluorescencequantitativepolymerasechainreaction ,FQ PCR)的方法检测其中的Y性别决定区 (sex determiningregionY ,SRY)基因。结果　孕早期怀男胎的孕妇 82名 ,70名SRY基因阳性 ,其平均浓度为 ( 5 8.82± 2 0 .90 )拷贝 /ml,中位数为 5 8.5 0拷贝 /ml。孕中期怀男胎的孕妇 90名 ,SRY基因均为阳性 ,平均为 ( 15 2 .0 8± 62 61)拷贝 /ml,中位数为 14 9.3 5拷贝 /ml。怀女胎的孕妇均为阴性。结论　用实时荧光定量PCR的方法最早在孕42天的孕妇外周血浆中就可以检测到胎儿SRY基因 ,随孕周的增加 ,母血中胎儿DNA的量也在逐渐增加。实时荧光定量PCR技术在进行无创伤性产前性别诊断中有重要的价值。     

Localization of SRY by primed in situ labeling in XX and XY sex reversal

Primed in situ labeling (PRINS) can be used to localize DNA segments too small to be detected by fluorescence in situ hybridization. By PRINS we identified the SRY gene in two XX males, a woman with XY gonadal dysgenesis, and an azoospermic male with Xp-Yp interchange. Because PRINS has been used generally in the study of repetitive sequences, we modified the technique for study of the single copy 2. 1-kb SRY sequence. SRY signals were identified at band Yp11.31p11.32 in normal XY males and in the woman with XY gonadal dysgenesis. SRY signals were identified on Xp22 in one XX male but not in the other. They were identified in the corresponding region (Xp22) of the der(X) in the azoospermic male with Xp-Yp interchange. SRY signals were not observed in normal XX females. Presence of SRY in DNA samples from the various subjects was confirmed by polymerase chain reaction. We conclude that PRINS is ideal for rapid localization of single copy genes and small DNA segments in general.     

Tetrasomy 8 is associated with a major cellular proliferative advantage and a poor prognosis. two cases of myeloid hematologic disorders and review of the literature

We report two cases of acute myeloid leukemia (AML) with tetrasomy 8 detected in patients' bone marrow samples using chromosome GTG-banding, fluorescence in situ hybridization (FISH) and primed in situ labeling (PRINS) techniques. Case 1 was a myelodysplastic syndrome (MDS) in transition to AML-M4 and case 2 was an AML-M2. In case 1, the tetrasomy 8 was found in 40% of metaphase cells and constituted the only chromosome abnormality. In case 2, it was accompanied by a double Ph, trisomy 18 and disomy Y and was found in 68% of metaphase cells. However, FISH and PRINS techniques revealed the coexistence of tetrasomy 8 and trisomy 8 in interphase nuclei of both cases. When the proportion of cells with tetrasomy 8 was compared between metaphases and interphase nuclei, it showed a much higher percentage of cells with tetrasomy 8 in metaphases than in interphase nuclei. Moreover, in case 2, although multi-PRINS and FISH-PRINS techniques showed other populations of interphase nuclei with different combinations of chromosome anomalies with respect to the copy numbers for chromosomes 8, 18, Y and Ph, only cells that contained either a single Ph or tetrasomy 8 plus trisomy 18, disomy Y, and double Ph could be seen in metaphases. This strongly suggests that tetrasomy 8 confers a higher proliferative advantage to cells. Our cases also show that the tetrasomy 8 is associated with a poor prognosis.     

人类中期染色体三色引物原位标记技术研究

目的探索应用优化的三色引物原位标记技术同时标记多条人类外周血淋巴细胞培养中期染色体的可行性。方法采用双色引物原位标记预实验检测外周血中期淋巴细胞的X、Y染色体以摸索和优化引物应用条件和反应顺序。以优化的三色技术同时标记正常样本及克氏综合征样本(47,XXY)的18、X、Y染色体以验证其有效性。结果在3h之内特异性的同时标记了18、X、Y染色体,双色和三色反应的标记率均达到90%以上。克氏综合征样本准确显示了2条18号染色体,2条X染色体和1条Y染色体。结论非ddNTP阻断的多色引物原位标记技术能够快速而准确地判别染色体数目异常的外周血淋巴细胞样本,原位标记由于有内对照而更加具有说服力。     

一种能精确检测人间期细胞核中21号染色体拷贝数的DNA探针

目的制备能精确检测人类间期细胞核中２１号染色体拷贝数的ＦＩＳＨ探针。方法利用万能引物ＰＣＲ法,从定位于人２１ｑ１１的ＹＡＣ克隆８８１Ｄ２分离制备ＤＮＡ探针,并用于与８例正常人和５例２１三体患者的外周血淋巴细胞中期相和间期核,及经细胞松弛素Ｂ（ｃｙｔｏｃｈａｌａｓｉｎＢ）诱导的双核细胞进行ＦＩＳＨ分析。结果该探针具有以下特点：（１）长度集中于３５０～７５０ｂｐ;（２）其靶序列位于２１号染色体长臂上且紧靠着丝粒;（３）特异性强;（４）杂交信号明亮,容易辨认;（５）对中期相及间期细胞核中２１号染色体的检出率分别高达９９．６０％和９８．４０％。结论制备的ＤＮＡ探针能精确检测人类间期细胞核中２１号染色体的拷贝数,且适用于细胞分裂时２１号染色体分离情况的研究     

Rapid in situ detection of chromosome 21 by PRINS technique

The “PRimed IN Situ labeling” (PRINS) method is an interesting alternative to in situ hybridization for chromosomal detection. In this procedure, chromosome labeling is performed by in situ annealing of specific oligonucleotide primers, followed by primer elongation by a Taq polymerase in the presence of labeled nucleotides. Using this process, we have developed a simple and semi-automatic method for rapid in situ detection of human chromosome 21. The reaction was performed on a programmable temperature cycler, with a chromosome 21 specific oligonucleotide primer. Different samples of normal and trisomic lymphocytes and amniotic fluid cells were used for testing the method. Specific labeling of chromosome 21 was obtained in both metaphases and inter-phase nuclei in a 1 hour reaction. The use of oligonucleotide primer for in situ labeling overcomes the need for complex preparations of specific DNA probes. The present results demonstrate that PRINS may be a simple and reliable technique for rapidly detecting aneuploidies. © 1995 Wiley-Liss, Inc.     

应用双色引物原位标记技术快速检测X和Y染色体

目的发展快速检测染色体的技术，探索应用改良的双色引物原位标记（primed in situlabeling，PRINS）技术快速检测未培养细胞间期核可能性。方法采用改良的双色技术，对205份羊水细胞中X和Y染色体进行分析检测。结果在未培养羊水细胞间期核和培养细胞的中期分裂相中，PRINS技术均能特异性地检测X和Y染色体，PRINS反应的成功率为98％，1个样本检出为47，XXY。结论双色引物原位标记技术是一种快速、简便、经济的染色体检测方法，具有较强的特异性和敏感性，有助于快速诊断染色体畸变。     

应用FISH和PCR技术鉴别Turner综合征患者标记染色体起源

目的　为指导遗传咨询,鉴别Turner 综合征患者微小标记染色体起源。方法　选择SRY 基因编码区1 对特异寡核苷酸引物、X 和Y 染色体特异探针,采用PCR 及荧光原位杂交方法,对8 例具有Turner 综合征体征的患者进行标记染色体分析。结果　5 例患者标记染色体起源于X染色体;3 例起源于Y 染色体,其中2 例SRY 基因序列扩增,可见男性特异扩增带,另1 例无男性特异扩增带。结论　FISH 与PCR 技术结合可准确鉴别标记染色体,对选择治疗方案及了解核型与表型关系有指导意义。     

Combined use of PRINS and FISH in the study of the dystrophin gene

The efficacy of fluorescence in situ hybridization (FISH) may be limited in specific applications by low‐resolution sensitivity. Primed in situ labeling (PRINS) is based on specific hybridization of an unlabeled oligonucleotide with a denatured template and synthesis of a single‐strand DNA in situ. This method may represent a powerful alternative to FISH for gene mapping because of its ability to generate multiple independent signals within the same gene segment. We investigated the specificity of signals produced by a modified PRINS protocol combining a centromeric probe for the X‐chromosome with specific primers for 3′‐ and 5′‐terminal regions of the dystrophin gene. In approximately 70% of nuclei from male and female subjects, we detected one or two large signals (X‐chromosome centromere) and two or four smaller signals (the two regions of the dystrophin gene). Specific hybridization of the oligonucleotides on Xp was demonstrated by localization of the smaller (dystrophin) and larger (X‐centromere) signals on the same chromosome. Simultaneous hybridization with a centromeric probe and gene‐specific oligonucleotides allowed localization of PRINS signals, and assessment of the specificity of the primers used for hybridization. This approach could facilitate identification of female carriers of small intragenic deletions in the dystrophin gene. © 2001 Wiley‐Liss, Inc.     

Combined use of PRINS and FISH in the study of the dystrophin gene.

The efficacy of fluorescence in situ hybridization (FISH) may be limited in specific applications by low-resolution sensitivity. Primed in situ labeling (PRINS) is based on specific hybridization of an unlabeled oligonucleotide with a denatured template and synthesis of a single-strand DNA in situ. This method may represent a powerful alternative to FISH for gene mapping because of its ability to generate multiple independent signals within the same gene segment. We investigated the specificity of signals produced by a modified PRINS protocol combining a centromeric probe for the X-chromosome with specific primers for 3'- and 5'-terminal regions of the dystrophin gene. In approximately 70% of nuclei from male and female subjects, we detected one or two large signals (X-chromosome centromere) and two or four smaller signals (the two regions of the dystrophin gene). Specific hybridization of the oligonucleotides on Xp was demonstrated by localization of the smaller (dystrophin) and larger (X-centromere) signals on the same chromosome. Simultaneous hybridization with a centromeric probe and gene-specific oligonucleotides allowed localization of PRINS signals, and assessment of the specificity of the primers used for hybridization. This approach could facilitate identification of female carriers of small intragenic deletions in the dystrophin gene.