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Saboori-Darabi S, Carrera P, Akbari A, Amiri-Yekta A, Almadani N, Battista Pipitone G, Shahrokh-Tehraninejad E, Lotfi M, Mazaheri M, Totonchi M. A heterozygous missense variant in DLX3 leads to uterine leiomyomas and pregnancy losses in a consanguineous Iranian family. Gene 2023; 865:147292. [PMID: 36854347 DOI: 10.1016/j.gene.2023.147292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 02/07/2023] [Accepted: 02/15/2023] [Indexed: 03/01/2023]
Abstract
Uterine leiomyomas (ULs) are benign solid tumors arising from the uterine myometrium. They are the most common pelvic tumors among females of reproductive age. Despite the universal prevalence of ULs and its huge impact on women's lives, the exact etiology and pathophysiologic mechanisms have not been fully understood. Numerous studies indicate that genetic factors play a crucial role in ULs development. This study aims to identify the probable genetic causes of ULs in a consanguineous Iranian family. Whole-exome sequencing (WES) on five family members with ULs revealed a likely pathogenic missense variant encoding for Y88C in the transactivation (TA) domain of DLX3 gene (c.263A > G; p.Y88C). Sanger sequencing of a total of 9 affected and non-affected family members indicated a segregation with disease with autosomal dominant inheritance. Moreover, targeted Sanger sequencing on 32 additional non-related patients with ULs showed none was heterozygous for this variant. MutPred2 predicted the pathogenicity of candidate variant by both phosphorylation and sulfation loss as actionable hypotheses. Project HOPE revealed that the identified variant residue is smaller and more hydrophobic comparing to the wild-type residue. I-TASSER and UCSF Chimera were also used for modeling and visualizing the predicted variant, respectively. This WES analysis is the first to report a variant in DLX3 variation associated with ULs pathogenicity in Iranian population highlighting the effectiveness of WES as a strong diagnostic method. However, further functional studies on this variant are needed to confirm the potential pathogenicity of this mutation.
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Affiliation(s)
- Samaneh Saboori-Darabi
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Paola Carrera
- Laboratory of Clinical Molecular Biology and Cytogenetics, IRCCS San Raffaele Hospital, Milan, Italy
| | - Arvand Akbari
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Amir Amiri-Yekta
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Navid Almadani
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | | | - Ensieh Shahrokh-Tehraninejad
- Department of Endocrinology and Female Infertility, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
| | - Marzieh Lotfi
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mahta Mazaheri
- Department of Medical Genetics, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran; Mother & Newborn Health Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
| | - Mehdi Totonchi
- Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran; School of Biological Science, Institute for Research in Fundamental Sciences (IPM), Tehran, Iran.
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"Isolated" Amelogenesis Imperfecta Associated with DLX3 Mutation: A Clinical Case. Case Rep Genet 2020; 2020:8217919. [PMID: 32832172 PMCID: PMC7424401 DOI: 10.1155/2020/8217919] [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: 01/24/2020] [Revised: 05/26/2020] [Accepted: 07/15/2020] [Indexed: 01/08/2023] Open
Abstract
Amelogenesis imperfecta (AI) represents rare tooth anomalies that affect the quality and/or quantity of the enamel. Clinical phenotypes display a wide spectrum, ranging from mild color changes to severe structural alterations with daily pain. However, all affect the quality of life because of mechanical, psychological, esthetic, and/or social repercussions. Several gene mutations have been linked to AI as a nonsyndromic (isolated) phenotype or a wider syndrome. This case report aimed to present a family with dental structure anomalies followed up in the dental department of the Louis Mourier Hospital (APHP, France) for their extremely poor dental condition. The proband and his mother were clinically diagnosed with AI, and genetic analysis revealed an already described variant in DLX3. Then, the family was further examined for tricho-dento-osseous syndrome. This report illustrates the challenge of diagnosing dental structure anomalies, specifically AI, in adults and highlights the need for an accurate and accessible molecular diagnosis for those anomalies to discriminate between isolated and syndromic pathologies.
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Shibano M, Watanabe A, Takano N, Mishima H, Kinoshita A, Yoshiura KI, Shibahara T. Target Capture/Next-Generation Sequencing for Nonsyndromic Cleft Lip and Palate in the Japanese Population. Cleft Palate Craniofac J 2019; 57:80-87. [PMID: 31337262 DOI: 10.1177/1055665619857650] [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] [Indexed: 02/02/2023] Open
Abstract
OBJECTIVE The pathogenesis of nonsyndromic cleft lip with or without cleft palate (NSCL ± P) and nonsyndromic cleft palate only (NSCP) may be associated with genetic factors. Although some predisposing genes/loci have been reported, their attributable risk is too small to be clinically meaningful. To clarify the genetic causes and mechanisms of NSCL±P or NSCP, we conducted mutation analysis of target genes using a next-generation sequencing (NGS) approach. METHODS The target genes, IRF6, WNT5A, WNT9B, TP63, MSX1, TFAP2A, PAX9, DLX3, DLX4, and MN1, were selected based on previous reports of potential associations with the development of NSCL±P or NSCP from genome-wide association studies and candidate gene analyses. Mutation analysis was conducted using NGS on 74 Japanese trios (patient and parents) and 18 Japanese patients only families. RESULTS We detected single-nucleotide variants (SNVs) for 7 genes: IRF6, DLX4, WNT5A, TFAP2A, WNT9B, TP63, and PAX9. The SNVs found on IRF6 and DLX4 were missense mutations, whereas those identified on WNT5A, TFAP2A, WNT9B, TP63, and PAX9 were rare variants in the noncoding region; no de novo mutation was identified in the trio samples. The amino acid change on DLX4 was detected within the highly conserved homeodomain and was predicted to have a deleterious impact on the protein function by in silico analysis. CONCLUSIONS The DLX4 missense mutation c.359C>T (Pro120Leu) was found in 1 Japanese patient with NSCL±P and was located in the homeodomain region. This mutation likely plays a role in the development of NSCL±P in the Japanese population.
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Affiliation(s)
- Masayasu Shibano
- Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Tokyo, Japan
| | - Akira Watanabe
- Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Tokyo, Japan
| | - Nobuo Takano
- Oral Cancer Center, Tokyo Dental College, Chiba, Japan
| | - Hiroyuki Mishima
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Akira Kinoshita
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Koh-Ichiro Yoshiura
- Department of Human Genetics, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan
| | - Takahiko Shibahara
- Department of Oral and Maxillofacial Surgery, Tokyo Dental College, Tokyo, Japan
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Lu T, Li M, Xu X, Xiong J, Huang C, Zhang X, Hu A, Peng L, Cai D, Zhang L, Wu B, Xiong F. Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders. Int J Oral Sci 2018; 10:26. [PMID: 30174330 PMCID: PMC6119682 DOI: 10.1038/s41368-018-0027-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/15/2018] [Accepted: 05/18/2018] [Indexed: 11/25/2022] Open
Abstract
Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named “amelin” or “sheathlin”) is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders. A mutation on a gene involved in healthy tooth development may cause both enamel and dentin disorders. The ameloblastin enamel protein, and its associated gene, AMBN, play vital roles in enamel formation and tooth remodelling. Mutations on AMBN can cause amelogenesis imperfecta (AI), a genetic and hereditory condition resulting in enamel defects and severe tooth decay. Now, Fu Xiong and Bu-Ling Wu at Southern Medical University in Guangzhou, China, and co-workers have identified an AMBN mutation found in both enamel and dentin defect disorders. The researchers analyzed extracted teeth from a Chinese patient with both AI and a severe dentin disorder, along with teeth from affected and non-affected members of the same family, and compared the results with a control group. They identified a rare mutation on AMBN common to all affected individuals.
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Affiliation(s)
- Ting Lu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.,Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Meiyi Li
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiangmin Xu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China.,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China
| | - Jun Xiong
- Department of Laboratory Medicine, ZhuJiang Hospital, Southern Medical University, Guangzhou, Guangdong, China
| | - Cheng Huang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Xuelian Zhang
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Aiqin Hu
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Ling Peng
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Decheng Cai
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China
| | - Leitao Zhang
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China
| | - Buling Wu
- Department of Stomatology, Nanfang Hospital, College of Stomatology, Southern Medical University, Guangzhou, Guangdong, China.
| | - Fu Xiong
- Department of Medical Genetics, School of Basic Medicine Sciences, Southern Medical University, Guangzhou, Guangdong, China. .,Guangdong Key Laboratory of Biological Chip, Guangzhou, Guangdong, China.
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Kastovsky J, Borilova Linhartova P, Musilova K, Zackova L, Kukletova M, Kukla L, Izakovicova Holla L. Lack of Association between BMP2/DLX3 Gene Polymorphisms and Dental Caries in Primary and Permanent Dentitions. Caries Res 2017; 51:590-595. [PMID: 29059672 DOI: 10.1159/000479828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 07/26/2017] [Indexed: 01/24/2023] Open
Abstract
The aim of this study was to analyze the association between BMP2 (rs1884302) and DLX3 (rs2278163) gene polymorphisms and dental caries in primary and permanent dentitions. A total of 914 subjects were genotyped by the TaqMan methods: 176 caries-free children (with Decayed/Missing/Filled Teeth, DMFT = 0), 542 patients with dental caries in permanent dentition (DMFT ≥1), 83 caries-free children with primary teeth (with decayed/missing/filled teeth, dmft = 0), and 113 children with early childhood caries (ECC, dmft ≥1). There were no significant differences in allele/genotype frequencies between patients with caries in permanent dentition/ECC and caries-free children or between patients with very low (DMFT = 0-2), low (DMFT = 3-5), moderate (DMFT = 6-8), or high (DMFT ≥9) caries experience. Variability in BMP2 and DLX3 was not associated with caries in the Czech population.
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Smith CEL, Poulter JA, Antanaviciute A, Kirkham J, Brookes SJ, Inglehearn CF, Mighell AJ. Amelogenesis Imperfecta; Genes, Proteins, and Pathways. Front Physiol 2017; 8:435. [PMID: 28694781 PMCID: PMC5483479 DOI: 10.3389/fphys.2017.00435] [Citation(s) in RCA: 153] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 06/08/2017] [Indexed: 01/11/2023] Open
Abstract
Amelogenesis imperfecta (AI) is the name given to a heterogeneous group of conditions characterized by inherited developmental enamel defects. AI enamel is abnormally thin, soft, fragile, pitted and/or badly discolored, with poor function and aesthetics, causing patients problems such as early tooth loss, severe embarrassment, eating difficulties, and pain. It was first described separately from diseases of dentine nearly 80 years ago, but the underlying genetic and mechanistic basis of the condition is only now coming to light. Mutations in the gene AMELX, encoding an extracellular matrix protein secreted by ameloblasts during enamel formation, were first identified as a cause of AI in 1991. Since then, mutations in at least eighteen genes have been shown to cause AI presenting in isolation of other health problems, with many more implicated in syndromic AI. Some of the encoded proteins have well documented roles in amelogenesis, acting as enamel matrix proteins or the proteases that degrade them, cell adhesion molecules or regulators of calcium homeostasis. However, for others, function is less clear and further research is needed to understand the pathways and processes essential for the development of healthy enamel. Here, we review the genes and mutations underlying AI presenting in isolation of other health problems, the proteins they encode and knowledge of their roles in amelogenesis, combining evidence from human phenotypes, inheritance patterns, mouse models, and in vitro studies. An LOVD resource (http://dna2.leeds.ac.uk/LOVD/) containing all published gene mutations for AI presenting in isolation of other health problems is described. We use this resource to identify trends in the genes and mutations reported to cause AI in the 270 families for which molecular diagnoses have been reported by 23rd May 2017. Finally we discuss the potential value of the translation of AI genetics to clinical care with improved patient pathways and speculate on the possibility of novel treatments and prevention strategies for AI.
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Affiliation(s)
- Claire E L Smith
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - James A Poulter
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Agne Antanaviciute
- Section of Genetics, School of Medicine, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Jennifer Kirkham
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Steven J Brookes
- Division of Oral Biology, School of Dentistry, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom
| | - Alan J Mighell
- Section of Ophthalmology and Neuroscience, St. James's University Hospital, University of LeedsLeeds, United Kingdom.,Oral Medicine, School of Dentistry, University of LeedsLeeds, United Kingdom
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Gasse B, Prasad M, Delgado S, Huckert M, Kawczynski M, Garret-Bernardin A, Lopez-Cazaux S, Bailleul-Forestier I, Manière MC, Stoetzel C, Bloch-Zupan A, Sire JY. Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta. Front Physiol 2017; 8:398. [PMID: 28659819 PMCID: PMC5469888 DOI: 10.3389/fphys.2017.00398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/26/2017] [Indexed: 12/21/2022] Open
Abstract
Amelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI.
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Affiliation(s)
- Barbara Gasse
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
| | - Megana Prasad
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France
| | - Sidney Delgado
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
| | - Mathilde Huckert
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France.,Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France
| | - Marzena Kawczynski
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France
| | - Annelyse Garret-Bernardin
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Unit of Dentistry, IRCCS, Bambino Gesù Children's HospitalRome, Italy
| | - Serena Lopez-Cazaux
- Faculté de Chirurgie Dentaire, Département d'Odontologie Pédiatrique, Centre de Compétences Maladies Rares, CHU Hôtel Dieu, Service d'odontologie Conservatrice et PédiatriqueNantes, France
| | - Isabelle Bailleul-Forestier
- Faculté de Chirurgie Dentaire, CHU de Toulouse, Centre de Compétences Maladies Rares, Odontologie Pédiatrique, Université Paul SabatierToulouse, France
| | - Marie-Cécile Manière
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, Institut National de la Santé et de la Recherche Médicale UMRS_1112, Institut de Génétique Médicale d'Alsace, FMTS, Université de StrasbourgStrasbourg, France
| | - Agnès Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université de StrasbourgStrasbourg, France.,Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, O-Rares, Hôpitaux Universitaires de StrasbourgStrasbourg, France.,Centre Européen de Recherche en Biologie et en Médecine, Centre National de la Recherche Scientifique UMR7104, Institut National de la Santé et de la Recherche Médicale U964, Institut de Génétique et de Biologie Moléculaire and Cellulaire, Université de StrasbourgIllkirch, France.,Institut d'Etudes Avancées, Université de Strasbourg, USIASStrasbourg, France.,Eastman Dental Institute, University College LondonLondon, United Kingdom
| | - Jean-Yves Sire
- Institut de Biologie Paris-Seine, UMR 7138-Evolution Paris-Seine, Sorbonne Universités, Université Pierre et Marie CurieParis, France
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Lignon G, Beres F, Quentric M, Rouzière S, Weil R, De La Dure-Molla M, Naveau A, Kozyraki R, Dessombz A, Berdal A. FAM20A Gene Mutation: Amelogenesis or Ectopic Mineralization? Front Physiol 2017; 8:267. [PMID: 28515694 PMCID: PMC5413562 DOI: 10.3389/fphys.2017.00267] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/11/2017] [Indexed: 12/12/2022] Open
Abstract
Background and objective:FAM20A gene mutations result in enamel renal syndrome (ERS) associated with amelogenesis imperfecta (AI), nephrocalcinosis, gingival fibromatosis, and impaired tooth eruption. FAM20A would control the phosphorylation of enamel peptides and thus enamel mineralization. Here, we characterized the structure and chemical composition of unerupted tooth enamel from ERS patients and healthy subjects. Methods: Tooth sections were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF). Results: SEM revealed that prisms were restricted to the inner-most enamel zones. The bulk of the mineralized matter covering the crown was formed by layers with varying electron-densities organized into lamellae and micronodules. Tissue porosity progressively increased at the periphery, ending with loose and unfused nanonodules also observed in the adjoining soft tissues. Thus, the enamel layer covering the dentin in all ERS patients (except a limited layer of enamel at the dentino-enamel junction) displayed an ultrastructural globular pattern similar to one observed in ectopic mineralization of soft tissue, notably in the gingiva of Fam20a knockout mice. XRD analysis confirmed the existence of alterations in crystallinity and composition (vs. sound enamel). XRF identified lower levels of calcium and phosphorus in ERS enamel. Finally, EDS confirmed the reduced amount of calcium in ERS enamel, which appeared similar to dentin. Conclusion: This study suggests that, after an initial normal start to amelogenesis, the bulk of the tissue covering coronal dentin would be formed by different mechanisms based on nano- to micro-nodule aggregation. This evocated ectopic mineralization process is known to intervene in several soft tissues in FAM20A gene mutant.
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Affiliation(s)
- Guilhem Lignon
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Fleur Beres
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Mickael Quentric
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Stephan Rouzière
- Laboratoire de Physique des Solides, Centre National de la Recherche Scientifique, Univ. Paris-Sud, Université Paris-SaclayOrsay Cedex, France
| | - Raphael Weil
- Laboratoire de Physique des Solides, Centre National de la Recherche Scientifique, Univ. Paris-Sud, Université Paris-SaclayOrsay Cedex, France
| | - Muriel De La Dure-Molla
- Reference Center of Rare Buccal and Facial Malformations MAFACE-Rothschild Hospital, APHPParis, France
| | - Adrien Naveau
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Renata Kozyraki
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Arnaud Dessombz
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Ariane Berdal
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France.,Reference Center of Rare Buccal and Facial Malformations MAFACE-Rothschild Hospital, APHPParis, France
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