1
|
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.
Collapse
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.
| |
Collapse
|
4
|
Lesieur-Sebellin M, Till M, Khau Van Kien P, Herve B, Bourgon N, Dupont C, Tabet AC, Barrois M, Coussement A, Loeuillet L, Mousty E, Ea V, El Assal A, Mary L, Jaillard S, Beneteau C, Le Vaillant C, Coutton C, Devillard F, Goumy C, Delabaere A, Redon S, Laurent Y, Lamouroux A, Massardier J, Turleau C, Sanlaville D, Cantagrel V, Sonigo P, Vialard F, Salomon LJ, Malan V. Terminal 6q deletions cause brain malformations, a phenotype mimicking heterozygous DLL1 pathogenic variants: A multicenter retrospective case series. Prenat Diagn 2021; 42:118-135. [PMID: 34894355 DOI: 10.1002/pd.6074] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 11/24/2021] [Accepted: 11/30/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Terminal 6q deletion is a rare genetic condition associated with a neurodevelopmental disorder characterized by intellectual disability and structural brain anomalies. Interestingly, a similar phenotype is observed in patients harboring pathogenic variants in the DLL1 gene. Our study aimed to further characterize the prenatal phenotype of this syndrome as well as to attempt to establish phenotype-genotype correlations. METHOD We collected ultrasound findings from 22 fetuses diagnosed with a pure 6qter deletion. We reviewed the literature and compared our 22 cases with 14 fetuses previously reported as well as with patients with heterozygous DLL1 pathogenic variants. RESULTS Brain structural alterations were observed in all fetuses. The most common findings (>70%) were cerebellar hypoplasia, ventriculomegaly, and corpus callosum abnormalities. Gyration abnormalities were observed in 46% of cases. Occasional findings included cerebral heterotopia, aqueductal stenosis, vertebral malformations, dysmorphic features, and kidney abnormalities. CONCLUSION This is the first series of fetuses diagnosed with pure terminal 6q deletion. Based on our findings, we emphasize the prenatal sonographic anomalies, which may suggest the syndrome. Furthermore, this study highlights the importance of chromosomal microarray analysis to search for submicroscopic deletions of the 6q27 region involving the DLL1 gene in fetuses with these malformations.
Collapse
Affiliation(s)
- Marion Lesieur-Sebellin
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Faculté de Médecine, Sorbonne Université, Paris, France
| | - Marianne Till
- Laboratoire de Cytogénétique, service de Génétique, Hospices Civils de Lyon, Groupement Hospitalier Est, Bron, France
| | | | - Bérénice Herve
- Département de Génétique, CHI Poissy Saint-Germain, Saint-Germain, France
- Université Paris-Saclay, UVSQ, INRAE, BREED, Jouy-en-Josas, France
| | - Nicolas Bourgon
- Service d'Obstétrique et de Médecine Fœtale, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Céline Dupont
- Département de Génétique, Unité de Cytogénétique, Hôpital Robert Debré, APHP Nord, Paris, France
| | - Anne-Claude Tabet
- Département de Génétique, Unité de Cytogénétique, Hôpital Robert Debré, APHP Nord, Paris, France
- Génétique Humaine et Fonctions Cognitives, Institut Pasteur, UMR3571 CNRS, Université de Paris, Paris, France
| | - Mathilde Barrois
- Maternité Port Royal, APHP Centre, Hôpital Cochin, Paris, France
| | - Aurélie Coussement
- Service des Maladies Génétiques de système et d'organes, APHP-Centre, Hôpital Cochin, Paris, France
| | - Laurence Loeuillet
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Eve Mousty
- Service de Gynécologie Obstétrique, Hôpital Caremeau, Nîmes, France
| | - Vuthy Ea
- UF de Cytogénétique et Génétique Médicale, Hôpital Caremeau, Nîmes, France
| | - Amal El Assal
- Département de Gynécologie Obstétrique, CHI Poissy Saint-Germain, Saint-Germain, France
| | - Laura Mary
- Service d'Anatomie Pathologique, CHU Rennes, Rennes, France
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
| | - Sylvie Jaillard
- Service de Cytogénétique et Biologie Cellulaire, CHU Rennes, Rennes, France
- INSERM, EHESP, IRSET, Université Rennes 1, Rennes, France
| | - Claire Beneteau
- Service de Génétique Médicale, CHU Nantes, Nantes, France
- UF de Fœtopathologie et Génétique, CHU de Nantes, Nantes, France
| | | | - Charles Coutton
- Service de Génétique, Génomique et Procréation, Hôpital Couple Enfant, CHU Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institut pour l'Avancée des Biosciences, Equipe Génétique, Epigénétique et Thérapies de l'infertilité, Grenoble, France
| | - Françoise Devillard
- Service de Génétique, Génomique et Procréation, Hôpital Couple Enfant, CHU Grenoble Alpes, Grenoble, France
| | - Carole Goumy
- Cytogénétique Médicale, CHU Clermont-Ferrand, CHU Estaing, Université Clermont Auvergne, INSERM, U1240 Imagerie Moléculaire et Stratégies Théranostiques, Clermont-Ferrand, France
| | | | - Sylvia Redon
- CHU Brest, Inserm, Université de Brest, Brest, France
| | - Yves Laurent
- Service de Gynécologie et Obstétrique, GHBS Lorient, Lorient, France
| | - Audrey Lamouroux
- Service de Génétique Clinique, CHU Montpellier, Université de Montpellier, Montpellier, France
- Service de Gynécologie Obstétrique, CHU Nîmes, Université de Montpellier, Nîmes, France
| | - Jérôme Massardier
- Service de Gynécologie et Obstétrique, Hôpital Femme-Mère-Enfant, Hospices Civils de Lyon, Bron, France
| | - Catherine Turleau
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - Damien Sanlaville
- Laboratoire de Cytogénétique, service de Génétique, Hospices Civils de Lyon, Groupement Hospitalier Est, Bron, France
| | - Vincent Cantagrel
- Université de Paris, Institut Imagine, Laboratoire de génétique des troubles du neurodéveloppement, Paris, France
- Université de Paris, Paris, France
| | - Pascale Sonigo
- Service de Radiologie Pédiatrique, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
| | - François Vialard
- Département de Génétique, CHI Poissy Saint-Germain, Saint-Germain, France
- Université Paris-Saclay, UVSQ, INRAE, BREED, Jouy-en-Josas, France
| | - Laurent J Salomon
- Service d'Obstétrique et de Médecine Fœtale, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Université de Paris, Paris, France
| | - Valérie Malan
- Service de Médecine Génomique des Maladies Rares, APHP-Centre, Hôpital Necker-Enfants Malades, Paris, France
- Université de Paris, Institut Imagine, Laboratoire de génétique des troubles du neurodéveloppement, Paris, France
- Université de Paris, Paris, France
| |
Collapse
|
5
|
Stern S, Hacohen N, Meiner V, Yagel S, Zenvirt S, Shkedi-Rafid S, Macarov M, Valsky DV, Porat S, Yanai N, Frumkin A, Daum H. Universal chromosomal microarray analysis reveals high proportion of copy-number variants in low-risk pregnancies. ULTRASOUND IN OBSTETRICS & GYNECOLOGY : THE OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY OF ULTRASOUND IN OBSTETRICS AND GYNECOLOGY 2021; 57:813-820. [PMID: 32202684 DOI: 10.1002/uog.22026] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/12/2020] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
OBJECTIVES To evaluate the yield and utility of the routine use of chromosomal microarray analysis (CMA) for prenatal genetic diagnosis in a large cohort of pregnancies with normal ultrasound (US) at the time of genetic testing, compared with pregnancies with abnormal US findings. METHODS We reviewed all prenatal CMA results in our center between November 2013 and December 2018. The prevalence of different CMA results in pregnancies with normal US at the time of genetic testing ('low-risk pregnancies'), was compared with that in pregnancies with abnormal US findings ('high-risk pregnancies'). Medical records were searched in order to evaluate subsequent US follow-up and the outcome of pregnancies with a clinically relevant copy-number variant (CNV), i.e. a pathogenic or likely pathogenic CNV or a susceptibility locus for disease with > 10% penetrance, related to early-onset disease in the low-risk group. RESULTS In a cohort of 6431 low-risk pregnancies that underwent CMA, the prevalence of a clinically significant CNV related to early-onset disease was 1.1% (72/6431), which was significantly lower than the prevalence in high-risk pregnancies (4.9% (65/1326)). Of the low-risk pregnancies, 0.4% (27/6431) had a pathogenic or likely pathogenic CNV, and another 0.7% (45/6431) had a susceptibility locus with more than 10% penetrance. Follow-up of the low-risk pregnancies with a clinically significant early-onset CNV revealed that 31.9% (23/72) were terminated, while outcome data were missing in 26.4% (19/72). In 16.7% (12/72) of low-risk pregnancies, an US abnormality was discovered later on in gestation, after genetic testing had been performed. CONCLUSION Although the background risk of identifying a clinically significant early-onset abnormal CMA result in pregnancies with a low a-priori risk is lower than that observed in high-risk pregnancies, the risk is substantial and should be conveyed to all pregnant women. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.
Collapse
Affiliation(s)
- S Stern
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - N Hacohen
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - V Meiner
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Yagel
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Zenvirt
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Shkedi-Rafid
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - M Macarov
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - D V Valsky
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - S Porat
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - N Yanai
- Department of Obstetrics and Gynecology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - A Frumkin
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - H Daum
- Department of Genetics, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| |
Collapse
|
6
|
Hanna MD, Moretti PN, P de Oliveira C, A Rosa MT, R Versiani B, de Oliveira SF, Pic-Taylor A, F Mazzeu J. Defining the Critical Region for Intellectual Disability and Brain Malformations in 6q27 Microdeletions. Mol Syndromol 2019; 10:202-208. [PMID: 31602192 DOI: 10.1159/000501008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/07/2019] [Indexed: 11/19/2022] Open
Abstract
Terminal microdeletions of the long arm of chromosome 6 are associated with a phenotype that includes multiple brain malformations, intellectual disability, and epilepsy. A 1.7-Mb region has been proposed to contain a gene responsible for the brain anomalies. Here, we present the case of a 12-year-old girl with multiple brain alterations and moderate intellectual disability with a 18-kb deletion in chromosome 6q27, which is smaller than the microdeletions previously described by microarray analysis. We refined the smallest region of overlap possibly associated with the phenotype of brain malformations and intellectual disability to a segment of 325 kb, comprising the DLL1, PSMB1, TBP, and PDCD2 genes since these genes were structurally and/or functionally lost in the smaller deletions described to date. We hypothesize that DLL1 is responsible for brain malformations and possibly interacts with other adjacent genes. The TBP gene encodes a transcription factor which is potentially related to cognitive development. TBP is linked to PSMB1 and PDCD2 in a conserved manner among mammals, suggesting a potential interaction between these genes. In conclusion, the 6q27 microdeletion is a complex syndrome with variable expressivity of brain malformations and intellectual disability phenotypes which are possibly triggered by the 4 genes described and adjacent genes susceptible to gene regulation changes.
Collapse
Affiliation(s)
- Marcela D Hanna
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | | | | | - Maria T A Rosa
- Secretaria de Estado de Saúde do Distrito Federal, Brasília, Brazil
| | - Beatriz R Versiani
- Hospital Universitário de Brasília, Universidade de Brasília, Brasília, Brazil
| | - Silviene F de Oliveira
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Aline Pic-Taylor
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Departamento de Genética e Morfologia, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, Brazil
| | - Juliana F Mazzeu
- Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Ciências da Saúde, Universidade de Brasília, Brasília, Brazil.,Faculdade de Medicina, Universidade de Brasília, Brasília, Brazil
| |
Collapse
|