Simultaneous Detection of Chromosomes X, Y, 13, 18, and 21 by Fluorescence In Situ Hybridization in Blastomeres Obtained from Preimplantation Embryos

Purpose. Simultaneous fluorescence in situ hybridization (FISH) was used in a preimplantation genetic diagnosis program to determine which embryos were normal for chromosomes X, Y, 13, 18, and 21. Methods: Single blastomeres were disrupted and attached to glass slides using acetic acid and ethanol. Using a ratio mixture of chromosome enumeration DNA probes in combination with locus-specific identifier DNA probes, FISH was performed for the identification of chromosomes X, Y, 13, 18, and 21. Results: Fourteen couples enrolled in IVF produced 134 embryos for biopsy. Blastomeres subjected to five-color FISH revealed that 22% of embryos were normal for chromosomes X, Y, 13, 18, and 21. In addition, 52% were abnormal and no results could be detected for 25%. Twelve couples underwent embryo transfer, two couples did not receive embryos due to lack of any normal embryos, and three couples became pregnant. Conclusions: The simultaneous detection of five-color FISH is a feasible method to detect aneuploidy in preimplantation embryos from women of advanced maternal age.     

Improving the Fixation Method for Preimplantation Genetic Diagnosis by Fluorescent in Situ Hybridization

Purpose: Our purpose was to modify a fixation method using Tween-20 and HCl (TH) and to compare it with a protocol using methanol and acetic acid (MA) for the improvement of preimplantation genetic diagnosis by fluorescence in situ hybridization (FISH). Methods: Single blastomeres were allocated to either the TH or the MA procedure. The two methods were compared to evaluate efficiency of fixation and the intensities of FISH signals. Results: With the TH method, 123 (93.9%) of 131 blastomeres were fixed, while only 95 (78.5%) of 121 were fixed with MA. Average scores for the intensity of FISH signals were significantly stronger for TH than for MA (P < 0.05). There was also a significant difference in signal intensity scores between the two methods for type-3 nuclei. Conclusions: Our results indicate that not only are fewer nuclei lost during fixation but also stronger FISH signals can be obtained with the TH method. Thus, modified TH can improve the overall efficiency of preimplantation genetic diagnosis.     

胚胎植入前遗传学诊断10个周期的临床分析

目的:初步探讨使用荧光原位杂交(FISH)方法对染色体异常患者进行胚胎植入前遗传学诊断(PGD)的临床意义。方法:7对不孕夫妇采用长方案控制性超排和卵胞浆内单精子注射,受精后d3胚胎活检、卵裂球固定和FISH,d4或d5择合适胚胎移植。结果:7对夫妇共进行10个PGD周期。获卵251个,可供活检胚胎133个,活检卵裂球207个,胚胎活检成功率为96.2%(128/133)。128个成功活检胚胎的197个卵裂球,其单细胞固定率为93.9%(185/197),FISH信号率为90.8%(168/185)。10个周期共移植22个胚胎,3例获得妊娠,并均足月分娩健康婴儿,其中1例孕妇平衡易位携带者于孕中期时,羊水核型分析为平衡易位携带者。结论:应用FISH方法进行PGD,是遗传病高危夫妇预防流产和染色体异常患儿出生的有效手段。     

用荧光原位杂交技术检测唐氏综合征

目的: 探讨用荧光原位杂交技术在检测唐氏综合征中的应用价值。方法: 以Biotin标记的DSCR21q22.3探针与经处理的20例唐氏综合征患者标本外周血中期染色体及其间期细胞核进行原位杂交,统计杂交信号数量。结果: 14例唐氏综合征患者出现3个杂交信号的细胞,染色体和间期细胞核杂交平均出现率分别为98.79％和98.46％,与染色体检测的结果一致;其余染色体核型检测为嵌合体的6例患者,染色体和间期细胞核中3个杂交信号细胞平均出现率分别为75.33％和7 3.50％, 2个杂交信号细胞平均出现率分别为22.67％和21.33％。结论: 荧光原位杂交技术检测唐氏综合征具有快速、敏感度高、信号强、背景低、直观安全等优点,故FISH技术在临床遗传病检测领域中具有重要的应用价值和发展前景。     

Preimplantation Diagnosis by FISH: The Rambam Experience

Purpose: Our purpose was to summarize our experience gained using fluorescence in situ hybridization for preimplantation diagnosis at the Rambam Medical Center. Methods: Seventy-three embryos (29 cycles) were analyzed for preimplantation diagnosis for the following indications: advanced maternal age (>39 years), X-linked diseases, poor-quality embryos, repeated failure in vitro fertilization cycles and fast-dividing embryos. An additional 38 embryos with unequal pronuclei size were examined for ploidy. Biopsy of embryonic blastomeres was performed at the six- to eight-cell stage. Five fluorescence probes, for chromosomes X, Y, 13, 18, and 21, were applied for ploidy detection. Results: Eighty-four (87%) blastomeres of the 73 embryos analyzed showed clear signals. Six of the blastomeres were lost during spreading. Two of the embryos were destroyed following biopsy. No nucleus was found in five of the blastomeres, while in nine, more than one nucleus was verified. Transfer was performed in 10 patients (32 embryos). Two pregnancies were achieved. Two healthy babies were born. Fifty-seven percent of the fast-dividing embryos demonstrated normal signals. In two groups of embryos of unequal pronuclei size, following conventional insemination and intracytoplasmic sperm injection, 50 and 11.4% demonstrated normal signals. Conclusions: The efficiency of florescence in situ hybridization for aneuploidy detection is 87 and 97% for autosomes and gonosomes, respectively. The preimplantation genetic diagnosis is suitable for selected in vitro fertilization cases including fast-dividing embryos and embryos with unequal pronuclei size following regular in vitro fertilization.     

荧光原位杂交与染色体核型分析应用于自然流产病因学诊断的比较研究

目的:分析并比较荧光原位杂交技术(fluorescence in situ hybridization,FISH)及普通染色体核型分析技术在自然流产中的诊断意义。方法:以早孕自然流产的患者为研究对象,共201例。将同一孕周的患者随机分为A组和B组,A组(n=100)进行绒毛培养加染色体核型分析,B组(n=101)进行FISH分析,另在A、B组孕6~11周患者中每一孕周各随机选取1例,每组6例,共12例同时进行2种技术分析,并比较结果。结果:染色体核型分析成功率为66%,其中核型异常率为30.3%;FISH成功率为100%,其中核型异常率为46.5%;2种检测技术检测出的异常核型率比较有统计学差异(P=0.036)。结论:2种分析技术对异常核型的检出率有明显的差异,FISH更容易成功,更能反应胚胎的染色体数目;染色体核型分析结合FISH技术能有效诊断自然流产的染色体异常。     

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．     

父源性染色体异常胚胎植入前遗传学诊断的最新研究进展

染色体异常是导致男性不育的一个重要原因。不同类型染色体异常的生殖细胞进行减数分裂时形成不同类型的配子,且各种异常配子所比例的实际值与理论值不相符。另外,正常胚胎率与正常配子率也不一致。本文对染色体结构异常(相互易位、罗伯逊易位、倒位、染色体复杂性重组)和数目异常(性染色体数目异常、常染色体数目异常)男性的正常精子率以及正常胚胎率进行综述。     

Chromosome 21 Detection in Human Oocyte Fluorescence In Situ Hybridization: Possible Effect of Maternal Age

Purpose: The purpose of this study was to evaluate, among 100 uncleaved oocytes, the incidence of numerical and structural chromosome 21 and X abnormalities and to analyze the influence of various factors, such as in vitro (IVF) indications, follicle stimulation protocols, and women's age. Methods: We investigated 150 uncleaved oocytes from 128 patients after an IVF attempt. After cytogenetic analysis (Giemsa) 100 oocytes (66%) were selected for fluorescence in situ hybridization (FISH). Fluorescent probes for human chromosomes X and 21 were used simultaneously according to standard procedures for their hybridization and detection. Results and Conclusions: We analyzed by the FISH protocol 100 metaphase II oocytes with 22 to 25 chromosomes. Our results demonstrate a high rate of disomy for chromosome 21 in human oocytes. Among them, eight were disomic (8%) and three were nullosomic (3%) for chromosome 21. Only one disomy of chromosome X was noted. The various indications of IVF and the different folliculogenesis stimulating protocols did not seem to influence the results but suggested a correlation between the maternal age and the aneuploidy rate of chromosome 21.     

荧光原位杂交技术在产科相关领域的应用

荧光原位杂交（fluorescence in situ hybridization,FISH）技术是20世纪80年代末在放射性原位杂交技术基础上发展起来的一种非放射性分子细胞遗传技术,其是分子生物学、细胞遗传学及免疫学技术相结合的产物。该技术已广泛应用于分子生物学、医学、细胞遗传学等诸多领域,在产科已用于胚胎植入前遗传学诊断、产前诊断、自然流产和胎儿先天性心脏病的研究。综述FISH技术在产科相关领域的应用。     

荧光原位杂交技术用于快速产前诊断临床评价

荧光原位杂交技术（FISH）能有效检测出间期羊水或绒毛细胞的非整倍体异常,因此可以针对13,18,21,X和Y5种染色体进行产前诊断,在24～48h内得出结果。随着可靠的商业化的探针出现,FISH检测的效能和稳定性提高．假阳性率和假阴性率明显减少。但是,仍需警惕母源细胞污染对FISH结果的干扰。与核型分析相比,FISH技术的突出优势在于快速得到结果,从而更早缓解妊娠妇女的焦虑情绪。联合超声检查。FISH技术能在一站式快速产前诊断模式中发挥重要作用。     

Rapid Trisomy Diagnosis (21, 18, and 13) Using Fluorescent PCR and Short Tandem Repeats: Applications for Prenatal Diagnosis and Preimplantation Genetic Diagnosis

Purpose and Methods: Prenatal diagnosis of fetal trisomies is usually performed by cytogenetic analysis from amniotic fluid. This requires lengthy laboratory procedures and high costs and is unsuitable for large-scale screening of pregnant women. An alternative method, which is rapid and inexpensive and may potentially be suitable for diagnosing trisomies even from single fetal cells, is the fluorescent polymerase chain reaction (F-PCR) using polymorphic small tandem repeats (STRs). Results: In this paper we present data demonstrating that fluorescent PCR amplification of STRs can be used for rapid diagnosis of trisomy 21, trisomy 18, and trisomy 13 and can be successfully applied to both prenatal diagnosis and diagnosis of single cells. This study also reports significant numbers of prenatal diagnoses using quantitative fluorescent PCR. Conclusions: We believe that further studies of greater numbers of samples will determine the absolute reliability of this technique. These results also provide a model for trisomy diagnosis from single cells using multiple STR markers for either preimplantation genetic diagnosis or, potentially, diagnosis from fetal cells isolated from maternal blood.     

FISH快速检测自然流产绒毛染色体非整倍体异常的临床价值

目的:探讨应用荧光原位杂交技术(FISH)对早期自然流产绒毛染色体非整倍体检测的临床价值。方法:对30例因自然流产行清宫术的绒毛组织行FISH分析,使用7种探针对13、16、18、21、22号和X、Y染色体进行了检测,并对这30例流产夫妇行外周血淋巴细胞染色体常规核型分析。结果:FISH分析的30例自然流产的绒毛组织中,有17例检测出了异常信号,检出率为57%,其中8例16-三体、2例22-三体、2例13-三体和5例三倍体。30例自然流产夫妇外周血淋巴细胞染色体核型未见异常。结论:FISH技术可以快速、简便地检测出流产物绒毛组织染色体非整倍体的异常,FISH技术的应用可以为自然流产夫妇遗传咨询提供重要的信息。     

Spectral Imaging in Preconception/Preimplantation Genetic Diagnosis of Aneuploidy: Multicolor, Multichromosome Screening of Single Cells

Purpose: Our purpose was to evaluate the utility of spectral imaging for multicolor, multichromosome enumeration in human interphase cell nuclei. Methods: Chromosome-specific probes labeled with different fluorochromes or nonfluorescent haptens were obtained commercially or prepared in-house. Metaphase spreads, interphase lymphocytes, or blastomeres cells were hybridized with either 7 or 11 distinctly different probes. Following 46 hr of hybridization, slides were washed and detected using either a filter-based quantitative image processing system (QUIPS) developed in-house or a commercial spectral imaging system. Results: The filter-based fluorescence microscope system is preferred for simultaneous detection of up to seven chromosome targets because of its high sensitivity and speed. However, this approach may not be applicable to interphase cells when 11 or more targets need to be discriminated. Interferometer-based spectral imaging with a spectral resolution of approximately 10 nm allows labeling of chromosome-specific DNA probes with fluorochromes having greatly overlapping emission spectra. This leads to increases in the number of fluorochromes or fluorochrome combinations available to score unambiguously chromosomes in interphase nuclei. Conclusions: Spectral imaging provides a significant improvement over conventional filter-based microscope systems for enumeration of multiple chromosomes in interphase nuclei, although further technical development is necessary in its application to embryonic blastomeres. When applied to preconception/preimplantation genetic diagnosis, presently available probes for spectral imaging are expected to detect abnormalities responsible for 70–80% of spontaneous abortions caused by chromosomal trisomies.     

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。     

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     

Comparison of FISH, PRINS, and Conventional and Fluorescent PCR for Single-Cell Sexing: Suitability for Preimplantation Genetic Diagnosis

Purpose: Although conventional polymerase chain reaction (PCR) was the first method used for sexing in preimplantation genetic diagnosis, fluorescent in situ hybridization (FISH) has become the method of choice. Recently two new techniques, primed in situ synthesis (PRINS) and fluorescent PCR, have been developed. This study compares the reliability and accuracy of these four techniques in single cells. Results: In buccal cells, fluorescent PCR and FISH had similar reliability (94 and 93%) and accuracy (97 and 96%) rates. The reliability and accuracy of PRINS (91 and 25%) and conventional PCR (79 and 89%) were lower. In human blastomeres, FISH and flourescent PCR had similar reliability (100%, 717; 95%, 190/201) rates. Accuracy rates were 71% (5/7) and 99% (188/190) for FISH and fluorescent PCR, respectively, however, too few blastomeres were analyzed by FISH for meaningful comparison. However, when these data are compared with published data, the method of choice for blastomere sexing appears to be fluorescent PCR. Conclusions: Flouroscent PCR has major implications for PGD.     

Pre-implantation Genetic Diagnosis

Pre-implantation genetic diagnosis is now available in more than 20 countries with over 700 cycles completed and more than 100 normal babies born. A review of pre-implantation genetic diagnosis is presented in which the technology, types of diagnoses possible, problems to be surmounted, and ethical issues are discussed.     

Assessing the Chromosome Copy Number in Metaphase II Oocytes by Sequential Fluorescence in Situ Hybridization

Purpose: Aneuploidy in oocytes is the main cause of failed embryo implantation and of miscarriage. At present, only limited data on the prevalence of aneuploidy in freshly collected human oocytes are available and all studies have been performed with conventional methods for karyotyping. In this feasibility study, multiple-hybridization fluorescence in situ hybridization (FISH) was evaluated as an alternative method to determine the number of chromosomes in oocytes. Methods: Fifty-two spare oocytes were collected from 23 patients treated with gonadotropins for intrauterine insemination or intracytoplasmic sperm injection. A conventional dual color FISH approach using mixtures of chromosome-specific standard alpha-satellite probes was applied consecutively to the chromosomes of the same metaphase II oocyte. Mixtures of three to six probes were designed in order to allow chromosome identification based on signal color and centromeric index. Results: One hybridization cycle was possible in 52 uninseminated metaphase II oocytes, two hybridizations in 43 oocytes (82.7%), three hybridizations in 30 oocytes (57.6%), four hybridizations in 27 oocytes (51.9%), and five hybridizations in 15 oocytes (28.8%). Altogether, 591 chromosomes could be marked (47.4% of the entire chromosome complement, 11.4 chromosomes per oocyte). The most important single factor contributing to technical failure was loss of the oocyte from the slide. Conclusions: This feasibility study demonstrates that multiple-hybridization FISH can be used for the assessment of a larger proportion of the chromosome complement in oocyte as compared to previous studies based on FISH.