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Dubucs C, Chassaing N, Sergi C, Aubert-Mucca M, Attié-Bitach T, Lacombe D, Thauvin-Robinet C, Arpin S, Perez MJ, Cabrol C, Chen CP, Aziza J, Colin E, Martinovic J, Calvas P, Plaisancié J. Re-focusing on Agnathia-Otocephaly complex. Clin Oral Investig 2020; 25:1353-1362. [PMID: 32643087 DOI: 10.1007/s00784-020-03443-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 07/03/2020] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Agnathia-otocephaly complex is a rare condition characterized by mandibular hypoplasia or agnathia, ear anomalies (melotia/synotia) and microstomia with aglossia. This severe anomaly of the first branchial arch is most often lethal. The estimated incidence is less than 1 in 70.000 births, with etiologies linked to both genetic and teratogenic factors. Most of the cases are sporadic. To date, two genes have been described in humans to be involved in this condition: OTX2 and PRRX1. Nevertheless, the overall proportion of mutated cases is unknown and a significant number of patients remain without molecular diagnosis. Thus, the involvement of other genes than OTX2 and PRRX1 in the agnathia-otocephaly complex is not unlikely. Heterozygous mutations in Cnbp in mice are responsible for mandibular and eye defects mimicking the agnathia-otocephaly complex in humans and appear as a good candidate. Therefore, in this study, we aimed (i) to collect patients presenting with agnathia-otocephaly complex for screening CNBP, in parallel with OTX2 and PRRX1, to check its possible implication in the human phenotype and (ii) to compare our results with the literature data to estimate the proportion of mutated cases after genetic testing. MATERIALS AND METHODS In this work, we describe 10 patients suffering from the agnathia-otocephaly complex. All of them benefited from array-CGH and Sanger sequencing of OTX2, PRRX1 and CNBP. A complete review of the literature was made using the Pubmed database to collect all the patients described with a phenotype of agnathia-otocephaly complex during the 20 last years (1998-2019) in order (i) to study etiology (genetic causes, iatrogenic causes…) and (ii), when genetic testing was performed, to study which genes were tested and by which type of technologies. RESULTS In our 10 patients' cohort, no point mutation in the three tested genes was detected by Sanger sequencing, while array-CGH has allowed identifying a 107-kb deletion encompassing OTX2 responsible for the agnathia-otocephaly complex phenotype in 1 of them. In 4 of the 70 cases described in the literature, a toxic cause was identified and 22 out the 66 remaining cases benefited from genetic testing. Among those 22 patients, 6 were carrying mutation or deletion in the OTX2 gene and 4 in the PRRX1 gene. Thus, when compiling results from our cohort and the literature, a total of 32 patients benefited from genetic testing, with only 34% (11/32) of patients having a mutation in one of the two known genes, OTX2 or PRRX1. CONCLUSIONS From our work and the literature review, only mutations in OTX2 and PRRX1 have been found to date in patients, explaining around one third of the etiologies after genetic testing. Thus, agnathia-otocephaly complex remains unexplained in the majority of the patients, which indicates that other factors might be involved. Although involved in first branchial arch defects, no mutation in the CNBP gene was found in this study. This suggests that mutations in CNBP might not be involved in such phenotype in humans or that, unlike in mice, a compensatory effect might exist in humans. Nevertheless, given that agnathia-otocephaly complex is a rare phenotype, more patients have to be screened for CNBP mutations before we definitively conclude about its potential implication. Therefore, this work presents the current state of knowledge on agnathia-otocephaly complex and underlines the need to expand further the understanding of the genetic bases of this disorder, which remains largely unknown. CLINICAL RELEVANCE We made here an update and focus on the clinical and genetic aspects of agnathia-otocephaly complex as well as a more general review of craniofacial development.
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Affiliation(s)
- C Dubucs
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France.,Département d'Anatomie et de Cytologie Pathologiques, Institut Universitaire du cancer de Toulouse, Toulouse, France
| | - N Chassaing
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France.,INSERM U1056, Université Toulouse III, Toulouse, France
| | - C Sergi
- Department of Lab. Med. & Pathology (5B4.09), University of Alberta, Edmonton, AB, Canada
| | - M Aubert-Mucca
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France
| | - T Attié-Bitach
- Unité d'Embryofœtopathologie, Service d'Histologie Embryologie Cytogénétique, Hôpital Necker-Enfants Malades, Assistance Publique Hôpitaux de Paris (APHP), Paris, France.,Institut Imagine, INSERM U1163, Université Paris Descartes, Sorbonne Paris Cite, Paris, France
| | - D Lacombe
- Service de Génétique Médicale, CRMR, CHU de Bordeaux, Bordeaux, France.,INSERM U1211, Université de Bordeaux, 33076, Bordeaux, France
| | - C Thauvin-Robinet
- UMR1231 GAD, Inserm - Université Bourgogne-Franche Comté, Dijon, France.,Unité Fonctionnelle Innovation en Diagnostic génomique des maladies rares, FHU-TRANSLAD, CHU Dijon, Dijon, Bourgogne, France.,Centre de Référence maladies rares "Anomalies du Développement et syndromes malformatifs," Centre de Génétique, FHU-TRANSLAD, CHU Dijon Bourgogne, Dijon, France
| | - S Arpin
- Service de Génétique Clinique, Centre Hospitalier Régional Universitaire de Tours, Tours, France
| | - M J Perez
- Department of Medical Genetics, Reference Center for Developmental Abnormalities and Constitutional Bone Diseases, CHRU, Montpellier, France
| | - C Cabrol
- Centre de Génétique Humaine, Centre Hospitalier Universitaire, Université de Franche-Comté, Besançon, France
| | - C P Chen
- Department of Materials Engineering, Ming Chi University of Technology, New Taipei City, Taiwan
| | - J Aziza
- Département d'Anatomie et de Cytologie Pathologiques, Institut Universitaire du cancer de Toulouse, Toulouse, France
| | - E Colin
- Department de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France.,UMR CNRS 6214-INSERM 1083 and PREMMI, Université d'Angers, Angers, France
| | - J Martinovic
- Unit of Fetal Pathology, AP-HP Antoine Béclère Hospital, Clamart, France
| | - P Calvas
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France.,INSERM U1056, Université Toulouse III, Toulouse, France
| | - Julie Plaisancié
- Service de Génétique Médicale, Hôpital Purpan, CHU Toulouse, Toulouse, France. .,INSERM U1056, Université Toulouse III, Toulouse, France.
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Summers AD, Reefhuis J, Taliano J, Rasmussen SA. Nongenetic risk factors for holoprosencephaly: An updated review of the epidemiologic literature. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:151-164. [PMID: 29761639 DOI: 10.1002/ajmg.c.31614] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 12/17/2022]
Abstract
Holoprosencephaly (HPE) is a major structural birth defect of the brain that occurs in approximately 1 in 10,000 live births. Although some genetic causes of HPE are known, a substantial proportion of cases have an unknown etiology. Due to the low birth prevalence and rarity of exposure to many potential risk factors for HPE, few epidemiologic studies have had sufficient sample size to examine risk factors. A 2010 review of the literature identified several risk factors that had been consistently identified as occurring more frequently among cases of HPE, including maternal diabetes, twinning, and a predominance of females, while also identifying a number of potential risk factors that had been less widely studied. In this article, we summarize a systematic literature review conducted to update the evidence for nongenetic risk factors for HPE.
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Affiliation(s)
- April D Summers
- Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Jennita Reefhuis
- Division of Congenital and Developmental Disorders, National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Joanna Taliano
- LAC Group, Contractor to US Centers for Disease Control and Prevention, Library Science Branch, Division of Public Health Information Dissemination, Center for Surveillance, Epidemiology, and Laboratory Services, Atlanta, Georgia
| | - Sonja A Rasmussen
- Office of Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia
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