微阵列比较基因组杂交技术对一例胎儿染色体复杂易位的产前诊断

目的对1例5条染色体发生复杂易位的胎儿作出产前诊断,评价微阵列比较基因组杂交（array—CGH）技术在产前诊断中的应用价值。方法应用G显带分析羊水细胞染色体及夫妇双方外周血染色体,应用array—CGH技术对羊水细胞进行全基因组高分辨扫描分析,了解是否有微小缺失和重复。结果羊水细胞染色体结果为46,XX,t（5;7;12）,t（14;21）,夫妻双方外周血染色体核型正常,羊水细胞array—CGH结果显示胎儿染色体未发生微缺失或微重复。结论array—CGH技术与传统细胞学技术相结合,大大提升产前诊断技术水平。     

联合运用多种技术鉴别四例胎儿新发标记染色体

目的探讨传统细胞遗传学技术联合SNP - array （ single nucleotide polymorphisms array, SNP - array）在识别胎儿微小额外标记染色体（ supernumerary marker chromosome, sSMC）致病性中的临床应用价值。方法通过常规G显带技术分析胎儿染色体核型,针对发现的sSMC,应用C显带技术分析ssMC,如果sSMC非异染色质,进一步进行SNP—array辨别其来源并分析相应的表型。结果通过对8575例产前诊断标本G显带核型分析发现4例新发标记染色体,其中C显带示2例为异染色质结构,2例为非异染色质结构。这2例非异染色质结构病例进一步行SNP—array检测,结果示一例未见致病性改变,另一例为4号染色体部分重复。结论SNP—array能够在基因组水平上识别胎儿sSMC的成分,结合传统的细胞遗传学技术应用于产前诊断中,为确定sSMC的致病性提供了可靠的产前诊断技术平台。     

应用微阵列比较基因组杂交技术对胎儿复杂染色体易位的产前诊断

目的对产前羊水细胞培养染色体核型分析,检测出染色体易位的胎儿应查父母双方染色体,并用基于芯片的微阵列比较基因组杂交(array comparative genomic hybridization,a CGH)技术检测,以明确其易位染色体的来源及胎儿染色体有无微重复或微缺失,探讨微阵列比较基因组杂交(a CGH)技术在检测胎儿染色体异常中的临床价值。方法通过胎儿羊水细胞培养,染色体G显带核型分析,诊断出胎儿染色体异常,核型为46,X,t(X;13;9)(q13;q14;p22),t(3;6)(p13;q23)。对此例标本进行a CGH分析,通过多位点高分辨率扫描确定胎儿染色体有无微重复或微缺失。结果a CGH扫描检测出胎儿染色体在Xq13.1-q13.2(71,699,190-71,820,393)区带存在121kb的缺失,在13q14.2-q21.1(48,706,590-57,520,639)区带存在8.8Mb的缺失。结论利用a CGH技术可以方便快速地鉴定和分析染色体的微重复或微缺失,结合传统的核型分析技术,可以为判断重复或缺失染色体片段的遗传学效应和产前诊断提供帮助。     

微阵列基因组杂交技术在22q11．21微缺失家系中的应用研究

目的了解反复孕育严重先天性心脏病儿、胎儿父亲患有原发性甲状旁腺功能低下家系的基因组拷贝数变化,确定其发病的遗传学原因。方法对常规染色体核型分析未见异常的法洛氏四联症胎儿及其整个家系中的7人采用微阵列基因组杂交（array—based comparative genomic hybridization,array—CGH）技术进行基因组拷贝数变化的检测分析（copy number variations,CNVs）。结果经过array—CGH分析,在胎儿及其父亲的22q11．21均发现存在2．52Mb的致病性缺失片段,位于18,919,942—21,440,514区段。家系中其他成员未发现同样的片段异常。结论22q11．21微缺失是导致其父亲患原发性甲状旁腺功能减退的遗传学原因,也是该家系多次孕育严重先天性心脏病患儿的原因,同时表明22q11．21微缺失表型多样,临床症状差异大。array—CGH是一种高通量、高分辨率及高准确性的遗传学分析技术,能够发现染色体片段上的亚微结构异常,是临床遗传学研究的重要工具。     

产前诊断胎儿7q11.23重复综合征一例

目的报告一例7q11.23重复综合征胎儿,探讨多种产前诊断技术的联合应用价值,为患者提供可靠的遗传咨询。方法采集1例孕中期胎儿的羊水行染色体核型分析,并提取羊水DNA,进行BoBs检测和单核苷酸多态性微阵列芯片(single nucleotide polymorphism array,SNP array)检测。结果胎儿羊水细胞染色体核型未见异常;BoBs检测结果提示胎儿7q11.23区域可见重复;SNP array检测结果显示胎儿7q11.23区段存在1.4Mb片段的重复,提示arr[hg19]7q11.23(72,701,098-74,162,823)×3。结论染色体核型分析联合BoBs检测,并用SNP array验证,明确诊断一例7q11.23重复综合征胎儿,在产前诊断中具有较好的应用价值。     

应用BACs-on-Beads等技术对一例Wolf-Hirschhorn综合征的产前诊断

目的应用BoBs(BACs-on-Beads)等多种技术对一例WHS(Wolf-Hirschhorn综合征)进行产前诊断,评价BACs-on-Beads技术在产前诊断中的应用价值和探讨Wolf-Hirschhorn综合征胎儿的遗传学特征。方法应用染色体G显带核型分析技术、BoBs技术和SNP array技术从多个水平对Wolf-Hirschhorn综合征胎儿断裂位点进行识别与定位。结果首先经由BoBs技术发现的这例Wolf-Hirschhorn综合征利用染色体G带核型分析和SNP array技术证实4号染色体4p16.3p15.31区段存在18.6Mb片段的缺失。结论 BACs-on-Beads技术应用于产前诊断有利于提升技术水平。     

5号和18号染色体变异致多发畸形的临床报道和遗传学分析

目的明确一例多发畸形患儿染色体拷贝数变异的性质,分析其染色体变异与表型的相关性。方法首先应用常规G显带分析该例患儿外周血染色体改变,然后应用比较基因组杂交芯片（array comparative genomic hybridization, array CGH ）对该例常规核型分析的结果进行精确定位。结果该患儿常规核型分析为46,XY,inv（9）（p12q13）,Yqh＋。arrayCGH结果为dup（5）（p14．1p15．33）区段（151,737—28,789,424）存在28．64Mb重复;del（18）（q22．1q23）区段（63,993,067—77,982,126）存在13．99Mb缺失。临床表现为面容特殊、眼裂小、牙齿反颌、隐形脊柱裂及脚趾畸形等。结论5号和18号染色体拷贝数变异可导致患儿出现多发畸形;与传统的细胞遗传学分析方法相比,arrayCGH在染色体异常分析中具有更高的分辨率和准确性。     

微阵列比较基因组杂交技术在染色体异常细胞遗传学分析中的应用

目的分析染色体G显带核型异常患者基因拷贝数变异(CNVs)情况,探讨微阵列比较基因组杂交(array CGH)技术在染色体异常细胞遗传学分析中的作用。方法收集受试者外周血标本,array CGH技术分析染色体易位、标记染色体以及性染色体异常患者CNVs情况及其临床意义。结果 array CGH分析发现染色体核型为45,XY,t(18;21)(18p11;21p11),15ps+的易位患者染色体18p11.3存在缺失,17q21.31存在扩增,18号染色体与21号染色体为非平衡易位,未检测到染色体15ps+相关CNVs;核型为47,XX,15ps-,+mar患者存在Y染色体相关CNVs,其标记染色体可能来源于Y染色体;核型为45,X/46,XY的性染色体异常患者染色体15q11.2存在缺失、15q13.3和22q11.23存在扩增,未检测到性染色体数目异常相关CNVs。结论 array CGH技术在临床细胞遗传学分析中具有重要的价值,该技术应用于CNVs分析有利于筛查病理性CNVs,明确染色体易位类型,辅助了解标记染色体的来源,但可能不适用于嵌合体以及染色体随体异常的检测。     

441例胎儿脐血染色体核型分析

目的通过对妊娠中晚期产前诊断指征,及对产前筛查高风险胎儿进行脐血染色体核型分析,探讨胎儿脐血染色体分析在产前诊断中的应用价值。方法对2010年1月—2012年12月于我院就诊的441例具有产前诊断指征的孕妇,在B超引导下行脐带穿刺术,取脐血细胞培养,染色体制备及胎儿染色体核型分析。结果在441例产前诊断孕妇中,共检出异常核型49例,包括染色体数目异常23例,结构异常26例,胎儿染色体异常率为11.11%。结论脐血细胞培养染色体核型分析,为胎儿染色体异常临床诊断提供了可靠依据,在产前诊断中具有重要的作用。     

单核苷酸多态性微阵列分析在产前基因诊断中的应用价值

目的评价单核苷酸多态性微阵列分析技术(single nucleotide polymorphism array,SNP array)在产前基因诊断中的临床应用价值。方法选择2016年1月至2017年2月在佛山市妇幼保健院产前诊断中心就诊的单胎孕妇进行遗传咨询,238例自愿进行产前诊断的孕妇抽取羊水或脐血进行常规G显带染色体核型分析,对其中染色体核型分析正常的143例病例进一步行SNP array,对SNP array确认拷贝数变异(copy number variant CNV)的病例,同时检测双亲样本,以明确变异的遗传性质及相关临床意义。结果染色体核型分析正常的143例病例行SNP array,检出7例致病性CNVS(4.9%),其中有1例单亲二倍体,2例临床意义不明确的CNVS(1.4%)。对这9例胎儿的双亲进行SNP array均未发现异常。结论 SNP array技术较传统的染色体核型分析方法能显著提高染色体拷贝数异常的检出率。SNP array技术是重要的产前基因诊断方法,可以尽可能的查找胎儿的遗传学病因,有利于产前临床咨询中正确评估胎儿的预后,为孕妇是否继续妊娠提供更客观的理论依据。     

Distribution of Epidermal Growth Factor Receptor Protein Correlates with Gain in Chromosome 7 Revealed by Comparative Genomic Hybridization after Microdissection in Glioblastoma Multiforme

In a recent study, 23 microdissected areas of 10 glioblastoma multiforme (GBM) were investigated for quantitative genomic aberrations using comparative genomic hybridization (CGH). To validate the chromosomal aberrations, as revealed by CGH after microdissection, parallel tissue sections were stained immunohistochemically with an antibody that detects both wild-type epidermal growth factor receptor (EGFR) and the deletion mutant form of the receptor (EGFRvIII). Immunostaining was correlated with CGH data of chromosome 7, because chromosome 7 is the most frequently aberrant chromosome in GBM (here four of 10 tumors), and this aberration often indicates an abnormality of EGFR. Nine of nine areas that showed gain in or amplification (2 areas) of chromosome 7 with CGH contained EGFR-immunoreactive cells. Only three of 14 areas without abnormality of chromosome 7 in CGH contained EGFR-immunoreactive cells; eleven of 14 areas were immunonegative. Our findings demonstrate a strong correlation between immunohistochemistry of EGFR and the copy numbers of chromosome 7, as revealed by CGH after microdissection in glioblastoma multiforme.     

2052例羊水细胞产前诊断的染色体结果分析

目的探讨孕中期羊膜腔穿刺产前诊断胎儿染色体异常的经验。方法收集、分析孕中期羊水培养核型分析结果资料。主要的产前诊断指征包括高龄、产前血清学筛查高风险、胎儿超声检查异常等。染色体异常包括常染色体非整倍体,性染色体非整倍体及染色体结构异常。结果成功培养羊水细胞2052例,其中指征为高龄孕妇的占16．0％．血清学筛查阳性占75．0％,胎儿超声检查异常占4．5％,其它原因占4．5％。检出率最高的指征为胎儿超声检查异常。共检出75例染色体异常胎儿,其中非整倍体为51例（68．0％）,染色体结构异常24例（32．0％）。结论本研究证明了羊水细胞用于诊断染色体异常胎儿的作用,其结果可用于临床遗传咨询。     

Placental mosaicism in the era of chromosomal microarrays

ObjectivePlacental mosaicism for a subset of a chromosome, a structural chromosomal aberration, is thought to be a very rare finding in chorionic villus samples. Here, we present clinical and laboratory data on five cases with such mosaicism for structural chromosomal aberrations.MethodsDuring a period of 6 months, chromosomal microarray was carried out on DNA extracted from 100 uncultured chorion villous samples from high-risk pregnancies.ResultsIn five of 100 consecutively collected samples (5/100), mosaicism for a structural chromosomal aberration was detected. The mosaic aberration was subsequently detected in fetal tissue in three of the five cases.ConclusionChromosomal microarray can detect placental mosaicism for structural chromosomal aberrations. This kind of mosaicism may be more frequent than previously anticipated, and the fetal involvement seems difficult to predict. These findings highlight the complexity of mosaicism for structural chromosomal aberrations in prenatal samples in the chromosomal microarray era.     

柳州地区6876例产前诊断羊水细胞染色体核型分析

目的分析妊娠中期进行产前诊断的高危孕妇羊水细胞染色体核型,了解此期异常核型出现的频率及类型。方法6887例具备产前诊断指征的妊娠妇女,在知情选择的情况下行羊膜腔穿刺术及染色体核型检测。结果6876例羊水细胞培养成功,成功率为99．84％（6876／6887）。在6876例羊水细胞培养成功的染色体核型中,检出异常核型107例,异常率为1．56％,常见核型为三体型,占异常核型47．66％。结论羊水细胞学检查作为一项产前诊断技术对于指导优生优育,降低缺陷儿的出生具有重要意义。     

分子细胞遗传学技术在确诊9p三体综合征中的应用

目的　用分子细胞遗传学技术鉴别常规细胞遗传学难以确定的染色体异常。方法　用染色体涂染、比较基因组杂交(com parative genom ic hybridization,CGH)和多色显带分析技术(colorbandingchrom osom e analysis,RxFISH),对一例G 显带提示为9 号染色体结构异常的病例进行研究。结果　患儿核型为46,XX,9p ,染色体涂染显示两条9 号染色体(包括短臂额外片段)被均匀涂染,CGH 和RxFISH证实为9 号短臂完全重复,核型准确描述为46,XX,dup 9p(p11→p24∷p24→qter)。结论　这些技术手段可以鉴别常规细胞遗传学难以进行诊断的、复杂的染色体结构异常,在基础及临床医学研究领域中,有着重要的应用前景     

Across array comparative genomic hybridization: a strategy to reduce reference channel hybridizations

Array comparative genomic hybridization (array CGH) is widely used for studying chromosomal copy number aberrations (CNAs) on a genome-wide and high-resolution scale in heritable disorders and cancers. The aim of this study was to test if the separate channels of dual channel arrays can be interchanged (across array) to either make array CGH more sensitive and cost effective and/or to generate profiles of CNAs and copy number variations (CNVs). Therefore the BT474 breast cancer cell line was compared with a mix of normal reference DNAs hybridized on different arrays and days and DNA copy number profiles were evaluated. Quality was assessed, using regular dual channel array CGH as a standard, using four quality measures, i.e., the median absolute deviation value of chromosome 2, the amplitude of the ERBB2 gene amplification, a deletion on chromosome 9, and the deflection on chromosome 8. The quality of the across array CGH profiles matched or even surpassed the quality of regular dual channel array CGH. In addition, this across array approach was tested for genomic DNA derived from formalin-fixed paraffin-embedded tumors tissue samples, resulting in high-quality copy number profiles, comparable to regular dual channel arrays. Finally, we demonstrated this approach to obtain both CNA and CNV profiles. In summary, across array CGH avoids redundant hybridizations of the same reference material in every experiment either allowing hybridization of two test samples on one array or producing both CNA and CNV profiles simultaneously.     

Fryns syndrome phenotype caused by chromosome microdeletions at 15q26.2 and 8p23.1

Background: Fryns syndrome (FS) is the commonest autosomal recessive syndrome in which congenital diaphragmatic hernia (CDH) is a cardinal feature. It has been estimated that 10% of patients with CDH have FS. The autosomal recessive inheritance in FS contrasts with the sporadic inheritance for the majority of patients with CDH and renders the correct diagnosis critical for accurate genetic counselling. The cause of FS is unknown. Methods: We have used array comparative genomic hybridisation (array CGH) to screen patients who have CDH and additional phenotypic anomalies consistent with FS for cryptic chromosome aberrations. Results: We present three probands who were previously diagnosed with FS who had submicroscopic chromosome deletions detected by array CGH after normal karyotyping with G-banded chromosome analysis. Two female infants were found to have microdeletions involving chromosome band 15q26.2 and one male had a deletion of chromosome band 8p23.1. Conclusions: We conclude that phenotypes similar to FS can be caused by submicroscopic chromosome deletions and that high resolution karyotyping, including array CGH if possible, should be performed prior to the diagnosis of FS to provide an accurate recurrence risk in patients with CDH and physical anomalies consistent with FS.     

Microarray comparative genomic hybridization (CGH)-based prenatal diagnosis for chromosome abnormalities using cell-free fetal DNA in amniotic fluid

Cell-free fetal DNA (cffDNA) in the supernatant of amniotic fluid, which is usually discarded, can be used as a sample for prenatal diagnosis. For rapid prenatal diagnosis of frequent chromosome abnormalities, for example trisomies 13, 18, and 21, and monosomy X, using cffDNA, we have developed a targeted microarray-based comparative genomic hybridization (CGH) panel on which BAC clones from chromosomes 13, 18, 21, X, and Y were spotted. Microarray-CGH analysis was performed for a total of 13 fetuses with congenital anomalies using cffDNA from their uncultured amniotic fluid. Microarray CGH with cffDNA led to successful molecular karyotyping for 12 of 13 fetuses within 5 days. Karyotypes of the 12 fetuses (one case of trisomy 13, two of trisomy 18, two of trisomy 21, one of monosomy X, and six of normal karyotype) were later confirmed by conventional chromosome analysis using cultured amniocytes. The one fetus whose molecular-karyotype was indicated as normal by microarray CGH actually had a balanced translocation, 45,XY,der(14;21)(q10;q10). The results indicated that microarray CGH with cffDNA is a useful rapid prenatal diagnostic method at late gestation for chromosome abnormalities with copy-number changes, especially when combined with conventional karyotyping of cultured amniocytes.