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Unolt M, Versacci P, Anaclerio S, Lambiase C, Calcagni G, Trezzi M, Carotti A, Crowley TB, Zackai EH, Goldmuntz E, Gaynor JW, Digilio MC, McDonald-McGinn DM, Marino B. Congenital heart diseases and cardiovascular abnormalities in 22q11.2 deletion syndrome: From well-established knowledge to new frontiers. Am J Med Genet A 2018; 176:2087-2098. [PMID: 29663641 DOI: 10.1002/ajmg.a.38662] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 02/12/2018] [Accepted: 02/13/2018] [Indexed: 12/11/2022]
Abstract
Congenital heart diseases (CHDs) and cardiovascular abnormalities are one of the pillars of clinical diagnosis of 22q11.2 deletion syndrome (22q11.2DS) and still represent the main cause of mortality in the affected children. In the past 30 years, much progress has been made in describing the anatomical patterns of CHD, in improving their diagnosis, medical treatment, and surgical procedures for these conditions, as well as in understanding the underlying genetic and developmental mechanisms. However, further studies are still needed to better determine the true prevalence of CHDs in 22q11.2DS, including data from prenatal studies and on the adult population, to further clarify the genetic mechanisms behind the high variability of phenotypic expression of 22q11.2DS, and to fully understand the mechanism responsible for the increased postoperative morbidity and for the premature death of these patients. Moreover, the increased life expectancy of persons with 22q11.2DS allowed the expansion of the adult population that poses new challenges for clinicians such as acquired cardiovascular problems and complexity related to multisystemic comorbidity. In this review, we provide a comprehensive review of the existing literature about 22q11.2DS in order to summarize the knowledge gained in the past years of clinical experience and research, as well as to identify the remaining gaps in comprehension of this syndrome and the possible future research directions.
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Affiliation(s)
- Marta Unolt
- Department of Pediatrics and Pediatric Neuropsychiatry, "Sapienza" University of Rome, Rome, Italy
| | - Paolo Versacci
- Department of Pediatrics and Pediatric Neuropsychiatry, "Sapienza" University of Rome, Rome, Italy
| | - Silvia Anaclerio
- Department of Pediatrics and Pediatric Neuropsychiatry, "Sapienza" University of Rome, Rome, Italy
| | - Caterina Lambiase
- Department of Pediatrics and Pediatric Neuropsychiatry, "Sapienza" University of Rome, Rome, Italy
| | - Giulio Calcagni
- Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome, Italy
| | - Matteo Trezzi
- Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome, Italy
| | - Adriano Carotti
- Department of Pediatric Cardiology and Cardiac Surgery, Bambino Gesù Pediatric Hospital, Rome, Italy
| | - Terrence Blaine Crowley
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Elaine H Zackai
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Elizabeth Goldmuntz
- The Cardiac Center, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - James William Gaynor
- The Cardiac Center, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | - Donna M McDonald-McGinn
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Bruno Marino
- Department of Pediatrics and Pediatric Neuropsychiatry, "Sapienza" University of Rome, Rome, Italy
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Calcagni G, Unolt M, Digilio MC, Baban A, Versacci P, Tartaglia M, Baldini A, Marino B. Congenital heart disease and genetic syndromes: new insights into molecular mechanisms. Expert Rev Mol Diagn 2017; 17:861-870. [PMID: 28745539 DOI: 10.1080/14737159.2017.1360766] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Advances in genetics allowed a better definition of the role of specific genetic background in the etiology of syndromic congenital heart defects (CHDs). The identification of a number of disease genes responsible for different syndromes have led to the identification of several transcriptional regulators and signaling transducers and modulators that are critical for heart morphogenesis. Understanding the genetic background of syndromic CHDs allowed a better characterization of the genetic basis of non-syndromic CHDs. In this sense, the well-known association of typical CHDs in Down syndrome, 22q11.2 microdeletion and Noonan syndrome represent paradigms as chromosomal aneuploidy, chromosomal microdeletion and intragenic mutation, respectively. Area covered: For each syndrome the anatomical features, distinctive cardiac phenotype and molecular mechanisms are discussed. Moreover, the authors include recent genetic findings that may shed light on some aspects of still unclear molecular mechanisms of these syndromes. Expert commentary: Further investigations are needed to enhance the translational approach in the field of genetics of CHDs. When there is a well-established definition of genotype-phenotype (reverse medicine) and genotype-prognosis (predictive and personalized medicine) correlations, hopefully preventive medicine will make its way in this field. Subsequently a reduction will be achieved in the morbidity and mortality of children with CHDs.
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Affiliation(s)
- Giulio Calcagni
- a Department of Pediatric Cardiology and Cardiac Surgery , Bambino Gesù Children's Hospital and Research Institute , Rome , Italy
| | - Marta Unolt
- b Department of Pediatrics , Sapienza University , Rome , Italy
| | - Maria Cristina Digilio
- c Genetics and Rare Diseases Research Division , Bambino Gesù Children's Hospital and Research Institute , Rome , Italy
| | - Anwar Baban
- a Department of Pediatric Cardiology and Cardiac Surgery , Bambino Gesù Children's Hospital and Research Institute , Rome , Italy
| | - Paolo Versacci
- b Department of Pediatrics , Sapienza University , Rome , Italy
| | - Marco Tartaglia
- c Genetics and Rare Diseases Research Division , Bambino Gesù Children's Hospital and Research Institute , Rome , Italy
| | - Antonio Baldini
- d CNR Institute of Genetics and Biophysics Adriano Buzzati Traverso; Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II , Naples , Italy
| | - Bruno Marino
- b Department of Pediatrics , Sapienza University , Rome , Italy
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A deletion and a duplication in distal 22q11.2 deletion syndrome region. Clinical implications and review. BMC MEDICAL GENETICS 2009; 10:48. [PMID: 19490635 PMCID: PMC2700091 DOI: 10.1186/1471-2350-10-48] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2008] [Accepted: 06/02/2009] [Indexed: 12/31/2022]
Abstract
Background Individuals affected with DiGeorge and Velocardiofacial syndromes present with both phenotypic diversity and variable expressivity. The most frequent clinical features include conotruncal congenital heart defects, velopharyngeal insufficiency, hypocalcemia and a characteristic craniofacial dysmorphism. The etiology in most patients is a 3 Mb recurrent deletion in region 22q11.2. However, cases of infrequent deletions and duplications with different sizes and locations have also been reported, generally with a milder, slightly different phenotype for duplications but with no clear genotype-phenotype correlation to date. Methods We present a 7 month-old male patient with surgically corrected ASD and multiple VSDs, and dysmorphic facial features not clearly suggestive of 22q11.2 deletion syndrome, and a newborn male infant with cleft lip and palate and upslanting palpebral fissures. Karyotype, FISH, MLPA, microsatellite markers segregation studies and SNP genotyping by array-CGH were performed in both patients and parents. Results Karyotype and FISH with probe N25 were normal for both patients. MLPA analysis detected a partial de novo 1.1 Mb deletion in one patient and a novel partial familial 0.4 Mb duplication in the other. Both of these alterations were located at a distal position within the commonly deleted region in 22q11.2. These rearrangements were confirmed and accurately characterized by microsatellite marker segregation studies and SNP array genotyping. Conclusion The phenotypic diversity found for deletions and duplications supports a lack of genotype-phenotype correlation in the vicinity of the LCRC-LCRD interval of the 22q11.2 chromosomal region, whereas the high presence of duplications in normal individuals supports their role as polymorphisms. We suggest that any hypothetical correlation between the clinical phenotype and the size and location of these alterations may be masked by other genetic and/or epigenetic modifying factors.
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Abstract
MicroRNAs (miRNAs) are key regulators of messenger RNA (mRNA) translation known to be involved in a wide variety of cellular processes. In fact, their individual importance is reflected in the diseases that may arise upon the loss, mutation or dysfunction of specific miRNAs. It has been appreciated only recently that diseases may also develop when the protein components of the miRNA machinery itself are affected. The core enzymes of the major protein complexes involved in miRNA biogenesis and function, such as the ribonucleases III (RNases III) Drosha and Dicer as well as Argonaute 2 (Ago2), appear to be essential. However, the accessory proteins of the miRNA pathway, such as the DiGeorge syndrome critical region gene 8 (DGCR8) protein, Exportin-5 (Exp-5), TAR RNA binding protein (TRBP) and fragile X mental retardation protein (FMRP), are each related, in various ways, to specific genetic diseases.
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Affiliation(s)
| | - Patrick Provost
- Corresponding author: Patrick Provost, Centre de Recherche en Rhumatologie et Immunologie, 2705 Blvd Laurier, Local T1-49, Quebec, QC, G1V 4G2 Canada, Phone: 1 418 656 4141 (ext. 48842), Fax: 1 418 654 2765,
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Spiteri E, Babcock M, Kashork CD, Wakui K, Gogineni S, Lewis DA, Williams KM, Minoshima S, Sasaki T, Shimizu N, Potocki L, Pulijaal V, Shanske A, Shaffer LG, Morrow BE. Frequent translocations occur between low copy repeats on chromosome 22q11.2 (LCR22s) and telomeric bands of partner chromosomes. Hum Mol Genet 2003; 12:1823-37. [PMID: 12874103 DOI: 10.1093/hmg/ddg203] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The chromosome 22q11.2 region is susceptible to rearrangements, mediated by low copy repeats (LCR22s). Deletions and duplications are mediated by homologous recombination events between LCR22s. The recurrent balanced constitutional translocation t(11;22)(q23;q11) breakpoint occurs in an LCR22 and is mediated by double strand breaks in AT-rich palindromes on both chromosomes 11 and 22. Recently, two cases of a t(17;22)(q11;q11) were reported, mediated by a similar mechanism (21). Except for these constitutional translocations, the molecular basis for non-recurrent, reciprocal 22q11.2 translocations is not known. To determine whether there are specific mechanisms that could mediate translocations, we analyzed cell lines derived from 14 different individuals by genotyping and FISH mapping. Somatic cell hybrid analysis was carried out for four cell lines. In five cell lines, the translocation breakpoints occurred in the same LCR22 as for the t(11;22) translocation, suggesting that similar molecular mechanisms are responsible. An additional three occurred in other LCR22s, and six were in non-LCR22 regions, mostly in the proximal half of the 22q11.2 region. The translocation breakpoints on the partner chromosomes were all located in the telomeric bands, proximal to the most telomeric unique sequence probe, in eight cell lines and distal to those loci in six. Therefore, several of the breakpoints were found to occur in the vicinity of highly dynamic regions of the genome, 22q11.2 and telomeric bands. We hypothesize that these regions are more susceptible to breakage and repair, resulting in translocations.
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Affiliation(s)
- Elizabeth Spiteri
- Department of Molecular Genetics, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Shiohama A, Sasaki T, Noda S, Minoshima S, Shimizu N. Molecular cloning and expression analysis of a novel gene DGCR8 located in the DiGeorge syndrome chromosomal region. Biochem Biophys Res Commun 2003; 304:184-90. [PMID: 12705904 DOI: 10.1016/s0006-291x(03)00554-0] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We have identified and cloned a novel gene (DGCR8) from the human chromosome 22q11.2. This gene is located in the DiGeorge syndrome chromosomal region (DGCR). It consists of 14 exons spanning over 35kb and produces transcripts with ORF of 2322bp, encoding a protein of 773 amino acids. We also isolated a mouse ortholog Dgcr8 and found it has 95.3% identity with human DGCR8 at the amino acid sequence level. Northern blot analysis of human and mouse tissues from adult and fetus showed rather ubiquitous expression. However, the in situ hybridization of mouse embryos revealed that mouse Dgcr8 transcripts are localized in neuroepithelium of primary brain, limb bud, vessels, thymus, and around the palate during the developmental stages of embryos. The expression profile of Dgcr8 in developing mouse embryos is consistent with the clinical phenotypes including congenital heart defects and palate clefts associated with DiGeorge syndrome (DGS)/conotruncal anomaly face syndrome (CAFS)/velocardiofacial syndrome (VCFS), which are caused by monoallelic microdeletion of chromosome 22q11.2.
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Affiliation(s)
- Aiko Shiohama
- Department of Molecular Biology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, 160-8582, Tokyo, Japan
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McDermid HE, Morrow BE. Genomic disorders on 22q11. Am J Hum Genet 2002; 70:1077-88. [PMID: 11925570 PMCID: PMC447586 DOI: 10.1086/340363] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2002] [Accepted: 02/18/2002] [Indexed: 11/03/2022] Open
Abstract
The 22q11 region is involved in chromosomal rearrangements that lead to altered gene dosage, resulting in genomic disorders that are characterized by mental retardation and/or congenital malformations. Three such disorders-cat-eye syndrome (CES), der(22) syndrome, and velocardiofacial syndrome/DiGeorge syndrome (VCFS/DGS)-are associated with four, three, and one dose, respectively, of parts of 22q11. The critical region for CES lies centromeric to the deletion region of VCFS/DGS, although, in some cases, the extra material in CES extends across the VCFS/DGS region. The der(22) syndrome region overlaps both the CES region and the VCFS/DGS region. Molecular approaches have revealed a set of common chromosome breakpoints that are shared between the three disorders, implicating specific mechanisms that cause these rearrangements. Most VCFS/DGS and CES rearrangements are likely to occur by homologous recombination events between blocks of low-copy repeats (e.g., LCR22), whereas nonhomologous recombination mechanisms lead to the constitutional t(11;22) translocation. Meiotic nondisjunction events in carriers of the t(11;22) translocation can then lead to offspring with der(22) syndrome. The molecular basis of the clinical phenotype of these genomic disorders has also begun to be addressed. Analysis of both the genomic sequence for the 22q11 interval and the orthologous regions in the mouse has identified >24 genes that are shared between VCFS/DGS and der(22) syndrome and has identified 14 putative genes that are shared between CES and der(22) syndrome. The ability to manipulate the mouse genome aids in the identification of candidate genes in these three syndromes. Research on genomic disorders on 22q11 will continue to expand our knowledge of the mechanisms of chromosomal rearrangements and the molecular basis of their phenotypic consequences.
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Affiliation(s)
- Heather E. McDermid
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta; and Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY
| | - Bernice E. Morrow
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta; and Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY
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8
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Abstract
Identifying the genes that underlie the pathogenesis of chromosome deletion and duplication syndromes is a challenge because the affected chromosomal segment can contain many genes. The identification of genes that are relevant to these disorders often requires the analysis of individuals that carry rare, small deletions, translocations or single-gene mutations. Research into the chromosome 22 deletion (del22q11) syndrome, which encompasses DiGeorge and velocardiofacial syndrome, has taken a different path in recent years, using mouse models to circumvent the paucity of informative human material. These mouse models have provided new insights into the pathogenesis of del22q11 syndrome and have established strategies for research into chromosomal-deletion and -duplication syndromes.
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Affiliation(s)
- E A Lindsay
- Division of Cardiology, Department of Pediatrics, Baylor College of Medicine, 1 Baylor Plaza, Houston, Texas 77030, USA.
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Wouters CH, Meijers-Heijboer HJ, Eussen BJ, van der Heide AA, van Luijk RB, van Drunen E, Beverloo BB, Visscher F, Van Hemel JO. Deletions at chromosome regions 7q11.23 and 7q36 in a patient with Williams syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 2001; 102:261-5. [PMID: 11484204 DOI: 10.1002/ajmg.1468] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
We report on a patient with Williams syndrome and a complex de novo chromosome rearrangement, including microdeletions at 7q11.23 and 7q36 and additional chromosomal material at 7q36. The nature of this additional material was elucidated by spectral karyotyping and first assigned to chromosome 22. Subsequent fluorescence in situ hybridization (FISH) experiments showed that it consisted of satellite material only. Refinement of the 7q36 breakpoint was performed with several FISH probes, showing a deletion distal to the triphalangeal thumb (TPT) region. The phenotype of the patient principally results from the microdeletion of the 7q11.23; the small deletion at 7qter and the extra satellite material may not be of clinical significance.
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Affiliation(s)
- C H Wouters
- Department of Clinical Genetics, University Hospital Dijkzigt and Erasmus University, Rotterdam, The Netherlands.
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10
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Diagnosis of Microdeletion Syndromes by Fluorescence in situ Hybridization (
FISH
). ACTA ACUST UNITED AC 2001; Chapter 8:Unit 8.10. [DOI: 10.1002/0471142905.hg0810s14] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
Numerous syndromes affecting patients have phenotypes that include congenital heart defects (CHDs). These disorders have fascinated physicians for many years, raising questions about how seemingly disparate aspects of human development can be perturbed together in striking, but consistent, ways. Paralleling the major advances in human genetics during recent decades, we have come to understand that some of these syndromes arise from gross defects in chromosomal number, some from subtler alterations in genomic regions, and still others from point mutations in specific genes. These disorders, largely mendelian in nature, have provided researchers with the wherewithal to discover disease genes underlying CHD. Although some of these medical conditions are relatively rare, their solution has often provided insights that could be applied toward understanding the basis of nonsyndromic CHD. In this review, recent progress toward uncovering the molecular basis of several forms of syndromic CHD is discussed.
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Affiliation(s)
- B D Gelb
- Departments of Pediatrics and Human Genetics, Mount Sinai School of Medicine, New York, New York 10029, USA.
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Edelmann L, Stankiewicz P, Spiteri E, Pandita RK, Shaffer L, Lupski J, Morrow BE. Two Functional Copies of the DGCR6 Gene Are Present on Human Chromosome 22q11 Due to a Duplication of an Ancestral Locus. Genome Res 2001. [DOI: 10.1101/gr.143101] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The DGCR6 (DiGeorge critical region) gene encodes a putative protein with sequence similarity to gonadal(gdl), a Drosophila melanogaster gene of unknown function. We mapped the DGCR6 gene to chromosome 22q11 within a low copy repeat, termed sc11.1a, and identified a second copy of the gene, DGCR6L, within the duplicate locus, termed sc11.1b. Both sc11.1 repeats are deleted in most persons with velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS), and they map immediately adjacent and internal to the low copy repeats, termed LCR22, that mediate the deletions associated with VCFS/DGS. We sequenced genomic clones from both loci and determined that the putative initiator methionine is located further upstream than originally described, but in a position similar to the mouse and chicken orthologs.DGCR6L encodes a highly homologous, functional copy ofDGCR6, with some base changes rendering amino acid differences. Expression studies of the two genes indicate that both genes are widely expressed in fetal and adult tissues. Evolutionary studies using FISH mapping in several different species of ape combined with sequence analysis of DGCR6 in a number of different primate species indicate that the duplication is at least 12 million years old and may date back to before the divergence of Catarrhines from Platyrrhines, 35 mya. These data suggest that there has been selective evolutionary pressure toward the functional maintenance of both paralogs. Interestingly, a full-length HERV-K provirus integrated into the sc11.1a locus after the divergence of chimpanzees and humans.
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13
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Adachi R, Nigam R, Tuvim MJ, DeMayo F, Dickey BF. Genomic organization, chromosomal localization, and expression of the murine RAB3D gene. Biochem Biophys Res Commun 2000; 273:877-83. [PMID: 10891340 DOI: 10.1006/bbrc.2000.3032] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Rab proteins, members of the Ras superfamily of small GTPases, play regulatory roles in intercompartmental vesicular transport. Each step of traffic seems to require the participation of at least one distinct Rab, with the Rab3 subfamily involved in stimulated exocytosis. We report our studies on the murine rab3D gene, one of the four mammalian Rab3 isoforms. We located this gene on chromosome 13, region A(2-3). The rab3D gene consists of 5 exons spanning 10.6 kb, and the structural gene is contained in exons 2 through 5 with one canonical GTP-binding motif in each exon. Organization of the rab3D gene is identical to that of rab3A but different from other rab genes. Alternative poly-A(+) signals in the 3' untranslated region account for the identities of multiple transcripts detected by Northern blot analysis. Rab3D is expressed in all tissues studied, predominantly in heart, lung, and liver, and binding sites for multiple transcription factors are found in the TATA-less promoter region.
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Affiliation(s)
- R Adachi
- Department of Medicine, Baylor College of Medicine, Houston, Texas 77030, USA.
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14
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Novelli G, Amati F, Dallapiccola B. Individual haploinsufficient loci and the complex phenotype of DiGeorge syndrome. MOLECULAR MEDICINE TODAY 2000; 6:10-1. [PMID: 10637567 DOI: 10.1016/s1357-4310(99)01577-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Kimber WL, Hsieh P, Hirotsune S, Yuva-Paylor L, Sutherland HF, Chen A, Ruiz-Lozano P, Hoogstraten-Miller SL, Chien KR, Paylor R, Scambler PJ, Wynshaw-Boris A. Deletion of 150 kb in the minimal DiGeorge/velocardiofacial syndrome critical region in mouse. Hum Mol Genet 1999; 8:2229-37. [PMID: 10545603 DOI: 10.1093/hmg/8.12.2229] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Deletions or rearrangements of human chromosome 22q11 lead to a variety of related clinical syndromes such as DiGeorge syndrome (DGS) and velo--cardiofacial syndrome (VCFS). In addition, patients with 22q11 deletions have an increased incidence of schizophrenia and several studies have mapped susceptibility loci for schizophrenia to this region. Human molecular genetic studies have so far failed to identify the crucial genes or disruption mechanisms that result in these disorders. We have used gene targeting in the mouse to delete a defined region within the conserved DGS critical region (DGCR) on mouse chromosome 16 to prospectively investigate the role of the mouse DGCR in 22q11 syndromes. The deletion spans a conserved portion ( approximately 150 kb) of the proximal region of the DGCR, containing at least seven genes ( Znf74l, Idd, Tsk1, Tsk2, Es2, Gscl and Ctp ). Mice heterozygous for this deletion display no findings of DGS/VCFS in either inbred or mixed backgrounds. However, heterozygous mice display an increase in prepulse inhibition of the startle response, a manifestation of sensorimotor gating that is reduced in humans with schizophrenia. Homozygous deleted mice die soon after implantation, demonstrating that the deleted region contains genes essential for early post-implantation embryonic development. These results suggest that heterozygous deletion of this portion of the DGCR is sufficient for sensorimotor gating abnormalities, but not sufficient to produce the common features of DGS/VCFS in the mouse.
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Affiliation(s)
- W L Kimber
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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16
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Abstract
22q11 deletion syndrome (22qDS) is due to microdeletions of chromosome region 22q11.2. Little is known about the phenotype of adults. We reviewed available case reports of adults (age >/=18 years) with 22qDS and compared the prevalence of key findings to those reported in a large European survey of 22qDS (497 children and 61 adults) [Ryan et al., 1997: J. Med. Genet. 34:798-804]. Fifty-five studies reported on 126 adults (83 women, 40 men, 3 unknown sex), mean age 29.6 years (SD = 8.7 years). Compared with the European survey, adults with 22qDS reviewed had a lower rate of CHD, 30% versus 75%; chi(2) = 88.65, df = 1, P < 0.0001, but higher rates of identified palate anomalies, 88% versus 15%; chi(2) = 37.45, df = 1, P < 0.0001, and learning difficulties, 94% versus 79%; chi(2) = 12.13, df = 1, P = < 0.0008. The most common finding reported was minor facial anomalies. Few reports provided details of minor physical anomalies. Psychiatric conditions were more prevalent, 36% versus 18%; chi(2)= 5.71, df = 1, P < 0.02, than in the survey: 60% of reviewed adults were transmitting parents (72% mothers) ascertained following diagnosis of affected offspring. They had lower rates of CHD, cleft palate, and psychiatric disorders but similar rates of learning disabilities, and other palate and facial anomalies compared with adults ascertained by other methods. The results suggest that learning disabilities and facial and palate anomalies may be key findings in 22qDS adults, but that ascertainment is a key factor in the observed phenotype. Comprehensive studies of adults with 22qDS identified independently of familial transmission are necessary to further delineate the phenotype of adults and to determine the natural history of the syndrome.
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Affiliation(s)
- E Cohen
- Schizophrenia Research Program, Queen Street Division, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
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Edelmann L, Pandita RK, Morrow BE. Low-copy repeats mediate the common 3-Mb deletion in patients with velo-cardio-facial syndrome. Am J Hum Genet 1999; 64:1076-86. [PMID: 10090893 PMCID: PMC1377832 DOI: 10.1086/302343] [Citation(s) in RCA: 234] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Velo-cardio-facial syndrome (VCFS) is the most common microdeletion syndrome in humans. It occurs with an estimated frequency of 1 in 4, 000 live births. Most cases occur sporadically, indicating that the deletion is recurrent in the population. More than 90% of patients with VCFS and a 22q11 deletion have a similar 3-Mb hemizygous deletion, suggesting that sequences at the breakpoints confer susceptibility to rearrangements. To define the region containing the chromosome breakpoints, we constructed an 8-kb-resolution physical map. We identified a low-copy repeat in the vicinity of both breakpoints. A set of genetic markers were integrated into the physical map to determine whether the deletions occur within the repeat. Haplotype analysis with genetic markers that flank the repeats showed that most patients with VCFS had deletion breakpoints in the repeat. Within the repeat is a 200-kb duplication of sequences, including a tandem repeat of genes/pseudogenes, surrounding the breakpoints. The genes in the repeat are GGT, BCRL, V7-rel, POM121-like, and GGT-rel. Physical mapping and genomic fingerprint analysis showed that the repeats are virtually identical in the 200-kb region, suggesting that the deletion is mediated by homologous recombination. Examination of two three-generation families showed that meiotic intrachromosomal recombination mediated the deletion.
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Affiliation(s)
- L Edelmann
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Funke B, Edelmann L, McCain N, Pandita RK, Ferreira J, Merscher S, Zohouri M, Cannizzaro L, Shanske A, Morrow BE. Der(22) syndrome and velo-cardio-facial syndrome/DiGeorge syndrome share a 1.5-Mb region of overlap on chromosome 22q11. Am J Hum Genet 1999; 64:747-58. [PMID: 10053009 PMCID: PMC1377792 DOI: 10.1086/302284] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Derivative 22 (der[22]) syndrome is a rare disorder associated with multiple congenital anomalies, including profound mental retardation, preauricular skin tags or pits, and conotruncal heart defects. It can occur in offspring of carriers of the constitutional t(11;22)(q23;q11) translocation, owing to a 3:1 meiotic malsegregation event resulting in partial trisomy of chromosomes 11 and 22. The trisomic region on chromosome 22 overlaps the region hemizygously deleted in another congenital anomaly disorder, velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS). Most patients with VCFS/DGS have a similar 3-Mb deletion, whereas some have a nested distal deletion endpoint resulting in a 1.5-Mb deletion, and a few rare patients have unique deletions. To define the interval on 22q11 containing the t(11;22) breakpoint, haplotype analysis and FISH mapping were performed for five patients with der(22) syndrome. Analysis of all the patients was consistent with 3:1 meiotic malsegregation in the t(11;22) carrier parent. FISH-mapping studies showed that the t(11;22) breakpoint occurred in the same interval as the 1.5-Mb distal deletion breakpoint for VCFS. The deletion breakpoint of one VCFS patient with an unbalanced t(18;22) translocation also occurred in the same region. Hamster-human somatic hybrid cell lines from a patient with der(22) syndrome and a patient with VCFS showed that the breakpoints occurred in an interval containing low-copy repeats, distal to RANBP1 and proximal to ZNF74. The presence of low-copy repetitive sequences may confer susceptibility to chromosome rearrangements. A 1.5-Mb region of overlap on 22q11 in both syndromes suggests the presence of dosage-dependent genes in this interval.
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Affiliation(s)
- B Funke
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Lindsay EA, Baldini A. Congenital heart defects and 22q11 deletions: which genes count? MOLECULAR MEDICINE TODAY 1998; 4:350-7. [PMID: 9755454 DOI: 10.1016/s1357-4310(98)01302-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Hemizygous deletions on the long arm of chromosome 22 (del22q11) are a relatively common cause of congenital heart disease. For some specific heart defects such as interrupted aortic arch type B and tetralogy of Fallot with absent pulmonary valve, del22q11 is probably the most frequent genetic cause. Although extensive gene searches have been successful in discovering many novel genes in the deleted segment, standard positional cloning has so far failed to demonstrate a role for any of these genes in the disease. We show how the use of experimental animal models is beginning to provide an insight into the developmental role of some of these genes, while novel genome manipulation technologies promise to dissect the genetic aspects of this complex syndrome.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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Yamagishi H, Ishii C, Maeda J, Kojima Y, Matsuoka R, Kimura M, Takao A, Momma K, Matsuo N. Phenotypic discordance in monozygotic twins with 22q11.2 deletion. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1096-8628(19980724)78:4<319::aid-ajmg3>3.0.co;2-g] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Funke B, Saint-Jore B, Puech A, Sirotkin H, Edelmann L, Carlson C, Raft S, Pandita RK, Kucherlapati R, Skoultchi A, Morrow BE. Characterization and mutation analysis of goosecoid-like (GSCL), a homeodomain-containing gene that maps to the critical region for VCFS/DGS on 22q11. Genomics 1997; 46:364-72. [PMID: 9441739 DOI: 10.1006/geno.1997.5046] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Velocardiofacial syndrome (VCFS) is a developmental disorder characterized by conotruncal heart defects, craniofacial anomalies, and learning disabilities. VCFS is phenotypically related to DiGeorge syndrome (DGS) and both syndromes are associated with hemizygous 22q11 deletions. Because many of the tissues and structures affected in VCFS/DGS derive from the pharyngeal arches of the developing embryo, it is believed that haploinsufficiency of a gene(s) involved in embryonic development may be responsible for its etiology. A homeodomain-containing gene, Goosecoidlike (GSCL), has been recently described, and it resides in the critical region for VCFS/DGS on 22q11. GSCL is related to the Goosecoid gene (GSC) in both sequence of the homeodomain and genomic organization. Gsc in the mouse is expressed during early and midembryogenesis and is required for craniofacial rib, and limb development. The chick homolog of GSCL, termed GSX, is expressed during early chick embryogenesis. We detected GSCL expression in human embryos and biphasic expression in mouse embryos. It is possible that the vertebrate GSCL gene is also required for embryonic development. Due to its location in the critical region on 22q11, GSCL is an excellent candidate gene for VCFS/DGS. The vertebrate GSC protein has the same DNA binding specificity as the Drosophila morphogen, bicoid. Upon examination of the putative GSCL promoter, we found three sequence elements with an exact match to the reverse complement of the bicoid DNA recognition motif, suggesting that GSC, or possibly GSCL itself, regulates the transcription of GSCL. Sequence analysis of the putative promoter and the coding region of GSCL was performed on the DNA template from 17 VCFS patients who did not have a detectable 22q11 deletion to identify mutations. We did not detect a mutation in this set of VCFS patients. A polymorphism was detected in codon 47 of exon 1.
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Affiliation(s)
- B Funke
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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22
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Botta A, Lindsay EA, Jurecic V, Baldini A. Comparative mapping of the DiGeorge syndrome region in mouse shows inconsistent gene order and differential degree of gene conservation. Mamm Genome 1997; 8:890-5. [PMID: 9383280 DOI: 10.1007/s003359900606] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have constructed a comparative map in mouse of the critical region of human 22q11 deleted in DiGeorge (DGS) and Velocardiofacial (VCFS) syndromes. The map includes 11 genes potentially haploinsufficient in these deletion syndromes. We have localized all the conserved genes to mouse Chromosome (Chr) 16, bands B1-B3. The determination of gene order shows the presence of two regions (distal and proximal), containing two groups of conserved genes. The gene order in the two regions is not completely conserved; only in the proximal group is the gene order identical to human. In the distal group the gene order is inverted. These two regions are separated by a DNA segment containing at least one gene which, in the human DGS region, is the most proximal of the known deleted genes. In addition, the gene order within the distal group of genes is inverted relative to the human gene order. Furthermore, a clathrin heavy chain-like gene was not found in the mouse genome by DNA hybridization, indicating that there is an inconsistent level of gene conservation in the region. These and other independent data obtained in our laboratory clearly show a complex evolutionary history of the DGS-VCFS region. Our data provide a framework for the development of a mouse model for the 22q11 deletion with chromosome engineering technologies.
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Affiliation(s)
- A Botta
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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23
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Pragliola A, Jurecic V, Chau CK, Philip N, Baldini A. Goosecoid-like sequences and the smallest region of deletion overlap in DiGeorge and velocardiofacial syndromes. Am J Hum Genet 1997; 61:1456-9. [PMID: 9399910 PMCID: PMC1716100 DOI: 10.1086/301652] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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24
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Dasouki M, Jurecic V, Phillips JA, Whitlock JA, Baldini A. DiGeorge anomaly and chromosome 10p deletions: One or two loci? ACTA ACUST UNITED AC 1997. [DOI: 10.1002/(sici)1096-8628(19971128)73:1<72::aid-ajmg14>3.0.co;2-o] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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26
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27
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Carlson C, Sirotkin H, Pandita R, Goldberg R, McKie J, Wadey R, Patanjali SR, Weissman SM, Anyane-Yeboa K, Warburton D, Scambler P, Shprintzen R, Kucherlapati R, Morrow BE. Molecular definition of 22q11 deletions in 151 velo-cardio-facial syndrome patients. Am J Hum Genet 1997; 61:620-9. [PMID: 9326327 PMCID: PMC1715959 DOI: 10.1086/515508] [Citation(s) in RCA: 281] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Velo-cardio-facial syndrome (VCFS) is a relatively common developmental disorder characterized by craniofacial anomalies and conotruncal heart defects. Many VCFS patients have hemizygous deletions for a part of 22q11, suggesting that haploinsufficiency in this region is responsible for its etiology. Because most cases of VCFS are sporadic, portions of 22q11 may be prone to rearrangement. To understand the molecular basis for chromosomal deletions, we defined the extent of the deletion, by genotyping 151 VCFS patients and performing haplotype analysis on 105, using 15 consecutive polymorphic markers in 22q11. We found that 83% had a deletion and >90% of these had a similar approximately 3 Mb deletion, suggesting that sequences flanking the common breakpoints are susceptible to rearrangement. We found no correlation between the presence or size of the deletion and the phenotype. To further define the chromosomal breakpoints among the VCFS patients, we developed somatic hybrid cell lines from a set of VCFS patients. An 11-kb resolution physical map of a 1,080-kb region that includes deletion breakpoints was constructed, incorporating genes and expressed sequence tags (ESTs) isolated by the hybridization selection method. The ordered markers were used to examine the two separated copies of chromosome 22 in the somatic hybrid cell lines. In some cases, we were able to map the chromosome breakpoints within a single cosmid. A 480-kb critical region for VCFS has been delineated, including the genes for GSCL, CTP, CLTD, HIRA, and TMVCF, as well as a number of novel ordered ESTs.
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Affiliation(s)
- C Carlson
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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28
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Lewin MB, Lindsay EA, Jurecic V, Goytia V, Towbin JA, Baldini A. A genetic etiology for interruption of the aortic arch type B. Am J Cardiol 1997; 80:493-7. [PMID: 9285664 DOI: 10.1016/s0002-9149(97)00401-3] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Interrupted aortic arch (IAA) type B is a congenital heart defect believed to be caused by an anomaly of bronchial arch mesenchymal development. IAA type B has been associated with DiGeorge syndrome (DGS), which includes conotruncal heart defects, T-cell immunodeficiency, hypocalcemia, and facial abnormalities. The great majority of DGS cases are associated with hemizygous deletions at the chromosome 22q11 locus. The present study was designed to establish the involvement of the 22q11 locus in the etiology of IAA type B, independently from the typical DGS phenotype. An evaluation was performed on 73 patients with conotruncal heart defects using fluorescence in situ hybridization (FISH) analysis with probes from the 22q11 DGS locus. From this group, 7 patients were deleted (including 4 of the 11 patients with IAA type B). FISH analysis was extended to a total of 22 patients with IAA type B and 11 of these (50%) were deleted. FISH and Southern blot analyses using additional markers within the DiGeorge chromosomal region were performed on patients found not to be deleted in the initial FISH screening. No small deletions or rearrangements were detected. In our patient population, a single, specific genetic defect is the basis for one half of the IAA type B cases. These data suggest that IAA type B is one of the most etiologically homogeneous congenital heart defects. A 22q11 deletion in IAA type B may or may not be associated with the typical DGS phenotype. Therefore, IAA type B, per se, should be an indication for 22q11 deletion testing.
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Affiliation(s)
- M B Lewin
- Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston 77030, USA
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29
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Chieffo C, Garvey N, Gong W, Roe B, Zhang G, Silver L, Emanuel BS, Budarf ML. Isolation and characterization of a gene from the DiGeorge chromosomal region homologous to the mouse Tbx1 gene. Genomics 1997; 43:267-77. [PMID: 9268629 DOI: 10.1006/geno.1997.4829] [Citation(s) in RCA: 118] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
DiGeorge syndrome, velocardiofacial syndrome, conotruncal anomaly face syndrome, and isolated and familial forms of conotruncal cardiac defects have been associated with deletions of chromosomal region 22q11.2. This report describes the identification, cloning, and characterization of the human TBX1 gene, which maps to the center of the DiGeorge chromosomal region. Further, we have extended the mouse cDNA sequence to permit comparisons between human and mouse Tbx1. TBX1 is a member of a phylogenetically conserved family of genes that share a common DNA-binding domain, the T-box. T-box genes are transcription factors involved in the regulation of developmental processes. There is 98% amino acid identity between human and mouse TBX1 proteins overall, and within the T-box domain, the proteins are identical except for two amino acids. Expression of human TBX1 in adult and fetal tissues, as determined by Northern blot analysis, is similar to that found in the mouse. Additionally, using 3 'RACE, we obtained a differentially spliced message in adult skeletal muscle. Mouse Tbx1 has been previously shown to be expressed during early embryogenesis in the pharyngeal arches, pouches, and otic vesicle. Later in development, expression is seen in the vertebral column and tooth bud. Thus, human TBX1 is a candidate for some of the features seen in the 22q11 deletion syndrome.
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Affiliation(s)
- C Chieffo
- The Children's Hospital of Philadelphia, Pennsylvania 19104, USA
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30
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Ligon AH, Beaudet AL, Shaffer LG. Simultaneous, multilocus FISH analysis for detection of microdeletions in the diagnostic evaluation of developmental delay and mental retardation. Am J Hum Genet 1997; 61:51-9. [PMID: 9245984 PMCID: PMC1715875 DOI: 10.1086/513904] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Many microdeletion and contiguous gene-deletion syndromes include mental retardation as a clinical feature. We have developed MultiFISH, a FISH assay using several probes to simultaneously screen for multiple microdeletion syndromes in patients who present with unexplained devleopmental delay and/or mental retardation. This screening tool can be used to determine whether a particular microdeletion syndrome is involved in the etiology of these clinical phenotypes. In this pilot study we combined probes for the commonly deleted regions of Prader-Willi, Angelman, Williams, Smith-Magenis, and DiGeorge/velocardiofacial syndromes in a single hybridization. The probes were differentially labeled, allowing multicolor detection, and 200 individual samples were screened in a blinded fashion. For all patients found by MultiFISH to have deletions, the deletions were originally identified and/or later confirmed by use of single-probe FISH analysis in our diagnostic cytogenetics laboratory. One patient, who was referred for developmental delay and was shown to have a normal G-banded karyotype, was identified by MultiFISH as having a micro-deletion at the DiGeorge/velocardiofacial commonly deleted region. Forty-six of the 200 total samples were tested for microdeletions by use of single FISH probes in the diagnostic laboratory. Ten of these cases were found to have deletions, and all deletions were subsequently detected by use of MultiFISH screen performed in a blinded fashion. Additionally, for all 200 patients tested by use of MultiFISH, no false-positive deletion results were observed. We demonstrate the ability of this technique to scan for and to identify microdeletions in a proportion of patients whose routine karyotype appears normal yet who are mentally retarded and/or developmentally delayed.
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Affiliation(s)
- A H Ligon
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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31
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Fokstuen S, Bottani A, Medeiros PFV, Antonarakis SE, Stoll C, Schinzel A. Laryngeal atresia type III (glottic web) with 22q11.2 microdeletion: Report of three patients. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/(sici)1096-8628(19970516)70:2<130::aid-ajmg5>3.0.co;2-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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32
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Taylor C, Wadey R, O'Donnell H, Roberts C, Mattei MG, Kimber WL, Wynshaw-Boris A, Scambler PJ. Cloning and mapping of murine Dgcr2 and its homology to the Sez-12 seizure-related protein. Mamm Genome 1997; 8:371-5. [PMID: 9107688 DOI: 10.1007/s003359900445] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- C Taylor
- Molecular Medicine Unit, Institute of Child Health, 30, Guilford St., London WC1N 1EH, UK
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33
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Collins JE, Mungall AJ, Badcock KL, Fay JM, Dunham I. The organization of the gamma-glutamyl transferase genes and other low copy repeats in human chromosome 22q11. Genome Res 1997; 7:522-31. [PMID: 9149947 DOI: 10.1101/gr.7.5.522] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A clone map consisting of YACs, cosmids, and fosmids has been constructed covering low copy repeat regions of human chromosome 22q11. A combination of clone restriction digest analysis, single-copy landmark content analysis, HindIII-Sau3AI fingerprinting, and sequencing of PCR products derived from clones was required to resolve the map in this region. Seven repeat-containing contigs were placed in 22q11, five containing gamma-glutamyl transferase (GGT) sequences described previously. In one case, a single interval at the resolution of the YAC map was shown to contain at least three GGT sequences after higher resolution mapping. The sequence information was used to design a rapid PCR/restriction digest technique that distinguishes the GGT loci placed in the YAC map. This approach has allowed us to resolve the previous cDNA and mapping information relating to GGT and link it to the physical map of 22q11.
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34
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Lachman HM, Kelsoe JR, Remick RA, Sadovnick AD, Rapaport MH, Lin M, Pazur BA, Roe AM, Saito T, Papolos DF. Linkage studies suggest a possible locus for bipolar disorder near the velo-cardio-facial syndrome region on chromosome 22. AMERICAN JOURNAL OF MEDICAL GENETICS 1997; 74:121-8. [PMID: 9129709 DOI: 10.1002/(sici)1096-8628(19970418)74:2<121::aid-ajmg2>3.0.co;2-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Velo-cardio-facial syndrome (VCFS) is a congenital anomaly characterized by multiple dysmorphisms, cleft palate, cardiac anomalies, and learning disabilities, that results from a microdeletion of chromosome 22q11. An increased prevalence of psychiatric illness has been observed, with both schizophrenia and bipolar disorder commonly being diagnosed. For these reasons, the VCFS region is an interesting candidate region for bipolar disorder. We examined this region in 17 bipolar families from three populations: 13 families from the general North American population (University of California, San Diego/University of British Columbia, UCSD/UBC), three larger families from New York, and a portion of Old Order Amish pedigree 110. Three microsatellite markers spanning 13 cM around the VCFS region were genotyped in all the families. A maximum lod score of 2.51 was obtained in the UCSD/UBC families under a dominant model at D22S303. In the combined family set, maximum lod scores of 1.68 and 1.28 were obtained at this marker under dominant and recessive models, respectively. Four additional markers were subsequently typed in selected positive families, and yielded positive lods at 6 of 7 markers spanning 18 cM in this region. Nonparametric, multipoint analyses using the affected pedigree member (APM) method also yielded suggestive evidence for linkage in both the UCSD/UBC family set (P = 0.0024) and in the combined families (P = 0.017). Affected sibpair analyses were similarly positive in the UCSD/UBC families (P = 0.017), and in the combined families (P = 0.004). These results are suggestive of a possible locus for bipolar disorder near the VCFS region on chromosome 22.
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Affiliation(s)
- H M Lachman
- Department of Psychiatry, Albert Einstein College of Medicine, Bronx, New York, USA
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35
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Sirotkin H, O'Donnell H, DasGupta R, Halford S, St Jore B, Puech A, Parimoo S, Morrow B, Skoultchi A, Weissman SM, Scambler P, Kucherlapati R. Identification of a new human catenin gene family member (ARVCF) from the region deleted in velo-cardio-facial syndrome. Genomics 1997; 41:75-83. [PMID: 9126485 DOI: 10.1006/geno.1997.4627] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Velo-cardio-facial syndrome (VCFS) and DiGeorge syndrome (DGS) are characterized by a wide spectrum of phenotypes, including conotruncal heart defects, cleft palate, and facial dysmorphology. Hemizygosity for a portion of chromosome 22q11 has been detected in 80-85% of VCFS/DGS patients. Both syndromes are thought to be the result of a developmental field defect. Using two independent gene-isolation procedures, we isolated a new catenin family member termed ARVCF (armadillo repeat gene deleted in VCFS) from the interval deleted in VCFS. ARVCF encodes a protein of 962 amino acids that contains a coiled coil domain and 10 tandem armadillo repeats. The primary structure of the protein is most closely related to the murine catenin p120CAS, which suggests a role for ARVCF in protein-protein interactions at adherens junctions. ARVCF is expressed ubiquitously in all fetal and adult tissues examined. This gene is hemizygous in all VCFS patients with interstitial deletions. Based on the physical location and potential functions of ARVCF, we suggest that hemizygosity at this locus may play a role in the etiology of some of the phenotypes associated with VCFS.
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Affiliation(s)
- H Sirotkin
- Department of Molecular Genetics, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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36
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Gong W, Emanuel BS, Galili N, Kim DH, Roe B, Driscoll DA, Budarf ML. Structural and mutational analysis of a conserved gene (DGSI) from the minimal DiGeorge syndrome critical region. Hum Mol Genet 1997; 6:267-76. [PMID: 9063747 DOI: 10.1093/hmg/6.2.267] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The majority of patients with DiGeorge syndrome (DGS), velocardiofacial syndrome (VCFS), conotruncal anomaly face syndrome (CTAFS) and some individuals with familial or sporadic conotruncal cardiac defects have hemizygous deletions of chromosome 22. Most patients with these disorders share a common large deletion, spanning > 1.5 Mb within 22q11.21-q11.23. Recently, the smallest region of deletion overlap has been narrowed to a 250 kb area, the minimal DGS critical region (MDGCR), which includes the locus D22S75 (N25). We have isolated and characterized a novel, highly conserved gene, DGSI, within the MDGCR. DGSI has 10 exons and nine introns encompassing 1702 bp of cDNA sequence and 11 kb of genomic DNA. The encoded protein has 476 amino acids with a predicted mol. wt of 52.6 kDa. The intron-exon boundaries have been analyzed and conform to the consensus GT/AG motif. The corresponding murine Dgsi has been isolated and localized to proximal mouse chromosome 16. The mouse gene contains the same number of exons and introns, and the predicted protein has 479 amino acids with 93.2% identity to that of the human DGSI gene. By database searching, both genes have significant homology to a Caenorhabditis elegans hypothetical protein, F42H10.7. Further, mutation analysis has been performed in 16 patients, who have no detectable 22q11.2 deletion and some of the characteristic clinical features of DGS/VCFS. We have detected eight sequence variants in DGSI. These occurred in the 5'-untranslated region, the coding region and the intronic regions adjacent to the intron-exon boundaries of the gene. Seven of the eight variants were also present in normal controls or unaffected family members, suggesting they may not be of etiologic significance.
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Affiliation(s)
- W Gong
- Division of Human Genetics and Molecular Biology, Children's Hospital of Philadelphia, PA, USA
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37
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Wilming LG, Snoeren CA, van Rijswijk A, Grosveld F, Meijers C. The murine homologue of HIRA, a DiGeorge syndrome candidate gene, is expressed in embryonic structures affected in human CATCH22 patients. Hum Mol Genet 1997; 6:247-58. [PMID: 9063745 DOI: 10.1093/hmg/6.2.247] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
A wide spectrum of birth defects is caused by deletions of the DiGeorge syndrome chromosomal region at 22q11. Characteristic features include cranio-facial, cardiac and thymic malformations, which are thought to arise form disturbances in the interactions between hindbrain neural crest cells and the endoderm of the pharyngeal pouches. Several genes have been identified in the shortest region of deletion overlap at 22q11, but nothing is known about the expression of these genes in mammalian embryos. We report here the isolation of several murine embryonic cDNAs of the DiGeorge syndrome candidate gene HIRA. We identified several alternatively spliced transcripts. Sequence analysis reveals that Hira bears homology to the p60 subunit of the human Chromatin Assembly Factor I and yeast hir1p and Hir2p, suggesting that Hira might have some role in chromatin assembly and/or histone regulation. Whole mount in situ hybridization of mouse embryos at various stages of development show that Hira is ubiquitously expressed. However, higher levels of transcripts are detected in the cranial neural folds, frontonasal mass, first two pharyngeal arches, circumpharyngeal neural crest and the limb buds. Since many of the structures affected in DiGeorge syndrome derive from these Hira expressing cell populations we propose that haploinsufficiency of HIRA contributes to at least some of the features of the DiGeorge phenotype.
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Affiliation(s)
- L G Wilming
- Institute of Pediatric Surgery, Erasmus University, Rotterdam, The Netherlands
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Rizzu P, Lindsay EA, Taylor C, O'Donnell H, Levy A, Scambler P, Baldini A. Cloning and comparative mapping of a gene from the commonly deleted region of DiGeorge and Velocardiofacial syndromes conserved in C. elegans. Mamm Genome 1996; 7:639-43. [PMID: 8703114 DOI: 10.1007/s003359900197] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
We have identified and cloned a gene, ES2, encoding a putative 476 amino acid protein with a predicted Mr of 52,568. The gene is localized within the DiGeorge/Velocardiofacial syndrome locus on 22q11.2 and is deleted in all the patients in which a deletion within 22q11 could be demonstrated, with the exception of one patient. ES2 is expressed in all the tissues studied. Sequence comparison showed identity with five ESTs and at the amino acid level the sequence was highly similar to, and collinear with, a hypothetical C. elegans protein of unknown function. Mutation analysis was performed in 16 patients without deletion, but no mutation has been found. The cDNA sequence is conserved in mouse and is localized on MMU16B1-B3, known to contain a syntenic group in common with HSA 22q11.2.
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Affiliation(s)
- P Rizzu
- Department of Molecular and Human Genetics, Baylor College of Medicine, 1 Baylor Plaza, T936, Houston, Texas 77030, USA
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Levy-Mozziconacci A, Lacombe D, Leheup B, Wernert F, Rouault F, Philip N. [Microdeletion of the chromosome 22q11 in children: apropos of a series of 49 patients]. Arch Pediatr 1996; 3:761-8. [PMID: 8998528 DOI: 10.1016/0929-693x(96)82157-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
UNLABELLED Most of the children with Di George syndrome and 60% of patients with velocardiofacial syndrome exhibit a microdeletion within chromosome 22q11. The phenotypic expression of this chromosomal abnormality is highly variable. PATIENTS Forty-nine children, 0 to 15 years of age, were demonstrated as carriers of a 22q11 microdeletion. The main referral diagnoses were: Di George syndrome (19 cases), velocardiofacial syndrome (14 cases); congenital heart defect with dysmorphism (9 cases); hypoparathyroidism (2 cases). The microdeletion was detected by fluorescent in situ hybridization with probes specific of the 22q11 region. RESULTS Facial dysmorphism was the only constant feature. A congenital heart defect was present in 84% of cases. Significant hypocalcemia was documented in 51% of cases and thymic hypo or agenesis in 83%. Significant immune deficiency was documented in nine cases. The most frequent associated defects were urinary tract malformations (8 cases). A cleft palate was present in height enfants but velopharyngeal insufficiency was almost constant. Two-thirds of children had psychomotor delay, and five children exhibited behavioral problems. Of the 35 couples of parents tested, eight mothers were found to be carriers of the deletion. CONCLUSION For the pediatrician, it is essential to know the variability of the clinical picture. The long-term prognosis is conditioned by the possibility of mental retardation and learning disabilities. Parents should be tested for the presence of the deletion. The occurrence of the microdeletion in asymptomatic relatives raises difficult problems in genetic counselling.
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Affiliation(s)
- A Levy-Mozziconacci
- Centre de génétique médicale et Inserm U242, hôpital d'enfants de la Timone, Marseille, France
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Daw SC, Taylor C, Kraman M, Call K, Mao J, Schuffenhauer S, Meitinger T, Lipson T, Goodship J, Scambler P. A common region of 10p deleted in DiGeorge and velocardiofacial syndromes. Nat Genet 1996; 13:458-60. [PMID: 8696341 DOI: 10.1038/ng0896-458] [Citation(s) in RCA: 164] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
DiGeorge (DGS, MIM 188400) and velocardiofacial (VCFS, MIM 192430) syndromes may present many clinical problems including cardiac defects, hypoparathyroidism, T-cell immunodeficiency and facial dysmorphism. They are frequently associated with deletions within 22q11.2, but a number of cases have no detectable molecular defect of this region. A number of single case reports with deletions of 10p suggest genetic heterogeneity of DGS. Here we compare the regions of hemizygosity in four patients with terminal deletions of 10p (one patient diagnosed as having hypoparathyroidism and three as DGS) and one patient with a large interstitial deletion (diagnosed as VCFS). Fluorescence in situ hybridization (FISH) analysis demonstrates that these patients have overlapping deletions at the 10p13/10p14 boundary. A YAC contig spanning the shortest region of deletion overlap (SRO) has been assembled, and allows the size of SRO to be approximated to 2 Mb. As with deletions of 22q11, phenotypes vary considerably between affected patients. These results strongly support the hypothesis that haploinsufficiency of a gene or genes within 10p (the DGSII locus) can cause the DGS/VCFS spectrum of malformation.
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Affiliation(s)
- S C Daw
- Molecular Medicine Unit, Institute of Child Health, London, UK
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Debrus S, Berger G, de Meeus A, Sauer U, Guillaumont S, Voisin M, Bozio A, Demczuk S, Aurias A, Bouvagnet P. Familial non-syndromic conotruncal defects are not associated with a 22q11 microdeletion. Hum Genet 1996; 97:138-44. [PMID: 8566942 DOI: 10.1007/bf02265254] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Molecular studies have shown microdeletions in region q11 of chromosome 22 in nearly all patients with DiGeorge, velocardiofacial and conotruncal anomaly face syndromes (DGS, VCFS and CTAFS, respectively) and in a high percentage of non-syndromic familial cases of conotruncal defects (CTD). CTD account for roughly a fourth to a third of all non-syndromic congenital heart defects (CHD), thus, 22q11 could harbor a major genetic factor of CHD. We searched for a 22q11 microdeletion in familial cases of non-syndromic CTD. Thirty-six cases of various isolated CTD, that is without history of hypocalcemia, immune deficiency, absent thymus, and dysmorphic appearance, were selected. With 48F8, a cosmid probe localized in the smallest deleted region of the DiGeorge critical region (DGCR), we found no deletions by fluorescence in situ hybridization in these 36 affected individuals of 16 families with recurrent CTD. Moreover, D22S264, a microsatellite localized at the distal part of the largest deleted region, was used to genotype the patients. Thirty-two patients out of 37 were heterozygous and hence not deleted at this locus, whereas 5 were uninformative. In conclusion, there are no large deletions in familial cases of various CTD, whether these defects are identical or not within a family. This result does not rule out other minor anomalies in this chromosomal region.
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Affiliation(s)
- S Debrus
- CRBM, CNRS-INSERM, Montpellier, France
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Karayiorgou M, Morris MA, Morrow B, Shprintzen RJ, Goldberg R, Borrow J, Gos A, Nestadt G, Wolyniec PS, Lasseter VK. Schizophrenia susceptibility associated with interstitial deletions of chromosome 22q11. Proc Natl Acad Sci U S A 1995; 92:7612-6. [PMID: 7644464 PMCID: PMC41195 DOI: 10.1073/pnas.92.17.7612] [Citation(s) in RCA: 473] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
We report the results of two studies examining the genetic overlap between schizophrenia and velocardiofacial syndrome. In study A, we characterize two interstitial deletions identified on chromosome 22q11 in a sample of schizophrenic patients. The size of the deletions was estimated to be between 1.5 and 2 megabases. In study B, we examine whether variations in deletion size are associated with the schizophrenic phenotype in velocardiofacial syndrome patients. Our results show that a region of the genome that has been previously implicated by genetic linkage analysis can harbor genetic lesions that increase the susceptibility to schizophrenia. Our findings should facilitate identification and cloning of the schizophrenia susceptibility gene(s) in this region and identification of more homogeneous subgroups of patients.
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Affiliation(s)
- M Karayiorgou
- Fred Hutchinson Cancer Research Center, Seattle, WA 98104, USA
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Mulder MP, Wilke M, Langeveld A, Wilming LG, Hagemeijer A, van Drunen E, Zwarthoff EC, Riegman PH, Deelen WH, van den Ouweland AM. Positional mapping of loci in the DiGeorge critical region at chromosome 22q11 using a new marker (D22S183). Hum Genet 1995; 96:133-41. [PMID: 7635459 DOI: 10.1007/bf00207368] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The majority of patients with DiGeorge syndrome (DGS) and velo-cardio-facial syndrome (VCFS) and a minority of patients with non-syndromic conotruncal heart defects are hemizygous for a region of chromosome 22q11. The chromosomal region that is commonly deleted is larger than 2 Mb. It has not been possible to narrow the smallest region of overlap (SRO) of the deletions to less than ca 500 kb, which suggests that DGS/VCFS might be a contiguous gene syndrome. The saturation cloning of the SRO is being carried out, and one gene (TUPLE1) has been identified. By using a cosmid probe (M51) and fluorescence in situ hybridization, we show here that the anonymous DNA marker locus D22S183 is within the SRO, between TUPLE1 and D22S75 (probe N25). A second locus with weak homology to D22S183, recognized by cosmid M56, lies immediately outside the common SRO of the DGS and VCFS deletions, but inside the SRO of the DGS deletions. D22S183 sequences are strongly conserved in primates and weaker hybridizing signals are found in DNA of other mammalian species; no transcripts are however detected in polyA+ RNA from various adult human organs. Probe M51 allows fast reliable screening for 22q11 deletions using fluorescence in situ hybridization. A deletion was found in 11 out of 12 DGS patients and in 3 out of 7 VCFS patients. Two patients inherited the deletion from a parent with mild (atypical) symptoms.
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Affiliation(s)
- M P Mulder
- Department of Cell Biology and Genetics, Erasmus University, Rotterdam, The Netherlands
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Lindsay EA, Goldberg R, Jurecic V, Morrow B, Carlson C, Kucherlapati RS, Shprintzen RJ, Baldini A. Velo-cardio-facial syndrome: frequency and extent of 22q11 deletions. AMERICAN JOURNAL OF MEDICAL GENETICS 1995; 57:514-22. [PMID: 7677167 DOI: 10.1002/ajmg.1320570339] [Citation(s) in RCA: 110] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Velo-cardio-facial (VCFS) or Shprintzen syndrome is associated with deletions in a region of chromosome 22q11.2 also deleted in DiGeorge anomaly and some forms of congenital heart disease. Due to the variability of phenotype, the evaluation of the incidence of deletions has been hampered by uncertainty of diagnosis. In this study, 54 patients were diagnosed with VCFS by a single group of clinicians using homogeneous clinical criteria independent of the deletion status. Cell lines of these patients were established and the deletion status evaluated for three loci within the commonly deleted region at 22q11.2 using fluorescence in situ hybridization (FISH). In 81% of the patients all three loci were hemizygous. In one patient we observed a smaller interstitial deletion than that defined by the three loci. The phenotype of this patient was not different from that observed in patients with larger deletions.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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Lindsay EA, Shaffer LG, Carrozzo R, Greenberg F, Baldini A. De novo tandem duplication of chromosome segment 22q11-q12: clinical, cytogenetic, and molecular characterization. AMERICAN JOURNAL OF MEDICAL GENETICS 1995; 56:296-9. [PMID: 7778594 DOI: 10.1002/ajmg.1320560316] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We report on a case of duplication of the segment 22q11-q12 due to a de novo duplication. Molecular cytogenetics studies demonstrated this to be a tandem duplication, flanked proximally by the marker D22Z4, a centromeric alpha satellite DNA repeat, and distally by D22S260, an anonymous DNA marker proximal to the Ewing sarcoma breakpoint. The segment includes the regions responsible for the "cat-eye," Di George, and velo-cardio-facial syndromes and extends distal to the breakpoint cluster region (BCR). The clinical picture is dominated by the cardiac defects and includes findings reminiscent of "cat-eye" syndrome. These findings reinforce the hypothesis that the proximal 22q region contains dosage-sensitive genes involved in development.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA
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Lindsay EA, Greenberg F, Shaffer LG, Shapira SK, Scambler PJ, Baldini A. Submicroscopic deletions at 22q11.2: variability of the clinical picture and delineation of a commonly deleted region. AMERICAN JOURNAL OF MEDICAL GENETICS 1995; 56:191-7. [PMID: 7625444 DOI: 10.1002/ajmg.1320560216] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
DiGeorge anomaly (DGA) and velo-cardiofacial syndrome (VCFS) are frequently associated with monosomy of chromosome region 22q11. Most patients have a submicroscopic deletion, recently estimated to be at least 1-2 Mb. It is not clear whether individuals who present with only some of the features of these conditions have the deletion, and if so, whether the size of the deletion varies from those with more classic phenotypes. We have used fluorescence in situ hybridization (FISH) to assess the deletion status of 85 individuals referred to us for molecular analysis, with a wide range of DGA-like or VCFS-like clinical features. The test probe used was the cosmid sc11.1, which detects two loci about 2 Mb apart in 22q11.2. Twenty-four patients carried the deletion. Of the deleted patients, most had classic DGA or VCFS phenotypes, but 6 deleted patients had mild phenotypes, including 2 with minor facial anomalies and velopharyngeal incompetence as the only presenting signs. Despite the great phenotypic variability among the deleted patients, none had a deletion smaller than the 2-Mb region defined by sc11.1. Smaller deletions were not detected in patients with particularly suggestive phenotypes who were not deleted for sc11.1, even when tested with two other probes from the DGA/VCFS region.
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Affiliation(s)
- E A Lindsay
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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Delaroche I, Sabani M, Calabrese G, Mingarelli R, Palka G, Dallapiccola B. Fetal translocation between chromosomes 2, 18, and 21 resolved by fish. Prenat Diagn 1995; 15:278-81. [PMID: 7784387 DOI: 10.1002/pd.1970150312] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
An apparently balanced t(2q;21q) translocation was discovered in fetal blood and amniocytes of a 22-week fetus, monitored because of ultrasonographic evidence of a heart disease. FISH (fluorescence in situ hybridization) analysis disclosed a complex translocation between chromosomes 2q, 18q, and 21q, which was inherited from the healthy mother. This observation corroborates the usefulness of molecular cytogenetic techniques in raising the quality of prenatal diagnosis and detecting subtle rearrangements not resolved by standard cytogenetics.
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MESH Headings
- Adult
- Chromosomes, Human, Pair 18
- Chromosomes, Human, Pair 2
- Chromosomes, Human, Pair 21
- Female
- Heart Defects, Congenital/diagnostic imaging
- Heart Defects, Congenital/genetics
- Humans
- In Situ Hybridization, Fluorescence
- Karyotyping
- Pregnancy
- Prenatal Diagnosis
- Translocation, Genetic
- Ultrasonography, Prenatal
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Antonacci R, Rocchi M, Archidiacono N, Baldini A. Ordered mapping of three alpha satellite DNA subsets on human chromosome 22. Chromosome Res 1995; 3:124-7. [PMID: 7749561 DOI: 10.1007/bf00710673] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We report the physical order of three alphoid DNA subsets on human chromosome 22 determined by a combination of low- and high-resolution cytological mapping. Multicolor fluorescence in situ hybridization was performed on metaphase chromosomes, interphase nuclei and extended chromatin preparations. The results visually demonstrate the presence of three distinct alphoid DNA domains at the centromeric region of chromosome 22. Two domains appear adjacent by extended chromatin hybridization, while the third one is separated by DNA that does not hybridize with any of our probes. Our data demonstrate the applicability of interphase mapping for ordering alpha satellite DNA repeat arrays. However, in our experiments, the relationship between the extremities of repeat arrays could only be studied by extended chromatin experiments.
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Affiliation(s)
- R Antonacci
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
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