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Ouyang L, Li Y, Liu F, Zeng Q. Prenatal diagnosis and genetic counseling of a de novo 10q11.21q11.23 duplication associated with a normal phenotype. J Int Med Res 2024; 52:3000605241271837. [PMID: 39175233 PMCID: PMC11344892 DOI: 10.1177/03000605241271837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Accepted: 06/24/2024] [Indexed: 08/24/2024] Open
Abstract
Copy number variants (CNVs) are an important source of normal and pathogenic genome variations. Unbalanced chromosome abnormalities are either gains or losses of large genomic regions that do not or only minimally clinically affect the individual. Noninvasive prenatal testing (NIPT) is widely used in the screening of common fetal chromosome aneuploidy. One example is the duplication of 10q11.21q11.23, which includes the 10q11.2 region. This region contains a complex set of low-copy repeats that may lead to various genomic alterations through non-allelic homologous recombination. In this report, we present a case of a de novo 10q11.21q11.23 duplication with a normal phenotype. This case may be helpful for prenatal diagnosis and genetic counseling. A combination of NIPT, prenatal ultrasound, karyotype analysis, copy number variation sequencing, and genetic counseling is helpful for the prenatal diagnosis of CNVs.
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Affiliation(s)
| | | | - Fangfang Liu
- Department of Obstetrics, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, PR China
| | - Qin Zeng
- Department of Obstetrics, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, PR China
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2
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Zhang Y, Chen J, Feng Z, Li W. Prenatal diagnosis and genetic counseling of an inherited unbalanced chromosome abnormalities in a Chinese family. Mol Cytogenet 2022; 15:34. [PMID: 35971114 PMCID: PMC9380353 DOI: 10.1186/s13039-022-00614-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 08/03/2022] [Indexed: 11/24/2022] Open
Abstract
Background Unbalanced chromosome abnormalities (UBCA) are either gains or losses or large genomic regions, but the affected person is not or only minimally clinically affected. Copy number variants (CNVs) are an important source of normal and pathogenic genome variations. CNVs and UBCA identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm. Case presentation A 25-year-old, gravida 1, para 0, woman underwent amniocentesis at 18 weeks of gestation because the noninvasive prenatal testing (NIPT) results revealed a 6.8 Mb duplication from 2q11.1 to 2q11.2. Chromosomal microarray analysis (CMA) was performed on uncultured amniocytes. GTG-banding karyotype analysis on cultured amniocytes was performed. Results Chromosomal GTG-banding of the cultured amniocytes revealed a karyotype of 46,XX. CMA detected a 6.8-Mb chromosomal duplication in the region of 2q11.1q11.2 (arr[GRCh37] 2q11.1q11.2(95,327,873_102,088,148)x3). Conclusion Chromosomal microdeletions and microduplications are difficult to detect by conventional cytogenetics, combination of prenatal ultrasound, karyotype analysis, NIPT, CMA and genetic counseling is helpful for the prenatal diagnosis of UBCA and chromosomal microdeletions/microduplications.
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Affiliation(s)
- Ying Zhang
- Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China.,Prenatal Diagnosis Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China.,Hubei Clinical Research Center for Reproductive Medicine, Shiyan, Hubei, People's Republic of China.,Biomedical Engineering College, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China
| | - Juan Chen
- Reproductive Medicine Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China.,Prenatal Diagnosis Center, Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China.,Hubei Clinical Research Center for Reproductive Medicine, Shiyan, Hubei, People's Republic of China.,Biomedical Engineering College, Hubei University of Medicine, Shiyan, Hubei, People's Republic of China
| | - Zonghui Feng
- Prenatal Diagnosis Center, Maternity and child Care Hospital of Huaihua, Huaihua, Hunan, People's Republic of China
| | - Wencheng Li
- Prenatal Diagnosis Center, Maternity and child Care Hospital of Huaihua, Huaihua, Hunan, People's Republic of China.
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3
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Song J, Jiang W, Zhang C, Wang B. Prenatal diagnosis and genetic counseling of a 10p11.23q11.21 duplication associated with normal phenotype. Mol Cytogenet 2022; 15:21. [PMID: 35659699 PMCID: PMC9164483 DOI: 10.1186/s13039-022-00598-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Accepted: 05/11/2022] [Indexed: 11/13/2022] Open
Abstract
Background Copy number variants (CNVs) are an important source of normal and pathogenic genome variations. Unbalanced chromosome abnormalities (UBCA) are either gains or losses or large genomic regions, but the affected person is not or only minimally clinically affected. CNVs and UBCA identified in prenatal cases need careful considerations and correct interpretation if those are harmless or harmful variants from the norm. Case presentation A 24-year-old, gravida 1, para 0, woman underwent amniocentesis at 17 weeks of gestation because the noninvasive prenatal testing (NIPT) results revealed a 12.4 Mb duplication from 10p11.2 to 10q11.2. GTG-banding karyotype analysis was performed on cultured amniocytes. Chromosomal microarray analysis (CMA) on uncultured amniocytes was performed. Results Chromosomal GTG-banding of the cultured amniocytes revealed a karyotype of 46,XX,dup(10)(p11.2q11.2). CMA detected a 12.5-Mb chromosomal duplication in the region of 10p11.23q11.21 (arr[GRCh37] 10p11.23q11.21(30,345,109_42,826,062) × 3). Conclusion The present report enlarges the known UBCA region 10p11.22-10q11.22 to 10p11.23-10q11.22. Also it highlights that an integration of prenatal ultrasound, NIPT, karyotype analysis, CMA and genetic counseling is helpful for the prenatal diagnosis of chromosomal deletions/duplications.
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Affiliation(s)
- Jieping Song
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Wei Jiang
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Chengcheng Zhang
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Bo Wang
- Department of Clinical Laboratory, Maternal and Child Health Hospital of Hubei Province, Wuhan, Hubei, People's Republic of China.
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Barranco L, Costa M, Lloveras E, Ordóñez E, Maiz N, Hernando C, Villa O, Cirigliano V, Plaja A. Three-Year Follow-Up of a Prenatally Ascertained Apparently Non-Mosaic sSMC(10): Delineation of a Non-Critical Region. Cytogenet Genome Res 2016; 147:209-11. [PMID: 26974471 DOI: 10.1159/000444600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2015] [Indexed: 11/19/2022] Open
Abstract
Small supernumerary marker chromosomes (sSMC) originating from chromosome 10 are rare and usually found in mosaic form. We present a de novo apparently non-mosaic sSMC(10) prenatally diagnosed in amniotic fluid and postnatally confirmed in peripheral blood. Characterization by array-CGH showed a pericentromeric duplication of 7.1 Mb of chromosome 10. The fetus did not show ultrasound abnormalities, and a normal female phenotype was observed during a 3-year postnatal follow-up. The absence of phenotypic abnormalities in the present case provides evidence of a non-critical pericentromeric region in 10p11.21q11.1 (hg19 35,355,570-42,448,569) associated with a duplication.
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Affiliation(s)
- Laura Barranco
- Departament de Citogenx00E8;tica, LABCO Diagnostics Iberia, Esplugues de Llobregat, Spain
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5
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Bakalar D, Tamaiev J, Zeigler HP, Feinstein P. Abolition of lemniscal barrellette patterning in Prrxl1 knockout mice: Effects upon ingestive behavior. Somatosens Mot Res 2015; 32:236-48. [PMID: 26402339 DOI: 10.3109/08990220.2015.1086327] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Ingestive behaviors in mice are dependent on orosensory cues transmitted via the trigeminal nerve, as confirmed by transection studies. However, these studies cannot differentiate between deficits caused by the loss of the lemniscal pathway vs. the parallel paralemniscal pathway. The paired-like homeodomain protein Prrxl1 is expressed widely in the brain and spinal cord, including the trigeminal system. A knockout of Prrxl1 abolishes somatotopic barrellette patterning in the lemniscal brainstem nucleus, but not in the parallel paralemniscal nucleus. Null animals are significantly smaller than littermates by postnatal day 5, but reach developmental landmarks at appropriate times, and survive to adulthood on liquid diet. A careful analysis of infant and adult ingestive behavior reveals subtle impairments in suckling, increases in time spent feeding and the duration of feeding bouts, feeding during inappropriate times of the day, and difficulties in the mechanics of feeding. During liquid diet feeding, null mice display abnormal behaviors including extensive use of the paws to move food into the mouth, submerging the snout in the diet, changes in licking, and also have difficulty consuming solid chow pellets. We suggest that our Prrxl1(-/-) animal is a valuable model system for examining the genetic assembly and functional role of trigeminal lemniscal circuits in the normal control of eating in mammals and for understanding feeding abnormalities in humans resulting from the abnormal development of these circuits.
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Affiliation(s)
- Dana Bakalar
- a Department of Psychology , Hunter College, City University of New York , New York , USA and
| | - Jonathan Tamaiev
- a Department of Psychology , Hunter College, City University of New York , New York , USA and
| | - H Philip Zeigler
- a Department of Psychology , Hunter College, City University of New York , New York , USA and
| | - Paul Feinstein
- b Department of Biological Sciences and The Graduate Center Biochemistry , Biology and Biopsychology and Behavioral Neuroscience Programs, Hunter College, City University of New York , New York , USA
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Al-Qattan SM, Wakil SM, Anazi S, Alazami AM, Patel N, Shaheen R, Shamseldin HE, Hagos ST, AlDossari HM, Salih MA, El Khashab HY, Kentab AY, AlNasser MN, Bashiri FA, Kaya N, Hashem MO, Alkuraya FS. The clinical utility of molecular karyotyping for neurocognitive phenotypes in a consanguineous population. Genet Med 2014; 17:719-25. [PMID: 25503496 DOI: 10.1038/gim.2014.184] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/11/2014] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Molecular karyotyping has rapidly become the test of choice in patients with neurocognitive phenotypes, but studies of its clinical utility have largely been limited to outbred populations. In consanguineous populations, single-gene recessive causes of neurocognitive phenotypes are expected to account for a relatively high percentage of cases, thus diminishing the yield of molecular karyotyping. The aim of this study was to test the clinical yield of molecular karyotyping in the highly consanguineous population of Saudi Arabia. METHODS We have reviewed the data of 584 patients with neurocognitive phenotypes (mainly referred from pediatric neurology clinics), all evaluated by a single clinical geneticist. RESULTS At least 21% of tested cases had chromosomal aberrations that are likely disease-causing. These changes include both known and novel deletion syndromes. The higher yield of molecular karyotyping in this study as compared with the commonly cited 11% can be explained by our ability to efficiently identify single-gene disorders, thus enriching the samples that underwent molecular karyotyping for de novo chromosomal aberrations. We show that we were able to identify a causal mutation in 37% of cases on a clinical basis with the help of autozygome analysis, thus bypassing the need for molecular karyotyping. CONCLUSION Our study confirms the clinical utility of molecular karyotyping even in highly consanguineous populations.
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Affiliation(s)
- Sarah M Al-Qattan
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Salma M Wakil
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Shamsa Anazi
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Anas M Alazami
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Nisha Patel
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Ranad Shaheen
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Hanan E Shamseldin
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Samya T Hagos
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Haya M AlDossari
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Heba Y El Khashab
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia.,Department of Pediatrics, Children Hospital, Ain Shams University, Cairo, Egypt
| | - Amal Y Kentab
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Mohammed N AlNasser
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Fahad A Bashiri
- Division of Pediatric Neurology, Department of Pediatrics, King Khalid University Hospital and College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Namik Kaya
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mais O Hashem
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Fowzan S Alkuraya
- Department of Genetics, Research Center, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.,Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
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7
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Manolakos E, Vetro A, Garas A, Thomaidis L, Kefalas K, Kitsos G, Ziegler M, Liehr T, Zuffardi O, Papoulidis I. Proximal 10q duplication in a child with severe central hypotonia characterized by array-comparative genomic hybridization: A case report and review of the literature. Exp Ther Med 2014; 7:953-957. [PMID: 24669257 PMCID: PMC3964923 DOI: 10.3892/etm.2014.1520] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 01/08/2014] [Indexed: 11/05/2022] Open
Abstract
Proximal 10q duplication is a well-defined but rare genetic syndrome. Duplication of proximal segments of the long arm of chromosome 10 results in a pattern of malformations, which are distinct from those of the more common distal 10q trisomy syndrome. The present study describes the case of a boy with phenotypic abnormalities (severe central hypotonia, mild ataxia, moderate developmental delay and mild dysmorphic features), due to duplication of chromosome region, 10q11.21→q11.22, which was characterized by the array-comparative genomic hybridization (CGH) technique. The phenotypic findings were compared with those in eight additional similar published cases. Major similarities have emerged, suggesting a likely minimal critical region. However, only detailed characterization of additional cases may provide firm conclusions.
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Affiliation(s)
| | - Annalisa Vetro
- Department of Human and Hereditary Pathology, University of Pavia, Pavia 27100, Italy
| | - Antonios Garas
- Department of Gynecology, Larissa Medical School, University of Thessaly, Larissa 41335, Greece
| | - Loretta Thomaidis
- Developmental Assessment Unit, Second Department of Paediatrics, P&A Kyriakou Children's Hospital, University of Athens, Athens 11527, Greece
| | | | - George Kitsos
- Department of Ophthalmology, University of Ioannina, Ioannina 45110, Greece
| | - Monika Ziegler
- Institute of Human Genetics and Anthropology, Jena University Hospital, Jena D-07743, Germany
| | - Thomas Liehr
- Institute of Human Genetics and Anthropology, Jena University Hospital, Jena D-07743, Germany
| | - Orsetta Zuffardi
- Department of Human and Hereditary Pathology, University of Pavia, Pavia 27100, Italy
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8
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Castronovo C, Valtorta E, Crippa M, Tedoldi S, Romitti L, Amione MC, Guerneri S, Rusconi D, Ballarati L, Milani D, Grosso E, Cavalli P, Giardino D, Bonati MT, Larizza L, Finelli P. Design and validation of a pericentromeric BAC clone set aimed at improving diagnosis and phenotype prediction of supernumerary marker chromosomes. Mol Cytogenet 2013; 6:45. [PMID: 24171812 PMCID: PMC4176193 DOI: 10.1186/1755-8166-6-45] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 10/08/2013] [Indexed: 12/17/2022] Open
Abstract
Background Small supernumerary marker chromosomes (sSMCs) are additional, structurally abnormal chromosomes, generally smaller than chromosome 20 of the same metaphase spread. Due to their small size, they are difficult to characterize by conventional cytogenetics alone. In regard to their clinical effects, sSMCs are a heterogeneous group: in particular, sSMCs containing pericentromeric euchromatin are likely to be associated with abnormal outcomes, although exceptions have been reported. To improve characterization of the genetic content of sSMCs, several approaches might be applied based on different molecular and molecular-cytogenetic assays, e.g., fluorescent in situ hybridization (FISH), array-based comparative genomic hybridization (array CGH), and multiplex ligation-dependent probe amplification (MLPA). To provide a complementary tool for the characterization of sSMCs, we constructed and validated a new, FISH-based, pericentromeric Bacterial Artificial Chromosome (BAC) clone set that with a high resolution spans the most proximal euchromatic sequences of all human chromosome arms, excluding the acrocentric short arms. Results By FISH analysis, we assayed 561 pericentromeric BAC probes and excluded 75 that showed a wrong chromosomal localization. The remaining 486 probes were used to establish 43 BAC-based pericentromeric panels. Each panel consists of a core, which with a high resolution covers the most proximal euchromatic ~0.7 Mb (on average) of each chromosome arm and generally bridges the heterochromatin/euchromatin junction, as well as clones located proximally and distally to the core. The pericentromeric clone set was subsequently validated by the characterization of 19 sSMCs. Using the core probes, we could rapidly distinguish between heterochromatic (1/19) and euchromatic (11/19) sSMCs, and estimate the euchromatic DNA content, which ranged from approximately 0.13 to more than 10 Mb. The characterization was not completed for seven sSMCs due to a lack of information about the covered region in the reference sequence (1/19) or sample insufficiency (6/19). Conclusions Our results demonstrate that this pericentromeric clone set is useful as an alternative tool for sSMC characterization, primarily in cases of very small SMCs that contain either heterochromatin exclusively or a tiny amount of euchromatic sequence, and also in cases of low-level or cryptic mosaicism. The resulting data will foster knowledge of human proximal euchromatic regions involved in chromosomal imbalances, thereby improving genotype–phenotype correlations.
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Affiliation(s)
- Chiara Castronovo
- Laboratorio di Citogenetica Medica e Genetica Molecolare, IRCCS Istituto Auxologico Italiano, via Ariosto 13, 20145, Milano, Italy.
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9
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Abstract
Centromere-near gain of copy number can be induced by intra- or inter-chromosomal rearrangements or by the presence of a small supernumerary marker chromosome (sSMC). Interestingly, partial trisomy to hexasomy of euchromatic material may be present in clinically healthy or affected individuals, depending on origin and size of chromosomal material involved. Here we report the known minimal sizes of all centromere-near, i.e., proximal auto-somal regions in humans, which are tolerated; over 100 Mb of coding DNA are comprised in these regions. Additionally, we have summarized the typical symptoms for nine proximal autosomal regions including genes obviously sensitive to copy numbers. Overall, studying the carriers of specific chromosomal imbalances using genomics-based medicine, combined with single cell analysis can provide the genotype-phenotype correlations and can also give hints where copy-number-sensitive genes are located in the human genome.
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10
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Ou J, Wang W, Liehr T, Klein E, Hamid AB, Wang F, Duan C, Li H. Characterization of three small supernumerary marker chromosomes (sSMC) in humans. J Matern Fetal Neonatal Med 2012; 26:106-8. [PMID: 23013067 DOI: 10.3109/14767058.2012.732129] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
In the present study, three prenatally detected small supernumerary marker chromosomes (sSMC) were identified by banding cytogenetics and characterized in detail by molecular cytogenetics. In one case an sSMC(10) leading to a pericentric partial trisomy and in two cases heterochromatic sSMC derived from chromosome 22 were characterized. Outcomes were reportedly normal for two of the three cases for whom this information was known.
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Affiliation(s)
- Jian Ou
- Nanjing Medical University Affiliated Suzhou Hospital, Suzhou Municipal Hospital, Jiangsu, China
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11
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McGrew SG, Peters BR, Crittendon JA, Veenstra-VanderWeele J. Diagnostic Yield of Chromosomal Microarray Analysis in an Autism Primary Care Practice: Which Guidelines to Implement? J Autism Dev Disord 2011; 42:1582-91. [DOI: 10.1007/s10803-011-1398-3] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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12
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New cytogenetically visible copy number variant in region 8q21.2. Mol Cytogenet 2011; 4:1. [PMID: 21208402 PMCID: PMC3024988 DOI: 10.1186/1755-8166-4-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 01/05/2011] [Indexed: 12/02/2022] Open
Abstract
Background Cytogenetically visible unbalanced chromosomal abnormalities (UBCA), reported for >50 euchromatic regions of almost all human autosomes, are comprised of a few megabases of DNA, and carriers are in many cases clinically healthy. It may be speculated, that some of the UBCA may be similar or identical to copy number variants (CNV) of the human genome. Results Here we report on a yet unreported cytogenetically visible copy number variant (CNV) in the long arm of chromosome 8, region 8q21.2, detected in three unrelated clinically healthy carriers. Conclusion The first description of a cytogenetically visible CNV/UBCA in 8q21.2 shows that banding cytogenetics is far from being outdated. It is a cost efficient, up-to-date method for a single cell specific overview on the whole genome, still prepared to deliver unexpected findings.
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13
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Manolakos E, Vetro A, Kefalas K, Rapti SM, Louizou E, Garas A, Kitsos G, Vasileiadis L, Tsoplou P, Eleftheriades M, Peitsidis P, Orru S, Liehr T, Petersen MB, Thomaidis L. The use of array-CGH in a cohort of Greek children with developmental delay. Mol Cytogenet 2010; 3:22. [PMID: 21062444 PMCID: PMC2987877 DOI: 10.1186/1755-8166-3-22] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 11/09/2010] [Indexed: 11/14/2022] Open
Abstract
Background The genetic diagnosis of mental retardation (MR) is difficult to establish and at present many cases remain undiagnosed and unexplained. Standard karyotyping has been used as one of the routine techniques for the last decades. The implementation of Array Comparative Genomic Hybridization (array-CGH) has enabled the analysis of copy number variants (CNVs) with high resolution. Major cohort studies attribute 11% of patients with unexplained mental retardation to clinically significant CNVs. Here we report the use of array-CGH for the first time in a Greek cohort. A total of 82 children of Greek origin with mean age 4.9 years were analysed in the present study. Patients with visible cytogenetic abnormalities ascertained by standard karyotyping as well as those with subtelomeric abnormalities determined by Multiplex Ligation-dependent Probe Amplification (MLPA) or subtelomeric FISH had been excluded. Results Fourteen CNVs were detected in the studied patients. In nine patients (11%) the chromosomal aberrations were inherited from one of the parents. One patients showed two duplications, a 550 kb duplication in 3p14.1 inherited from the father and a ~1.1 Mb duplication in (22)(q13.1q13.2) inherited from the mother. Although both parents were phenotypically normal, it cannot be excluded that the dual duplication is causative for the patient's clinical profile including dysmorphic features and severe developmental delay. Furthermore, three de novo clinically significant CNVs were detected (3.7%). There was a ~6 Mb triplication of 18q21.1 in a girl 5 years of age with moderate MR and mild dysmorphic features and a ~4.8 Mb duplication at (10)(q11.1q11.21) in a 2 years old boy with severe MR, multiple congenital anomalies, severe central hypotonia, and ataxia. Finally, in a 3 year-old girl with microcephaly and severe hypotonia a deletion in (2)(q31.2q31.3) of about ~3.9 Mb was discovered. All CNVs were confirmed by Fluorescence in situ hybridization (FISH). For the remaining 9 patients the detected CNVs (inherited duplications or deletions of 80 kb to 800 kb in size) were probably not associated with the clinical findings. Conclusions Genomic microarrays have within the recent years proven to be a highly useful tool in the investigation of unexplained MR. The cohorts reported so far agree on an around 11% diagnostic yield of clinically significant CNVs in patients with unexplained MR. Various publicly available databases have been created for the interpretation of identified CNVs and parents are analyzed in case a rare CNV is identified in the child. We have conducted a study of Greek patients with unexplained MR and confirmed the high diagnostic value of the previous studies. It is important that the technique becomes available also in less developed countries when the cost of consumables will be reduced.
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Tirado CA, Henderson S, Uddin N, Stewart E, Iyer S, Ratner IM, Matthews E, Doolittle J, Garcia R, Valdez F, Dallaire S, Appleberry T, Payne D, Collins R. Cytogenetic and molecular characterization of a partial trisomy 2p arising from inverted duplication of 2p with terminal deletion of 2pter. Am J Med Genet A 2009; 149A:2507-12. [DOI: 10.1002/ajmg.a.33080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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