羊膜腔穿刺术的临床应用

羊膜腔穿刺术 (ａｍｎｉｏｃｅｎｔｅｓｉｓ)现已成为围产医学临床上不可缺少的一种手段 ,应用范围越来越广 ,本文仅就羊膜腔穿刺术在围产医学中的应用作一简述。1　先天异常的羊水诊断1 1　胎儿染色体疾病的诊断　于孕 16～ 2 0周作羊膜腔穿刺抽取羊水 ,通过羊水细胞培养作羊水细胞染色体分析。可用于常染色体异常、各种三体综合征、性染色体异常和Ｘ性连锁遗传病携带者的胎儿性别鉴定。近年发展起来的荧光原位杂交 (ＦＩＳＨ)技术 ,未培养的羊水细胞ＦＩＳＨ能快速(16小时内 )诊断羊水细胞染色体数目异常。羊水细胞染色体ＦＩＳＨ能对微小…     

多色探针荧光原位杂交技术用于诊断羊水细胞染色体异常

应用羊水细胞进行产前诊断 ,已广泛应用于临床。用间期细胞行原位杂交是检测染色体异常的新技术[1] 。我们应用双色Ｘ/Ｙ计数探针 ,多色Ｘ/Ｙ、13、18、2 1探针荧光原位杂交 (ｆｌｕｏｒｅｓｃｅｎｃｅｉｎｓｉｔｕｈｙｂｒｉｄｉｚａｔｉｏｎ ,ＦＩＳＨ)技术 ,对妊娠 12～ 2 2周孕妇行羊膜腔穿刺抽取羊水细胞 ,诊断染色体非整倍体和胎儿性别 ,现将结果报道如下。一、资料与方法1.资料来源 :选择 1998～ 2 0 0 0年在我院因分娩过畸形儿 ,要求行产前诊断或引产的孕妇 2 5例 ,孕周 12～ 2 1周 ,年龄 2 5～ 35岁。按不同孕周分为 5组 ,每两周为…     

荧光原位杂交技术在细胞遗传学中的应用

目的：探讨荧光原位杂交技术（ＦＩＳＨ）在细胞遗传学异常染色休核型分析中的应用价值。方法：应用Ｘ，Ｙ，１３／２１，１８号染色体α卫星ＤＮＡ探针（包括生物素标记及地高辛标记的探针，）对原Ｇ带核型为４６，ＸＯ＋ｒ？）；４６，ＸＯ＋ｉ（Ｘｐ）９７％／４７，ＸＯ＋２ｉ（Ｘｐ）３％；４７．ＸＸＸ／４５，ＸＯ；４７，ＸＹ＋２１等４例的外周血染色体及间期细胞进行原位杂交，并用正常男、女核型作为阳性对照，以不加探针的杂液反应为阴性对照，杂交后用ＯｌｙｍｐｕｓＢＸ６０荧光显微镜观察玻片并照像。结果：原Ｇ带核型４７，ＸＹ＋２１；４７，ＸＸＸ／４５，ＸＯ与ＦＩＳＨ结果一致，分别诊断为先天性愚型及Ｔｕｒｎｅｒ综合征。原Ｇ带核型４６，ＸＯ＋ｒ？的ｒ是征，其真正核型是４６，ＸＯ＋ｄｉｃ（Ｙｑ）／４７，ＸＯ＋２［ｄｉｃ，ｉ（Ｙｑ）］。正确诊断为Ｙ染色体结构异常与性腺发育不全综合征。结论：对一些常规Ｇ带难以确诊的复杂染色体结构畸变核型。如环状、易位等，ＦＩＳＨ技术具有非常重要的效用。     

应用荧光光谱技术诊断胎粪吸入综合征

应用荧光光谱技术对１７例胎粪吸入综合征（ＭＡＳ，ＭＡＳ组）、２４例羊水混浊而非胎粪吸入综合征（羊水混浊组）及２７例羊水澄清的正常新生儿（羊水澄清组）生后２４时内尿液进行测定。并应用荧光强度计算出各组尿荧光胎粪指数（ＵＦＭＩ），并与尿胎粪指数（ＵＭＩ）进行比较。结果：ＭＡＳ组新生儿尿液具有特异性荧光光谱改变；与含锌粪卟啉荧光光谱相似，而正常新生儿尿液及澄清羊水的荧光光谱与粪卟啉相似。ＭＡＳ组的ＵＦＭＩ值明显高于其它两组，尤其与羊水澄清组比较，差异有极显著性（Ｐ＜０．００１）。ＵＦＭＩ与ＵＭＩ用于诊断ＭＡＳ的敏感性分别为１００％、５１％；特异性为９７％、４８％；准确性为９０％、５２％。提示：ＵＦＭＩ用于诊断胎粪吸入综合征更准确、简便。     

胎儿染色体核型异常3例报道

为了降低围生儿死亡率 ,减少出生缺陷儿的发生 ,我们自 2 0 0 0年 11月 1日至 2 0 0 1年 7月 3 1日对沈阳市九区的6664例妊娠 14～ 2 0周的孕妇进行了产前胎儿核型异常的筛查。经外周血监测ＡＦＰ、ＦＲＥＥ β ＨＣＧ疑有胎儿核型异常的高危孕妇共 417例 ,在医生的建议下 ,有 10 0例夫妇同意羊膜腔穿刺抽取羊水进一步确诊 ,经羊水细胞培养及荧光原位杂交 (ＦＩＳＨ)进行胎儿染色体核型分析 ,诊断胎儿异常有 3例。分别为 18三体 2例 ,克氏症 1例 ,均已行治疗性流产。现将 3例胎儿染色体核型异常报道如下。例 1.孕妇 3 3岁 ,孕 3产 0 ,非近亲…     

染色体病的植入前诊断

染色体病是一大类遗传病 ,由染色体的数目异常或结构异常所致 ,已发现的染色体病已超过 10 0 0种。现在 ,还没有有效的方法治疗此类疾病。通过羊膜腔穿刺 (ａｍｎｉｏｃｅｎｔｅｓｉｓ,ＡＣ)及绒毛膜取样 (ｃｈｏｒｉｏｎｉｃｖｉｌｌｉｓａｍｐｌｉｎｇ ,ＣＶＳ)技术获取孕中期羊水中胎儿细胞或孕早期绒毛膜滋养细胞 ,以细胞遗传学技术及荧光原位杂交 (ｆｌｕｏｒｅｓｃｅｎｔｉｎｓｉｔｕｈｙｂｒｉｄｉｚａｔｉｏｎ ,ＦＩＳＨ)技术分析胚胎的染色体组成 ,筛除异常胚胎 ,使正常胚胎继续妊娠 ,有效地减少了染色体病患儿的出生。但是传统的…     

胎儿幼稚红细胞产前遗传学诊断的研究

目的：探讨利用早期孕妇血中胎儿幼稚红细胞，进行无创伤性胎儿染色体异常产前诊断的可行性。方法：对１３例孕早期（８～１４周）已知孕男性胎儿孕妇外周血中糖蛋白Ａ（ＧＰＡ）表达阳性的细胞，进行荧光激活细胞分离（ＦＡＣＳ）及Ｙ染色体特异的引物介导原位标记（ＰＲＩＮＳ）检测，同时在测定４１例正常孕妇孕早期（８～１４周）血清妊娠相关血浆蛋白Ａ（ＰＡＰＰ┐Ａ）作为正常参考值的基础上，对５例可疑孕Ｄｏｗｎ′ｓ综合征胚胎的高龄孕妇进行ＰＡＰＰ┐Ａ检测、ＧＰＡ阳性细胞的ＦＡＣＳ及２１号染色体ＰＲＩＮＳ检测。结果：１３例孕男性胎儿的孕妇血ＧＰＡ阳性细胞中，胎儿幼稚红细胞的平均含量达到１４．５％；５例高龄孕妇血清ＰＡＰＰ┐Ａ均在正常范围内，ＧＰＡ阳性细胞中胎儿幼稚红细胞的２１号染色体ＰＲＩＮＳ检测未见异常。结论：早期孕妇血中存在胎儿幼稚红细胞，并可利用这些细胞对胎儿染色体非整倍性异常进行产前分子┐细胞遗传学诊断。     

STR-PCR在产前诊断胎儿唐氏综合征中的应用

目的:研究通过多重荧光定量PCR诊断胎儿染色体非整倍体用于临床快速产前诊断的可行性。方法:从孕中期羊水中提取胎儿DNA,通过多重荧光定量PCR使用STR对13、18、21号染色体进行非整倍体筛查,筛查结果异常者再进行快速诊断。用PCR诊断的羊水标本同时使用"金标准"染色体核型分析法做对比。结果:34例羊水标本中2例标本由于母血污染严重未行PCR检测,1例标本经PCR及核型分析均失败,29例标本经PCR和核型分析诊断为正常染色体,2例标本经PCR和核型分析诊断为21-三体。结论:通过STR-PCR法使用多重荧光酶联聚合反应探针产前诊断胎儿唐氏综合征是临床快速产前诊断的有效方法之一。     

羊水在产前诊断中的作用

羊水穿刺术 (以下简称羊穿 )是最常用的有损性产前诊断技术 ,早在 2 0世纪 5 0年代就应用于胎儿性别鉴定和胎儿Ｒｈ溶血性疾病的诊断 ,196 6年Ｓｔｅｅｌ、Ｂｅｒｇ和Ｔｈｉｅｄｅ成功地进行了羊水细胞的培养和胎儿核型分析后 ,羊穿被广泛地应用于胎儿染色体异常和代谢病的产前诊断。近年来随着科技的不断进步 ,羊水在产前诊断中发挥了越来越大的作用。1　胎儿畸形的诊断1 1　羊水ＡＦＰ (ａｌｐｈａ -ｆｅｔｏｐｒｏｔｅｉｎ ,甲胎蛋白 )和ＡｃｈＥ(ａｃｅｔｙｃｈｏｌｉｎｅｓｔｅｒａｓｅ ,乙酰胆碱酯酶 )含量的测定　　ＡＦＰ主要是由胎…     

宫腔内人工授精中两种不同促排卵方案治疗不孕症的疗效比较

促卵泡刺激素（ＦＳＨ）联合宫腔内人工授精（ＩＵＩ）比克罗米芬（ＣＣ）加ＩＵＩ的疗效好［１］,但ＦＳＨ价格较贵,发生卵巢过度刺激综合征（ＯＨＳＳ）的机会较多。本文的目的在于观测ＩＵＩ治疗中,ＣＣ加ＦＳＨ能否使ＦＳＨ用量减少而妊娠率增加,以寻找合理的治疗...     

Rapid positive confirmation of mosaicism for a small supernumerary marker chromosome as r(8) by interphase fluorescence in situ hybridization,quantitative fluorescent polymerase chain reaction,and array comparative genomic hybridization on uncultured amniocytes in a pregnancy with fetal pyelectasis

ObjectiveThis study aimed at presenting prenatal diagnosis and molecular cytogenetic characterization of a small supernumerary marker chromosome (sSMC) derived from chromosome 8 by fluorescence in situ hybridization (FISH), quantitative fluorescent polymerase chain reaction (QF-PCR), and array comparative genomic hybridization (aCGH) on uncultured amniocytes.Materials, Methods, and ResultsA 32-year-old woman underwent amniocentesis at 19 weeks of gestation because of fetal pyelectasis. Amniocentesis revealed a de novo ring-shaped sSMC in two of 21 colonies of cultured amniocytes. Repeated amniocentesis at 22 weeks of gestation revealed a karyotype of 47,XY,+mar[8]/46,XY[32] in cultured amniocytes. Spectral karyotyping and FISH confirmed that the sSMC was derived from chromosome 8. She underwent a third amniocentesis at 26 weeks of gestation. Oligonucleotide-based aCGH analysis on uncultured amniocytes demonstrated a 43 Mb genomic gain in chromosome 8 encompassing 8p22→q12.1. Polymorphic DNA marker analysis of the uncultured amniocytes revealed a maternal origin of the sSMC and excluded uniparental disomy 8. Interphase FISH analysis showed three D8Z2 signals in 8/40 (20%) of uncultured amniocytes. The cultured amniocytes had a karyotype of 47,XY,+r(8)(p22q12.1)[3]/46,XY[37]. The pregnancy was carried to term, and an apparently normal baby, weighing 3300 g, was delivered with mild hydronephrosis but no other phenotypic abnormalities. The cord blood was found to have a karyotype of 47,XY,+r(8)(p22q12.1)[2]/46,XY[38].ConclusionPrenatal diagnosis of fetal pyelectasis should alert obstetricians of chromosome aberration. Interphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes are helpful in rapid positive confirmation of an sSMC detected at amniocentesis.     

Mosaic isochromosome 20q at amniocentesis: Prenatal diagnosis,genetic counseling and literature review

ObjectiveWe present prenatal diagnosis of mosaic isochromosome 20q [i(20q)] at amniocentesis, and we review the literature.Case reportA 36-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Amniocentesis revealed a karyotype of 46,XY,i(20)(q10)[27]/46,XY[29]. Prenatal ultrasound findings were unremarkable. The parental karyotypes were normal. Repeat amniocentesis was performed at 20 weeks of gestation. During repeat amniocentesis, array comparative genomic hybridization (aCGH), interphase fluorescence in situ hybridization (FISH) and quantitative fluorescent polymerase chain reaction (QF-PCR) assay were performed on uncultured amniocytes, and conventional cytogenetic analysis, interphase FISH and aCGH were performed on cultured amniocytes. In the repeat amniocentesis, the cultured amniocytes revealed a karyotype of 46,XY. Interphase FISH analysis showed the i(20q) signal in 5.2% (5/96) of the uncultured amniocytes compared with 2% in the control, and in 0.98% (1/102) of the cultured amniocytes compared with 2% in the control. aCGH detected no genomic imbalance in both uncultured and cultured amniocytes. QF-PCR analysis excluded uniparental disomy 20. At 38 weeks of gestation, a healthy 2870-g male baby was delivered with no phenotypic abnormality. The postnatal blood karyotype was 46,XY. FISH analysis on urinary cells showed 2.1% (2/95 cells) mosaicism compared with 1.9% (2/105 cells) in the control.ConclusionMosaic i(20q) at amniocentesis is a benign condition associated with a favorable outcome in most cases and can be a cell culture artifact confined to cultured amniocytes. Molecular cytogenetic analysis using uncultured amniocytes is useful for rapid confirmation. Prenatal diagnosis of very high percentage of mosaicism for i(20q) at amniocentesis should alert the presence of fetal structural abnormalities. Prenatal diagnosis of mosaic i(20q) at amniocentesis should include a detail examination of fetal brain and spine.     

Mosaic trisomy 2 at amniocentesis: Prenatal diagnosis and molecular genetic analysis

ObjectiveThis study aims at presenting prenatal diagnosis of mosaic trisomy 2 and reviewing the literature.Materials, Methods, and ResultsA 32-year-old woman underwent amniocentesis at 21 weeks of gestation because of abnormal maternal serum biochemistry. Amniocentesis revealed a karyotype of 47,XY,+2[1]/46,XY[21] in in situ cultures. The single colony with trisomy 2 had two metaphase cells, and both had the karyotype of 47,XY,+2. Repeated amniocentesis was performed at 23 weeks of gestation. Interphase fluorescence in situ hybridization (FISH) analysis on uncultured amniocytes using a 2q11.1-specific probe RP11-468G5 (spectrum green) showed three green signals in 11 of 47 uncultured amniocytes, indicating 23.4% mosaicism for trisomy 2. The cultured amniocytes had a karyotype of 46,XY[20 colonies]. Polymorphic DNA marker analysis excluded uniparental disomy 2. The woman underwent the third amniocentesis at 25 weeks of gestation. Interphase FISH analysis on uncultured amniocytes revealed 9.4% (5/53 cells) mosaicism for trisomy 2. The cultured amniocytes had a karyotype of 46,XY[30 colonies]. Prenatal ultrasound was normal. The parents decided to continue the pregnancy to term, and a 3316-g baby was delivered with no phenotypic abnormalities. Cord blood had a karyotype of 46,XY[40 cells]. Interphase FISH analysis on uncultured urinary cells revealed 8.2% (4/49 cells) mosaicism for trisomy 2. The neonate was normal in growth and psychomotor development at 6 months of age.ConclusionPrenatal diagnosis of a single colony with two or more cells with trisomy 2 at amniocentesis should alert a clinically significant aneuploidy, and interphase FISH on uncultured amniocytes is useful for rapid confirmation of low-level trisomy 2 mosaicism at amniocentesis. The abnormal cell line of trisomy 2 may disappear after long-term amniocyte cultures.     

Trisomy 7 mosaicism at amniocentesis: interphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes for rapid distinguishing of true mosaicism from pseudomosaicism

ObjectiveTo present prenatal diagnosis of true trisomy 7 mosaicism.Materials, Methods and ResultsA 36-year-old woman underwent amniocentesis at 18 weeks of gestation. Amniocentesis revealed a karyotype of 47,XY,+7[20]/46,XY[9]. The parental karyotypes were normal. Repeated amniocentesis was performed at 20 weeks of gestation. Array comparative genomic hybridization (aCGH) analysis on uncultured amniocytes manifested a genomic gain in chromosome 7. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on uncultured amniocytes showed a biparental diallelic pattern with a dosage increase in the maternal allele. Interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes revealed three 7q-specific signals in 13 of 50 (26%) of the cells. The cultured amniocytes had a karyotype of 47,XY,+7[12]/46,XY[14]. The ultrasound findings were unremarkable. The pregnancy was subsequently terminated, and a fetus was delivered with facial dysmorphisms. Postnatal tissue samplings revealed the mosaic trisomy 7 level of 37.5% (15/40), 30% (12/40), 42.5% (17/40), 82.5% (33/40), 52.5% (21/40), and 27.5% (11/40) in skin, liver, lungs, placenta, membrane, and cord, respectively. The cord blood had a karyotype of 46,XY. PEG1/MEST methylation-sensitive high-resolution melting PCR assay of cord blood showed no uniparental disomy for chromosome 7.ConclusionInterphase FISH, QF-PCR, and aCGH analyses on uncultured amniocytes are useful for rapid distinguishing of true mosaicism from pseudomosaicism for trisomy 7 at amniocentesis. Cord blood sampling for confirmation of fetal trisomy 7 mosaicism is not practical.     

Rapid detection of trisomy 21 by gene dosage analysis using quantitative real-time polymerase chain reaction

AIM: Rapid detection of fetal aneuploidy helps inform a mother's choice about the course of her pregnancy. Obtaining results by fluorescent in situ hybridization (FISH) requires more than 24 h, and thus a more rapid method is needed. METHODS: Conventional G-banding and FISH for chromosome 21 were performed for cultured amniocytes. Genomic DNA was extracted from uncultured amniocytes obtained from 23 patients. TaqMan polymerase chain reaction (PCR) primers were designed to amplify the potassium voltage gated channel gene on chromosome 21q22.12 and the ribosomal phosphoprotein gene on 18q21.1. Quantitative real-time PCR was performed for these two gene fragments and the differences of the threshold cycle (Ct) of the two genes (Ct 18-Ct 21) were calculated for each sample. RESULTS: G-banding revealed that 19 patients had a normal karyotype and four had trisomy 21. FISH resulted in one case of a false positive. The Delta Ct values (Ct 18-Ct 21) of trisomy 21 patients were significantly higher than the values of individuals with normal karyotypes (P < 0.001) and there was no overlapping. CONCLUSIONS: Fetal trisomy 21 is rapidly detectable by gene dosage analysis from amniocytes using quantitative real-time PCR.     

Prenatal diagnosis of mosaic trisomy 2 associated with abnormal maternal serum screening,oligohydramnios, intrauterine growth restriction,ventricular septal defect,preaxial polydactyly,and facial dysmorphism

ObjectiveTo present prenatal diagnosis of mosaic trisomy 2.Materials and MethodsA 29-year-old woman underwent amniocentesis at 17 weeks of gestation because of abnormal maternal serum screening, and the cytogenetic result was 47,XY,+2[8]/46,XY[22]. She underwent repeated amniocentesis at 19 weeks of gestation. Interphase fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH), and quantitative fluorescent polymerase chain reaction (QF-PCR) were performed on uncultured amniocytes. Ultrasound at 22 weeks of gestation revealed severe oligohydramnios, intrauterine growth restriction, and ventricular septal defect. The pregnancy was terminated at 22 weeks of gestation. Cytogenetic analysis was performed on parental blood, cultured amniocytes, cord blood, skin, liver, lung, umbilical cord, amnion, and placenta. aCGH analysis was performed on cord blood, skin, and liver.ResultsIn the samples of uncultured amniocytes, interphase FISH detected 11.1% (13/117) mosaicism for trisomy 2, aCGH analysis showed the result of arr [hg19] 2p25.3q37.3 (0–242,936,883)×2.46, and QF-PCR excluded uniparental disomy 2. QF-PCR on placenta revealed trisomy 2 derived from maternal meiosis I non-disjunction. Cytogenetic analysis revealed the following results: cultured amniocytes: 46,XY[21 colonies]; cord blood: 46,XY[40 cells]; skin: 46,XY[40 cells]; lung: 46,XY[40 cells]; liver: 47,XY,+2[4 cells]/46,XY[36 cells]; umbilical cord: 47,XY,+2[4 cells]/46,XY[36 cells]; amniotic membrane: 47,XY,+2[20 cells]/46,XY[20 cells]; and placenta: 47,XY,+2[40 cells]. The fetus postnatally manifested facial dysmorphism and preaxial polydactyly of the hand.ConclusionInterphase FISH and aCGH analyses on uncultured amniocytes are useful for rapid confirmation of low-level mosaic trisomy 2 at amniocentesis.     

Prenatal diagnosis of low-level mosaicism for a small supernumerary marker chromosome derived from chromosome 9q (9q13-q21.33) in a pregnancy with a favorable outcome,and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes

ObjectiveWe present prenatal diagnosis of low-level mosaicism for a small supernumerary marker chromosome (sSMC) derived from chromosome 9q (9q13-q21.33) in a pregnancy with a favorable outcome, and cytogenetic discrepancy between cultured amniocytes and uncultured amniocytes.Case reportA 36-year-old, primigravid woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Cytogenetic analysis on cultured amniocytes revealed a karyotype of 46,XY in 20/20 colonies. Simultaneous array comparative genomic hybridization (aCGH) on the DNA extracted from uncultured amniocytes revealed 30% mosaicism for a de novo 20.3-Mb gene dosage increase at 9q13-q21.33. Repeat amniocentesis and cordocentesis were performed at 21 weeks of gestation. Cytogenetic analysis on cord blood revealed a karyotype of 47,XY,+mar [3]/46,XY [37]. aCGH analysis of cord blood revealed 7.5% mosaicism for a 17.15-Mb gene dosage increase at 9q21.11-q21.33. aCGH analysis of uncultured amniocytes revealed 11.7% mosaicism for a 17.15-Mb gene dosage increase at 9q21.11-q21.33. Polymorphic DNA marker analysis excluded uniparental disomy 9. The parental karyotypes were normal. The pregnancy was carried to 37 weeks of gestation, and a 2955-g phenotypically normal male baby was delivered. At birth, the cord blood had a karyotype of 47,XY,+mar [3]/46,XY [37], the placenta had a karyotype of 47,XY,+mar [10]/46,XY [30], and the umbilical cord had a karyotype of 47,XY,+mar [14]/46,XY [36]. aCGH analysis on the DNA extracted from cord blood at birth revealed no genomic imbalance. Interphase fluorescence in situ hybridization analysis on buccal mucosal cells at age two months detected 3.8% (4/106 cells) mosaicism for the sSMC, compared with 2% (2/100 cells) in the normal control. The neonate had normal physical development at age two months.ConclusionCytogenetic discrepancy between cultured amniocytes and uncultured amniocytes may exist in the pregnancy with fetal mosaic sSMC. Low-level mosaicism for an sSMC derived from chromosome 9q13-q21.33 at prenatal diagnosis can be associated with a favorable outcome in the fetus.     

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。     

Mosaic trisomy 12 at amniocentesis: Prenatal diagnosis and molecular genetic analysis

ObjectiveThis study is aimed at prenatal diagnosis of mosaic trisomy 12 and reviewing the literature.Materials and MethodsA 34-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age. Cytogenetic analysis of cultured amniocytes revealed a karyotype of 47,XX,+12[9]/46,XX[14]. She was referred to the hospital for genetic counseling. Repeated amniocentesis was performed at 22 weeks of gestation. Array comparative genomic hybridization (aCGH), interphase fluorescence in situ hybridization (FISH) and quantitative fluorescent polymerase chain reaction (QF-PCR) were applied on uncultured amniocytes, and conventional cytogenetic analysis was applied on cultured amniocytes.ResultsThe aCGH analysis on uncultured amniocytes revealed a small genomic gain in chromosome 12. Interphase FISH analysis on uncultured amniocytes using a 12q11-q12-specific probe of RP11-496H24 (green spectrum) showed three green signals in 17.8% (8/45 cells) of uncultured amniocytes. QF-PCR analysis on uncultured amniocytes using chromosome 12-specific microsatellite markers excluded uniparental disomy 12. Cytogenetic analysis of cultured amniocytes revealed a karyotype of 47,XX,+12[5]/46,XX[25]. The parents decided to continue the pregnancy. A healthy 3270 g female baby was delivered at 39 weeks of gestation, with no phenotypic abnormalities. Cytogenetic analysis of the cord blood revealed a karyotype of 46,XX in 40/40 cultured lymphocytes. The neonate was normal in growth and psychomotor development at 6 months of age. Interphase FISH analysis on uncultured urinary cells revealed 5% (1/20 cells) mosaicism for trisomy 12.ConclusionPrenatal diagnosis of mosaic trisomy 12 at amniocentesis should alert a clinically significant aneuploidy. Interphase FISH and aCGH on uncultured amniocytes are useful for rapid confirmation of low-level trisomy 12 mosaicism at repeated amniocentesis.     

Prenatal diagnosis of mosaic trisomy 18 and maternal uniparental disomy 18 by amniocentesis in a pregnancy associated with cytogenetic discrepancy in various tissues and a favorable fetal outcome

ObjectiveWe present prenatal diagnosis of mosaic trisomy 18 and maternal uniparental disomy (UPD) 18 in a pregnancy with a favorable fetal outcome.Case reportA 34-year-old woman underwent amniocentesis at 17 weeks of gestation because of advanced maternal age, and the result was 47,XY,+18 [4]/46,XY [25] in cultured amniocytes. Simultaneous array comparative genomic hybridization (aCGH) on uncultured amniocytes revealed 65% mosaicism for trisomy 18. Prenatal ultrasound was normal. She consulted our hospital and underwent repeat amniocentesis at 22 weeks of gestation, and the result revealed a karyotype of 47,XY,+18 [9]/46,XY [12] in cultured amniocytes. Simultaneous aCGH on uncultured amniocytes revealed arr 18p11.32q23 × 2.4 (log₂ ratio = 0.3) consistent with 40% mosaicism for trisomy 18. Parental karyotypes were normal. Quantitative fluorescent polymerase chain reaction (QF-PCR) analysis on the DNA extracted from parental bloods and uncultured amniocytes confirmed maternal uniparental heterodisomy of chromosome 18. At 26 weeks of gestation, she underwent the third amniocentesis which revealed a karyotype of 47,XY,+18 [7]/46,XY [19] in cultured amniocytes. Simultaneous aCGH on uncultured amniocytes revealed arr 18p11.32q23 × 2.4 (log₂ ratio = 0.27) consistent with 40% mosaicism for trisomy 18. Interphase fluorescence in situ hybridization (FISH) on uncultured amniocytes revealed 38% (38/100 cells) mosaicism for trisomy 18. The woman was advised to continue the pregnancy, and a 2620-g phenotypically normal male baby was delivered at 40 weeks of gestation. At birth, the karyotypes of cord blood, umbilical cord and placenta were 47,XY,+18 [14]/46,XY [26], 47,XY,+18 [9]/46,XY [31] and 47,XY,+18 (40/40 cells), respectively. When follow-up at age 2½ months, the neonate was phenotypically normal. The peripheral blood had a karyotype of 47,XY,+18 [28]/46,XY [12], and interphase FISH analysis on buccal mucosal cells detected 6.4% (7/93 cells) mosaicism for trisomy 18, compared with 0% (0/100 cells) in the normal control. When follow-up at age seven months, the neonate was normal in development, and the peripheral blood had a karyotype of 47,XY,+18 [18]/46,XY [22].ConclusionsMosaic trisomy 18 at amniocentesis can be associated with cytogenetic discrepancy in various tissues, UPD 18 and a favorable fetal outcome. Prenatal diagnosis of mosaic trisomy 18 should alert the possibility of UPD 18 and include UPD testing.