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Engwerda A, Kerstjens-Frederikse WS, Corsten-Janssen N, Dijkhuizen T, van Ravenswaaij-Arts CMA. The phenotypic spectrum of terminal 6q deletions based on a large cohort derived from social media and literature: a prominent role for DLL1. Orphanet J Rare Dis 2023; 18:59. [PMID: 36935482 PMCID: PMC10024851 DOI: 10.1186/s13023-023-02658-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 02/27/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Terminal 6q deletions are rare, and the number of well-defined published cases is limited. Since parents of children with these aberrations often search the internet and unite via international social media platforms, these dedicated platforms may hold valuable knowledge about additional cases. The Chromosome 6 Project is a collaboration between researchers and clinicians at the University Medical Center Groningen and members of a Chromosome 6 support group on Facebook. The aim of the project is to improve the surveillance of patients with chromosome 6 aberrations and the support for their families by increasing the available information about these rare aberrations. This parent-driven research project makes use of information collected directly from parents via a multilingual online questionnaire. Here, we report our findings on 93 individuals with terminal 6q deletions and 11 individuals with interstitial 6q26q27 deletions, a cohort that includes 38 newly identified individuals. RESULTS Using this cohort, we can identify a common terminal 6q deletion phenotype that includes microcephaly, dysplastic outer ears, hypertelorism, vision problems, abnormal eye movements, dental abnormalities, feeding problems, recurrent infections, respiratory problems, spinal cord abnormalities, abnormal vertebrae, scoliosis, joint hypermobility, brain abnormalities (ventriculomegaly/hydrocephaly, corpus callosum abnormality and cortical dysplasia), seizures, hypotonia, ataxia, torticollis, balance problems, developmental delay, sleeping problems and hyperactivity. Other frequently reported clinical characteristics are congenital heart defects, kidney problems, abnormalities of the female genitalia, spina bifida, anal abnormalities, positional foot deformities, hypertonia and self-harming behaviour. The phenotypes were comparable up to a deletion size of 7.1 Mb, and most features could be attributed to the terminally located gene DLL1. Larger deletions that include QKI (> 7.1 Mb) lead to a more severe phenotype that includes additional clinical characteristics. CONCLUSIONS Terminal 6q deletions cause a common but highly variable phenotype. Most clinical characteristics can be linked to the smallest terminal 6q deletions that include the gene DLL1 (> 500 kb). Based on our findings, we provide recommendations for clinical follow-up and surveillance of individuals with terminal 6q deletions.
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Affiliation(s)
- Aafke Engwerda
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | | | - Nicole Corsten-Janssen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Trijnie Dijkhuizen
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Conny M A van Ravenswaaij-Arts
- Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
- ATN/Jonx, Groningen, The Netherlands.
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Congenital Brain Malformations: An Integrated Diagnostic Approach. Semin Pediatr Neurol 2022; 42:100973. [PMID: 35868725 DOI: 10.1016/j.spen.2022.100973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 11/24/2022]
Abstract
Congenital brain malformations are abnormalities present at birth that can result from developmental disruptions at various embryonic or fetal stages. The clinical presentation is nonspecific and can include developmental delay, hypotonia, and/or epilepsy. An informed combination of imaging and genetic testing enables early and accurate diagnosis and management planning. In this article, we provide a streamlined approach to radiologic phenotyping and genetic evaluation of brain malformations. We will review the clinical workflow for brain imaging and genetic testing with up-to-date ontologies and literature references. The organization of this article introduces a streamlined approach for imaging-based etiologic classification into malformative, destructive, and migrational abnormalities. Specific radiologic ontologies are then discussed in detail, with correlation of key neuroimaging features to embryology and molecular pathogenesis.
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Vriend I, Oegema R. Genetic causes underlying grey matter heterotopia. Eur J Paediatr Neurol 2021; 35:82-92. [PMID: 34666232 DOI: 10.1016/j.ejpn.2021.09.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/21/2021] [Indexed: 11/15/2022]
Abstract
Grey matter heterotopia (GMH) can cause of seizures and are associated with a wide range of neurodevelopmental disorders and syndromes. They are caused by a failure of neuronal migration during fetal development, leading to clusters of neurons that have not reached their final destination in the cerebral cortex. We have performed an extensive literature search in Pubmed, OMIM, and Google scholar and provide an overview of known genetic associations with periventricular nodular heterotopia (PNVH), subcortical band heterotopia (SBH) and other subcortical heterotopia (SUBH). We classified the heterotopias as PVNH, SBH, SUBH or other and collected the genetic information, frequency, imaging features and salient features in tables for every subtype of heterotopia. This resulted in 105 PVNH, 16 SBH and 25 SUBH gene/locus associations, making a total of 146 genes and chromosomal loci. Our study emphasizes the extreme genetic heterogeneity underlying GMH. It will aid the clinician in establishing an differential diagnosis and eventually a molecular diagnosis in GMH patients. A diagnosis enables proper counseling of prognosis and recurrence risks, and enables individualized patient management.
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Affiliation(s)
- Ilona Vriend
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Renske Oegema
- Department of Genetics, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.
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Corona-Rivera JR, Corona-Rivera A, Zepeda-Romero LC, Rios-Flores IM, Rivera-Vargas J, Orozco-Vela M, Santana-Bejarano UF, Torres-Anguiano E, Pinto-Cardoso M, David D, Bobadilla-Morales L. Ring chromosome 6 in a child with anterior segment dysgenesis and review of its overlap with other FOXC1 deletion phenotypes. Congenit Anom (Kyoto) 2019; 59:174-178. [PMID: 30225942 DOI: 10.1111/cga.12309] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 09/11/2018] [Accepted: 09/12/2018] [Indexed: 12/25/2022]
Abstract
Here, we report a patient with ring chromosome 6 [r(6)], associated with anterior segment dysgenesis (ASD) and other anomalies. The phenotype was due to a 1880 kb microdeletion at 6p25.3 identified by whole-genome array analysis, and was mainly attributable to a FOXC1 haploinsufficiency. Currently 37 patients with r(6) have been reported. We found that facial dysmorphism, ASD, heart anomalies, brain anomalies, and hearing loss are constant features only in severe cases of r(6), mainly related to hemizygosity of FOXC1. Thus, overlaps with other FOXC1 related phenotypes, such as the 6p25 deletion syndrome, Axenfeld-Rieger syndrome type 3, and ASD type 3. Contrarily, those patients whose r(6) does not disrupt FOXC1, have mild or moderate phenotypes and do not exhibit ASD.
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Affiliation(s)
- Jorge Román Corona-Rivera
- Center for Registry and Research on Congenital Anomalies (CRIAC), Service of Genetics and Cytogenetics Unit, Division of Pediatrics, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Guadalajara, Mexico.,'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Alfredo Corona-Rivera
- Center for Registry and Research on Congenital Anomalies (CRIAC), Service of Genetics and Cytogenetics Unit, Division of Pediatrics, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Guadalajara, Mexico.,'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Luz Consuelo Zepeda-Romero
- Service of Ophthalmology, Division of Pediatrics, 'Fray Antonio Alcalde' Civil Hospital of Guadalajara, Guadalajara, Mexico
| | - Izabel Maryalexandra Rios-Flores
- Center for Registry and Research on Congenital Anomalies (CRIAC), Service of Genetics and Cytogenetics Unit, Division of Pediatrics, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Guadalajara, Mexico
| | - Jehú Rivera-Vargas
- Center for Registry and Research on Congenital Anomalies (CRIAC), Service of Genetics and Cytogenetics Unit, Division of Pediatrics, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Guadalajara, Mexico.,'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Mireya Orozco-Vela
- 'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Uriel Francisco Santana-Bejarano
- 'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Elizabeth Torres-Anguiano
- 'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
| | - Manuela Pinto-Cardoso
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal
| | - Dezső David
- Department of Human Genetics, National Health Institute Doutor Ricardo Jorge, Lisbon, Portugal
| | - Lucina Bobadilla-Morales
- Center for Registry and Research on Congenital Anomalies (CRIAC), Service of Genetics and Cytogenetics Unit, Division of Pediatrics, "Dr. Juan I. Menchaca" Civil Hospital of Guadalajara, Guadalajara, Mexico.,'Dr. Enrique Corona-Rivera' Institute of Human Genetics, Department of Molecular Biology and Genomics, Health Sciences University Center, University of Guadalajara, Guadalajara, Mexico
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