染色体平衡易位携带者妊娠风险及妊娠结局的研究

目的 探讨染色体平衡易位携带者的妊娠风险及其妊娠结局.方法 194例染色体平衡易位携带者,根据平衡易位种类分成相互易位（135例）、非同源罗伯逊易位（52例）、同源罗伯逊易位（7例）3组.调查携带者生育史并随访诊断平衡易位后的妊娠情况,比较各组自然流产、先天缺陷及正常（或）平衡易位后代概率.结果 （1）194对夫妇共妊娠503例次,其中自然流产411例次（81.7%,411/503）;产前诊断胎儿异常而终止妊娠16例次（3.2%,16/503）;活产缺陷儿36例次（7.2%,36/503）;正常（或）平衡易位后代40例次（8.0%,40/503）.（2）相互易位、非同源罗伯逊易位、同源罗伯逊易位3组,活产缺陷儿比率分别为5.7%（20/350）、10.9%（14/128）、8.0%（2/25）,3组间相互比较,差异有统计学意义（P＜0.05）;3组正常（或）平衡易位后代比率分别为6.6%（23/350）、13.3%（17/128）、0,3组间相互比较,差异有统计学意义（P＜0.05）;而3组自然流产及产前诊断胎儿异常终止妊娠比率比较,差异无统计学意义（P＞0.05）.（3）52例次先天缺陷中活产36例次（69%）,经产前诊断确诊后引产16例次（31%）.27例次先天缺陷获得细胞遗传学诊断,唐氏综合征发生率为59%（16/27）.（4）相互易位组和非同源罗伯逊易位组共有39对夫妇得到40个正常（或）平衡易位后代,同源罗伯逊易位组无正常（或）平衡易位后代.40个正常（或）平衡易位后代中26个获得产前细胞遗传学诊断,正常核型6个（23%）,平衡易位核型20个（77%）.结论 染色体平衡易位携带者自然妊娠风险大,尤其同源罗伯逊易位携带者难以获得染色体正常（或）平衡易位的后代.     

男性同源染色体罗伯逊易位1例

细胞遗传学研究表明,染色体平衡易位是习惯性流产的重要原因之一,但男性同源染色体罗伯逊易位致妻子习惯性流产报道不多.我们最近发现1例男性13/13同源染色体罗伯逊易位致配偶5次自发流产和继发不孕,现报道如下.患者男,39岁,23岁结婚以后,其配偶孕5产0,均于孕6个月内自然流产.1983年以来则继发不孕.     

121个染色体平衡易位携带者PGD周期COH的卵巢反应性分析

目的:探讨常染色体平衡易位对女性携带者控制性超促排卵(COH)中卵巢反应性的影响。方法:回顾分析于我院行胚胎植入前遗传学诊断(PGD)的109对常染色体平衡易位夫妇,共121个周期,其中夫妇中仅女方为平衡易位携带者56例(63个周期,研究组),包括罗伯逊易位携带者23例(27个周期),相互易位携带者33例(36个周期);夫妇中仅男方为平衡易位携带者53例(58个周期,对照组),包括罗伯逊易位携带者30例(32个周期),相互易位携带者23例(26个周期)。分析COH过程中,研究组和对照组的女方卵巢反应性指标和妊娠结局。结果:两组的女方年龄、体重指数(BMI)、基础内分泌及窦卵泡数(AFC)均无显著差异(P0.05)。两组的卵巢反应性指标,包括Gn总量、HCG注射日E2水平、获卵数、D3胚胎数、可移植胚胎数及移植胚胎数,以及移植周期临床妊娠率、早期流产率及种植率均无显著差异(P0.05)。单独就罗伯逊易位携带者或相互易位携带者而言,两组的各指标均无显著差异。排除可能影响COH卵巢反应性的女方因素,研究组与对照组的各指标均无显著差异。结论:染色体平衡易位,包括罗伯逊易位或相互易位并不影响COH中的卵巢反应性。应将染色体平衡易位女性携带者视为正常卵巢反应性,采用合适剂量的促性腺激素进行控制性促排卵。     

勘误

<正>本刊2014年第23卷第3期刊登的文章《121个染色体平衡易位携带者PGD周期COH的卵巢反应性分析》(P165-170)中1.1研究对象中"研究组纳入37例(41个周期,包括罗伯逊易位携带者17个周期和相互易位携带者22个周期),对照组为37例(41个周期,包括罗伯逊易位携带者24个周期和相互易位携带者19个周期)"应为"研究组纳入37例(41个周期,包括罗     

染色体易位的植入前遗传学诊断

目的 观察染色体平衡易位和罗伯逊(罗氏)易位基因携带者夫妇进行植入前遗传学诊断(PGD)后的胚胎染色体遗传特征和胚胎着床、妊娠情况,探讨PGD在染色体易位基因携带者夫妇实现正常生育中的意义.方法 用荧光原位杂交(FISH)技术对36对夫妇的胚胎进行PGD,其中14例为染色体平衡易位(平衡易位组),22例为染色体罗氏易位(罗氏易位组),并对诊断结果和胚胎着床、妊娠情况进行分析.结果 36例患者共活检胚胎253个,成功诊断胚胎225个,成功率为88.9%(225/253),获得可供移植的正常或平衡的胚胎共58个.平衡易位组和罗氏易位组PGD后胚胎着床率分别为36%(5/14)和14%(6/44),临床妊娠率分别为4/9和26%(5/19).结论 PGD可有效诊断胚胎染色体平衡易位和罗氏易位,避免反复流产和不必要的非意愿性终止妊娠,并获得理想的胚胎着床率和临床妊娠率.     

t(11;22)(q23;q11)复发性染色体平衡易位——4例病案报道及文献复习

目的:初步探讨非罗伯逊型复发性t(11;22)(q23;q11)染色体平衡易位的发生机制。方法:外周血染色体核型分析检测有不孕不育或不良生育史的4例患者的染色体核型。结果:4例t(11;22)(q23;q11)易位患者,染色体断裂位点一致,患者间无亲缘关系,均有不良生育史,其中2例女性表现为反复流产,2例男性患者表现为精子数目减少和活力下降的。结论:t(11;22)(q23;q11)是一种较为少见的非罗伯逊易位型复发性平衡易位,对t(11;22)(q23;q11)深入研究有助于进一步完善染色体畸变的理论基础。     

8880例遗传咨询病人的染色体分析

目的 探讨染色体异常在遗传咨询病人中的发生情况。方法 取受检者外周血进行淋巴细胞培养,常规收获制片,Ｇ显带处理,显微镜下进行核型分析。结果 在８８８０例病人中共检出染色体异常３７３例,染色体异常检出率为４．２０％,其中平衡易位１３１例（３５．１２％）,罗伯逊易位３１例（８．３１％）,倒位１２例（３．２２％）,性染色体异常１０８例（２８．９５％）,染色体不平衡９１例（２４．４０％）。结论妇产科许多疾     

76例羊水胎儿染色体结构异常临床分析

目的通过对妊娠中期孕妇羊水染色体结构异常产前诊断指征分布、发病率及妊娠结局的分析,探讨妊娠中期胎儿染色体结构异常的妊娠结局。方法对2011年2月至2015年3月2 562例羊水染色体检查中76例染色体结构异常孕妇的临床资料进行回顾性分析。结果 2 562例羊水标本中,检出76例(2.97%)染色体结构异常,其中染色体倒位29例,相互易位25例,不平衡易位11例,复杂重排5例,其他结构异常6例。76例患者中,55例患者选择继续妊娠,其中29例染色体倒位,23例相互易位,3例复杂重排;21例患者选择终止妊娠,其中染色体不平衡易位11例,复杂重排2例,其他结构异常6例,X与常染色体新发突变易位1例,遗传型易位伴Turner综合征1例。结论产前诊断中羊水染色体结构异常主要为染色体倒位、相互易位、不平衡易位及复杂重排。绝大部分相互易位及倒位的结构异常可以选择继续妊娠。不平衡易位及复杂重排由于涉及基因片段的增加或丢失,大部份选择终止妊娠。     

18例染色体异常核型女性供精人工授精结局分析

目的:探讨染色体核型异常对人工授精妊娠结局的影响。方法:回顾性分析因其配偶为特发性不育而接受供精人工授精(AID)治疗的1 300例正常女性,外周血淋巴细胞染色体G显带核型异常与供精人工授精治疗结局的关系。结果:检出异常核型18例(染色体异常发生率1.38%),包括平衡易位和罗伯逊易位各1例(0.08%),9号染色体臂间倒位9例(0.69%),其他7例(0.54%)。18例染色体核型异常患者术前检查显示其排卵正常,输卵管通畅,子宫及双侧附件均未见明显异常。AID治疗结果8例未孕,其中罗伯逊易位1例、臂间倒位3例、其他4例,10例妊娠成功。结论:因男性特发性不育患者,特别是进行辅助生殖治疗多个周期后仍未受孕的夫妇,对女方进行细胞遗传学检查是非常必要的。     

复发性流产夫妇的染色体结构异常分析

目的:探讨复发性流产与染色体结构异常的关系。方法:对有复发性自然流产史的112对夫妇进行外周血染色体核型分析。结果:112对夫妇中有20例染色体核型异常,异常检出率8.9％。其中平衡易位4例,复杂易位1例,臂间倒位8例,Y染色体变异6例,占2.7％;常染色体变异1例。结论:复发性流产夫妇任何一方的染色体结构异常均可引起流产等不良妊娠,9号染色体倒位和Y染色体变异与早期流产的关系密切。     

Embryo development characteristics in Robertsonian and reciprocal translocations: a comparison of results with non-translocation cases

The effect of translocations on embryo development was evaluated and results were compared in terms of embryo development with those of embryos obtained from standard intracytoplasmic sperm injection (ICSI) cycles. In 23 translocation carriers with 34 cycles, fertilization, pronuclear morphology scoring (PMS), developmental arrest, cleavage and blastocyst formation were evaluated and compared with embryos obtained from non-translocation cases undergoing ICSI (n = 98 cycles). In 28 cycles, preimplantation genetic diagnosis (PGD) was performed on prezygotes (first and second polar body biopsy for female carriers; n = 3) or on embryos having seven or more blastomeres (blastomere biopsy; n = 25). In six cycles for four couples, probes for translocated chromosomes were not available, so PGD could not be performed. Overall, in translocation cases, a lower fertilization rate, a higher rate of retarded embryo development, and a lower rate of blastocyst formation were observed compared with embryos of non-translocation cases. Fluorescence in-situ hybridization (FISH) analysis showed a 70.9% abnormality rate for reciprocal translocations and 55.0% for Robertsonian translocations respectively. In cases with Robertsonian and reciprocal translocation carriers, the probability of poor embryo development, which may be a result of high segregation abnormalities, may negatively affect the outcome of assisted reproductive techniques. This poor prognosis should also be considered when genetic counselling for translocation is given.     

Prenatal search for UPD 14 and UPD 15 in 83 cases of familial and de novo heterologous Robertsonian translocations

OBJECTIVES: The presence in the conceptus of a Robertsonian translocation predisposes to UPD formation, mainly by post-zygotic events of chromosome abnormality rescue. This is due to the increased risk of generating aneuploid zygotes because the rearranged chromosome and the respective homologues are prone to non-disjunction errors. Given this, carriers and karyotypically normal individuals conceived from a parent with a Robertsonian translocation are at risk for UPD. Abnormal phenotypes due to an imprinting effect have been found to be associated with UPD 14 and 15.The aim of the study was to refine, at the time of prenatal diagnosis, the risk for UPD 14 and 15 in a population with Robertsonian translocations involving these chromosomes. METHODS: Sixty-five cases of familial and de novo heterologous Robertsonian translocations involving chromosomes 14 and 15 and 18 fetuses with a normal karyotype, but conceived by a Robertsonian translocation carrier were prenatally studied to investigate the presence of UPD for chromosomes 14 and 15. RESULTS: Of the 65 Robertsonian translocation carriers, one fetus with a de novo der(14;21) showed maternal UPD 14. None of the 18 fetuses with a normal karyotype had UPD. CONCLUSION: Our data, combined with other previous prenatal investigations provide a general risk estimate for UPD 14 and 15 of 0.6%. Nevertheless, combining our data and those previously reported, all three fetuses with UPD had a de novo Robertsonian translocation, thus suggesting a risk of UPD formation of about 3% for this specific group of translocation carriers.     

Preimplantation genetic diagnosis by fluorescence in situ hybridization of reciprocal and Robertsonian translocations

ObjectiveThe presence of reciprocal and Robertsonian chromosomal rearrangement is often related to recurrent miscarriage. Using preimplantation genetic diagnosis, the abortion rate can be decreased. Cases treated at our center were reviewed.Materials and methodsA retrospective analysis for either Robertsonian or reciprocal translocations was performed on all completed cycles of preimplantation genetic diagnosis at our center since the first reported case in 2004 until the end of 2010. Day 3 embryo biopsies were carried out, and the biopsied cell was checked by fluorescent in situ hybridization using relevant informative probes. Embryos with a normal or balanced translocation karyotype were transferred on Day 4.ResultsThirty-eight preimplantation genetic diagnosis cycles involving 17 couples were completed. A total of 450 (82.6%) of the total oocytes were MII oocytes, and 158 (60.0%) of the two-pronuclei embryos were biopsied. In 41.4% of the fluorescent in situ hybridization analyses, the results were either normal or balanced. Embryos were transferred back after 21 cycles. Three babies were born from Robertsonian translocation carriers and another two from reciprocal translocation carriers. The miscarriage rate was 0%. Among the reciprocal translocation group, the live delivery rate was 8.3% per ovum pick-up cycle and 18.2% per embryo transfer cycle. Among the Robertsonian translocation group, the live delivery rate was 14.3% per ovum pick-up cycle and 20.0% per embryo transfer cycle.ConclusionThere is a trend whereby the outcome for Robertsonian translocation group carriers is better than that for reciprocal translocation group carriers. Aneuploidy screening may possibly be added in order to improve the outcome, especially for individuals with an advanced maternal age. The emergence of an array-based technology should help improve this type of analysis.     

The application of PGT-A for carriers of balanced structural chromosomal rearrangements

Abstract

The aim of this study was to analyze differences in chromosomal aberrations and euploidy in embryos of each translocation type and gender of carrier in the case series of 10 couples with balanced translocations who underwent IVF with embryos trophectoderm (TE) biopsy and PGT-A to detect chromosomal aberrations. This is a Case Series (Retrospective study). In each case, controlled ovarian hyperstimulation, oocyte insemination with intracytoplasmic sperm injection (ICSI) and cultivation gave multiple blastocysts, that underwent trophectoderm (TE) biopsy with PGT-A analysis using aCGH and NGS. Number of total unbalanced translocations compared to the number of sporadic aneuploid embryos was 39.6% to 39.6% (50% to 50% of all 37 aneuploid embryos). The highest euploidy rate was in male carrier group – 26.7% and the lowest in the Robertsonian translocation carrier group – 18.2%. Sporadic aneuploidy – 68.2% was highest in Robertsonian translocation carrier group and lowest in female group – 11.1%. Chromosomal aberrations related to translocation were highest in female carrier group – 77.8% and lowest in Robertsonian translocation carrier group – 13.6%. Our study showed that expectancy of total embryo aneuploidy rates will be higher in carriers, than in people with normal karyotype. The prevalence of chromosomal aberrations related to translocation was 4.5 times higher in Reciprocal carrier group than in Robertsonian translocation carrier group. Among maternal and paternal carrier groups, the embryos from female carriers had the lowest euploidy rate, unbalanced translocation rate 4.7 times higher than in the male carrier group and higher total aneuploidy rates.     

Prenatally diagnosed balanced chromosome rearrangements: eight years' experience

OBJECTIVE: To investigate the incidence and pregnancy outcome of prenatally diagnosed balanced chromosome rearrangements from amniocentesis. STUDY DESIGN: Between January 1996 and December 2003, we collected cases with balanced chromosome rearrangements from amniocentesis specimens submitted to our cytogenetics laboratory for fetal karyotyping. Data on maternal age, indication for amniocentesis, detailed anatomic sonographic findings, gestational age at delivery, newborn birth weight and infant anomalies, if any, were obtained by chart review. RESULTS: A total of 66 cases of balanced chromosomal translocations or inversions were identified from the 12,468 amniocentesis specimens. Specifically, 0.256% had a reciprocal translocation, 0.080% had a Robertsonian translocation, and 0.192% had an inversion. The incidences of de novo reciprocal translocations, Robertsonian translocations and inversions were 0.080%, 0.016% and 0.024%, respectively. Abnormal prenatal sonographic findings occurred in 2 cases, 1 in an inherited case and 1 in a de novo case. Abnormal postnatal findings occurred in 5 cases, 3 in inherited cases and 2 in de novo cases. Excluding the cases with minor congenital anomalies, the major congenital anomaly rates of inherited and de novo chromosome rearrangements were 1.96% and 6.66%, respectively. CONCLUSION: The incidences of prenatally diagnosed de novo reciprocal translocations, de novo Robertsonian translocations and de novo inversions were higher than those reported in previous, larger series. The major congenital anomaly rates for inherited and de novo chromosome rearrangements were higher than the 1.4% congenital anomaly rate in our general population. Consequently, detailed ultrasound examination and parental karyotyping should be viewed as essential measures in dealing with prenatally diagnosed balanced chromosome rearrangements.     

女性罗氏易位携带者辅助生育治疗5例临床分析

目的:探讨应用极体分析和分裂球分析法对反复流产的女性罗氏易位携带者进行着床前遗传学诊断(PGD)的临床策略。方法:采用荧光原位杂交(FISH)技术,对5例患者用全染色体涂抹探针检测第一极体和用特异位点探针检测分裂球中相应染色体的荧光信号。5例女性罗氏易位携带者的外周血淋巴细胞染色体核型分别为:45,XX,der (13;14)(q10;q10)3例,45,XX,der(14;21)(q10;q10)、45,XX,der(21;22)(q10;q10)各1例。结果:5例患者中4例获得妊娠并分娩,其中2例经分裂球分析后妊娠,出生3个婴儿:2个正常核型,1个罗氏易位携带者;1例经极体分析诊断后分娩一正常男婴;另1例极体分析未明确诊断又行分裂球分析选择胚胎移植后,出生1个罗氏易位携带者后代。结论:(1)女性罗氏易位携带者PGD应首选极体分析,争取避免携带者出生;(2)极体分析未能得到诊断的胚胎可在分裂球期再次PGD。     

Uniparental disomy in fetuses diagnosed with balanced Robertsonian translocations: risk estimate

Forty-two fetuses with non-homologous Robertsonian translocations were analyzed for uniparental disomy (UPD). One fetus with a de novo translocation t(13q;14q) had maternal isodisomy of chromosome 14. In a summary of the published data (including the present study), 315 cases were analyzed for UPD after prenatal diagnosis of balanced Robertsonian translocations, of these two fetuses had UPD, giving a risk estimate of 0.65% (CI 0.2-2.3). This risk justifies the recommendation of UPD analysis in fetuses diagnosed prenatally with Robertsonian translocations, with the emphasis on the chromosomes known to contain imprinted genes, such as 14 and 15. We also discuss the possibility of UPD in offspring of Robertsonian translocation carriers with normal karyotype. Based on the risk for UPD in fetuses with Robertsonian translocation we suggest to test these fetuses for UPD and to do so on amniocytes rather than chorionic villi when the risk for unbalanced karyotype is approximately 1%, comparable to the risk for UPD.     

Recurrent pregnancy losses and parental chromosome abnormalities: a review

Summary. A compilation of the cytogenetic results taken from 79 published surveys of couples with two or more pregnancy losses (comprising 8208 women and 7834 men) showed an overall prevalence of major chromosome abnormalities of 2.9%. This is five to six times higher than that of the general adult population. In every group of chromosome abnormalities in the parents a predominance of female to male affected was noted (2:1). Approximately 50% of all chromosome abnormalities detected were balanced reciprocal translocations, 24% were Robertsonian translocations, 12% were sex chromosomal mosaicisms in females, and the rest consisted of inversions and other sporadic abnormalities. Parents with two or more idiopathic pregnancy losses should be karyotyped to aid in management and counselling. When a translocation or other abnormality (e.g. X chromosomal mosaicism) predisposing to an abnormal zygote is found, prenatal diagnosis is indicated in future pregnancies. Even when parental karyotypes are normal, prenatal diagnosis should be considered in subsequent pregnancies of parents with two or more pregnancy losses because of the high incidence of chromosome abnormalities in spontaneous abortions. For the same reason, if a single previous pregnancy loss is known to have been chromosomally aneuploid, parental karyotypes may have to be examined (depending upon the finding in the pregnancy loss), and prenatal diagnosis should also be considered in subsequent pregnancies.