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.     

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.     

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。     

羊膜穿刺检出一例母系遗传的X;Y易位

这是一个X;Y易位的病例,包括整个Yp和着丝粒以及Xp22.3→pter的缺失.G显带分析揭示断裂点位于Xp22.3和Yq11.2.QFQ和CBG显带证实存在Yq异染色质区,Y染色体着丝粒无受抑制的证据.这位妇女及她的胎儿携有相同的不平衡易位性染色体[(46,X,t(X;Y)(p22.3;q11.2)],并具有正常的女性表型.易位造成了Xp22.3→pter的缺失,结果导致部分Xp单体.这位妇女表现出类似Turner综合征的皮肤纹理改变(三叉点t″,TRC为198)和不相称的身材矮小,以及H-Y抗原滴定度阳     

三例畸变Y染色体的重组形式及定位分析

目的 对3例畸变Y染色体进行定位分析并确定其重组形式.方法 采用染色体G显带、多重连接依赖探针扩增(multiplex ligation dependent probe amplification,MLPA)、荧光原位杂交(fluorescence in situ hybridization,FISH)、Y染色体多个序列标签位点(sequence tagged site,STS)及Illumina人类全基因组单核苷酸多态性芯片扫描(single nucleotide polymorphisms array,SNP-array)等多种技术.结果 3例患者染色体G显带核型均为46,X,+ mar.MLPA检测发现例1 SRY、ZFY、UTY基因重复;例2 SRY、ZFY基因重复、UTY基因缺失;例3X染色体短臂/Y染色体短臂(X/Yp)、X染色体长臂/Y染色体长臂(X/Yq)亚端粒区域基因拷贝数减少.Y染色体STS分析提示:例1的SRY及Y染色体AZFa区sY84、sY86、AZFb区sY1227存在,但sY1228及AZFc区多个STS缺失,断裂点位于AZFb区sY1227和sY1228之间;例2的SRY及着丝粒区域sY1200存在,其余STS均缺失;例3的SRY及AZF多个STS均存在.SNP-array扫描提示,例1 Yp11.31-p11.2区重复,Yq11.22-q11.23区缺失,缺失片段约为5.18 Mb;例2 Yp11.31-p11.2区重复,重复片段为3.724 Mb,Yq11.21-q11.23区域缺失,缺失约14.644Mb;例3 X/Yp亚端粒区域(PAR) p22.33单拷贝缺失,X/Yq亚端粒区域(PAR) q28单拷贝缺失.FISH分析提示,例1和例2细胞中期原位杂交核型均为46,X,+ mar.ish(Y)(SRY++,DYZ3++,DYZ1-).综合分析:例1和例2的标记染色体均为短臂等臂双着丝粒Y染色体.分子核型:例1为46,X,idic (Y)(q11.23);例2为46,X,idic(Y) (q10);例3为标记染色体为环状Y,核型为46,X,r(Y)(p1 1q12).结论 Y染色体畸变形式多样,选用MLPA、Y染色体STS、FISH、SNP-array等多项技术联合诊断是确定其断裂点及重组形式的重要手段.     

一例性发育异常患儿的遗传学分析CSCD

目的探讨1例性发育异常(disorders of sex development,DSD)患儿的致病原因。方法应用染色体核型分析技术、荧光原位杂交(fluorescence in situ hybridization,FISH)技术、染色体微阵列分析(chromosomal microarray analysis,CMA)技术和性腺组织病理活检技术对患儿进行遗传学检测及致病原因探讨。结果综合各种检测技术,患儿分子细胞核型分析结果为46,X,psu idic(Y)(p11.32)[72]/45,X[28].ish psu idic(Y)(p11.32)(SRY++,DYZ3++).arr[hg19]Yp11.32(118552-512055)×0,Yp11.32p11.31(515916-2640819)×1-2,Yq12(59055438-59336104)×1-2,Yp11.31q11.23(2650425-28799654)×1-2。CMA结果显示在Y染色体短臂的拟常染色体区域1(PAR1)末端存在393.5 kb片段的缺失;约50%的细胞在PAR1区域(Yp11.32p11.31)存在2.1 Mb片段的重复;约50%的细胞在Y染色体Yp11.31q11.23区域存在26.1 Mb片段的重复;约50%的细胞在PAR2区域存在280.6 kb片段的重复。结论46,X,psu idic(Y)(p11.32)[72]/45,X[28]嵌合核型是导致患儿性发育异常的原因。     

一例性发育异常患儿的遗传学分析

目的探讨1例性发育异常(disorders of sex development, DSD)患儿的致病原因。方法应用染色体核型分析技术、荧光原位杂交(fluorescencein situ hybridization, FISH)技术、染色体微阵列分析(chromosomal microarray analysis, CMA)技术和性腺组织病理活检技术对患儿进行遗传学检测及致病原因探讨。结果综合各种检测技术, 患儿分子细胞核型分析结果为46, X, psu idic(Y)(p11.32)[72]/45, X[28]. ish psu idic(Y)(p11.32)(SRY++, DYZ3++). arr[hg19] Yp11.32(118 552-512 055)×0, Yp11.32p11.31(515 916-2 640 819)×1-2, Yq12(59 055 438-59 336 104) ×1-2, Yp11.31q11.23(2 650 425-28 799 654)×1-2。CMA结果显示在Y染色体短臂的拟常染色体区域1(PAR1)末端存在393.5 kb片段的缺失;约...     

产前诊断中FISH鉴定染色体平衡易位来源研究

目的探讨利用FISH鉴定染色体平衡易位及其来源在产前诊断中的应用。方法常规羊水细胞培养和染色体制备分析,最后采用荧光原位杂交技术进行鉴定。结果常规G显带(320条带)下分析胎儿的染色体核型为46,XX,?17q25mat;最后FISH鉴定为ish der(11)t(11;17)(p14.3;q25)(11pter-,17qter+,11qter+)mat,der(17)t(11;17)(p14.3;q25)(17pter+,17qter-,11pter+)mat。结论 FISH能够弥补常规G显带条件下对亚显微结构异常难以鉴定的不足,以明确胎儿染色体结构异常的来源。     

两例分别由父源性平衡易位和母源性插入易位导致8p部分三体智力低下患儿的临床表型和遗传学分析

目的 明确两例智力低下患儿8号染色体短臂异常性质和来源,分析其染色体改变与表型的相关性.方法 首先应用常规G显带分析2例患儿及父母外周血染色体改变,然后应用比较基因组杂交芯片(array comparative genomic hybridization,array CGH)对其中1例常规核型分析的结果进行精确定位.结果 例1母亲的染色体改变为8p和3q的平衡插入易位,该患儿继承了母亲的1条衍生3号染色体,核型为46,XX,der(3) inv ins (3;8)(q25.3;p23.1p11.2)mat,导致8p部分三体.Array CGH分析显示重复区域为8p11.21-8p22,片段大小为26.9 Mb,该患儿主要表现为智力低下,未见其他8p三体的典型临床特征.例2父亲的核型为8p和11q的平衡易位,该患儿继承了父亲的1条衍生11号染色体,核型为46,XX,der(11)t(8;11)(p11.2;q25)pat,临床表现为智力低下,特殊面容,同时伴有先天性心脏病和骨骼异常,与典型8p三体表型相似,但面容特征不典型.结论 8p部分三体是2例患儿异常表型的主要原因,但与典型的8p三体相比,表型存在异质性;父母染色体分析可以帮助明确易位的性质从而有利于再发风险评估;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.

Abstract：

Objective To determine the origin of aberrant chromosomes involving the short arm of chromosome 8 in two mentally retarded children, and to correlate the karyotype with abnormal phenotype. Methods Routine G-banding was performed to analyze the karyotypes of the two patients and their parents, and array comparative genomic hybridization (array CGH) was used for the first patient for fine mapping of the aberrant region. Results The first patient presented with only mental retardation. The father had normal karyotype. The mother had an apparent insertion translocation involving chromosomes 8 and 3 [46,XX, inv ins (3;8) (q25.3;p23.1p11.2)], the karyotype of the child was ascertained as 46,XX,der(3) inv ins (3;8)(q25.3;p23.1p11.2). Array CGH finely mapped the duplication to 8p11.21-8p22, a 26.9Mb region. The other patient presented with mental retardation, craniofacial defects, congenital heart disease and minor skeletal abnormality. The mother had normal karyotype. The father had an apparently balanced translocation involving chromosome 8p and 11q, the karyotype was 46,XY, t(8;11)(p11.2;q25). The karyotype of the child was then ascertained as 46,XX,der(11)t(8;11)(p11.2;q25). Conclusion These results suggested that partial trisomy 8p was primary cause for the phenotypic abnormalities of the two patients, whereas a mild phenotypic effect was observed in patient 1. Parental karyotype analysis could help define the aberrant type and recurrent risk evaluation. In contract to routine karyotype analysis, aberrant regions could be mapped by array CGH with higher resolution and accuracy.     

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.