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Munezane H, Imamura K, Fujimoto N, Hotta A, Yukitake H, Inoue H. Elimination of the extra chromosome of Dup15q syndrome iPSCs for cellular and molecular investigation. Eur J Cell Biol 2024; 103:151446. [PMID: 39059105 DOI: 10.1016/j.ejcb.2024.151446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 06/23/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024] Open
Abstract
Chromosome 15q11.2-13.1 duplication (Dup15q) syndrome is one of the most common autism spectrum disorders (ASDs) associated with copy number variants (CNVs). For the analysis of CNV-relevant pathological cellular phenotypes, a CNV-corrected isogenic cell line is useful for excluding the influence of genetic background. Here, we devised a strategy to remove the isodicentric chromosome 15 by inserting a puro-ΔTK selection cassette into the extra chromosome using the CRISPR-Cas9 system, followed by a subsequent two-step drug selection. A series of assays, including qPCR-based copy number analysis and karyotype analysis, confirmed the elimination of the extra chromosome. Furthermore, cerebral organoids were generated from the parental Dup15q iPSCs and their isogenic iPSCs. scRNA-seq analysis revealed the alteration of expression levels in ion-channel-related genes and synapse-related genes in glutamatergic and GABAergic neurons in Dup15q organoids, respectively. The established isogenic cell line is a valuable resource for unraveling cellular and molecular alterations associated with Dup15q syndrome.
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Affiliation(s)
- Haruka Munezane
- Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan
| | - Keiko Imamura
- Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan; iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, 1-7 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237, Japan; Medical-Risk Avoidance based on iPS Cells Team, RIKEN Center for Advanced Intelligence Project (AIP), 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Naoko Fujimoto
- Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan
| | - Akitsu Hotta
- Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan
| | - Hiroshi Yukitake
- Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan; Global Advanced Platform, Takeda Pharmaceutical Company Limited, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan
| | - Haruhisa Inoue
- Center for iPS Cell Research and Application (CiRA), Kyoto University, 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan; Takeda-CiRA (T-CiRA) Joint Program, 2-26-1, Muraoka-Higashi, Fujisawa 251-8555, Japan; iPSC-based Drug discovery and Development Team, RIKEN BioResource Research Center, 1-7 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237, Japan; Medical-Risk Avoidance based on iPS Cells Team, RIKEN Center for Advanced Intelligence Project (AIP), 53 Shogoin Kawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan.
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Giovenale AMG, Ruotolo G, Soriano AA, Turco EM, Rotundo G, Casamassa A, D’Anzi A, Vescovi AL, Rosati J. Deepening the understanding of CNVs on chromosome 15q11-13 by using hiPSCs: An overview. Front Cell Dev Biol 2023; 10:1107881. [PMID: 36684422 PMCID: PMC9852989 DOI: 10.3389/fcell.2022.1107881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 12/16/2022] [Indexed: 01/09/2023] Open
Abstract
The human α7 neuronal nicotinic acetylcholine receptor gene (CHRNA7) is widely expressed in the central and peripheral nervous systems. This receptor is implicated in both brain development and adult neurogenesis thanks to its ability to mediate acetylcholine stimulus (Ach). Copy number variations (CNVs) of CHRNA7 gene have been identified in humans and are genetically linked to cognitive impairments associated with multiple disorders, including schizophrenia, bipolar disorder, epilepsy, Alzheimer's disease, and others. Currently, α7 receptor analysis has been commonly performed in animal models due to the impossibility of direct investigation of the living human brain. But the use of model systems has shown that there are very large differences between humans and mice when researchers must study the CNVs and, in particular, the CNV of chromosome 15q13.3 where the CHRNA7 gene is present. In fact, human beings present genomic alterations as well as the presence of genes of recent origin that are not present in other model systems as well as they show a very heterogeneous symptomatology that is associated with both their genetic background and the environment where they live. To date, the induced pluripotent stem cells, obtained from patients carrying CNV in CHRNA7 gene, are a good in vitro model for studying the association of the α7 receptor to human diseases. In this review, we will outline the current state of hiPSCs technology applications in neurological diseases caused by CNVs in CHRNA7 gene. Furthermore, we will discuss some weaknesses that emerge from the overall analysis of the published articles.
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Affiliation(s)
- Angela Maria Giada Giovenale
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy,Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Giorgia Ruotolo
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy,Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
| | - Amata Amy Soriano
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Elisa Maria Turco
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Giovannina Rotundo
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Alessia Casamassa
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Angela D’Anzi
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy
| | - Angelo Luigi Vescovi
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy,Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy,*Correspondence: Jessica Rosati, ; Angelo Luigi Vescovi,
| | - Jessica Rosati
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Italy,*Correspondence: Jessica Rosati, ; Angelo Luigi Vescovi,
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Casamassa A, Ferrari D, Gelati M, Carella M, Vescovi AL, Rosati J. A Link between Genetic Disorders and Cellular Impairment, Using Human Induced Pluripotent Stem Cells to Reveal the Functional Consequences of Copy Number Variations in the Central Nervous System-A Close Look at Chromosome 15. Int J Mol Sci 2020; 21:ijms21051860. [PMID: 32182809 PMCID: PMC7084702 DOI: 10.3390/ijms21051860] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/02/2020] [Accepted: 03/05/2020] [Indexed: 12/28/2022] Open
Abstract
Recent cutting-edge human genetics technology has allowed us to identify copy number variations (CNVs) and has provided new insights for understanding causative mechanisms of human diseases. A growing number of studies show that CNVs could be associated with physiological mechanisms linked to evolutionary trigger, as well as to the pathogenesis of various diseases, including cancer, autoimmune disease and mental disorders such as autism spectrum disorders, schizophrenia, intellectual disabilities or attention-deficit/hyperactivity disorder. Their incomplete penetrance and variable expressivity make diagnosis difficult and hinder comprehension of the mechanistic bases of these disorders. Additional elements such as co-presence of other CNVs, genomic background and environmental factors are involved in determining the final phenotype associated with a CNV. Genetically engineered animal models are helpful tools for understanding the behavioral consequences of CNVs. However, the genetic background and the biology of these animal model systems have sometimes led to confusing results. New cellular models obtained through somatic cellular reprogramming technology that produce induced pluripotent stem cells (iPSCs) from human subjects are being used to explore the mechanisms involved in the pathogenic consequences of CNVs. Considering the vast quantity of CNVs found in the human genome, we intend to focus on reviewing the current literature on the use of iPSCs carrying CNVs on chromosome 15, highlighting advantages and limits of this system with respect to mouse model systems.
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Affiliation(s)
- Alessia Casamassa
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Foggia, Italy;
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania Luigi Vanvitelli, Viale Abramo Lincoln 5, 81100 Caserta, Italy
| | - Daniela Ferrari
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy;
| | - Maurizio Gelati
- Fondazione IRCCS Casa Sollievo della Sofferenza, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Foggia, Italy; (M.G.); (M.C.)
| | - Massimo Carella
- Fondazione IRCCS Casa Sollievo della Sofferenza, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Foggia, Italy; (M.G.); (M.C.)
| | - Angelo Luigi Vescovi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy;
- Fondazione IRCCS Casa Sollievo della Sofferenza, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Foggia, Italy; (M.G.); (M.C.)
- Correspondence: (A.L.V.); (J.R.)
| | - Jessica Rosati
- Cellular Reprogramming Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, Viale dei Cappuccini 1, 71013 San Giovanni Rotondo, Foggia, Italy;
- Correspondence: (A.L.V.); (J.R.)
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Bacchelli E, Cameli C, Viggiano M, Igliozzi R, Mancini A, Tancredi R, Battaglia A, Maestrini E. An integrated analysis of rare CNV and exome variation in Autism Spectrum Disorder using the Infinium PsychArray. Sci Rep 2020; 10:3198. [PMID: 32081867 PMCID: PMC7035424 DOI: 10.1038/s41598-020-59922-3] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/19/2020] [Indexed: 01/11/2023] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental condition with a complex and heterogeneous genetic etiology. While a proportion of ASD risk is attributable to common variants, rare copy-number variants (CNVs) and protein-disrupting single-nucleotide variants (SNVs) have been shown to significantly contribute to ASD etiology. We analyzed a homogeneous cohort of 127 ASD Italian families genotyped with the Illumina PsychArray, to perform an integrated analysis of CNVs and SNVs and to assess their contribution to ASD risk. We observed a higher burden of rare CNVs, especially deletions, in ASD individuals versus unaffected controls. Furthermore, we identified a significant enrichment of rare CNVs intersecting ASD candidate genes reported in the SFARI database. Family-based analysis of rare SNVs genotyped by the PsychArray also indicated an increased transmission of rare SNV variants from heterozygous parents to probands, supporting a multigenic model of ASD risk with significant contributions of both variant types. Moreover, our study reinforced the evidence for a significant role of VPS13B, WWOX, CNTNAP2, RBFOX1, MACROD2, APBA2, PARK2, GPHN, and RNF113A genes in ASD susceptibility. Finally, we showed that the PsychArray, besides providing useful genotyping data in psychiatric disorders, is a valuable and cost-efficient tool for genic CNV detection, down to 10 kb.
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Affiliation(s)
- Elena Bacchelli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
| | - Cinzia Cameli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Marta Viggiano
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Roberta Igliozzi
- IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy
| | - Alice Mancini
- IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy
| | - Raffaella Tancredi
- IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy
| | - Agatino Battaglia
- IRCCS Stella Maris Foundation, Viale del Tirreno 331, 56128, Calambrone, Pisa, Italy
| | - Elena Maestrini
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
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Pavone P, Ruggieri M, Marino SD, Corsello G, Pappalardo X, Polizzi A, Parano E, Romano C, Marino S, Praticò AD, Falsaperla R. Chromosome 15q BP3 to BP5 deletion is a likely locus for speech delay and language impairment: Report on a four-member family and an unrelated boy. Mol Genet Genomic Med 2020; 8:e1109. [PMID: 31991071 PMCID: PMC7196468 DOI: 10.1002/mgg3.1109] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 12/11/2019] [Accepted: 12/16/2019] [Indexed: 01/13/2023] Open
Abstract
Background Deletions in chromosome 15q13 have been reported both in healthy people and individuals with a wide range of behavioral and neuropsychiatric disturbances. Six main breakpoint (BP) subregions (BP1‐BP6) are mapped to the 15q13 region and three further embedded BP regions (BP3‐BP5). The deletion at BP4‐BP5 is the rearrangement most frequently observed compared to other known deletions in BP3‐BP5 and BP3‐BP4 regions. Deletions of each of these three regions have previously been implicated in a variable range of clinical phenotypes, including minor dysmorphism, developmental delay/intellectual disability, epilepsy, autism spectrum disorders, behavioral disturbances, and speech disorders. Of note, no overt clinical difference among each group of BP region deletions has been recorded so far. Methods We report on a four‐member family plus an additional unrelated boy affected by a BP3‐BP5 deletion that presented with typical clinical signs including speech delay and language impairment. A review of the clinical features associated with the three main groups of BP regions (BP4‐BP5, BP3‐BP5, and BP3‐BP4) deletions is reported. Results Array‐CGH analysis revealed in the mother (case 1) and in her three children (cases 2, 3, and 4), as well as in the unrelated boy (case 5), the following rearrangement: arr (hg19) 15q13.1‐q13.3 (29.213.402–32.510.863) x1. Conclusion This report, along with other recent observations, suggests the hypothesis that the BP region comprised between BP3 and BP5 in chromosome 15q13 is involved in several brain human dysfunctions, including impairment of the language development and, its deletion, may be directly or indirectly responsible for the speech delay and language deficit in the affected individuals.
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Affiliation(s)
- Piero Pavone
- Unit of Clinical Pediatrics, University Hospital "Policlinico-Vittorio Emanuele", University of Catania, Catania, Italy.,Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Martino Ruggieri
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Simona D Marino
- Units of Pediatrics and Pediatric Emergency, University Hospital "Policlinico-Vittorio Emanuele", Catania, Italy
| | - Giovanni Corsello
- Units of Pediatrics and Neonatal Intensive Care, Department of Health Promotion of Maternal-Infantile Care and of Excellence Internal and Specialist Medicine "G. D'Alessandro" [PROMISE], University of Palermo, Palermo, Italy
| | - Xena Pappalardo
- National Council of Research, Institute for Research and Biomedical Innovation (IRIB), Unit of Catania, Catania, Italy
| | - Agata Polizzi
- Chair of Pediatrics, Department of Educational Sciences, University of Catania, Catania, Italy
| | - Enrico Parano
- National Council of Research, Institute for Research and Biomedical Innovation (IRIB), Unit of Catania, Catania, Italy
| | - Catia Romano
- Units of Pediatrics and Pediatric Emergency, University Hospital "Policlinico-Vittorio Emanuele", Catania, Italy
| | - Silvia Marino
- Units of Pediatrics and Pediatric Emergency, University Hospital "Policlinico-Vittorio Emanuele", Catania, Italy
| | - Andrea Domenico Praticò
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, Catania, Italy
| | - Raffaele Falsaperla
- Units of Pediatrics and Pediatric Emergency, University Hospital "Policlinico-Vittorio Emanuele", Catania, Italy
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Alsagob M, Salih MA, Hamad MHA, Al-Yafee Y, Al-Zahrani J, Al-Bakheet A, Nester M, Sakati N, Wakil SM, AlOdaib A, Colak D, Kaya N. First report of two successive deletions on chromosome 15q13 cytogenetic bands in a boy and girl: additional data to 15q13.3 syndrome with a report of high IQ patient. Mol Cytogenet 2019; 12:21. [PMID: 31131027 PMCID: PMC6525444 DOI: 10.1186/s13039-019-0432-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/01/2019] [Indexed: 11/10/2022] Open
Abstract
15q13.3 syndrome is associated with a wide spectrum of neurological disorders. Among a cohort of 150 neurodevelopmental cases, we identified two patients with two close proximity interstitial hemizygous deletions on chromosome 15q13. Using high-density microarrays, we characterized these deletions and their approximate breakpoints. The second deletion in both patients overlaps in a small area containing CHRNA7 where the gene is partially deleted. The CHRNA7 is considered a strong candidate for the 15q13.3 deletion syndrome's pathogenicity. Patient 1 has cognitive impairment, learning disabilities, hyperactivity and subtle dysmorphic features whereas patient 2 has mild language impairment with speech difficulty, mild dysmorphia, heart defect and interestingly a high IQ that has not been reported in 15q13.3 syndrome patients before. Our study presents first report of such two successive deletions in 15q13.3 syndrome patients and a high IQ in a 15q13.3 syndrome patient. Our study expands the breakpoints and phenotypic features related to 15q13.3 syndrome.
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Affiliation(s)
- Maysoon Alsagob
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Mustafa A Salih
- 2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Muddathir H A Hamad
- 2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Yusra Al-Yafee
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Jawaher Al-Zahrani
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Albandary Al-Bakheet
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Michael Nester
- 3Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Nadia Sakati
- 3Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Salma M Wakil
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Ali AlOdaib
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia
| | - Dilek Colak
- 4Department of Biostatistics, Epidemiology, and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Namik Kaya
- 1Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, Riyadh, 11211 Kingdom of Saudi Arabia.,2Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Identification of novel genomic imbalances in Saudi patients with congenital heart disease. Mol Cytogenet 2018; 11:9. [PMID: 29416564 PMCID: PMC5784682 DOI: 10.1186/s13039-018-0356-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Accepted: 01/03/2018] [Indexed: 11/10/2022] Open
Abstract
Background Quick genetic diagnosis of a patient with congenital heart disease (CHD) is quite important for proper health care and management. Copy number variations (CNV), chromosomal imbalances and rearrangements have been frequently associated with CHD. Previously, due to limitations of microscope based standard karyotyping techniques copious CNVs and submicroscopic imbalances could not be detected in numerous CHD patients. The aim of our study is to identify cytogenetic abnormalities among the selected CHD cases (n = 17) of the cohort using high density oligo arrays. Results Our screening study indicated that six patients (~35%) have various cytogenetic abnormalities. Among the patients, only patient 2 had a duplication whereas the rest carried various deletions. The patients 1, 4 and 6 have only single large deletions throughout their genome; a 3.2 Mb deletion on chromosome 7, a 3.35 Mb deletion on chromosome 3, and a 2.78 Mb a deletion on chromosome 2, respectively. Patients 3 and 5 have two deletions on different chromosomes. Patient 3 has deletions on chromosome 2 (2q24.1; 249 kb) and 16 (16q22.2; 1.8 Mb). Patient 4 has a 3.35 Mb an interstitial deletion on chromosome 3 (3q13.2q13.31).Based on our search on the latest available literature, our study is the first inclusive array CGH evaluation on Saudi cohort of CHD patients. Conclusions This study emphasizes the importance of the arrays in genetic diagnosis of CHD. Based on our results the high resolution arrays should be utilized as first-tier diagnostic tool in clinical care as suggested before by others. Moreover, previously evaluated negative CHD cases (based on standard karyotyping methods) should be re-examined by microarray based cytogenetic methods.
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Takumi T, Tamada K. CNV biology in neurodevelopmental disorders. Curr Opin Neurobiol 2018; 48:183-192. [PMID: 29331932 DOI: 10.1016/j.conb.2017.12.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 11/27/2017] [Accepted: 12/10/2017] [Indexed: 12/29/2022]
Abstract
Copy number variants (CNVs), characterized in recent years by cutting-edge technology, add complexity to our knowledge of the human genome. CNVs contribute not only to human diversity but also to different kinds of diseases including neurodevelopmental delay, autism spectrum disorder and neuropsychiatric diseases. Interestingly, many pathogenic CNVs are shared among these diseases. Studies suggest that pathophysiology of disease may not be simply attributed to a single driver gene within a CNV but also that multifactorial effects may be important. Gene expression and the resulting phenotypes may also be affected by epigenetic alteration and chromosomal structural changes. Combined with human genetics and systems biology, integrative research by multi-dimensional approaches using animal and cell models of CNVs are expected to further understanding of pathophysiological mechanisms of neurodevelopmental disorders and neuropsychiatric disorders.
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Affiliation(s)
- Toru Takumi
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan.
| | - Kota Tamada
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
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9
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Chrna7 deficient mice manifest no consistent neuropsychiatric and behavioral phenotypes. Sci Rep 2017; 7:39941. [PMID: 28045139 PMCID: PMC5206704 DOI: 10.1038/srep39941] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 11/28/2016] [Indexed: 11/22/2022] Open
Abstract
The alpha7 nicotinic acetylcholine receptor, encoded by the CHRNA7 gene, has been implicated in various psychiatric and behavioral disorders, including schizophrenia, bipolar disorder, epilepsy, autism, Alzheimer’s disease, and Parkinson’s disease, and is considered a potential target for therapeutic intervention. 15q13.3 microdeletion syndrome is a rare genetic disorder, caused by submicroscopic deletions on chromosome 15q. CHRNA7 is the only gene in this locus that has been deleted entirely in cases involving the smallest microdeletions. Affected individuals manifest variable neurological and behavioral phenotypes, which commonly include developmental delay/intellectual disability, epilepsy, and autism spectrum disorder. Subsets of patients have short attention spans, aggressive behaviors, mood disorders, or schizophrenia. Previous behavioral studies suggested that Chrna7 deficient mice had attention deficits, but were normal in baseline behavioral responses, learning, memory, and sensorimotor gating. Given a growing interest in CHRNA7-related diseases and a better appreciation of its associated human phenotypes, an in-depth behavioral characterization of the Chrna7 deficient mouse model appeared prudent. This study was designed to investigate whether Chrna7 deficient mice manifest phenotypes related to those seen in human individuals, using an array of 12 behavioral assessments and electroencephalogram (EEG) recordings on freely-moving mice. Examined phenotypes included social interaction, compulsive behaviors, aggression, hyperactivity, anxiety, depression, and somatosensory gating. Our data suggests that mouse behavior and EEG recordings are not sensitive to decreased Chrna7 copy number.
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Ziats MN, Goin-Kochel RP, Berry LN, Ali M, Ge J, Guffey D, Rosenfeld JA, Bader P, Gambello MJ, Wolf V, Penney LS, Miller R, Lebel RR, Kane J, Bachman K, Troxell R, Clark G, Minard CG, Stankiewicz P, Beaudet A, Schaaf CP. The complex behavioral phenotype of 15q13.3 microdeletion syndrome. Genet Med 2016; 18:1111-1118. [PMID: 26963284 DOI: 10.1038/gim.2016.9] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 01/09/2016] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Chromosome 15q13.3 represents a hotspot for genomic rearrangements due to repetitive sequences mediating nonallelic homologous recombination. Deletions of 15q13.3 have been identified in the context of multiple neurological and psychiatric disorders, but a prospective clinical and behavioral assessment of affected individuals has not yet been reported. METHODS Eighteen subjects with 15q13.3 microdeletion underwent a series of behavioral assessments, along with clinical history and physical examination, to comprehensively define their behavioral phenotypes. RESULTS Cognitive deficits are the most prevalent feature in 15q13.3 deletion syndrome, with an average nonverbal IQ of 60 among the patients studied. Autism spectrum disorder was highly penetrant, with 31% of patients meeting clinical criteria and exceeding cutoff scores on both ADOS-2 and ADI-R. Affected individuals exhibited a complex pattern of behavioral abnormalities, most notably hyperactivity, attention problems, withdrawal, and externalizing symptoms, as well as impairments in functional communication, leadership, adaptive skills, and activities of daily living. CONCLUSIONS The 15q13.3 deletion syndrome encompasses a heterogeneous behavioral phenotype that poses a major challenge to parents, caregivers, and treating providers. Further work to more clearly delineate genotype-phenotype relationships in 15q13.3 deletions will be important for anticipatory guidance and development of targeted therapies.Genet Med 18 11, 1111-1118.
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Affiliation(s)
- Mark N Ziats
- Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Robin P Goin-Kochel
- Autism Center, Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Leandra N Berry
- Autism Center, Texas Children's Hospital, Houston, Texas, USA.,Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - May Ali
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
| | - Jun Ge
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Danielle Guffey
- Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas, USA
| | - Jill A Rosenfeld
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | | | - Michael J Gambello
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Varina Wolf
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Lynette S Penney
- Department of Pediatrics, IWK Health Centre, Halifax, Nova Scotia, Canada
| | - Ryan Miller
- Section of Medical Genetics, Department of Pediatrics, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Robert Roger Lebel
- Section of Medical Genetics, Department of Pediatrics, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Jeffrey Kane
- 'Specially for Children Medical Group, Austin, Texas, USA
| | - Kristine Bachman
- Department of Pediatrics, Geisinger Medical Center, Danville, Pennsylvania, USA
| | | | - Gary Clark
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA
| | - Charles G Minard
- Dan L. Duncan Institute for Clinical and Translational Research, Baylor College of Medicine, Houston, Texas, USA
| | - Pawel Stankiewicz
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Arthur Beaudet
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Christian P Schaaf
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA
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11
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Copy Number Variation Screen Identifies a Rare De Novo Deletion at Chromosome 15q13.1-13.3 in a Child with Language Impairment. PLoS One 2015; 10:e0134997. [PMID: 26262844 PMCID: PMC4532445 DOI: 10.1371/journal.pone.0134997] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 07/17/2015] [Indexed: 01/15/2023] Open
Abstract
A significant proportion of children (up to 7% in the UK) present with pronounced language difficulties that cannot be explained by obvious causes like other neurological and medical conditions. A substantial genetic component is predicted to underlie such language problems. Copy number variants (CNVs) have been implicated in neurodevelopmental and psychiatric conditions, such as autism and schizophrenia, but it is not fully established to what extent they might contribute to language disorders. We conducted a CNV screen in a longitudinal cohort of young children with language-related difficulties (n = 85), focusing on single events at candidate loci. We detected a de novo deletion on chromosome 15q13.1–13.3. The adjacent 15q11-13.1 locus is disrupted in Prader-Willi and Angelman syndromes, while disruptions across the breakpoints (BP1-BP6) have previously been implicated in different neurodevelopmental phenotypes including autism, intellectual disability (ID), seizures and developmental delay (DD). This is the first report of a deletion at BP3-BP5 being linked to a deficit confined to language impairment, in the absence of ID, expanding the range of phenotypes that implicate the chromosome 15q13 locus.
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12
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Gillentine MA, Schaaf CP. The human clinical phenotypes of altered CHRNA7 copy number. Biochem Pharmacol 2015; 97:352-362. [PMID: 26095975 DOI: 10.1016/j.bcp.2015.06.012] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Accepted: 06/10/2015] [Indexed: 01/03/2023]
Abstract
Copy number variants (CNVs) have been implicated in multiple neuropsychiatric conditions, including autism spectrum disorder (ASD), schizophrenia, and intellectual disability (ID). Chromosome 15q13 is a hotspot for such CNVs due to the presence of low copy repeat (LCR) elements, which facilitate non-allelic homologous recombination (NAHR). Several of these CNVs have been overrepresented in individuals with neuropsychiatric disorders; yet variable expressivity and incomplete penetrance are commonly seen. Dosage sensitivity of the CHRNA7 gene, which encodes for the α7 nicotinic acetylcholine receptor in the human brain, has been proposed to have a major contribution to the observed cognitive and behavioral phenotypes, as it represents the smallest region of overlap to all the 15q13.3 deletions and duplications. Individuals with zero to four copies of CHRNA7 have been reported in the literature, and represent a range of clinical severity, with deletions causing generally more severe and more highly penetrant phenotypes. Potential mechanisms to account for the variable expressivity within each group of 15q13.3 CNVs will be discussed.
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Affiliation(s)
- Madelyn A Gillentine
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States
| | - Christian P Schaaf
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, United States; Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, United States.
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13
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PWS/AS MS-MLPA Confirms Maternal Origin of 15q11.2 Microduplication. Case Rep Genet 2015; 2015:474097. [PMID: 26064710 PMCID: PMC4439467 DOI: 10.1155/2015/474097] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/21/2015] [Indexed: 11/17/2022] Open
Abstract
The proximal region of the long arm of chromosome 15q11.2-q13 is associated with various neurodevelopmental disorders, including Prader-Willi (PWS) and Angelman (AS) syndromes, autism, and other developmental abnormalities resulting from deletions and duplications. In addition, this region encompasses imprinted genes that cause PWS or AS, depending on the parent-of-origin. This imprinting allows for diagnosis of PWS or AS based on methylation status using methylation sensitive (MS) multiplex ligation dependent probe amplification (MLPA). Maternally derived microduplications at 15q11.2-q13 have been associated with autism and other neuropsychiatric disorders. Multiple methods have been used to determine the parent-of-origin for 15q11.2-q13 microdeletions and microduplications. In the present study, a four-year-old nondysmorphic female patient with developmental delay was found to have a de novo ~5 Mb duplication within 15q11.2 by oligonucleotide genomic array. In order to determine the significance of this microduplication to the clinical phenotype, the parent-of-origin needed to be identified. The PWS/AS MS-MLPA assay is generally used to distinguish between deletion and uniparental disomy (UPD) of 15q11.2-q13, resulting in either PWS or AS. However, our study shows that PWS/AS MS-MLPA can also efficiently distinguish the parental origin of duplications of 15q11.2-q13.
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14
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Moreira DP, Griesi-Oliveira K, Bossolani-Martins AL, Lourenço NCV, Takahashi VNO, da Rocha KM, Moreira ES, Vadasz E, Meira JGC, Bertola D, Halloran EO, Magalhães TR, Fett-Conte AC, Passos-Bueno MR. Investigation of 15q11-q13, 16p11.2 and 22q13 CNVs in autism spectrum disorder Brazilian individuals with and without epilepsy. PLoS One 2014; 9:e107705. [PMID: 25255310 PMCID: PMC4177849 DOI: 10.1371/journal.pone.0107705] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Accepted: 08/21/2014] [Indexed: 11/18/2022] Open
Abstract
Copy number variations (CNVs) are an important cause of ASD and those located at 15q11-q13, 16p11.2 and 22q13 have been reported as the most frequent. These CNVs exhibit variable clinical expressivity and those at 15q11-q13 and 16p11.2 also show incomplete penetrance. In the present work, through multiplex ligation-dependent probe amplification (MLPA) analysis of 531 ethnically admixed ASD-affected Brazilian individuals, we found that the combined prevalence of the 15q11-q13, 16p11.2 and 22q13 CNVs is 2.1% (11/531). Parental origin could be determined in 8 of the affected individuals, and revealed that 4 of the CNVs represent de novo events. Based on CNV prediction analysis from genome-wide SNP arrays, the size of those CNVs ranged from 206 kb to 2.27 Mb and those at 15q11-q13 were limited to the 15q13.3 region. In addition, this analysis also revealed 6 additional CNVs in 5 out of 11 affected individuals. Finally, we observed that the combined prevalence of CNVs at 15q13.3 and 22q13 in ASD-affected individuals with epilepsy (6.4%) was higher than that in ASD-affected individuals without epilepsy (1.3%; p<0.014). Therefore, our data show that the prevalence of CNVs at 15q13.3, 16p11.2 and 22q13 in Brazilian ASD-affected individuals is comparable to that estimated for ASD-affected individuals of pure or predominant European ancestry. Also, it suggests that the likelihood of a greater number of positive MLPA results might be found for the 15q13.3 and 22q13 regions by prioritizing ASD-affected individuals with epilepsy.
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MESH Headings
- Adolescent
- Base Sequence
- Brazil
- Child
- Child Development Disorders, Pervasive/complications
- Child Development Disorders, Pervasive/genetics
- Chromosomes, Human/genetics
- Chromosomes, Human, Pair 15/genetics
- Chromosomes, Human, Pair 16/genetics
- Chromosomes, Human, Pair 22/genetics
- DNA Copy Number Variations
- Epilepsy/complications
- Female
- Genomics
- Humans
- Male
- Pedigree
- Polymorphism, Single Nucleotide
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Affiliation(s)
- Danielle P. Moreira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Karina Griesi-Oliveira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Ana L. Bossolani-Martins
- Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brasil
| | - Naila C. V. Lourenço
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Vanessa N. O. Takahashi
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Kátia M. da Rocha
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Eloisa S. Moreira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Estevão Vadasz
- Instituto de Psiquiatria do Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil
| | - Joanna Goes Castro Meira
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
| | - Debora Bertola
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
- Instituto da Criança da Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil
| | - Eoghan O’ Halloran
- Academic Centre on Rare Diseases, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Tiago R. Magalhães
- Academic Centre on Rare Diseases, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
- National Children’s Research Centre, Our Lady’s Children’s Hospital, Dublin, Ireland
| | - Agnes C. Fett-Conte
- Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brasil
| | - Maria Rita Passos-Bueno
- Centro de Pesquisas sobre o Genoma Humano e Células Tronco, Departamento de Genética e Biologia Evolutiva, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brasil
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15
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Girirajan S, Rosenfeld JA, Coe BP, Parikh S, Friedman N, Goldstein A, Filipink RA, McConnell JS, Angle B, Meschino WS, Nezarati MM, Asamoah A, Jackson KE, Gowans GC, Martin JA, Carmany EP, Stockton DW, Schnur RE, Penney LS, Martin DM, Raskin S, Leppig K, Thiese H, Smith R, Aberg E, Niyazov DM, Escobar LF, El-Khechen D, Johnson KD, Lebel RR, Siefkas K, Ball S, Shur N, McGuire M, Brasington CK, Spence JE, Martin LS, Clericuzio C, Ballif BC, Shaffer LG, Eichler EE. Phenotypic heterogeneity of genomic disorders and rare copy-number variants. N Engl J Med 2012; 367:1321-31. [PMID: 22970919 PMCID: PMC3494411 DOI: 10.1056/nejmoa1200395] [Citation(s) in RCA: 414] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Some copy-number variants are associated with genomic disorders with extreme phenotypic heterogeneity. The cause of this variation is unknown, which presents challenges in genetic diagnosis, counseling, and management. METHODS We analyzed the genomes of 2312 children known to carry a copy-number variant associated with intellectual disability and congenital abnormalities, using array comparative genomic hybridization. RESULTS Among the affected children, 10.1% carried a second large copy-number variant in addition to the primary genetic lesion. We identified seven genomic disorders, each defined by a specific copy-number variant, in which the affected children were more likely to carry multiple copy-number variants than were controls. We found that syndromic disorders could be distinguished from those with extreme phenotypic heterogeneity on the basis of the total number of copy-number variants and whether the variants are inherited or de novo. Children who carried two large copy-number variants of unknown clinical significance were eight times as likely to have developmental delay as were controls (odds ratio, 8.16; 95% confidence interval, 5.33 to 13.07; P=2.11×10(-38)). Among affected children, inherited copy-number variants tended to co-occur with a second-site large copy-number variant (Spearman correlation coefficient, 0.66; P<0.001). Boys were more likely than girls to have disorders of phenotypic heterogeneity (P<0.001), and mothers were more likely than fathers to transmit second-site copy-number variants to their offspring (P=0.02). CONCLUSIONS Multiple, large copy-number variants, including those of unknown pathogenic significance, compound to result in a severe clinical presentation, and secondary copy-number variants are preferentially transmitted from maternal carriers. (Funded by the Simons Foundation Autism Research Initiative and the National Institutes of Health.).
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Affiliation(s)
- Santhosh Girirajan
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
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16
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Deak KL, Horn SR, Rehder CW. The evolving picture of microdeletion/microduplication syndromes in the age of microarray analysis: variable expressivity and genomic complexity. Clin Lab Med 2011; 31:543-64, viii. [PMID: 22118736 DOI: 10.1016/j.cll.2011.08.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Several new microdeletion and microduplication syndromes have been discovered in a genotype-first approach. Many of these disorders are caused by nonallelic homologous recombination between blocks of segmental duplication. The authors describe 9 regions for which copy number alteration is proposed to cause an abnormal phenotype. Some of these disorders have been observed in affected individuals and individuals lacking a clearly abnormal phenotype. These deletions and duplications are thought to be contributory, but not always sufficient, to elicit an abnormal outcome. Additional studies are necessary to further evaluate the penetrance and delineate the clinical spectrum associated with many of these newly described disorders.
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Affiliation(s)
- Kristen L Deak
- Department of Pathology, Duke University, Durham, NC, USA
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17
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Dagli A, Buiting K, Williams CA. Molecular and Clinical Aspects of Angelman Syndrome. Mol Syndromol 2011; 2:100-112. [PMID: 22670133 DOI: 10.1159/000328837] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The Angelman syndrome is caused by disruption of the UBE3A gene and is clinically delineated by the combination of severe mental disability, seizures, absent speech, hypermotoric and ataxic movements, and certain remarkable behaviors. Those with the syndrome have a predisposition toward apparent happiness and paroxysms of laughter, and this finding helps distinguish Angelman syndrome from other conditions involving severe developmental handicap. Accurate diagnosis rests on a combination of clinical criteria and molecular and/or cytogenetic testing. Analysis of parent-specific DNA methylation imprints in the critical 15q11.2-q13 genomic region identifies 75-80% of all individuals with the syndrome, including those with cytogenetic deletions, imprinting center defects and paternal uniparental disomy. In the remaining group, UBE3A sequence analysis identifies an additional percentage of patients, but 5-10% will remain who appear to have the major clinical phenotypic features but do not have any identifiable genetic abnormalities. Genetic counseling for recurrence risk is complicated because multiple genetic mechanisms can disrupt the UBE3A gene, and there is also a unique inheritance pattern associated with UBE3A imprinting. Angelman syndrome is a prototypical developmental syndrome due to its remarkable behavioral phenotype and because UBE3A is so crucial to normal synaptic function and neural plasticity.
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Affiliation(s)
- A Dagli
- Raymond C. Philips Unit, Division of Genetics and Metabolism, Department of Pediatrics, University of Florida, Gainesville, Fla., USA
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