羊水衍生X染色体的细胞与分子遗传学分析

目的 对1例孕中期胎儿46,X,der(X)行细胞与分子遗传学研究,并探讨其临床效应.方法 采用羊水细胞培养和G、C显带技术制备染色体,应用X染色体计数探针、Y染色体计数探针、Tel Xp/Yp三色荧光原位杂交技术(fluorescence in situ hybridization,FISH)进一步分析确定其核型.结果 衍生染色体为罕见的X/Y染色体的易位,其核型为:46,X,der(X)t(X;Y)(p22.3;q11.2).ish der(X)t(X;Y)(p22.3;q11.2)(X/Ypter-,DXZ1+,DYZ1+)mat.结论 FISH结合细胞遗传学检测可以查明衍生染色体的来源和性质,从而为产前诊断提供更全面准确的遗传学依据,并能预测胎儿发生畸形的风险及准确地判断预后.     

羊水衍生X染色体的细胞与分子遗传学分析

目的 对1例孕中期胎儿46,X,der(X)行细胞与分子遗传学研究,并探讨其临床效应.方法 采用羊水细胞培养和G、C显带技术制备染色体,应用X染色体计数探针、Y染色体计数探针、Tel Xp/Yp三色荧光原位杂交技术(fluorescence in situ hybridization,FISH)进一步分析确定其核型.结果 衍生染色体为罕见的X/Y染色体的易位,其核型为:46,X,der(X)t(X;Y)(p22.3;q11.2).ish der(X)t(X;Y)(p22.3;q11.2)(X/Ypter-,DXZ1+,DYZ1+)mat.结论 FISH结合细胞遗传学检测可以查明衍生染色体的来源和性质,从而为产前诊断提供更全面准确的遗传学依据,并能预测胎儿发生畸形的风险及准确地判断预后.

Abstract：

Objective To analyze the aberrant der(X) chromosome using conventional and molecular cytogenetic approaches in a fetus of second trimester and to discuss its clinical effect. Methods Conventional cytogenetic procedures (GTG and CBG banding) were performed on cultured amniotic fluid cells. Threecolor fluorescence in situ hybridization (FISH) consisting of X chromosome enumeration probes(CEPX),CEPY and Tel Xp/Yp was further performed to study the aberrant der(X) chromosome. Results Der(X)was a rare X/Y translocation. The final karyotypes of the fetus was designated as: 46, X, der (X) t (X ; Y)(p22.3;q11. 2).ishder(X)t(X;Y)(p22.3;q11. 2)(X/Ypter-, DXZ1+, DYZ1+)mat. Conclusion The combination of FISH and conventional cytogenetic techniques is a powerful tool to determine derivative chromosome and to offer an accurate genetic counseling. Identification of Xp; Yq rearrangement can help estimate the risk of fetus abnormalities and give a more precise prognosis.     

一例母源性46,Y,der(X)t(X;Y)(p22;q11)染色体非平衡易位患儿的遗传学分析

目的对1例临床表征为身材矮小、鼻根部内陷、双侧隐睾、智力低下患儿进行遗传学分析,探讨该染色体结构异常与临床表征之间的关系。方法应用G显带染色体核型分析及染色体微阵列分析(chromosomal microarray analysis,CMA)技术对患儿进行遗传学检测,并对其父母进行外周血染色体核型分析。结果G显带分析结果显示患儿染色体核型为46,Y,der(X)t(X;Y)(p22;q11),mat。CMA检测结果提示患儿X染色体短臂Xp22.33p22.31存在约8.3 Mb片段缺失,Y染色体长臂Yq11.221qter存在约43.3 Mb片段重复。其父亲染色体核型正常,母亲染色体核型结果为46,X,der(X)t(X;Y)(p22;q11)。结论患儿携带母源性der(X)t(X;Y)(p22;q11)染色体非平衡易位,携带者的表型与其性别以及X染色体缺失片段的大小和位置密切相关。男性携带者智力障碍、生长发育落后等异常表型较女性更为严重。     

罕见Down-Turner双重综合征的遗传学研究

目的 对1例复杂染色体核型的Down-Turner双重综合征进行分子细胞遗传学分析,以指导临床遗传咨询和诊断.方法 在常规染色体核型分析的基础上,结合荧光原位杂交技术并进行家系遗传分析.结果 1例Down-Turner双重综合征患儿染色体核型确诊为46,X,+mar.ish i(14 0r 22)(p10)(D14Z1/D22Z1+)[32]/47,X,der(X)t(X;21)(p22.3;q11.2),+mar.ish der(X)(D21Z1+,Xpter-).ish i(14 0r 22)(p10)(D14Z1/D22Z1+)[28],其中标记染色体来源于其母亲.结论 Down-Turner双重综合征染色体核型复杂多样,有必要采用常规显带技术、荧光原位杂交技术和家族遗传分析等相结合的方法进行诊断,以便为临床遗传咨询和诊断提供精确的遗传学指导依据.     

21号环状染色体嵌合体胎儿2例的临床特征和遗传学分析

目的探讨2例21号环状染色体嵌合体胎儿的围产期临床表型和遗传学特征。方法选取2021年11月在厦门市妇幼保健院接受介入性产前诊断的2例胎儿为研究对象。收集2例胎儿的临床资料, 应用常规G显带核型分析和染色体微阵列分析(CMA)对2例胎儿及其父母进行遗传学检测。结果胎儿1超声提示胎儿鼻骨未显示、室间隔缺损、永存左上腔静脉、三尖瓣轻度返流, 染色体核型结果为46, X?, dic r(21;21)(p12q22;q22p12)[41]/45, X?, -21[9], CMA检测结果提示其染色体21q11.2q22.3区存在30.00 Mb片段的4拷贝, 21q22.3区存在3.00 Mb片段的缺失。胎儿2超声提示鼻骨呈点状回声, 核型为46, X?, r(21)(p12q22)[83]/45, X?, -21[14]/46, X?, dic r(21;21)(p12q22;q22p12)[3], CMA结果提示其染色体21q22.12q22.3区存在5.10 Mb片段的4拷贝, 21q22.3区存在2.30 Mb片段的缺失。结论 2例21号环状染色体嵌合体的围产期表型与靠近染色体缺失断裂位...     

一例罕见复杂染色体重排产前诊断

目的 探讨细胞遗传及荧光原位杂交（FISH）技术产前诊断一例罕见新发复杂染色体重排（CCR）的应用价值。方法 对1例产前胎儿复杂异常染色体重排应用细胞遗传及FISH技术初步确定其来源和结构。结果 经鉴定胎儿核型为46,XY,ins(2;3)(p13;p13p23),der(4)ins(4;9;2)(q25;q32q33;p13pter),der(9)ins(9;4)(q32;qterq25)dn。结论 FISH技术及分子细胞遗传学技术有助于对产前罕见复杂染色体重排染色体的准确识别及鉴定,并为进一步分子细胞检测如SNP、WES、WGS等指明方向。     

应用光谱染色体核型分析技术研究胰腺癌细胞系P2染色体核型

目的 探讨胰腺癌的细胞遗传学特征.方法 采用光谱核型分析技术对中国人胰腺癌细胞系P2的染色体核型进行分析,并选择EGFR/CEP 7双色荧光原位杂交(FISH)探针,对比分析10例胰腺癌和10例慢性胰腺炎石蜡标本的EGFR基因拷贝数,验证光谱核型分析结果.结果 P2细胞系为亚三倍体核型,共发现26种染色体异常,其中重复出现的染色体异常改变为染色体4、9、18、19、22、Y、10p、15p、8p、6q和12p缺失,染色体7和12q增加,以及染色体结构畸变der(9;15)(q10;q10)、der(10)(3;10)(?;q26)和der(12)(8;12)(?;p13).EGFR-FISH阳性为4/10.结论 胰腺癌细胞系的染色体重排非常复杂,进一步扩大样本量进行相关分析,包括了解胰腺癌的EGFR-FISH阳性率非常有必要.     

应用光谱染色体核型分析技术研究胰腺癌细胞系P2染色体核型

目的 探讨胰腺癌的细胞遗传学特征.方法 采用光谱核型分析技术对中国人胰腺癌细胞系P2的染色体核型进行分析,并选择EGFR/CEP 7双色荧光原位杂交(FISH)探针,对比分析10例胰腺癌和10例慢性胰腺炎石蜡标本的EGFR基因拷贝数,验证光谱核型分析结果.结果 P2细胞系为亚三倍体核型,共发现26种染色体异常,其中重复出现的染色体异常改变为染色体4、9、18、19、22、Y、10p、15p、8p、6q和12p缺失,染色体7和12q增加,以及染色体结构畸变der(9;15)(q10;q10)、der(10)(3;10)(?;q26)和der(12)(8;12)(?;p13).EGFR-FISH阳性为4/10.结论 胰腺癌细胞系的染色体重排非常复杂,进一步扩大样本量进行相关分析,包括了解胰腺癌的EGFR-FISH阳性率非常有必要.     

利用多平台遗传学技术产前诊断一罕见的含der(6)t(6;22)(q27;q11.2)的非罗氏易位及其随访

目的对一对平衡易位携带者夫妇,利用多平台遗传学技术进行产前诊断,并随访。方法对夫妇双方行染色体核型分析,对羊水细胞行核型分析、染色体微阵列分析(CMA)、荧光原位杂交(FISH),并以新生儿脐血对各检测进行复核;对新生儿随访至1周岁。结果父亲核型为46,XY,t(6;22)(q27;q11.2),母亲为46,XX;胎儿核型为45,XY,der(6)t(6;22)(q27;q11.2)pat,-22,CMA结果显示未测到有临床意义的拷贝数变异,FISH结果显示6号端粒区、22号端粒区和22q11.21区信号无增加或缺失;脐血复查结果与先前相同;对新生儿随访显示生命里程碑节点均正常。结论合理应用多平台遗传学技术,对产前诊断罕见病例十分重要。     

Inv(Y)患者精子染色体荧光原位杂交分析

目的 探讨Y染色体臂间倒位患者精子减数分裂形成中性染色体的分离规律.方法 采用G带、C带及荧光原位杂交(fluorescence in situ hybridization,FISH)对中期分裂相进行分析.应用三色探针CEPX、Tel Xp/Yp、Tel Xq/Yq对5例inv(Y)(p11.1q11.2)患者精子进行FISH,同时以染色体正常男性的正常精液作为对照.结果 5例inv(Y)(p11.1q11.2)精于性染色体数目及重组Y染色体异常率与对照组比差异无统计学意义.结论 inv(Y)(p11.1q11.2)患者精子无明显性染色体数目与结构异常,精子FISH分析可为其提供更准确的遗传咨询及指导植入前遗传学诊断.     

Array-CGH characterization of a prenatally detected de novo 46,X,der(Y)t(X;Y)(p22.3;q11.2) in a male fetus

We report on an apparently normal 5-month-old boy with a X;Y complex rearrangement identified first on prenatal diagnosis and found on array-CGH to have a 7.6?Mb duplication of Xp22.3 chromosome and a deletion of Yq chromosome, distal to the AZFa locus. Karyotype analysis on amniotic fluid cell cultures revealed a de novo homogenous chromosome marker that we interpreted as an isochromosome Yp. FISH analysis using SRY probe revealed only one signal on the derivative Y chromosome. The final karyotype was interpreted as 46,X,der(Y)t(X;Y)(p22.31;q11.22). Translocation Xp22;Yq11 in male are very rare event and only 4 cases have been published, all showing mental retardation and malformations. Herein we discussed some possible explanation for this apparent phenotypic variability.     

A synovial sarcoma with a complex t(X; 18;5;4) and a break in the ornithine aminotransferase (OAT)LI cluster on Xp11.2

The initial cytogenetic analysis of a biphasic synovial sarcoma revealed complex anomalies involving six different chromosomes: 46,Y,t(X185;4)(p11;q11;p13;q12),t(2;5)(q35;q11). After fluorescence in situ hybridization (FISH) analysis, using chromosome X-specific plasmid library and YAC probes, the situation appeared to be even more complex, with an insertion of part of the X chromosome short arm into the der(5)t(5;18). In spite of these complex chromosomal rearrangements, the Xp11 breakpoint could be mapped to within the ornithine aminotransferase (OAT)LI cluster, very similar to that reported previously for the standard t(X 18)(p11;q11) in synovial sarcomas. These findings suggest common pathogenetic pathways in these cytogenetically different but morphologically similar tumors. Genes Chrom Cancer 9:288-291 (1994). © 1994 Wiley-Liss, Inc.     

Molecular studies of an X;Y translocation chromosome in a woman with deletion of the pseudoautosomal region but normal height

A translocation chromosome in a woman with the karyotype 46,X,der(X)t(X;Y)(p22.3; q11.2) was investigated by FISH and STS analysis with molecular probes derived from the sex chromosomes. Due to the partial deletion of the short arm pseudoautosomal region (PARI) from DXYS14 to DXYS147 in the translocation chromosome, the proband is hemizygous for the gene responsible for growth control ( SS ) located in this region, yet does not show growth retardation. Molecular analysis of the Yq arm of the translocation chromosome revealed the presence of markers DYS273 to DYS246 harboring the hypothesized growth control gene critical region ( GCY ) on Yq, thereby placing the deletion breakpoint between markers DYS11 and DYS273. These results suggest that the Y-specific growth gene GCY on Yq compensates for the missing growth gene SS on Xp22.3.     

Molecular cytogenetic investigations in a novel complex variant of t(8;21)(q22;q22) with ins(15;21)(q15;q22.2q22.3) in a patient with AML-M2 subtype

Acute myeloid leukemia (AML) is a clinically and molecularly heterogeneous disease characterized by the aberrant proliferation of myeloid stem cells, reduced apoptosis and blockage in cellular differentiation. The present report describes the results of hematological, cytogenetic, and fluorescence in situ hybridization (FISH) analysis in a 25-year-old man diagnosed with AML-M2. Cytogenetic as well as FISH analysis revealed a complex translocation involving four chromosomes, with the karyotype 45,−Y,der(X)t(X;8)(p21;q22),der(8)t(8;21)(q22;q22),ins(15;21)(q15;q22.2q22.3),der(21)t(8;21)(q22;q22). The breakpoints at 8q22 and 21q22 suggested a rearrangement of the RUNX1T1 (alias ETO) and RUNX1 (previously AML1) genes, respectively. Using a dual-color FISH test with RUNX1T1 and RUNX1 probes, we demonstrated an RUNX1/RUNX1T1 fusion signal on the derivative chromosome 8, establishing this translocation as a novel complex variant of t(8;21)(q22;q22).     

Deletion of RBM and DAZ in azoospermia: Evaluation by PRINS

Molecular and cytogenetic studies from infertile men have shown that one or more genes controlling spermatogenesis are located in proximal Yq11.2 in interval 6 of the Y chromosome. Microdeletions within the azoospermia factor region (AZF) are often associated with azoospermia and severe oligospermia in men with idiopathic infertility. We evaluated cells from a normal‐appearing 27‐year‐old man with infertility and initial karyotype of 45,der(X)t(X;Y)(p22.3;p11.2)[8]/46,t(X;Y)(p22.3;p11.2)[12]. By fluorescence in situ hybridization with dual‐color whole chromosome paint probes for X and Y chromosomes, we confirmed the Xp‐Yp interchange. By primed in situ labeling, we identified translocation of the SRY gene from its original location on Yp to the patient's X chromosome at band Xp22. We also obtained evidence that the apparent marker was a der(Y) (possibly a ring) containing X and Y domains, and observed that the patient's genome was deleted for RBM and DAZ, two candidate genes for AZF. © 2001 Wiley‐Liss, Inc.     

Deletion of RBM and DAZ in azoospermia: evaluation by PRINS.

Molecular and cytogenetic studies from infertile men have shown that one or more genes controlling spermatogenesis are located in proximal Yq11.2 in interval 6 of the Y chromosome. Microdeletions within the azoospermia factor region (AZF) are often associated with azoospermia and severe oligospermia in men with idiopathic infertility. We evaluated cells from a normal-appearing 27-year-old man with infertility and initial karyotype of 45,der(X)t(X;Y)(p22.3;p11.2)[8]/46,t(X;Y)(p22.3;p11.2)[12]. By fluorescence in situ hybridization with dual-color whole chromosome paint probes for X and Y chromosomes, we confirmed the Xp-Yp interchange. By primed in situ labeling, we identified translocation of the SRY gene from its original location on Yp to the patient's X chromosome at band Xp22. We also obtained evidence that the apparent marker was a der(Y) (possibly a ring) containing X and Y domains, and observed that the patient's genome was deleted for RBM and DAZ, two candidate genes for AZF.     

Beckwith-Wiedemann syndrome due to 11p15.5 paternal duplication associated with Klinefelter syndrome and a "de novo" pericentric inversion of chromosome Y

We report on an infant who had been prenatally diagnosed with Klinefelter syndrome associated with a "de novo" pericentric inversion of the Y chromosome. A re-evaluation at 3 years of age suggested that he was also affected by Beckwith-Wiedemann syndrome (BWS). Karyotype was repeated and fluorescence in situ hybridisation (FISH) analysis revealed trisomy for 11p15.5-->11pter and a distal monosomy 18q (18q23-->qter). Parental cytogenetic studies showed that the father carried a balanced cryptic translocation between chromosomes 11p and 18q. Furthermore, the child had an extra X chromosome and a "de novo" structural abnormality of chromosome Y. Thus, his karyotype was 47,XX, inv (Y) (p11.2 q11.23), der(18) t (11;18) (p15.5;q23) pat. ish der(18) (D11S2071+, D18S1390-). Two markers on the X chromosome showed that the extra X of the child was paternally inherited. No deletions were observed on the structurally abnormal Y chromosome from any of the microsatellites studied. Clinical findings of patients with BWS due to partial trisomy 11p reveal that there is a distinct pattern of dysmorphic features associated with an increased incidence of mental retardation when comparing patients with normal chromosomes. This fact reinforces that FISH study have to be performed in all BWS patients, specially in those with mental retardation since small rearrangements cannot be detected by conventional cytogenetic techniques.     

Short stature in a mother and daughter caused by familial der(X)t(X;X)(p22.1-3;q26)

Deletions of the terminal Xp regions, including the short-stature homeobox (SHOX) gene, were described in families with hereditary Turner syndrome and Léri-Weill syndrome. We report on a 10-2/12-year-old girl and her 37-year-old mother with short stature and no other phenotypic symptoms. In the daugther, additional chromosome material was detected in the pseudoautosomal region of one X chromosome (46,X,add(Xp.22.3)) by chromosome banding analysis. The elongation of the X chromosome consisted of Giemsa dark and bright bands with a length one-fifth of the size of Xp. The karyotype of the mother demonstrated chromosome mosaicism with three cell lines (46,X,add(X)(p22.3) [89]; 45,X [8]; and 47,X,add(X)(p22.3), add(X)(p22.3) [2]). In both daughter and mother, fluorescence in situ hybridization (FISH), together with data from G banding, identified the breakpoints in Xp22.1-3 and Xq26, resulting in a partial trisomy of the terminal region of Xq (Xq26-qter) and a monosomy of the pseudoautosomal region (Xp22.3) with the SHOX gene and the proximal region Xp22.1-3, including the steroidsulfatase gene (STS) and the Kallmann syndrome region. The derivative X chromosome was defined as ish.der(X)t(X;X)(p22.1-3;q26)(yWXD2540-, F20cos-, STS-, 60C10-, 959D10-, 2771+, cos9++). In daughter and mother, the monosomy of region Xp22.1-3 is compatible with fertility and does not cause any other somatic stigmata of the Turner syndrome or Léri-Weill syndrome, except for short stature due to monosomy of the SHOX gene.