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Chromosome 20p Partial De Novo Duplication Identified in a Female Paediatric Patient with Characteristic Facial Dysmorphism and Behavioural Anomalies. Case Rep Genet 2020; 2020:7093409. [PMID: 32733715 PMCID: PMC7369683 DOI: 10.1155/2020/7093409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/02/2019] [Accepted: 02/29/2020] [Indexed: 11/23/2022] Open
Abstract
Copy number variations (CNVs) involving the JAG1 gene are rare and infrequently reported in the scientific literature. Recently, a generally healthy young patient presenting with a history of behavioural concerns was referred to us. Herein, we discuss the patient, a 7-year-old female possessing a 0.797 Mb microduplication within the short arm of chromosome 20 at band 12.2. The patient generates considerable curiosity due to the rarity of her case, which includes a de novo partial duplication involving the JAG1 gene. The patient exhibits a wide range of symptoms including facial dysmorphism (dolichocephaly, round face, tented philtrum, anteverted nares, and micrognathia), clinodactyly, and an inborn congenital heart defect. She presented with behavioural concerns including ADHD-I, SPD, motor clumsiness, and poor self-regulation. Deletions in JAG1 are often linked to Alagille Syndrome; however, complete duplications have not been specifically identified as disease-causing. JAG1 mutations are reported alongside various clinical features including facial dysmorphology, heart defects, vertebral abnormalities, and ocular dysmorphic features (strabismus, epicanthal folds, and slanted palpebral fissures). This particular microduplication is rare, and thus, limited data exist regarding its significance. To our knowledge, most reported duplications are larger than 0.797 Mb. This may define a critical region causing phenotypical changes in some patient cases.
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Mansoori Derakhshan S, Shekari Khaniani M. Cytogenetic findings in patients with intellectual disability and/or multiple congenital anomalies. JOURNAL OF ANALYTICAL RESEARCH IN CLINICAL MEDICINE 2016. [DOI: 10.15171/jarcm.2016.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Multiplex ligation-dependent probe amplification to subtelomeric rearrangements in idiopathic intellectual disability in Colombia. Pediatr Neurol 2014; 50:250-4. [PMID: 24412240 DOI: 10.1016/j.pediatrneurol.2013.10.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 10/06/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND A cause cannot be determined in 30% to 50% of patients with intellectual disability. Determining the etiology of intellectual disability is important and useful for pediatric neurologists, geneticists, pediatricians, and patients' families because it allows assessment of recurrence risk, appropriate genetic counseling, and focus on treatment options and prognosis. This study aims to determine the prevalence, origin, and characterization of subtelomeric rearrangements through the Multiplex Ligation-Dependent Probe Amplification method in pediatric patients with idiopathic intellectual disability. METHODS A cross-sectional descriptive study was undertaken with patients seen in consultation at the neuropediatrics or genetic service of the Central Military Hospital, the Mercy' Hospital, or the Genetics Institute National University of Colombia. Patients were diagnosed with idiopathic intellectual disability between December 2010 and September 2011 and underwent a complete medical history, physical examination, and assessment to rule out other etiologies of intellectual disability. Then we applied the genetic test of Multiplex Ligation-Dependent Probe Amplification to each patient's sample of peripheral blood to determine subtelomeric rearrangements. RESULTS We studied a group of 119 patients with idiopathic intellectual disability; Multiplex Ligation-Dependent Probe Amplification showed subtelomeric rearrangements in five. In the group with subtelomeric rearrangements, the most frequent results were de novo rearrangements (80%), deletion type (60%), moderate and severe intellectual disability (80%), minor phenotypic abnormalities (80%), and family history of neurological disorders (80%). No dependence relationship was observed between subtelomeric rearrangements and family history of neurological disorders, family history of intellectual disability, severity of intellectual disability, phenotypic abnormalities, and consanguinity. CONCLUSIONS This study determined a prevalence of subtelomeric rearrangements of 4.2% in a group of Colombian pediatric patients with idiopathic intellectual disability using the genetic test Multiplex Ligation-Dependent Probe Amplification.
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Abstract
We conducted a cytogenetic study on 865 individuals with idiopathic mental retardation (MR) who were admitted to the Cytogenetics Department of the Iran Blood Transfusion Organisation (IBTO) Research Centre, Tehran, Iran; these were performed on blood samples using conventional staining methods. Chromosome anomalies were identified in 205 of the patients (23.6%). The majority were Down's syndrome cases (n = 138). In 33 males, a positive fragile X anomaly was found. The remainder (n = 34) had other chromosomal abnormalities including structural chromosome aberrations (n = 23), marker chromosomes with an unknown origin (n = 3), sex chromosome aneuploidy (n = 6) and trisomy 18 (n = 2). The contribution of chromosome aberrations to the cause of MR in this group of patients is discussed.
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Lee JY, Cho YH, Hallford G. Delineation of subtelomeric deletion of the long arm of chromosome 6. Ann Hum Genet 2011; 75:755-64. [PMID: 21950800 DOI: 10.1111/j.1469-1809.2011.00675.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Pure subtelomeric deletion of the long arm of chromosome 6 is rare. The frequency of this deletion accounts for approximately 0.05% of subjects with intellectual disability and developmental delay with or without dysmorphic features. Common phenotypes associated with this deletion include intellectual disability, developmental delay, dysmorphic features, seizure, hypotonia, microcephaly and hypoplasia of the corpus callosum. The smallest overlapped region is approximately 0.4 Mb, and contains three known genes. Of these genes, TBP has been considered as a plausible candidate gene for the phenotype in patients with a subtelomeric 6q deletion. Analysis of the breakpoints in 14 cases revealed a potential common breakpoint interval 8.0-9.0 Mb from the chromosome 6q terminus where the FRA6E fragile site exists and the PARK2 gene is located. This suggests that breakage at the FRA6E fragile site may be the mechanism behind chromosome 6q subtelomeric deletion in some of the cases.
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Affiliation(s)
- Ji-Yun Lee
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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Verdú Pérez A, García Murillo PL, García Campos O, López Grondona F, Arriola Pereda G, Alcaraz Rousselet MA, Vicente Lago Y, Suela J. [Subtelomeric rearrangements in cryptogenic mental retardation]. An Pediatr (Barc) 2011; 75:365-71. [PMID: 21798831 DOI: 10.1016/j.anpedi.2011.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 05/31/2011] [Accepted: 06/02/2011] [Indexed: 12/08/2022] Open
Abstract
INTRODUCTION Mental retardation affects 3% of the population, the origin of which cannot be established in 50% of cases. Subtelomeric rearrangements, not detected by routine cytogenetic studies, might explain some cases of unknown cause. PATIENTS AND METHODS A study was conducted on 200 subjects with unexplained mental retardations using multiplex ligation dependent probe amplification (MLPA). Abnormal findings were confirmed by fluorescent in situ hybridization (FISH) and/or comparative genomic hybridization technology (CGH-array). RESULTS A subtelomeric aberration was identified in 9 patients. Eight were «de novo»; one was inherited from a phenotypically normal parent. There was a statistically significant association with the presence of more than one dysmorphic feature or with intrauterine growth retardation, but not with the severity of retardation or epilepsy. CONCLUSIONS Subtelomeric rearrangements explained 4.5% of cases of mental retardation in our series. The presence of more than one dysmorphic feature or intrauterine uterine growth retardation increases the probability of this type of chromosomal aberration.
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Affiliation(s)
- A Verdú Pérez
- Unidad de Neurología Pediátrica, Hospital Virgen de la Salud, Toledo, España.
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Ingason A, Rujescu D, Cichon S, Sigurdsson E, Sigmundsson T, Pietiläinen OPH, Buizer-Voskamp JE, Strengman E, Francks C, Muglia P, Gylfason A, Gustafsson O, Olason PI, Steinberg S, Hansen T, Jakobsen KD, Rasmussen HB, Giegling I, Möller HJ, Hartmann A, Crombie C, Fraser G, Walker N, Lonnqvist J, Suvisaari J, Tuulio-Henriksson A, Bramon E, Kiemeney LA, Franke B, Murray R, Vassos E, Toulopoulou T, Mühleisen TW, Tosato S, Ruggeri M, Djurovic S, Andreassen OA, Zhang Z, Werge T, Ophoff RA, Rietschel M, Nöthen MM, Petursson H, Stefansson H, Peltonen L, Collier D, Stefansson K, St Clair DM. Copy number variations of chromosome 16p13.1 region associated with schizophrenia. Mol Psychiatry 2011; 16:17-25. [PMID: 19786961 PMCID: PMC3330746 DOI: 10.1038/mp.2009.101] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 08/18/2009] [Accepted: 08/21/2009] [Indexed: 01/22/2023]
Abstract
Deletions and reciprocal duplications of the chromosome 16p13.1 region have recently been reported in several cases of autism and mental retardation (MR). As genomic copy number variants found in these two disorders may also associate with schizophrenia, we examined 4345 schizophrenia patients and 35,079 controls from 8 European populations for duplications and deletions at the 16p13.1 locus, using microarray data. We found a threefold excess of duplications and deletions in schizophrenia cases compared with controls, with duplications present in 0.30% of cases versus 0.09% of controls (P=0.007) and deletions in 0.12 % of cases and 0.04% of controls (P>0.05). The region can be divided into three intervals defined by flanking low copy repeats. Duplications spanning intervals I and II showed the most significant (P = 0.00010) association with schizophrenia. The age of onset in duplication and deletion carriers among cases ranged from 12 to 35 years, and the majority were males with a family history of psychiatric disorders. In a single Icelandic family, a duplication spanning intervals I and II was present in two cases of schizophrenia, and individual cases of alcoholism, attention deficit hyperactivity disorder and dyslexia. Candidate genes in the region include NTAN1 and NDE1. We conclude that duplications and perhaps also deletions of chromosome 16p13.1, previously reported to be associated with autism and MR, also confer risk of schizophrenia.
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Affiliation(s)
- A Ingason
- deCODE genetics, Reykjavík, Iceland
- Research Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark
| | - D Rujescu
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University and Genetics Research Centre GmbH, Munich, Germany
| | - S Cichon
- Department of Genomics, Life & Brain Center, University of Bonn, Bonn, Germany
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - E Sigurdsson
- Department of Psychiatry, National University Hospital, Reykjavík, Iceland
| | - T Sigmundsson
- Department of Psychiatry, National University Hospital, Reykjavík, Iceland
| | - OPH Pietiläinen
- Department for Molecular Medicine, National Public Health Institute, Helsinki, Finland
| | - JE Buizer-Voskamp
- Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- Department of Medical Genetics and Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - E Strengman
- Department of Medical Genetics and Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
| | - C Francks
- Medical Genetics, GlaxoSmithKline R&D, Verona, Italy
| | - P Muglia
- Medical Genetics, GlaxoSmithKline R&D, Verona, Italy
| | | | | | | | | | - T Hansen
- Research Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark
| | - KD Jakobsen
- Research Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark
| | - HB Rasmussen
- Research Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark
| | - I Giegling
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University and Genetics Research Centre GmbH, Munich, Germany
| | - H-J Möller
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University and Genetics Research Centre GmbH, Munich, Germany
| | - A Hartmann
- Division of Molecular and Clinical Neurobiology, Department of Psychiatry, Ludwig-Maximilians-University and Genetics Research Centre GmbH, Munich, Germany
| | - C Crombie
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland
| | - G Fraser
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland
| | - N Walker
- Ravenscraig Hospital, Greenock, Scotland
| | - J Lonnqvist
- Department of Mental Health and Addiction, National Public Health Institute, Helsinki, Finland
| | - J Suvisaari
- Department of Mental Health and Addiction, National Public Health Institute, Helsinki, Finland
| | - A Tuulio-Henriksson
- Department of Mental Health and Addiction, National Public Health Institute, Helsinki, Finland
| | - E Bramon
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College, London, UK
| | - LA Kiemeney
- Department of Epidemiology & Biostatistics (133 EPIB)/Department of Urology (659 URO), Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - B Franke
- Department of Human Genetics, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - R Murray
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College, London, UK
| | - E Vassos
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College, London, UK
| | - T Toulopoulou
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College, London, UK
| | - TW Mühleisen
- Department of Genomics, Life & Brain Center, University of Bonn, Bonn, Germany
| | - S Tosato
- Section of Psychiatry and Clinical Psychology, University of Verona, Verona, Italy
| | - M Ruggeri
- Section of Psychiatry and Clinical Psychology, University of Verona, Verona, Italy
| | - S Djurovic
- Institute of Psychiatry, University of Oslo, Oslo, Norway
- Departments of Medical Genetics and Psychiatry, Ulleval University Hospital, Oslo, Norway
| | - OA Andreassen
- Institute of Psychiatry, University of Oslo, Oslo, Norway
- Departments of Medical Genetics and Psychiatry, Ulleval University Hospital, Oslo, Norway
| | - Z Zhang
- Department of Statistics, UCLA, Los Angeles, CA, USA
| | - T Werge
- Research Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Copenhagen University Hospital, Roskilde, Denmark
| | - RA Ophoff
- Department of Medical Genetics and Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands
- UCLA Center for Neurobehavioral Genetics and Department of Human Genetics, Los Angeles, CA, USA
| | | | - M Rietschel
- Department of Genetic Epidemiology in Psychiatry, Central Institute of Mental Health Mannheim, University of Heidelberg, Mannheim, Germany
| | - MM Nöthen
- Department of Genomics, Life & Brain Center, University of Bonn, Bonn, Germany
- Institute of Human Genetics, University of Bonn, Bonn, Germany
| | - H Petursson
- Department of Psychiatry, National University Hospital, Reykjavík, Iceland
| | | | - L Peltonen
- Department for Molecular Medicine, National Public Health Institute, Helsinki, Finland
- Wellcome Trust Sanger Institute, Hinxton, Cambridge, UK
- The Broad Institute, Cambridge, MA, USA
| | - D Collier
- Social, Genetic and Developmental Psychiatry Centre, Institute of Psychiatry, King’s College, London, UK
| | | | - DM St Clair
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, Scotland
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Hila L, Tébourbi H, Abeid L, Rejeb I, Chaabouni H. Subtelomeric microduplications in three sisters with moderate mental retardation. Biochem Genet 2010; 48:909-14. [PMID: 20811773 DOI: 10.1007/s10528-010-9371-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Accepted: 04/26/2010] [Indexed: 11/26/2022]
Abstract
Copy number changes of subtelomeric regions are a common cause of mental retardation, occurring in approximately 5% of mentally retarded patients. New molecular techniques allow the identification of subtelomeric microduplications. We report a Tunisian family of three sisters with moderate mental retardation, facial dysmorphism, cardiopathy, and bilateral clinodactyly of the third and fourth toes, explored by MLPA, showing the same associated microduplications, 15q and Xq, without a concurrent deletion.
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Affiliation(s)
- Lamia Hila
- Faculté de Médecine de Tunis, Laboratoire de Génétique Humaine, Tunisia.
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9
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MLPA subtelomere analysis in Tunisian mentally retarded patients. Biochem Genet 2009; 47:727-33. [PMID: 19590834 DOI: 10.1007/s10528-009-9271-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 06/24/2009] [Indexed: 12/08/2022]
Abstract
Subtelomeric rearrangements significantly contribute to idiopathic mental retardation and result in several mental retardation syndromes; however, most subtelomeric defects lack a characteristic phenotype. Thirty patients with unexplained mental retardation, a normal R banded karyotype at the 550 band, and no clinically recognizable syndrome were screened by Multiplex ligation-dependent probe amplification (MLPA). Four anomalies were identified: deletion 17q, duplications (4q), and associated duplications 15q and Xq. This duplication was found in two sisters of the proband. Anomalies were unidentified by the conventional technique. The prevalence of subtelomeric imbalances in our cohort of moderate to severe mental retardation is around 13% and is consistent with the literature. The sensitivity of the MLPA technique was characterized on cytogenetically verified positive and negative controls. MLPA is a fast, reliable, and relatively inexpensive technique to detect subtelomeric rearrangement in comparison with the fluorescence in situ hybridization (FISH) technique.
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Belligni EF, Biamino E, Molinatto C, Messa J, Pierluigi M, Faravelli F, Zuffardi O, Ferrero GB, Silengo MC. Subtelomeric FISH analysis in 76 patients with syndromic developmental delay/intellectual disability. Ital J Pediatr 2009; 35:9. [PMID: 19490664 PMCID: PMC2687548 DOI: 10.1186/1824-7288-35-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2008] [Accepted: 04/27/2009] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Intellectual disability affects approximately 1 to 3% of the general population. The etiology is still poorly understood and it is estimated that one-half of the cases are due to genetic factors. Cryptic subtelomeric aberrations have been found in roughly 5 to 7% of all cases. METHODS We performed a subtelomeric FISH analysis on 76 unrelated children with normal standard karyotype ascertained by developmental delay or intellectual disability, associated with congenital malformations, and/or facial dysmorphisms. RESULTS Ten cryptic chromosomal anomalies have been identified in the whole cohort (13,16%), 8 in the group of patients characterized by developmental delay or intellectual disability associated with congenital malformations and facial dysmorphisms, 2 in patients with developmental delay or intellectual disability and facial dysmorphisms only. CONCLUSION We demonstrate that a careful clinical examination is a very useful tool for pre-selection of patients for genomic analysis, clearly enhancing the chromosomal anomaly detection rate. Clinical features of most of these patients are consistent with the corresponding emerging chromosome phenotypes, pointing out these new clinical syndromes associated with specific genomic imbalances.
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Affiliation(s)
- Elga F Belligni
- Dipartimento di Scienze Pediatriche, University of Torino, Torino, Italy
| | - Elisa Biamino
- Dipartimento di Scienze Pediatriche, University of Torino, Torino, Italy
| | - Cristina Molinatto
- Dipartimento di Scienze Pediatriche, University of Torino, Torino, Italy
| | - Jole Messa
- Dipartimento di Biologia Generale e Genetica Medica, University of Pavia, Pavia, Italy
| | | | | | - Orsetta Zuffardi
- Dipartimento di Biologia Generale e Genetica Medica, University of Pavia, Pavia, Italy
| | - Giovanni B Ferrero
- Dipartimento di Scienze Pediatriche, University of Torino, Torino, Italy
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Ruiter EM, Koolen DA, Kleefstra T, Nillesen WM, Pfundt R, de Leeuw N, Hamel BCJ, Brunner HG, Sistermans EA, de Vries BBA. Pure subtelomeric microduplications as a cause of mental retardation. Clin Genet 2007; 72:362-8. [PMID: 17850634 DOI: 10.1111/j.1399-0004.2007.00874.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
Submicroscopic subtelomeric aberrations are a common cause of mental retardation (MR). New molecular techniques allow the identification of subtelomeric microduplications, but their frequency and significance are largely unknown. We determined the frequency of subtelomeric, pure microduplications in a cohort of 624 patients with MR and/or multiple congenital anomalies using multiplex ligation dependent probe amplification (MLPA) and delineated the identified microduplications using array based comparative genomic hybridization (array CGH). In 11 patients, MLPA revealed a subtelomeric duplication without a concurrent deletion. Additional fluorescence in situ hybridization studies and parental analyses showed that three had occurred de novo: one duplication 5q34qter (12.7 Mb), one duplication 9q34.13qter (7.2 Mb) and one duplication 9p24.2pter (4.1 Mb). Five microduplications (9p, 11q, 12q, 15q and 16p) appeared to be inherited from an unaffected parent, while in three cases (9p, 12p and 17p) the parents were not available for testing. Based on our findings and data from the literature, the three de novo duplications were the only ones likely to be disease-causing, leading to a frequency of pathogenic subtelomeric, pure microduplications of 0.5%. Our study shows that subtelomeric microduplications are an infrequent cause of MR and that additional clinical and family studies are required to assess their clinical significance.
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Affiliation(s)
- E M Ruiter
- Department of Human Genetics, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands
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12
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Harteveld CL, Kriek M, Bijlsma EK, Erjavec Z, Balak D, Phylipsen M, Voskamp A, di Capua E, White SJ, Giordano PC. Refinement of the genetic cause of ATR-16. Hum Genet 2007; 122:283-92. [PMID: 17598130 DOI: 10.1007/s00439-007-0399-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Accepted: 06/15/2007] [Indexed: 10/23/2022]
Abstract
Alpha thalassemia retardation associated with chromosome16 (ATR-16 syndrome) is defined as a contiguous gene syndrome resulting from haploinsufficiency of the alpha-globin gene cluster and genes involved in mental retardation (MR). To date, only few cases have been described which result from pure monosomy for a deletion of 16p. In most of these cases the deletion was identified by densitometric analysis of Southern blot results or by Fluorescent In Situ Hybridization analysis, and these alterations have not been mapped in detail. In this study, we have fine mapped deletions causing alpha-thalassemia within 2 Mb from the telomere of 16p by multiplex ligation-dependent probe amplification (MLPA). We have developed a rapid and simple test for high resolution mapping of rearrangements involving the tip of the short arm of chromosome 16 by incorporating 62 MLPA probes spaced approximately 10-200 kb over a region of 2 Mb from the telomere. One deletion of approximately 900 kb without MR was identified in addition to three de novo deletions varying between 1.5 and 2 Mb causing ATR-16 in three patients having mild MR and alpha-thalassemia. Two were found by chance to be ATR-16 because they were included in a study to search for telomeric loss in MR and not by hematological analysis. This would plead for more alertness when a persistent microcytic hypochromic anemia at normal ferritin levels is observed as suggestive for the ATR-16 syndrome. The region on chromosome 16p for which haploinsufficiency leads to the dysmorphic features and MR typical for ATR-16, has been narrowed down to a 800 kb region localized between 0.9 and 1.7 Mb from the telomere.
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Affiliation(s)
- Cornelis L Harteveld
- Department of Clinical Genetics, Center of Human and Clinical Genetics, Leiden University Medical Center (LUMC), 2333RC Leiden, The Netherlands.
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Murthy SK, Nygren AOH, El Shakankiry HM, Schouten JP, Al Khayat AI, Ridha A, Al Ali MT. Detection of a novel familial deletion of four genes between BP1 and BP2 of the Prader-Willi/Angelman syndrome critical region by oligo-array CGH in a child with neurological disorder and speech impairment. Cytogenet Genome Res 2007; 116:135-40. [PMID: 17268193 DOI: 10.1159/000097433] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2006] [Accepted: 06/05/2006] [Indexed: 01/06/2023] Open
Abstract
Two common classes of deletions are described in the literature in individuals with Prader-Willi/Angelman syndrome (PWS/AS): one between breakpoint 1 (BP1) to BP3 and the other between BP2 to BP3 of the PWS/AS critical region on chromosome 15q11-->q13. We present here a novel observation of an approximately 253-kb deletion between BP1 and BP2 on 15q11.2, in a 3(1/2)-year-old boy, who was referred to us with a clinical suspicion of having Angelman syndrome and presenting with mental retardation, neurological disorder, developmental delay and speech impairment. Karyotype and FISH results were found to be normal. The microdeletion between BP1 and BP2 includes four genes - NIPA1, NIPA2, CYFIP1 and TUBGCP5 which was detected by a high-resolution oligonucleotide array-CGH that was further validated by a Multiplex Ligation-dependent Probe Amplification (MLPA) assay. The same deletion was observed in the father who presented with similar but relatively milder clinical features as compared to the affected son. Methylation studies by methylation-specific MLPA (MS-MLPA) of the SNRPN imprinting center (IC) showed a normal imprinting pattern, both in the patient and the father. To our knowledge a microdeletion limited only to the BP1-BP2 region has not yet been reported. The familial genetic alteration together with the striking clinical presentation in this study are interesting, but from our single case study it is difficult to suggest if the deletion is causative of some of the abnormal features or if it is a normal variant. The study however further strengthens the fact that genome-wide analysis by array CGH in individuals with developmental delay and mental retardation is very useful in detecting such hidden interstitial chromosomal rearrangements.
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Affiliation(s)
- S K Murthy
- Genetics Department, Al Wasl Hospital, DOHMS, Dubai, UAE.
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Knight SJL, Regan R. Idiopathic learning disability and genome imbalance. Cytogenet Genome Res 2006; 115:215-24. [PMID: 17124403 DOI: 10.1159/000095917] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 04/28/2006] [Indexed: 12/08/2022] Open
Abstract
Learning disability (LD) is a very common, lifelong and disabling condition, affecting about 3% of the population. Despite this, it is only over the past 10-15 years that major progress has been made towards understanding the origins of LD. In particular, genetics driven advances in technology have led to the unequivocal demonstration of the importance of genome imbalance in the aetiology of idiopathic LD (ILD). In this review we provide an overview of these advances, discussing technologies such as multi-telomere FISH and array CGH that have already emerged as well as new approaches that show diagnostic potential for the future. The advances to date have highlighted new considerations such as copy number polymorphisms (CNPs) that can complicate the interpretation of genome imbalance and its relevance to ILD. More importantly though, they have provided a remarkable approximately 15-20% improvement in diagnostic capability as well as facilitating genotype/phenotype correlations and providing new avenues for the identification and understanding of genes involved in neurocognitive function.
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Affiliation(s)
- S J L Knight
- Oxford Genetics Knowledge Park, Wellcome Trust Centre for Human Genetics, University of Oxford, UK.
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15
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Saugier-Veber P, Goldenberg A, Drouin-Garraud V, de La Rochebrochard C, Layet V, Drouot N, Le Meur N, Gilbert-Du-Ssardier B, Joly-Hélas G, Moirot H, Rossi A, Tosi M, Frébourg T. Simple detection of genomic microdeletions and microduplications using QMPSF in patients with idiopathic mental retardation. Eur J Hum Genet 2006; 14:1009-17. [PMID: 16773131 DOI: 10.1038/sj.ejhg.5201661] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022] Open
Abstract
In contrast to the numerous well-known microdeletion syndromes, only a few microduplications have been described, and this discrepancy may be due in part to methodological bias. In order to facilitate the detection of genomic microdeletions and microduplications, we developed a new assay based on QMPSF (Quantitative Multiplex PCR of Short fluorescent Fragments) able to explore simultaneously 12 candidate loci involved in mental retardation (MR) and known to be the target of genomic rearrangements. We first screened 153 patients with MR and facial dysmorphism associated with malformations, or growth anomalies, or familial history, with cytogenetically normal chromosomes, and the absence of FRAXA mutation and subtelomeric rearrangements. In this series, we found a 5q35 deletion removing the NSD1 gene in a patient with severe epilepsy, profound MR and, retrospectively, craniofacial features of Sotos syndrome. In a second series, we screened 140 patients with MR and behaviour disturbance who did not fulfil the de Vries criteria for subtelomeric rearrangements and who had a normal karyotype and no detectable FRAXA mutation. We detected a 22q11 deletion in a patient with moderate MR, obesity, and facial dysmorphism and a 4 Mb 17p11 duplication in a patient with moderate MR, behaviour disturbance, strabismus, and aspecific facial features. This new QMPSF assay can be gradually upgraded to include additional loci involved in newly recognised microduplication/microdeletion syndromes, and should facilitate wide screenings of patients with idiopathic MR and provide better estimates of the microduplication frequency in the MR population.
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16
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Kriek M, Szuhai K, Kant SG, White SJ, Dauwerse H, Fiegler H, Carter NP, Knijnenburg J, den Dunnen JT, Tanke HJ, Breuning MH, Rosenberg C. A complex rearrangement on chromosome 22 affecting both homologues; haplo-insufficiency of the Cat eye syndrome region may have no clinical relevance. Hum Genet 2006; 120:77-84. [PMID: 16708226 DOI: 10.1007/s00439-006-0185-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 04/05/2006] [Indexed: 02/05/2023]
Abstract
The presence of highly homologous sequences, known as low copy repeats, predisposes for unequal recombination within the 22q11 region. This can lead to genomic imbalances associated with several known genetic disorders. We report here a developmentally delayed patient carrying different rearrangements on both chromosome 22 homologues, including a previously unreported rearrangement within the 22q11 region. One homologue carries a deletion of the proximal part of chromosome band 22q11. To our knowledge, a 'pure' deletion of this region has not been described previously. Four copies of this 22q11 region, however, are associated with Cat eye syndrome (CES). While the phenotypic impact of this deletion is unclear, familial investigation revealed five normal relatives carrying this deletion, suggesting that haplo-insufficiency of the CES region has little clinical relevance. The other chromosome 22 homologue carries a duplication of the Velocardiofacial/DiGeorge syndrome (VCFS/DGS) region. In addition, a previously undescribed deletion of 22q12.1, located in a relatively gene-poor region, was identified. As the clinical features of patients suffering from a duplication of the VCFS/DGS region have proven to be extremely variable, it is impossible to postulate as to the contribution of the 22q12.1 deletion to the phenotype of the patient. Additional patients with a deletion within this region are needed to establish the consequences of this copy number alteration. This study highlights the value of using different genomic approaches to unravel chromosomal alterations in order to study their phenotypic impact.
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Affiliation(s)
- Marjolein Kriek
- Center for Human and Clinical Genetics, Leiden University Medical Center, Einthovenweg, 2300 RC, Leiden, The Netherlands.
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17
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Le Caignec C, Boceno M, Saugier-Veber P, Jacquemont S, Joubert M, David A, Frebourg T, Rival JM. Detection of genomic imbalances by array based comparative genomic hybridisation in fetuses with multiple malformations. J Med Genet 2006; 42:121-8. [PMID: 15689449 PMCID: PMC1735978 DOI: 10.1136/jmg.2004.025478] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Malformations are a major cause of morbidity and mortality in full term infants and genomic imbalances are a significant component of their aetiology. However, the causes of defects in many patients with multiple congenital malformations remain unexplained despite thorough clinical examination and laboratory investigations. METHODS We used a commercially available array based comparative genomic hybridisation method (array CGH), able to screen all subtelomeric regions, main microdeletion syndromes, and 201 other regions covering the genome, to detect submicroscopic chromosomal imbalances in 49 fetuses with three or more significant anomalies and normal karyotype. RESULTS Array CGH identified eight genomic rearrangements (16.3%), all confirmed by quantitative multiplex PCR of short fluorescent fragments. Subtelomeric and interstitial deletions, submicroscopic duplications, and a complex genomic imbalance were identified. In four de novo cases (15qtel deletion, 16q23.1-q23.3 deletion, 22q11.2 deletion, and mosaicism for a rearranged chromosome 18), the genomic imbalance identified clearly underlay the pathological phenotype. In one case, the relationship between the genotype and phenotype was unclear, since a subtelomeric 6q deletion was detected in a mother and her two fetuses bearing multiple malformations. In three cases, a subtelomeric 10q duplication, probably a genomic polymorphism, was identified. CONCLUSIONS The detection of 5/49 causative chromosomal imbalances (or 4/49 if the 6qtel deletion is not considered as causative) suggests wide genome screening when standard chromosome analysis is normal and confirms that array CGH will have a major impact on pre and postnatal diagnosis as well as providing information for more accurate genetic counselling.
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Affiliation(s)
- C Le Caignec
- Service de Génétique Médicale, Institut de Biologie, Centre Hospitalier Universitaire, 9, quai Moncousu, 44093 Nantes Cedex, France.
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18
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Combes P, Bonnet-Dupeyron MN, Gauthier-Barichard F, Schiffmann R, Bertini E, Rodriguez D, Armour JAL, Boespflug-Tanguy O, Vaurs-Barrière C. PLP1 and GPM6B intragenic copy number analysis by MAPH in 262 patients with hypomyelinating leukodystrophies: identification of one partial triplication and two partial deletions of PLP1. Neurogenetics 2006; 7:31-7. [PMID: 16416265 DOI: 10.1007/s10048-005-0021-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Accepted: 09/15/2005] [Indexed: 02/03/2023]
Abstract
The proteolipid protein 1 (PLP1) gene is known to be mutated in the X-linked disorders of myelin formation Pelizaeus-Merzbacher disease (PMD) and spastic paraplegia type 2. The most commonly found PLP1 mutations are gene duplications (60-70%) and point mutations (20%). About 20% of patients with a PMD phenotype do not present identified PLP1 mutation, thus suggesting genetic heterogeneity and/or undetected PLP1 abnormalities. Except the recently described MLPA screening the seven exonic regions, the currently used techniques to quantify PLP1 gene copy number do not investigate small intragenic PLP1 rearrangements. Using the multiplex amplifiable probe hybridization (MAPH) technique, we looked simultaneously for intragenic rearrangements along the PLP1 gene (exonic and regulatory regions) and for rearrangements in the GPM6B candidate gene (a member of the proteolipid protein family). We tested 262 hypomyelinating patients: 56 PLP1 duplicated patients, 1 PLP1 triplicated patient, and 205 patients presenting a leukodystrophy of undetermined origin with brain MRI suggesting a defect in myelin formation. Our results show that MAPH is an alternative reliable technique for diagnosis of PLP1 gene copy number. It allows us (1) to demonstrate that all PLP1 duplications previously found encompass the whole gene, (2) to establish that copy number changes in GPM6B and intragenic duplications of PLP1 are very unlikely to be involved in the etiology of UHL, and (3) to identify one partial triplication and two partial deletions of PLP1 in patients presenting with a PMD phenotype.
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Affiliation(s)
- Patricia Combes
- INSERM U 384, Faculté de Médecine, Place Henri Dunant, 63000 Clermont-Ferrand, France
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19
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Moog U, Arens YHJM, van Lent-Albrechts JCM, Huijts PEA, Smeets EEJ, Schrander-Stumpel CTRM, Engelen JJM. Subtelomeric chromosome aberrations: still a lot to learn. Clin Genet 2005; 68:397-407. [PMID: 16207207 DOI: 10.1111/j.1399-0004.2005.00506.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
Subtelomeric chromosome aberrations: still a lot to learn.Cryptic subtelomeric chromosome aberrations are a significant cause of mental retardation (MR). More than 4000 patients have been investigated, and the mean overall prevalence of subtelomeric rearrangements has been found to be 5.2%. In order to contribute to knowledge on the clinical presentation of subtelomeric rearrangements, we retrospectively studied patients with unexplained MR who had been evaluated for subtelomeric abnormalities by different fluorescence in situ hybridization (FISH) techniques. Hundred and two patients had an unexplained combination of MR with dysmorphism, congenital anomalies, and/or a positive family history and were investigated by total subtelomeric (TS) FISH (89/102), or by total painting (TP) in an obligate carrier in the case of familial MR (13/102). In 59 additional patients, a sequence-specific FISH was performed on clinical indication. In the 102 patients studied by TS or TP, six pathogenic aberrations (5.9%) were found in addition to one polymorphism. In total, eight clinically significant subtelomeric aberrations were found in the 161 index patients; four of these eight aberrations were familial. We report on the clinical presentation of all patients with an aberration and review the relevant literature. Factors complicating the interpretation of subtelomeric rearrangements are discussed, such as the occurrence of variants, clinical variability, and limited knowledge of the phenotype.
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Affiliation(s)
- U Moog
- Department of Clinical Genetics, University Hospital Maastricht, the Netherlands.
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20
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Kok K, Dijkhuizen T, Swart YE, Zorgdrager H, van der Vlies P, Fehrmann R, te Meerman GJ, Gerssen-Schoorl KBJ, van Essen T, Sikkema-Raddatz B, Buys CHCM. Application of a comprehensive subtelomere array in clinical diagnosis of mental retardation. Eur J Med Genet 2005; 48:250-62. [PMID: 16179221 DOI: 10.1016/j.ejmg.2005.04.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2005] [Accepted: 04/08/2005] [Indexed: 12/08/2022]
Abstract
In 2-8% of patients with mental retardation, small copy number changes in the subtelomeric region are thought to be the underlying cause. As detection of these genomic rearrangements is labour intensive using FISH, we constructed and validated a high-density BAC/PAC array covering the first 5 Mb of all subtelomeric regions and applied it in our routine screening of patients with idiopathic mental retardation for submicroscopic telomeric rearrangements. The present study shows the efficiency of this comprehensive subtelomere array in detecting terminal deletions and duplications but also small interstitial subtelomeric rearrangements, starting from small amounts of DNA. With our array, the size of the affected segments, at least those smaller than 5 Mb, can be determined simultaneously in the same experiment. In the first 100 patient samples analysed in our diagnostic practice by the use of this comprehensive telomere array, we found three patients with deletions in 3p, 10q and 15q, respectively, four patients with duplications in 9p, 12p, 21q and Xp, respectively, and one patient with a del 6q/dup 16q. The patients with del 3p and 10q and dup 12p had interstitial rearrangements that would have been missed with techniques using one probe per subtelomeric region chosen close to the telomere.
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Affiliation(s)
- Klaas Kok
- Department of Clinical Genetics, University Medical Centre Groningen, Antonius Deusinglaan 4, 9713 AW Groningen, The Netherlands.
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21
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Bauters M, Van Esch H, Marynen P, Froyen G. X chromosome array-CGH for the identification of novel X-linked mental retardation genes. Eur J Med Genet 2005; 48:263-75. [PMID: 16179222 DOI: 10.1016/j.ejmg.2005.04.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Revised: 03/30/2005] [Accepted: 04/26/2005] [Indexed: 01/25/2023]
Abstract
Array-CGH technology for the detection of submicroscopic copy number changes in the genome has recently been developed for the identification of novel disease-associated genes. It has been estimated that submicroscopic genomic deletions or duplications will be present in 5-7% of patients with idiopathic mental retardation (MR). Since 30% more males than females are diagnosed with MR, we have developed a full coverage X chromosome array-CGH with a theoretical resolution of 82 kb, for the detection of copy number alterations in patients with suspected X-linked mental retardation (XLMR). First, we have validated the genomic location of X-derived clones through male versus female hybridisations. Next, we validated our array for efficient and reproducible detection of known alterations in XLMR patients. In all cases, we were able to detect the deletions and duplications in males as well as females. Due to the high resolution of our X-array, the boundaries of the genomic aberrations could clearly be identified making genotype-phenotype studies more reliable. Here, we describe the production and validation of a full coverage X-array-CGH, which will allow for fast and easy screening of submicroscopic copy number alterations in XLMR patients with the aim to identify novel MR genes or mechanisms involved in a deranged cognitive development.
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Affiliation(s)
- Marijke Bauters
- Human Genome Laboratory, Department of Human Genetics, Flanders Interuniversity Institute for Biotechnology (VIB), Leuven, Belgium
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22
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Patsalis PC, Kousoulidou L, Sismani C, Männik K, Kurg A. MAPH: from gels to microarrays. Eur J Med Genet 2005; 48:241-9. [PMID: 16179220 DOI: 10.1016/j.ejmg.2005.04.011] [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] [Received: 03/18/2005] [Revised: 03/18/2005] [Accepted: 04/07/2005] [Indexed: 12/15/2022]
Abstract
The development of accurate and sensitive methodologies to detect small chromosomal imbalances (<3 Mb) is extremely important in clinical diagnostics and research in human genetics. The technique of array-comparative genomic hybridization (CGH) using BAC and PAC clones is very sensitive methodology and is rapidly becoming the method of choice for high-resolution screening of genomic copy-number changes. An alternative methodology to CGH is the multiplex amplifiable probe hybridization (MAPH) methodology, a DNA based method that allows the accurate and reliable determination of changes in copy number in "known" or "unknown locations" in the human genome. MAPH uses probes of 100-500 bp in size, that can be specifically designed for any gene or locus in the genome and cover any gene exons, the subtelomeric or subcentromeric regions, any chromosomal segment, a whole chromosome or the total human genome. MAPH can provide extremely high resolution and enable the sensitive detection of loss or gain of genomic DNA sequences as small as 150 bp. Very recently we succeeded in the advancement of MAPH from gel and capillary analyses to microarrays. The array-MAPH methodology offers an alternative methodology to array-CGH and provides a new sensitive microarray-based method including several advantages for the detection of copy number changes in the human genome.
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Affiliation(s)
- Philippos C Patsalis
- Department of Cytogenetics, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus.
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23
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Rosenberg C, Knijnenburg J, Bakker E, Vianna-Morgante AM, Sloos W, Otto PA, Kriek M, Hansson K, Krepischi-Santos ACV, Fiegler H, Carter NP, Bijlsma EK, van Haeringen A, Szuhai K, Tanke HJ. Array-CGH detection of micro rearrangements in mentally retarded individuals: clinical significance of imbalances present both in affected children and normal parents. J Med Genet 2005; 43:180-6. [PMID: 15980116 PMCID: PMC2564641 DOI: 10.1136/jmg.2005.032268] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND The underlying causes of mental retardation remain unknown in about half the cases. Recent array-CGH studies demonstrated cryptic imbalances in about 25% of patients previously thought to be chromosomally normal. OBJECTIVE AND METHODS Array-CGH with approximately 3500 large insert clones spaced at approximately 1 Mb intervals was used to investigate DNA copy number changes in 81 mentally impaired individuals. RESULTS Imbalances never observed in control chromosomes were detected in 20 patients (25%): seven were de novo, nine were inherited, and four could not have their origin determined. Six other alterations detected by array were disregarded because they were shown by FISH either to hybridise to both homologues similarly in a presumptive deletion (one case) or to involve clones that hybridised to multiple sites (five cases). All de novo imbalances were assumed to be causally related to the abnormal phenotypes. Among the others, a causal relation between the rearrangements and an aberrant phenotype could be inferred in six cases, including two imbalances of the X chromosome, where the associated clinical features segregated as X linked recessive traits. CONCLUSIONS In all, 13 of 81 patients (16%) were found to have chromosomal imbalances probably related to their clinical features. The clinical significance of the seven remaining imbalances remains unclear. The limited ability to differentiate between inherited copy number variations which cause abnormal phenotypes and rare variants unrelated to clinical alterations currently constitutes a limitation in the use of CGH-microarray for guiding genetic counselling.
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24
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Coe BP, Henderson LJ, Garnis C, Tsao MS, Gazdar AF, Minna J, Lam S, Macaulay C, Lam WL. High-resolution chromosome arm 5p array CGH analysis of small cell lung carcinoma cell lines. Genes Chromosomes Cancer 2005; 42:308-13. [PMID: 15611929 DOI: 10.1002/gcc.20137] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Genomic amplification of regions on chromosome arm 5p has been observed frequently in small cell lung cancer (SCLC), implying the presence of multiple oncogenes on this arm. Although conventional comparative genomic hybridization (CGH) detects gross chromosomal copy number changes, gene discovery requires a higher-resolution approach in order to identify regions of alteration precisely. To identify candidate genes on this chromosome arm, we developed a high-resolution, 10-clone-per-megabase bacterial artificial chromosome CGH array for 5p and examined a panel of 15 SCLC cell lines. Utilization of this CGH array has allowed the fine-mapping of breakpoints to regions as small as 200 kb in a single experiment. In addition to reporting our observations of aberrations at the well-characterized SKP2 and TERT loci, we describe the identification of microdeletions that have escaped detection by conventional screens and the identification TRIO and ANKH as novel putative oncogenes.
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MESH Headings
- Biomarkers, Tumor/genetics
- Biomarkers, Tumor/metabolism
- Carcinoma, Small Cell/genetics
- Chromosome Aberrations
- Chromosome Mapping
- Chromosomes, Artificial, Bacterial
- Chromosomes, Human, Pair 5/ultrastructure
- DNA/genetics
- Female
- Gene Expression Profiling
- Gene Expression Regulation, Neoplastic
- Humans
- In Situ Hybridization, Fluorescence
- Karyotyping
- Lung Neoplasms/genetics
- Male
- Nucleic Acid Hybridization
- Oligonucleotide Array Sequence Analysis
- Tumor Cells, Cultured
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Affiliation(s)
- Bradley P Coe
- British Columbia Cancer Research Centre, Vancouver, British Columbia, Canada.
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25
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Rooms L, Reyniers E, Kooy RF. Subtelomeric rearrangements in the mentally retarded: A comparison of detection methods. Hum Mutat 2005; 25:513-24. [PMID: 15880643 DOI: 10.1002/humu.20185] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/08/2022]
Abstract
In recent years, subtelomeric rearrangements, e.g., chromosome deletions or duplications too small to be detected by conventional cytogenetic analysis, have emerged as a significant cause of both idiopathic and familial mental retardation. As mental retardation is a common disorder, many patients need to be tested on a routine basis. In this review, we will discuss the different methods that have been applied in laboratories worldwide, including multiprobe fluorescence in situ hybridization (FISH), multiallelic marker analysis, multiplex amplifiable probe hybridization (MAPH), multiplex ligation-dependent probe amplification (MLPA), quantitative real-time PCR, comparative genomic hybridization (CGH), and multicolor FISH, including spectral karyotyping (SKY), subtelomeric combined binary ratio labeling FISH (S-COBRA FISH), multiplex FISH telomere integrity assay (M-TEL), telomeric multiplex FISH (TM-FISH), and primed in situ labeling (PRINS).
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Affiliation(s)
- Liesbeth Rooms
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
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26
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Pickard BS, Hollox EJ, Malloy MP, Porteous DJ, Blackwood DHR, Armour JAL, Muir WJ. A 4q35.2 subtelomeric deletion identified in a screen of patients with co-morbid psychiatric illness and mental retardation. BMC MEDICAL GENETICS 2004; 5:21. [PMID: 15310400 PMCID: PMC515177 DOI: 10.1186/1471-2350-5-21] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2004] [Accepted: 08/13/2004] [Indexed: 12/08/2022]
Abstract
Background Cryptic structural abnormalities within the subtelomeric regions of chromosomes have been the focus of much recent research because of their discovery in a percentage of people with mental retardation (UK terminology: learning disability). These studies focused on subjects (largely children) with various severities of intellectual impairment with or without additional physical clinical features such as dysmorphisms. However it is well established that prevalence of schizophrenia is around three times greater in those with mild mental retardation. The rates of bipolar disorder and major depressive disorder have also been reported as increased in people with mental retardation. We describe here a screen for telomeric abnormalities in a cohort of 69 patients in which mental retardation co-exists with severe psychiatric illness. Methods We have applied two techniques, subtelomeric fluorescence in situ hybridisation (FISH) and multiplex amplifiable probe hybridisation (MAPH) to detect abnormalities in the patient group. Results A subtelomeric deletion was discovered involving loss of 4q in a patient with co-morbid schizoaffective disorder and mental retardation. Conclusion The precise region of loss has been defined allowing us to identify genes that may contribute to the clinical phenotype through hemizygosity. Interestingly, the region of 4q loss exactly matches that linked to bipolar affective disorder in a large multiply affected Australian kindred.
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Affiliation(s)
- Ben S Pickard
- Medical Genetics, Molecular Medicine Centre, Univ. of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Edward J Hollox
- Institute of Genetics, Univ. of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - M Pat Malloy
- Medical Genetics, Molecular Medicine Centre, Univ. of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
- Psychiatry, Univ. of Edinburgh, Royal Edinburgh Hospital, Morningside Park, Edinburgh, EH10 5HF, UK
| | - David J Porteous
- Medical Genetics, Molecular Medicine Centre, Univ. of Edinburgh, Western General Hospital, Crewe Road, Edinburgh, EH4 2XU, UK
| | - Douglas HR Blackwood
- Psychiatry, Univ. of Edinburgh, Royal Edinburgh Hospital, Morningside Park, Edinburgh, EH10 5HF, UK
| | - John AL Armour
- Institute of Genetics, Univ. of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Walter J Muir
- Psychiatry, Univ. of Edinburgh, Royal Edinburgh Hospital, Morningside Park, Edinburgh, EH10 5HF, UK
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