1
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Verbesselt J, Zink I, Breckpot J, Swillen A. Cross-sectional and longitudinal findings in patients with proximal 22q11.2 duplication: A retrospective chart study. Am J Med Genet A 2022; 188:46-57. [PMID: 34491614 PMCID: PMC8830490 DOI: 10.1002/ajmg.a.62487] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/05/2021] [Accepted: 08/10/2021] [Indexed: 01/03/2023]
Abstract
Duplications on Chromosome 22q11.2 (22q11.2 dup) are associated with a wide spectrum of physical and neurodevelopmental features. In this chart review, physical, developmental, and behavioral features of 28 patients with 22q11.2 dup (median age = 17.11 years) are reported, and phenotypes of de novo and inherited duplications are compared. Common medical anomalies include nutritional problems (57%), failure to thrive (33%), transient hearing impairment (52%), and congenital heart defects (33%). Developmental, speech-language, and motor delay are common in infancy, while attention (64%), learning (60%), and motor problems (52%) are typically reported at primary school age. Attention-deficit/hyperactivity disorders are diagnosed in 44%. Median full-scale intelligence quotient is in the borderline range (IQ 76), with one-fifth of patients having mild intellectual disability. Longitudinal data in 11 patients, with the first assessment at a median age of 5.2 years and the second assessment at a median age of 8.8 years, indicate that almost two-third of patients have a relative stable cognitive trajectory, whereas one-third show a growing into deficit profile. In patients with de novo duplications, there is a trend of more failure to thrive, while more patients with inherited duplications follow special education.
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Affiliation(s)
- Jente Verbesselt
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium
| | - Inge Zink
- Department of Neurosciences, Research Group Experimental Oto-Rhino-Laryngology (ExpORL), Leuven, Belgium,Department of Oto-Rhino-Laryngology, Head and Neck Surgery, MUCLA, University Hospitals Leuven, Leuven, Belgium
| | - Jeroen Breckpot
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium,Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Ann Swillen
- Department of Human Genetics, Catholic University Leuven, Leuven, Belgium,Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
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2
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Atli EI, Atli E, Yalcintepe S, Demir S, Mail C, Eker D, Ozen Y, Gurkan H. Clinical Features of Aberrations Chromosome 22q: A Pilot Study. Glob Med Genet 2021; 9:42-50. [PMID: 35169783 PMCID: PMC8837404 DOI: 10.1055/s-0041-1739496] [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: 09/10/2021] [Accepted: 09/29/2021] [Indexed: 11/12/2022] Open
Abstract
Objective
A significant number of genetic variations have been identified in chromosome 22, using molecular genetic techniques. Various genomic disorders on chromosome 22, including cat's eye syndrome caused by extra copies of the proximal region of the 22q chromosome, are now well-defined. Our aim in the study was to show phenotypic variability associated with rearrangements of the 22q chromosomal region.
Methods
We focused our study on clinical aspects of these disorders, including genetic testing, genotype-phenotype correlation, and potential treatments. A total of 998 patients were referred for genetic analysis (Karyotyping, MLPA, array-CGH) during January 2015 to February 2020 because of intellectual deficiency, behavior issues, and/or multiple congenital abnormalities in several genetics departments. Informed consent was obtained from all the patients and/or their parents.
Results
22q11.21 or 22q13.33 microdeletions and 22q11.22-q11.23 microduplication were identified in 31 patients out of referrals. The 22q aberrations were detected in 31/998 patients, giving a prevalence of 3.1%. In this study, 18 patients with 22q11.2 (LCR22A-H) deletion, three patients with 22q13.31 deletion, 9 patients with 22q11.2 duplication and one patient with 22q13.31 duplication were identified. We report on the clinical and molecular characterization of 31 individuals with distal deletions and duplications of chromosome 22q.
Conclusions
The current study demonstrated in the largest postnatal case series reporting the whole spectrum of atypical phenotypic and genotypic variations at 22q. We believe that when all the phenotypic differences are taken into account, various anomalies including developmental delay and intellectual disability might be considered as an indication to search for aberrations of 22q along with congenital heart diseases.
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Affiliation(s)
- Emine Ikbal Atli
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Engin Atli
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Sinem Yalcintepe
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Selma Demir
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Cisem Mail
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Damla Eker
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Yasemin Ozen
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
| | - Hakan Gurkan
- Department of Medical Genetics, Faculty of Medicine, Trakya University, Edirne, Turkey
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Spatiotemporal 22q11.21 Protein Network Implicates DGCR8-Dependent MicroRNA Biogenesis as a Risk for Late-Fetal Cortical Development in Psychiatric Diseases. Life (Basel) 2021; 11:life11060514. [PMID: 34073122 PMCID: PMC8227527 DOI: 10.3390/life11060514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 12/28/2022] Open
Abstract
The chromosome 22q11.21 copy number variant (CNV) is a vital risk factor that can be a genetic predisposition to neurodevelopmental disorders (NDD). As the 22q11.21 CNV affects multiple genes, causal disease genes and mechanisms affected are still poorly understood. Thus, we aimed to identify the most impactful 22q11.21 CNV genes and the potential impacted human brain regions, developmental stages and signaling pathways. We constructed the spatiotemporal dynamic networks of 22q11.21 CNV genes using the brain developmental transcriptome and physical protein–protein interactions. The affected brain regions, developmental stages, driver genes and pathways were subsequently investigated via integrated bioinformatics analysis. As a result, we first identified that 22q11.21 CNV genes affect the cortical area mainly during late fetal periods. Interestingly, we observed that connections between a driver gene, DGCR8, and its interacting partners, MECP2 and CUL3, also network hubs, only existed in the network of the late fetal period within the cortical region, suggesting their functional specificity during brain development. We also confirmed the physical interaction result between DGCR8 and CUL3 by liquid chromatography-tandem mass spectrometry. In conclusion, our results could suggest that the disruption of DGCR8-dependent microRNA biogenesis plays a vital role in NDD for late fetal cortical development.
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4
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Fischer M, Klopocki E. Atypical 22q11.2 Microduplication with "Typical" Signs and Overgrowth. Cytogenet Genome Res 2021; 160:659-663. [PMID: 33472199 PMCID: PMC8117256 DOI: 10.1159/000512486] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 10/21/2020] [Indexed: 11/19/2022] Open
Abstract
The 22q11.2 microduplication syndrome shows variable phenotypes with reduced penetrance compared to the 22q11.2 deletion syndrome. We report a woman with overgrowth and macrocephaly, mild mental retardation, heart defect, kidney anomalies, and dysmorphic features. Array-CGH analysis revealed a 246-kb duplication at the 22q11.2 region. No additional clinically significant CNVs were found. The case resembles a previously published case also showing overgrowth and macrocephaly with an almost identical 22q11.2 duplication of 252 kb.
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Affiliation(s)
- Matthias Fischer
- Department for Psychiatry and Psychotherapy, University of Rostock, Rostock, Germany,
- Department for Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany,
| | - Eva Klopocki
- Institute of Human Genetics, Biocenter, University of Würzburg, Würzburg, Germany
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5
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Niclass T, Le Guyader G, Beneteau C, Joubert M, Pizzuti A, Giuffrida MG, Bernardini L, Gilbert-Dussardier B, Bilan F, Egloff M. 12q21 deletion syndrome: Narrowing the critical region down to 1.6 Mb including SYT1 and PPP1R12A. Am J Med Genet A 2020; 182:2133-2138. [PMID: 32633079 DOI: 10.1002/ajmg.a.61734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/04/2020] [Accepted: 05/21/2020] [Indexed: 11/12/2022]
Abstract
Deletions in the 12q21 region are rare and non-recurrent CNVs. To date, only 11 patients with deletions in this region have been reported in the literature. These patients most often presented with syndromic intellectual deficiency, ventriculomegaly or hydrocephalus, ectodermal abnormalities, growth retardation and renal and cardiac malformations, suggesting a recognizable microdeletion syndrome. We report three new patients with overlapping deletions of the 12q21 region, including the smallest deletion reported to date and the first case characterized by array CGH during pregnancy. We describe specific clinical findings and shared facial features as developmental delay, ectodermal abnormalities, ventriculomegaly or hydrocephalus, axial hypotonia or spastic diplegia, growth retardation, heart defect, hydronephrosis, ureteral reflux or horseshoe kidney, large thorax or pectus excavatum, syndactyly of 2-3 toes, pterygium coli or excess nuchal skin, large anterior fontanel, low set ears, prominent forehead, short-upturned nose with nostril hypoplasia, microretrognathia and hypertelorism. These new patients and a comprehensive review of the literature allow us to define a minimum critical region spanning 1.6 Mb in 12q21. By screening the critical region using prediction tools, we identified two candidate genes: SYT1and PPP1R12A.
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Affiliation(s)
- Tanguy Niclass
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers, France
| | - Gwenael Le Guyader
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers, France.,EA 3808 NEUVACOD, Université de Poitiers, Poitiers, France
| | - Claire Beneteau
- Department of Medical Genetics, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Madeleine Joubert
- Department of Anatomic and Fetal Pathology, Centre Hospitalier Universitaire de Nantes, Nantes, France
| | - Antonio Pizzuti
- Department of Medical Genetics, Policlinico di Roma, Rome, Italy
| | - Maria Grazia Giuffrida
- Fondazione IRCCS Casa Sollievo della Sofferenza, Cytogenetics Unit, San Giovanni Rotondo, FG, Italy
| | - Laura Bernardini
- Fondazione IRCCS Casa Sollievo della Sofferenza, Cytogenetics Unit, San Giovanni Rotondo, FG, Italy
| | - Brigitte Gilbert-Dussardier
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers, France.,EA 3808 NEUVACOD, Université de Poitiers, Poitiers, France
| | - Frederic Bilan
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers, France.,EA 3808 NEUVACOD, Université de Poitiers, Poitiers, France
| | - Matthieu Egloff
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers, France.,Laboratoire de Neurosciences Experimentales et Cliniques, INSERM, Poitiers, France
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6
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Muys J, Jacquemyn Y, Blaumeiser B, Bourlard L, Brison N, Bulk S, Chiarappa P, De Leener A, De Rademaeker M, Désir J, Destrée A, Devriendt K, Dheedene A, Duquenne A, Fieuw A, Fransen E, Gatot J, Jamar M, Janssens S, Kerstjens J, Keymolen K, Lederer D, Menten B, Pichon B, Rombout S, Sznajer Y, Van Den Bogaert A, Van Den Bogaert K, Vermeesch J, Janssens K. Prenatally detected copy number variants in a national cohort: A postnatal follow‐up study. Prenat Diagn 2020; 40:1272-1283. [DOI: 10.1002/pd.5751] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 05/13/2020] [Accepted: 05/16/2020] [Indexed: 01/17/2023]
Affiliation(s)
- Joke Muys
- Department of Gynaecology University Hospital Antwerp Edegem Belgium
- Center for Medical Genetics, Universiteit Antwerpen Antwerpen Belgium
| | - Yves Jacquemyn
- Department of Gynaecology University Hospital Antwerp Edegem Belgium
- ASTARC and Global Health Institute Universiteit Antwerpen Antwerpen Belgium
| | - Bettina Blaumeiser
- Department of Gynaecology University Hospital Antwerp Edegem Belgium
- Center for Medical Genetics, Universiteit Antwerpen Antwerpen Belgium
| | - Laura Bourlard
- Center for Medical Genetics Université Libre de Bruxelles Bruxelles Belgium
| | - Nathalie Brison
- Center for Medical Genetics Katholieke Universiteit Leuven Leuven Belgium
| | - Saskia Bulk
- Center for Medical Genetics Centre Hospitalier Universitaire de Liège Liege Belgium
| | - Patrizia Chiarappa
- Center for Medical Genetics Université Catholique de Louvain Louvain‐la‐Neuve Belgium
| | - Anne De Leener
- Center for Medical Genetics Université Catholique de Louvain Louvain‐la‐Neuve Belgium
| | | | - Julie Désir
- Center for Medical Genetics Université Libre de Bruxelles Bruxelles Belgium
| | - Anne Destrée
- Center for Medical Genetics Institut de Pathologie et de Génétique Gosselies Gosselies Belgium
| | - Koenraad Devriendt
- Center for Medical Genetics Katholieke Universiteit Leuven Leuven Belgium
| | | | - Armelle Duquenne
- Center for Medical Genetics Université Catholique de Louvain Louvain‐la‐Neuve Belgium
| | - Annelies Fieuw
- Center for Medical Genetics Vrije Universiteit Brussel Brussel Belgium
| | - Erik Fransen
- Center for Medical Genetics, Universiteit Antwerpen Antwerpen Belgium
| | - Jean‐Stéphane Gatot
- Center for Medical Genetics Centre Hospitalier Universitaire de Liège Liege Belgium
| | - Mauricette Jamar
- Center for Medical Genetics Centre Hospitalier Universitaire de Liège Liege Belgium
| | | | - Jorien Kerstjens
- Faculty for Medical Sciences Rijksuniversteit Groningen Groningen The Netherlands
| | | | - Damien Lederer
- Center for Medical Genetics Institut de Pathologie et de Génétique Gosselies Gosselies Belgium
| | - Björn Menten
- Center for Medical Genetics Universiteit Gent Gent Belgium
| | - Bruno Pichon
- Center for Medical Genetics Université Libre de Bruxelles Bruxelles Belgium
| | - Sonia Rombout
- Center for Medical Genetics Institut de Pathologie et de Génétique Gosselies Gosselies Belgium
| | - Yves Sznajer
- Center for Medical Genetics Université Catholique de Louvain Louvain‐la‐Neuve Belgium
| | | | | | - Joris Vermeesch
- Center for Medical Genetics Katholieke Universiteit Leuven Leuven Belgium
| | - Katrien Janssens
- Center for Medical Genetics, Universiteit Antwerpen Antwerpen Belgium
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7
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Yu A, Turbiville D, Xu F, Ray JW, Britt AD, Lupo PJ, Jain SK, Shattuck KE, Robinson SS, Dong J. Genotypic and phenotypic variability of 22q11.2 microduplications: An institutional experience. Am J Med Genet A 2019; 179:2178-2189. [PMID: 31479204 DOI: 10.1002/ajmg.a.61345] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 07/05/2019] [Accepted: 08/12/2019] [Indexed: 12/26/2022]
Abstract
Duplications in the 22q11.2 region can cause 22q11.2 duplication syndrome and encompass a variety of phenotypes including developmental delays, facial abnormalities, cardiovascular defects, central nervous system delays, and other congenital abnormalities. However, the contribution of these contiguous duplicated regions to the clinical phenotypes has not been fully elucidated. In this study, we identified nine patients carrying different 22q11.2 microduplications detected by chromosomal microarray. Of these patients, seven pediatric patients presented with various clinical features including two neonate cases died shortly after birth, and two healthy adults. We examined region specific genotype-phenotype associations and found unpredictability associated with 22q11.2 duplications in these nine patients.
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Affiliation(s)
- Alexander Yu
- School of Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Donald Turbiville
- School of Medicine, University of Texas Medical Branch, Galveston, Texas
| | - Fangling Xu
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas
| | - Joseph W Ray
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Allison D Britt
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Pamela J Lupo
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Sunil K Jain
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Karen E Shattuck
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Sally S Robinson
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas
| | - Jianli Dong
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas
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8
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Li S, Han X, Ye M, Chen S, Shen Y, Niu J, Wang Y, Xu C. Prenatal Diagnosis of Microdeletions or Microduplications in the Proximal, Central, and Distal Regions of Chromosome 22q11.2: Ultrasound Findings and Pregnancy Outcome. Front Genet 2019; 10:813. [PMID: 31543904 PMCID: PMC6728414 DOI: 10.3389/fgene.2019.00813] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/06/2019] [Indexed: 12/11/2022] Open
Abstract
Several recurrent microdeletions and microduplications in the proximal, central, and distal regions of chromosomal 22q11.2 have been identified. However, due to a limited number of patients reported in the literature, highly variable clinical phenotypes, and incomplete penetrance, the pathogenicity of some microdeletions/microduplications in 22q11.2 central and distal regions is unclear. Hence, the genetic counseling and subsequent pregnancy decision are extremely challenging, especially when they are found in structurally normal fetuses. Here, we reported 27 consecutive cases diagnosed prenatally with 22q11.2 microdeletions or microduplications by chromosomal microarray analysis in our center. The prenatal ultrasound features, inheritance of the microdeletions/microduplications, and their effects on the pregnancy outcome were studied. We found that fetuses with 22q11.2 microdeletions were more likely to present with structure defects in the ultrasound, as compared with fetuses with 22q11.2 microduplications. Both the prenatal ultrasound findings and the inheritance of the microdeletions/microduplications affected the parent's decision of pregnancy. Those with structure defects in prenatal ultrasound or occurred de novo often resulted in termination of the pregnancy, whereas those with normal ultrasound and inherited from healthy parent were likely to continue the pregnancy and led to normal birth. Our study emphasized that proximal, central, and distal 22q11.2 deletions or duplications were different from each other, although some common features were shared among them. More studies are warranted to demonstrate the underlying mechanisms of different clinical features of these recurrent copy-number variations, thereby to provide more information for genetic counseling of 22q11.2 microdeletions and microduplications when they are detected prenatally.
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Affiliation(s)
- Shuyuan Li
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Han
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Mujin Ye
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Songchang Chen
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yinghua Shen
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Jianmei Niu
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yanlin Wang
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chenming Xu
- International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- Shanghai Key Laboratory of Embryo Original Diseases, Shanghai, China
- Institute of Embryo-Fetal Original Adult Disease, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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9
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Integrated FISH, Karyotyping and aCGH Analyses for Effective Prenatal Diagnosis of Common Aneuploidies and Other Cytogenomic Abnormalities. Med Sci (Basel) 2019; 7:medsci7020016. [PMID: 30678103 PMCID: PMC6410168 DOI: 10.3390/medsci7020016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/10/2019] [Accepted: 01/21/2019] [Indexed: 01/18/2023] Open
Abstract
Current prenatal genetic evaluation showed a significantly increase in non-invasive screening and the reduction of invasive diagnostic procedures. To evaluate the diagnostic efficacy on detecting common aneuploidies, structural chromosomal rearrangements, and pathogenic copy number variants (pCNV), we performed a retrospective analysis on a case series initially analyzed by aneuvysion fluorescence in situ hybridization (FISH) and karyotyping then followed by array comparative genomic hybridization (aCGH). Of the 386 cases retrieved from the past decade, common aneuploidies were detected in 137 cases (35.5%), other chromosomal structural rearrangements were detected in four cases (1%), and pCNV were detected in five cases (1.3%). The relative frequencies for common aneuploidies suggested an under detection of sex chromosome aneuploidies. Approximately 9.5% of cases with common aneuploidies showed a mosaic pattern. Inconsistent results between FISH and karyotyping were noted in cases with pseudo-mosaicism introduced by culture artifact or variable cellular proliferation from cells with mosaic karyotypic complements under in vitro cell culture. Based on findings from this case series, cell-based FISH and karyotyping should be performed to detect common aneuploidies, structural chromosomal abnormalities, and mosaic pattern. DNA-based aCGH and reflex FISH should be performed to detect and confirm genomic imbalances and pCNV. Practice points to ensure the diagnostic accuracy and efficacy were summarized.
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10
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Lacey CJ, Doudney K, Bridgman PG, George PM, Mulder RT, Zarifeh JJ, Kimber B, Cadzow MJ, Black MA, Merriman TR, Lehnert K, Bickley VM, Pearson JF, Cameron VA, Kennedy MA. Copy number variants implicate cardiac function and development pathways in earthquake-induced stress cardiomyopathy. Sci Rep 2018; 8:7548. [PMID: 29765130 PMCID: PMC5954162 DOI: 10.1038/s41598-018-25827-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 04/25/2018] [Indexed: 02/07/2023] Open
Abstract
The pathophysiology of stress cardiomyopathy (SCM), also known as takotsubo syndrome, is poorly understood. SCM usually occurs sporadically, often in association with a stressful event, but clusters of cases are reported after major natural disasters. There is some evidence that this is a familial condition. We have examined three possible models for an underlying genetic predisposition to SCM. Our primary study cohort consists of 28 women who suffered SCM as a result of two devastating earthquakes that struck the city of Christchurch, New Zealand, in 2010 and 2011. To seek possible underlying genetic factors we carried out exome analysis, genotyping array analysis, and array comparative genomic hybridization on these subjects. The most striking finding was the observation of a markedly elevated rate of rare, heterogeneous copy number variants (CNV) of uncertain clinical significance (in 12/28 subjects). Several of these CNVs impacted on genes of cardiac relevance including RBFOX1, GPC5, KCNRG, CHODL, and GPBP1L1. There is no physical overlap between the CNVs, and the genes they impact do not appear to be functionally related. The recognition that SCM predisposition may be associated with a high rate of rare CNVs offers a novel perspective on this enigmatic condition.
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Affiliation(s)
- Cameron J Lacey
- Department of Psychological Medicine, University of Otago, Christchurch, New Zealand.
| | - Kit Doudney
- Molecular Pathology Laboratory, Canterbury Health Laboratories, Canterbury District Health Board, Christchurch, New Zealand
| | - Paul G Bridgman
- Department of Cardiology, Christchurch Hospital, Christchurch, New Zealand
| | - Peter M George
- Molecular Pathology Laboratory, Canterbury Health Laboratories, Canterbury District Health Board, Christchurch, New Zealand
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand
| | - Roger T Mulder
- Department of Psychological Medicine, University of Otago, Christchurch, New Zealand
| | - Julie J Zarifeh
- Psychiatric Consultation Service, Christchurch Hospital, Canterbury District Health Board, Christchurch, New Zealand
| | - Bridget Kimber
- Department of Psychological Medicine, University of Otago, Christchurch, New Zealand
| | - Murray J Cadzow
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Michael A Black
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Tony R Merriman
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | - Klaus Lehnert
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Vivienne M Bickley
- Molecular Pathology Laboratory, Canterbury Health Laboratories, Canterbury District Health Board, Christchurch, New Zealand
| | - John F Pearson
- Biostatistics and Computational Biology Unit, University of Otago, Christchurch, New Zealand
| | - Vicky A Cameron
- Christchurch Heart Institute, Department of Medicine, University of Otago, Christchurch, New Zealand
| | - Martin A Kennedy
- Department of Pathology and Biomedical Science, University of Otago, Christchurch, New Zealand.
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11
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Brabbing-Goldstein D, Reches A, Svirsky R, Bar-Shira A, Yaron Y. Dilemmas in genetic counseling for low-penetrance neuro-susceptibility loci detected on prenatal chromosomal microarray analysis. Am J Obstet Gynecol 2018; 218:247.e1-247.e12. [PMID: 29146387 DOI: 10.1016/j.ajog.2017.11.559] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 10/14/2017] [Accepted: 11/06/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND Chromosomal microarray analysis is standard of care in fetuses with malformations, detecting clinically significant copy number variants in 5-7% of cases over conventional karyotyping. However, it also detects variants of uncertain significance in 1.6-4.2% of the cases, some of which are low-penetrance neuro-susceptibility loci. The interpretation of these variants in pregnancy is particularly challenging because the significance is often unclear and the clinical implications may be difficult to predict. OBJECTIVE The purpose of this study was to describe counseling dilemmas regarding low-penetrance neuro-susceptibility loci that are detected by prenatal chromosomal microarray analysis. STUDY DESIGN During the study period (January 2014 to December 2015), 700 prenatal chromosomal microarray analyses were performed. Cases were categorized as "indicated" (n=375) if there were abnormal sonographic findings or suggestive medical history and "patient choice" (n=325) in the presence of a structurally normal fetus with no other particular indication. The laboratory reported on copy number variants ≥400 Kb in size in loci known to be associated with genetic syndromes and ≥1 Mb in other areas of genome. Results were classified as gross aneuploidy, copy number variants, and normal. Copy number variants were categorized according to the American College of Medical Genetics standards and guidelines: pathogenic, variants of uncertain significance, or benign. Variants of uncertain significance were further subdivided into categories of likely pathogenic, variants of uncertain significance with no subclassification, and likely benign. Statistical analysis was performed with the use of Chi square test and Fisher's exact test to compare intergroup differences in incidence of the different result categories and demographic data. RESULTS Patient choice cases became more prevalent with time (35.5% in the beginning of the study, compared with 48.4% at the end of the study period). Clinically significant copy number variants were found in 14 of 375 (3.7%) of indicated cases vs only 2 of 325 (0.6%) of patient choice cases (P=.009). All "likely benign" variants consisted of low-penetrance neuro-susceptibility loci. The incidence thereof was similar between the indicated and patient choice groups (3.7% vs 3.4%; P=.85). In the indicated group, some variants of uncertain significance may have contributed to the abnormal anatomic findings. Conversely, in the patient choice group, the finding of low-penetrance neuro-susceptibility loci was often unexpected and confounding for prospective parents. CONCLUSION Prenatal chromosomal microarray analysis added clinically significant information in both groups. However, it also detected low-penetrance neuro-susceptibility loci in approximately 3.5% of the cases. This fact should be conveyed during pretest counseling to allow patients to make informed choices, particularly when chromosomal microarray is to be performed for patient choice.
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12
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Pinchefsky E, Laneuville L, Srour M. Distal 22q11.2 Microduplication: Case Report and Review of the Literature. Child Neurol Open 2017; 4:2329048X17737651. [PMID: 29147671 PMCID: PMC5673001 DOI: 10.1177/2329048x17737651] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/24/2017] [Accepted: 08/19/2017] [Indexed: 12/20/2022] Open
Abstract
Distal chromosome 22q11.2 microduplications are associated with a wide range of phenotypes and unclear pathogenicity. The authors report on a 3-year-old girl with global developmental delay harboring a de novo 1.24 Mb distal chromosome 22q11.2 microduplication and a paternally inherited 0.25 Mb chromosome 4p14 microduplication. The authors review clinical features of 30 reported cases of distal 22q11.2 duplications. Common features include developmental delay (93%), neuropsychiatric features (26%), and nonspecific facial dysmorphisms (74%). In 70% of cases, the distal 22q11.2 duplications were inherited, and the majority of the carrier parents were phenotypically normal. Furthermore, 30% of probands carried an additional copy number variant. Review of the phenotype in individuals carrying microduplications involving similar low copy repeats (LCR) failed to establish any clear genotype–phenotype correlations. Distal 22q11.2 duplications represent a major challenge for genetic counseling and prediction of clinical consequences. Our report suggests a pathogenic role of distal 22q11.2 duplications and supports a “multiple hit” hypothesis underlying its variable expressivity and phenotypic severity.
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Affiliation(s)
- Elana Pinchefsky
- Division of Pediatric Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre (MUHC), Montreal, Québec, Canada
| | | | - Myriam Srour
- Division of Pediatric Neurology, Department of Pediatrics, Montreal Children's Hospital, McGill University Health Centre (MUHC), Montreal, Québec, Canada
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13
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Genotype and phenotype spectrum of NRAS germline variants. Eur J Hum Genet 2017; 25:823-831. [PMID: 28594414 DOI: 10.1038/ejhg.2017.65] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 03/14/2017] [Accepted: 03/28/2017] [Indexed: 12/20/2022] Open
Abstract
RASopathies comprise a group of disorders clinically characterized by short stature, heart defects, facial dysmorphism, and varying degrees of intellectual disability and cancer predisposition. They are caused by germline variants in genes encoding key components or modulators of the highly conserved RAS-MAPK signalling pathway that lead to dysregulation of cell signal transmission. Germline changes in the genes encoding members of the RAS subfamily of GTPases are rare and associated with variable phenotypes of the RASopathy spectrum, ranging from Costello syndrome (HRAS variants) to Noonan and Cardiofaciocutaneous syndromes (KRAS variants). A small number of RASopathy cases with disease-causing germline NRAS alterations have been reported. Affected individuals exhibited features fitting Noonan syndrome, and the observed germline variants differed from the typical oncogenic NRAS changes occurring as somatic events in tumours. Here we describe 19 new cases with RASopathy due to disease-causing variants in NRAS. Importantly, four of them harbored missense changes affecting Gly12, which was previously described to occur exclusively in cancer. The phenotype in our cohort was variable but well within the RASopathy spectrum. Further, one of the patients (c.35G>A; p.(Gly12Asp)) had a myeloproliferative disorder, and one subject (c.34G>C; p.(Gly12Arg)) exhibited an uncharacterized brain tumour. With this report, we expand the genotype and phenotype spectrum of RASopathy-associated germline NRAS variants and provide evidence that NRAS variants do not spare the cancer-associated mutation hotspots.
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14
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Lantieri F, Malacarne M, Gimelli S, Santamaria G, Coviello D, Ceccherini I. Custom Array Comparative Genomic Hybridization: the Importance of DNA Quality, an Expert Eye, and Variant Validation. Int J Mol Sci 2017; 18:E609. [PMID: 28287439 PMCID: PMC5372625 DOI: 10.3390/ijms18030609] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/01/2017] [Accepted: 03/07/2017] [Indexed: 12/16/2022] Open
Abstract
The presence of false positive and false negative results in the Array Comparative Genomic Hybridization (aCGH) design is poorly addressed in literature reports. We took advantage of a custom aCGH recently carried out to analyze its design performance, the use of several Agilent aberrations detection algorithms, and the presence of false results. Our study provides a confirmation that the high density design does not generate more noise than standard designs and, might reach a good resolution. We noticed a not negligible presence of false negative and false positive results in the imbalances call performed by the Agilent software. The Aberration Detection Method 2 (ADM-2) algorithm with a threshold of 6 performed quite well, and the array design proved to be reliable, provided that some additional filters are applied, such as considering only intervals with average absolute log₂ratio above 0.3. We also propose an additional filter that takes into account the proportion of probes with log₂ratio exceeding suggestive values for gain or loss. In addition, the quality of samples was confirmed to be a crucial parameter. Finally, this work raises the importance of evaluating the samples profiles by eye and the necessity of validating the imbalances detected.
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Affiliation(s)
- Francesca Lantieri
- Dipartimento di Scienzedella Salute, Sezione di Biostatistica, Università degli Studi di Genova, Via Pastore 1, 16132 Genoa, Italy.
| | - Michela Malacarne
- Struttura Complessa Laboratorio Genetica Umana, E.O. Ospedali Galliera, Via Volta 6, 16128 Genoa, Italy.
| | - Stefania Gimelli
- Department of Medical Genetic and Laboratories, University Hospitals of Geneva, Bâtiment de Base 8C-3-840.3, 4 Rue Gabrielle-Perret-Gentil, 1211 Geneva 14, Switzerland.
| | - Giuseppe Santamaria
- UOC Genetica Medica, Istituto Giannina Gaslini, L. go G. Gaslini 5, 16148 Genoa, Italy.
| | - Domenico Coviello
- Struttura Complessa Laboratorio Genetica Umana, E.O. Ospedali Galliera, Via Volta 6, 16128 Genoa, Italy.
| | - Isabella Ceccherini
- UOC Genetica Medica, Istituto Giannina Gaslini, L. go G. Gaslini 5, 16148 Genoa, Italy.
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15
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Sajan SA, Jhangiani SN, Muzny DM, Gibbs RA, Lupski JR, Glaze DG, Kaufmann WE, Skinner SA, Annese F, Friez MJ, Lane J, Percy AK, Neul JL. Enrichment of mutations in chromatin regulators in people with Rett syndrome lacking mutations in MECP2. Genet Med 2016; 19:13-19. [PMID: 27171548 PMCID: PMC5107176 DOI: 10.1038/gim.2016.42] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/24/2016] [Indexed: 02/08/2023] Open
Abstract
Purpose Rett Syndrome (RTT) is a neurodevelopmental disorder caused primarily by de novo mutations (DNMs) in MECP2 and sometimes in CDKL5 and FOXG1. However, some RTT cases lack mutations in these genes. Methods Twenty-two RTT cases without apparent MECP2, CDKL5, and FOXG1 mutations were subjected to both whole exome sequencing and single nucleotide polymorphism array-based copy number variant (CNV) analyses. Results Three cases had MECP2 mutations initially missed by clinical testing. Of the remaining 19 cases, 17 (89.5%) had 29 other likely pathogenic intragenic mutations and/or CNVs (10 cases had two or more). Interestingly, 13 cases had mutations in a gene/region previously reported in other NDDs, thereby providing a potential diagnostic yield of 68.4%. These mutations were significantly enriched in chromatin regulators (corrected p = 0.0068) and moderately in postsynaptic cell membrane molecules (corrected p = 0.076) implicating glutamate receptor signaling. Conclusion The genetic etiology of RTT without MECP2, CDKL5, and FOXG1 mutations is heterogeneous, overlaps with other NDDs, and complex due to high mutation burden. Dysregulation of chromatin structure and abnormal excitatory synaptic signaling may form two common pathological bases of RTT.
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Affiliation(s)
- Samin A Sajan
- Section of Child Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA.,Current address: Department of Neurosciences, University of California San Diego, San Diego, California, USA
| | - Shalini N Jhangiani
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - James R Lupski
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine and Texas Children's Hospital, Houston, Texas, USA
| | - Daniel G Glaze
- Section of Child Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Walter E Kaufmann
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Fran Annese
- Greenwood Genetic Center, Greenwood, South Carolina, USA
| | | | - Jane Lane
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Alan K Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey L Neul
- Section of Child Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Current address: Department of Neurosciences, University of California San Diego, San Diego, California, USA
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16
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The Identification of Microdeletion and Reciprocal Microduplication in 22q11.2 Using High-Resolution CMA Technology. BIOMED RESEARCH INTERNATIONAL 2016; 2016:7415438. [PMID: 27123452 PMCID: PMC4830712 DOI: 10.1155/2016/7415438] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 03/13/2016] [Indexed: 01/05/2023]
Abstract
The chromosome 22q11.2 region has long been implicated in genomic diseases. Some genomic regions exhibit numerous low copy repeats with high identity in which they provide increased genomic instability and mediate deletions and duplications in many disorders. DiGeorge Syndrome is the most common deletion syndrome and reciprocal duplications could be occurring in half of the frequency of microdeletions. We described five patients with phenotypic variability that carries deletions or reciprocal duplications at 22q11.2 detected by Chromosomal Microarray Analysis. The CytoScan HD technology was used to detect changes in the genome copy number variation of patients who had clinical indication to global developmental delay and a normal karyotype. We observed in our study three microdeletions and two microduplications in 22q11.2 region with variable intervals containing known genes and unstudied transcripts as well as the LCRs that are often flanking and within this genomic rearrangement. The identification of these variants is of particular interest because it may provide insight into genes or genomic regions that are crucial for specific phenotypic manifestations and are useful to assist in the quest for understanding the mechanisms subjacent to genomic deletions and duplications.
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17
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Identification of Proximal and Distal 22q11.2 Microduplications among Patients with Cleft Lip and/or Palate: A Novel Inherited Atypical 0.6 Mb Duplication. GENETICS RESEARCH INTERNATIONAL 2015; 2015:398063. [PMID: 26640714 PMCID: PMC4660028 DOI: 10.1155/2015/398063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 10/05/2015] [Accepted: 10/15/2015] [Indexed: 11/18/2022]
Abstract
Misalignments of low-copy repeats (LCRs) located in chromosome 22, particularly band 22q11.2, predispose to rearrangements. A variety of phenotypic features are associated with 22q11.2 microduplication syndrome which makes it challenging for the genetic counselors to recommend appropriate genetic assessment and counseling for the patients. In this study, multiplex ligation probe dependent amplification (MLPA) analysis was performed on 378 patients with cleft lip and/or palate to characterize rearrangements in patients suspected of 22q11.2 microduplication and microdeletion syndromes. Of 378 cases, 15 were diagnosed with a microdeletion with various sizes and 3 with duplications. For the first time in this study an atypical 0.6 Mb duplication is reported. Illustration of the phenotypes associated with the microduplications increases the knowledge of phenotypes reported in the literature.
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18
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Tan TY, Gordon CT, Miller KA, Amor DJ, Farlie PG. YPEL1
overexpression in early avian craniofacial mesenchyme causes mandibular dysmorphogenesis by up‐regulating apoptosis. Dev Dyn 2015; 244:1022-30. [DOI: 10.1002/dvdy.24299] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Revised: 05/24/2015] [Accepted: 05/26/2015] [Indexed: 11/10/2022] Open
Affiliation(s)
- Tiong Yang Tan
- Victorian Clinical Genetics Services, Royal Children's HospitalMelbourne Australia
- Murdoch Children's Research InstituteMelbourne Australia
- Department of PaediatricsUniversity of MelbourneMelbourne Australia
| | | | - Kerry A Miller
- Murdoch Children's Research InstituteMelbourne Australia
| | - David J. Amor
- Victorian Clinical Genetics Services, Royal Children's HospitalMelbourne Australia
- Murdoch Children's Research InstituteMelbourne Australia
- Department of PaediatricsUniversity of MelbourneMelbourne Australia
| | - Peter G. Farlie
- Murdoch Children's Research InstituteMelbourne Australia
- Department of PaediatricsUniversity of MelbourneMelbourne Australia
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19
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Chang J, Zhao L, Chen C, Peng Y, Xia Y, Tang G, Bai T, Zhang Y, Ma R, Guo R, Mei L, Liang D, Cao Q, Wu L. Pachygyria, seizures, hypotonia, and growth retardation in a patient with an atypical 1.33Mb inherited microduplication at 22q11.23. Gene 2015; 569:46-50. [PMID: 26099517 DOI: 10.1016/j.gene.2015.04.090] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2015] [Accepted: 04/09/2015] [Indexed: 12/11/2022]
Abstract
22q11.2 microduplication syndrome was recently described as a new disorder with variable clinical features that ranged from normal to mental retardation and with congenital defects. According to published reports, majority of patients with 22q11.2 duplications inherit these from unaffected parents rather than by de novo mutations, which is different from most microduplication/microdeletion syndromes. In this study, we report a patient that carried a paternally inherited atypical 1.33Mb duplication at 22q11.23. The proband (or proposita) presented with hypotonia, feeding difficulties, intractable epilepsy, hearing disability, and pachygyria. A pachygyria phenotype had not been previously reported to be associated with a 22q11 microduplication syndrome. Cytogenetic and molecular genetic analyses based on standard G-banding, SNP array, and fluorescence in situ hybridization were performed for the proband and her parents. An atypical 1.33Mb duplication at 22q11.23 was detected in both the proband and her father. Thus, our findings verify the pathogenicity and diverse phenotypes of 22q11.2 microduplication and expand its phenotypic spectrum.
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Affiliation(s)
- Jiazhen Chang
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Lijuan Zhao
- The Fourth Hospital of Shijiazhuang, Shijiazhuang, Hebei, P.R. China
| | - Chen Chen
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China; Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, Hunan, P.R. China
| | - Ying Peng
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Yan Xia
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Guizhi Tang
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Ting Bai
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Yanghui Zhang
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Ruiyu Ma
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Ruolan Guo
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Libin Mei
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Desheng Liang
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China
| | - Qinying Cao
- The Fourth Hospital of Shijiazhuang, Shijiazhuang, Hebei, P.R. China.
| | - Lingqian Wu
- State Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, P.R. China.
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20
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Lindgren V, McRae A, Dineen R, Saulsberry A, Hoganson G, Schrift M. Behavioral abnormalities are common and severe in patients with distal 22q11.2 microdeletions and microduplications. Mol Genet Genomic Med 2015; 3:346-53. [PMID: 26247050 PMCID: PMC4521969 DOI: 10.1002/mgg3.146] [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: 11/21/2014] [Revised: 03/11/2015] [Accepted: 03/16/2015] [Indexed: 11/13/2022] Open
Abstract
We describe six individuals with microdeletions and microduplications in the distal 22q11.2 region detected by microarray. Five of the abnormalities have breakpoints in the low-copy repeats (LCR) in this region and one patient has an atypical rearrangement. Two of the six patients with abnormalities in the region between LCR22 D–E have hearing loss, which has previously been reported only once in association with these abnormalities. We especially note the behavioral/neuropsychiatric problems, including the severity and early onset, in patients with distal 22q11.2 rearrangements. Our patients add to the genotype–phenotype correlations which are still being generated for these chromosomal anomalies.
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Affiliation(s)
- Valerie Lindgren
- Department of Pathology, University of Illinois Chicago, Illinois
| | - Anne McRae
- Department of Pediatrics, University of Illinois Chicago, Illinois
| | - Richard Dineen
- Department of Pediatrics, University of Illinois Chicago, Illinois
| | | | - George Hoganson
- Department of Pediatrics, University of Illinois Chicago, Illinois
| | - Michael Schrift
- Department of Psychiatry, University of Illinois Chicago, Illinois
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21
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Diehl A, Mu W, Batista D, Gunay-Aygun M. An atypical 0.73 MB microduplication of 22q11.21 and a novel SALL4 missense mutation associated with thumb agenesis and radioulnar synostosis. Am J Med Genet A 2015; 167:1644-9. [PMID: 25823593 DOI: 10.1002/ajmg.a.37066] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 03/06/2015] [Indexed: 01/14/2023]
Abstract
We describe a 0.73 Mb duplication of chromosome 22q11.21 between LCR-B and LCR-D and a missense mutation in a conserved C2H2 zinc finger domain of SALL4 in a cognitively normal patient with multiple skeletal anomalies including radioulnar synostosis, thumb aplasia, butterfly vertebrae, rib abnormalities, and hypoplasia of the humeral and femoral epiphyses. 22q11.21 is a common site for microdeletions and their reciprocal microduplications as a result of non-allelic homologous recombination between its multiple low copy repeat regions (LCR). DiGeorge /Velocardiofacial syndrome (DG/VCFS) is classically caused by a 3 Mb deletion between LCR-A and LCR-D or a 1.5 Mb deletion between LCR-A and LCR-B. The reciprocal syndrome to DG/VCFS is the recently described 22q11.2 microduplication, which usually presents with the typical 3 Mb or 1.5 Mb duplication. Numerous atypical deletions and duplications have been reported between other LCRs. Typically, SALL4-related Duane-radial ray syndrome is caused by deletions or nonsense mutations; the only missense SALL4 mutation described prior was thought to result in gain of function and produced cranial midline defects. The skeletal anomalies presented in this report have not been previously described in association with 22q11.2 microduplication nor SALL4 mutations.
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Affiliation(s)
- Adam Diehl
- School of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Weiyi Mu
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Denise Batista
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Cytogenetics and Microarray Laboratory, Kennedy Krieger Institute, Baltimore, Maryland.,Department of Pathology, Johns Hopkins University, Baltimore, Maryland
| | - Meral Gunay-Aygun
- Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.,Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland
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22
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Abstract
Mowat-Wilson syndrome is a recently delineated multiple congenital anomaly syndrome characterized by a distinctive facial appearance in association with intellectual disability, microcephaly, agenesis of the corpus callosum, seizures, congenital heart disease, Hirschsprung disease, short stature, and genitourinary anomalies. We report a 2-year-10-month-old white female with this syndrome caused by mutations in the ZEB2 gene, and in addition a duplication of the 22q11.23, a previously undocumented occurrence.
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Affiliation(s)
- Ersida Buraniqi
- Istanbul School of Medicine, Istanbul University, Istanbul, Turkey
| | - Manikum Moodley
- Center for Pediatric Neurology, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
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23
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Molck MC, Vieira TP, Simioni M, Sgardioli IC, Santos APD, Xavier AC, Gil-da-Silva-Lopes VL. Distal 22q11.2 microduplication combined with typical 22q11.2 proximal deletion: A case report. Am J Med Genet A 2014; 167A:215-20. [DOI: 10.1002/ajmg.a.36809] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 09/11/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Miriam Coelho Molck
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
| | - Társis Paiva Vieira
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
| | - Milena Simioni
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
| | - Ilária Cristina Sgardioli
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
| | - Ana Paula dos Santos
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
| | - Ana Carolina Xavier
- Center for Research and Rehabilitation of Lip and Palate Lesions (CRRLPL) Centrinho Prefeito Luiz Gomes; Joinville Santa Catarina Brazil
| | - Vera Lúcia Gil-da-Silva-Lopes
- Department of Medical Genetics; Faculty of Medical Sciences; University of Campinas (UNICAMP); Sao Paulo Brazil
- Assistance Center for Cleft Lip and Palate (CAIF); Curitiba Parana Brazil
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24
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Dupont C, Grati FR, Choy KW, Jaillard S, Toutain J, Maurin ML, Martínez-Conejero JA, Beneteau C, Coussement A, Molina-Gomes D, Horelli-Kuitunen N, Aboura A, Tabet AC, Besseau-Ayasse J, Bessieres-Grattagliano B, Simoni G, Ayala G, Benzacken B, Vialard F. Prenatal diagnosis of 24 cases of microduplication 22q11.2: an investigation of phenotype-genotype correlations. Prenat Diagn 2014; 35:35-43. [PMID: 25118001 DOI: 10.1002/pd.4478] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 07/29/2014] [Accepted: 08/06/2014] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Microduplication 22q11.2 is primarily characterized by a highly variable clinical phenotype, which ranges from apparently normal or slightly dysmorphic features (in the presence or absence of learning disorders) to severe malformations with profound mental retardation. Hence, genetic counseling is particularly challenging when microduplication 22q11.2 is identified in a prenatal diagnosis. Here, we report on 24 prenatal cases of microduplication 22q11.2. METHODS Seventeen of the cases were also reanalyzed by microarray analysis, in order to determine copy number variations (CNVs, which are thought to influence expressivity). We also searched for possible correlations between fetal phenotypes, indications for invasive prenatal diagnosis, inheritance, and pregnancy outcomes. RESULTS Of the 24 cases, 15 were inherited, six occurred de novo, and three were of unknown origin. Termination of pregnancy occurred in seven cases and was mainly decided on the basis of ultrasound findings. Moreover, additional CNVs were found in some patients and we try to make a genotype-phenotype correlation. CONCLUSION We discuss the complexity of genetic counseling for microduplication 22q11.2 and comment on possible explanations for the clinical heterogeneity of this syndrome. In particular, we assessed the co-existence of additional CNVs and their contribution to phenotypic variations in chromosome 22q11.2 microduplication syndrome.
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Affiliation(s)
- Céline Dupont
- Unité de Cytogénétique, Département de Génétique, Hôpital Robert Debré-AP-HP, CHU Paris, Paris, France
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25
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Abstract
Prenatal array comparative genome hybridisation (aCGH) testing has by and large replaced routine karyotyping in many healthcare settings. While this will lead to more diagnoses, uncertain, unexpected or unhelpful findings are also likely to increase. This is the case for aCGH in any setting, but we discuss the particular challenges the prenatal setting generates and suggest areas that need further debate and discussion as well as some pragmatic ways forward.
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Kim HJ, Jo HS, Yoo EG, Chung IH, Kim SW, Lee KH, Chang YH. 22q11.2 Microduplication with thyroid hemiagenesis. Horm Res Paediatr 2013; 79:243-9. [PMID: 23364243 DOI: 10.1159/000346411] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2012] [Accepted: 12/11/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Chromosome 22q11.2 microduplications are extremely rarely detected; in comparison, the deletion of same region, known as the DiGeorge/velocardiofacial syndrome, occurs more frequently. Thyroid anomalies commonly occur in patients with 22q11.2 deletion syndrome, however few reports of thyroid anomalies associated with 22q11.2 microduplication have been published thus far. CASE REPORT We present a case of a male infant who was prenatally diagnosed with 22q11.2 microduplication and was found to have congenital hypothyroidism due to thyroid hemiagenesis after birth. Moreover, the baby had bilateral hearing impairment, bilateral cryptorchidism, and a rotated penis. At the age of 2 years, the infant was euthyroid with levothyroxine replacement, but he showed significant developmental delay. CONCLUSIONS To our knowledge, this is the first case of congenital hypothyroidism with thyroid hemiagenesis in a patient showing 22q11.2 microduplication. Thyroid dysgenesis could be an additional clinical feature shared by the 22q11.2 microduplication and deletion syndrome, suggesting that the duplication and deletion of a gene may result in a common phenotype. Thyroid dysgenesis should be considered in the evaluation and management of patients with this genomic disorder.
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Affiliation(s)
- Hae Jung Kim
- Department of Pediatrics, CHA Bundang Medical Center, CHA University, Seongnam, Korea
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27
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Tarsitano M, Ceglia C, Novelli A, Capalbo A, Lombardo B, Pastore L, Fioretti G, Vicari L, Pisanti MA, Friso P, Cavaliere ML. Microduplications in 22q11.2 and 8q22.1 associated with mild mental retardation and generalized overgrowth. Gene 2013; 536:213-6. [PMID: 24315824 DOI: 10.1016/j.gene.2013.11.051] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2013] [Revised: 11/04/2013] [Accepted: 11/22/2013] [Indexed: 12/21/2022]
Abstract
The 22q11.2 microduplication is a genomic disorder, characterized from a variable phenotype ranging from different defects to normality. The most common microduplication of 22q11.2 is 3 Mb in size, but there are also cases reported with atypical duplications between 0.8 Mb and 6Mb. Here, we describe a case of a child with macrocephaly, overgrowth with advanced bone age, attention deficits, evidence of mild mental retardation and dysmorphic features. An array-CGH analysis detected a 252 Kb duplication at the 22q11.2 region inherited from mother and 142 Kb duplication at 8q22.1 region inherited from father. Both parents show mild dysmorphic features. The duplicated genes in chromosomes 22q and 8q are TOP3B and PGCP, respectively. We describe for the first time a patient carrying the smaller atypical 22q11.2 duplication who also presents with mild mental retardation and generalized overgrowth. This patient has an additional duplication in 8q22.1 which may act as a genomic modifier of its clinical phenotype.
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Affiliation(s)
| | - Carlo Ceglia
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy
| | - Antonio Novelli
- Mendel Laboratory, Casa Sollievo della Sofferenza IRCCS, Viale Regina Margherita 261, 00198 Rome, Italy
| | - Anna Capalbo
- Mendel Laboratory, Casa Sollievo della Sofferenza IRCCS, Viale Regina Margherita 261, 00198 Rome, Italy
| | - Barbara Lombardo
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy; Department Biochemistry and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Lucio Pastore
- CEINGE Advanced Biotechnology, S.c.a.r.l., Naples, Italy; Department Biochemistry and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | | | - Laura Vicari
- Service of Medical Genetics, Cardarelli Hospital, Naples, Italy
| | | | - Patrizia Friso
- Service of Medical Genetics, Cardarelli Hospital, Naples, Italy
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28
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Carey AS, Liang L, Edwards J, Brandt T, Mei H, Sharp AJ, Hsu DT, Newburger JW, Ohye RG, Chung WK, Russell MW, Rosenfeld JA, Shaffer LG, Parides MK, Edelmann L, Gelb BD. Effect of copy number variants on outcomes for infants with single ventricle heart defects. CIRCULATION. CARDIOVASCULAR GENETICS 2013; 6:444-51. [PMID: 24021551 PMCID: PMC3987966 DOI: 10.1161/circgenetics.113.000189] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND Human genomes harbor copy number variants (CNVs), which are regions of DNA gains or losses. Although pathogenic CNVs are associated with congenital heart disease (CHD), their effect on clinical outcomes is unknown. This study sought to determine whether pathogenic CNVs among infants with single ventricle physiology were associated with inferior neurocognitive and somatic growth outcomes. METHODS AND RESULTS Genomic DNAs from 223 subjects of 2 National Heart, Lung, and Blood Institute-sponsored randomized clinical trials in infants with single ventricle CHD and 270 controls from The Cancer Genome Atlas project were analyzed for rare CNVs>300 kb using array comparative genomic hybridization. Neurocognitive and growth outcomes at 14 months from the CHD trials were compared among subjects with and without pathogenic CNVs. Putatively pathogenic CNVs, comprising 25 duplications and 6 deletions, had a prevalence of 13.9%, significantly greater than the 4.4% rate of such CNVs among controls. CNVs associated with genomic disorders were found in 13 cases but not in controls. Several CNVs likely to be causative of single ventricle CHD were observed, including aberrations altering the dosage of GATA4, MYH11, and GJA5. Subjects with pathogenic CNVs had worse linear growth, and those with CNVs associated with known genomic disorders had the poorest neurocognitive and growth outcomes. A minority of children with pathogenic CNVs were noted to be dysmorphic on clinical genetics examination. CONCLUSIONS Pathogenic CNVs seem to contribute to the cause of single ventricle forms of CHD in ≥10% of cases and are clinically subtle but adversely affect outcomes in children harboring them.
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Affiliation(s)
- Abigail S. Carey
- Mindich Child Health & Development Institute, Icahn School of Medicine at Mount Sinai, New York
| | - Li Liang
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
| | - Jonathan Edwards
- Mindich Child Health & Development Institute, Icahn School of Medicine at Mount Sinai, New York
| | - Tracy Brandt
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
| | - Hui Mei
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
| | - Andrew J. Sharp
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
| | - Daphne T. Hsu
- Pediatric Cardiology, The Children’s Hospital at Montefiore, Bronx, NY
| | | | - Richard G. Ohye
- Dept of Cardiac Surgery, Section of Pediatric Cardiovascular Surgery, University of Michigan Medical School, Ann Arbor, MI
| | - Wendy K. Chung
- Dept of Pediatrics, Columbia University Medical Center, New York, NY
| | - Mark W. Russell
- Division of Pediatric Cardiology, C.S. Mott Children’s Hospital, University of Michigan, Ann Arbor, MI
| | | | - Lisa G. Shaffer
- Paw Print Genetics, Genetic Veterinary Sciences, Spokane, WA
| | - Michael K. Parides
- Dept of Health Evidence & Policy, Icahn School of Medicine at Mount Sinai, New York
| | - Lisa Edelmann
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
| | - Bruce D. Gelb
- Mindich Child Health & Development Institute, Icahn School of Medicine at Mount Sinai, New York
- Dept of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York
- Dept of Pediatrics, Icahn School of Medicine at Mount Sinai, New York
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29
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Atypical copy number abnormalities in 22q11.2 region: Report of three cases. Eur J Med Genet 2013; 56:515-20. [DOI: 10.1016/j.ejmg.2013.07.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Accepted: 07/05/2013] [Indexed: 11/23/2022]
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30
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Ribeiro-Bicudo LA, de Campos Legnaro C, Gamba BF, Candido Sandri RM, Richieri-Costa A. Cognitive deficit, learning difficulties, severe behavioral abnormalities and healed cleft lip in a patient with a 1.2-mb distal microduplication at 22q11.2. Mol Syndromol 2013; 4:292-6. [PMID: 24167465 DOI: 10.1159/000354095] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2013] [Indexed: 02/04/2023] Open
Abstract
The 22q11.2 duplication syndrome has been recently characterized as a new entity with features overlapping the 22q11.2 deletion syndrome. Most 22q11.2 duplications represent reciprocal events of the typical 3-Mb deletions extending between low copy repeat (LCR) 22-A and LCR22-D. It has been suggested that the clinical manifestations observed in patients with 22q11.2 microduplications may range from milder phenotypes to multiple severe defects, and this variability could be responsible for many undetected cases. Here, we report on a patient with a 1.2-Mb microduplication at 22q11.2 spanning LCR22-F and LCR22-H which harbor the SMARCB1 and SNRPD3 genes. The patient presented healed cleft lip, mild facial dysmorphism, cognitive deficit, and delayed language development associated with severe behavioral problems including learning difficulties and aggressive behavior.
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Affiliation(s)
- L A Ribeiro-Bicudo
- Division of Syndromology, Department of Clinical Genetics and Molecular Genetics, Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil ; Department of Genetics, University of São Paulo State, Botucatu, Brazil
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31
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Valvo G, Novara F, Brovedani P, Ferrari AR, Guerrini R, Zuffardi O, Sicca F. 22q11.2 Microduplication syndrome and epilepsy with continuous spikes and waves during sleep (CSWS). A case report and review of the literature. Epilepsy Behav 2012; 25:567-72. [PMID: 23159380 DOI: 10.1016/j.yebeh.2012.09.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 09/24/2012] [Accepted: 09/26/2012] [Indexed: 12/21/2022]
Abstract
Chromosome 22q11.2 microduplication syndrome is characterized by a variable and usually mild phenotype and by incomplete penetrance. Neurological features of the syndrome may entail intellectual or learning disability, motor delay, and other neurodevelopmental disorders. However, seizures or abnormal EEG are reported in a few cases. We describe a 6-year-old girl with microduplication of chromosome 22q11.2 and epilepsy with continuous spikes and waves during sleep (CSWS). Her behavioral disorder, characterized by hyperactivity, impulsiveness, attention deficit, and aggressiveness, became progressively evident a few months after epilepsy onset, suggesting a link with the interictal epileptic activity characterizing CSWS. We hypothesize that, at least in some cases, the neurodevelopmental deficit seen in the 22q11.2 microduplication syndrome could be the consequence of a disorder of cerebral electrogenesis, suggesting the need for an EEG recording in affected individuals. Moreover, an array-CGH analysis should be performed in all individuals with cryptogenic epilepsy and CSWS.
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Affiliation(s)
- Giulia Valvo
- Epilepsy, Neurophysiology and Neurogenetics Unit, IRCCS Stella Maris Foundation, Via dei Giacinti 2, 56128 Calambrone, Pisa, Italy
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32
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Abstract
PURPOSE OF REVIEW Chromosome 22, the first human chromosome to be completely sequenced, is prone to genomic alterations. Copy-number variants (CNVs) are common because of an enrichment of low-copy repeat sequences that precipitate a high frequency of nonallelic homologous misalignments and unequal recombination during meiosis. Among these is one of the most common multiple anomaly syndromes in humans and the most common microdeletion syndrome, velocardiofacial syndrome (VCFS), also known as 22q11.2 deletion syndrome and DiGeorge syndrome. This review will focus on the recent literature dealing with both the molecular and clinical aspects of chromosome 22 genomic variations. Although the literature covering this area is expansive, the majority is descriptive or analytical of the problems presented by these genomic disorders, and there is little evidence of translational research including treatment outcomes. RECENT FINDINGS With the increased use of microarray analysis in both research and clinical practice, variations in CNVs are becoming elucidated. Genomic analysis continues to characterize genes and gene effect. Research on the COMT gene continues to yield interesting findings, including a possible sex-mediated effect because of its regulatory role with estrogen. There is a small amount of treatment outcome data relevant to neuropsychiatric disorders in VCFS, but based on small samples and short-term follow-up. SUMMARY Although hundreds of studies in the past year have focused on genomic disorders of chromosome 22, little progress has been made in the implementation of translational research, even for more common disorders including VCFS.
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33
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Mona M, Mehrdad N, Mehrdad B, Elham N, Khazamipour N. Rearrangement in 22q11 implicated in Iranian patients with mental retardation. Int J Pediatr Otorhinolaryngol 2012; 76:1604-9. [PMID: 22939590 DOI: 10.1016/j.ijporl.2012.07.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 07/25/2012] [Accepted: 07/27/2012] [Indexed: 01/16/2023]
Abstract
Chromosome 22, particularly 22q11.2 region, is predisposed to rearrangements due to misalignments of low-copy repeats (LCRs). DiGeorge/velo-cardio-facial syndrome is a common disorder resulting from microdeletion within the same band. Although both deletion and duplication in this region are expected to occur in equal proportions as reciprocal events caused by LCR-mediated rearrangements, very few microduplications have been identified. The phenotype of these patients with microduplications is extremely diverse, ranging from normal to behavioral abnormalities to multiple defects, only some of which are reminiscent of the 22q11.2 deletion syndrome. The aim of this study was to investigate 22q11.2 microdeletion and microduplication among Iranian patients with mental retardation. For this purpose, 46 mental retarded patients who were tested negative for fragile X syndrome were involved in this study. The samples were assessed for 22q11.2 microduplication and microdeletions by Semi-Quantitative Multiplex Polymerase chain reaction (SQMPCR). MLPA was carried out to confirm the findings and to rule out other abnormalities in subtelomeric region. We found three patients with microdeletion and one with microduplication and one with 10p deletion syndrome. These findings proved evidence that microdeletion and microduplication of 22q11.2 can be a reason of mental retardation in Iranian population with unknown causes.
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Affiliation(s)
- Malekmohamadi Mona
- Department of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran
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34
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Weisfeld-Adams JD, Edelmann L, Gadi IK, Mehta L. Phenotypic heterogeneity in a family with a small atypical microduplication of chromosome 22q11.2 involving TBX1. Eur J Med Genet 2012; 55:732-6. [PMID: 23059467 DOI: 10.1016/j.ejmg.2012.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 08/31/2012] [Indexed: 01/25/2023]
Abstract
The chromosome 22q11.2 region is commonly involved in non-allelic homologous recombination (NAHR) events. Microduplications of 22q11.2, usually involving a 3 Mb or 1.5 Mb region constitute the 22q11 microduplication syndrome. Both microdeletions and microduplications of 22q11.21 are reported to share several phenotypic characteristics, including dysmorphic facial features, velopharyngeal insufficiency, congenital heart disease, urogenital abnormalities, and immunologic defects. We report a child who presented at 8 months of age for evaluation of microcephaly and mild motor delay. Head circumference at birth, at 8 months, and at 19 months of age was below the 3rd centile. Other findings included left-sided cryptorchidism and developmental dysplasia of the left hip. In addition, echocardiography revealed a restrictive patent ductus arteriosus. Chromosomal microarray analysis using Affymetrix Genome-Wide Human SNP Array 6.0 revealed a novel 437 kb interstitial duplication at 22q11.21, involving TBX1, whose breakpoints did not coincide with known low copy repeat (LCR) regions. The same duplication was confirmed by fluorescent in situ hybridization (FISH) in the patient's mother and an older sister. The mother has a history of anxiety disorder and depression. The sister had a history of delayed motor milestones. None of the three duplication carriers has any documented renal anomalies or other significant medical problems. This report demonstrates the clinical heterogeneity associated with microduplications of 22q11.2 and illustrates the difficulties related to providing prognostic information and accurate genetic counseling to families when this finding is detected. The described microduplication is the smallest in this genomic region reported to date and further implicates abnormal gene dosage of TBX1 in disorders resulting from 22q11.2 rearrangements.
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Affiliation(s)
- James D Weisfeld-Adams
- Department of Genetics & Genomic Sciences, Mount Sinai School of Medicine, New York, NY 10029, USA.
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35
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Belangero SI, Pacanaro ANX, Bellucco FT, Christofolini DM, Kulikowski LD, Guilherme RS, Bortolai A, Dutra ARN, Piazzon FB, Cernach MC, Melaragno MI. Wide clinical variability in cat eye syndrome patients: four non-related patients and three patients from the same family. Cytogenet Genome Res 2012; 138:5-10. [PMID: 22890013 DOI: 10.1159/000341570] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/21/2012] [Indexed: 11/19/2022] Open
Abstract
A small supernumerary marker chromosome (sSMC) derived from chromosome 22 is a relatively common cytogenetic finding. This sSMC typically results in tetrasomy for a chromosomal region that spans the chromosome 22p arm and the proximal 2 Mb of 22q11.21. Using classical cytogenetics, fluorescence in situ hybridization, multiplex ligation-dependent probe amplification, and array techniques, 7 patients with sSMCs derived from chromosome 22 were studied: 4 non-related and 3 from the same family (mother, daughter, and son). The sSMCs in all patients were dicentric and bisatellited chromosomes with breakpoints in the chromosome 22 low-copy repeat A region, resulting in cat eye syndrome (CES) due to chromosome 22 partial tetrasomy 22pter→q11.2 including the cat eye chromosome region. Although all subjects presented the same chromosomal abnormality, they showed a wide range of phenotypic differences, even in the 3 patients from the same family. There are no previous reports of CES occurring within 3 patients in the same family. Thus, the clinical and follow-up data presented here contribute to a better delineation of the phenotypes and outcomes of CES patients and will be useful for genetic counseling.
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Affiliation(s)
- S I Belangero
- Department of Morphology and Genetics, Universidade Federal de São Paulo, São Paulo, Brazil
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36
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Hiroi N, Hiramoto T, Harper KM, Suzuki G, Boku S. Mouse Models of 22q11.2-Associated Autism Spectrum Disorder. ACTA ACUST UNITED AC 2012; Suppl 1:001. [PMID: 25089229 PMCID: PMC4118685 DOI: 10.4172/2165-7890.s1-001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Copy number variation (CNV) of human chromosome 22q11.2 is associated with an elevated rate of autism spectrum disorder (ASD) and represents one of syndromic ASDs with rare genetic variants. However, the precise genetic basis of this association remains unclear due to its relatively large hemizygous and duplication region, including more than 30 genes. Previous studies using genetic mouse models suggested that although not all 22q11.2 genes contribute to ASD symptomatology, more than one 22q11.2 genes have distinct phenotypic targets for ASD symptoms. Our data show that deficiency of the two 22q11.2 genesTbx1 and Sept5 causes distinct phenotypic sets of ASD symptoms.
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Affiliation(s)
- Noboru Hiroi
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA ; Department of Neuroscience, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA ; Department of Genetics, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
| | - Takeshi Hiramoto
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
| | - Kathryn M Harper
- Department of Psychiatry & Behavioral Sciences, Northwestern University, Ward Building Room 9-258, 303 E. Chicago Ave. Chicago, IL 60611, USA
| | - Go Suzuki
- Department of Psychiatry, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan
| | - Shuken Boku
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Golding 104, 1300 Morris Park Avenue, Bronx, NY, 10461 USA
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37
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Goldmuntz E, Paluru P, Glessner J, Hakonarson H, Biegel JA, White PS, Gai X, Shaikh TH. Microdeletions and microduplications in patients with congenital heart disease and multiple congenital anomalies. CONGENIT HEART DIS 2011; 6:592-602. [PMID: 22010865 DOI: 10.1111/j.1747-0803.2011.00582.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Multiple genetic syndromes are caused by recurrent chromosomal microdeletions or microduplications. The increasing use of high-resolution microarrays in clinical analysis has allowed the identification of previously undetectable submicroscopic copy number variants (CNVs) associated with genetic disorders. We hypothesized that patients with congenital heart disease and additional dysmorphic features or other anomalies would be likely to harbor previously undetected CNVs, which might identify new disease loci or disease-related genes for various cardiac defects. DESIGN Copy number analysis with single nucleotide polymorphism-based, oligonucleotide microarrays was performed on 58 patients with congenital heart disease and other dysmorphic features and/or other anomalies. The observed CNVs were validated using independent techniques and validated CNVs were further analyzed using computational algorithms and comparison with available control CNV datasets in order to assess their pathogenic potential. RESULTS Potentially pathogenic CNVs were detected in twelve of 58 patients (20.7%), ranging in size from 240 Kb to 9.6 Mb. These CNVs contained between 1 and 55 genes, including NRP1, NTRK3, MESP1, ADAM19, and HAND1, all of which are known to participate in cardiac development. CONCLUSIONS Genome-wide analysis in patients with congenital heart disease and additional phenotypes has identified potentially pathogenic CNVs affecting genes involved in cardiac development. The identified variant loci and the genes within them warrant further evaluation in similarly syndromic and nonsyndromic cardiac cohorts.
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Affiliation(s)
- Elizabeth Goldmuntz
- Divisions of Cardiology Human Genetics Oncology Center for Applied Genomics Center for Biomedical Informatics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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38
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Yu S, Graf W, Ramalingam A, Brawner S, Joyce J, Fiedler S, Zhou XG, Liu HY. Identification of Copy Number Variants on Human Chromosome 22 in Patients with a Variety of Clinical Findings. Cytogenet Genome Res 2011; 134:260-8. [DOI: 10.1159/000330123] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/16/2011] [Indexed: 12/26/2022] Open
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Tan TY, Collins A, James PA, McGillivray G, Stark Z, Gordon CT, Leventer RJ, Pope K, Forbes R, Crolla JA, Ganesamoorthy D, Burgess T, Bruno DL, Slater HR, Farlie PG, Amor DJ. Phenotypic variability of distal 22q11.2 copy number abnormalities. Am J Med Genet A 2011; 155A:1623-33. [PMID: 21671380 DOI: 10.1002/ajmg.a.34051] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 03/17/2011] [Indexed: 01/09/2023]
Abstract
The availability of microarray technology has led to the recent recognition of copy number abnormalities of distal chromosome 22q11.2 that are distinct from the better-characterized deletions and duplications of the proximal region. This report describes five unrelated individuals with copy number abnormalities affecting distal chromosome 22q11.2. We report on novel phenotypic features including diaphragmatic hernia and uterine didelphys associated with the distal microdeletion syndrome; and frontomedial polymicrogyria and callosal agenesis associated with the distal microduplication syndrome. We describe the third distal chromosome 22q11.2 microdeletion patient with Goldenhar syndrome. Patients with distal chromosome 22q11.2 copy number abnormalities exhibit inter- and intra-familial phenotypic variability, and challenge our ability to draw meaningful genotype-phenotype correlations.
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40
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Wincent J, Bruno DL, van Bon BWM, Bremer A, Stewart H, Bongers EMHF, Ockeloen CW, Willemsen MH, Keays DDA, Baird G, Newbury DF, Kleefstra T, Marcelis C, Kini U, Stark Z, Savarirayan R, Sheffield LJ, Zuffardi O, Slater HR, de Vries BB, Knight SJL, Anderlid BM, Schoumans J. Sixteen New Cases Contributing to the Characterization of Patients with Distal 22q11.2 Microduplications. Mol Syndromol 2011; 1:246-254. [PMID: 22140377 DOI: 10.1159/000327982] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2011] [Indexed: 11/19/2022] Open
Abstract
The chromosome region 22q11.2 has long been recognized to be susceptible to genomic rearrangement. More recently, this genomic instability has been shown to extend distally (involving LCR22E-H) to the commonly deleted/duplicated region. To date, 21 index cases with 'distal' 22q11.2 duplications have been reported. We report on the clinical and molecular characterization of 16 individuals with distal 22q11.2 duplications identified by DNA microarray analysis. Two of the individuals have been partly described previously. The clinical phenotype varied among the patients in this study, although the majority displayed various degrees of developmental delay and speech disturbances. Other clinical features included behavioral problems, hypotonia, and dysmorphic facial features. Notably, none of the patients was diagnosed with a congenital heart defect. We found a high degree of inherited duplications. Additional copy number changes of unclear clinical significance were identified in 5 of our patients, and it is possible that these may contribute to the phenotypic expression in these patients as has been suggested recently in a 2-hit 'digenic' model for 16p12.1 deletions. The varied phenotypic expression and incomplete penetrance observed for distal 22q11.2 duplications makes it exceedingly difficult to ascribe pathogenicity for these duplications. Given the observed enrichment of the duplication in patient samples versus healthy controls, it is likely that distal 22q11.2 duplications represent a susceptibility/risk locus for speech and mild developmental delay.
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Affiliation(s)
- J Wincent
- Clinical Genetics Unit, Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
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22q11.2 microduplication in a family with recurrent fetal congenital heart disease. Eur J Med Genet 2011; 54:e433-6. [PMID: 21473936 DOI: 10.1016/j.ejmg.2011.03.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 03/20/2011] [Indexed: 11/21/2022]
Abstract
People carrying a 22q11.2 microduplication display a phenotype varying from normal to severely affected. We report a phenotypically normal female presented with a fetus having a severe congenital heart defect with ventricular septal defect, tricuspid atresia, patent ductus arteriosus and interrupted aortic arch. The pregnant woman had a history of overall three consecutive aberrant pregnancies with tetralogy of Fallot. Standard G-banding karyotype analysis of the parents and the actual pregnancy were normal, while array comparative genomic hybridization (arrayCGH) analysis revealed a 22q11.2 microduplication within the fetus' genome. Fluorescence in situ hybridization (FISH) and short tandem repeat polymorphism (STRP) tests indicated the affected fetus inherited the interstitial 22q11.2 microduplication from the mother. High-resolution oligonucleotide microarray analysis showed this microduplication is located in the common 3 Mb 22q11.2 deletion region between positions 17.298 Mb and 20.246 Mb with a length of 2.948 Mb. This report demonstrates the remarkable intrafamilial variability of a 22q11.2 microduplication phenotype. The 22q11.2 microduplication carried by one of the healthy parents has most likely contributed to the recurrent fetal heart defects.
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Abstract
Chromosome imbalances are the leading cause of intellectual and developmental disabilities in the population. This paper reviews the current methods used to diagnose chromosome abnormalities in children including karyotyping, fluorescence in situ hybridization and microarray technologies. Advances in molecular cytogenetics, especially with the use of microarrays, have substantially increased the detection of chromosome abnormalities in children with disabilities and congenital anomalies above that achievable with conventional cytogenetic banding and light microscopy.
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Wincent J, Anderlid BM, Lagerberg M, Nordenskjöld M, Schoumans J. High-resolution molecular karyotyping in patients with developmental delay and/or multiple congenital anomalies in a clinical setting. Clin Genet 2011; 79:147-57. [DOI: 10.1111/j.1399-0004.2010.01442.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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Soysal Y, Vermeesch J, Davani N, Şensoy N, Hekimler K, Imirzalıoğlu N. Case Report Molecular characterization of microduplication 22q11.2 in a girl with hypernasal speech. GENETICS AND MOLECULAR RESEARCH 2011; 10:2148-54. [DOI: 10.4238/vol10-3gmr1339] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Verhoeven W, Egger J, Brunner H, de Leeuw N. A patient with a de novo distal 22q11.2 microdeletion and anxiety disorder. Am J Med Genet A 2010; 155A:392-7. [PMID: 21271660 DOI: 10.1002/ajmg.a.33802] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 09/26/2010] [Indexed: 11/08/2022]
Abstract
We report on a young female with normal intelligence evaluated for long-term anxiety. Her history includes prematurity, neonatal feeding problems, surgical correction of congenital heart defects, recurrent upper airway and urinary tract infections, and delayed motor and developmental milestones. Physical examination disclosed small stature and minor dysmorphisms. Chromosome analysis, 22q11.2 FISH analysis, and subtelomeric MLPA testing did not detect any abnormalities. Genome wide SNP Array analysis showed a de novo deletion in 22q11.21q11.22, the so-called distal 22q11 microdeletion that involves the MAPK1 gene. A diagnosis of panic disorder was made and the patient was successfully treated with a daily dose of 20 mg citalopram. To our knowledge, this is the first adolescent patient with a long history of complaints about anxiety and a distal 22q11 microdeletion. We speculate that genes from the deleted region, especially MAPK1, increase the neurobiological susceptibility to anxiety disorders that may be a part of the psychopathological phenotype of the distal 22q11.2 microdeletion syndrome.
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Affiliation(s)
- Willem Verhoeven
- Vincent van Gogh Institute for Psychiatry, Centre of Excellence for Neuropsychiatry, Venray, The Netherlands.
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Sankaranarayanan K, Nikjoo H. Ionising radiation and genetic risks. XVI. A genome-based framework for risk estimation in the light of recent advances in genome research. Int J Radiat Biol 2010; 87:161-78. [DOI: 10.3109/09553002.2010.518214] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Girirajan S, Eichler EE. Phenotypic variability and genetic susceptibility to genomic disorders. Hum Mol Genet 2010; 19:R176-87. [PMID: 20807775 PMCID: PMC2953748 DOI: 10.1093/hmg/ddq366] [Citation(s) in RCA: 201] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 07/28/2010] [Accepted: 08/24/2010] [Indexed: 11/13/2022] Open
Abstract
The duplication architecture of the human genome predisposes our species to recurrent copy number variation and disease. Emerging data suggest that this mechanism of mutation contributes to both common and rare diseases. Two features regarding this form of mutation have emerged. First, common structural polymorphisms create susceptible and protective chromosomal architectures. These structural polymorphisms occur at varying frequencies in populations, leading to different susceptibility and ethnic predilection. Second, a subset of rearrangements shows extreme variability in expressivity. We propose that two types of genomic disorders may be distinguished: syndromic forms where the phenotypic features are largely invariant and those where the same molecular lesion associates with a diverse set of diagnoses including epilepsy, schizophrenia, autism, intellectual disability and congenital malformations. Copy number variation analyses of patient genomes reveal that disease type and severity may be explained by the occurrence of additional rare events and their inheritance within families. We propose that the overall burden of copy number variants creates differing sensitized backgrounds during development leading to different thresholds and disease outcomes. We suggest that the accumulation of multiple high-penetrant alleles of low frequency may serve as a more general model for complex genetic diseases, posing a significant challenge for diagnostics and disease management.
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Affiliation(s)
| | - Evan E. Eichler
- Department of Genome Sciences, Howard Hughes Medical Institute,University of Washington School of Medicine, PO Box 355065, Foege S413C, 3720 15th Avenue NE, Seattle, WA 98195, USA
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Abstract
Intellectual disability (ID) is the leading socio-economic problem of health care, but compared to autism and schizophrenia, it has received very little public attention. Important risk factors for ID are malnutrition, cultural deprivation, poor health care, and parental consanguinity. In the Western world, fetal alcohol exposure is the most common preventable cause. Most severe forms of ID have genetic causes. Cytogenetically detectable and submicroscopic chromosomal rearrangements account for approximately 25% of all cases. X-linked gene defects are responsible in 10-12% of males with ID; to date, 91 of these defects have been identified. In contrast, autosomal gene defects have been largely disregarded, but due to coordinated efforts and the advent of next-generation DNA sequencing, this is about to change. As shown for Fra(X) syndrome, this renewed focus on autosomal gene defects will pave the way for molecular diagnosis and prevention, shed more light on the pathogenesis of ID, and reveal new opportunities for therapy.
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A de novo 22q11.22q11.23 interchromosomal tandem duplication in a boy with developmental delay, hyperactivity, and epilepsy. Am J Med Genet A 2010; 152A:2820-6. [DOI: 10.1002/ajmg.a.33658] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Berg JS, Potocki L, Bacino CA. Common recurrent microduplication syndromes: diagnosis and management in clinical practice. Am J Med Genet A 2010; 152A:1066-78. [PMID: 20425813 DOI: 10.1002/ajmg.a.33185] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Details on the phenotypic consequences of genomic microdeletions and microduplications are rapidly emerging in the wake of increased utilization of high-resolution methods for the detection of genomic copy number variants (CNVs). Due to their recent discovery, the complete phenotypic characterization of these syndromes is still in progress. For practicing clinicians, this unprecedented molecular diagnostic capability has in many cases outpaced our ability to convey conclusive information regarding these conditions to patients and family members. In particular, genomic microduplication syndromes are frequently associated with variable phenotypes and incomplete penetrance, leading to difficulty in counseling regarding the potential future consequences of a given microduplication. In this review, we have attempted to provide an initial set of recommendations for the management of patients with recurrent microduplication syndromes. We summarize the clinical information for microduplications of 14 different genomic regions and provide a framework for clinical evaluation and anticipatory guidance in these conditions. It is our expectation that these preliminary guidelines will be revised further for each microduplication syndrome as more information becomes available.
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Affiliation(s)
- Jonathan S Berg
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
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