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Sarac Sivrikoz T, Basaran S, Has R, Karaman B, Kalelioglu IH, Kirgiz M, Altunoglu U, Yuksel A. Prenatal sonographic and cytogenetic/molecular findings of 22q11.2 microdeletion syndrome in 48 confirmed cases in a single tertiary center. Arch Gynecol Obstet 2021; 305:323-342. [PMID: 34145474 DOI: 10.1007/s00404-021-06125-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/12/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE We aimed to present the fetal ultrasound, cytogenetic/molecular testing and postmortem or postnatal clinical findings of cases with 22q11.2DS diagnosed prenatally. MATERIALS AND METHODS A retrospective medical record review of 48 prenatal cases diagnosed with 22q11.2DS were evaluated in our institution. Detailed ultrasound examination was performed on all fetuses. Postmortem and postnatal examinations were evaluated. The microdeletions were detected by karyotyping or microarray, then confirmed by FISH. Descriptive statistical analysis was performed. RESULTS Demographic data of 48 prenatal cases including 46 singletons and 1 dichorionic diamniotic twin pregnancy were evaluated. The most common extracardiac anomaly was skeletal system anomalies (25%), in which PEV was the most frequent one (20.8%). Polyhydramnios rate was detected as 31%, in 6.6% as an isolated finding. Microdeletion has been detected by karyotyping in 13 cases (13/47, 27.7%) (including 2 unbalanced translocations), by FISH in 28 cases (28/48, 58.3%), by microarray/a-CGH testing in 7 cases. Microarray analysis showed that in one case with unbalanced translocation had two consecutive deletions; one was proximal and other one distal to critical region and not encompassing TBX1 gene but CRKL and LZTR1 genes. CONCLUSION The current study demonstrates the whole spectrum of atypical phenotypic and genotypic variations of 22q11.2DS in the largest prenatal case series reported to date. Therefore, differential diagnosis should be considered not solely in CHD, but also in the presence of isolated clubfeet and polyhydramnios. Establishing the diagnosis in the prenatal period may allow a postnatal multidisciplinary approach, as well as affect the actual prevalence of the disease.
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Affiliation(s)
- Tugba Sarac Sivrikoz
- Division of Perinatology, Department of Obstetrics and Gynecology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey.
| | - Seher Basaran
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
- PREMED, Center for Genetic Diagnosis and Research, Mecidiyekoy, Istanbul, Turkey
| | - Recep Has
- Division of Perinatology, Department of Obstetrics and Gynecology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Birsen Karaman
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
- Department of Pediatric Basic Science, Child Health Institute, Istanbul University, Istanbul, Turkey
| | - Ibrahim Halil Kalelioglu
- Division of Perinatology, Department of Obstetrics and Gynecology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Melike Kirgiz
- PREMED, Center for Genetic Diagnosis and Research, Mecidiyekoy, Istanbul, Turkey
| | - Umut Altunoglu
- Department of Medical Genetics, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Atil Yuksel
- Division of Perinatology, Department of Obstetrics and Gynecology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
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Morrow BE, McDonald-McGinn DM, Emanuel BS, Vermeesch JR, Scambler PJ. Molecular genetics of 22q11.2 deletion syndrome. Am J Med Genet A 2019; 176:2070-2081. [PMID: 30380194 DOI: 10.1002/ajmg.a.40504] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 06/11/2018] [Accepted: 07/17/2018] [Indexed: 02/02/2023]
Abstract
The 22q11.2 deletion syndrome (22q11.2DS) is a congenital malformation and neuropsychiatric disorder caused by meiotic chromosome rearrangements. One of the goals of this review is to summarize the current state of basic research studies of 22q11.2DS. It highlights efforts to understand the mechanisms responsible for the 22q11.2 deletion that occurs in meiosis. This mechanism involves the four sets of low copy repeats (LCR22) that are dispersed in the 22q11.2 region and the deletion is mediated by nonallelic homologous recombination events. This review also highlights selected genes mapping to the 22q11.2 region that may contribute to the typical clinical findings associated with the disorder and explain that mutations in genes on the remaining allele can uncover rare recessive conditions. Another important aspect of 22q11.2DS is the existence of phenotypic heterogeneity. While some patients are mildly affected, others have severe medical, cognitive, and/or psychiatric challenges. Variability may be due in part to the presence of genetic modifiers. This review discusses current genome-wide efforts to identify such modifiers that could shed light on molecular pathways required for normal human development, cognition or behavior.
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Affiliation(s)
- Bernice E Morrow
- Department of Genetics, Albert Einstein College of Medicine, Bronx, New York
| | - Donna M McDonald-McGinn
- Division of Human Genetics, Children's Hospital of Philadelphia and Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Beverly S Emanuel
- Division of Human Genetics, Children's Hospital of Philadelphia and Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Joris R Vermeesch
- Center for Human Genetics, Katholieke Universiteit Leuven (KU Leuven), Leuven, Belgium
| | - Peter J Scambler
- Institute of Child Health, University College London, London, UK
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Sellier C, Hwang VJ, Dandekar R, Durbin-Johnson B, Charlet-Berguerand N, Ander BP, Sharp FR, Angkustsiri K, Simon TJ, Tassone F. Decreased DGCR8 expression and miRNA dysregulation in individuals with 22q11.2 deletion syndrome. PLoS One 2014; 9:e103884. [PMID: 25084529 PMCID: PMC4118991 DOI: 10.1371/journal.pone.0103884] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 07/08/2014] [Indexed: 11/30/2022] Open
Abstract
Deletion of the 1.5–3 Mb region of chromosome 22 at locus 11.2 gives rise to the chromosome 22q11.2 deletion syndrome (22q11DS), also known as DiGeorge and Velocardiofacial Syndromes. It is the most common micro-deletion disorder in humans and one of the most common multiple malformation syndromes. The syndrome is characterized by a broad phenotype, whose characterization has expanded considerably within the last decade and includes many associated findings such as craniofacial anomalies (40%), conotruncal defects of the heart (CHD; 70–80%), hypocalcemia (20–60%), and a range of neurocognitive anomalies with high risk of schizophrenia, all with a broad phenotypic variability. These phenotypic features are believed to be the result of a change in the copy number or dosage of the genes located in the deleted region. Despite this relatively clear genetic etiology, very little is known about which genes modulate phenotypic variations in humans or if they are due to combinatorial effects of reduced dosage of multiple genes acting in concert. Here, we report on decreased expression levels of genes within the deletion region of chromosome 22, including DGCR8, in peripheral leukocytes derived from individuals with 22q11DS compared to healthy controls. Furthermore, we found dysregulated miRNA expression in individuals with 22q11DS, including miR-150, miR-194 and miR-185. We postulate this to be related to DGCR8 haploinsufficiency as DGCR8 regulates miRNA biogenesis. Importantly we demonstrate that the level of some miRNAs correlates with brain measures, CHD and thyroid abnormalities, suggesting that the dysregulated miRNAs may contribute to these phenotypes and/or represent relevant blood biomarkers of the disease in individuals with 22q11DS.
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Affiliation(s)
- Chantal Sellier
- Institute of Genetics and Molecular and Cellular Biology, University of Strasbourg, Strasbourg, France
| | - Vicki J. Hwang
- Department of Biochemistry and Molecular Medicine, University of California Davis, Sacramento, California, United States of America
| | - Ravi Dandekar
- Department of Biochemistry and Molecular Medicine, University of California Davis, Sacramento, California, United States of America
| | - Blythe Durbin-Johnson
- Department of Public Health Sciences, UC Davis Medical Center, Sacramento, California, United States of America
| | | | - Bradley P. Ander
- MIND Institute, UC Davis Medical Center, Sacramento, California, United States of America
- Department of Neurology, UC Davis Medical Center, Sacramento, California, United States of America
| | - Frank R. Sharp
- MIND Institute, UC Davis Medical Center, Sacramento, California, United States of America
- Department of Neurology, UC Davis Medical Center, Sacramento, California, United States of America
| | - Kathleen Angkustsiri
- MIND Institute, UC Davis Medical Center, Sacramento, California, United States of America
- Department of Pediatrics, UC Davis Medical Center, Sacramento, California, United States of America
| | - Tony J. Simon
- MIND Institute, UC Davis Medical Center, Sacramento, California, United States of America
- Department of Psychiatry, UC Davis Medical Center, Sacramento, California, United States of America
| | - Flora Tassone
- Department of Biochemistry and Molecular Medicine, University of California Davis, Sacramento, California, United States of America
- MIND Institute, UC Davis Medical Center, Sacramento, California, United States of America
- * E-mail:
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Rio M, Royer G, Gobin S, de Blois MC, Ozilou C, Bernheim A, Nizon M, Munnich A, Bonnefont JP, Romana S, Vekemans M, Turleau C, Malan V. Monozygotic twins discordant for submicroscopic chromosomal anomalies in 2p25.3 region detected by array CGH. Clin Genet 2012; 84:31-6. [PMID: 23061379 DOI: 10.1111/cge.12036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 10/04/2012] [Accepted: 10/05/2012] [Indexed: 02/06/2023]
Abstract
Although discordant phenotypes in monozygotic twins with developmental disorder are not an exception, underlying genetic discordance is rarely reported. Here, we report on the clinical and cytogenetic details of 4-year-old female monozygotic twins with discordant phenotypes. Twin 1 exhibited global developmental delay, overweight and hyperactivity. Twin 2 had an autistic spectrum disorder. Molecular karyotyping in twin 1 identified a 2p25.3 deletion, further confirmed by Fluorescence in situ hybridization (FISH) analysis on leukocytes. Interestingly, array comparative genomic hybridization was normal in twin 2 but FISH analysis using the same probe as twin 1 showed mosaicism with one-third of cells with a 2p25.3 deletion, one-third of cells with a 2p25.3 duplication, and one-third of normal cells. Genotyping with microsatellite markers confirmed the monozygosity of the twins. We propose that the chromosome imbalance may be due to a mitotic non-allelic recombination occurring during blastomeric divisions of a normal zygote. Such event will result in three distinct cell populations, whose proportion in each embryo formed after separation from the zygote may differ, leading to discordant chromosomal anomalies between twins. We also discuss that the MYTL1L and the SNTG2 genes within the reported region could probably relate to the phenotypic discordance of the monozygotic twins.
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Affiliation(s)
- M Rio
- Département de Génétique, Université Paris Descartes, Hôpital Necker-Enfants Malades, AP-HP, Paris, France
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Halder A, Jain M, Chaudhary I, Varma B. Chromosome 22q11.2 microdeletion in monozygotic twins with discordant phenotype and deletion size. Mol Cytogenet 2012; 5:13. [PMID: 22413934 PMCID: PMC3325853 DOI: 10.1186/1755-8166-5-13] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 03/13/2012] [Indexed: 02/01/2023] Open
Abstract
We report on a pair of male monozygotic twins with 22q11.2 microdeletion, discordant phenotype and discordant deletion size. The second twin had findings suggestive of DiGeorge syndrome, while the first twin had milder anomalies without any cardiac malformation. The second twin had presented with intractable convulsion, cyanosis and cardiovascular failure in the fourth week of life and expired on the sixth week of life, whereas the first twin had some characteristic facial appearance with developmental delay but no other signs of the 22q11.2 microdeletion syndrome including cardiovascular malformation. The fluorescence in situ hybridization (FISH) analysis had shown a microdeletion on the chromosome 22q11.2 in both twins. The interphase FISH did not find any evidence for the mosaicism. The genomic DNA microarray analysis, using HumanCytoSNP-12 BeadChip (Illumina), was identical between the twins except different size of deletion of 22q11.2. The zygosity using HumanCytoSNP-12 BeadChip (Illumina) microarray analysis suggested monozygosity. This observation indicates that altered size of the deletion may be the underlying etiology for the discordance in phenotype in monozygotic twins. We think early post zygotic events (mitotic non-allelic homologous recombination) could have been played a role in the alteration of 22q11.2 deletion size and, thus phenotypic variability in the monozygotic twins.
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Affiliation(s)
- Ashutosh Halder
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Manish Jain
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Isha Chaudhary
- Department of Reproductive Biology, All India Institute of Medical Sciences, New Delhi, India
| | - Binuja Varma
- The Centre for Genomic Application, 254 Okhla Industrial Area Phase III, New Delhi, India
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Zwijnenburg PJG, Meijers-Heijboer H, Boomsma DI. Identical but not the same: the value of discordant monozygotic twins in genetic research. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:1134-49. [PMID: 20468073 DOI: 10.1002/ajmg.b.31091] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Monozygotic (MZ) twins show remarkable resemblance in many aspects of behavior, health, and disease. Until recently, MZ twins were usually called "genetically identical"; however, evidence for genetic and epigenetic differences within rare MZ twin pairs has accumulated. Here, we summarize the literature on MZ twins discordant for Mendelian inherited disorders and chromosomal abnormalities. A systematic literature search for English articles on discordant MZ twin pairs was performed in Web of Science and PubMed. A total number of 2,016 publications were retrieved and reviewed and 439 reports were retained. Discordant MZ twin pairs are informative in respect to variability of phenotypic expression, pathogenetic mechanisms, epigenetics, and post-zygotic mutagenesis and may serve as a model for research on genetic defects. The analysis of single discordant MZ twin pairs may represent an elegant approach to identify genes in inherited disorders.
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Affiliation(s)
- Petra J G Zwijnenburg
- Department of Clinical Genetics, VU University Medical Center, de Boelelaan 1117, Amsterdam, the Netherlands.
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Machin G. Non-identical monozygotic twins, intermediate twin types, zygosity testing, and the non-random nature of monozygotic twinning: A review. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2009; 151C:110-27. [DOI: 10.1002/ajmg.c.30212] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Sivertsen A, Lie RT, Wilcox AJ, Abyholm F, Vindenes H, Haukanes BI, Houge G. Prevalence of duplications and deletions of the 22q11 DiGeorge syndrome region in a population-based sample of infants with cleft palate. Am J Med Genet A 2007; 143A:129-34. [PMID: 17163526 DOI: 10.1002/ajmg.a.31445] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The prevalence of duplications and deletions of the 22q11.2 (DiGeorge syndrome) region was studied among babies born in Norway with open cleft palate without cleft lip (cleft palate only, CPO). During a 5-year period (1996-2001), there were 245 live births with CPO that were referred for surgery. DNA was available from 174 cases with overt cleft palate. DNA copy number was analyzed with the multiplex ligation-dependent probe amplification (MLPA) technique, and an unambiguous result was obtained in 169 (97%) of the samples. We found no 22q11.2 duplications, and one known, and two previously undiagnosed cases with 22q11.2 deletions. All three del22q11-syndrome cases also had heart malformations, which represent one-third of the 10 babies with heart malformations in our study population. The prevalence of del22q11-syndrome among babies with cleft palate with or without additional malformations was 1 of 57 (1.8%). Because the prevalence of CPO in the 35 22q11.2 duplication cases published was 20%, we also investigated if dup22q11-testing was warranted in this group. However, no 22q11.2 duplications were found, indicating that the duplication cases ascertained so far might not be representative of the dup22q11-group as a whole. We conclude that neither del22q11 nor dup22q11 testing is warranted in babies with overt cleft palate as the only finding.
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Affiliation(s)
- Ase Sivertsen
- Department of Public Health and Primary Health Care, University of Bergen, Bergen, Norway.
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Rauch A, Hofbeck M, Cesnjevar R, Koch A, Rauch R, Buheitel G, Singer H, Weyand M. Search for somatic 22q11.2 deletions in patients with conotruncal heart defects. Am J Med Genet A 2004; 124A:165-9. [PMID: 14699615 DOI: 10.1002/ajmg.a.20323] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A wide range of clinical variability in patients with 22q11.2 deletions has been demonstrated in numerous studies. Nevertheless, it is still an open question if major genetic factors contribute to clinical expression. Therefore one aim of this study was to investigate, if patients with 22q11.2 deletion and conotruncal heart defects show a "second hit" somatic 22q11.2 deletion in tissue from the conotruncus, heart vessels or thymus. The second aim was to analyse patients with conotruncal heart defects without 22q11.2 deletion in blood cells for somatic deletion mosaicism. We were able to study tissue samples from heart surgery from 23 patients, 9 of whom had 22q11 deletions by FISH analysis on metaphase spreads from peripheral lymphocytes. Analysis of 18 polymorphic markers from the 22q11.2 region in DNA prepared from thymus and/or heart vessels and/or conotruncus tissue and peripheral lymphocytes in each patient did not show any allelic loss. Thus somatic 22q11.2 deletions apparently do not play a major role in conotruncal heart defects in patients with or without germ line 22q11.2 deletion.
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Affiliation(s)
- Anita Rauch
- Institute of Human Genetics, Friedrich-Alexander University, Erlangen-Nuremberg, Germany.
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Vitelli F, Lindsay EA, Baldini A. Genetic dissection of the DiGeorge syndrome phenotype. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 67:327-32. [PMID: 12858556 DOI: 10.1101/sqb.2002.67.327] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- F Vitelli
- Department of Pediatrics (Cardiology), Baylor College of Medicine, Houston, Texas 77030, USA
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Angle B, Yen F, Hersh JH, Gowans G, Barch M. Partial duplication 4q and deletion 1p36 in monozygotic twins with discordant phenotypes. AMERICAN JOURNAL OF MEDICAL GENETICS 2002; 111:307-12. [PMID: 12210328 DOI: 10.1002/ajmg.10599] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We report on monozygotic (MZ) twins with a de novo chromosome abnormality consisting of a partial duplication of chromosome 4 (q25-qter) and deletion of chromosome 1p36. These infants had dysmorphic facial features and other clinical manifestations similar to those described with the previously delineated duplication 4q and deletion 1p36 phenotypes and two other reported cases of combined partial duplication 4q and deletion 1p36. However, the twins were discordant for a number of congenital anomalies. The discordant phenotypes described in these genetically identical infants demonstrate that nongenetic factors may play a significant role in the phenotypic differences in patients with recognized chromosome duplication and deletion syndromes, which are usually attributed to the individual genotypic differences in the duplicated and/or deleted chromosome segments.
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Affiliation(s)
- Brad Angle
- Weisskopf Center for the Evaluation of Children, Department of Pediatrics, University of Louisville, Louisville, Kentucky 40202, USA.
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Bassett AS, Chow EW, Waterworth DM, Brzustowicz L. Genetic insights into schizophrenia. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2001; 46:131-7. [PMID: 11280081 PMCID: PMC3188301 DOI: 10.1177/070674370104600203] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To outline new insights into the genetic etiology of schizophrenia. METHODS We discuss several commonly held beliefs about the genetic issues in schizophrenia. RESULTS The complex genetic nature of the illness poses a challenge for investigators seeking causative genetic mutations. Multiple independent research findings are, however converging to identify a relatively small number of chromosomal locations that appear to contain schizophrenia susceptibility genes. Also, a clinically relevant genetic subtype of schizophrenia (22qDS) has been identified. We are developing a better understanding of how schizophrenia relates to other psychiatric disorders. While investigations into the possible roles of dopaminergic and serotonergic systems continue, other approaches that do not require theories of the mechanism of illness are also being used to identify candidate susceptibility genes. CONCLUSIONS Research to date suggests that our understanding of the pathophysiology of schizophrenia will soon be fundamentally altered by genetic approaches to this complex disease.
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Affiliation(s)
- A S Bassett
- Department of Psychiatry, University of Toronto, Ontario.
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Hodgkinson KA, Murphy J, O'Neill S, Brzustowicz L, Bassett AS. Genetic counselling for schizophrenia in the era of molecular genetics. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2001; 46:123-30. [PMID: 11280080 PMCID: PMC3276586 DOI: 10.1177/070674370104600202] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVE To review the role of genetic counselling for individuals with psychiatric illnesses. METHOD Using schizophrenia as an example and including updated information about a genetic subtype (22q deletion syndrome), we discuss the value of the genetic counselling process in psychiatry, with support from the literature and our clinical experience. RESULTS Genetic counselling, the process through which knowledge about the genetics of illnesses is shared, provides information on the inheritance of illnesses and their recurrence risks; addresses the concerns of patients, their families, and their health care providers; and supports patients and their families dealing with these illnesses. For comprehensive medical management, this service should be available to all individuals with schizophrenia and their families. CONCLUSIONS New findings in the genetics of psychiatric illness may have important clinical implications for patients and their families.
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Affiliation(s)
- K A Hodgkinson
- Genetics Department, Memorial University of Newfoundland, St John's, Newfoundland
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Hokanson JS, Pierpont E, Hirsch B, Moller JH. 22q11.2 microdeletions in adults with familial tetralogy of Fallot. Genet Med 2001; 3:61-4. [PMID: 11339381 DOI: 10.1097/00125817-200101000-00013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE To determine the incidence of 22q11.2 microdeletions in the adult survivors of correction of tetralogy of Fallot who have familial congenital heart disease. METHODS Patients who had survived a correction of tetralogy of Fallot between 1954 and 1974 and had affected family members were identified during a study of these long-term survivors. Fluorescence in situ hybridization analysis was performed using both the N 25 (Oncor) and TUPLE1(VYSIS) probes, mapped to 22q11.2. RESULTS One of 18 (5.6%) patients had a microdeletion within 22q11.2, including both N25 and TUPLE1. CONCLUSION 22q11.2 microdeletions involving TUPLE1 and/or N25 are present in a minority of adults with familial tetralogy of Fallot.
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Affiliation(s)
- J S Hokanson
- Children's Hospital of Illinois and University of Illinois College of Medicine at Peoria, USA
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Sánchez-Ramón S, Bartolomé J, Sánchez-Luna M, Franco ML, Orera M, Fernández-Cruz E, Fernández-Pacheco RP, Gil J. Polydactyly in 22q11 syndrome: should it be taken into account? Clin Genet 2000; 58:84-5. [PMID: 10945670 DOI: 10.1034/j.1399-0004.2000.580117.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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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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Abstract
Schizophrenia is likely to be caused by several susceptibility genes and may have environmental factors that interact with susceptibility genes and/or nongenetic causes. Recent evidence supports the likelihood that 22q11 Deletion Syndrome (22qDS) represents an identifiable genetic subtype of schizophrenia. 22qDS is an under-recognized genetic syndrome associated with microdeletions on chromosome 22 and a variable expression that often includes mild congenital dysmorphic features, hypernasal speech, and learning difficulties. Initial evidence indicates that a minority of patients with schizophrenia (approximately 2%) may have 22qDS and that prevalence may be somewhat higher in subpopulations with developmental delay. This paper proposes clinical criteria (including facial features, learning disabilities, hypernasal speech, congenital heart defects and other congenital anomalies) to aid in identifying patients with schizophrenia who may have this subtype and outlines features that may increase the index of suspicion for this syndrome. Although no specific causal gene or genes have yet been identified in the deletion region, 22qDS may represent a more homogeneous subtype of schizophrenia. This subtype may serve as a model for neurodevelopmental origins of schizophrenia that could aid in delineating etiologic and pathogenetic mechanisms.
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Affiliation(s)
- A S Bassett
- Schizophrenia Research Program, Centre for Addiction & Mental Health, Queen Street Division, Toronto, Ontario, Canada
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Waddington JL, Buckley PF, Scully PJ, Lane A, O'Callaghan E, Larkin C. Course of psychopathology, cognition and neurobiological abnormality in schizophrenia: developmental origins and amelioration by antipsychotics? J Psychiatr Res 1998; 32:179-89. [PMID: 9793871 DOI: 10.1016/s0022-3956(97)00012-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
It is argued that schizophrenia has origins in events occurring during the first or early second trimester that are reflected in minor physical anomalies and which may at least in part predispose to later obstetric complications. This neurodevelopmental basis underlies certain neuromotor and psychosocial abnormalities of infancy and childhood, which are the early manifestations of what will be reconceptualised later as negative symptoms and (particularly frontal) cognitive dysfunction, but gives rise to positive symptoms only on the maturation of other systems necessary for their expression. This later emergence of psychosis may reflect an active morbid process that is associated with increased accrual of negative symptoms and of general (but not frontal) cognitive impairment that may be ameliorated by effective antipsychotic treatment. The psychological or biological basis of this heuristic process is poorly understood. Contemporary re-appraisal of any impact of antipsychotics on the long-term course of schizophrenia must take into account what is known of the origins of the disease process with which such drugs might interact. Much recent work continues to indicate that very early events, during the embryonic/fetal period, are important in, if not fundamental to, the genesis of schizophrenia; i.e. that there is a neurodevelopmental basis to the disorder. The present article seeks to establish a time-line relating early intrauterine adversity and dysmorphogenesis, through the onset of psychosis, to the chronic phase of the illness over adulthood; from this time-line, a schema is elaborated for a beneficial impact of antipsychotics on the course of psychopathology, cognition and, less clearly, neurobiological abnormality.
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Affiliation(s)
- J L Waddington
- Department of Clinical Pharmacology, Royal College of Surgeons, Dublin, Ireland
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Rauch A, Hofbeck M, B�hring S, Leipold G, Trautmann U, Singer H, Pfeiffer R. Monozygotic twins concordant for Cayler syndrome. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1096-8628(19980106)75:1<113::aid-ajmg23>3.0.co;2-o] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Dallapiccola B, Pizzuti A, Novelli G. How many breaks do we need to CATCH on 22q11? Am J Hum Genet 1996; 59:7-11. [PMID: 8659546 PMCID: PMC1915098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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