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Zhang Z, Luo K, Zhang S, Cheng D, Hu L, Tan YQ, Zhang S, Gong F, Xie P, Lin G. Clinical outcomes in carriers of insertional translocation: a retrospective analysis of comprehensive chromosome screening results. F S Rep 2024; 5:55-62. [PMID: 38524217 PMCID: PMC10958698 DOI: 10.1016/j.xfre.2023.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 03/26/2024] Open
Abstract
Objective To evaluate the clinical outcomes in the carriers of insertional translocation (IT). Design Retrospective case series. Setting University-affiliated reproductive medical center. Patients Twenty-three couples with ITs. Intervention No direct interventions were involved; however, this study included patients who underwent preimplantation genetic testing for structural chromosomal rearrangements (PGT-SR). Main Outcome Measure Outcome of preimplantation genetic testing for structural chromosomal rearrangements and percentage of blastocysts available for transfer. Results Among 23 IT carriers, 15 were simple interchromosome ITs (type A), 3 were intrachromosome IT carriers (type B), and 5 were interchromosome IT carriers combined with other translocations (type C). A total of 190 blastocysts from 30 cycles were biopsied, 187 embryos were tested successfully, and only 57 blastocysts (30.5%) from 21 patients were available for transfer (normal or balanced). The unbalanced rearrangement rate of type C was 79.2% (42/53), and the proportion of type A was 50.0% (57/114), which was significantly higher than that of type B (5%, 1/20). In type A, the probability of embryos harboring unbalanced rearrangement in female carriers was 56.0% (51/91), which was higher than that in male carriers (26.1%, 6/23). Furthermore, the haploid autosomal length value of the inserted fragment was correlated linearly with the incidence of abnormal embryos. In type A gametes, most gametes produced by 2:2 separation without crossover, and no 3:1 separation gamete was observed. Conclusions The chance of identifying normal or balanced and mosaic blastocysts per mature oocytes in patients with ITs are 16.6% (67/404). Greater IT complexity results in fewer transferable embryos. For simple interchromosome ITs, female carriers and those with higher haploid autosomal length values have a higher risk of producing embryos with unbalanced rearrangement.
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Affiliation(s)
- Zhiqi Zhang
- Hospital of Hunan Guangxiu, Hunan Normal University School of Medicine, Hunan, People’s Republic of China
| | - Keli Luo
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Senlin Zhang
- Hospital of Hunan Guangxiu, Hunan Normal University School of Medicine, Hunan, People’s Republic of China
| | - Dehua Cheng
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Liang Hu
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Yue-Qiu Tan
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Shuoping Zhang
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Fei Gong
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
| | - Pingyuan Xie
- Hospital of Hunan Guangxiu, Hunan Normal University School of Medicine, Hunan, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
- National Engineering and Research Center of Human Stem Cells, Changsha, People’s Republic of China
| | - Ge Lin
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, Changsha, People’s Republic of China
- Reproductive and Genetic Hospital of CITIC-Xiangya, Hunan, People’s Republic of China
- Clinical Research Center for Reproduction and Genetics, Hunan Province, People’s Republic of China
- National Engineering and Research Center of Human Stem Cells, Changsha, People’s Republic of China
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Tonyan ZN, Puppo IL, Saifitdinova AF, Vavilova TV, Glotov AS. Assessment of quadrivalent characteristics influencing chromosome segregation by analyzing human preimplantation embryos from reciprocal translocation carriers. COMPARATIVE CYTOGENETICS 2024; 18:1-13. [PMID: 38298496 PMCID: PMC10825968 DOI: 10.3897/compcytogen.18.115070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/21/2023] [Indexed: 02/02/2024]
Abstract
Patterns of meiotic chromosome segregation were analyzed in cleavage stage and blastocyst stage human embryos from couples with autosomal reciprocal translocations (ART). The influence of quadrivalent asymmetry degree, the presence of terminal breakpoints, and the involvement of acrocentric chromosomes in the rearrangement were analyzed to evaluate their contribution to the formation of non-viable embryos with significant chromosomal imbalance due to pathological segregation patterns and to assess the selection of human embryos by the blastocyst stage. A selection of viable embryos resulting from alternate and adjacent-1 segregation and a significant reduction in the detection frequency of the 3 : 1 segregation pattern were observed in human embryos at the blastocyst stage. The presence of terminal breakpoints increased the frequency of 3 : 1 segregation and was also associated with better survival of human embryos resulting from adjacent-1 mode, reflecting the process of natural selection of viable embryos to the blastocyst stage. The demonstrated patterns of chromosome segregation and inheritance of a balanced karyotype in humans will contribute to optimizing the prediction of the outcomes of in vitro fertilization programs and assessing the risks of the formation of unbalanced embryos for ART carriers.
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Affiliation(s)
- Ziravard N. Tonyan
- D. O. Ott Research Institute of Obstetrics, Gynaecology and Reproductology, 3 Mendeleevskaya Line, 199034, Saint Petersburg, RussiaAlmazov National Medical Research CentreSaint PetersburgRussia
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
| | - Irina L. Puppo
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
- International Centre for Reproductive Medicine, 53/1 Komendantskij prospect, 197350, Saint Petersburg, RussiaInternational Centre for Reproductive MedicineSaint PetersburgRussia
| | - Alsu F. Saifitdinova
- International Centre for Reproductive Medicine, 53/1 Komendantskij prospect, 197350, Saint Petersburg, RussiaInternational Centre for Reproductive MedicineSaint PetersburgRussia
- Department of Human and Animal Anatomy and Physiology, Herzen State Pedagogical University of Russia, 48 Moyka River Embankment, 191186, Saint Petersburg, RussiaHerzen State Pedagogical University of RussiaSaint PetersburgRussia
| | - Tatyana V. Vavilova
- Almazov National Medical Research Centre, 2 Akkuratova Street, 197341, Saint Petersburg, RussiaD. O. Ott Research Institute of Obstetrics, Gynaecology and ReproductologySaint PetersburgRussia
| | - Andrey S. Glotov
- D. O. Ott Research Institute of Obstetrics, Gynaecology and Reproductology, 3 Mendeleevskaya Line, 199034, Saint Petersburg, RussiaAlmazov National Medical Research CentreSaint PetersburgRussia
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Yu W, Jin C, Zhang Q, Ni T, Yan J. Does reciprocal translocation affect the meiotic segregation products of non-translocation chromosomes? HUM FERTIL 2023; 26:702-711. [PMID: 37961879 DOI: 10.1080/14647273.2023.2262810] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/25/2023] [Indexed: 11/15/2023]
Abstract
This retrospective cohort study aimed to assess the effect of chromosomal reciprocal translocation on meiotic segregation products of non-translocation chromosomes. A total of 744 reciprocal translocation carriers and 875 non-carriers were included in this study. A total of 6,832 blastocysts were biopsied and tested by next-generation sequencing. Blastocysts from the carrier group were classified into five subgroups according to the theoretical segregation pattern of quadrivalent structure. For carrier patients, normal meiotic segregation products of the non-translocation chromosome were classified after excluding the segregation modes of the quadrivalent structure. The proportion of normal non-translocation chromosome meiotic segregation products was similar between the carrier and noncarrier groups (p = 0.69). The generalized Estimation Equation revealed that there was no correlation between reciprocal translocation and meiotic segregation products of non-translocation chromosomes. Moreover, subgroup analyses showed that the segregation modes of quadrivalent structure (p = 0.00) and carrier's gender (p = 0.00) may affect the meiotic segregation products of non-translocation chromosomes. In conclusion, reciprocal translocation does not directly reduce the proportion of normal segregation products of non-translocation chromosomes. The difference among subgroups of different quadrivalent segregation patterns implied that interchromosomal effect may exist but the high incidence of chromosomal abnormalities for reciprocal translocation carriers should not be attributed to interchromosomal effect.
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Affiliation(s)
- Wenhao Yu
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong, China
- Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Reproductive Medicine, Jinan, Shandong, China
- Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
| | - Chenxi Jin
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong, China
- Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Reproductive Medicine, Jinan, Shandong, China
- Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
| | - Qian Zhang
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong, China
| | - Tianxiang Ni
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong, China
- Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Reproductive Medicine, Jinan, Shandong, China
- Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
| | - Junhao Yan
- Center for Reproductive Medicine, Shandong University, Jinan, Shandong, China
- Key Laboratory of Reproductive Endocrinology of Ministry of Education, Shandong University, Jinan, Shandong, China
- Shandong Key Laboratory of Reproductive Medicine, Jinan, Shandong, China
- Shandong Provincial Clinical Research Center for Reproductive Health, Jinan, Shandong, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Shandong University, Jinan, Shandong, China
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Wallis MJ, Kelly AL, Peters GB, St Heaps L, Nandini A, McGaughran JM. A balanced paternal interchromosomal reciprocal insertion between 5q12.1q13.2 and 20p12.3p12.1 resulting in separate genetic conditions in two siblings. Am J Med Genet A 2016; 170:1930-3. [DOI: 10.1002/ajmg.a.37689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2015] [Accepted: 04/14/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Mathew J. Wallis
- Genetic Health Queensland; Royal Brisbane and Women's Hospital; Brisbane Queensland
- School of Medicine; The University of Queensland; Brisbane Queensland
| | - Amanda L. Kelly
- Genetic Health Queensland; Royal Brisbane and Women's Hospital; Brisbane Queensland
| | - Gregory B. Peters
- Department of Cytogenetics; The Children's Hospital at Westmead; Sydney New South Wales
| | - Luke St Heaps
- Department of Cytogenetics; The Children's Hospital at Westmead; Sydney New South Wales
| | - Adayapalam Nandini
- Department of Cytogenetics; Royal Brisbane and Women's Hospital; Brisbane Queensland
| | - Julie M. McGaughran
- Genetic Health Queensland; Royal Brisbane and Women's Hospital; Brisbane Queensland
- School of Medicine; The University of Queensland; Brisbane Queensland
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5
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Peters GB, Pertile MD. Chromosome microarrays in diagnostic testing: interpreting the genomic data. Methods Mol Biol 2014; 1168:117-155. [PMID: 24870134 DOI: 10.1007/978-1-4939-0847-9_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
DNA-based Chromosome MicroArrays (CMAs) are now well established as diagnostic tools in clinical genetics laboratories. Over the last decade, the primary application of CMAs has been the genome-wide detection of a particular class of mutation known as copy number variants (CNVs). Since 2010, CMA testing has been recommended as a first-tier test for detection of CNVs associated with intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies…in the post-natal setting. CNVs are now regarded as pathogenic in 14-18 % of patients referred for these (and related) disorders.Through consideration of clinical examples, and several microarray platforms, we attempt to provide an appreciation of microarray diagnostics, from the initial inspection of the microarray data, to the composing of the patient report. In CMA data interpretation, a major challenge comes from the high frequency of clinically irrelevant CNVs observed within "patient" and "normal" populations. As might be predicted, the more common and clinically insignificant CNVs tend to be the smaller ones <100 kb in length, involving few or no known genes. However, this relationship is not at all straightforward: CNV length and gene content are only very imperfect indicators of CNV pathogenicity. Presently, there are no reliable means of separating, a priori, the benign from the pathological CNV classes.This chapter also considers sources of technical "noise" within CMA data sets. Some level of noise is inevitable in diagnostic genomics, given the very large number of data points generated in any one test. Noise further limits CMA resolution, and some miscalling of CNVs is unavoidable. In this, there is no ideal solution, but various strategies for handling noise are available. Even without solutions, consideration of these diagnostic problems per se is informative, as they afford critical insights into the biological and technical underpinnings of CNV discovery. These are indispensable to any clinician or scientist practising within the field of genome diagnostics.
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Affiliation(s)
- Greg B Peters
- Sydney Genome Diagnostics, The Childrens Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW, 2145, Australia,
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Kayhan G, Ergün MA, Biri AA, Karaoğuz MY. A prenatal tertiary trisomy resulting from balanced maternal 8; 9 translocation. J Turk Ger Gynecol Assoc 2011; 12:183-5. [PMID: 24591989 DOI: 10.5152/jtgga.2011.42] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 09/09/2010] [Indexed: 11/22/2022] Open
Abstract
An additional derivative chromosome 8 was found in the cytogenetic analyses of the chorionic villus biopsy specimen of a balanced reciprocal translocation carrier mother. This was a 3:1 segregation of the unbalanced product of the balanced maternal 8:9 translocation. The chromosomes of the carrier of the balanced reciprocal translocation pair with their matching homologous segments at meiosis I, a quadrivalent figure is formed and chromosomes segregate from this configuration. Increased nuchal tranaslucency was also determined on fetal sonography at the 13(rd) week of gestation. The final karyotype was 47,X Y,+der(8)t(8;9)(q11.2;p22) mat, and the parents were informed about this tertiary trisomy. After genetic counseling, the parents decided to terminate the pregnancy. The presented case is a reminder of the probability of the unbalanced products of the 3:1 segregation, rather than the common 2:2 segregation.
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Affiliation(s)
- Gülsüm Kayhan
- Department of Medical Genetics, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Mehmet Ali Ergün
- Department of Medical Genetics, Faculty of Medicine, Gazi University, Ankara, Turkey
| | - Aydan Asyalı Biri
- Department of Obstetrics and Gynecology, Faculty of Medicine, Gazi University, Ankara, Turkey
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7
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Albano F, Anelli L, Zagaria A, Coccaro N, Casieri P, Rossi AR, Vicari L, Liso V, Rocchi M, Specchia G. Non random distribution of genomic features in breakpoint regions involved in chronic myeloid leukemia cases with variant t(9;22) or additional chromosomal rearrangements. Mol Cancer 2010; 9:120. [PMID: 20500819 PMCID: PMC2887383 DOI: 10.1186/1476-4598-9-120] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2010] [Accepted: 05/25/2010] [Indexed: 12/12/2022] Open
Abstract
Background The t(9;22)(q34;q11), generating the Philadelphia (Ph) chromosome, is found in more than 90% of patients with chronic myeloid leukemia (CML). As a result of the translocation, the 3' portion of the ABL1 oncogene is transposed from 9q34 to the 5' portion of the BCR gene on chromosome 22 to form the BCR/ABL1 fusion gene. At diagnosis, in 5-10% of CML patients the Ph chromosome is derived from variant translocations other than the standard t(9;22). Results We report a molecular cytogenetic study of 452 consecutive CML patients at diagnosis, that revealed 50 cases identifying three main subgroups: i) cases with variant chromosomal rearrangements other than the classic t(9;22)(q34;q11) (9.5%); ii) cases with cryptic insertions of ABL1 into BCR, or vice versa (1.3%); iii) cases bearing additional chromosomal rearrangements concomitant to the t(9;22) (1.1%). For each cytogenetic group, the mechanism at the basis of the rearrangement is discussed. All breakpoints on other chromosomes involved in variant t(9;22) and in additional rearrangements have been characterized for the first time by Fluorescence In Situ Hybridization (FISH) experiments and bioinformatic analyses. This study revealed a high content of Alu repeats, genes density, GC frequency, and miRNAs in the great majority of the analyzed breakpoints. Conclusions Taken together with literature data about CML with variant t(9;22), our findings identified several new cytogenetic breakpoints as hotspots for recombination, demonstrating that the involvement of chromosomes other than 9 and 22 is not a random event but could depend on specific genomic features. The presence of several genes and/or miRNAs at the identified breakpoints suggests their potential involvement in the CML pathogenesis.
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King WA, Gustavsson I, Popescu CP, Linares T. Gametic products transmitted by rcp(13q--;14q+) translocation heterozygous pigs, and resulting embryonic loss. Hereditas 2009; 95:239-46. [PMID: 7309540 DOI: 10.1111/j.1601-5223.1981.tb01413.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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Gustavsson I, Settergren I, King WA. Occurrence of two different reciprocal translocations in the same litter of domestic pigs. Hereditas 2008; 99:257-67. [PMID: 6668212 DOI: 10.1111/j.1601-5223.1983.tb00898.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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Gustavsson I, Jönsson L. Stillborns, partially monosomic and partially trisomic, in the offspring of a boar carrying a translocation: rcp(14;15)(q29;q24). Hereditas 2008; 117:31-7. [PMID: 1399704 DOI: 10.1111/j.1601-5223.1992.tb00004.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Smaller liters and an increased rate of stillbirth were observed among the offspring of a boar carrying a reciprocal translocation, rcp(14;15)(q29;q24). The translocation appeared to be of de novo origin since, according to the owner, the sire and dam of the proband boar both produced normal-sized litters and no stillbirths. The increased rate of stillbirth among offspring of the proband was due to the production of zygotes partially monosomic for chromosome 14 (14q29-qter) and partially trisomic for chromosome 15 (15q24----qter). Three out of 4 such stillborn piglets had a cleft palate. One of the 4 also had a cardiac septal defect. Two partially monosomic and partially trisomic foetuses recovered at 95 days' pregnancy appeared patho-anatomically normal. The smaller litters were assumed to be due to an early wastage of embryos having other types of unbalanced karyotypes caused by the reciprocal translocation.
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Affiliation(s)
- I Gustavsson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala
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12
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Takagishi J, Rauen KA, Drumheller T, Kousseff B, Sutcliffe M. Chromosome 3p25 deletion in mother and daughter with minimal phenotypic effect. Am J Med Genet A 2006; 140:1587-93. [PMID: 16770804 DOI: 10.1002/ajmg.a.31325] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
3p25 deletion syndrome is characterized by mental retardation, growth retardation, hypotonia, microcephaly, ptosis, and micrognathia. Of the 42 persons with this deletion syndrome cited in the literature, only 2 patients, a mother-daughter pair, have previously been reported without apparent clinical consequence. We present a second mother-daughter dyad with a terminal 3p25.3-3pter deletion, who present with only mild clinical effects. In addition to cytogenetic analysis, array CGH was performed to determine the breakpoints at the molecular level. Our data show that the 3p25 deletion syndrome may, therefore, reflect a much broader phenotypic spectrum than previously recognized.
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Affiliation(s)
- Jennifer Takagishi
- Department of Pediatrics, Division of General Pediatrics, University of South Florida, Tampa, USA.
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Abstract
In total, 200 families were reviewed with directly transmitted, cytogenetically visible unbalanced chromosome abnormalities (UBCAs) or euchromatic variants (EVs). Both the 130 UBCA and 70 EV families were divided into three groups depending on the presence or absence of an abnormal phenotype in parents and offspring. No detectable phenotypic effect was evident in 23/130 (18%) UBCA families ascertained mostly through prenatal diagnosis (group 1). In 30/130 (23%) families, the affected proband had the same UBCA as other phenotypically normal family members (group 2). In the remaining 77/130 (59%) families, UBCAs had consistently mild consequences (group 3). In the 70 families with established EVs of 8p23.1, 9p12, 9q12, 15q11.2, and 16p11.2, no phenotypic effect was apparent in 38/70 (54%). The same EV was found in affected probands and phenotypically normal family members in 30/70 families (43%) (group 2), and an EV co-segregated with mild phenotypic anomalies in only 2/70 (3%) families (group 3). Recent evidence indicates that EVs involve copy number variation of common paralogous gene and pseudogene sequences that are polymorphic in the normal population and only become visible at the cytogenetic level when copy number is high. The average size of the deletions and duplications in all three groups of UBCAs was close to 10 Mb, and these UBCAs and EVs form the "Chromosome Anomaly Collection" at http://www.ngrl.org.uk/Wessex/collection. The continuum of severity associated with UBCAs and the variability of the genome at the sub-cytogenetic level make further close collaboration between medical and laboratory staff essential to distinguish clinically silent variation from pathogenic rearrangement.
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Affiliation(s)
- J C K Barber
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Salisbury, Wiltshire SP2 8BJ, UK.
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Buwe A, Guttenbach M, Schmid M. Effect of paternal age on the frequency of cytogenetic abnormalities in human spermatozoa. Cytogenet Genome Res 2006; 111:213-28. [PMID: 16192697 DOI: 10.1159/000086892] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Accepted: 05/17/2005] [Indexed: 11/19/2022] Open
Abstract
Many surveys have been performed to find etiological relationships between pregnancy outcome and specific risk factors, such as exposure to chemicals and radiation or parental age. Advanced maternal age is a strong risk factor for trisomic pregnancies, albeit there are considerable variations among the different chromosomes. The definite incidence of the various structural and numerical chromosome aberrations in spontaneous abortions and liveborns is well known, as well as the rate of maternally and paternally derived rearrangements. Nevertheless studies have failed to assert an age-dependent risk for men fathering chromosomally abnormal children. New techniques using fluorescence in situ hybridization render it possible to analyze spermatozoa directly for numerical and, to some extent, for structural aberrations. This article compiles the findings of studies on human spermatozoa over the last few years.
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Affiliation(s)
- A Buwe
- Department of Human Genetics, Biozentrum, University of Würzburg, Würzburg, Germany
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Fisher AM, Strike P, Scott C, Moorman AV. Breakpoints of variant 9;22 translocations in chronic myeloid leukemia locate preferentially in the CG-richest regions of the genome. Genes Chromosomes Cancer 2005; 43:383-9. [PMID: 15884100 DOI: 10.1002/gcc.20196] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
From 5% to 10% of 9;22 translocations in chronic myeloid leukemia (CML) are reported to occur in variant form, that is, with the involvement of other regions of the genome in 3-way or more rearrangements. The literature indicates that the alternative breakpoints are not distributed randomly in the genome but show hotspots. We present data on 289 unpublished cases of CML with variant 9;22 translocations having a total of 342 variant breakpoints, the largest independent series to date. We found that the distribution of breaks was in loose agreement with the literature but that some new hotspots were identified; furthermore, some published hotspots were not fully supported by our data. Moreover, when our 342 variant breakpoints were plotted against profiles of CG heterogeneity in the genome, a significant positive correlation between breakpoint locations and CG composition was observed. In an ancillary study, we compared the frequency of variant t(9;22) with that of variants of t(15;17) associated with acute promyelocytic leukemia (AML M3). We found that the frequency of the former, 9.3%, was significantly higher than that of the latter, 2.6%.
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MESH Headings
- Base Composition
- Chromosome Breakage
- Chromosomes, Human, Pair 22
- Chromosomes, Human, Pair 9
- Databases, Factual
- Genome, Human
- Humans
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics
- Leukemia, Myeloid, Acute/genetics
- Translocation, Genetic
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Affiliation(s)
- Andrew M Fisher
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, UK.
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Takeno SS, Corbani M, Andrade JAD, Smith MDAC, Brunoni D, Melaragno MI. Duplication 4p and deletion 4p (Wolf-Hirschhorn syndrome) due to complementary gametes from a 3:1 segregation of a maternal balanced t(4;13)(p16;q11) translocation. ACTA ACUST UNITED AC 2004; 129A:180-3. [PMID: 15316961 DOI: 10.1002/ajmg.a.30224] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We present clinical and cytogenetic data on a family with a t(4;13)(p16;q11) translocation present in four generations. The balanced translocation resulted in one individual with monosomy 4p and one individual with trisomy 4p, due to 3:1 segregation. The male patient with trisomy 4p was fertile and transmitted the extra chromosome to his daughter.
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Affiliation(s)
- S S Takeno
- Genetics Division, Universidade Federal de São Paulo, São Paulo, SP, Brazil
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17
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Li S, Malafiej P, Levy B, Mahmood R, Field M, Hughes T, Lockhart LH, Wu Z, Huang M, Hirschhorn K, Velagaleti GVN, Daniel A, Warburton PE. Chromosome 13q neocentromeres: molecular cytogenetic characterization of three additional cases and clinical spectrum. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 110:258-67. [PMID: 12116235 DOI: 10.1002/ajmg.10454] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
We report three new cases of chromosome 13 derived marker chromosomes, found in unrelated patients with dysmorphisms and/or developmental delay. Molecular cytogenetic analysis was performed using fluorescence in situ hybridization (FISH) with chromosome-specific painting probes, alpha satellite probes, and physically mapped probes from chromosome 13q, as well as comparative genomic hybridization (CGH). This analysis demonstrated that these markers consisted of inversion duplications of distal portions of chromosome 13q that have separated from the endogenous chromosome 13 centromere and contain no detectable alpha satellite DNA. The presence of a functional neocentromere on these marker chromosomes was confirmed by immunofluorescence with antibodies to centromere protein-C (CENP-C). The cytogenetic location of a neocentromere in band 13q32 was confirmed by simultaneous FISH with physically mapped YACs from 13q32 and immunofluorescence with anti-CENP-C. The addition of these three new cases brings the total number of described inv dup 13q neocentic chromosomes to 11, representing 21% (11/52) of the current overall total of 52 described cases of human neocentric chromosomes. This higher than expected frequency suggests that chromosome 13q may have an increased propensity for neocentromere formation. The clinical spectrum of all 11 cases is presented, representing a unique collection of polysomy for different portions of chromosome 13q without aneuploidies for additional chromosomal regions. The complexity and variability of the phenotypes seen in these patients does not support a simple reductionist view of phenotype/genotype correlation with polysomy for certain chromosomal regions.
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Affiliation(s)
- Shulan Li
- Department of Human Genetics Mount Sinai School of Medicine, New York, New York 10029, USA
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18
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Roggenbuck JA, Fink JM, Mendelsohn NJ. Unique case of trisomy 2p24.3-pter with no associated monosomy. ACTA ACUST UNITED AC 2001. [DOI: 10.1002/ajmg.1309] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Zimmermann-Bär U, Stallmach T, Riegel M, Wiedemann U, Fauchère JC, Binkert F, Kotzot D. Wolf-Hirschhorn syndrome due to a 3:1 segregation of a maternal balanced t(4;15)(p16.3;q11) translocation. Prenat Diagn 2000; 20:847-50. [PMID: 11038468 DOI: 10.1002/1097-0223(200010)20:10<847::aid-pd930>3.0.co;2-o] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Wolf-Hirschhorn syndrome (WHS) is characterized by severe pre- and postnatal growth retardation, specific pattern of dysmorphisms, and severe developmental delay. These clinical findings are the result of a deletion within the short arm of chromosome 4. Most cases occur de novo and are of paternal origin. Cases due to a balanced translocation are mostly of maternal origin and the deletion of distal 4p, including the WHS critical region, is often combined with a duplication of the other chromosomal segment involved in the rearrangement. Here, we report on a newborn female infant with WHS and pure tertiary monosomy due to a 3:1 segregation of a balanced maternal 4;15 translocation. In this context, importance of fluorescence in situ hybridization (FISH) with specific probes to determine the exact breakpoints in unbalanced chromosomal rearrangements with breakpoints localized around known microdeletion syndromes is emphasized.
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20
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Rodríguez de Alba M, Sanz R, Lorda-Sanchez I, Fernández-Moya JM, Ayuso C, Díaz-Recasens J, Ramos C. Segregation of digital number with partial monosomy or trisomy of 13q in familial 5;13 translocation. Prenat Diagn 1999; 19:884-6. [PMID: 10521852 DOI: 10.1002/(sici)1097-0223(199909)19:9<884::aid-pd655>3.0.co;2-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
It has been postulated that the deletion of band 13q22 may be associated with digital malformations, especially thumb and big toe anomalies. We report a family where the mother is carrying a balanced translocation between chromosomes 5p15 and 13q22. The offspring have a specific and well-defined phenotype depending on which is the unbalanced chromosome in the karyotype. When a partial trisomy of 13q22-->qter is present, the fetuses have polydactyly in the four limbs, and when the fetus is carrying a partial monosomy of this portion, an oligodactyly in all members can be observed.
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21
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Barber JC, Joyce CA, Collinson MN, Nicholson JC, Willatt LR, Dyson HM, Bateman MS, Green AJ, Yates JR, Dennis NR. Duplication of 8p23.1: a cytogenetic anomaly with no established clinical significance. J Med Genet 1998; 35:491-6. [PMID: 9643291 PMCID: PMC1051344 DOI: 10.1136/jmg.35.6.491] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
We present seven families with a cytogenetic duplication of the short arm of chromosome 8 at band 8p23.1. The duplication has been transmitted from parents to offspring in four of the seven families. In three families, the source of the extra material and its euchromatic origin were established using FISH with a YAC which was mapped to 8p23.1 and a whole chromosome paint for chromosome 8. FISH signals from this YAC were significantly larger on the duplicated chromosome compared with the normal chromosome in all six family members tested. Comparative genomic hybridisation (CGH) on a representative subject was consistent with these results. The families were ascertained for a variety of mostly incidental reasons including prenatal diagnosis for advanced maternal age. The transmission of this duplication by multiple phenotypically normal family members with no history of reproductive loss suggests the existence of a novel class of 8p23.1 duplications, which can be regarded as euchromatic variants or duplications with no phenotypic effect.
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Affiliation(s)
- J C Barber
- Wessex Regional Genetics Laboratory, Salisbury District Hospital, Wiltshire, UK
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22
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Abstract
Constitutional chromosomal abnormalities are an important cause of miscarriage, infertility, congenital anomalies and mental retardation in humans. Most human constitutional chromosomal imbalance results from aneuploidy, a condition that appears to be much more frequent in humans than in any other species studied. Chromosomal rearrangements and segmental deletions and duplications also occur in humans, but much less often. Although treatment of human somatic cells with some environmental agents produces chromosomal damage, no measurable increase in the frequency of constitutional chromosomal abnormalities has been unequivocally demonstrated among the children of parents exposed to any agent. Recent work has provided insight into a variety of mechanisms by which chromosomal abnormalities can arise during gametogenesis and early embryogenesis. Mechanisms have also been recognized that can correct or partially compensate for chromosomal imbalance, sometimes permitting survival of conceptuses that would otherwise be lost early in gestation. This improved understanding can be used to refine future studies of the cytogenetic effects of environmental exposures.
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Affiliation(s)
- D E McFadden
- Department of Pathology, B.C. Children's Hospital, Canada.
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23
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Rogers JC, Harris DJ, Pasztor LM. Reciprocal translocation 4;11 with both adjacent-1 segregants viable within a family. Clin Genet 1997; 51:250-6. [PMID: 9184247 DOI: 10.1111/j.1399-0004.1997.tb02464.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We describe a family carrying a balanced 4;11 translocation in which both adjacent-1 segregants are viable. The proband had an unbalanced karyotype: 46,XY,der(11)t(4;11)(q34.3;q23.1)mat. At 8.5 years of age he showed trigonocephaly, hypertelorism, epicanthal folds, down-slanting palpebral fissures, low-set ears, anteverted nares, down-turned carp-shaped mouth, and bilateral fifth finger clinodactyly. His maternal aunt was also dysmorphic with high-arched palate, short philtrum and mild developmental delay. Her karyotype was 46,XX,der(4)t(4;11)(q34.3;q23.1)pat. Other relatives who likely carried a chromosomally unbalanced segregant were identified from photographs and medical records. We compare the clinical findings in our family with descriptions of other similar karyotypic abnormalities from previous case reports.
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Affiliation(s)
- J C Rogers
- Section of Genetics, The Children's Mercy Hospital, University of Missouri School of Medicine, Kansas City 64108, USA
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Barisić I, Zergollern L, Muzinić D, Hitrec V. Risk estimates for balanced reciprocal translocation carriers--prenatal diagnosis experience. Clin Genet 1996; 49:145-51. [PMID: 8737980 DOI: 10.1111/j.1399-0004.1996.tb03274.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
An analysis was performed on 40 families at risk for an unbalanced rearrangement in the fetus because one of the parents is a reciprocal translocation carrier. The overall risk at second trimester prenatal diagnosis was 14% (8/57). The individual risk for unbalanced offspring at second trimester prenatal diagnoses and at birth were estimated using empirical data by Stengel-Rutkowski et al. (1988). The risks at birth ranged from 0%-21.6%. Most reciprocal translocations (22 or 55%) were at low risk. Without risk (7 or 17.5%), medium risk (6 or 15%) and high risk (5 or 12.5%) translocations were about equally represented and relatively infrequent. The analysis shows that the mode of ascertainment as well as the measurement of lengths of observed or probable imbalances cannot serve as a reliable risk predictor in individual counselling. In the translocations ascertained through spontaneous abortions the risk is frequently small or nonexistent, but remarkable exceptions to this rule are observed. Translocations discovered through unbalanced offspring were found to belong to different risk groups with the exception of the no risk group. Individual risk estimates have to be performed as a basis of genetic counselling before or during pregnancy so that parents with reciprocal translocations can make their choices regarding the available options.
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Affiliation(s)
- I Barisić
- Department of Pediatrics, Children's Hospital Zagreb, Croatia
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25
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Batista DA, Pai GS, Stetten G. Molecular analysis of a complex chromosomal rearrangement and a review of familial cases. AMERICAN JOURNAL OF MEDICAL GENETICS 1994; 53:255-63. [PMID: 7856662 DOI: 10.1002/ajmg.1320530311] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A complex chromosome rearrangement (CCR) involving chromosomes 7, 8, and 13 was detected in a phenotypically normal woman ascertained through her mentally retarded son with abnormal phenotype. He had a karyotype with 47 chromosomes including an extra der(13). In initial banding studies the CCR in the mother was interpreted as a three-way translocation. Fluorescence in situ hybridization with whole chromosome libraries and a telomere-specific probe was used to better characterize the rearrangement. Combined data allowed us to reinterpret the CCR as a translocation and an insertion. A review of 35 familial CCRs involving at least three chromosomes led to the following observations: 1) familial CCRs tend to have fewer chromosomes involved and fewer break-points than do de novo CCRs; 2) familial transmission is mainly observed through female carriers although the origin of de novo cases is paternal; 3) an apparent excess of balanced female carriers among the offspring of index carriers was noted; and 4) meiotic segregation resulting in malformed liveborn infants is most frequently due to adjacent-1 segregation, followed by 4:2 segregation; no adjacent-2 segregation was observed.
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Affiliation(s)
- D A Batista
- Department of Gynecology and Obstetrics, Johns Hopkins University, Baltimore, Maryland
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26
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Lurie IW, Wulfsberg EA, Prabhakar G, Rosenblum-Vos LS, Supovitz KR, Cohen MM. Complex chromosomal rearrangements: some breakpoints may have cellular adaptive significance. Clin Genet 1994; 46:244-7. [PMID: 7529663 DOI: 10.1111/j.1399-0004.1994.tb04234.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cytogenetic study of a 3-year-old girl with developmental delay and some minor abnormalities revealed a complex chromosome rearrangement (CCR) involving seven chromosomes with eight breakpoints, leading to monosomy of segment 5q15-q22. According to breakpoint distribution, CCRs may be classified as those with primary intrachromosomal abnormalities (including inversions, insertions, duplications, etc.) and those without them. Only the latter group of CCRs was used in this analysis. Comparison of theoretical and observed breakpoint distributions in 33 cases demonstrated that recurrent involvement of some chromosome(s) ("re-entry") occurs more frequently than expected. One possible explanation for this observation suggests that the initial event leads to an unstable provisional rearrangement, and subsequent breaks are necessary to stabilize the karyotype.
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Affiliation(s)
- I W Lurie
- Department of Pediatrics and Obstetrics, School of Medicine, University of Maryland at Baltimore
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27
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Elbistan M, Aydin M, Bagci H, Kara N. A case of hypogonadism with a translocation: t(4; 12) (q25; q24.2). Indian J Pediatr 1994; 61:421-6. [PMID: 8002074 DOI: 10.1007/bf02751907] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- M Elbistan
- Department of Medical Biology, Faculty of Medicine, Ondokuz Mayis University, Samsun, Turkey
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28
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Cans C, Cohen O, Lavergne C, Mermet MA, Demongeot J, Jalbert P. Logistic regression model to estimate the risk of unbalanced offspring in reciprocal translocations. Hum Genet 1993; 92:598-604. [PMID: 8262520 DOI: 10.1007/bf00420946] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The aim of this study was to estimate the risk of viable unbalanced offspring for a parental carrier of reciprocal translocation. On a large computerized database of reciprocal translocations we used logistic regression to model this risk. The status of the progeny is the outcome variable. Explanatory covariates are cytogenetic characteristics of the translocation, age and sex of the parental carrier, and potential viability of the gametes. The results obtained by the logistic model demonstrate the important role of certain variables such as the sex of the parental carrier and the R band length of the translocated segments. Within the group of lower risk (risk of viable unbalanced offspring less than 5%), 97% of the individuals are correctly classified with this model. For this group, the choice prenatal diagnosis can be best discussed by considering both the risk for viable unbalanced offspring and the risk of induced abortion following prenatal diagnosis.
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Affiliation(s)
- C Cans
- Genetics Laboratory, Medical School, Joseph Fourier University Grenoble, La Tronche, France
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29
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Cotton C, Cummins M, Smith A. Alternate, adjacent 2 and 3:1 meiotic segregation products from a balanced t(13;18) (q12;q11) carrier. Clin Genet 1993; 44:193-5. [PMID: 8261649 DOI: 10.1111/j.1399-0004.1993.tb03878.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We present a case in which alternate, adjacent 2 and 3:1 meiotic segregations have occurred in the pregnancies of a female carrier of a balanced reciprocal translocation -46,XX,t(13;18) (q12;q11). Products of five conceptions effectively showed trisomy 18q, trisomy 18p or monosomy 18p. This is one of the rare rearrangements which can give rise to a variety of segregation modes including adjacent 2.
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Affiliation(s)
- C Cotton
- Department of Genetics, Children's Hospital, Camperdown, NSW, Australia
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30
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Midro AT, Stengel-Rutkowski S, Stene J. Experiences with risk estimates for carriers of chromosomal reciprocal translocations. Clin Genet 1992; 41:113-22. [PMID: 1563084 DOI: 10.1111/j.1399-0004.1992.tb03646.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The risk estimates for individual carriers of ten different familial reciprocal translocations detected among 500 couples with reproductive failures are presented. These were established by application of the empirical data analysed by Stengel-Rutkowski et al. (1988) and the guidelines given in Stene & Stengel-Rutkowski (1988). Different risks were estimated for unbalanced offspring at birth or at second trimester prenatal diagnosis for abortions, or stillbirths/early deaths. These risk estimates varied considerably from translocation to translocation. Carriers of five translocations had risks for offspring with single-segment imbalances. The birth risk figures ranged from 0.1% to 13.8%. Carriers of five other translocations had risks for double-segment imbalances with birth risks ranging from 0% to 3.2%. The estimated risk figures were independent of the method of ascertainment. Among the parents of the index cases we found nine maternal carriers and only one paternal carrier. This presentation illustrates the need for individual risk counselling of each carrier with reciprocal translocation regarding further family planning.
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Affiliation(s)
- A T Midro
- Department of Clinical Genetics, Institute of Obstetrics and Gynecology, Medical Academy, Bialystok, Poland
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31
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Phillips OP, Tharapel AT, Shulman LP, Simpson JL, Elias S. Segregation analysis and genetic counseling when both parents carry balanced chromosomal translocations. Fertil Steril 1991; 56:646-52. [PMID: 1915938 DOI: 10.1016/s0015-0282(16)54594-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE To assess the risk of chromosomally abnormal offspring and discuss counseling approach when both parents carry balanced translocations. DESIGN Theoretical segregation analysis is performed and use of empiric data is used in genetic counseling. SETTING Patients are referred to Division of Reproductive Genetics at the University of Tennessee, Memphis. PATIENTS, PARTICIPANTS The mother, heterozygous for reciprocal translocation 46,XX, rcp(7;13)(p21;q22) and father, heterozygous for Robertsonian translocation 45,XY,rob(13q;14q) were referred for genetic counseling concerning risks of chromosomally abnormal offspring. INTERVENTIONS Segregation analysis, genetic counseling, and chorionic villus sampling. MAIN OUTCOME MEASURE(S) A cumulative risk was derived to use for counseling purposes. Cytogenetics using GTG-banding was performed on cultured chorionic villus cells. RESULTS Theoretical risk of this couple having chromosomally abnormal offspring was 40.5%. On the basis of empirical data and risk factors inherent in the specific translocations, the maternal contribution at midtrimester was 3.5%; the paternal contribution was 1% to 2%. The sum of these risks was used in counseling. CONCLUSIONS The fetus was found to be 46,XY,rcp(7;13)(p21;q22).
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MESH Headings
- Abortion, Habitual/genetics
- Adult
- Chromosomes, Human, Pair 13
- Chromosomes, Human, Pair 14
- Chromosomes, Human, Pair 21
- Chromosomes, Human, Pair 7
- Female
- Genetic Counseling
- Humans
- Male
- Pregnancy
- Translocation, Genetic
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32
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Barber JC, Mahl H, Portch J, Crawfurd MD. Interstitial deletions without phenotypic effect: prenatal diagnosis of a new family and brief review. Prenat Diagn 1991; 11:411-6. [PMID: 1924182 DOI: 10.1002/pd.1970110613] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A 39-year-old woman (G4P1SAB2) was referred for amniocentesis for advanced maternal age. An interstitial deletion of the G-dark band 11p12 was found in the fetus. Blood from the mother and her previous son was cultured and the same deletion was found in both. The absence of phenotypic effect in this family further confirms that G-dark euchromatic deletions are compatible with a normal phenotype, and underlines the importance of checking familial karyotypes even when apparently unbalanced structural rearrangements are found at prenatal diagnosis.
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Affiliation(s)
- J C Barber
- Kennedy-Galton Centre for Clinical Genetics, Northwick Park Hospital, Harrow, Middlesex, UK
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33
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Power MM. The first description of a balanced reciprocal translocation [t(1q;3q)] and its clinical effects in a mare. Equine Vet J 1991; 23:146-9. [PMID: 2044510 DOI: 10.1111/j.2042-3306.1991.tb02742.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- M M Power
- Irish Equine Centre, Naas, County Kildare, Ireland
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34
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Abuelo DN, Barsel-Bowers G, Richardson A. Insertional translocations: report of two new families and review of the literature. AMERICAN JOURNAL OF MEDICAL GENETICS 1988; 31:319-29. [PMID: 2852898 DOI: 10.1002/ajmg.1320310209] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We describe two families with insertional translocations. In the first, a large family ascertained because of repeated pregnancy loss, the insertional translocation, ins(1;3)(q32;p13pter), was found to be segregating through three generations. In the second family, ascertained through a proposita with congenital malformations, multiple spontaneous abortions also occurred. The father had an insertional translocation, inv 4(p14,q21.1)ins(7,4)(q32;q21.1 q23). These cases illustrate that recurrent fetal wastage may be caused by insertional translocations and in fact may be the only clinical manifestation of this unusual type of chromosome rearrangement.
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MESH Headings
- Chromosomes, Human, Pair 1
- Chromosomes, Human, Pair 3
- Chromosomes, Human, Pair 4
- Chromosomes, Human, Pair 7
- DNA Transposable Elements
- Female
- Humans
- Infant, Newborn
- Karyotyping
- Male
- Pedigree
- Translocation, Genetic
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Affiliation(s)
- D N Abuelo
- Genetic Counseling Center, Rhode Island Hospital, Department of Pediatrics, Providence 02902
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35
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Johnson DD, Dobyns WB, Gordon H, Dewald GW. Familial pericentric and paracentric inversions of chromosome 1. Hum Genet 1988; 79:315-20. [PMID: 3410456 DOI: 10.1007/bf00282168] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We investigated 33 individuals (21 carriers) from one family with a pericentric inversion involving a large part of chromosome 1 (1p36.1----1q32). In addition, we investigated 15 individuals (10 carriers) from another family with a paracentric inversion of a small part of chromosome 1 (1p32----1p36.1). In each family, the index patient was ascertained because three miscarriages had occurred. Each carrier of these inversions was phenotypically normal. If the miscarriages of the index patients are excluded, the frequency of recognized miscarriages among the carriers of childbearing age was 9% (4 of 46) for the family with pericentric inversion and 17% (4 of 23) for the family with paracentric inversion. One of the pericentric inv(1) carriers had had a stillborn daughter. The carriers of the pericentric inversion who were of childbearing age had 41 children; carriers of the paracentric inversion who were of childbearing age had 19 children. No live-born children with birth defects were observed in either family. This evidence, together with the low frequency of miscarriages, suggests that crossover within the inversion loop occurs much less frequently than might be expected from the large size of this inversion. Our investigation suggests that the risk of recognized miscarriages, stilbirths, and live-born children with recombinant chromosomes who have birth defects may be much lower for inv(1) carriers than previously reported. The risk of having a malformed child because of a recombinant chromosome is probably less than 3% for carriers of the pericentric inversion and less than 6% for the carriers of the paracentric inversion.
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Affiliation(s)
- D D Johnson
- Department of Medical Genetics, Mayo Clinic, Rochester, MN 55905
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36
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Bowser-Riley SM, Griffiths MJ, Creasy MR, Farndon PA, Martin KE, Thomson DA, Larkins SA, Johnson RA, Watt JL. Are double translocations double trouble? J Med Genet 1988; 25:326-31. [PMID: 3290489 PMCID: PMC1050459 DOI: 10.1136/jmg.25.5.326] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Double translocation heterozygotes are rare, but need not necessarily pose more of a counselling problem than single reciprocal translocation heterozygotes. Nine cases of double translocation are presented, together with a review of the few reports published to date. An attempt is made to provide simple counselling guidelines in the assessment of the risk of producing a liveborn abnormal child. This is not based on theoretical considerations of segregation patterns, but extrapolated from what is known empirically about the viable segregation patterns in carriers of single reciprocal translocations. It assumes that there is no interference with the independent assortment of the two separate exchanges, unless a common participating chromosome is involved. The possibility of an interchromosomal effect has not been taken into consideration.
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Affiliation(s)
- S M Bowser-Riley
- Regional Cytogenetics Unit, Birmingham Maternity Hospital, Edgbaston
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37
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Gorski JL, Kistenmacher ML, Punnett HH, Zackai EH, Emanuel BS. Reproductive risks for carriers of complex chromosome rearrangements: analysis of 25 families. AMERICAN JOURNAL OF MEDICAL GENETICS 1988; 29:247-61. [PMID: 3354596 DOI: 10.1002/ajmg.1320290202] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We have determined the empirical reproductive risks for heterozygous carriers of complex chromosome rearrangements (CCRs). CCRs are structural rearrangements involving at least three chromosomes and three or more chromosomal breakpoints. Pregnancy outcome, the frequency and type of chromosomal imbalance in the offspring, and the localization and distribution of chromosome breakpoints were analyzed in 25 CCR families ascertained by the birth of a malformed child or repeated spontaneous abortions. This study included two newly ascertained familial CCRs and a total of 67 informative pregnancies. Analysis of the data, after correction for ascertainment bias, showed that the incidence of spontaneous abortions in CCR families was 48.3%. Approximately one in ten pregnancies and 18.4% of all live births to CCR carriers resulted in phenotypically abnormal offspring. One-half of all CCR carrier liveborn offspring were also CCR carriers. There was a 53.7% incidence of an abnormal pregnancy outcome to CCR carriers. We failed to detect any evidence for a non-random involvement of specific chromosomes in CCRs. However, we did observe a non-random distribution of specific breakpoints at sites 1q25, 4q13, 6q27, 7p14, 9q12, 11p11, 11p15, 12q21, 13q31, and 18q21.
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Affiliation(s)
- J L Gorski
- Clinical Genetics Center, Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine
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Daniel A, Boué A, Gallano P. Prospective risk in reciprocal translocation heterozygotes at amniocentesis as determined by potential chromosome imbalance sizes. Data of the European Collaborative Prenatal Diagnosis Centres. Prenat Diagn 1986; 6:315-50. [PMID: 3774764 DOI: 10.1002/pd.1970060502] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The Date of the European Cooperative Prenatal Diagnosis Laboratories (Boué and Gallano, 1984) of 596 prenatal (amniocyte) diagnoses of familial rcp was examined as to relationships between balanced/unbalanced result and ascertainment, carrier parent and chromosome imbalance size (percentage haploid autosome length). Each rearrangement was graphed once with actual (unbalanced result) or potential (normal or balanced result) imbalances plotted with trisomy as the ordinate and monosomy as the abscissa. The graphed data was divided into 15 regions, each of 2.0 per cent trisomy and 0.75 per cent monosomy and the rate of unbalanced pregnancies determined for each region. The highest rates of chromosomally unbalanced progeny (excluding regions with inadequate data) were found closest to the origin (i.e. associated with the smallest imbalances) and these were for ascertainment category 1 (previous rcp unbalanced child) 22.3 per cent for maternal carriers and 39 per cent for paternal carriers. Overall in pooled data for this ascertainment category (without reference to the imbalance graphs) there were for paternal carriers 28.6 per cent unbalanced pregnancies and for maternal carriers 18.1 per cent. The graphed data, therefore, revealed the higher rates associated with some of the rcp with small potential (combined duplication/deficiency) imbalances. Lesser rates were observed for ascertainment category 2 (carrier parent with a history of recurrent miscarriage) with overall percentages of imbalanced progeny ranging from 2.7 (paternal carriers) to 4.7 (maternal carriers). Again, higher rates were revealed in graphed data for small potential imbalances. All unbalanced results for this group (ascertainment category 2) plotted in the region closest to the origin with rates of 16 per cent (maternal carriers) and 9.5 per cent (paternal carriers) in this region. Remarkably in both ascertainment groups 1 and 2 there was no significant difference in the size of the imbalanced segments for unbalanced progeny. In ascertainment group 1 this was (dup/def; mean +/- S.D.): 1.09 +/- 0.77/0.47 +/- 0.45 and in ascertainment group 2: 1.09 +/- 0.80/0.66 +/- 0.71. From the graphed data which arguably denote viability relationships, a trisomy was approximately 2.7 times as likely to survive until amniocentesis as a monosomy of equivalent size. It is proposed that given further data, risk estimates could be determined for rcp heterozygotes using the present approach where empiric data (from the family history or an analysed series of similar rcp) is not available.
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De Arce MA, Grace PM, McManus S. A computer model for the study of segregation in reciprocal translocation carriers: application to 20 new cases. AMERICAN JOURNAL OF MEDICAL GENETICS 1986; 24:519-25. [PMID: 3755291 DOI: 10.1002/ajmg.1320240315] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We report on a computer program that, given the breakpoints and the chromosomes involved in a translocation, generates all the possible imbalanced gametes, calculates their corresponding imbalances, and arranges them in order of increasing imbalance. When compared to current, more cumbersome criteria from the literature, both methods agreed on 196 cases of 199 (greater than 98%). When compared to observed data from families with aneuploid offspring, both our program and the other reported methods yield a rate of accurate prediction of 87%. The use of the program is illustrated in 20 new translocations from our laboratory. The possible influence of crossing over in meiosis I in altering the gamete that is most likely to be passed to aneuploid live births is discussed.
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MESH Headings
- Abortion, Spontaneous/genetics
- Chromosome Aberrations
- Chromosomes, Human, 1-3
- Chromosomes, Human, 13-15
- Chromosomes, Human, 16-18
- Chromosomes, Human, 6-12 and X
- Female
- Genetic Counseling
- Humans
- Karyotyping
- Mosaicism
- Pregnancy
- Recurrence
- Translocation, Genetic
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Campana M, Serra A, Neri G. Role of chromosome aberrations in recurrent abortion: a study of 269 balanced translocations. AMERICAN JOURNAL OF MEDICAL GENETICS 1986; 24:341-56. [PMID: 3717213 DOI: 10.1002/ajmg.1320240214] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We have studied a sample of 5,445 couples in which the woman was ascertained to have had two or more spontaneous abortions: 396 from our Cytogenetics Unit (present series) and 5,049 from the literature (literature series). In approximately 5% of these couples one of the members was a carrier of a balanced translocation, either reciprocal (2/3 of cases) or Robertsonian (1/3). In 1% of the couples there were other chromosome anomalies, mostly gonosomal aneuploidies or mosaicisms. A pericentric inversion of the heterochromatic region of chromosome 9 was present in 3% of the couples of the present series and in 1% of the literature series. The number of female carriers exceeded significantly that of males. The probability for one member of the couple to be a carrier increased with the number of abortions at the time of ascertainment, but it does not seem modified by the concomitant presence of term pregnancies. The analysis of the cytogenetic findings in 80 cases of Robertsonian and 156 cases of reciprocal translocations suggests that some chromosomes are preferentially involved, and that in reciprocal translocations the breakpoints are not distributed at random on the chromosome arms. There is an excess of breakpoints on chromosomes 6, 7, and 22 and a dearth on chromosome 12. This distribution is significantly different from that of a sample of reciprocal translocations ascertained for a malformed child. In both samples the breakpoints seem associated with fragile sites more frequently than expected by chance. An analysis of the potential and effective chromosome imbalance suggests that in subjects with unbalanced chromosomes survival is correlated with a minimum imbalance.
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Priest JH, Lavett DK, Marion JP. Analysis of crossing-over in a family with translocation 9;10 involving a chromosome 9 with a pericentric inversion. Hum Genet 1985; 71:177-80. [PMID: 4043968 DOI: 10.1007/bf00283378] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The presence of two markers on chromosome 9, both a balanced reciprocal translocation and an inversion, allows morphologic demonstration of recombination between the normal and rearranged homologues. In the family under discussion 50% of the progeny studied (two of four) received a translocated 9 without the inversion from a parent with a translocated and inverted 9, indicating crossing-over between members of the chromosome 9 pair. Thus the morphology of the chromosomes allows a recombinant event which is normally invisible to be seen cytologically. Theoretically after crossing-over the balanced reciprocal translocation heterozygote results from adjacent-1 segregation and unbalanced derivative chromosome combinations from alternate segregation. Therefore it cannot be assumed that the balanced progeny necessarily result from alternate segregation and the unbalanced from adjacent-1. The prenatal diagnostic studies presented in this report also show that chromosome analysis of other family members is required when the recombination between homologues produces differences in chromosome morphology between parent and fetus.
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Daniel A. The size of prometaphase chromosome segments. Tables using percentages of haploid autosome length (750 band stage). Clin Genet 1985; 28:216-24. [PMID: 4064359 DOI: 10.1111/j.1399-0004.1985.tb00389.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Tables of prometaphase chromosome segment sizes (750 band stage) are presented in units of percentage of haploid autosome length designating the distances from interband borders to telomeres. The Tables utilize ISCN (1981) nomenclature.
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Bauer K, Howard-Peebles PN, Keele D, Friedman JM. Wolf-Hirschhorn syndrome owing to 1:3 segregation of a maternal 4;21 translocation. AMERICAN JOURNAL OF MEDICAL GENETICS 1985; 21:351-6. [PMID: 4014316 DOI: 10.1002/ajmg.1320210218] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We describe a child with Wolf-Hirschhorn syndrome with the karyotype 45,XY,inv(9)(p11q13)pat,-4,-21,+der(4),t(4;21)(p15.3;q11.2)mat. This is the second case known to us of Wolf-Hirschhorn syndrome caused by 1:3 segregation of a parental rearrangement. This mode of segregation can be predicted in both cases by a pachytene-diagram model. It is uncertain whether or not the proximal 21q monosomy in this case has affected the phenotype.
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Davis JR, Rogers BB, Hagaman RM, Thies CA, Veomett IC. Balanced reciprocal translocations: risk factors for aneuploid segregant viability. Clin Genet 1985; 27:1-19. [PMID: 3884190 DOI: 10.1111/j.1399-0004.1985.tb00179.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Reciprocal translocations were studied in two groups of balanced carrier couples: 202 had 210 translocation aneuploid between (LB) infants, and 95 couples had repetitive abortions (AB) without liveborn aneuploids. The observed translocation aneuploidies in the LB group were compared to predicted potential aneuploidies in AB by frequency of chromosome involvement, meiotic segregation mode, and mean trisomic, monosomic and combined genomic imbalances. Qualitative and quantitative differences identified genomic regions and chromosomes possibly vital for in utero survivability. LB aneuploidies indicate non-random chromosome involvement, selection of least detrimental segregants and segments, and predominant transmission from maternal balanced carriers (especially in 3:1 tertiary segregation, 93.5%). For an individual with a balanced reciprocal translocation and untested reproductive capability, an approach is given for predicting whether a translocation aneuploid conceptus will be liveborn or aborted.
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Evans MI, White BJ, Kent SG, Levine MA, Levin SW, Larsen JW. Balanced rearrangement of chromosomes 2, 5, and 13 in a family with duplication 5q and fetal loss. AMERICAN JOURNAL OF MEDICAL GENETICS 1984; 19:783-90. [PMID: 6517101 DOI: 10.1002/ajmg.1320190419] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
We have studied a family in which a mother and daughter (the proposita) had the karyotype 46,XX,ins(2;5),t(5;13). The mother had four spontaneous abortions, a mentally retarded son with duplication (5q), and a daughter who died at 3 months. The proposita had a phenotypically abnormal abortus. Rearrangements involving several chromosomes are very rare. Observations on this family are consistent with the predicted high likelihood of reproductive loss.
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Boué A, Gallano P. A collaborative study of the segregation of inherited chromosome structural rearrangements in 1356 prenatal diagnoses. Prenat Diagn 1984; 4 Spec No:45-67. [PMID: 6463033 DOI: 10.1002/pd.1970040705] [Citation(s) in RCA: 186] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
A collaborative study involving 71 European prenatal diagnosis centres has collected 1356 observations on the karyotype of fetal cells in diagnoses performed in couples in which a parent had a balanced structural rearrangement. The segregations of the inherited chromosome structural rearrangement were analysed in relation to the types of rearrangement, to the sex of the carrier parent, the methods of ascertainment of the anomaly in the family, the chromosomes involved and the potential imbalance of the anomaly. Wide differences in the incidence of unbalanced fetuses were observed in relation to these criteria, and these results can be used in counselling parents with balanced rearrangements. Distortions in segregation of normal versus balanced karyotypes were observed in some types of anomalies.
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Petrosky DL, Borgaonkar DS. Segregation analysis in reciprocal translocation carriers. AMERICAN JOURNAL OF MEDICAL GENETICS 1984; 19:137-59. [PMID: 6496566 DOI: 10.1002/ajmg.1320190115] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Segregation analysis of the offspring of balanced translocation carriers was performed on 327 pedigrees collated from published sources and personal communications. Correction was made for bias of ascertainment. Translocations studied involved chromosome arms 1p, 4q, 6p, 6q, 7p, 8p, 10p, 10q, 11q, 14q, 16q, and 17p. Findings included similar rates of occurrence of abnormal liveborn offspring in male and female carriers except for a reduction of risk in male carriers of translocations segregating by 3:1 mode; an elevated risk of fetal loss (spontaneous abortions and stillbirths) in female carriers of 6q, 11q, and 16q translocations compared to male carriers of these translocations; a fetal loss rate exceeding general population estimates in female carriers of 6q and 10q translocations and in male carriers of 6p, 8p, 10q, and 14q translocations including a rate of nearly 50% among female 6q translocation carriers; a higher than expected number of balanced carriers among liveborn offspring; and a low risk of abnormal liveborn children among carriers ascertained by means other than through unbalanced probands. We propose that some translocation carriers may be helped by consideration of more specific empiric risk figures than have traditionally been used.
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Kitsiou-Tzeli S, Hallett JJ, Atkins L, Latt SA, Holmes LB. Familial t (4;21)(q2.4;q2.2) leading to unbalanced offspring with partial duplication of 4q and of 21q without manifestations of the Down syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 1984; 18:725-9. [PMID: 6237580 DOI: 10.1002/ajmg.1320180419] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We report on an infant with a malformation syndrome who had a combination of partial duplication of 4q and 21q as the result of a maternal unbalanced translocation. She has duplication of the proximal portion of chromosome 21, without manifestation of the Down syndrome.
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