150例无精子症患者的染色体核型分析

目的通过对无精子症患者行染色体核型分析,探讨无精子症与染色体异常的关系。方法对150例无精子症患者行G显带核型分析,分析染色体异常的类别及其导致无精子症的原因。结果 150例无精子症患者共检出异常核型30例,异常检出率为20.0%。异常核型中数目异常有20例,占异常核型的66.7%(20/30),全部为47,XXY;结构异常有10例,占异常核型的33.3%(10/30),其中罗氏易位45,XY,der(13;14)有3例、常染色体相互易位46,XY,t(6;15)(p21.2;q26)和46,XY,t(3;4)(p13;p14)各1例、Y染色体和常染色体相互易位46,X,t(Y;13)(q12;q22)有1例、大Y染色体46,X,Yqh+有3例、Y倒位46,X,inv(Y)(p11q12)有1例。结论染色体异常是导致无精子症的重要原因,对无精子症患者有必要行染色体核型分析,如果有条件还可以对染色体正常及Y染色体结构异常的无精子症患者做Y染色体微缺失检查,进一步查明无精子症的原因。     

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.     

人类额外小标记染色体的鉴定及其研究价值的探讨

目的 应用荧光原位杂交(fluorescent in situ hybridization,FISH)结合染色体核型分析了解人类额外小标记染色体(small supernumerary marker chromosomes,sSMC)的来源,并探讨其发生机理及应用价值.方法 对3例羊水染色体核型分析结果显示是47,XN,+mar的胎儿羊水细胞用两种探针cepFISH(针对着丝粒)和SubcenM-FISH(针对近着丝粒区域)进行分析.结果 病例1的FISH结果为47,XY,+mar.ish inv dup(22) (q11.1)(D22Z4++,D14/22Z1+,RP11-172D7-),标记染色体完全由异染色质组成,胎儿活产未见异常临床表型.病例2的FISH结果为47,XX,+mar.ish r(10) (p11.2q11.2)(cep10+,RP11 232C13+,RP11-178A10+)[25]/46,XX[10],标记染色体由着丝粒附近的常染色质和异染色质组成,胎儿活产无异常临床表型.病例3的FISH结果为47,XY,+mar.ish inv dup(22) (q11.1)(D22Z4+,D14/22Z1+),标记染色体由异染色质组成,胎儿B超有异常但与此标记染色体关系不明.结论 由于sSMC来源的多样性,给产前诊断带来了巨大的困难.其鉴定需要在传统的显带核型分析基础上结合FISH或者其他分子技术.其特殊的结构也为基因定位、异染色质研究以及基因治疗等提供了非常有价值的研究载体.     

四例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学研究

目的 探讨4例合并继发性der(9)t(9;22)(q34;q11)inv(9)(p22q34)异常的Ph阳性白血病的临床及分子遗传学特征.方法 应用骨髓细胞直接法或短期培养法制备染色体,经R显带进行核型分析.应用BCR/ABL双色双融合探针和9号染色体短臂及长臂涂染探针分别对4例伴有inv(9)(p22q34)的Ph阳性患者标本进行荧光原位杂交(fluorescence in situ hybridization,FISH)和染色体涂染分析.用逆转录PCR检测BCR/ABL融合基因转录本.结果 1例急性髓细胞白血病患者核型中有3种克隆,分别为正常细胞、t(9;22)(q34；q11)异常细胞、同时合并der(9)t(9;22)衍生克隆和Ph以及其它异常,即t(8;12)(q12;p11),der(9) t(9；22)inv(9) (p22q34),der(22)t(9；22)细胞.其余3例慢性粒细胞白血病患者均同时合并Ph和der(9)t(9;22)(q34；q11)inv(9)(p22q34).FISH结果显示,3例有1红1绿两个融合信号、2红2绿1个融合信号、且在中期分裂相中发现1红1绿荧光信号分别位于9号染色体的两端；另1例67.5％的细胞有2红1绿1融合信号,有1绿色信号的缺失即表明BCR基因的缺失.染色体涂抹检测发现4例患者均有9号染色体的倒位.逆转录PCR检测均为b3a2转录本.该继发异常既可发生于Ph阳性CML慢性期或急变期,也可发生于原发性Ph阳性AML.该异常核型可能与预后不良相关.结论 合并继发性der(9)t(9;22)(q34；q11)inv(9)(p22q34)异常的Ph阳性白血病是一种少见但可再现的Ph继发性异常,具有独特的临床和分子遗传学特点.     

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.     

常染色体异常与无精子症的关系(附2例世界首报异常核型)

应用外周血染色体常规制片方法对睾丸无明显损伤史的24例无精子症患者进行染色体分析发现常染色体异常8例占33.3%,其中常染色体相互易位5例,占20.8%,2例为世界首报异常核型,[46,XY,t(11;13)(p10;q10);46,XY,t(1;2)(p22;p23)].性染色体异常5例,占20.8%,正常核型11例,占45.8%.     

Y染色体倒位对男性生殖的影响

目的 对有不良生育史或原发不育的3200例男性进行细胞遗传学检查以及无精子因子(azoospermia factor,AZF)微缺失分析.方法 外周血淋巴细胞培养,常规制备染色体标本,G显带,必要时进行C显带.对具有Y染色体臂间倒位[inv(Y)]合并精子计数＜15×106/mL者进行AZF区微缺失检测.结果 共检出22例inv(Y),占全部患者的0.69％,所涉及的断裂点位于Yp11.1和Yq11.2.在22例inv(Y)中包括20例46,X,inv(Y),患者表型、第二性征均正常,其中12人妻子曾流产1～4次,4人妻子有死胎、死产或胎儿多发畸形史,4人临床诊断为男性原发不育.另外2例47,XX,inv(Y)患者临床表现类似典型的Klinefelter综合征.在5例inv(Y)合并精子计数＜15×106/mL的患者中,发现1人具有AZF-c(sY254)缺失.结论 Inv(Y)对男性生殖有一定的影响.若未涉及生精相关基因,且携带者表型正常,可将其视为多态,但仍需加强对其妻子妊娠时的产前诊断.对于携带inv(Y)并具有生精障碍者,应慎重进行单精子卵泡内注射技术.     

性染色体非整倍体合并罗氏易位患者的遗传学分析

目的应用细胞遗传学和分子生物学技术分析1例少弱精子患者的核型,确定其少弱精子的原因。方法应用实验室常规染色体标本制备方法进行G-显带和C-显带,并应用Yq12区DYZ1探针和Yp11.1-q11.1区DYZ3探针与病例的中期分裂相进行荧光原位杂交(fluorescence in situ hybridization,FISH),同时对患者进行了Y染色体微缺失的检测。结果结合G-显带、C-显带和FISH检测结果,确定该患者核型为46,XYY,dic(13,22)(p11.1;p11.1)。Yq11区生精基因微缺失检测未发现该患者存在缺失。结论细胞遗传学检测结合FISH可以明确诊断复杂的染色体异常,为患者提供正确的遗传咨询和生育指导。     

染色体倒位核型二例

例1 女,27岁,表型正常.婚后1年,因其夫唇裂来我院进行遗传咨询.细胞遗传学检查:常规外周血淋巴细胞培养、染色体制备、G显带分析,计数30个分裂相,镜下分析5个,患者核型为46,XX,inv(2)(pter-p11.2::q14.2→p11.2::q14.2→qter).患者丈夫染色体核型正常,父母染色体未查.     

Meiotic segregation analysis in a t(4;8) carrier: comparison of FISH methods on sperm chromosome metaphases and interphase sperm nuclei.

Meiotic segregation of a t(4;8)(q28;p23) translocation carrier was determined by two different methods to compare the final results. A total of 352 sperm chromosome complements, obtained after human-hamster in vitro fertilisation, were analysed by whole chromosome painting, and 6590 sperm heads were studied by fluorescence in situ hybridisation (FISH). Frequencies of alternate, adjacent I, adjacent II and 3 : 1 segregations were, for sperm chromosomes, 35.5, 33.2, 19.9 and 11.3% respectively. For sperm head analysis, results were 30.5, 28.5, 20.5 and 19.5% respectively. There were no statistically significant differences between the two methods with respect to the observed frequencies of sperm with balanced and unbalanced chromosome constitutions. Among unbalanced gametes, the methods differed only in the frequency of 3 : 1 segregation (chi(2), P<0.0001). Different factors that could explain this result are discussed. To determine possible interchromosomal effects, multicolour FISH was used on sperm heads. Disomy rates of sex and 18 chromosomes were higher in the translocation carrier than in the control. The differences observed were statistically significant (P<0.0001 for chromosomes X and 18, and P=0.0091 for chromosome Y).     

Cytogenetic analysis of sperm chromosomes and sperm nuclei in a male heterozygous for a reciprocal translocation t(5;7)(q21;q32) by in situ hybridisation

We have studied the meiotic segregation of a reciprocal translocation t(5;7)(q21;q32) in a male carrier, using the human sperm-hamster oocyte fusion technique and the whole chromosome painting. A total of 296 sperm complements were analysed by dual chromosome painting. The frequencies of alternate, adjacent-1, adjacent-2 and 3:1 segregation were 49.7%, 32.4%, 16.2% and 1.7% respectively. Aneuploidy frequencies for chromosomes not involved in the translocation were determined by FISH on decondensed sperm heads using probes from chromosomes X, Y, 6, 18 and 21. A total of 20,118 spermatozoa was analysed, 10,201 by two-colour FISH (probes for chromosomes 6 and 21) and 9917 by three-colour FISH (probes for chromosomes X, Y, and 18). There was no evidence of an interchromosomal effect, since disomy frequencies were within the range of normal controls.     

Intrachromosomal insertion translocation resulting in duplication of chromosome band Yq11.2 in two fertile brothers

Chromosome analysis in a couple referred because of two spontaneous abortions showed a normal 46,XX karyotype in the 28-year-old female and an aberrant Y chromosome with an enlarged short arm in the 30-year-old male. Subsequent chromosome analysis showed that his 33-year-old brother was carrier of the same Y chromosome aberration. Further characterization of the aberrant Y chromosome with FISH using probes specific for chromosome bands Yp11.32, Yq11.2, the centromere and the subtelomeric region of the p-arm of the Y chromosome showed that chromosome band Yq11.2 was duplicated and inserted in the p-arm of the Y chromosome. Combining the results of the analysis of GTG-banded chromosomes and of the FISH analysis we conclude that both patients have a 46,X,ins dup(Y)(pter --> p11.23::q12 --> q11.1::p11.23 -->) karyotype. The clinical and cytogenetical findings are reported and discussed.     

Sperm aneuploidy and meiotic sex chromosome configurations in an infertile XYY male

BACKGROUND: There is little information regarding the behaviour of the extra Y chromosome during meiosis I in men with 47,XYY karyotypes and the segregation of the sex chromosomes in sperm. We applied immunofluorescent and FISH techniques to study the relationship between the sex chromosome configuration in meiotic germ cells and the segregation pattern in sperm, both isolated from semen samples of a 47,XYY infertile man. METHODS: The sex chromosome configuration of pachytene germ cells was determined by immunostaining pachytene nuclei for synaptonemal complex protein 3 (SCP3) and SCP1. FISH was subsequently performed to identify the sex chromosomes and chromosome 18 in pachytene cells. Dual- and triple-color FISH was performed on sperm to analyse aneuploidy for chromosomes 13, 18, 21, X, and Y. RESULTS: 46,XY/47,XYY mosaic pachytene cells were observed (22.2% vs. 77.8%, respectively). The XYY trivalent, and X+YY configurations were most common. While the majority of sperm were of normal chromosomal constitution, an increase in sex and autosome disomy was observed. CONCLUSIONS: The level of germ cell moscaicism and their meiotic sex chromosome configurations may determine sperm aneuploidy rate and fertility status in 47,XYY men. Our approach of immunostaining meiotic cells in the ejaculate is a novel method for investigating spermatogenesis in infertile men.     

Clinical and molecular‐cytogenetic studies in seven patients with ring chromosome 18

We report the results of detailed clinical and molecular‐cytogenetic studies in seven patients with ring chromosome 18. Classical cytogenetics and fluorescence in situ hybridization (FISH) analysis with the chromosome 18 painting probe identified five non‐mosaic and two complex mosaic 46,XX,dup(18)(p11.2)/47,XX,dup(18)(p11.2),+r(18) and 46,XX,dup(18)(p11.32)/47,XX,dup(18)(p11.32),+r(18) cases. FISH analysis was performed for precise characterization of the chromosome 18 breakpoints using chromosome 18–specific short‐arm paint, centromeric, subtelomeric, and a panel of fifteen Alu‐ and DOP‐PCR YAC probes. The breakpoints were assessed with an average resolution of ∼2.2 Mb. In all r(18) chromosomes, the 18q terminal deletions ranging from 18q21.2 to 18q22.3 (∼35 and 9 Mb, respectively) were found, whereas only in four cases could the loss of 18p material be demonstrated. In two cases the dup(18) chromosomes were identified as inv dup(18)(qter→p11.32::q21.3→qter) and inv dup(18)(qter→p11.32::p11.32→p11.1: :q21.3→qter)pat, with no evidence of an 18p deletion. A novel inter‐intrachromatid mechanism of formation of duplications and ring chromosomes is proposed. Although the effect of “ring instability syndrome” cannot be excluded, the phenotypes of our patients with characteristic features of 18q‐ and 18p‐ syndromes are compared and correlated with the analyzed genotypes. It has been observed that a short neck with absence of cardiac anomalies may be related to the deletion of the 18p material from the r(18) chromosome. © 2001 Wiley‐Liss, Inc.     

Clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18.

We report the results of detailed clinical and molecular-cytogenetic studies in seven patients with ring chromosome 18. Classical cytogenetics and fluorescence in situ hybridization (FISH) analysis with the chromosome 18 painting probe identified five non-mosaic and two complex mosaic 46,XX,dup(18)(p11.2)/47,XX,dup(18)(p11.2),+r(18) and 46,XX,dup(18)(p11.32)/47,XX,dup(18)(p11.32),+r(18) cases. FISH analysis was performed for precise characterization of the chromosome 18 breakpoints using chromosome 18-specific short-arm paint, centromeric, subtelomeric, and a panel of fifteen Alu- and DOP-PCR YAC probes. The breakpoints were assessed with an average resolution of approximately 2.2 Mb. In all r(18) chromosomes, the 18q terminal deletions ranging from 18q21.2 to 18q22.3 ( approximately 35 and 9 Mb, respectively) were found, whereas only in four cases could the loss of 18p material be demonstrated. In two cases the dup(18) chromosomes were identified as inv dup(18)(qter-->p11.32::q21.3-->qter) and inv dup(18)(qter-->p11.32::p11.32-->p11.1: :q21.3-->qter)pat, with no evidence of an 18p deletion. A novel inter-intrachromatid mechanism of formation of duplications and ring chromosomes is proposed. Although the effect of "ring instability syndrome" cannot be excluded, the phenotypes of our patients with characteristic features of 18q- and 18p- syndromes are compared and correlated with the analyzed genotypes. It has been observed that a short neck with absence of cardiac anomalies may be related to the deletion of the 18p material from the r(18) chromosome.     

Cytogenetic, molecular and testicular tissue studies in an infertile 45,X male carrying an unbalanced (Y;22) translocation: case report

(Y;autosome) translocations have been reported in association with male infertility. Different mechanisms have been suggested to explain the male infertility, such as deletion of the azoospermic factor (AZF) on the long arm of the Y chromosome, or meiosis impairment. We describe a new case with a de novo unbalanced translocation t(Y;22) and discuss the genotype-phenotype correlation. A 36 year old male with azoospermia was found to have a mosaic 45,X/46,X, + mar karyotype. Fluorescence in situ hybridization (FISH) showed the presence of a derivative Y chromosome containing the short arm, the centromere and a small proximal part of the long-arm euchromatin of the Y chromosome and the long arm of chromosome 22. The unstable small marker chromosome included the short arm and the centromere of chromosome 22. This unbalanced translocation t(Y;22)(q11.2;q11.1) generated the loss of the long arm of the Y chromosome involving a large part of AZFb, AZFc and Yq heterochromatin regions. Testicular tissue analyses showed sperm in the wet preparation. Our case shows the importance of documenting (Y;autosome) translocations with molecular and testicular tissue analyses.     

Three patients with 46,X,inv(Y)(p11.2q11.2)pat/45,X and their pedigree analysis

The present study aimed to perform chromosome examination and pedigree analysis on three patients with semen abnormality who had undergone in vitro fertilization–embryo transfer (IVF-ET). Peripheral blood cell culture and chromosome karyotyping were performed on 4,200 individuals who had undergone chromosome examination. Among them, 155 pregnant women who had successfully conceived were subjected to amniotic cell culture and chromosome karyotyping and those with abnormal chromosome karyotype were further subjected to C-banding and whole-genome sequencing. Mosaicism for a 46,X,inv(Y)(p11.2q11.2)pat/45,X karyotype was identified in the probands and immediate adult male relatives. The incidence of this mosaicism in the study population was only 0.07% (3/4,200), which is reported for the first time. For the proband of pedigree A, the results of whole-genome sequencing and other tests were normal, and the chromosome karyotype of IVF fetuses was 46,X,inv(Y)(p11.2q11.2)pat. All the male members of three pedigrees have normal phenotypes, with no features of Turner's syndrome (45,X) or hermaphroditism (45,X/46,XY), suggesting that the inverted Y chromosome is extremely unstable and particularly susceptible to loss in somatic cells. So we speculate this karyotype may be a unique type of inverted Y chromosome in somatic cells.