FISH技术在检测自然流产绒毛组织非整倍体异常中的应用研究

目的:探讨运用荧光原位杂交(FISH)检测自然流产绒毛组织的临床价值,评价它与传统经典的核型分析方法的关系。方法:对157例孕早期自然流产的绒毛组织进行FISH检测,均采用16、22、13、21、18、X、Y号染色体荧光探针检测,判断染色体非整倍体异常情况。同时进行绒毛细胞培养染色体核型分析,作为对照诊断标准。结果:核型分析成功率为48.4%,FISH检测成功率为100%。核型分析成功的76例样本中,64例结果与核型分析结果相一致,以细胞遗传学作为诊断标准,诊断的符合率为84.2%。结论:FISH技术与传统的绒毛细胞培养染色体核型分析相比,过程迅速,方法简单,提高了诊断的成功率,但无法完全取代传统的染色体核型分析,应两者结合应用于临床。     

荧光原位杂交技术在自然流产绒毛染色体核型检测中的应用

目的 探讨荧光原位杂交(fluorescence in situ hybridization,FISH)技术在提高自然流产绒毛染色体核型分析准确性和异常核型检出率中的作用.方法 采用18、X、Y染色体着丝粒探针和13、21及16、22染色体单一序列探针,对100例自然流产绒毛标本同时进行FISH检测和常规染色体核型分析,比较并分析2种方法的一致性及差异.结果 (1)染色体核型分析:100例流产绒毛标本培养成功率为89.0％(89/100).检出异常核型51例,异常核型检出率为57.3％(51/89),其中常染色体非整倍体37例、性染色体非整倍体4例、三倍体2例、四倍体1例,还有1例核型为68,XX,结构异常6例.(2) FISH技术检测:100例流产绒毛标本均获得FISH结果,成功率为100.0％.共检出38例染色体异常,异常核型检出率为38.0％(38/100),其中常染色体非整倍体25例、性染色体非整倍体5例、三倍体3例,还有1例13、16、18、21、22号染色体均为三倍体,嵌合体4例.(3)核型分析与FISH结果的异同:在绒毛标本培养失败的11例中,FISH检测出染色体异常2例,占18.2％(2/11);核型为46,XY者中FISH检测出3例非整倍体嵌合体;核型为46,XX者中FISH检测出染色体异常2例.FISH能检测出的染色体异常占所有染色体异常核型的65.5％(38/58).结论 FISH技术能简便、快速的检测自然流产绒毛染色体非整倍体数目异常,联合常规染色体核型分析能提高染色体核型分析的准确性和异常核型的检出率.     

两种不同遗传学分析方法用于诊断自然流产组织的比较

目的探讨比较基因组杂交（CGH）技术与绒毛细胞培养染色体核型分析用于自然流产组织遗传学诊断的准确性。方法选择妊娠49—91d的自然流产患者38例,在无菌条件下经宫颈取绒毛,其中难免流产的新鲜组织标本27份,过期流产的陈旧组织标本11份。每份组织标本均采用绒毛细胞培养染色体核型分析,并同时采用CGH技术对全基因组进行分析。结果CGH技术诊断成功率为100％（38／38）,而绒毛细胞培养染色体核型分析诊断成功率为82％（31／38）。两种方法的诊断符合率为90％（28／31）,在3例出现不同诊断结果的病例中,1例绒毛细胞培养染色体核型分析显示染色体核型正常,而CGH技术显示3q^22_q^24缺失;另2例绒毛细胞培养染色体核型分析为3倍体,但CGH技术诊断结果显示正常。在7例绒毛细胞培养失败而仅有CGH技术诊断结果者中,3例为染色体非整倍体异常,另4例正常。结论CGH技术用于诊断自然流产组织是可行的。绒毛细胞培养染色体核型分析比较,CGH技术诊断成功率高,且对非平衡染色体结构重排的诊断有较高的敏感性,可以作为绒毛细胞培养染色体核型分析的补充方法。     

早期自然流产绒毛组织SNP-array遗传学诊断研究

目的:初步探讨单核苷酸多态性阵列(SNP-array)在早期流产绒毛遗传学诊断中的临床应用价值。方法:选取临床诊断为早期自然流产的82例患者,刮宫术后获取绒毛组织,行常规绒毛细胞培养G显带核型分析,并同时提取绒毛组织DNA进行SNP-array检测,比较两者的检测结果。结果:常规绒毛细胞培养G显带核型诊断成功率87.8%(72/82),SNP-array诊断成功率为100%(82/82)。G显带分析获得结果 72例,核型正常35例,核型异常37例,异常率51.4%(37/72)。82例SNP-array分析结果中,核型正常30例,核型异常52例,异常率63.4%(52/82)。G显带分析失败的10例标本中,SNP-array检出6例异常;G显带与SNP-array结果不符的12例中,包括2例全基因组单亲二倍体(uniparental disomy,UPD),2例是部分染色体UPD。结论:SNP-array技术具有高准确性、高通量、快速检测等优点,在自然流产绒毛遗传学分析中具有较强的临床应用价值。     

多重连接依赖探针扩增技术在稽留流产绒毛组织染色体核型分析中的应用

目的 探讨多重连接依赖探针扩增(MLPA)技术在稽留流产绒毛组织染色体核型分析中的应用.方法 选择2008年2-10月于深圳市妇幼保健院就诊,经激素水平测定、B超和临床检查确诊为稽留流产患者91例为病例组;随机抽样方法选择同期20例经激素水平测定、B超和临床检查为正常妊娠,要求人工流产者为对照组.人工流产术中无菌条件下获取两组妇女的绒毛组织,培养后每份样本分别采用传统细胞遗传学G显带染色体核型分析方法、同时提取DNA采用MLPA技术分析染色体异常,并与传统染色体核型分析结果进行比较.结果 91例病例组样本中,有84例(92%)采用MLPA技术进行染色体核型分析的非整倍体结果与传统染色体核型分析方法的结果一致,其中包括正常核型40例、常染色体三体29例、常染色体双三体1例、X染色体单体合并常染色体三体1例、X染色体单体10例、嵌合性X染色体单体2例和1例结构异常46,XX,der(5)t(5;8)(p1.2;q1.2);其余结果不一致的7例中,采用传统染色体核型分析方法检测出2例三倍体和5例四倍体,而采用MLPA技术检测结果均为正常的二倍体.20例对照组样本两种技术的分析结果均一致.结论 MLPA技术分析染色体非整倍体异常是一种简单、快速且有效的方法,具有临床实际应用价值.     

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。     

985例早孕期线毛活检样本的遗传学结果分析

目的探讨早孕期绒毛活检(chorionic villus sampling,CVS)术在产前诊断中的应用价值及安全性。方法回顾性分析2012年1月至2017年12月在北京大学第一医院妇产科行CVS术取材,并通过染色体核型分析和荧光原位杂交(fluorescence in situ hybridization,FISH)进行产前诊断的985例的病历资料,对细胞培养成功率、产前诊断指征、细胞遗传学诊断结果和CVS手术并发症等进行描述性分析。结果985例中,970例(98.48%)行FISH检测,893例(90.66%)进行了染色体核型分析,878例(89.14%)同时行核型分析与FISH检测。CVS术取材后,细胞培养成功率为96.64%(863/893)。超声异常是最常见的产前诊断指征,占42.64%(420/985)。本研究共检出各类染色体异常181例,检出率为18.38%(181/985)。其中,超声异常为指征的检出率最高,为31.90%(134/420),其次为不良孕产史[11.83%(20/169)]和高龄[8.21%(11/134)]。此外,有16例可能因胎盘嵌合和13例可能因母体污染而引起的FISH检测与核型分析结果不符的病例。CVS术后4周内,6例(0.61%,6/985)孕妇发生胎停育(其中4例存在染色体数目异常);其余979例(99.39%)未见近、远期手术并发症。结论早孕期CVS术是一种安全可靠的介入性诊断方式,对于早孕期超声异常等特定指征人群可以更早获得产前诊断结果,增强产前诊断的针对性,提高效率,但也不可忽视胎盘嵌合和母体污染对诊断结果可能造成的影响。     

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。     

不同年龄和流产次数的复发性流产患者绒毛染色体核型分析

目的:了解复发性自然流产胚胎染色体异常发生情况。方法:2008年1月至2011年12月,在我院诊治并成功行绒毛染色体核型分析的自然流产患者235例,根据自然流产次数分为复发性流产组(125例)和偶发性流产组(110例)。比较两组绒毛染色体异常发生率和类型的差异,不同流产次数的胚胎染色体异常发生情况,以及不同年龄患者绒毛染色体异常的发生情况。结果:复发性流产组,绒毛染色体异常发生率显著低于偶发性自然流产组(47.2%vs 70.9%,P<0.05)。复发性流产组中三体占异常染色体的66.1%(39/59),显著高于偶发性流产组(44.8%,35/78)(P<0.05)。随着自然流产次数的增加,绒毛染色体异常发生率降低,差异有统计学意义(χ2=15.266,P=0.004)。复发性流产组中,年龄≥35岁者的绒毛染色体异常发生率明显高于年龄<35岁者(60.9%vs39.2%,P<0.05)。偶发性自然流产组中,年龄≥35岁者的绒毛染色体异常发生率亦明显高于年龄<35岁者(88.9%vs 62.2%,P<0.05)。结论:胚胎染色体异常是引起复发性流产的一个重要原因,随着流产次数的增加,流产胚胎染色体异常的发生率降低。无论是复发性流产还是偶发性流产,高龄均是引起胚胎染色体异常的高危因素。     

自然流产绒毛染色体核型分析的研究现状

自然流产的发病率日趋升高,其主要原因为染色体异常,分析胚胎染色体的核型对寻找自然流产的原因具有重要意义。绒毛细胞染色体制片的培养法成功率高于直接法,但培养法的操作难度及成本亦高于直接法;自然流产的绒毛染色体异常核型中以非整倍体的发生最多见,其中16三体约占三体的1/3;自然流产、辅助妊娠后流产的绒毛染色体异常率分别都高于人工流产的绒毛染色体异常率;对于自然流产绒毛染色体异常与支原体、衣原体感染相关性及自然流产次数、年龄、孕周及胚胎性别与绒毛染色体核型的关系均尚无明确结论。目前类似以上通过绒毛染色体分析寻找自然流产原因的研究很多,但可以治疗的原因并不多见,故还需结合临床的实验指标,寻找与绒毛染色体的相关性,进一步提高染色体分析的意义。     

(Potential) false-negative diagnoses in chorionic villi and a review of the literature

OBJECTIVES: To assess the incidence of (potential) false-negative findings of cytogenetic diagnosis in STC-villi and/or LTC-villi and to determine the best strategy for karyotyping chorionic villi in order to avoid false-negative results. METHODS: 2476 chorionic villus samples were received for prenatal cytogenetic investigations. Karyotyping was routinely performed on STC- and LTC-villi preparations by G-banding. Fluorescence in situ hybridization (FISH) analyses were performed in addition to standard chromosome analysis when necessary. Sometimes follow-up investigations like amniocentesis were performed before a definite prenatal cytogenetic result could be reported. RESULTS: In 2389/2476 (96.5%) of the cases, both STC- and LTC-villi were investigated. Normal STC- with abnormal LTC-villi results and finally an abnormal fetal karyotype were detected in ten cases (10/2389; 0.42%); in 9/10 of the cases the indication was fetal ultrasound abnormalities. Normal STC- and LTC-villi and finally an abnormal fetal karyotype were detected in two cases (2/2389; 0.08%). CONCLUSION: The most reliable technique for prenatal diagnosis after chorionic villus sampling (CVS) is the combination of the analysis of both STC- and LTC-villi to reduce the incidence of false-negative findings to a minimum. In the case of fetal ultrasound abnormalities with a small amount of villi available, the investigation of LTC-villi is recommended over that of STC-villi.     

Chorionic villus sampling (CVS) and fluorescence in situ hybridization (FISH) for a rapid first-trimester prenatal diagnosis

OBJECTIVES: Early diagnosis of unbalanced chromosomal abnormalities can be crucial in minimizing the trauma caused by an elective abortion. Chorionic villus sampling (CVS) can be performed from 9 weeks of gestation. However, two major problems are encountered in fetal karyotyping using cultured cells from chorionic villi: the relatively slow growth of these cells in culture, which delays the diagnosis, and the occurrence of maternal cell contamination (MCC). With FISH, a result can be obtained within 24 h, and, as no cell culturing is involved, the problem of MCC is minimized. METHODS: Thirty-two women undergoing CVS between 9 and 12 weeks of gestation were offered FISH analysis in addition to the standard chromosome analysis. RESULTS: FISH was informative in all of the cases tested. Eleven aneuploidies were detected in cases of hygroma or abnormal nuchal translucency and two out of four fetuses from parental translocation were unbalanced. The decision to perform early termination of these chromosomally abnormal pregnancies was based on FISH results and ultrasound abnormalities, without waiting for karyotype results. CONCLUSION: The present study confirms that the association of FISH and CVS allows a rapid and early prenatal diagnosis, and emphasizes that this association is of great benefit in cases of known parental balanced translocation or when hygroma is detected by ultrasonography.     

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.     

Puncture of the chorionic villi. Technic--experiences--risks

Chorion villi biopsy is a recently introduced method for first trimester prenatal diagnosis. Based on 435 cases of chorionic villi biopsies, obtained during a 3 year period, we report our experiences with the technique of chorionic villi sampling, chromosomal analysis from trophoblast tissue and possibly associated complications, such as spontaneous abortions, vaginal bleeding, and chromosomal mosaicism. The rate of spontaneous abortions in our group of patients was 3%. This appears low, considering the high overall spontaneous abortion rate in early pregnancy of women over 35 years. The cytogenetic diagnosis is complicated by a high rate (2.8%) of chromosomal mosaicism, which were found to be not representative for the fetus, but required control amniocentesis. From our experiences with this method we conclude that chorion villi biopsy can be offered as a reliable alternative method to amniocentesis in the hands of an experienced team of obstetric surgeons and cytogenetists.     

Is cytogenetic diagnosis of 46,XX karyotype spontaneous abortion specimens erroneous? Fluorescence in situ hybridization as a confirmatory technique

AIM: Performing the standard cytogenetic technique on spontaneous abortion material is still a valuable tool, but finding a normal 46,XX karyotype can confuse investigators and lead to a problem in diagnosis. This is mainly because it is possible for the female or male conceptus to retain contaminating maternal cells. To address this possibility, we used fluorescence in situ hybridization technique (FISH). X (DXZ1: p11.1-q11.1 region) and Y (DYZ3: p11.1-q11.1 region) chromosome alpha-satellite probes were employed to confirm the karyotypes previously diagnosed as 46,XX by our cytogenetic laboratory, or to verify the occurrence of 'Y chromosome component'. METHODS: Besides conventional long-term tissue cultures and G-bands by trypsin using Giemsa (GTG) bandings, FISH analyses were also performed. RESULTS: A total of 134 spontaneous abortion specimens (singleton gestations) were referred for cytogenetic evaluation, of which 125 specimens were successfully karyotyped. Of these, 20.8% (26/125) had chromosome aberrations; 88.5% (23/26) of these aberrations were numerical and 11.5% (3/26) were structural. The most prevalent numerical anomalies were trisomies 15, 16 and 21, tetraploidies, triploidies and monosomy X. FISH results were obtained for 45 out of 92 cases with 46,XX, of which 2 (4.4%) showed XY signals. CONCLUSIONS: For accurate cytogenetic evaluation of spontaneous abortion materials, an additional technique such as FISH is required in order to confirm the cytogenetic results or to provide an estimate of the error rate in the analysis of miscarriages.     

First-trimester prenatal diagnosis performed on pregnant women with fetal ultrasound abnormalities: The reliability of interphase fluorescence in situ hybridization (FISH) on mesenchymal core for the main aneuploidies

Objectives

To examine the reliability of interphase FISH analysis of the main aneuploidies performed on mesenchymal core when prenatal diagnosis was performed on pregnant women with first-trimester fetal abnormalities on ultrasound.

Study design

386 first-trimester prenatal examinations were investigated from chorionic villus samplings for increased nuchal translucencies or other fetal ultrasound abnormalities. Interphase fluorescence in situ hybridization (FISH) for the main aneuploidies (trisomies 13, 18, 21 and gonosomal aneuploidies) was performed on the mesenchymal core of villi. Molecular cytogenetic results were always complemented by conventional cytogenetic results on long-term cultured villi (LTC-villi). Short-term cultured villi (STC-villi) preparations were retrospectively performed only when a chromosomal abnormality was observed with interphase FISH and/or LTC-villi.

Results

88 chromosomal abnormalities (88/386 = 22.8% of first-trimester diagnoses) which could discuss subsequent abortions were observed after LTC-villi preparations. All cases possibly detectable by interphase FISH were detected. Thus, 85 aneuploidies (85/386 = 22.0% of first-trimester diagnoses; 85/88 = 96.6% of chromosomal abnormalities) were detected by interphase FISH, allowing early abortion by curettage before week 14 amenorrhea. No discrepancy occurred between interphase FISH and LTC-villi results for the aneuploidies studied. Three false-negative results (3/386 = 0.77% of first-trimester diagnoses; 3/88 = 3.41% of chromosomal abnormalities) were observed with STC-villi.

Conclusion

We observed a high rate of false-negative results on cytotrophoblast cells. Conversely, interphase FISH of the main aneuploidies on the mesenchymal core provided rapid and reliable results, and therefore should be preferred to STC-villi in first-trimester prenatal diagnosis performed on pregnant women with fetal abnormalities on ultrasound.