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Kozel BA, Barak B, Ae Kim C, Mervis CB, Osborne LR, Porter M, Pober BR. Williams syndrome. Nat Rev Dis Primers 2021; 7:42. [PMID: 34140529 PMCID: PMC9437774 DOI: 10.1038/s41572-021-00276-z] [Citation(s) in RCA: 86] [Impact Index Per Article: 28.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/13/2021] [Indexed: 11/09/2022]
Abstract
Williams syndrome (WS) is a relatively rare microdeletion disorder that occurs in as many as 1:7,500 individuals. WS arises due to the mispairing of low-copy DNA repetitive elements at meiosis. The deletion size is similar across most individuals with WS and leads to the loss of one copy of 25-27 genes on chromosome 7q11.23. The resulting unique disorder affects multiple systems, with cardinal features including but not limited to cardiovascular disease (characteristically stenosis of the great arteries and most notably supravalvar aortic stenosis), a distinctive craniofacial appearance, and a specific cognitive and behavioural profile that includes intellectual disability and hypersociability. Genotype-phenotype evidence is strongest for ELN, the gene encoding elastin, which is responsible for the vascular and connective tissue features of WS, and for the transcription factor genes GTF2I and GTF2IRD1, which are known to affect intellectual ability, social functioning and anxiety. Mounting evidence also ascribes phenotypic consequences to the deletion of BAZ1B, LIMK1, STX1A and MLXIPL, but more work is needed to understand the mechanism by which these deletions contribute to clinical outcomes. The age of diagnosis has fallen in regions of the world where technological advances, such as chromosomal microarray, enable clinicians to make the diagnosis of WS without formally suspecting it, allowing earlier intervention by medical and developmental specialists. Phenotypic variability is considerable for all cardinal features of WS but the specific sources of this variability remain unknown. Further investigation to identify the factors responsible for these differences may lead to mechanism-based rather than symptom-based therapies and should therefore be a high research priority.
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Affiliation(s)
- Beth A. Kozel
- Translational Vascular Medicine Branch, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, USA
| | - Boaz Barak
- The Sagol School of Neuroscience and The School of Psychological Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Chong Ae Kim
- Department of Pediatrics, Universidade de São Paulo, São Paulo, Brazil
| | - Carolyn B. Mervis
- Department of Psychological and Brain Sciences, University of Louisville, Louisville, USA
| | - Lucy R. Osborne
- Department of Medicine, University of Toronto, Ontario, Canada
| | - Melanie Porter
- Department of Psychology, Macquarie University, Sydney, Australia
| | - Barbara R. Pober
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Boston, USA
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Mosley TJ, Johnston HR, Cutler DJ, Zwick ME, Mulle JG. Sex-specific recombination patterns predict parent of origin for recurrent genomic disorders. BMC Med Genomics 2021; 14:154. [PMID: 34107974 PMCID: PMC8190997 DOI: 10.1186/s12920-021-00999-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 06/02/2021] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Structural rearrangements of the genome, which generally occur during meiosis and result in large-scale (> 1 kb) copy number variants (CNV; deletions or duplications ≥ 1 kb), underlie genomic disorders. Recurrent pathogenic CNVs harbor similar breakpoints in multiple unrelated individuals and are primarily formed via non-allelic homologous recombination (NAHR). Several pathogenic NAHR-mediated recurrent CNV loci demonstrate biases for parental origin of de novo CNVs. However, the mechanism underlying these biases is not well understood. METHODS We performed a systematic, comprehensive literature search to curate parent of origin data for multiple pathogenic CNV loci. Using a regression framework, we assessed the relationship between parental CNV origin and the male to female recombination rate ratio. RESULTS We demonstrate significant association between sex-specific differences in meiotic recombination and parental origin biases at these loci (p = 1.07 × 10-14). CONCLUSIONS Our results suggest that parental origin of CNVs is largely influenced by sex-specific recombination rates and highlight the need to consider these differences when investigating mechanisms that cause structural variation.
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Affiliation(s)
- Trenell J Mosley
- Graduate Program in Genetics and Molecular Biology, Laney Graduate School, Emory University, 201 Dowman Drive, Atlanta, GA, 30322, USA
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Whitehead Building Suite 300, Atlanta, GA, 30322, USA
| | - H Richard Johnston
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Whitehead Building Suite 300, Atlanta, GA, 30322, USA
- Emory Integrated Computational Core, Emory University, 101 Woodruff Circle, Atlanta, GA, 30322, USA
| | - David J Cutler
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Whitehead Building Suite 300, Atlanta, GA, 30322, USA
| | - Michael E Zwick
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Whitehead Building Suite 300, Atlanta, GA, 30322, USA
- Department of Pediatrics, Emory University School of Medicine, 2015 Uppergate Drive, Atlanta, GA, 30322, USA
| | - Jennifer G Mulle
- Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Whitehead Building Suite 300, Atlanta, GA, 30322, USA.
- Department of Epidemiology, Rollins School of Public Health, Emory University, 1518 Clifton Road NE, Atlanta, GA, 30322, USA.
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Young D, Klepacka D, McGarvey M, Schoolcraft WB, Katz-Jaffe MG. Infertility patients with chromosome inversions are not susceptible to an inter-chromosomal effect. J Assist Reprod Genet 2018; 36:509-516. [PMID: 30554392 DOI: 10.1007/s10815-018-1376-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 11/14/2018] [Indexed: 01/30/2023] Open
Abstract
PURPOSE The aim of this study was to evaluate the incidence of an inter-chromosomal effect (ICE) in blastocyst-stage embryos from carriers of balanced chromosome inversions. METHODS Infertility patients (n = 52) with balanced inversions (n = 66 cycles), and maternal age-matched controls that concurrently cycled (n = 66), consented to an IVF cycle with preimplantation genetic testing for aneuploidy (PGT-A). Blastocyst-stage embryos underwent trophectoderm biopsy for PGT-A with only euploid blastocysts transferred in a subsequent frozen embryo transfer. Subtypes of inversions were included in aggregate: paracentric/pericentric, polymorphic/non-polymorphic, male/female carriers, and varying inversion sizes. RESULTS The incidence of aneuploidy was not significantly higher for the inversion patients compared to the controls (inversion = 48.8% vs. control = 47.2% ns). Following euploid blastocyst transfer, there were excellent live birth outcomes. CONCLUSIONS Carriers of balanced chromosome inversions did not exhibit higher aneuploidy rates for chromosomes that were not involved in the inversion compared to maternal age-matched controls, signifying the absence of an inter-chromosomal effect for this data set. These results provide the largest investigation of blastocyst embryos regarding the debated existence of an ICE resulting from the presence of an inversion during meiosis. However, further studies are warranted to investigate an ICE among inversions subtypes that were outside the scope of this study.
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Affiliation(s)
- D Young
- Department of Genetics, Colorado Center for Reproductive Medicine, Lone Tree, USA
| | - D Klepacka
- Department of Genetics, Colorado Center for Reproductive Medicine, Lone Tree, USA
| | - M McGarvey
- Department of Genetics, Colorado Center for Reproductive Medicine, Lone Tree, USA
| | | | - M G Katz-Jaffe
- Colorado Center for Reproductive Medicine, 10290 RidgeGate Circle, Lone Tree, CO, 80124, USA.
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Faundes V, Santa María L, Morales P, Curotto B, Parraguez MM. Distal 7q11.23 Duplication, an Emerging Microduplication Syndrome: A Case Report and Further Characterisation. Mol Syndromol 2016; 7:287-291. [PMID: 27867344 DOI: 10.1159/000448698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2016] [Indexed: 11/19/2022] Open
Abstract
Chromosome 7q11.23 duplication syndrome is a well-recognised syndrome which involves the duplication of the same genes located in the Williams-Beuren critical region. However, in 2010, 4 patients were reported with a microduplication only in the HIP1 and YWHAG genes. We refer to this as a distal 7q11.23 duplication (dup7q11.23D). Here, we report the fifth de novo patient with dup7q11.23D, whose symptoms may be explained by YWHAG overexpression as was demonstrated recently in mice and obese patients. Finally, further studies will be necessary to delineate this emerging microduplication syndrome.
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Affiliation(s)
- Víctor Faundes
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Lorena Santa María
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Paulina Morales
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
| | - Bianca Curotto
- Laboratorio de Genética y Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile
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Sanders AD, Hills M, Porubský D, Guryev V, Falconer E, Lansdorp PM. Characterizing polymorphic inversions in human genomes by single-cell sequencing. Genome Res 2016; 26:1575-1587. [PMID: 27472961 PMCID: PMC5088599 DOI: 10.1101/gr.201160.115] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 06/13/2016] [Indexed: 12/23/2022]
Abstract
Identifying genomic features that differ between individuals and cells can help uncover the functional variants that drive phenotypes and disease susceptibilities. For this, single-cell studies are paramount, as it becomes increasingly clear that the contribution of rare but functional cellular subpopulations is important for disease prognosis, management, and progression. Until now, studying these associations has been challenged by our inability to map structural rearrangements accurately and comprehensively. To overcome this, we coupled single-cell sequencing of DNA template strands (Strand-seq) with custom analysis software to rapidly discover, map, and genotype genomic rearrangements at high resolution. This allowed us to explore the distribution and frequency of inversions in a heterogeneous cell population, identify several polymorphic domains in complex regions of the genome, and locate rare alleles in the reference assembly. We then mapped the entire genomic complement of inversions within two unrelated individuals to characterize their distinct inversion profiles and built a nonredundant global reference of structural rearrangements in the human genome. The work described here provides a powerful new framework to study structural variation and genomic heterogeneity in single-cell samples, whether from individuals for population studies or tissue types for biomarker discovery.
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Affiliation(s)
- Ashley D Sanders
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Mark Hills
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - David Porubský
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, NL-9713 AV Groningen, The Netherlands
| | - Victor Guryev
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, NL-9713 AV Groningen, The Netherlands
| | - Ester Falconer
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada
| | - Peter M Lansdorp
- Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, V5Z 1L3, Canada.,European Research Institute for the Biology of Ageing, University of Groningen, University Medical Centre Groningen, NL-9713 AV Groningen, The Netherlands.,Department of Medical Genetics, University of British Columbia, Vancouver, British Columbia, V6T 1Z4, Canada
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Poot M. A Loss or a Gain, Is It Not All the Same? Mol Syndromol 2016; 7:1-2. [PMID: 27194966 DOI: 10.1159/000443814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2015] [Indexed: 11/19/2022] Open
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Li L, Huang L, Luo Y, Huang X, Lin S, Fang Q. Differing Microdeletion Sizes and Breakpoints in Chromosome 7q11.23 in Williams-Beuren Syndrome Detected by Chromosomal Microarray Analysis. Mol Syndromol 2016; 6:268-75. [PMID: 27022327 DOI: 10.1159/000443942] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2015] [Indexed: 01/01/2023] Open
Abstract
Williams-Beuren syndrome (WBS) manifests as supravalvular aortic stenosis, intellectual disability, developmental delay and characteristic facial features. The common WBS deletion region ranges from 1.55 to 1.84 Mb and primarily contains the ELN gene. We analyzed 10 patients diagnosed with 7q11.23 microdeletion syndrome by chromosomal microarray analysis. The clinical features of these patients varied from classic WBS to normal phenotype. All 10 patients exhibited different sizes and breakpoints of chromosome microdeletions ranging from 44 kb to 9.88 Mb. The hemizygosity of the ELN gene was detected in 7 patients, while a normal ELN gene was present in 3 other patients with small deletions. We observed that the phenotypic features of WBS varied in fetuses, children and adults, influenced by the genes, deletion size and breakpoint. Our findings provide more information on the genotype-phenotype correlations of WBS. However, further research is needed to explore the size and breakpoint effect and functions of the genes on chromosome 7q11.23.
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Affiliation(s)
- Lin Li
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Linhuan Huang
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Yanmin Luo
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Xuan Huang
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Shaobin Lin
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Qun Fang
- Department of Gynecology and Obstetrics, Fetal Medicine Center, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
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Morris CA, Mervis CB, Paciorkowski AP, Abdul-Rahman O, Dugan SL, Rope AF, Bader P, Hendon LG, Velleman SL, Klein-Tasman BP, Osborne LR. 7q11.23 Duplication syndrome: Physical characteristics and natural history. Am J Med Genet A 2015; 167A:2916-35. [PMID: 26333794 PMCID: PMC5005957 DOI: 10.1002/ajmg.a.37340] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/08/2015] [Indexed: 01/17/2023]
Abstract
In order to describe the physical characteristics, medical complications, and natural history of classic 7q11.23 duplication syndrome [hereafter Dup7 (MIM 609757)], reciprocal duplication of the region deleted in Williams syndrome [hereafter WS (MIM 194050)], we systematically evaluated 53 individuals aged 1.25-21.25 years and 11 affected adult relatives identified in cascade testing. In this series, 27% of probands with Dup7 had an affected parent. Seven of the 26 de novo duplications that were examined for inversions were inverted; in all seven cases one of the parents had the common inversion polymorphism of the WS region. We documented the craniofacial features of Dup7: brachycephaly, broad forehead, straight eyebrows, broad nasal tip, low insertion of the columella, short philtrum, thin upper lip, minor ear anomalies, and facial asymmetry. Approximately 30% of newborns and 50% of older children and adults had macrocephaly. Abnormalities were noted on neurological examination in 88.7% of children, while 81.6% of MRI studies showed structural abnormalities such as decreased cerebral white matter volume, cerebellar vermis hypoplasia, and ventriculomegaly. Signs of cerebellar dysfunction were found in 62.3%, hypotonia in 58.5%, Developmental Coordination Disorder in 74.2%, and Speech Sound Disorder in 82.6%. Behavior problems included anxiety disorders, ADHD, and oppositional disorders. Medical problems included seizures, 19%; growth hormone deficiency, 9.4%; patent ductus arteriosus, 15%; aortic dilation, 46.2%; chronic constipation, 66%; and structural renal anomalies, 18%. We compare these results to the WS phenotype and offer initial recommendations for medical evaluation and surveillance of individuals who have Dup7.
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Affiliation(s)
- Colleen A. Morris
- Department of Pediatrics, University of Nevada School of Medicine, Las Vegas, NV
| | - Carolyn B. Mervis
- Department of Psychological and Brain Sciences, University of Louisville, Louisville, KY
| | - Alex P. Paciorkowski
- Center for Neural Development and Disease, Departments of Neurology, Pediatrics, and Biomedical Genetics, University of Rochester Medical Center, Rochester, NY
| | - Omar Abdul-Rahman
- Department of Pediatrics University of Mississippi Medical Center, Jackson, MS
| | - Sarah L. Dugan
- Division of Medical Genetics, University of Utah, Salt Lake City, UT
| | - Alan F. Rope
- Department of Medical Genetics, Kaiser Permanente, Portland OR
| | | | - Laura G. Hendon
- Department of Pediatrics University of Mississippi Medical Center, Jackson, MS
| | - Shelley L. Velleman
- Department of Communication Sciences and Disorders, University of Vermont, Burlington, VT
| | | | - Lucy R. Osborne
- Departments of Medicine and Molecular Genetics and Institute of Medical Science, University of Toronto, Toronto ON, Canada
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Discovery of structural alterations in solid tumor oligodendroglioma by single molecule analysis. BMC Genomics 2013; 14:505. [PMID: 23885787 PMCID: PMC3727977 DOI: 10.1186/1471-2164-14-505] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/23/2013] [Indexed: 12/31/2022] Open
Abstract
Background Solid tumors present a panoply of genomic alterations, from single base changes to the gain or loss of entire chromosomes. Although aberrations at the two extremes of this spectrum are readily defined, comprehensive discernment of the complex and disperse mutational spectrum of cancer genomes remains a significant challenge for current genome analysis platforms. In this context, high throughput, single molecule platforms like Optical Mapping offer a unique perspective. Results Using measurements from large ensembles of individual DNA molecules, we have discovered genomic structural alterations in the solid tumor oligodendroglioma. Over a thousand structural variants were identified in each tumor sample, without any prior hypotheses, and often in genomic regions deemed intractable by other technologies. These findings were then validated by comprehensive comparisons to variants reported in external and internal databases, and by selected experimental corroborations. Alterations range in size from under 5 kb to hundreds of kilobases, and comprise insertions, deletions, inversions and compound events. Candidate mutations were scored at sub-genic resolution and unambiguously reveal structural details at aberrant loci. Conclusions The Optical Mapping system provides a rich description of the complex genomes of solid tumors, including sequence level aberrations, structural alterations and copy number variants that power generation of functional hypotheses for oligodendroglioma genetics.
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Nadeau G, Coutton C, Amblard F, Michalowicz G, Frasca S, Fertin A, Devillard F, Satre V, Usson Y, Jouk PS. Interphase fluorescent in situ hybridization detection of the 7q11.23 chromosomal inversion in a clinical laboratory: automated versus manual scoring. Clin Chem Lab Med 2012; 51:e41-4. [PMID: 23072851 DOI: 10.1515/cclm-2012-0416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Accepted: 09/13/2012] [Indexed: 11/15/2022]
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Morris CA, Mervis CB, Osborne LR. Frequency of the 7q11.23 inversion polymorphism in transmitting parents of children with Williams syndrome and in the general population does not differ between North America and Europe. Mol Cytogenet 2011; 4:7. [PMID: 21356100 PMCID: PMC3055849 DOI: 10.1186/1755-8166-4-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2011] [Accepted: 02/28/2011] [Indexed: 11/10/2022] Open
Abstract
Inversion of the Williams syndrome (WS) region on chromosome 7q11.23 has previously been shown to occur at a higher frequency in the transmitting parents of children with WS than in the general population, suggesting that it predisposes to the WS deletion. Frohnauer et al. recently reported that the frequency of this inversion is not elevated in the parents of children with WS in Germany relative to the German general population. We have compared Frohnauer et al.'s data to those from three previously published studies (Hobart et al., Bayes et al., Osborne et al.), all of which reported a significantly higher rate of 7q11.23 inversion in transmitting parents than in the general population. Results indicated that Frohnauer et al.'s data are consistent with previously reported frequencies of 7q11.23 inversion in North America and Spain in both transmitting parents and the general population.
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Affiliation(s)
- Colleen A Morris
- Department of Pediatrics, University of Nevada School of Medicine, Las Vegas, Nevada, USA.
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Hobart HH, Morris CA, Mervis CB, Pani AM, Kistler DJ, Rios CM, Kimberley KW, Gregg RG, Bray-Ward P. Inversion of the Williams syndrome region is a common polymorphism found more frequently in parents of children with Williams syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2010; 154C:220-8. [PMID: 20425783 DOI: 10.1002/ajmg.c.30258] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Williams syndrome (WS) is a multisystem disorder caused by deletion of about 1.55 Mb of DNA (including 26 genes) on chromosome 7q11.23, a region predisposed to recombination due to its genomic structure. Deletion of the Williams syndrome chromosome region (WSCR) occurs sporadically. To better define chance for familial recurrence and to investigate the prevalence of genomic rearrangements of the region, 257 children with WS and their parents were studied. We determined deletion size in probands by metaphase FISH, parent-of-origin of the deleted chromosome by molecular genetic methods, and inversion status of the WSCR in both parents by interphase FISH. The frequency of WSCR inversion in the transmitting parent group was 24.9%. In contrast, the rate of inversion in the non-transmitting parent group (a reasonable estimate of the rate in the general population) was 5.8%. There were no significant gender differences with respect to parent-of-origin for the deleted chromosome or the incidence of the inversion polymorphism. There was no difference in the rate of spontaneous abortion for mothers heterozygous for the WSCR inversion relative to mothers without the inversion. We calculate that for a parent heterozygous for a WSCR inversion, the chance to have a child with WS is about 1 in 1,750, in contrast to the 1 in 9,500 chance for a parent without an inversion.
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Merla G, Brunetti-Pierri N, Micale L, Fusco C. Copy number variants at Williams–Beuren syndrome 7q11.23 region. Hum Genet 2010; 128:3-26. [DOI: 10.1007/s00439-010-0827-2] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Accepted: 04/13/2010] [Indexed: 01/06/2023]
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Transcriptome profile in Williams–Beuren syndrome lymphoblast cells reveals gene pathways implicated in glucose intolerance and visuospatial construction deficits. Hum Genet 2010; 128:27-37. [DOI: 10.1007/s00439-010-0817-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2010] [Accepted: 03/23/2010] [Indexed: 11/25/2022]
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Eisenberg DP, Jabbi M, Berman KF. Bridging the gene-behavior divide through neuroimaging deletion syndromes: Velocardiofacial (22q11.2 Deletion) and Williams (7q11.23 Deletion) syndromes. Neuroimage 2010; 53:857-69. [PMID: 20206275 DOI: 10.1016/j.neuroimage.2010.02.070] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Revised: 02/23/2010] [Accepted: 02/25/2010] [Indexed: 12/20/2022] Open
Abstract
Investigating the relationship between genes and the neural substrates of complex human behavior promises to provide essential insight into the pathophysiology of mental disorders. One approach to this inquiry is through neuroimaging of individuals with microdeletion syndromes that manifest in specific neuropsychiatric phenotypes. Both Velocardiofacial syndrome (VCFS) and Williams syndrome (WS) involve haploinsufficiency of a relatively small set of identified genes on the one hand and association with distinct, clinically relevant behavioral and cognitive profiles on the other hand. In VCFS, there is a deletion in chromosomal region 22q11.2 and a resultant predilection toward psychosis, poor arithmetic proficiency, and low performance intelligence quotients. In WS, there is a deletion in chromosomal region 7q11.23 and a resultant predilection toward hypersociability, non-social anxiety, impaired visuospatial construction, and often intellectual impairment. Structural and functional neuroimaging studies have begun not only to map these well-defined genetic alterations to systems-level brain abnormalities, but also to identify relationships between neural phenotypes and particular genes within the critical deletion regions. Though neuroimaging of both VCFS and WS presents specific, formidable methodological challenges, including comparison subject selection and accounting for neuroanatomical and vascular anomalies in patients, and many questions remain, the literature to date on these syndromes, reviewed herein, constitutes a fruitful "bottom-up" approach to defining gene-brain relationships.
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Affiliation(s)
- Daniel Paul Eisenberg
- Section on Integrative Neuroimaging, Clinical Brain Disorders Branch, Genes, Cognition and Psychosis Program National Institute of Mental Health, NIH, Intramural Research Program, DHHS, Bethesda, MD 20892-1365, USA
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Ferrero GB, Howald C, Micale L, Biamino E, Augello B, Fusco C, Turturo MG, Forzano S, Reymond A, Merla G. An atypical 7q11.23 deletion in a normal IQ Williams-Beuren syndrome patient. Eur J Hum Genet 2010; 18:33-8. [PMID: 19568270 DOI: 10.1038/ejhg.2009.108] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Williams-Beuren syndrome (WBS; OMIM no. 194050) is a multisystemic neurodevelopmental disorder caused by a hemizygous deletion of 1.55 Mb on chromosome 7q11.23 spanning 28 genes. Haploinsufficiency of the ELN gene was shown to be responsible for supravalvular aortic stenosis and generalized arteriopathy, whereas LIMK1, CLIP2, GTF2IRD1 and GTF2I genes were suggested to be linked to the specific cognitive profile and craniofacial features. These insights for genotype-phenotype correlations came from the molecular and clinical analysis of patients with atypical deletions and mice models. Here we report a patient showing mild WBS physical phenotype and normal IQ, who carries a shorter 1 Mb atypical deletion. This rearrangement does not include the GTF2IRD1 and GTF2I genes and only partially the BAZ1B gene. Our results are consistent with the hypothesis that hemizygosity of the GTF2IRD1 and GTF2I genes might be involved in the facial dysmorphisms and in the specific motor and cognitive deficits observed in WBS patients.
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Abstract
Significant advances have been made over the past 5 years in mapping and characterizing structural variation in the human genome. Despite this progress, our understanding of inversion variants is still very restricted. While unbalanced variants such as copy number variations can be mapped using array-based approaches, strategies for characterization of inversion variants have been limited and underdeveloped. Traditional cytogenetic approaches have long been able to identify microscopic inversion events, but discovery of submicroscopic events has remained elusive and largely ignored. With the advent of paired-end sequencing approaches, it is now possible to map inversions across the human genome. Based on the paired-end sequencing studies published to date, it is now feasible to make a first map of inversions across the human genome and to use this map to explore the characteristics and distribution of this form of variation. The current map of inversions indicates that many remain to be identified, especially in the smaller size ranges. This review provides an overview of the current knowledge about human inversions and their contribution to human phenotypes. Further characterization of inversions should be considered as an important step towards a deeper understanding of human variation and genome dynamics.
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Affiliation(s)
- Lars Feuk
- Department of Genetics and Pathology, Rudbeck Laboratory, Uppsala University, 751 85 Uppsala, Sweden.
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Affiliation(s)
- Barbara R Pober
- Center for Human Genetics, Massachusetts General Hospital, Boston, MA 02114, USA.
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