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Saberi M, Mahjoub F. Simultaneous 9p Deletion and 8p Duplication in a Seven-Year-Old Girl, Detected Using Multiplex Ligation-Dependent Probe Amplification: A Case Report. IRANIAN JOURNAL OF MEDICAL SCIENCES 2022; 47:494-499. [PMID: 36117579 PMCID: PMC9445862 DOI: 10.30476/ijms.2021.89353.2039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 05/19/2021] [Accepted: 08/20/2021] [Indexed: 11/17/2022]
Abstract
Deletion 9p syndrome is a rare chromosomal abnormality with a wide spectrum of manifestations such as craniofacial dysmorphism, congenital anomalies, and psychomotor delay. We report a case of a seven-year-old girl with simultaneous 9p24.3 deletion and 8p23.3 duplication detected using multiplex ligation-dependent probe amplification (MLPA). Chromosomal and cytogenetic analyses using MLPA are effective in assessing genetic abnormalities in patients with developmental delay and mental retardation. We found breakpoints at 9p24.3 and duplication in the 8p23.3 region, leading to a wide variety of manifestations including speech delay, upslanting palpebral fissures, hypertelorism, epicanthal fold, high arched eyebrows, flat nasal bridge, thin upper lip, and cleft palate. Simultaneous detection of 9p24.3 deletion and 8p23.3 duplication has been rarely reported. Clinical phenotypes of our patient resembled the features of Nicolaides-Baraitser syndrome, which might have been primarily caused by the haploinsufficiency of SMARCA2 (SWI/SNF-related, matrix associated, actin-dependent regulator of chromatin, subfamily A, member 2) gene located at 9p24.3.
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Affiliation(s)
- Mozhgan Saberi
- Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotecnology, Tehran, Iran
| | - Frouzandehi Mahjoub
- Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotecnology, Tehran, Iran
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Hu X, Baker EK, Johnson J, Balow S, Pena LDM, Conlin LK, Guan Q, Smolarek TA. Characterization of a rare mosaic unbalanced translocation of t(3;12) in a patient with neurodevelopmental disorders. Mol Cytogenet 2022; 15:10. [PMID: 35248119 PMCID: PMC8898488 DOI: 10.1186/s13039-022-00579-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 01/28/2022] [Indexed: 11/21/2022] Open
Abstract
Background Unbalanced translocations may be de novo or inherited from one parent carrying the balanced form and are usually present in all cells. Mosaic unbalanced translocations are extremely rare with a highly variable phenotype depending on the tissue distribution and level of mosaicism. Mosaicism for structural chromosomal abnormalities is clinically challenging for diagnosis and counseling due to the limitation of technical platforms and complex mechanisms, respectively. Here we report a case with a tremendously rare maternally-derived mosaic unbalanced translocation of t(3;12), and we illustrate the unreported complicated mechanism using single nucleotide polymorphism (SNP) array, fluorescence in situ hybridization (FISH), and chromosome analyses. Case presentation An 18-year-old female with a history of microcephaly, pervasive developmental disorder, intellectual disability, sensory integration disorder, gastroparesis, and hypotonia presented to our genetics clinic. She had negative karyotype by parental report but no other genetic testing performed previously. SNP microarray analysis revealed a complex genotype including 8.4 Mb terminal mosaic duplication on chromosome 3 (3p26.3->3p26.1) with the distal 5.7 Mb involving two parental haplotypes and the proximal 2.7 Mb involving three parental haplotypes, and a 6.1 Mb terminal mosaic deletion on chromosome 12 (12p13.33->12p13.31) with no evidence for a second haplotype. Adjacent to the mosaic deletion is an interstitial mosaic copy-neutral region of homozygosity (1.9 Mb, 12p13.31). The mother of this individual was confirmed by chromosome analysis and FISH that she carries a balanced translocation, t(3;12)(p26.1;p13.31). Conclusion Taken together, the proband, when at the stage of a zygote, likely carried the derivative chromosome 12 from this translocation, and a postzygotic mitotic recombination event occurred between the normal paternal chromosome 12 and maternal derivative chromosome 12 to “correct” the partial 3p trisomy and partial deletion of 12p. To the best of our knowledge, it is the first time to report the mechanism utilizing a combined cytogenetic and cytogenomic approach, and we believe it expands our knowledge of mosaic structural chromosomal disorders and provides new insight into clinical management and genetic counseling.
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Vibert R, Mignot C, Keren B, Chantot-Bastaraud S, Portnoï MF, Nouguès MC, Moutard ML, Faudet A, Whalen S, Haye D, Garel C, Chatron N, Rossi M, Vincent-Delorme C, Boute O, Delobel B, Andrieux J, Devillard F, Coutton C, Puechberty J, Pebrel-Richard C, Colson C, Gerard M, Missirian C, Sigaudy S, Busa T, Doco-Fenzy M, Malan V, Rio M, Doray B, Sanlaville D, Siffroi JP, Héron D, Heide S. Neurodevelopmental phenotype in 36 new patients with 8p inverted duplication-deletion: Genotype-phenotype correlation for anomalies of the corpus callosum. Clin Genet 2021; 101:307-316. [PMID: 34866188 DOI: 10.1111/cge.14096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/26/2021] [Accepted: 12/02/2021] [Indexed: 11/26/2022]
Abstract
Inverted duplication deletion 8p [invdupdel(8p)] is a complex and rare chromosomal rearrangement that combines a distal deletion and an inverted interstitial duplication of the short arm of chromosome 8. Carrier patients usually have developmental delay and intellectual disability (ID), associated with various cerebral and extra-cerebral malformations. Invdupdel(8p) is the most common recurrent chromosomal rearrangement in ID patients with anomalies of the corpus callosum (AnCC). Only a minority of invdupdel(8p) cases reported in the literature to date had both brain cerebral imaging and chromosomal microarray (CMA) with precise breakpoints of the rearrangements, making genotype-phenotype correlation studies for AnCC difficult. In this study, we report the clinical, radiological, and molecular data from 36 new invdupdel(8p) cases including three fetuses and five individuals from the same family, with breakpoints characterized by CMA. Among those, 97% (n = 32/33) of patients presented with mild to severe developmental delay/ID and 34% had seizures with mean age of onset of 3.9 years (2 months-9 years). Moreover, out of the 24 patients with brain MRI and 3 fetuses with neuropathology analysis, 63% (n = 17/27) had AnCC. We review additional data from 99 previously published patients with invdupdel(8p) and compare data of 17 patients from the literature with both CMA analysis and brain imaging to refine genotype-phenotype correlations for AnCC. This led us to refine a region of 5.1 Mb common to duplications of patients with AnCC and discuss potential candidate genes within this region.
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Affiliation(s)
- Roseline Vibert
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
| | - Cyril Mignot
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
| | - Boris Keren
- UF de Génomique du Développement, Département de Génétique, Groupe Hospitalier Pitié-Salpêtrière, APHP-Sorbonne Université, Paris, France
| | | | - Marie-France Portnoï
- Department of Cytogenetics, Armand Trousseau Hospital, APHP-Sorbonne Université, Paris, France
| | - Marie-Christine Nouguès
- Service of Pediatric Neurology, Armand Trousseau Hospital, APHP-Sorbonne Université, Paris, France
| | - Marie-Laure Moutard
- Service of Pediatric Neurology, Armand Trousseau Hospital, APHP-Sorbonne Université, Paris, France
| | - Anne Faudet
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
| | - Sandra Whalen
- UF de Génétique Clinique et Centre de Référence Maladies Rares des Anomalies du Développement et Syndromes Malformatifs, Hôpital Armand Trousseau, ERN ITHACA, APHP-Sorbonne Université, Paris, France
| | - Damien Haye
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
| | - Catherine Garel
- Department of Radiology, Armand Trousseau Hospital, APHP-Sorbonne Université, Paris, France
| | - Nicolas Chatron
- Departments of Genetics, Lyon University Hospitals, Lyon, France
| | - Massimiliano Rossi
- Genetics Department, Referral Centre for Developmental Abnormalities, Lyon University Hospital, and INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Centre, GENDEV Team, Claude Bernard Lyon 1 University, Bron, France
| | | | - Odile Boute
- Service of Clinical Genetic, Jeanne de Flandre Hospital, Lille, France
| | - Bruno Delobel
- Service of Cytogenetics, Institut Catholique de Lille, Lille, France
| | - Joris Andrieux
- Institute of Medical Genetics, Jeanne de Flandre Hospital, Lille, France
| | - Françoise Devillard
- Service de Génétique, Génomique, et Procréation, Centre Hospitalier Universitaire Grenoble Alpes, 38700 La Tronche, France; INSERM 1209, CNRS UMR 5309, Institute for Advanced Biosciences, Université Grenoble Alpes, Grenoble, France
| | - Charles Coutton
- Service de Génétique, Génomique, et Procréation, Centre Hospitalier Universitaire Grenoble Alpes, 38700 La Tronche, France; INSERM 1209, CNRS UMR 5309, Institute for Advanced Biosciences, Université Grenoble Alpes, Grenoble, France
| | - Jacques Puechberty
- Department of Medical Genetics, Arnaud de Villeneuve Hospital, Montpellier, France
| | - Céline Pebrel-Richard
- Service of Cytogenetic, Clermont-Ferrand's University Hospital, Clermont-Ferrand, France
| | - Cindy Colson
- Service of Clinical Genetic, Caen's University Hospital, Caen, France
| | - Marion Gerard
- Service of Clinical Genetic, Caen's University Hospital, Caen, France
| | - Chantal Missirian
- APHM, Laboratory of Genetic, Timone Enfants' Hospital, Marseille, France
| | - Sabine Sigaudy
- Department of Medical Genetics, Timone Enfants' Hospital, Marseille, France
| | - Tiffany Busa
- Department of Medical Genetics, Timone Enfants' Hospital, Marseille, France
| | | | - Valérie Malan
- APHP, Service de Médecine Génomique, Hôpital Necker-Enfants Malades, Paris, Université de Paris, Paris, France
| | - Marlène Rio
- Department of Genetics, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
| | - Bérénice Doray
- Service of Genetic, Felix Guyon Hospital, La Réunion, France
| | | | - Jean-Pierre Siffroi
- Department of Cytogenetics, Armand Trousseau Hospital, APHP-Sorbonne Université, Paris, France
| | - Delphine Héron
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
| | - Solveig Heide
- Département de Génétique, Hôpital Armand-Trousseau and Groupe Hospitalier Pitié-Salpêtrière, Centre de Référence Déficiences Intellectuelles de Causes Rares, APHP-Sorbonne Université, Paris, France
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46,XY,r(8)/45,XY,-8 Mosaicism as a Possible Mechanism of the Imprinted Birk-Barel Syndrome: A Case Study. Genes (Basel) 2020; 11:genes11121473. [PMID: 33316910 PMCID: PMC7763634 DOI: 10.3390/genes11121473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 11/25/2020] [Accepted: 12/07/2020] [Indexed: 12/27/2022] Open
Abstract
Ring chromosome 8 (r(8)) is one of the least frequent ring chromosomes. Usually, maternal chromosome 8 forms a ring, which can be lost from cells due to mitotic instability. The 8q24 region contains the imprinted KCNK9 gene, which is expressed from the maternal allele. Heterozygous KCNK9 mutations are associated with the imprinting disorder Birk-Barel syndrome. Here, we report a 2.5-year-old boy with developmental delay, microcephaly, dysmorphic features, diffuse muscle hypotonia, feeding problems, motor alalia and noncoarse neurogenic type of disturbance of muscle electrogenesis, partially overlapping with Birk-Barel syndrome phenotype. Cytogenetic analysis of lymphocytes revealed his karyotype to be 46,XY,r(8)(p23q24.3)[27]/45,XY,−8[3]. A de novo 7.9 Mb terminal 8p23.3p23.1 deletion, a 27.1 Mb 8p23.1p11.22 duplication, and a 4.4 Mb intact segment with a normal copy number located between them, as well as a 154-kb maternal LINGO2 gene deletion (9p21.2) with unknown clinical significance were identified by aCGH + SNP array. These aberrations were confirmed by real-time PCR. According to FISH analysis, the 8p23.1-p11.22 duplication was inverted. The ring chromosome originated from maternal chromosome 8. Targeted massive parallel sequencing did not reveal the KCNK9 mutations associated with Birk-Barel syndrome. Our data allow to assume that autosomal monosomy with inactive allele of imprinted gene arising from the loss of a ring chromosome in some somatic cells may be an etiological mechanism of mosaic imprinting disorders, presumably with less severe phenotype.
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Mohan S, Koshy T, Vekatachalam P, Nampoothiri S, Yesodharan D, Gowrishankar K, Kumar J, Ravichandran L, Joseph S, Chandrasekaran A, Paul SFD. Subtelomeric rearrangements in Indian children with idiopathic intellectual disability/developmental delay: Frequency estimation & clinical correlation using fluorescence in situ hybridization (FISH). Indian J Med Res 2017; 144:206-214. [PMID: 27934799 PMCID: PMC5206871 DOI: 10.4103/0971-5916.195031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022] Open
Abstract
Background & objectives: Subtelomeres are prone to deleterious rearrangements owing to their proximity to unique sequences on the one end and telomeric repetitive sequences, which increase their tendency to recombine, on the other end. These subtelomeric rearrangements resulting in segmental aneusomy are reported to contribute to the aetiology of idiopathic intellectual disability/developmental delay (ID/DD). We undertook this study to estimate the frequency of subtelomeric rearrangements in children with ID/DD. Methods: One hundred and twenty seven children with idiopathic ID/DD were tested for subtelomeric rearrangements using karyotyping and FISH. Blood samples were cultured, harvested, fixed and GTG-banded using the standard protocols. Results: Rearrangements involving the subtelomeres were observed in 7.8 per cent of the tested samples. Detection of rearrangements visible at the resolution of the karyotype constituted 2.3 per cent, while those rearrangements detected only with FISH constituted 5.5 per cent. Five deletions and five unbalanced translocations were detected. Analysis of parental samples wherever possible was informative regarding the inheritance of the rearrangement. Interpretation & conclusions: The frequency of subtelomeric rearrangements observed in this study was within the reported range of 0-35 per cent. All abnormal genotypes were clinically correlated. Further analysis with array technologies presents a future prospect. Our results suggest the need to test individuals with ID/DD for subtelomeric rearrangements using sensitive methods such as FISH.
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Affiliation(s)
- Shruthi Mohan
- Department of Human Genetics, Sri Ramachandra University, Porur, India
| | - Teena Koshy
- Department of Human Genetics, Sri Ramachandra University, Porur, India
| | | | - Sheela Nampoothiri
- Department of Paediatric Genetics, Amrita Institute of Medical Sciences, Kochi, India
| | - Dhanya Yesodharan
- Department of Paediatric Genetics, Amrita Institute of Medical Sciences, Kochi, India
| | - Kalpana Gowrishankar
- Department of Medical Genetics, CHILDS Trust Medical Research Foundation, Kanchi Kamakoti CHILDS Trust Hospital, Chennai, India
| | - Jeevan Kumar
- Department of Medical Genetics, CHILDS Trust Medical Research Foundation, Kanchi Kamakoti CHILDS Trust Hospital, Chennai, India
| | | | - Santhosh Joseph
- Department of Radiology, Sri Ramachandra University, Porur, India
| | | | - Solomon F D Paul
- Department of Human Genetics, Sri Ramachandra University, Porur, India
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