1
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Yang Y, Qin M, Zhao Y, Wang X. Digenic inheritance accounts for phenotypic variability in amelogenesis imperfecta. Clin Genet 2024; 105:243-253. [PMID: 37937686 DOI: 10.1111/cge.14449] [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: 07/27/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/09/2023]
Abstract
Amelogenesis imperfecta (AI) represents a group of clinically and genetically heterogeneous disorders that affect enamel formation and mineralization. Although AI is commonly considered a monogenic disorder, digenic inheritance is rarely reported. In this study, we recruited two nonconsanguineous Chinese families exhibiting diverse phenotypes of enamel defects among affected family members. Digenic variants were discovered in both probands. In family 1, the proband inherited a paternal frameshift variant in LAMA3 (NM_198129.4:c.3712dup) and a maternal deletion encompassing the entire AMELX gene. This resulted in a combined hypoplastic and hypomineralized AI phenotype, which was distinct from the parents' manifestations. In family 2, whole-exome sequencing analysis revealed the proband carried a maternal heterozygous splicing variant in COL17A1 (NC_000010.11 (NM_000494.3): c.4156 + 2dup) and compound heterozygous variants in RELT (paternal: NM_032871.4:c.260A > T; maternal: NM_032871.4:c.521 T > G). These genetic changes caused the abundant irregular enamel defects observed in the proband, whereas other affected family members carrying heterozygous variants in both COL17A1 and RELT displayed only horizontal grooves as their phenotype. The pathogenicity of the novel COL17A1 splice site variant was confirmed through RT-PCR and minigene assay. This study enhances our understanding by highlighting the potential association between the co-occurrence of variants in two genes and variable phenotypes observed in AI patients.
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Affiliation(s)
- Yi Yang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Yuming Zhao
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
| | - Xin Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, People's Republic of China
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2
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Wang SK, Zhang H, Wang YL, Seymen F, Koruyucu M, Simmer JP, Hu JCC. Phenotypic variability in LAMA3-associated amelogenesis imperfecta. Oral Dis 2023; 29:3514-3524. [PMID: 36326426 PMCID: PMC10154430 DOI: 10.1111/odi.14425] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/04/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Amelogenesis imperfecta (AI) is defined as inherited enamel malformations. LAMA3 (laminin alpha-3) encodes a critical protein component of the basement membrane (laminin-332). Individuals carrying heterozygous LAMA3 mutations have previously been shown to have localized enamel defects. This study aimed to define clinical phenotypes and to discern the genetic etiology for four AI kindreds. MATERIALS AND METHODS Whole-exome analyses were conducted to search for sequence variants associated with the disorder, and micro-computed tomography (μCT) to characterize the enamel defects. RESULTS The predominant enamel phenotype was generalized thin enamel with defective pits and grooves. Horizonal bands of hypoplastic enamel with chalky-white discoloration and enamel hypomineralization were also observed and demonstrated by μCT analyses of affected teeth. Four disease-causing LAMA3 mutations (NM_198129.4:c.3712dup; c.5891dup; c.7367del; c.9400G > C) were identified. Compound heterozygous MMP20 mutations (NM_004771.4:c.539A > G; c.692C > T) were also found in one proband with more severe enamel defects, suggesting a mutational synergism on disease phenotypes. Further analyses of the AI-causing mutations suggested that both α3A (short) and α3B (long) isoforms of LAMA3 are essential for enamel formation. CONCLUSIONS Heterozygous LAMA3 mutations can cause generalized enamel defects (AI1A) with variable expressivity. Laminin-332 is critical not only for appositional growth but also enamel maturation.
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Affiliation(s)
- Shih-Kai Wang
- Department of Dentistry, National Taiwan University School of Dentistry, No.1, Changde St., Taipei City 100, Taiwan
- Department of Pediatric Dentistry, National Taiwan University Children’s Hospital, No.8, Zhongshan S. Rd., Taipei City 100, Taiwan
| | - Hong Zhang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI 48108, USA
| | - Yin-Lin Wang
- Department of Dentistry, National Taiwan University School of Dentistry, No.1, Changde St., Taipei City 100, Taiwan
- Department of Pediatric Dentistry, National Taiwan University Children’s Hospital, No.8, Zhongshan S. Rd., Taipei City 100, Taiwan
| | - Figen Seymen
- Department of Pedodontics, Faculty of Dentistry, Altinbas University, Istanbul, 34147, Turkey
| | - Mine Koruyucu
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, 34116, Turkey
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI 48108, USA
| | - Jan C.-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 North University, Ann Arbor, MI 48108, USA
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3
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Kotalevskaya YY, Stepanov VA. Molecular genetic basis of epidermolysis bullosa. Vavilovskii Zhurnal Genet Selektsii 2023; 27:18-27. [PMID: 36923479 PMCID: PMC10009482 DOI: 10.18699/vjgb-23-04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/10/2022] [Accepted: 12/20/2022] [Indexed: 03/11/2023] Open
Abstract
Epidermolysis bullosa (EB) is an inherited disorder of skin fragility, caused by mutations in a large number of genes associated with skin integrity and dermal-epidermal adhesion. Skin fragility is manifested by a decrease in resistance to external mechanical influences, the clinical signs of which are the formation of blisters, erosions and wounds on the skin and mucous membranes. EB is a multisystemic disease and characterized by a wide phenotypic spectrum with extracutaneous complications in severe types, besides the skin and mucous membranes, with high mortality. More than 30 clinical subtypes have been identified, which are grouped into four main types: simplex EB, junctional EB, dystrophic EB and Kindler syndrome. To date, pathogenic variants in 16 different genes are associated with EB and encode proteins that are part of the skin anchoring structures or are signaling proteins. Genetic mutations cause dysfunction of cellular structures, differentiation, proliferation and apoptosis of cells, leading to mechanical instability of the skin. The formation of reduced proteins or decrease in their level leads mainly to functional disorders, forming mild or intermediate severe phenotypes. Absent protein expression is a result of null genetic variants and leads to structural abnormalities, causing a severe clinical phenotype. For most of the genes involved in the pathogenesis of EB, certain relationships have been established between the type and position of genetic variant and the severity of the clinical manifestations of the disease. Establishing an accurate diagnosis depends on the correlation of clinical, genealogical and immunohistological data in combination with molecular genetic testing. In general, the study of clinical, genetic and ultrastructural changes in EB has significantly expanded the understanding of the natural history of the disease and supplemented the data on genotype-phenotype correlations, promotes the search and study of epigenetic and non-genetic disease modifier factors, and also allows developing approaches to radical treatment of the disease. New advances of sequencing technologies have made it possible to describe new phenotypes and study their genetic and molecular mechanisms. This article describes the pathogenetic aspects and genes that cause main and rare syndromic subtypes of EB.
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Affiliation(s)
- Yu Yu Kotalevskaya
- Moscow Regional Research and Clinical Institute, Moscow, Russia Charitable Foundation "BELA. Butterfly Children", Moscow, Russia
| | - V A Stepanov
- Research Institute of Medical Genetics, Tomsk National Research Medical Center of the Russian Academy of Sciences, Tomsk, Russia
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4
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Dąbrowska J, Biedziak B, Szponar-Żurowska A, Budner M, Jagodziński PP, Płoski R, Mostowska A. Identification of novel susceptibility genes for non-syndromic cleft lip with or without cleft palate using NGS-based multigene panel testing. Mol Genet Genomics 2022; 297:1315-1327. [PMID: 35778651 DOI: 10.1007/s00438-022-01919-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 06/12/2022] [Indexed: 01/02/2023]
Abstract
For non-syndromic cleft lip with or without cleft palate (ns-CL/P), the proportion of heritability explained by the known risk loci is estimated to be about 30% and is captured mainly by common variants identified in genome-wide association studies. To contribute to the explanation of the "missing heritability" problem for orofacial clefts, a candidate gene approach was taken to investigate the potential role of rare and private variants in the ns-CL/P risk. Using the next-generation sequencing technology, the coding sequence of a set of 423 candidate genes was analysed in 135 patients from the Polish population. After stringent multistage filtering, 37 rare coding and splicing variants of 28 genes were identified. 35% of these genetic alternations that may play a role of genetic modifiers influencing an individual's risk were detected in genes not previously associated with the ns-CL/P susceptibility, including COL11A1, COL17A1, DLX1, EFTUD2, FGF4, FGF8, FLNB, JAG1, NOTCH2, SHH, WNT5A and WNT9A. Significant enrichment of rare alleles in ns-CL/P patients compared with controls was also demonstrated for ARHGAP29, CHD7, COL17A1, FGF12, GAD1 and SATB2. In addition, analysis of panoramic radiographs of patients with identified predisposing variants may support the hypothesis of a common genetic link between orofacial clefts and dental abnormalities. In conclusion, our study has confirmed that rare coding variants might contribute to the genetic architecture of ns-CL/P. Since only single predisposing variants were identified in novel cleft susceptibility genes, future research will be required to confirm and fully understand their role in the aetiology of ns-CL/P.
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Affiliation(s)
- Justyna Dąbrowska
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781, Poznan, Poland
| | - Barbara Biedziak
- Department of Orthodontics and Craniofacial Anomalies, Poznan University of Medical Sciences, Poznan, Poland
| | - Anna Szponar-Żurowska
- Department of Orthodontics and Craniofacial Anomalies, Poznan University of Medical Sciences, Poznan, Poland
| | - Margareta Budner
- Eastern Poland Burn Treatment and Reconstructive Center, Leczna, Poland
| | - Paweł P Jagodziński
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781, Poznan, Poland
| | - Rafał Płoski
- Department of Medical Genetics, Warsaw Medical University, Warsaw, Poland
| | - Adrianna Mostowska
- Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, 6 Swiecickiego Street, 60-781, Poznan, Poland.
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5
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Urzúa B, Krämer S, Morales-Bozo I, Camacho C, Yubero MJ, Palisson F, Fuentes I, Ortega-Pinto A. Case Report: Crown Resorption in a Patient With Junctional Epidermolysis Bullosa and Amelogenesis Imperfecta With LAMB3 Gene Mutations. FRONTIERS IN DENTAL MEDICINE 2021. [DOI: 10.3389/fdmed.2021.704423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background: Epidermolysis bullosa (EB) corresponds to a series of conditions characterized by extreme fragility of the skin and/or mucous membranes. Of the four main types of EB, junctional EB (JEB) is the most associated with alterations in the teeth. The purposes of this study were to determine the clinical, histopathological, and ultrastructural characteristics of teeth with amelogenesis imperfecta (AI) in a patient with JEB, and compare them with control teeth, and correlate the findings with the mutations present in the patient.Case Report: The study was conducted on a 10-year-old patient with JEB carrier of two recessive mutations in the LAMB3 gene and absence of the laminin-332 protein (LM-332), determined by immunofluorescence on a skin biopsy. The patient presents hypoplastic AI with very thin and yellow-brown colored enamel. Extraction of two permanent molars was performed due to pain and soft tissue covering the crown, resembling pulp polyp or hyperplastic gingiva. Light and scanning electron microscopy (SEM) revealed very thin enamel varying from complete absence to 60 μm, absence of normal prismatic structure, and presence of a cross-banding with a laminated appearance. The histopathological study revealed granulation tissue causing external crown resorption.Conclusion: Although coronary resorption has been reported in patients with syndromic and non-syndromic AI, this is the first clinicopathological report of coronary resorption in partially erupted teeth in patients with JEB with mutations in the LAMB3 gene and hypoplastic AI. In patients with this condition, the presence of partially erupted teeth with soft tissue covering part of the crown, without a periodontal pocket, and with a radiographic image of partial coronal radiolucency should lead to suspicion of external coronary resorption.
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6
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Rossi S, Castiglia D, Pisaneschi E, Diociaiuti A, Stracuzzi A, Cesario C, Mariani R, Floriddia G, Zambruno G, Boldrini R, Abeni D, Novelli A, Alaggio R, El Hachem M. Immunofluorescence mapping, electron microscopy and genetics in the diagnosis and sub-classification of inherited epidermolysis bullosa: a single-centre retrospective comparative study of 87 cases with long-term follow-up. J Eur Acad Dermatol Venereol 2021; 35:1007-1016. [PMID: 33274474 DOI: 10.1111/jdv.17060] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Epidermolysis bullosa (EB) comprises a heterogeneous group of skin fragility disorders, classified in four major types based on skin cleavage level, i.e. EB simplex (EBS), junctional EB (JEB), dystrophic EB (DEB), Kindler EB, and in more than 30 subtypes defined by the combination of laboratory and clinical data, including disease course. OBJECTIVES Our aims were to address whether, in the age of genomics, electron microscopy (TEM) has still a role in diagnosing EB, and whether the genotype per se may be sufficient to sub-classify EB. METHODS A thoroughly characterized single-centre EB case series was retrospectively evaluated to compare the power of TEM with immunofluorescence mapping (IFM) in establishing the EB type, and the ability of TEM, IFM and genetics to predict selected EB subtypes, i.e. severe dominant EBS (DEBS), severe JEB, severe recessive DEB (RDEB) and DEB self-improving, using genetic and final diagnosis, respectively, as gold standard. RESULTS The series consisted of 87 patients, including 44 newborns, with a median follow-up of 54 months. Ninety-five mutations were identified in EB-associated genes, including 25 novel variants. Both IFM and TEM were diagnostic in about all cases of JEB (21/21 for both) and DEB (43/44 for IFM, 44/44 for TEM). TEM sensitivity was superior to IFM for EBS (19/20 vs. 16/19). As to EB subtyping, IFM performed better than genetics in identifying severe JEB cases due to laminin-332 defect (14/14 vs. 10/14) and severe RDEB (eight/nine vs. seven/nine). Genetics had no role in self-improving DEB diagnosis; it almost equalled TEM in predicting severe DEBS (eight/nine vs. nine/nine) and enabled to discriminate dominant from recessive non-severe DEB phenotypes and to identify special subtypes, e.g. DEBS with KLHL24 mutations. CONCLUSIONS Transmission electron microscopy remains relevant to the diagnosis of EBS. IFM and genetics are essential and complementary tools in the vast majority of EB cases.
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Affiliation(s)
- S Rossi
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - E Pisaneschi
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - A Diociaiuti
- Dermatology Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - A Stracuzzi
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - C Cesario
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Mariani
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - G Zambruno
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Boldrini
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | | | - A Novelli
- Laboratory of Medical Genetics, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - R Alaggio
- Pathology Unit, Department of Laboratories, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - M El Hachem
- Dermatology Department, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
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7
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Krämer S, Lucas J, Gamboa F, Peñarrocha Diago M, Peñarrocha Oltra D, Guzmán‐Letelier M, Paul S, Molina G, Sepúlveda L, Araya I, Soto R, Arriagada C, Lucky AW, Mellerio JE, Cornwall R, Alsayer F, Schilke R, Antal MA, Castrillón F, Paredes C, Serrano MC, Clark V. Clinical practice guidelines: Oral health care for children and adults living with epidermolysis bullosa. SPECIAL CARE IN DENTISTRY 2020; 40 Suppl 1:3-81. [PMID: 33202040 PMCID: PMC7756753 DOI: 10.1111/scd.12511] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Inherited epidermolysis bullosa (EB) is a genetic disorder characterized by skin fragility and unique oral features. AIMS To provide (a) a complete review of the oral manifestations in those living with each type of inherited EB, (b) the current best practices for managing oral health care of people living with EB, (c) the current best practices on dental implant-based oral rehabilitation for patients with recessive dystrophic EB (RDEB), and (d) the current best practice for managing local anesthesia, principles of sedation, and general anesthesia for children and adults with EB undergoing dental treatment. METHODS Systematic literature search, panel discussion including clinical experts and patient representatives from different centers around the world, external review, and guideline piloting. RESULTS This article has been divided into five chapters: (i) general information on EB for the oral health care professional, (ii) systematic literature review on the oral manifestations of EB, (iii) oral health care and dental treatment for children and adults living with EB-clinical practice guidelines, (iv) dental implants in patients with RDEB-clinical practice guidelines, and (v) sedation and anesthesia for adults and children with EB undergoing dental treatment-clinical practice guidelines. Each chapter provides recommendations on the management of the different clinical procedures within dental practice, highlighting the importance of patient-clinician partnership, impact on quality of life, and the importance of follow-up appointments. Guidance on the use on nonadhesive wound care products and emollients to reduce friction during patient care is provided. CONCLUSIONS Oral soft and hard tissue manifestations of inherited EB have unique patterns of involvement associated with each subtype of the condition. Understanding each subtype individually will help the professionals plan long-term treatment approaches.
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Affiliation(s)
- Susanne Krämer
- Facultad de OdontologíaUniversidad de ChileSantiagoChile
| | - James Lucas
- Dental DepartmentRoyal Children's HospitalMelbourneAustralia
| | | | | | | | - Marcelo Guzmán‐Letelier
- Hospital Base ValdiviaValdiviaChile
- Facultad de OdontologiaUniversidad San SebastiánValdiviaChile
| | | | - Gustavo Molina
- Universidad Nacional de CórdobaArgentina
- Universidad Católica de CórdobaArgentina
| | | | - Ignacio Araya
- Facultad de OdontologíaUniversidad de ChileSantiagoChile
- Hospital Santiago OrienteMaxillofacial Surgery UnitChile
| | - Rubén Soto
- Facultad de OdontologíaUniversidad de ChileSantiagoChile
| | | | - Anne W Lucky
- Cincinnati Children's Epidermolysis Bullosa CenterCincinnati Children's HospitalCincinnatiOhioUSA
- The University of Cincinnati College of MedicineCincinnatiOhioUSA
| | - Jemima E Mellerio
- St John's Institute of DermatologyGuy's and St Thomas’ NHS Foundation TrustLondonUK
| | - Roger Cornwall
- Cincinnati Children's Epidermolysis Bullosa CenterCincinnati Children's HospitalCincinnatiOhioUSA
| | - Fatimah Alsayer
- Royal National ENT and Eastman Dental HospitalsUniversity College London HospitalsLondonUK
| | - Reinhard Schilke
- Hannover Medical SchoolDepartment of Conservative DentistryPeriodontology and Preventive DentistryHannoverGermany
| | | | | | - Camila Paredes
- Facultad de OdontologíaUniversidad de ChileSantiagoChile
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8
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Green DR, Schulte F, Lee KH, Pugach MK, Hardt M, Bidlack FB. Mapping the Tooth Enamel Proteome and Amelogenin Phosphorylation Onto Mineralizing Porcine Tooth Crowns. Front Physiol 2019; 10:925. [PMID: 31417410 PMCID: PMC6682599 DOI: 10.3389/fphys.2019.00925] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/09/2019] [Indexed: 01/13/2023] Open
Abstract
Tooth enamel forms in an ephemeral protein matrix where changes in protein abundance, composition and posttranslational modifications are critical to achieve healthy enamel properties. Amelogenin (AMELX) with its splice variants is the most abundant enamel matrix protein, with only one known phosphorylation site at serine 16 shown in vitro to be critical for regulating mineralization. The phosphorylated form of AMELX stabilizes amorphous calcium phosphate, while crystalline hydroxyapatite forms in the presence of the unphosphorylated protein. While AMELX regulates mineral transitions over space and time, it is unknown whether and when un-phosphorylated amelogenin occurs during enamel mineralization. This study aims to reveal the spatiotemporal distribution of the cleavage products of the most abundant AMLEX splice variants including the full length P173, the shorter leucine-rich amelogenin protein (LRAP), and the exon 4-containing P190 in forming enamel, all within the context of the changing enamel matrix proteome during mineralization. We microsampled permanent pig molars, capturing known stages of enamel formation from both crown surface and inner enamel. Nano-LC-MS/MS proteomic analyses after tryptic digestion rendered more than 500 unique protein identifications in enamel, dentin, and bone. We mapped collagens, keratins, and proteolytic enzymes (CTSL, MMP2, MMP10) and determined distributions of P173, LRAP, and P190 products, the enamel proteins enamelin (ENAM) and ameloblastin (AMBN), and matrix-metalloprotease-20 (MMP20) and kallikrein-4 (KLK4). All enamel proteins and KLK4 were near-exclusive to enamel and in excellent agreement with published abundance levels. Phosphorylated P173 and LRAP products decreased in abundance from recently deposited matrix toward older enamel, mirrored by increasing abundances of testicular acid phosphatase (ACPT). Our results showed that hierarchical clustering analysis of secretory enamel links closely matching distributions of unphosphorylated P173 and LRAP products with ACPT and non-traditional amelogenesis proteins, many associated with enamel defects. We report higher protein diversity than previously published and Gene Ontology (GO)-defined protein functions related to the regulation of mineral formation in secretory enamel (e.g., casein α-S1, CSN1S1), immune response in erupted enamel (e.g., peptidoglycan recognition protein, PGRP), and phosphorylation. This study presents a novel approach to characterize and study functional relationships through spatiotemporal mapping of the ephemeral extracellular matrix proteome.
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Affiliation(s)
- Daniel R Green
- The Forsyth Institute, Cambridge, MA, United States.,Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States
| | | | - Kyu-Ha Lee
- The Forsyth Institute, Cambridge, MA, United States.,Department of Oral Health Policy and Epidemiology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Megan K Pugach
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Markus Hardt
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
| | - Felicitas B Bidlack
- The Forsyth Institute, Cambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental Medicine, Boston, MA, United States
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9
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Smith C, Poulter J, Brookes S, Murillo G, Silva S, Brown C, Patel A, Hussain H, Kirkham J, Inglehearn C, Mighell A. Phenotype and Variant Spectrum in the LAMB3 Form of Amelogenesis Imperfecta. J Dent Res 2019; 98:698-704. [PMID: 30905256 PMCID: PMC6535922 DOI: 10.1177/0022034519835205] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of inherited disorders characterized by abnormal formation of dental enamel, either in isolation or as part of a syndrome. Heterozygous variants in laminin subunit beta 3 ( LAMB3) cause AI with dominant inheritance in the absence of other cosegregating clinical features. In contrast, biallelic loss-of-function variants in LAMB3 cause recessive junctional epidermolysis bullosa, characterized by life-threatening skin fragility. We identified 2 families segregating autosomal dominant AI with variable degrees of a distinctive hypoplastic phenotype due to pathogenic variants in LAMB3. Whole exome sequencing revealed a nonsense variant (c.3340G>T, p.E1114*) within the final exon in family 1, while Sanger sequencing in family 2 revealed a variant (c.3383-1G>A) in the canonical splice acceptor site of the final exon. Analysis of cDNA from family 2 revealed retention of the final intron leading to a premature termination codon. Two unerupted third molar teeth from individual IV:5 in family 2 were subject to computerized tomography and scanning electron microscopy. LAMB3 molar teeth have a multitude of cusps versus matched controls. LAMB3 enamel was well mineralized but pitted. The architecture of the initially secreted enamel was abnormal, with cervical enamel appearing much less severely affected than coronal enamel. This study further defines the variations in phenotype-genotype correlation for AI due to variants in LAMB3, underlines the clustering of nonsense and frameshift variants causing AI in the absence of junctional epidermolysis bullosa, and highlights the shared AI phenotype arising from variants in genes coding for hemidesmosome proteins.
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Affiliation(s)
- C.E.L. Smith
- Division of Molecular Medicine, Leeds
Institute of Medical Research, University of Leeds, Leeds, UK
- Department of Oral Biology, School of
Dentistry, St James’s University Hospital, University of Leeds, Leeds, UK
| | - J.A. Poulter
- Division of Molecular Medicine, Leeds
Institute of Medical Research, University of Leeds, Leeds, UK
| | - S.J. Brookes
- Department of Oral Biology, School of
Dentistry, St James’s University Hospital, University of Leeds, Leeds, UK
| | - G. Murillo
- School of Dentistry, Universidad de
Costa Rica, Ciudad Universitaria Rodrigo Facio, San Pedro Montes De Oca, Costa
Rica
| | - S. Silva
- Cellular and Molecular Biology Centre,
Universidad de Costa Rica, Ciudad Universitaria Rodrigo Facio, San Pedro Montes de
Oca, Costa Rica
| | - C.J. Brown
- Birmingham Dental Hospital and School of
Dentistry, Edgbaston, Birmingham, UK
| | - A. Patel
- Birmingham Dental Hospital and School of
Dentistry, Edgbaston, Birmingham, UK
| | - H. Hussain
- School of Medicine, University of Leeds,
Leeds, UK
| | - J. Kirkham
- Department of Oral Biology, School of
Dentistry, St James’s University Hospital, University of Leeds, Leeds, UK
| | - C.F. Inglehearn
- Division of Molecular Medicine, Leeds
Institute of Medical Research, University of Leeds, Leeds, UK
| | - A.J. Mighell
- School of Dentistry, University of
Leeds, Leeds, UK
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10
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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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11
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Prasad MK, Laouina S, El Alloussi M, Dollfus H, Bloch-Zupan A. Amelogenesis Imperfecta: 1 Family, 2 Phenotypes, and 2 Mutated Genes. J Dent Res 2016; 95:1457-1463. [PMID: 27558265 DOI: 10.1177/0022034516663200] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a clinically and genetically heterogeneous group of diseases characterized by enamel defects. The authors have identified a large consanguineous Moroccan family segregating different clinical subtypes of hypoplastic and hypomineralized AI in different individuals within the family. Using targeted next-generation sequencing, the authors identified a novel heterozygous nonsense mutation in COL17A1 (c.1873C>T, p.R625*) segregating with hypoplastic AI and a novel homozygous 8-bp deletion in C4orf26 (c.39_46del, p.Cys14Glyfs*18) segregating with hypomineralized-hypoplastic AI in this family. This study highlights the phenotypic and genotypic heterogeneity of AI that can exist even within a single consanguineous family. Furthermore, the identification of novel mutations in COL17A1 and C4orf26 and their correlation with distinct AI phenotypes can contribute to a better understanding of the pathophysiology of AI and the contribution of these genes to amelogenesis.
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Affiliation(s)
- M K Prasad
- Laboratoire de Génétique Médicale, INSERM U1112, Institut de Génétique Médicale d'Alsace, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - S Laouina
- Department of Pediatric Dentistry, Faculty of Dental Medicine, Mohammed V University, Rabat, Morocco
| | - M El Alloussi
- Department of Pediatric Dentistry, Faculty of Dental Medicine, Mohammed V University, Rabat, Morocco
| | - H Dollfus
- Laboratoire de Génétique Médicale, INSERM U1112, Institut de Génétique Médicale d'Alsace, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
- Centre de Référence pour les Affections Rares en Génétique Ophtalmologique, Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - A Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
- Pôle de Médecine et Chirurgie Bucco-Dentaires, Centre de Référence des Manifestations Odontologiques des Maladies Rares, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- Institut de Génétique et de Biologie Moléculaire and Cellulaire, CNRS UMR7104, INSERM U964, Centre Européen de Recherche en Biologie et en Médecine, Université de Strasbourg, Illkirch, France
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12
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Gostyńska KB, Yan Yuen W, Pasmooij AMG, Stellingsma C, Pas HH, Lemmink H, Jonkman MF. Carriers with functional null mutations in LAMA3 have localized enamel abnormalities due to haploinsufficiency. Eur J Hum Genet 2016; 25:94-99. [PMID: 27827380 DOI: 10.1038/ejhg.2016.136] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Revised: 08/10/2016] [Accepted: 09/06/2016] [Indexed: 11/09/2022] Open
Abstract
The hereditary blistering disease junctional epidermolysis bullosa (JEB) is always accompanied by structural enamel abnormalities of primary and secondary dentition, characterized as amelogenesis imperfecta. Autosomal recessive mutations in LAMA3, LAMB3 and LAMC2 encoding the heterotrimer laminin 332 (LM-332) are among the genes causing JEB. While examining pedigrees of JEB patients with LAMA3 mutations, we observed that heterozygous carriers of functional null mutations displayed subtle enamel pitting in the absence of skin fragility or other JEB symptoms. Here, we report two new LAMA3 functional null mutations: nonsense c.2377C>T p.(Arg793Ter) and splice-site c.4684+1G>A mutation in heterozygous carriers exhibiting enamel pitting. Both parents had offspring affected with JEB and displayed subtle enamel pitting of secondary dentition without any sign of skin blistering. The reported enamel abnormality in LAMA3 mutation carriers could be attributed to a half dose effect of the laminin α3 chain (haploinsufficiency).
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Affiliation(s)
- Katarzyna B Gostyńska
- Departments of Dermatology, Center for Blistering Diseases, Groningen, The Netherlands.
| | - Wing Yan Yuen
- Departments of Dermatology, Center for Blistering Diseases, Groningen, The Netherlands
| | | | - Cornelius Stellingsma
- Oral and Maxillofacial Surgery and Maxillofacial Prosthetics Genetics, Groningen, The Netherlands
| | - Hendri H Pas
- Departments of Dermatology, Center for Blistering Diseases, Groningen, The Netherlands
| | - Henny Lemmink
- University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Marcel F Jonkman
- Departments of Dermatology, Center for Blistering Diseases, Groningen, The Netherlands
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13
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Yuen WY, Di Zenzo G, Jonkman MF, Pas HH. New versatile monoclonal antibodies against type XVII collagen endodomain for diagnosis and subtyping COL17A1-associated junctional epidermolysis bullosa. J Eur Acad Dermatol Venereol 2016; 30:1426-7. [PMID: 26334130 DOI: 10.1111/jdv.13270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- W Y Yuen
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - G Di Zenzo
- Molecular and Cell Biology Laboratory, Istituto Dermopatico dell'Immacolata, Istituto di Ricovero e Cura a Carattere Scientifico (IDI-IRCCS), Rome, Italy
| | - M F Jonkman
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - H H Pas
- Department of Dermatology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
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14
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Prasad MK, Geoffroy V, Vicaire S, Jost B, Dumas M, Le Gras S, Switala M, Gasse B, Laugel-Haushalter V, Paschaki M, Leheup B, Droz D, Dalstein A, Loing A, Grollemund B, Muller-Bolla M, Lopez-Cazaux S, Minoux M, Jung S, Obry F, Vogt V, Davideau JL, Davit-Beal T, Kaiser AS, Moog U, Richard B, Morrier JJ, Duprez JP, Odent S, Bailleul-Forestier I, Rousset MM, Merametdijan L, Toutain A, Joseph C, Giuliano F, Dahlet JC, Courval A, El Alloussi M, Laouina S, Soskin S, Guffon N, Dieux A, Doray B, Feierabend S, Ginglinger E, Fournier B, de la Dure Molla M, Alembik Y, Tardieu C, Clauss F, Berdal A, Stoetzel C, Manière MC, Dollfus H, Bloch-Zupan A. A targeted next-generation sequencing assay for the molecular diagnosis of genetic disorders with orodental involvement. J Med Genet 2016; 53:98-110. [PMID: 26502894 PMCID: PMC4752661 DOI: 10.1136/jmedgenet-2015-103302] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2015] [Revised: 09/08/2015] [Accepted: 09/24/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. METHODS We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. RESULTS We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. CONCLUSIONS We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. TRIAL REGISTRATION NUMBERS NCT01746121 and NCT02397824.
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Affiliation(s)
- Megana K Prasad
- Laboratoire de Génétique Médicale, INSERMU1112, Institut de génétique médicale d'Alsace, FMTS, Université de Strasbourg, Strasbourg, France
| | - Véronique Geoffroy
- Laboratoire de Génétique Médicale, INSERMU1112, Institut de génétique médicale d'Alsace, FMTS, Université de Strasbourg, Strasbourg, France
| | - Serge Vicaire
- Plateforme de Biopuces et Séquençage, Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch, France
| | - Bernard Jost
- Plateforme de Biopuces et Séquençage, Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch, France
| | - Michael Dumas
- Plateforme de Biopuces et Séquençage, Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch, France
| | - Stéphanie Le Gras
- Plateforme de Biopuces et Séquençage, Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964, Université de Strasbourg, Illkirch, France
| | - Marzena Switala
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Barbara Gasse
- Evolution et Développement du Squelette-EDS, UMR7138-SAE, Université Pierre et Marie Curie, Paris, France
| | - Virginie Laugel-Haushalter
- Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964 Université de Strasbourg, Illkirch, France
| | - Marie Paschaki
- Laboratoire de Génétique Médicale, INSERMU1112, Institut de génétique médicale d'Alsace, FMTS, Université de Strasbourg, Strasbourg, France
- Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964 Université de Strasbourg, Illkirch, France
| | - Bruno Leheup
- Faculté de Médecine, CHU de Nancy, Université de Lorraine, Vandoeuvre-Les-Nancy, France
| | | | | | - Adeline Loing
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
| | - Bruno Grollemund
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Michèle Muller-Bolla
- Départment d'Odontologie Pédiatrique, UFR d'Odontologie, Université de Nice Sophia-Antipolis, CHU de Nice, Nice, France
- URB2i—EA 4462, Paris Descartes, Paris, France
| | - Séréna Lopez-Cazaux
- Faculté de Chirurgie Dentaire, Département d'Odontologie Pédiatrique, CHU Hotel Dieu, Service d'odontologie conservatrice et pédiatrique, Nantes, France
| | - Maryline Minoux
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Sophie Jung
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Frédéric Obry
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Vincent Vogt
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Jean-Luc Davideau
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Tiphaine Davit-Beal
- Evolution et Développement du Squelette-EDS, UMR7138-SAE, Université Pierre et Marie Curie, Paris, France
- Faculté de Chirurgie Dentaire, Département d'Odontologie Pédiatrique, Université Paris Descartes, Montrouge, France
| | | | - Ute Moog
- Institute of Human Genetics, Heidelberg University, Heidelberg, Germany
| | - Béatrice Richard
- Service de Consultations et Traitements Dentaires, Hospices Civils de Lyon, Faculté d'Odontologie, Université Claude Bernard Lyon1, Lyon, France
| | - Jean-Jacques Morrier
- Service de Consultations et Traitements Dentaires, Hospices Civils de Lyon, Faculté d'Odontologie, Université Claude Bernard Lyon1, Lyon, France
| | - Jean-Pierre Duprez
- Service de Consultations et Traitements Dentaires, Hospices Civils de Lyon, Faculté d'Odontologie, Université Claude Bernard Lyon1, Lyon, France
| | - Sylvie Odent
- Service de Génétique Clinique, CHU de Rennes, Rennes, France
| | - Isabelle Bailleul-Forestier
- Faculté de Chirurgie Dentaire, CHU de Toulouse, Odontologie Pédiatrique, Université Paul Sabatier, Toulouse, France
| | - Monique Marie Rousset
- Unité Fonctionnelle d'Odontologie pédiatrique, Service d'odontologie, CHRU de Lille, Lille, France
| | - Laure Merametdijan
- Faculté de Chirurgie Dentaire, Service d'Odontologie Conservatrice et Endodontie, CHU Nantes, Université de Nantes, France
| | | | - Clara Joseph
- Départment d'Odontologie Pédiatrique, Université de Nice Sophia-Antipolis, CHU Nice, Nice, France
| | | | - Jean-Christophe Dahlet
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
| | - Aymeric Courval
- Pôle de Médecine et de Chirurgie Bucco-dentaire, Hôpital Civil, HUS, Strasbourg, France
| | - Mustapha El Alloussi
- Faculty of Dental Medicine, Department of Pediatric Dentistry, University Mohammed V Rabat, Morocco
| | - Samir Laouina
- Faculty of Dental Medicine, Department of Pediatric Dentistry, University Mohammed V Rabat, Morocco
| | - Sylvie Soskin
- Pédiatrie 1, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | | | - Anne Dieux
- Service de génétique clinique Guy Fontaine, Centre Hospitalier Régionale Universitaire (CHRU) de Lille, Lille, France
| | - Bérénice Doray
- Service de Génétique Médicale, CHU de Strasbourg, Strasbourg, France
| | - Stephanie Feierabend
- Klinik für Zahnerhaltungskunde und Parodontologie, Universitats Klinikum, Freiburg, Germany
| | | | - Benjamin Fournier
- Laboratoire de Physiopathologie Orale Moléculaire INSERM UMR S1138, Centre de Recherche des Cordeliers, Universités Paris-Diderot et Paris-Descartes, Paris, France
- Centre de Référence des Malformations Rares de la Face et de la Cavité Buccale MAFACE, Hôpital Rothschild, Pôle d'Odontologie, Paris, France
| | - Muriel de la Dure Molla
- Laboratoire de Physiopathologie Orale Moléculaire INSERM UMR S1138, Centre de Recherche des Cordeliers, Universités Paris-Diderot et Paris-Descartes, Paris, France
- Centre de Référence des Malformations Rares de la Face et de la Cavité Buccale MAFACE, Hôpital Rothschild, Pôle d'Odontologie, Paris, France
| | - Yves Alembik
- Service de Génétique Médicale, CHU de Strasbourg, Strasbourg, France
| | - Corinne Tardieu
- Aix-Marseille Université, UMR 7268 ADES/EFS/CNRS, APHM, Hôpital Timone, Service Odontologie, Marseille, France
| | - François Clauss
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Ariane Berdal
- Laboratoire de Physiopathologie Orale Moléculaire INSERM UMR S1138, Centre de Recherche des Cordeliers, Universités Paris-Diderot et Paris-Descartes, Paris, France
- Centre de Référence des Malformations Rares de la Face et de la Cavité Buccale MAFACE, Hôpital Rothschild, Pôle d'Odontologie, Paris, France
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, INSERMU1112, Institut de génétique médicale d'Alsace, FMTS, Université de Strasbourg, Strasbourg, France
| | - Marie Cécile Manière
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, INSERMU1112, Institut de génétique médicale d'Alsace, FMTS, Université de Strasbourg, Strasbourg, France
- Service de Génétique Médicale, Centre de Référence pour les Affections Rares en Génétique Ophtalmologique, HUS, Strasbourg, France
| | - Agnès Bloch-Zupan
- Centre de Référence des Manifestations Odontologiques des Maladies Rares, Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
- Institut de Génétique et de Biologie Moléculaire and Cellulaire-Centre Européen de Recherche en Biologie et en Médecine, CNRS UMR7104, INSERM U964 Université de Strasbourg, Illkirch, France
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15
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Nishimura M, Nishie W, Shirafuji Y, Shinkuma S, Natsuga K, Nakamura H, Sawamura D, Iwatsuki K, Shimizu H. Extracellular cleavage of collagen XVII is essential for correct cutaneous basement membrane formation. Hum Mol Genet 2016; 25:328-39. [PMID: 26604146 DOI: 10.1093/hmg/ddv478] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/16/2015] [Indexed: 02/04/2023] Open
Abstract
In skin, basal keratinocytes in the epidermis are tightly attached to the underlying dermis by the basement membrane (BM). The correct expression of hemidesmosomal and extracellular matrix (ECM) proteins is essential for BM formation, and the null-expression of one molecule may induce blistering diseases associated with immature BM formation in humans. However, little is known about the significance of post-translational processing of hemidesmosomal or ECM proteins in BM formation. Here we show that the C-terminal cleavage of hemidesmosomal transmembrane collagen XVII (COL17) is essential for correct BM formation. The homozygous p.R1303Q mutation in COL17 induces BM duplication and blistering in humans. Although laminin 332, a major ECM protein, interacts with COL17 around p.R1303, the mutation leaves the binding of both molecules unchanged. Instead, the mutation hampers the physiological C-terminal cleavage of COL17 in the ECM. Consequently, non-cleaved COL17 ectodomain remnants induce the aberrant deposition of laminin 332 in the ECM, which is thought to be the major pathogenesis of the BM duplication that results from this mutation. As an example of impaired cleavage of COL17, this study shows that regulated processing of hemidesmosomal proteins is essential for correct BM organization in skin.
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Affiliation(s)
- Machiko Nishimura
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Wataru Nishie
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan,
| | - Yoshinori Shirafuji
- Department of Dermatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-Cho, Kita-Ku, Okayama 700-8558, Japan and
| | - Satoru Shinkuma
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Ken Natsuga
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Hideki Nakamura
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan
| | - Daisuke Sawamura
- Department of Dermatology, Hirosaki University Graduate School of Medicine, Zaifu-Cho 5, Hirosaki 036-8562, Japan
| | - Keiji Iwatsuki
- Department of Dermatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-Cho, Kita-Ku, Okayama 700-8558, Japan and
| | - Hiroshi Shimizu
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan,
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16
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Turcan I, Jonkman MF. Blistering disease: insight from the hemidesmosome and other components of the dermal-epidermal junction. Cell Tissue Res 2014; 360:545-69. [PMID: 25502077 DOI: 10.1007/s00441-014-2021-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 09/25/2014] [Indexed: 02/07/2023]
Abstract
The hemidesmosome is a specialized transmembrane complex that mediates the binding of epithelial cells to the underlying basement membrane. In the skin, this multiprotein structure can be regarded as the chief adhesion unit at the site of the dermal-epidermal junction. Focal adhesions are additional specialized attachment structures located between hemidesmosomes. The integrity of the skin relies on well-assembled and functional hemidesmosomes and focal adhesions (also known as integrin adhesomes). However, if these adhesion structures are impaired, e.g., as a result of circulating autoantibodies or inherited genetic mutations, the mechanical strength of the skin is compromised, leading to blistering and/or tissue inflammation. A particular clinical presentation emerges subject to the molecule that is targeted. None of these junctional complexes are simply compounds of adhesion molecules; they also play a significant role in signalling pathways involved in the differentiation and migration of epithelial cells such as during wound healing and in tumour invasion. We summarize current knowledge about hereditary and acquired blistering diseases emerging from pathologies of the hemidesmosome and its neighbouring proteins as components of the dermal-epidermal junction.
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Affiliation(s)
- Iana Turcan
- Centre for Blistering Diseases, Department of Dermatology, University Medical Centre Groningen, University of Groningen, P.O. Box 30.001, 9700 RB, Groningen, The Netherlands,
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Lee KE, Ko J, Le CGT, Shin TJ, Hyun HK, Lee SH, Kim JW. Novel LAMB3 mutations cause non-syndromic amelogenesis imperfecta with variable expressivity. Clin Genet 2014; 87:90-2. [PMID: 24494736 PMCID: PMC4302247 DOI: 10.1111/cge.12340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2013] [Revised: 12/30/2013] [Accepted: 01/03/2014] [Indexed: 11/28/2022]
Affiliation(s)
- K-E Lee
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea
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Poulter JA, El-Sayed W, Shore RC, Kirkham J, Inglehearn CF, Mighell AJ. Whole-exome sequencing, without prior linkage, identifies a mutation in LAMB3 as a cause of dominant hypoplastic amelogenesis imperfecta. Eur J Hum Genet 2014; 22:132-5. [PMID: 23632796 PMCID: PMC3865405 DOI: 10.1038/ejhg.2013.76] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 03/24/2013] [Indexed: 01/13/2023] Open
Abstract
The conventional approach to identifying the defective gene in a family with an inherited disease is to find the disease locus through family studies. However, the rapid development and decreasing cost of next generation sequencing facilitates a more direct approach. Here, we report the identification of a frameshift mutation in LAMB3 as a cause of dominant hypoplastic amelogenesis imperfecta (AI). Whole-exome sequencing of three affected family members and subsequent filtering of shared variants, without prior genetic linkage, sufficed to identify the pathogenic variant. Simultaneous analysis of multiple family members confirms segregation, enhancing the power to filter the genetic variation found and leading to rapid identification of the pathogenic variant. LAMB3 encodes a subunit of Laminin-5, one of a family of basement membrane proteins with essential functions in cell growth, movement and adhesion. Homozygous LAMB3 mutations cause junctional epidermolysis bullosa (JEB) and enamel defects are seen in JEB cases. However, to our knowledge, this is the first report of dominant AI due to a LAMB3 mutation in the absence of JEB.
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Affiliation(s)
- James A Poulter
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK
| | - Walid El-Sayed
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK
- Department of Oral Biology, Dental School, Suez Canal University, Ismailia, Egypt
- Department of Oral Medicine, Leeds Dental Institute, University of Leeds, Leeds, UK
| | - Roger C Shore
- Department of Oral Biology, Leeds Dental Institute, University of Leeds, Leeds, UK
| | - Jennifer Kirkham
- Department of Oral Biology, Leeds Dental Institute, University of Leeds, Leeds, UK
| | - Chris F Inglehearn
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK
| | - Alan J Mighell
- Section of Ophthalmology and Neuroscience, Leeds Institute of Molecular Medicine, University of Leeds, Leeds, UK
- Department of Oral Medicine, Leeds Dental Institute, University of Leeds, Leeds, UK
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Wang SK, Choi M, Richardson AS, Reid BM, Lin BP, Wang SJ, Kim JW, Simmer JP, Hu JCC. ITGB6 loss-of-function mutations cause autosomal recessive amelogenesis imperfecta. Hum Mol Genet 2013; 23:2157-63. [PMID: 24305999 DOI: 10.1093/hmg/ddt611] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Integrins are cell-surface adhesion receptors that bind to extracellular matrices (ECM) and mediate cell-ECM interactions. Some integrins are known to play critical roles in dental enamel formation. We recruited two Hispanic families with generalized hypoplastic amelogenesis imperfecta (AI). Analysis of whole-exome sequences identified three integrin beta 6 (ITGB6) mutations responsible for their enamel malformations. The female proband of Family 1 was a compound heterozygote with an ITGB6 transition mutation in Exon 4 (g.4545G > A c.427G > A p.Ala143Thr) and an ITGB6 transversion mutation in Exon 6 (g.27415T > A c.825T > A p.His275Gln). The male proband of Family 2 was homozygous for an ITGB6 transition mutation in Exon 11 (g.73664C > T c.1846C > T p.Arg616*) and hemizygous for a transition mutation in Exon 6 of Nance-Horan Syndrome (NHS Xp22.13; g.355444T > C c.1697T > C p.Met566Thr). These are the first disease-causing ITGB6 mutations to be reported. Immunohistochemistry of mouse mandibular incisors localized ITGB6 to the distal membrane of differentiating ameloblasts and pre-ameloblasts, and then ITGB6 appeared to be internalized by secretory stage ameloblasts. ITGB6 expression was strongest in the maturation stage and its localization was associated with ameloblast modulation. Our findings demonstrate that early and late amelogenesis depend upon cell-matrix interactions. Our approach (from knockout mouse phenotype to human disease) demonstrates the power of mouse reverse genetics in mutational analysis of human genetic disorders and attests to the need for a careful dental phenotyping in large-scale knockout mouse projects.
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Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1210 Eisenhower Place, Ann Arbor, MI 48108, USA
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Kim J, Seymen F, Lee K, Ko J, Yildirim M, Tuna E, Gencay K, Shin T, Kyun H, Simmer J, Hu JC. LAMB3 mutations causing autosomal-dominant amelogenesis imperfecta. J Dent Res 2013; 92:899-904. [PMID: 23958762 PMCID: PMC3775375 DOI: 10.1177/0022034513502054] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/12/2013] [Accepted: 07/26/2013] [Indexed: 01/13/2023] Open
Abstract
Amelogenesis imperfecta (AI) can be either isolated or part of a larger syndrome. Junctional epidermolysis bullosa (JEB) is a collection of autosomal-recessive disorders featuring AI associated with skin fragility and other symptoms. JEB is a recessive syndrome usually caused by mutations in both alleles of COL17A1, LAMA3, LAMB3, or LAMC2. In rare cases, heterozygous carriers in JEB kindreds display enamel malformations in the absence of skin fragility (isolated AI). We recruited two kindreds with autosomal-dominant amelogenesis imperfecta (ADAI) characterized by generalized severe enamel hypoplasia with deep linear grooves and pits. Whole-exome sequencing of both probands identified novel heterozygous mutations in the last exon of LAMB3 that likely truncated the protein. The mutations perfectly segregated with the enamel defects in both families. In Family 1, an 8-bp deletion (c.3446_3453del GACTGGAG) shifted the reading frame (p.Gly 1149Glufs*8). In Family 2, a single nucleotide substitution (c.C3431A) generated an in-frame translation termination codon (p.Ser1144*). We conclude that enamel formation is particularly sensitive to defects in hemidesmosome/basement-membrane complexes and that syndromic and non-syndromic forms of AI can be etiologically related.
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Affiliation(s)
- J.W. Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
- Department of Molecular Genetics & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - F. Seymen
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - K.E. Lee
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - J. Ko
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - M. Yildirim
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - E.B. Tuna
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - K. Gencay
- Department of Pedodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
| | - T.J. Shin
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - H.K. Kyun
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - J.P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Laboratory, 1210 Eisenhower Place, Ann Arbor, MI 48108, USA
| | - J.C.-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Laboratory, 1210 Eisenhower Place, Ann Arbor, MI 48108, USA
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Umemoto H, Akiyama M, Domon T, Nomura T, Shinkuma S, Ito K, Asaka T, Sawamura D, Uitto J, Uo M, Kitagawa Y, Shimizu H. Type VII collagen deficiency causes defective tooth enamel formation due to poor differentiation of ameloblasts. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1659-71. [PMID: 22940071 DOI: 10.1016/j.ajpath.2012.07.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 07/05/2012] [Accepted: 07/18/2012] [Indexed: 01/13/2023]
Abstract
Recessive dystrophic epidermolysis bullosa (RDEB) is caused by mutations in the gene encoding type VII collagen (COL7), a major component of anchoring fibrils in the epidermal basement membrane zone. Patients with RDEB present a low oral hygiene index and prevalent tooth abnormalities with caries. We examined the tooth enamel structure of an RDEB patient by scanning electron microscopy. It showed irregular enamel prisms, indicating structural enamel defects. To elucidate the pathomechanisms of enamel defects due to COL7 deficiency, we investigated tooth formation in Col7a1(-/-) and COL7-rescued humanized mice that we have established. The enamel from Col7a1(-/-) mice had normal surface structure. The enamel calcification and chemical composition of Col7a1(-/-) mice were similar to those of the wild type. However, transverse sections of teeth from the Col7a1(-/-) mice showed irregular enamel prisms, which were also observed in the RDEB patient. Furthermore, the Col7a1(-/-) mice teeth had poorly differentiated ameloblasts, lacking normal enamel protein-secreting Tomes' processes, and showed reduced mRNA expression of amelogenin and other enamel-related molecules. These enamel abnormalities were corrected in the COL7-rescued humanized mice expressing a human COL7A1 transgene. These findings suggest that COL7 regulates ameloblast differentiation and is essential for the formation of Tomes' processes. Collectively, COL7 deficiency is thought to disrupt epithelial-mesenchymal interactions, leading to defective ameloblast differentiation and enamel malformation in RDEB patients.
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Affiliation(s)
- Hiroko Umemoto
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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Chan HC, Estrella NMRP, Milkovich RN, Kim JW, Simmer JP, Hu JCC. Target gene analyses of 39 amelogenesis imperfecta kindreds. Eur J Oral Sci 2011; 119 Suppl 1:311-23. [PMID: 22243262 PMCID: PMC3292789 DOI: 10.1111/j.1600-0722.2011.00857.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Previously, mutational analyses identified six disease-causing mutations in 24 amelogenesis imperfecta (AI) kindreds. We have since expanded the number of AI kindreds to 39, and performed mutation analyses covering the coding exons and adjoining intron sequences for the six proven AI candidate genes [amelogenin (AMELX), enamelin (ENAM), family with sequence similarity 83, member H (FAM83H), WD repeat containing domain 72 (WDR72), enamelysin (MMP20), and kallikrein-related peptidase 4 (KLK4)] and for ameloblastin (AMBN) (a suspected candidate gene). All four of the X-linked AI families (100%) had disease-causing mutations in AMELX, suggesting that AMELX is the only gene involved in the aetiology of X-linked AI. Eighteen families showed an autosomal-dominant pattern of inheritance. Disease-causing mutations were identified in 12 (67%): eight in FAM83H, and four in ENAM. No FAM83H coding-region or splice-junction mutations were identified in three probands with autosomal-dominant hypocalcification AI (ADHCAI), suggesting that a second gene may contribute to the aetiology of ADHCAI. Six families showed an autosomal-recessive pattern of inheritance, and disease-causing mutations were identified in three (50%): two in MMP20, and one in WDR72. No disease-causing mutations were found in 11 families with only one affected member. We conclude that mutation analyses of the current candidate genes for AI have about a 50% chance of identifying the disease-causing mutation in a given kindred.
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Affiliation(s)
- Hui-Chen Chan
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Ninna M. R. P. Estrella
- Department of Orthodontics and Pediatric Dentistry, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Rachel N. Milkovich
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, MI, USA
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Abstract
This article describes the clinical services for EB in Australia and New Zealand. The history and epidemiology of EB in Australia is described. Current treatment and research achievements are described.
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Abstract
The craniofacial and oral manifestations of the different epidermolysis bullosa (EB) types vary markedly in character and severity depending largely on the EB type. The tissues affected and the phenotypes displayed are closely related to the specific abnormal or absent proteins resulting from the causative genetic mutations for these disorders. In this article, the major oral manifestations are reviewed for different EB subtypes and are related to the causative genetic mutations and gene expression.
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Abstract
Collagen XVII has been identified as having a role in inherited junctional epidermolysis bullosa non-Herlitz (JEB-other, MIM #226650). The role of collagen XVII in both autoimmune and genetic blistering disorders demonstrates its relevance to dermal-epidermal adhesion. Collagen XVII is a major structural component of the hemidesmosome (HD), a highly specialized multiprotein complex that mediates the anchorage of basal epithelial cells to the underlying basement membrane in stratified, pseudostratified, and transitional epithelia. This article examines the genetic and pathological features of collagen XVII.
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Affiliation(s)
- Cristina Has
- Department of Dermatology, University Medical Center Freiburg, Hauptstr. 7, 79104 Freiburg, Germany.
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Abstract
Laryngo-onycho-cutaneous (LOC) syndrome was reclassified as a subtype of junctional epidermolysis bullosa (JEB) based on clinical features similar to JEB and its association, in the majority of patients from the Punjab, with a unique mutation affecting the N terminus of the alpha3 chain of LM332. Although LOC syndrome is now a subtype of JEB(JEB-LOC) JEB-LOC has a distinct clinicopathologic appearance and molecular fingerprint. The intricacies of the JEB-LOC subtype are discussed in this article with regard to disease presentation, pathogenesis, management, and prognosis.
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Affiliation(s)
- Heather Irina Cohn
- Department of Dermatology and Cutaneous Biology, Jefferson Medical College, Thomas Jefferson University, Bluemle Life Sciences Building, 233 South 10th Street, Suite 450, Philadelphia, PA 19107, USA
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Almaani N, Liu L, Dopping-Hepenstal PJC, Lovell PA, Lai-Cheong JE, Graham RM, Mellerio JE, McGrath JA. Autosomal dominant junctional epidermolysis bullosa. Br J Dermatol 2009; 160:1094-7. [PMID: 19120338 DOI: 10.1111/j.1365-2133.2008.08977.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND Epidermolysis bullosa (EB) encompasses a heterogeneous group of inherited skin disorders associated with trauma-induced blistering. The junctional forms of EB (JEB), Herlitz JEB, non-Herlitz JEB and JEB associated with pyloric atresia have all been attributed to autosomal recessive inheritance. We describe a 7-year-old girl with defective dental enamel, trauma-induced blistering and subsequent scarring. Her mother, a carrier of the mutation p.G627V in the collagen XVII gene (COL17A1) had evidence of hypoplastic dental enamel without skin blistering. Her grandmother had non-Herlitz JEB as a result of a compound heterozygous mutation in COL17A1 (p.G627V and c.3514ins25). OBJECTIVES To explore the molecular, ultrastructural and immunofluorescence findings of the first case of dominant JEB. METHODS Mutational analysis of COL17A1 was performed on the proband's genomic DNA. In addition, transmission electron microscopy and immunofluorescence microscopy were performed on a nonlesional skin biopsy from the proband and an unrelated healthy control. RESULTS Direct sequencing revealed a heterozygous glycine substitution mutation, p.G627V, in COL17A1. No discernible morphological abnormalities were found on transmission electron microscopy; however, immunofluorescence microscopy revealed findings of an altered distribution pattern for type XVII collagen epitopes close to the dermal-epidermal junction. CONCLUSION This report describes the first case of dominant JEB. Although some heterozygous mutations in COL17A1 are known to cause dental abnormalities none were associated with skin fragility. The dominant-negative interference between the proband's mutated type XVII collagen and the wild-type allele appears to render the skin prone to trauma-induced blister formation. Alternatively, other undisclosed modifying genetic or epigenetic factors might explain why the patient gets blistering whereas her mother, who has the same COL17A1 mutation, has no skin fragility.
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Affiliation(s)
- N Almaani
- Genetic Skin Disease Group, St John's Institute of Dermatology, King's College London, Guy's Campus, London, UK
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Asaka T, Akiyama M, Domon T, Nishie W, Natsuga K, Fujita Y, Abe R, Kitagawa Y, Shimizu H. Type XVII collagen is a key player in tooth enamel formation. THE AMERICAN JOURNAL OF PATHOLOGY 2009; 174:91-100. [PMID: 19036806 PMCID: PMC2631322 DOI: 10.2353/ajpath.2009.080573] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/30/2008] [Indexed: 01/13/2023]
Abstract
Inherited tooth enamel hypoplasia occurs due to mutations in genes that encode major enamel components. Enamel hypoplasia also has been reported in junctional epidermolysis bullosa, caused by mutations in the genes that encode type XVII collagen (COL17), a component of the epithelial-mesenchymal junction. To elucidate the pathological mechanisms of the enamel hypoplasia that arise from the deficiency of epithelial-mesenchymal junction molecules, such as COL17, we investigated tooth formation in our recently established Col17(-/-) and Col17 rescued mice. Compared with wild-type mice, the incisors of the Col17(-/-) mice exhibited reduced yellow pigmentation, diminished iron deposition, delayed calcification, and markedly irregular enamel prisms, indicating the presence of enamel hypoplasia. The molars of the Col17(-/-) mice demonstrated advanced occlusal wear. These abnormalities were corrected in the Col17 rescued humanized mice. Thus, the Col17(-/-) mice clearly reproduced the enamel hypoplasia in human patients with junctional epidermolysis bullosa. We were able to investigate tooth formation in the Col17(-/-) mice because the Col17(-/-) genotype is not lethal. Col17(-/-) mouse incisors had poorly differentiated ameloblasts that lacked enamel protein-secreting Tomes' processes and reduced mRNA expression of amelogenin, ameloblastin, and of other enamel genes. These findings indicated that COL17 regulates ameloblast differentiation and is essential for normal formation of Tomes' processes. In conclusion, COL17 deficiency disrupts the epithelial-mesenchymal interactions, leading to both defective ameloblast differentiation and enamel malformation.
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Affiliation(s)
- Takuya Asaka
- Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan
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