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Zhuang J, Zhang N, Wang J, Jiang Y, Zhang H, Chen C. Initial clinical and molecular investigation of 20q13.33 microdeletion with 17q25.3/14q32.31q32.33 microduplication in Chinese pediatric patients. Mol Genet Genomic Med 2024; 12:e2429. [PMID: 38553934 PMCID: PMC10980884 DOI: 10.1002/mgg3.2429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 03/01/2024] [Accepted: 03/19/2024] [Indexed: 04/02/2024] Open
Abstract
BACKGROUND Limited research has been conducted regarding the elucidation of genotype-phenotype correlations within the 20q13.33 region. The genotype-phenotype association of 20q13.33 microdeletion remains inadequately understood. In the present study, two novel cases of 20q13.33 microdeletion were introduced, with the objective of enhancing understanding of the genotype-phenotype relationship. METHODS Two unrelated patients with various abnormal clinical phenotypes from Fujian province Southeast China were enrolled in the present study. Karyotype analysis and chromosomal microarray analysis (CMA) were performed to investigate chromosomal abnormalities and copy number variants. RESULTS The results of high-resolution G-banding karyotype analysis elicited a 46,XY,der(20)add(20)(q13.3) in Patient 1. This patient exhibited various clinical manifestations, such as global developmental delay, intellectual disability, seizures, and other congenital diseases. Subsequently, a 1.0-Mb deletion was identified in the 20q13.33 region alongside a 5.2-Mb duplication in the 14q32.31q32.33 region. In Patient 2, CMA results revealed a 1.8-Mb deletion in the 20q13.33 region with a 4.8-Mb duplication of 17q25.3. The patient exhibited additional abnormal clinical features, including micropenis, congenital heart disease, and a distinctive crying pattern characterized by a crooked mouth. CONCLUSION In the present study, for the first time, an investigation was conducted into two novel cases of 20q13.33 microdeletion with microduplications in the 17q25.3 and 14q32.31q32.33 regions in the Chinese population. The presence of micropenis may be attributed to the 20q13.33 microdeletion, potentially expanding the phenotypic spectrum associated with this deletion.
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Affiliation(s)
- Jianlong Zhuang
- Prenatal Diagnosis Center, Quanzhou Women's and Children's HospitalQuanzhouChina
| | - Na Zhang
- Prenatal Diagnosis Center, Quanzhou Women's and Children's HospitalQuanzhouChina
| | - Junyu Wang
- Prenatal Diagnosis Center, Quanzhou Women's and Children's HospitalQuanzhouChina
| | - Yuying Jiang
- Prenatal Diagnosis Center, Quanzhou Women's and Children's HospitalQuanzhouChina
| | - Hegan Zhang
- Department of GynecologyQuanzhou Women's and Children's HospitalQuanzhouChina
| | - Chunnuan Chen
- Department of NeurologyThe Second Affiliated Hospital of Fujian Medical UniversityQuanzhouChina
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Xiao T, Chen X, Xu Y, Chen H, Dong X, Yang L, Wu B, Chen L, Li L, Zhuang D, Chen D, Zhou Y, Wang H, Zhou W. Clinical Study of 30 Novel KCNQ2 Variants/Deletions in KCNQ2-Related Disorders. Front Mol Neurosci 2022; 15:809810. [PMID: 35557555 PMCID: PMC9088225 DOI: 10.3389/fnmol.2022.809810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 03/02/2022] [Indexed: 11/24/2022] Open
Abstract
Background KCNQ2-related disorder is typically characterized as neonatal onset seizure and epileptic encephalopathy. The relationship between its phenotype and genotype is still elusive. This study aims to provide clinical features, management, and prognosis of patients with novel candidate variants of the KCNQ2 gene. Methods We enrolled patients with novel variants in the KCNQ2 gene from the China Neonatal Genomes Project between January 2018 and January 2021. All patients underwent next-generation sequencing tests and genetic data were analyzed by an in-house pipeline. The pathogenicity of variants was classified according to the guideline of the American College of Medical Genetics. Each case was evaluated by two geneticists back to back. Patients' information was acquired from clinical records. Results A total of 30 unrelated patients with novel variants in the KCNQ2 gene were identified, including 19 patients with single-nucleotide variants (SNVs) and 11 patients with copy number variants (CNVs). For the 19 SNVs, 12 missense variants and 7 truncating variants were identified. Of them, 36.8% (7/19) of the KCNQ2 variants were located in C-terminal regions, 15.7% (3/19) in segment S2, and 15.7% (3/19) in segment S4. Among them, 18 of 19 patients experienced seizures in the early neonatal period. However, one patient presented neurodevelopmental delay (NDD) as initial phenotype when he was 2 months old, and he had severe NDD when he was 3 years old. This patient did not present seizure but had abnormal electrographic background activity and brain imaging. Moreover, for the 11 patients with CNVs, 20q13.3 deletions involving EEF1A2, KCNQ2, and CHRNA4 genes were detected. All of them presented neonatal-onset seizures, responded to antiepileptic drugs, and had normal neurological development. Conclusion In this study, patients with novel KCNQ2 variants have variable phenotypes, whereas patients with 20q13.3 deletion involving EEF1A2, KCNQ2, and CHRNA4 genes tend to have normal neurological development.
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Affiliation(s)
- Tiantian Xiao
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Xiang Chen
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Yan Xu
- Division of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Huiyao Chen
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Xinran Dong
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Lin Yang
- Department of Endocrinology and Inherited Metabolic Diseases, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Bingbing Wu
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
| | - Liping Chen
- Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Long Li
- Department of Neonatology, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | | | - Dongmei Chen
- Quanzhou Women and Children's Hospital, Quanzhou, China
| | - Yuanfeng Zhou
- Division of Neurology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- *Correspondence: Yuanfeng Zhou
| | - Huijun Wang
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- Huijun Wang
| | - Wenhao Zhou
- Department of Neonatology, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
- Center for Molecular Medicine, National Children's Medical Center, Children's Hospital of Fudan University, Shanghai, China
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Candidate Genes Associated with Delayed Neuropsychomotor Development and Seizures in a Patient with Ring Chromosome 20. Case Rep Genet 2020; 2020:5957415. [PMID: 32082653 PMCID: PMC6995492 DOI: 10.1155/2020/5957415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 12/17/2019] [Indexed: 11/25/2022] Open
Abstract
Ring chromosome 20 (r20) is characterized by intellectual impairment, behavioral disorders, and refractory epilepsy. We report a patient presenting nonmosaic ring chromosome 20 followed by duplication and deletion in 20q13.33 with seizures, delayed neuropsychomotor development and language, mild hypotonia, low weight gain, and cognitive deficit. Chromosomal microarray analysis (CMA) enabled us to restrict a chromosomal segment and thus integrate clinical and molecular data with systems biology. With this approach, we were able to identify candidate genes that may help to explain the consequences of deletions in 20q13.33. In our analysis, we observed five hubs (ARFGAP1, HELZ2, COL9A3, PTK6, and EEF1A2), seven bottlenecks (CHRNA4, ARFRP1, GID8, COL9A3, PTK6, ZBTB46, and SRMS), and two H-B nodes (PTK6 and COL9A3). The candidate genes may play an important role in the developmental delay and seizures observed in r20 patients. Gene ontology included microtubule-based movement, nucleosome assembly, DNA repair, and cholinergic synaptic transmission. Defects in these bioprocesses are associated with the development of neurological diseases, intellectual disability, neuropathies, and seizures. Therefore, in this study, we can explore molecular cytogenetic data, identify proteins through network analysis of protein-protein interactions, and identify new candidate genes associated with the main clinical findings in patients with 20q13.33 deletions.
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Oikonomakis V, Kosma K, Mitrakos A, Sofocleous C, Pervanidou P, Syrmou A, Pampanos A, Psoni S, Fryssira H, Kanavakis E, Kitsiou-Tzeli S, Tzetis M. Recurrent copy number variations as risk factors for autism spectrum disorders: analysis of the clinical implications. Clin Genet 2016; 89:708-18. [PMID: 26777411 DOI: 10.1111/cge.12740] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/08/2016] [Accepted: 01/13/2016] [Indexed: 12/31/2022]
Abstract
Chromosomal microarray analysis (CMA) is currently considered a first-tier diagnostic assay for the investigation of autism spectrum disorders (ASD), developmental delay and intellectual disability of unknown etiology. High-resolution arrays were utilized for the identification of copy number variations (CNVs) in 195 ASD patients of Greek origin (126 males, 69 females). CMA resulted in the detection of 65 CNVs, excluding the known polymorphic copy number polymorphisms also found in the Database of Genomic Variants, for 51/195 patients (26.1%). Parental DNA testing in 20/51 patients revealed that 17 CNVs were de novo, 6 paternal and 3 of maternal origin. The majority of the 65 CNVs were deletions (66.1%), of which 5 on the X-chromosome while the duplications, of which 7 on the X-chromosome, were rarer (22/65, 33.8%). Fifty-one CNVs from a total of 65, reported for our cohort of ASD patients, were of diagnostic significance and well described in the literature while 14 CNVs (8 losses, 6 gains) were characterized as variants of unknown significance and need further investigation. Among the 51 patients, 39 carried one CNV, 10 carried two CNVs and 2 carried three CNVs. The use of CMA, its clinical validity and utility was assessed.
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Affiliation(s)
- V Oikonomakis
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - K Kosma
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - A Mitrakos
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - C Sofocleous
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.,Research Institute for the Study of Genetic and Malignant Diseases in Childhood, "Aghia Sophia" Children's Hospital, Athens, Greece
| | - P Pervanidou
- 1st Department of Pediatrics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - A Syrmou
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - A Pampanos
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.,Department of Genetics, "Alexandra" University Maternal Hospital, Athens, Greece
| | - S Psoni
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - H Fryssira
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - E Kanavakis
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece.,Research Institute for the Study of Genetic and Malignant Diseases in Childhood, "Aghia Sophia" Children's Hospital, Athens, Greece
| | - S Kitsiou-Tzeli
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - M Tzetis
- Department of Medical Genetics, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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A novel de novo 20q13.32-q13.33 deletion in a 2-year-old child with poor growth, feeding difficulties and low bone mass. J Hum Genet 2015; 60:313-7. [PMID: 25761574 DOI: 10.1038/jhg.2015.22] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 01/30/2015] [Accepted: 02/04/2015] [Indexed: 11/08/2022]
Abstract
Interstitial deletions of the long arm of chromosome 20 are rarely reported in the literature. We report a 2-year-old child with a 2.6 Mb deletion of 20q13.32-q13.33, detected by microarray-based comparative genomic hybridization, who presented with poor growth, feeding difficulties, abnormal subcutaneous fat distribution with the lack of adipose tissue on clinical examination, facial dysmorphism and low bone mass. This report adds to rare publications describing constitutional aberrations of chromosome 20q, and adds further evidence to the fact that deletion of the GNAS complex may not always be associated with an Albright's hereditary osteodystrophy phenotype as described previously.
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Allen NM, Mannion M, Conroy J, Lynch SA, Shahwan A, Lynch B, King MD. The variable phenotypes of KCNQ-related epilepsy. Epilepsia 2014; 55:e99-105. [DOI: 10.1111/epi.12715] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2014] [Indexed: 11/28/2022]
Affiliation(s)
- Nicholas M. Allen
- Department of Paediatric Neurology & Clinical Neurophysiology; Children's University Hospital; Dublin Ireland
| | - Maria Mannion
- Department of Paediatric Neurology & Clinical Neurophysiology; Children's University Hospital; Dublin Ireland
| | - Judith Conroy
- Academic Centre on Rare Diseases; School of Medicine and Medical Science; University College; Dublin Ireland
| | - Sally A. Lynch
- Academic Centre on Rare Diseases; School of Medicine and Medical Science; University College; Dublin Ireland
- Department of Clinical Genetics; Children's University Hospital; Temple St. Dublin Ireland
| | - Amre Shahwan
- Department of Paediatric Neurology & Clinical Neurophysiology; Children's University Hospital; Dublin Ireland
| | - Bryan Lynch
- Department of Paediatric Neurology & Clinical Neurophysiology; Children's University Hospital; Dublin Ireland
| | - Mary D. King
- Department of Paediatric Neurology & Clinical Neurophysiology; Children's University Hospital; Dublin Ireland
- Academic Centre on Rare Diseases; School of Medicine and Medical Science; University College; Dublin Ireland
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Tzetis M, Kitsiou-Tzeli S, Frysira H, Xaidara A, Kanavakis E. The clinical utility of molecular karyotyping using high-resolution array-comparative genomic hybridization. Expert Rev Mol Diagn 2014; 12:449-57. [DOI: 10.1586/erm.12.40] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Maria Tzetis
- Department of Medical Genetics, Aghia Sophia Childrens Hospital, Thivon & Levadias, Medical School, University of Athens, 11527, Athens, Greece
- Department of Medical Genetics, Aghia Sophia Childrens Hospital, Thivon & Levadias, Medical School, University of Athens, 11527, Athens, Greece
| | - Sofia Kitsiou-Tzeli
- Department of Medical Genetics, Aghia Sophia Childrens Hospital, Thivon & Levadias, Medical School, University of Athens, 11527, Athens, Greece
| | - Helen Frysira
- Department of Medical Genetics, Aghia Sophia Childrens Hospital, Thivon & Levadias, Medical School, University of Athens, 11527, Athens, Greece
| | - Athena Xaidara
- First Department of Pediatrics, Aghia Sophia, Children’s Hospital, Medical School, University of Athens, Greece
| | - Emmanuel Kanavakis
- Department of Medical Genetics, Aghia Sophia Childrens Hospital, Thivon & Levadias, Medical School, University of Athens, 11527, Athens, Greece
- Research Institute for the Study of Genetic and Malignant Disorders in Childhood, Aghia Sophia, Children’s Hospital, Athens, Greece
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Pascual FT, Wierenga KJ, Ng YT. Contiguous deletion of KCNQ2 and CHRNA4 may cause a different disorder from benign familial neonatal seizures. EPILEPSY & BEHAVIOR CASE REPORTS 2013; 1:35-8. [PMID: 25667822 PMCID: PMC4150641 DOI: 10.1016/j.ebcr.2013.01.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 01/31/2013] [Indexed: 11/19/2022]
Abstract
Benign familial neonatal seizures (BFNS) is an autosomal dominant disorder associated with heterozygous mutations of either the KCNQ2 or KCNQ3 gene. Most cases have mutations of the KCNQ2 gene. A handful of cases with KCNQ2 and CHRNA4 deletions have been identified with different phenotypic presentations. Only two cases presented with typical BFNS features. Benign familial neonatal seizures is associated with normal exam and work-up, and seizure remission is seen in the first month of life. We report three unrelated individuals with KCNQ2 and CHRNA4 deletions, presenting with neonatal seizures and developmental delay. Their seizures started within one week after birth; all required antiepileptic drugs. Each had normal brain magnetic resonance imaging and at least two electroencephalograms with either normal or abnormal findings. All were developmentally delayed. None presented with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) phenotype associated with CHRNA4 mutation. This study supports reports of KCNQ2 and CHRNA4 deletions associated with phenotypes different from typical BFNS.
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Affiliation(s)
- Franchette T. Pascual
- Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Corresponding author at: Department of Neurology, OUHSC, 711 Stanton L. Young Boulevard, Suite 210, Oklahoma City, OK 73104, USA. Tel.: + 1 405 271 4113.
| | - Klaas J. Wierenga
- Department of Pediatrics, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Yu-Tze Ng
- Department of Neurology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
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Mefford HC, Cook J, Gospe SM. Epilepsy due to 20q13.33 subtelomere deletion masquerading as pyridoxine-dependent epilepsy. Am J Med Genet A 2012; 158A:3190-5. [DOI: 10.1002/ajmg.a.35633] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 07/30/2012] [Indexed: 02/03/2023]
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Traylor RN, Bruno DL, Burgess T, Wildin R, Spencer A, Ganesamoorthy D, Amor DJ, Hunter M, Caplan M, Rosenfeld JA, Theisen A, Torchia BS, Shaffer LG, Ballif BC, Slater HR. A genotype-first approach for the molecular and clinical characterization of uncommon de novo microdeletion of 20q13.33. PLoS One 2010; 5:e12462. [PMID: 20805988 PMCID: PMC2929201 DOI: 10.1371/journal.pone.0012462] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 06/16/2010] [Indexed: 11/21/2022] Open
Abstract
Background Subtelomeric deletions of the long arm of chromosome 20 are rare, with only 11 described in the literature. Clinical features of individuals with these microdeletions include severe limb malformations, skeletal abnormalities, growth retardation, developmental and speech delay, mental retardation, seizures and mild, non-specific dysmorphic features. Methodology/Principal Findings We characterized microdeletions at 20q13.33 in six individuals referred for genetic evaluation of developmental delay, mental retardation, and/or congenital anomalies. A comparison to previously reported cases of 20q13.33 microdeletion shows phenotypic overlap, with clinical features that include mental retardation, developmental delay, speech and language deficits, seizures, and behavior problems such as autistic spectrum disorder. There does not appear to be a clinically recognizable constellation of dysmorphic features among individuals with subtelomeric 20q microdeletions. Conclusions/Significance Based on genotype-phenotype correlation among individuals in this and previous studies, we discuss several possible candidate genes for specific clinical features, including ARFGAP1, CHRNA4 and KCNQ2 and neurodevelopmental deficits. Deletion of this region may play an important role in cognitive development.
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Affiliation(s)
- Ryan N Traylor
- Signature Genomic Laboratories, Spokane, Washington, United States of America
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Wang BT, Hemmat M, Jayakar P, Boyar F, Chan P, El Naggar M, Anguiano A. Paternal mosaic inv(20) resulting in a recombinant chromosome 20 in two siblings. Pediatr Int 2010; 52:492-5. [PMID: 20723126 DOI: 10.1111/j.1442-200x.2010.03041.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bao-Tyan Wang
- Cytogenetics Department, Quest Diagnostics Nichols Institute, San Juan Capistrano, California, USA
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Descipio C, Morrissette JD, Conlin LK, Clark D, Kaur M, Coplan J, Riethman H, Spinner NB, Krantz ID. Two siblings with alternate unbalanced recombinants derived from a large cryptic maternal pericentric inversion of chromosome 20. Am J Med Genet A 2010; 152A:373-82. [PMID: 20101690 DOI: 10.1002/ajmg.a.33219] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Two brothers, with dissimilar clinical features, were each found to have different abnormalities of chromosome 20 by subtelomere fluorescence in situ hybridization (FISH). The proband had deletion of 20p subtelomere and duplication of 20q subtelomere, while his brother was found to have a duplication of 20p subtelomere and deletion of 20q subtelomere. Parental cytogenetic studies were initially thought to be normal, both by G-banding and by subtelomere FISH analysis. Since chromosome 20 is a metacentric chromosome and an inversion was suspected, we used anchored FISH to assist in identifying a possible inversion. This approach employed concomitant hybridization of a FISH probe to the short (p) arm of chromosome 20 with the 20q subtelomere probe. We identified a cytogenetically non-visible, mosaic pericentric inversion of one of the maternal chromosome 20 homologs, providing a mechanistic explanation for the chromosomal abnormalities present in these brothers. Array comparative genomic hybridization (CGH) with both a custom-made BAC and cosmid-based subtelomere specific array (TEL array) and a commercially available SNP-based array confirmed and further characterized these rearrangements, identifying this as the largest pericentric inversion of chromosome 20 described to date. TEL array data indicate that the 20p breakpoint is defined by BAC RP11-978M13, approximately 900 kb from the pter; SNP array data reveal this breakpoint to occur within BAC RP11-978M13. The 20q breakpoint is defined by BAC RP11-93B14, approximately 1.7 Mb from the qter, by TEL array; SNP array data refine this breakpoint to within a gap between BACs on the TEL array (i.e., between RP11-93B14 and proximal BAC RP11-765G16).
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Affiliation(s)
- Cheryl Descipio
- Division of Human Genetics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104, USA
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