荧光原位杂交技术检测骨髓增生异常综合征染色体异常的临床意义

目的:探讨荧光原位杂交(FISH)技术检测骨髓增生异常综合征(MDS)染色体异常的敏感性,特异性及临床意义。方法:采用细胞遗传学分析(CCA)和组合探针CSF1R/D5S23,D5S721(5q33),EGR1/D5S23,D5S721(5q31),D7S486/CSP7(7q31),D7S522/CSP7(7q31),D20S108/CSP8(20q12/CSP8)检测45例MDS患者骨髓细胞的染色体异常,并比较检测结果。结果:两种方法共检出染色体异常26例(58%),染色体数目异常9例,占34.6%;染色体结构异常13例,占50%;复杂核型4例。CCA检出+8和20q-各3例,7q-2例;FISH检出7号染色体异常8例占17.8%(8/45),两组间比较差异有统计学意义(P=0.0441713)。FISH检出+8和20q-各5例,5q-异常4例。7号染色体异常和复杂核型组与核型正常组比较转白率高。结论:组合探针检出MDS中5q-,-7/7q-,+8,20q-核型异常高于CCA,CCA结合FISH技术能提高MDS染色体异常的检出率,对于疾病诊断,判断预后具有重要价值。     

993例先天性智力低下患儿的细胞遗传学研究

本文对993例先天性智力低下患儿外周血淋巴细胞进行了G显带染色体分析,检出异常核型234例,检出率23.56%．其中常染色体数目异常190例（19.13%),常染色体结构异常27例（2.72%);性染色体数目异常12例（1.2%),性染色休结构异常5,例（0.51%)．提示先天性智力低下与染色体异常密切相关．     

胎儿稽留流产与染色体异常的关系及其影响因素分析

目的：探讨B超联合FISH实验室诊断技术分析胎儿稽留流产与染色体非整倍体关系并对其他影响因素进行综合分析。方法：采用FISH技术对广西267例B超诊断为稽留流产孕妇的胎儿绒毛组织行13,16,18,21,22,X,Y染色体数目检测,荧光显微镜下观察结果;采用SPSS13．0对相关数据进行统计分析。结果：267例稽留流产胎儿绒毛组织中,染色体数目异常95例,异常率35．6％,数目异常以三体最常见,其次为四体,少见部分单体;异常病例样本中存在多种染色体混合嵌合体现象,如混合嵌合三体（2n＋1／2n）,混合嵌合四体（2n＋2／2n）,混合嵌合单倍体、三体、四体（2n-1／2n＋l／2n＋2／2n）等;稽留流产与患者年龄、流产史、孕周具有显著相关性。结论：染色体数目异常与染色体混合嵌合均是稽留流产的重要原因,同时稽留流产发生与患者高龄、多次流产史、早期妊娠密切关系。     

染色体多态性与临床效应及生殖关系的探究

为了探讨人类染色体结构多态性与生殖异常临床效应的关系,按常规技术方法制备外周血淋巴细胞染色体,经G、C显带,对1 414例遗传咨询者进行核型分析,检出异常核型273例。其中多态性变异180例,占65.93%,非多态性异常核型93例,占34.07％。多态性变异包括D、G组短臂增长10例,次缢痕增长(包括1、9和16号染色体)35例,大Y染色体和小Y染色体 99例,Y染色体臂间倒位6例,9号染色体臂间倒位30例。结果表明,人类染色体多态性与流产、不孕不育、死胎、生育畸形儿等有相关性。     

无精和严重少精症患者的遗传缺陷分析——-附2例世界首报染色体异常核型

对217例无精和严重少精症患者外周血淋巴细胞染色体核型进行分析,并采用聚合酶链反应对7例Y染色体结构异常患者的AZFc区进行检测。发现187例无精症患者中检出异常核型77例（41.18%）（其中46,XY,t(6;14)(p21;p13),46,XY,t(8;12)(p21;q24)为世界首报核型）,主要涉及染色体异常（数目异常和结构异常）;染色体异态（Y染色体异态和9号染色体臂间倒位）及46,XX性反转;30例严重少精症患者中检出异常核型4例（13.33%）（结构异常和46,XX性反转）。由此可见,性染色体数目和结构异常是精子发生障碍的主要原因,其次常染色体的某些断裂点也可能影响精子发生。AZFc区的缺失与否与精子发生也有直接关系。     

MLPA-微阵列技术在Y染色体异常检测中的初步应用

摘要: 为了探讨MLPA-微阵列技术用于检测性染色体异常的可行性和精确性, 针对Y染色体上的3个基因TSPY(p11.2)、PRY(q11)和RBMY(q11.2)设计MLPA探针, 应用MLPA-微阵列技术对15例已知染色体核型的样品进行检测, 将检测结果与各样品核型分析和PCR的检测结果进行对照和比较。结果表明, MLPA-微阵列技术对上述各基因位点的检测结果与样品染色体核型基本吻合, 特别是对二例核型分析没有获得染色体结构异常信息的样品, MLPA-微阵列技术检测出Y染色体微小的缺失或指示某些未知染色体片段的信息, 并与PCR检测结果完全相符。表明文章报道的MLPA-微阵列技术能够检测核型分析无法分辨的微小变化和异常, 显示MLPA-微阵列技术在染色体异常分析中具有很高的检测效率和准确性, 相对于染色体核型分析具有明显的优势, 在临床染色体病诊断中具有较大的应用前景。     

229例流产绒毛染色体核型分析及两种长期培养方法比较

目的:探讨早期自然流产绒毛染色体核型分析在自然流产病因检测中的应用价值,并比较两种长期培养方法的差别。方法:选择孕早期自然流产的孕妇229例,在无菌条件下,从宫腔内取出绒毛,同时或单独经胰酶消化法与切碎贴壁法进行细胞培养,传代之后常规进行G显带,在显微镜下做核型分析。结果:229例流产胎儿绒毛,培养成功206例,成功率为89.96%。异常核型105例,异常率为50.97%,数目异常者101例,占异常核型的96.19%,以16三体最为多见。胰酶消化法的培养成功率及收获时间都显著优于直接贴壁法,差异具有统计学意义(P0.05)。结论:自然流产绒毛染色体核型分析对流产查因具有实用价值。胰酶消化法较切碎贴壁法对流产绒毛长期培养及染色体核型分析更具实用性。     

光学基因组图谱在染色体结构异常检测中的应用

染色体结构异常（structural variations,SVs）是临床中的常见现象,主要包括染色体缺失、重复、倒位和易位等,因其会引起基因融合、断裂或拷贝数改变,常导致疾病的发生。目前临床上对于SVs的检测多采用染色体核型、芯片分析或高通量测序等细胞遗传学或常规分子遗传学技术。近年来,随着检测技术的不断发展,隐匿性染色体平衡易位和微小片段的异常在产前诊断、新生儿遗传病、血液病及肿瘤等研究领域逐渐被重视,而传统的遗传学检测方法存在较为明显的局限性。光学基因组图谱（optical genome mapping,OGM）是近年来基于全新原理开发的分子遗传学检测技术,与传统技术相比,其对常规和隐匿性SVs（平衡易位、微小片段等）都有较强的检出能力,在多领域有较高的应用价值。但是OGM也存在一定的局限性,如其因灵敏度较高而需要其他手段辅助排除假阳性结果,在近着丝粒等无标记区域无法进行检测等。本文针对传统细胞遗传学检测技术和OGM对SVs的检测能力,OGM的优势、缺陷及其在肿瘤、儿科等领域的应用进行综述。     

ART患者早期流产组织染色体异常及相关因素分析

目的:分析ART患者早期流产组织染色体异常及其相关影响因素。方法:回顾性分析2013-2017年ART患者行早期流产组织染色体检查的409例样本,分析胚胎染色体非整倍性发生及其与女方年龄、不孕年限、不孕因素、促排卵指标之间的关系。结果:ART流产患者中,流产组织染色体非整倍性发生率为57.46%,发生频次以16三体占比最高(23.95%),其次是22三体(13.45%)及Turner(9.24%)。流产组织染色体非整倍性患者平均年龄高于染色体整倍性患者(P0.001)。16三体组患者年龄低于22三体(P0.01)及Turner组(P0.05)。16三体组患者平均Gn使用量低于22三体组(P0.05)。16三体组患者移植15天血HCG值低于22三体(P0.05)及Turner组(P0.01)。结论:ART患者流产组织染色体非整倍性与女方年龄正相关,但16三体及Turner的发生与女方年龄相关性不大,且16三体更容易引发早期流产。     

用间期荧光原位杂交检测卵巢癌细胞中X染色体数目的异常

为了探讨用荧光原位杂交技术（fluorescence in situ hybridization, FISH）检测卵巢癌细胞中性染色体拷贝数目异常的实验方法及其应用价值,收集18例新鲜卵巢癌组织标本,以Biotin标记的X染色体α-卫星DNA（pBamX7）探针与经处理的标本进行卵巢癌细胞核的原位杂交,分别用Avidin-FITC和Anti-avidin进行信号的检测与放大,PI复染。于Olympus AX-70型荧光显微镜下,通过WIB滤光镜观察杂交信号及其细胞核背景,并统计卵巢癌细胞核中的杂交信号颗粒数量。在显微镜下可见以Biotin标记的pBamX7探针显示绿色杂交信号,细胞核背景经PI复染显示桔红色;发现11/18（61%）卵巢癌标本中X染色体拷贝数增加,其余7例（39%）无拷贝数增加。X染色体拷贝数目增多在卵巢癌中有一定比例的发生频率,其在促进卵巢癌发病及其发展过程中起到某种作用,其意义值得进一步研究。     

Chromosomal abnormalities in couples with repeated fetal loss: An Indian retrospective study

BACKGROUND:

Recurrent pregnancy loss is a common occurrence and a matter of concern for couples planning the pregnancy. Chromosomal abnormalities, mainly balanced rearrangements, are common in couples with repeated miscarriages.

PURPOSE:

The purpose of this study is to evaluate the contribution of chromosomal anomalies causing repeated spontaneous miscarriages and provide detailed characterization of a few structurally altered chromosomes.

MATERIALS AND METHODS:

A retrospective cytogenetic study was carried out on 4859 individuals having a history of recurrent miscarriages. The cases were analyzed using G-banding and fluorescence in situ hybridization wherever necessary.

RESULTS:

Chromosomal rearrangements were found in 170 individuals (3.5%). Translocations were seen in 72 (42.35%) cases. Of these, reciprocal translocations constituted 42 (24.70%) cases while Robertsonian translocations were detected in 30 (17.64%) cases. 7 (4.11%) cases were mosaic, 8 (4.70%) had small supernumerary marker chromosomes and 1 (0.6%) had an interstitial microdeletion. Nearly, 78 (1.61%) cases with heteromorphic variants were seen of which inversion of Y chromosome (57.70%) and chromosome 9 pericentromeric variants (32.05%) were predominantly involved.

CONCLUSIONS:

Chromosomal analysis is an important etiological investigation in couples with repeated miscarriages. Characterization of variants/marker chromosome enable calculation of a more precise recurrent risk in a subsequent pregnancy thereby facilitating genetic counseling and deciding further reproductive options.     

Cytogenetic study of recurrent miscarriages and their parents

There is substantial evidence that genetic alterations are contributing factors to the risk for recurrent miscarriages. This study was conducted to determine the frequency and contribution of chromosomal abnormalities in miscarriages and in couples with recurrent miscarriages. We studied a total of 41 miscarriages and their parents with a history of 2–11 recurrent miscarriages. Chromosomal analysis from chorionic villus sampling (CVS) and fetal tissues were performed according to standard cytogenetic methods using G-banding technique. Major chromosomal aberrations and polymorphic variants were found in 51 and 4.8%, respectively. The chromosomal abnormalities were structural (34.4%) and numerical (65.1%) of which 26.1, 21.7, 8.7 and 8.7% were fetal sex aneuploid, triploid, mosaics and trisomic, respectively. Unbalanced and balanced rearrangements were found in 17.2 and 8.6% of all abnormalities, respectively. Major chromosomal abnormalities in couples were seen in 4.9%. The chromosomal abnormalities associated with pregnancy losses and recurrent miscarriages are mostly numerical ones. The incidence of balanced translocations found here is 4.9% which is near to the mode (about 3–6%) observed in the previous studies. Those frequencies are greater than in the general population (0.3%). This indicates that balanced translocations, seen in parents, have some importance in causing miscarriage. The major parental chromosomal aberrations are significantly associated with fetal wastage. Mosaicism should be taken into account for cytogenetic analyses of pregnancy losses. Thus, cytogenetic analyses should be recommended in couples with recurrent miscarriages, when clinical data fail to clarify the cause. The text was submitted by the authors in English.     

Cytogenetic study of recurrent miscarriages and their parents

There are substantial evidences that genetic alterations are contributing factors to the risk for recurrent miscarriages. This study was conducted to determine the frequency and contribution of chromosomal abnormalities in miscarriages and in couples with recurrent miscarriages. We studied a total of 41 miscarriages and their parents with a history of 2-11 recurrent miscarriages. Chromosomal analysis from chorionic villus sampling (CVS) and fetal tissues were performed according to standard cytogenetic methods using G-banding technique. Major chromosomal aberrations and polymorphic variants were found in 51 and 4.8%, respectively. The chromosomal abnormalities were structural (34.4%) and numerical (65.1%) of which 26.1, 21.7, 8.7 and 8.7% were fetal sex aneuploid, triploid, mosaics and trisomic, respectively. Unbalanced and balanced rearrangements were found in 17.2% and 8.6% of all abnormalities, respectively. Major chromosomal abnormalities in couples were seen in 4.9%. The chromosomal abnormalities associated with pregnancy losses and recurrent miscarriages are mostly numerical ones. The incidence of balanced translocations found here is 4.9% which is near to the mode (about 3-6%) observed in the previous studies. Those frequencies are greater than in the general population (0.3%). This indicates that balanced translocations, seen in parents, have some importance in causing miscarriage. The major parental chromosomal aberrations are significantly associated with fetal wastage. Mosaicism should be taken into account for cytogenetic analyses of pregnancy losses. Thus, cytogenetic analyses should be recommended in couples with recurrent miscarriages, when clinical data fail to clarify the cause.     

Chromosomal abnormalities as a cause of recurrent abortions in Egypt

BACKGROUND:

In 4%-8% of couples with recurrent abortion, at least one of the partners has chromosomal abnormality. Most spontaneous miscarriages which happen in the first and second trimesters are caused by chromosomal abnormalities. These chromosomal abnormalities may be either numerical or structural.

MATERIAL AND METHODS:

Cytogenetic study was done for 73 Egyptian couples who presented with recurrent abortion at Genetic Unit of Children Hospital, Mansoura University.

RESULTS:

We found that the frequency of chromosomal abnormalities was not significantly different from that reported worldwide. Chromosomal abnormalities were detected in 9 (6.1%) of 73 couples. Seven of chromosomal abnormalities were structural and two of them were numerical.

CONCLUSION:

Our results showed that 6.1% of the couples with recurrent abortion had chromosomal abnormalities, with no other abnormalities. We suggest that it is necessary to perform cytogenetic in vestigation for couples who have recurrent abortion.     

Comparative clinical genetic testing in spontaneous miscarriage: Insights from a study in Southern Chinese women

Single nucleotide polymorphism (SNP) array and karyotype analyses were conducted on 441 spontaneous miscarriage placental villous tissues collected from women from southern China. Subsequently, the results from these two analyses were compared to evaluate the best diagnostic strategy for subsequent pre-pregnancy planning. Here, the success rate of genetic testing using karyotyping and SNP array analysis was 78.46% (346/441) and 100.0% (441/441), respectively. The abnormality rate estimated by both methods was 54.9% (242/441). Three hundred and forty-six cases were successfully detected via both SNP array and karyotype analyses; the rate of consistent detection was 96.24% (333/346), whereas 13 cases were not consistent. There was no substantial positive correlation between age and genetic abnormalities such as Turner syndrome, structural variation or euploidy state in the different age groups studied. However, the aneuploidy rate was significantly different in each age group. Thus, although SNP array has higher success rate and resolution in genetic abnormality detection, supplementary karyotype analysis is needed for a more accurate revelation of the genetic aetiology of miscarriages. Therefore, this study indicates that simultaneous karyotype and SNP array analyses should be performed for spontaneous miscarriages. Furthermore, miscarriages irrespective of maternal age must be genetically analysed.     

Genetics of early miscarriage

A miscarriage is the most frequent complication of a pregnancy. Poor chromosome preparations, culture failure, or maternal cell contamination may hamper conventional karyotyping. Techniques such as chromosomal comparative genomic hybridization (chromosomal‐CGH), array-comparative genomic hybridization (array-CGH), fluorescence in situ hybridization (FISH), multiplex ligation-dependent probe amplification (MLPA) and quantitative fluorescent polymerase chain reaction (QF-PCR) enable us to trace submicroscopic abnormalities. We found the prevalence of chromosome abnormalities in women facing a single sporadic miscarriage to be 45% (95% CI: 38–52; 13 studies, 7012 samples). The prevalence of chromosome abnormalities in women experiencing a subsequent miscarriage after preceding recurrent miscarriage proved to be comparable: 39% (95% CI: 29–50; 6 studies 1359 samples). More chromosome abnormalities are detected by conventional karyotyping compared to FISH or MLPA only (chromosome region specific techniques), and the same amount of abnormalities compared to QF-PCR (chromosome region specific techniques) and chromosomal‐CGH and array-CGH (whole genome techniques) only. Molecular techniques could play a role as an additional technique when culture failure or maternal contamination occurs: recent studies show that by using array-CGH, an additional 5% of submicroscopic chromosome variants can be detected. Because of the small sample size as well as the unknown clinical relevance of these molecular aberrations, more and larger studies should be performed of submicroscopic chromosome abnormalities among sporadic miscarriage samples. For recurrent miscarriage samples molecular technique studies are relatively new. It has often been suggested that miscarriages are due to chromosomal abnormalities in more than 50%, but the present review has determined that chromosomal and submicroscopic genetic abnormalities on average are prevalent in maximally half of the miscarriage samples. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.     

Screening for Intellectual Disability Using High-Resolution CMA Technology in a Retrospective Cohort from Central Brazil

Intellectual disability is a complex, variable, and heterogeneous disorder, representing a disabling condition diagnosed worldwide, and the etiologies are multiple and highly heterogeneous. Microscopic chromosomal abnormalities and well-characterized genetic conditions are the most common causes of intellectual disability. Chromosomal Microarray Analysis analyses have made it possible to identify putatively pathogenic copy number variation that could explain the molecular etiology of intellectual disability. The aim of the current study was to identify possible submicroscopic genomic alterations using a high-density chromosomal microarray in a retrospective cohort of patients with otherwise undiagnosable intellectual disabilities referred by doctors from the public health system in Central Brazil. The CytoScan HD technology was used to detect changes in the genome copy number variation of patients who had intellectual disability and a normal karyotype. The analysis detected 18 CNVs in 60% of patients. Pathogenic CNVs represented about 22%, so it was possible to propose the etiology of intellectual disability for these patients. Likely pathogenic and unknown clinical significance CNVs represented 28% and 50%, respectively. Inherited and de novo CNVs were equally distributed. We report the nature of CNVs in patients from Central Brazil, representing a population not yet screened by microarray technologies.     

Chromosomal abnormalities associated with mental retardation in female subjects

Chromosomal abnormalities are thought to be the most common cause of mental retardation (MR). However, apart from a few selected types with typical aneuploidy, like Downs syndrome, Klinefelter syndrome, Turner syndrome, etc., the frequency of detectable chromosomal abnormalities in association with idiopathic MR is very low. In this study, we have investigated chromosomal abnormalities in female MR subjects (n = 150) by high-resolution GTG banding. Of them, 30 cases were diagnosed as Downs syndrome. Among the remaining (n = 120), chromosomal abnormalities/marked polymorphisms were detectable in only three MR cases (0.025).     

Evidence for high frequency of chromosomal mosaicism in spontaneous abortions revealed by interphase FISH analysis.

Numerical chromosomal imbalances are a common feature of spontaneous abortions. However, the incidence of mosaic forms of chromosomal abnormalities has not been evaluated. We have applied interphase multicolor fluorescence in situ hybridization using original DNA probes for chromosomes 1, 9, 13, 14, 15, 16, 18, 21, 22, X, and Y to study chromosomal abnormalities in 148 specimens of spontaneous abortions. We have detected chromosomal abnormalities in 89/148 (60.1%) of specimens. Among them, aneuploidy was detected in 74 samples (83.1%). In the remaining samples, polyploidy was detected. The mosaic forms of chromosome abnormality, including autosomal and sex chromosomal aneuploidies and polyploidy (31 and 12 cases, respectively), were observed in 43/89 (48.3%) of specimens. The most frequent mosaic form of aneuploidy was related to chromosome X (19 cases). The frequency of mosaic forms of chromosomal abnormalities in samples with male chromosomal complement was 50% (16/32 chromosomally abnormal), and in samples with female chromosomal complement, it was 47.4% (27/57 chromosomally abnormal). The present study demonstrates that the postzygotic or mitotic errors leading to chromosomal mosaicism in spontaneous abortions are more frequent than previously suspected. Chromosomal mosaicism may contribute significantly to both pregnancy complications and spontaneous fetal loss.     

超声心动图检查指标与胎儿染色体异常的相关性

摘要 目的：探究超声心动图检查指标与胎儿染色体异常之间的相关性。方法：选择2017年1月至2020年1月于我院接受产前超声心动图检查的980例高危产妇为研究对象,均对其开展超声心动图以及染色体核型检测,记录受检者染色体核型异常具体情况,筛选出染色体核型异常产妇（80例）作为研究组,设另900例染色体正常产妇为对照组,就两组产妇的超声心动图检查指标左心室Tei指数、右心室Tei指数以及颈项透明层厚度（NT）值差异进行比较,Spearman相关性分析探究上述超声心动图指标的相关性,最后绘制心动图指标对染色体异常的诊断ROC曲线图并计算AUC值。结果：（1）比较显示研究组胎儿的左心室Tei指数、右心室Tei指数和NT值均明显的高于对照组胎儿,组间差异具有统计学意义（P<0.05）;（2）相关性分析显示NT值同染色体异常胎儿的左心室Tei值、右心室Tei值均呈现明显的正相关联系（r=0.8927,r=0.9315,P<0.0001）;（3）ROC曲线绘制显示左心室Tei值、右心室Tei值和NT值对胎儿染色体异常的诊断AUC分别为0.9889、0.7574、0.7959（P<0.05）。结论：超声心动图检查指标同胎儿的染色体异常之间存在明显的关联性,可以考虑将超声心动图作为胎儿染色体异常的初筛手段,推广于临床应用。