46,XX男性和46，XX／45，X病例分析

目的 探讨性别决定区基因(SRY)在性分化和发育中的作用。方法 细胞遗传学核型分析以及PCR技术检测外周血SRY基因。结果 病例1的核型为46，XX，SRY( )。诊断为46，XX男性性反转综合征。病例2的核型为46，XX／45，X，SRY(-)。诊断为Turner嵌合型。结论 SRY基因检测比Y染色体更能预示睾丸组织的存在，是诊断性别发育异常患者的重要手段。性腺的病理取决于性腺组织的染色体核型和SRY基因。除SRY基因外，还存在多个参与性别决定和分化的基因，性分化异常表现高度遗传异常性。     

应用荧光原位杂交技术检测卵巢早衰患者X染色体嵌合型

目的　探讨卵巢早衰与低百分率 45 ,X/ 46,XX嵌合核型的关系 ,了解荧光原位杂交(FISH)技术检测染色体嵌合核型的敏感性和特异性。方法　取 18例卵巢早衰患者和 9例正常妇女(对照 )的外周血进行培养 ,行常规G显带和用X染色体记数探针行FISH ,对每例计数 60 0～ 70 0个细胞的荧光信号。结果　 18例卵巢早衰患者的常规染色体分析核型为 46,XX。卵巢早衰患者的 45 ,X/46,XX染色体嵌合型比率为 7.6% ,显著高于对照者的 2 .2 % ,两者比较 ,差异有极显著性 (P <0 .0 1)。结论　某些卵巢早衰患者的致病机理可能与 45 ,X/ 46,XX嵌合核型比例增高 ,X染色体数量不足有关。对此类低百分率染色体嵌合核型 ,FISH技术在敏感性和特异性上优于常规核型检查     

121例遗传咨询门诊病例的细胞遗传学分析

就1982年121例遗传咨询门诊所查7例染色体异常进行报道与分析。常规进行淋巴细胞培养G显带,部分病例选加C带。7例的异常核型是:46,XX,-21,t(21q21q);46,X,i(Xq);45,X/46,XX;45,X/46,XY;45,XX,t(13q14q)mat;45,XX,t(13q14q);46,XY,nv(q)。     

Turner综合征患者标记染色体的鉴定与分析

目的 分析11例携带标记染色体的Turner综合征患者的核型,研究这类染色体的表型效应。方法 选择11例具Turner综合征表型的患者,常规核型分析均显示为携带标记染色体的嵌合体,其中6例标记染色体呈环状。患者G带核型表示为mos．45,X／46,X,＋mar或者mos．45,X／46,X,＋r．以X／Y着丝粒探针,应用荧光原位杂交（FISH）技术分析这些标记染色体起源,对其中2例较大的环状染色体,结合反向染色体涂染确定断裂位点,比较不同断裂位点的标记染色体的遗传学效应。结果11例患者所携带的标记染色体均为环状染色体,r（X）的断裂位点分别位于Xp22、Xq22、Xq24、Xq26等。结论 Turner综合征患者的标记染色体主要来源于X染色体,且表现为r（X）形式。r（X）均以嵌合型的形式存在。     

细菌人工染色体标记-微球鉴别/分离法对1973份羊水的快速产前诊断

目的探讨细菌人工染色体标记-微球鉴别/分离法(bacterial artificial chromosomes-on-beads,BoBs)在产前诊断中的应用价值。方法对2015年1月至2016年6月西京医院产前诊断中心1973例有产前诊断指征的孕妇羊水细胞进行BoBs检测和染色体核型分析。结果 1973例羊水中,共发现异常核型150例,其中染色体核型分析检出145例,BoBs检出133例。不同产前诊断指征下,无创DNA产前检测(NIPT)高风险组的染色体异常检出率最高,占该指征的81.82%。150例异常核型中,BoBs和核型分析均检出染色体非整倍体124例,占异常核型的82.67%;BoBs检出染色体微缺失/微重复综合征5例,核型分析结果均未见异常;染色体核型分析检出性染色体嵌合7例,BoBs检出4例;染色体核型分析检出结构异常14例,BoBs结果未见异常。结论 BoBs技术可以快速检测染色体非整倍体和基因微缺失/微重复,联合染色体核型、基因芯片(chromosomal microarray analysis,CMA)及荧光原位杂交技术(fluorescence in situ hybridization,FISH)可对染色体结构异常和低嵌合正确检出,大大提高了产前诊断的效率与准确性。     

羊水细胞染色体核型分析和微列阵比较基因组杂交技术验证无创产前检测的临床意义

目的:探讨羊水细胞染色体核型分析技术和微列阵比较基因组杂交技术(array-CGH)验证无创产前检测(NIPT)的临床意义。方法:对NIPT提示信号异常的95例孕妇行羊膜腔穿刺术,抽取羊水进行培养后行染色体核型分析验证其符合率;同时对提示除外21-三体、18-三体、13-三体的常染色体异常(即其他常染色体异常)的患者行array-CGH分析,验证其符合率。结果:NIPT提示21-三体高风险的染色体核型分析符合率86.96%(40/46);18-三体的染色体核型分析符合率76.92%(10/13);13-三体染色体核型分析符合率0(0/2)。性染色体核型分析的符合率50.00%(9/18),其中1例性染色体异常的染色体核型分析为46,XX,del(Xq23-25),行array-CGH验证,提示为X染色体该区带11.9 M的片段缺失。其他常染色体异常的染色体核型分析符合率12.50%(2/16),其array-CGH验证的符合率25.00(4/16)。结论:NIPT的结果需要验证,经典的羊水细胞染色体核型分析技术可以验证胎儿染色体数目和结构异常,array-CGH可以验证微缺失或者微重复,分辨率更高。     

不同染色体核型Turner综合征的产前诊断指征和妊娠结局：205例分析

目的探讨不同染色体核型的Turner综合征(Turner syndrome, TS)的产前诊断指征和妊娠结局。方法回顾性分析广州市妇女儿童医疗中心产前诊断中心2010年1月1日至2021年6月30日产前诊断胎儿核型为TS者的临床信息。依据核型结果, 将这些病例分为X单体(核型为45,X)和非X单体类(核型包括X数目异常、等臂X、X缺失、X重排、假双着丝粒X和含Y数目异常嵌合体, 以及Y缺失)2类。采用χ2检验对TS的检出率、产前诊断指征和妊娠结局进行比较, 采用Bonferroni法进行亚组间两两比较, 采用χ2检验(或Fisher精确概率法)对超声异常征象进行比较, 采用Mann-WhitneyU检验对2组颈项透明层(nuchal translucency, NT)厚度进行比较。结果 (1)研究期间共27 981例行介入性产前诊断, 检出TS共205例(0.73%), 包括X单体(135例)和非X单体类(70例, 其中性染色体数目异常44例, 性染色体结构异常26例)。(2)205例中, 164例(80.0%)有1项产前诊断指征, 41例(20.0%)有多项产前诊断指征。X单体中, ...     

原发闭经表型的细胞遗传学病因研究

目的:探讨原发闭经表型的细胞遗传学病因。方法:运用常规的染色体核型分析技术及FISH、C-带和Q-带技术,分析25例原发闭经表型患者的染色体核型。结果:25例原发闭经表型病例中,18例核型异常,占72.0%。异常核型病例分别为:45,X 8例、46,XY 2例,等臂X 1例、嵌合核型4例(分别为45,X细胞系与不同的结构异常性染色体细胞系的嵌合体)、X长臂末端缺失1例、X-常染色体平衡易位2例。除这18例异常核型患者外,尚有7例为先天性无子宫、无阴道的原发闭经患者未检出核型异常。结论:X染色体数目单体、X结构异常、X染色体数目单体细胞系与结构异常性染色体细胞系的嵌合体核型、XY性发育异常(DSD)、X-常染色体平衡易位都可导致原发闭经表型。常规G-显带技术与C-带、Q-带技术及FISH技术相互结合,有助于进一步准确诊断核型。     

染色体与妇科医师

1959年以来细胞遗传学成为临床医学的一个重要诊断分支。同年报道了一些临床综合征染色体异常的重要发现:Lejeune等发现唐氏综合征中有一个多余的小近端着丝点染色体,Ford等报道Turner氏征患者只45个染色体及单个X染色体,Klinefelter综合征有一多余X染色体,睾丸女性化综合征有46,XY染色体组型,并描述了47,XXX综合征,报告了第1例嵌合现象-47,XXY/46,XXKlinefelter综合征。此后10年中又发现了100多种染色体异常,所用的技术以今日标准衡量似较为原始。 1970年Casperson等用芥子奎吖因(qainacrine mustard)染人体分裂中期染色体,在荧光的激发下,染色体全长呈现出特异的带,此发现在细胞遗传学上为一重要里程牌。1971年在为细胞遗     

单绒毛膜双羊膜囊双胎的染色体核型及表型不一致1例

单绒毛膜双胎通常被认为是同卵双胎, 理论上两个胎儿的基因100%相同。在单绒毛膜双胎中发生染色体核型不一致的情况非常少见。本文报道1例21三体不一致的同卵单绒毛膜双羊膜囊双胎。孕妇因早产临产于妊娠36周行剖宫产术分娩两女婴。产后发现新生儿1存在典型的21三体表型, 新生儿2表型未见明显异常。G显带染色体核型分析结果显示, 两新生儿核型均呈嵌合型, 分别为47, XX, +21[6]/46, XX[54]和47, XX, +21[7]/46, XX[53]。数字PCR技术结果显示, 两新生儿的嵌合现象均存在于外周血中。短串联重复序列分析结果显示, 此双胎为同卵双胎。单核苷酸多态性微阵列技术检测结果提示, 此双胎为同源嵌合体。本例提示, 单绒毛膜双羊膜囊双胎出现表型不一致时应警惕可能存在染色体核型不一致的现象, 外周血染色体核型分析不能完全诊断双胎的核型。     

Healthcare for adolescents with Turner syndrome

This review paper highlights important healthcare issues for adolescents with Turner Syndrome. Turner Syndrome potentially affects multiple organ systems including: cardiovascular, renal, endocrine, neurologic, gastrointestinal, skin, skeletal, auditory, and reproductive systems. Congenital and acquired cardiac defects remain the most significant health problem faced by women with Turner Syndrome.     

Anomalies de structure du chromosome Y et syndrome de Turner

Although specifically male, the human Y chromosome may be observed in female karyotypes, mostly in women with Turner syndrome stigmata. In women with isolated gonadal dysgenesis but otherwise normal stature, the testis determining factor or SRY gene may have been removed from the Y chromosome or may be mutated. In other women with Turner syndrome, the karyotype is usually abnormal and shows a frequent 45,X/46,XY mosaicism. In these cases, the phenotype depends on the ratio between Y positive and 45,X cell lines in the body. When in mosaicism, Y chromosomes are likely to carry structural abnormalities which explain mitotic instability, such as the existence of two centromeres. Dicentric Y isochromosomes for the short arm (idic[Yp]) or ring Y chromosomes (r[Y]) are the most frequent abnormal Y chromosomes found in infertile patients and in Turner syndrome in mosaic with 45,X cells. Although monocentric, deleted Y chromosomes for the long arm and those carrying microdeletions in the AZF region are also instable and are frequently associated with a 45,X cell line. Management of infertile patients carrying such abnormal Y chromosomes must take into account the risk and the consequences of a mosaicism in the offspring.     

Application of QF-PCR for the prenatal assessment of discordant monozygotic twins for fetal sex

OBJECTIVE: To establish the utility of quantitative fluorescent polymerase chain reaction (QF-PCR) in order to determine the zygosity of multiple pregnancies, as well as to define the origin of the most frequent aneuploidies in amniotic fluid samples. METHODS: We describe the case of a monochorionic (MC) diamniotic (DA) pregnancy with phenotypically discordant twins (nuchal cystic hygroma and non-immune hydrops in twin A and no anomalies in twin B). QF-PCR was performed for rapid prenatal diagnosis in uncultured amniocytes and subsequently in cultured cells. Polymorphic markers for chromosomes X, Y, 13, 18 and 21 were used for determination of zygosity as well as sex chromosome aneuploidy. RESULTS: Twin A showed a Turner Syndrome (TS) mosaicism pattern by QF-PCR in uncultured amniocytes. The monozygotic origin of the pregnancy was determined. Interphase fluorescence in situ hybridization (I-FISH) in this sample showed a mosaicism X0/XY (83/17%). Cytogenetic analysis revealed a 45,X0 karyotype in twin A and a 46,XY karyotype in twin B. CONCLUSIONS: QF-PCR is a reliable tool for the determination of the zygosity independently of the chorionicity and the fetal sex in case of twin pregnancy. Testing both direct and cultured cells can provide useful results for genetic counselling in chromosomal mosaicisms.     

Hygroma colli cysticum: prenatal diagnosis and prognosis.

The objective of this study is to analyze the prenatal management and prognostic factors of hygroma colli cysticum by using cytogenetic tests and sonographic morphological features. All cases with hygroma colli cysticum diagnosed and managed at our Prenatal Diagnostics Unit between January 96 and September 2000 were analyzed. Sonographic morphological features were divided in two groups; nonseptated (n = 18) and septated (n = 12) hygroma colli cysticum lesions were compared with fetal karyotype results and pregnancy outcome data. Statistical analysis was performed by Chi-square test and statistical significance was defined as p <0.05. In 5 years, 30 cases with hygroma colli cysticum were identified. Cytogenetic results were obtained from 23 (76.7%) cases (four chorionic villus sampling and 19 amniocentesis). Chromosomal abnormalities were present in 13 cases (56.5%). The most common chromosomal abnormality was Turner Syndrome (four cases, 17.4%) and Trisomy 18 (four cases, 17.4%). Pregnancy outcome data were available for 29 patients. Those fetuses with septated hygroma colli cysticum tended to have a worse fetal outcome, without statistical significance (p >0.05), compared with the nonseptated hygroma colli cysticum cases (75 vs. 61.1%, respectively). Fetal hygroma colli cysticum, either septated or not, carries high risks of aneuploidies and adverse fetal outcome. Recommended management includes karyotyping and if parents decide to continue the pregnancy ultrasound scan at 20 to 22 weeks' gestation is necessary, for excluding associated anomalies. At birth, if the cystic hygroma persists, it should be noted that a respiratory difficulty can happen and a pediatrician should standby as a precaution.     

Y-specific sequences in Turner syndrome]

Turner Syndrome (TS) is the only one monosomy that occurrs+ in humans. The cytogenetics of TS is very well known from years. It has been estimated that almost 98-99% of TS foetuses end in abortion. It was suggested that the monosomy arises relatively late during embryonal development and survived TS individuals could be mosaics. It has been proved that mosaic karyotype mos 45,X/46X, + mar(Y) occurrs++ in 2% to 11% of TS patients. The patients having additional cell line containing der(Y) are at increased risk of gonadoblastoma development. In these cases gonadectomy should be considered. Therefore detection of mosaic and establishing the origin of marker chromosome (specially containing Y-specific sequences) is of special importance. The aim of present study was to detect the small mosaics, containing mar(Y) in TS patients, by using PCR and FISH techniques. Eight Y sequences for the PCR analyses as well as bicolor in situ hybridisation with painting probes for Y and X chromosomes have been applied. The positive amplification for Y-specific sequences has been detected in 7% of TS patients. Our results support the thesis that searching for the Y sequences should be introduced to routine genetic TS diagnosis.     

Antenatal detection of cystic hygroma

Ultrasonographic evaluation, as a routine component of prenatal care, has significantly contributed to in utero assessment of pregnancy status. The detection of fetal abnormalities by ultrasound, however, has raised clinical questions and created parental dilemmas concerning the outcomes of such pregnancies. A relatively frequent anomaly observed on routine ultrasonographic examination is the posterior nuchal cystic hygroma. We report the prenatal detection of 16 cases of cystic hygromata and an analysis of a survey of the world's literature including an additional 155 cases. The information available from these 171 cases allows a clearer picture of the prognosis for fetuses in whom posterior cystic hygroma is detected in utero. Regarding outcome, 73.2 per cent of cases were terminated at the parents' request; 37 cases (22.6 per cent) resulted in fetal death in utero prior to any intervention. Only 7 per cent of continuing pregnancies resulted in live-born infants. Of the 142 cases with available cytogenetic findings, 22 per cent had normal karyotypes; 58 per cent had a karyotype associated with Turner syndrome phenotype; while autosomal trisomies and various structural abnormalities made up the remaining 20 per cent. Even among those fetuses with normal chromosomes, various physical anomalies were detected. Fetal hydrops was present in 66 per cent of the 102 cases with pertinent information. For those fetuses demonstrating cystic hygroma and normal karyotypes, Mendelian syndromes must be considered in the differential diagnosis. Alpha-fetoprotein evaluation of both maternal serum and amniotic fluid was not helpful in determining prognosis of these fetuses. The ultrasonographic finding of a posterior nuchal cystic hygroma, with or without accompanying fetal hydrops, is a valid indicator for a poor outcome of such pregnancies.     

The importance of chorionic villus sampling after first trimester diagnosis of cystic hygroma

The prenatal diagnosis of The Turner Syndrome is described at a menstrual age of 12 weeks. Detection of cystic hygroma was followed by vaginal chorionic villous sampling (CVS) which revealed a 45,X karyotype. Early documentation of fetal karyotype in the presence of a cystic hygroma is essential for accurate diagnosis and genetic counselling.     

A Spontaneous Pregnancy in a Patient with Turner Syndrome with 45,X/47,XXX Mosaicism: A Case Report and Review of the Literature

Background

Turner syndrome is a chromosomal abnormality, due to a total or partial loss of 1 of the X chromosomes and is mostly characterized clinically by short stature and primary ovarian insufficiency. Spontaneous pregnancies are rare (5%) and of relatively high risk. This is 1 of few reported cases of spontaneous conception and favorable prognosis in a patient with Turner syndrome and a 45,X/47,XXX karyotype.

Frequency and Types of Chromosomal Abnormalities in Turkish Women with Amenorrhea

Study ObjectiveTo estimate the frequency and the type of chromosomal abnormalities (CA) in patients with primary (PA) and secondary amenorrhea (SA).DesignThis retrospective study was comprised of patients had been referred to our laboratory between 1990 to 2008 and designed as original article.SettingMedical Faculty of Cukurova University in Turkey.ParticipantsChromosomal analysis was carried out on 393 patients with PA and SA that were referred to Cytogenetic laboratory of Medical Biology and Genetic Department, Faculty of Medicine, Çukurova University.InterventionsLymphocyte culturing depended karyotyping.Main Outcome MeasuresStandard lymphocyte culturing procedure and karyotyping was performed to all samples.ResultsPA and SA were identified in 393 patients. The karyotype was normal in 337 cases (85.8%) and abnormal in 56 (14.2%) patients. CAs were found in 54 (13.7%) and 2 (0.5%) of women with PA and SA, respectively. Females carrying rearrangements between autosomal and sex chromosomes were detected in 2% (8/393). The numerical abnormalities of the X chromosome were detected in 39.3% (22/56) (monosomy and mosaic). Structural abnormalities of the X and the other chromosomes were detected in 25.5% (13 of 56). Structural mosaicism of X chromosome was found in 5.4% (3 of 56). Male karyotype (46, XY) was found in 33.9% (19/56). The most frequently detected abnormality were X chromosome monosomies or mosaics.ConclusionsOur study revealed that some causes of amenorrhea could be due to CAs. Therefore, cytogenetic study should be important test in the evaluation of patients with PA or SA. The most common abnormality seen is 45,X karyotype (monosomy X/Turner Syndrome) and its variants.