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Xie Y, Qiu X, Gong J, Yuan Y, Xie D, Li S. Clinical application of whole exome sequencing technology in small-for-gestational-age children. Am J Transl Res 2023; 15:6813-6822. [PMID: 38186994 PMCID: PMC10767522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/25/2023] [Indexed: 01/09/2024]
Abstract
AIM To apply whole exome sequencing (WES) for molecular diagnosis of small-for-gestational-age (SGA) children. METHODS We retrospectively analyzed the data of 60 SGA children in our hospital, and performed developmental assessment, laboratory tests, imaging tests, and whole exome sequencing (WES), which were combined with clinical phenotypes to clarify the pathogenicity of the variant genes in the children. RESULTS Sixty SGA children were tested, and pathogenic SGA was detected at relatively high frequencies on chromosomes 7, 8, and 22. Of these, karyotype analysis clearly suggested developmental disorders in 4 patients. Also, a case of Wiedemann-Steiner syndrome due to a de novo nonsense variant in the KMT2A gene was detected. CONCLUSIONS The use of WES testing technology to increase the diagnosis rate of children with special SGA is conducive to the correct diagnosis and treatment of such children.
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Affiliation(s)
- Yunyun Xie
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
| | - Xiaolu Qiu
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
| | - Jun Gong
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
| | - Yufeng Yuan
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
| | - Dan Xie
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
| | - Shouming Li
- Department of Children Health, Jiangxi Provincial Children's Hospital Nanchang 330006, Jiangxi, China
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2
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Bloch-Zupan A, Rey T, Jimenez-Armijo A, Kawczynski M, Kharouf N, Dure-Molla MDL, Noirrit E, Hernandez M, Joseph-Beaudin C, Lopez S, Tardieu C, Thivichon-Prince B, Dostalova T, Macek M, Alloussi ME, Qebibo L, Morkmued S, Pungchanchaikul P, Orellana BU, Manière MC, Gérard B, Bugueno IM, Laugel-Haushalter V. Amelogenesis imperfecta: Next-generation sequencing sheds light on Witkop's classification. Front Physiol 2023; 14:1130175. [PMID: 37228816 PMCID: PMC10205041 DOI: 10.3389/fphys.2023.1130175] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/06/2023] [Indexed: 05/27/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of genetic rare diseases disrupting enamel development (Smith et al., Front Physiol, 2017a, 8, 333). The clinical enamel phenotypes can be described as hypoplastic, hypomineralized or hypomature and serve as a basis, together with the mode of inheritance, to Witkop's classification (Witkop, J Oral Pathol, 1988, 17, 547-553). AI can be described in isolation or associated with others symptoms in syndromes. Its occurrence was estimated to range from 1/700 to 1/14,000. More than 70 genes have currently been identified as causative. Objectives: We analyzed using next-generation sequencing (NGS) a heterogeneous cohort of AI patients in order to determine the molecular etiology of AI and to improve diagnosis and disease management. Methods: Individuals presenting with so called "isolated" or syndromic AI were enrolled and examined at the Reference Centre for Rare Oral and Dental Diseases (O-Rares) using D4/phenodent protocol (www.phenodent.org). Families gave written informed consents for both phenotyping and molecular analysis and diagnosis using a dedicated NGS panel named GenoDENT. This panel explores currently simultaneously 567 genes. The study is registered under NCT01746121 and NCT02397824 (https://clinicaltrials.gov/). Results: GenoDENT obtained a 60% diagnostic rate. We reported genetics results for 221 persons divided between 115 AI index cases and their 106 associated relatives from a total of 111 families. From this index cohort, 73% were diagnosed with non-syndromic amelogenesis imperfecta and 27% with syndromic amelogenesis imperfecta. Each individual was classified according to the AI phenotype. Type I hypoplastic AI represented 61 individuals (53%), Type II hypomature AI affected 31 individuals (27%), Type III hypomineralized AI was diagnosed in 18 individuals (16%) and Type IV hypoplastic-hypomature AI with taurodontism concerned 5 individuals (4%). We validated the genetic diagnosis, with class 4 (likely pathogenic) or class 5 (pathogenic) variants, for 81% of the cohort, and identified candidate variants (variant of uncertain significance or VUS) for 19% of index cases. Among the 151 sequenced variants, 47 are newly reported and classified as class 4 or 5. The most frequently discovered genotypes were associated with MMP20 and FAM83H for isolated AI. FAM20A and LTBP3 genes were the most frequent genes identified for syndromic AI. Patients negative to the panel were resolved with exome sequencing elucidating for example the gene involved ie ACP4 or digenic inheritance. Conclusion: NGS GenoDENT panel is a validated and cost-efficient technique offering new perspectives to understand underlying molecular mechanisms of AI. Discovering variants in genes involved in syndromic AI (CNNM4, WDR72, FAM20A … ) transformed patient overall care. Unravelling the genetic basis of AI sheds light on Witkop's AI classification.
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Affiliation(s)
- Agnes Bloch-Zupan
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut d’études avancées (USIAS), Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Eastman Dental Institute, University College London, London, United Kingdom
| | - Tristan Rey
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Alexandra Jimenez-Armijo
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Marzena Kawczynski
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Naji Kharouf
- Université de Strasbourg, Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Strasbourg, France
| | | | - Muriel de La Dure-Molla
- Rothschild Hospital, Public Assistance-Paris Hospitals (AP-HP), Reference Center for Rare Oral and Den-tal Diseases (O-Rares), Paris, France
| | - Emmanuelle Noirrit
- Centre Hospitalier Universitaire (CHU) Rangueil, Toulouse, Competence Center for Rare Oral and Den-tal Diseases, Toulouse, France
| | - Magali Hernandez
- Centre Hospitalier Régional Universitaire de Nancy, Université de Lorraine, Competence Center for Rare Oral and Dental Diseases, Nancy, France
| | - Clara Joseph-Beaudin
- Centre Hospitalier Universitaire de Nice, Competence Center for Rare Oral and Dental Diseases, Nice, France
| | - Serena Lopez
- Centre Hospitalier Universitaire de Nantes, Competence Center for Rare Oral and Dental Diseases, Nantes, France
| | - Corinne Tardieu
- APHM, Hôpitaux Universitaires de Marseille, Hôpital Timone, Competence Center for Rare Oral and Dental Diseases, Marseille, France
| | - Béatrice Thivichon-Prince
- Centre Hospitalier Universitaire de Lyon, Competence Center for Rare Oral and Dental Diseases, Lyon, France
| | | | - Tatjana Dostalova
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | - Milan Macek
- Department of Stomatology (TD) and Department of Biology and Medical Genetics (MM) Charles University 2nd Faculty of Medicine and Motol University Hospital, Prague, Czechia
| | | | - Mustapha El Alloussi
- Faculty of Dentistry, International University of Rabat, CReSS Centre de recherche en Sciences de la Santé, Rabat, Morocco
| | - Leila Qebibo
- Unité de génétique médicale et d’oncogénétique, CHU Hassan II, Fes, Morocco
| | | | | | - Blanca Urzúa Orellana
- Instituto de Investigación en Ciencias Odontológicas, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - Marie-Cécile Manière
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
| | - Bénédicte Gérard
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
| | - Isaac Maximiliano Bugueno
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Hôpitaux Universitaires de Strasbourg (HUS), Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filiére Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
| | - Virginie Laugel-Haushalter
- Université de Strasbourg, Faculté de Chirurgie Dentaire, Strasbourg, France
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), IN-SERM U1258, CNRS- UMR7104, Illkirch, France
- Hôpitaux Universitaires de Strasbourg, Laboratoires de diagnostic génétique, Institut de Génétique Médicale d’Alsace, Strasbourg, France
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3
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Inoue A, Kiyoshima T, Yoshizaki K, Nakatomi C, Nakatomi M, Ohshima H, Shin M, Gao J, Tsuru K, Okabe K, Nakamura I, Honda H, Matsuda M, Takahashi I, Jimi E. Deletion of epithelial cell-specific p130Cas impairs the maturation stage of amelogenesis. Bone 2022; 154:116210. [PMID: 34592494 DOI: 10.1016/j.bone.2021.116210] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 11/02/2022]
Abstract
Amelogenesis consists of secretory, transition, maturation, and post-maturation stages, and the morphological changes of ameloblasts at each stage are closely related to their function. p130 Crk-associated substrate (Cas) is a scaffold protein that modulates essential cellular processes, including cell adhesion, cytoskeletal changes, and polarization. The expression of p130Cas was observed from the secretory stage to the maturation stage in ameloblasts. Epithelial cell-specific p130Cas-deficient (p130CasΔepi-) mice exhibited enamel hypomineralization with chalk-like white mandibular incisors in young mice and attrition in aged mouse molars. A micro-computed tomography analysis and Vickers micro-hardness testing showed thinner enamel, lower enamel mineral density and hardness in p130CasΔepi- mice in comparison to p130Casflox/flox mice. Scanning electron microscopy, and an energy dispersive X-ray spectroscopy analysis indicated the disturbance of the enamel rod structure and lower Ca and P contents in p130CasΔepi- mice, respectively. The disorganized arrangement of ameloblasts, especially in the maturation stage, was observed in p130CasΔepi- mice. Furthermore, expression levels of enamel matrix proteins, such as amelogenin and ameloblastin in the secretory stage, and functional markers, such as alkaline phosphatase and iron accumulation, and Na+/Ca2++K+-exchanger in the maturation stage were reduced in p130CasΔepi- mice. These findings suggest that p130Cas plays important roles in amelogenesis (197 words).
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Affiliation(s)
- Akane Inoue
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Tamotsu Kiyoshima
- Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Chihiro Nakatomi
- Division of Physiology, Kyushu Dental University, 2-6-1 Manazuru, Kokurakita-ku, Kitakyushu 803-8580, Japan
| | - Mitsushiro Nakatomi
- Department of Human, Information and Life Sciences, School of Health Sciences, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan
| | - Hayato Ohshima
- Division of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Chuo-ku, Niigata 951-8514, Japan
| | - Masashi Shin
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan; Oral Medicine Center, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Jing Gao
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Kanji Tsuru
- Section of Bioengineering, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Koji Okabe
- Department of Physiological Sciences and Molecular Biology, Fukuoka Dental College, 2-5-1 Tamura, Sawara-ku, Fukuoka 814-0175, Japan
| | - Ichiro Nakamura
- Department of Rehabilitation, Yugawara Hospital, Japan Community Health Care Organization, 2-21-6 Chuo, Yugawara, Ashigara-shimo, Kanagawa 259-0396, Japan
| | - Hiroaki Honda
- Field of Human Disease Models, Major in Advanced Life Sciences and Medicine, Institute of Laboratory Animals, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ku, Tokyo 162-8666, Japan
| | - Miho Matsuda
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Ichiro Takahashi
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
| | - Eijiro Jimi
- Laboratory of Molecular and Cellular Biochemistry, Division of Oral Biological Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan; Oral Health/Brain Health/Total Health Research Center, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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4
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Sriwattanapong K, Nitayavardhana I, Theerapanon T, Thaweesapphithak S, Chantarawaratit PO, Garuyakich R, Phokaew C, Porntaveetus T, Shotelersuk V. Age-related dental phenotypes and tooth characteristics of FAM83H-associated hypocalcified amelogenesis imperfecta. Oral Dis 2021; 28:734-744. [PMID: 33486840 DOI: 10.1111/odi.13780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 01/06/2021] [Accepted: 01/18/2021] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Autosomal-dominant hypocalcified amelogenesis imperfecta (ADHCAI) shows phenotypic heterogeneity. Our aim was to characterise the ADHCAI phenotypes, tooth properties and genotypes. METHODS Three unrelated ADHCAI probands and seven additional affected members of the three families were recruited. Mutations were identified by exome and Sanger sequencing, and haplotypes by SNP array. Tooth colour, roughness, density, nanohardness, minerals and ultrastructure were investigated. RESULTS Ten participants were heterozygous for the FAM83H mutation c.1387C>T (p.Gln463*). All shared a 3.43 Mbp region on chromosome 8q24.3 encompassing the FAM83H variant, indicating a common ancestry. The c.1387C>T was estimated to be 23.8 generations or 600 years. The FAM83H enamel had higher roughness and lower lightness, density, nanohardness, and calcium and phosphorus levels than controls. Blunted enamel rods, wide interrod spaces and disorganised dentinoenamel junctions were observed. Evaluating the patients with the same mutation and reviewing others with different mutations in FAM83H revealed that the FAM83H heterogeneous phenotypes are age-influenced. Tooth colour and surface texture change with ageing. CONCLUSIONS FAM83H enamel demonstrated decreased lightness, density, hardness, calcium, phosphorus and defective ultrastructure. We have identified that the phenotypic variation in FAM83H-associated ADHCAI is age-related. Awareness of the correlation between age and clinical features of FAM83H-ADHCAI can help dentists make an accurate diagnosis.
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Affiliation(s)
- Kanokwan Sriwattanapong
- Genomics and Precision Dentistry Research Unit, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Issree Nitayavardhana
- Geriatric Dentistry and Special Patients Care Clinic, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Thanakorn Theerapanon
- Genomics and Precision Dentistry Research Unit, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Sermporn Thaweesapphithak
- Center of Excellence in Regenerative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | | | - Rakkierti Garuyakich
- Geriatric Dentistry and Special Patients Care Clinic, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Chureerat Phokaew
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
| | - Thantrira Porntaveetus
- Genomics and Precision Dentistry Research Unit, Department of Physiology, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand.,Geriatric Dentistry and Special Patients Care Clinic, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Vorasuk Shotelersuk
- Center of Excellence for Medical Genomics, Medical Genomics Cluster, Department of Pediatrics, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.,Excellence Center for Genomics and Precision Medicine, King Chulalongkorn Memorial Hospital, The Thai Red Cross Society, Bangkok, Thailand
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5
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Tachie-Menson T, Gázquez-Gutiérrez A, Fulcher LJ, Macartney TJ, Wood NT, Varghese J, Gourlay R, Soares RF, Sapkota GP. Characterisation of the biochemical and cellular roles of native and pathogenic amelogenesis imperfecta mutants of FAM83H. Cell Signal 2020; 72:109632. [PMID: 32289446 PMCID: PMC7284315 DOI: 10.1016/j.cellsig.2020.109632] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 04/06/2020] [Accepted: 04/06/2020] [Indexed: 12/27/2022]
Abstract
The majority of mutations identified in patients with amelogenesis imperfecta have been mapped to FAM83H. As FAM83H expression is not limited to the enamel, how FAM83H contributes to amelogenesis is still largely unknown. We previously reported that members of the FAM83 family of proteins interact with and regulate the subcellular distribution of the promiscuous serine-threonine protein kinase CK1 family, through their shared N-terminal DUF1669 domains. FAM83H co-localises with CK1 isoforms to speckle-like structures in both the cytoplasm and nucleus. In this report, we show FAM83H, unlike other FAM83 proteins, interacts and colocalises with NCK1/2 tyrosine kinase adaptor proteins. This interaction is mediated by proline-rich motifs within the C-terminus of FAM83H, specifically interacting with the second and third SH3 domains of NCK1/2. Moreover, FAM83H pathogenic AI mutant proteins, which trigger C-terminal truncations of FAM83H, retain their interactions with CK1 isoforms but lose interaction with NCK1/2. These AI mutant FAM83H proteins acquire a nuclear localisation, and recruit CK1 isoforms to the nucleus where CK1 retains its kinase activity. As understanding the constituents of the FAM83H-localised speckles may hold the key to unravelling potential substrates of FAM83H-associated CK1 substrates, we employed a TurboID-based proximity labelling approach and uncovered several proteins including Iporin and BAG3 as potential constituents of the speckles.
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Affiliation(s)
- Theresa Tachie-Menson
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Ana Gázquez-Gutiérrez
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom; University of Seville, Av. Sanchez Pizjuan, s/n, 41009, Seville, Spain
| | - Luke J Fulcher
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Thomas J Macartney
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Nicola T Wood
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Joby Varghese
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Robert Gourlay
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Renata F Soares
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Gopal P Sapkota
- Medical Research Council Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom.
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6
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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: 157] [Impact Index Per Article: 22.4] [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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7
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Wang SK, Hu Y, Yang J, Smith CE, Richardson AS, Yamakoshi Y, Lee YL, Seymen F, Koruyucu M, Gencay K, Lee M, Choi M, Kim JW, Hu JCC, Simmer JP. Fam83h null mice support a neomorphic mechanism for human ADHCAI. Mol Genet Genomic Med 2015; 4:46-67. [PMID: 26788537 PMCID: PMC4707031 DOI: 10.1002/mgg3.178] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/17/2015] [Accepted: 08/18/2015] [Indexed: 11/10/2022] Open
Abstract
Truncation mutations in FAM83H (family with sequence similarity 83, member H) cause autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI), but little is known about FAM83H function and the pathogenesis of ADHCAI. We recruited three ADHCAI families and identified two novel (p.Gln457*; p.Lys639*) and one previously documented (p.Q452*) disease‐causing FAM83H mutations. We generated and characterized Fam83h‐knockout/lacZ‐knockin mice. Surprisingly, enamel thickness, density, Knoop hardness, morphology, and prism patterns were similar in Fam83h+/+, Fam83h+/−, and Fam83h−/− mice. The histology of ameloblasts in all stages of development, in both molars and incisors, was virtually identical in all three genotypes and showed no signs of pathology, although the Fam83h−/− mice usually died after 2 weeks and rarely survived to 7 weeks. LacZ expression in the knockin mice was used to report Fam83h expression in the epithelial tissues of many organs, notably in skin and hair follicles, which manifested a disease phenotype. Pull‐down studies determined that FAM83H dimerizes through its N‐terminal phospholipase D‐like (PLD‐like) domain and identified potential FAM83H interacting proteins. Casein kinase 1 (CK1) interacts with the FAM83H PLD‐like domain via an F270‐X‐X‐X‐F274‐X‐X‐X‐F278 motif. CK1 can phosphorylate FAM83H in vitro, and many phosphorylation sites were identified in the FAM83H C‐terminus. Truncation of FAM83H alters its subcellular localization and that of CK1. Our results support the conclusion that FAM83H is not necessary for proper dental enamel formation in mice, but may act as a scaffold protein that localizes CK1. ADHCAI is likely caused by gain‐of‐function effects mediated by truncated FAM83H, which potentially mislocalizes CK1 as part of its pathological mechanism.
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Affiliation(s)
- Shih-Kai Wang
- Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Pl. Ann Arbor Michigan 48108
| | - Yuanyuan Hu
- Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Pl. Ann Arbor Michigan 48108
| | - Jie Yang
- Department of Biologic and Materials SciencesUniversity of Michigan School of Dentistry1210 Eisenhower Pl.Ann ArborMichigan48108; Department of Pediatric DentistrySchool and Hospital of StomatologyPeking University22 South Avenue ZhongguancunHaidian DistrictBeijing100081China
| | - Charles E Smith
- Facility for Electron Microscopy Research Department of Anatomy and Cell Biology and Faculty of Dentistry McGill University 3640 University Street Montreal Quebec H3A 2C7 Canada
| | - Amelia S Richardson
- Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Pl. Ann Arbor Michigan 48108
| | - Yasuo Yamakoshi
- Department of Biochemistry and Molecular Biology School of Dental Medicine Tsurumi University 2-1-3 Tsurumi Tsurumi-ku Yokohama 230-8501 Japan
| | - Yuan-Ling Lee
- Graduate Institute of Clinical Dentistry National Taiwan University No. 1, Chang-Te St Taipei 10048 Taiwan
| | - Figen Seymen
- Department of Pedodontics Faculty of Dentistry Istanbul University Istanbul Turkey
| | - Mine Koruyucu
- Department of Pedodontics Faculty of Dentistry Istanbul University Istanbul Turkey
| | - Koray Gencay
- Department of Pedodontics Faculty of Dentistry Istanbul University Istanbul Turkey
| | - Moses Lee
- Department of Biomedical Sciences Seoul National University College of Medicine 275-1 Yongon-dong Chongno-gu Seoul 110-768 Korea
| | - Murim Choi
- Department of Biomedical Sciences Seoul National University College of Medicine 275-1 Yongon-dong Chongno-gu Seoul 110-768 Korea
| | - Jung-Wook Kim
- Department of Pediatric Dentistry & Dental Research Institute School of Dentistry Seoul National University 275-1 Yongon-dong Chongno-gu Seoul 110-768 Korea
| | - Jan C-C Hu
- Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Pl. Ann Arbor Michigan 48108
| | - James P Simmer
- Department of Biologic and Materials Sciences University of Michigan School of Dentistry 1210 Eisenhower Pl. Ann Arbor Michigan 48108
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8
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Li L, Shu Y, Lou B, Wu H. Candidate-gene exclusion in a family with inherited non-syndromic dental disorders. Gene 2012; 511:420-6. [PMID: 23018043 DOI: 10.1016/j.gene.2012.09.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2012] [Revised: 08/15/2012] [Accepted: 09/12/2012] [Indexed: 01/06/2023]
Abstract
OBJECTIVES Amelogenesis imperfecta, dentinogenesis imperfecta, and dentin dysplasia are the most common non-syndromic dental disorders. In this study, we analysed and localised the gene(s) responsible for inherited non-syndromic dental disorders in a Chinese family. METHODS This study identified and researched non-syndromic dental disorders in a four-generation Chinese family, including four affected individuals whose clinical phenotype was atypical. Linkage analysis with seven polymorphic markers that localise to six different autochromosomes showed that the family was linked through chromosome 4q. All exons and exon-intron boundaries of dentin sialophosphoprotein (DSPP), enamelin (ENAM), and ameloblastin (AMBN), which are located on chromosome 4q, were sequenced in nine of the family members. RESULTS Direct DNA sequence analysis revealed the existence of a G to A transversion in exon 4 (g.13081786G>A, c.727G>A, p.Asp243Asn, based on reference sequences NM_014208.3) of the DSPP gene, and this sequence variation correlated exactly with the presence of the disease. CONCLUSION These results indicate that mutation p.Asp243Asn is a highly probable cause of non-syndromic dental disorder in this Chinese family. The presence of symptom heterogeneity is possible, as the clinical classification system is hampered by the lack of close correlation between the subtype and the molecular defect.
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Affiliation(s)
- Li Li
- West China College of Stomatology, Sichuan University, Chengdu, Sichuan 610041, China
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9
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Urzúa B, Ortega-Pinto A, Farias DA, Franco E, Morales-Bozo I, Moncada G, Escobar-Pezoa N, Scholz U, Cifuentes V. A multidisciplinary approach for the diagnosis of hypocalcified amelogenesis imperfecta in two Chilean families. Acta Odontol Scand 2012; 70:7-14. [PMID: 21504268 DOI: 10.3109/00016357.2011.574973] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The purpose of this study was to conduct a multidisciplinary analysis of a specific type of tooth enamel disturbance (amelogenesis imperfecta) affecting two Chilean families to obtain a precise diagnosis and to investigate possible underlying mutations. MATERIALS AND METHODS Two non-related families affected with amelogenesis imperfecta were evaluated with clinical, radiographic and histopathological methods. Furthermore, pedigrees of both families were constructed and the presence of eight mutations in the enamelin gene (ENAM) and three mutations in the enamelysin gene (MMP-20) were investigated by PCR and direct sequencing. RESULTS In the two affected patients, the dental malformation presented as soft and easily disintegrated enamel and exposed dark dentin. Neither of the affected individuals presented with a dental and skeletal open bite. Histologically, a high level of an organic matrix with prismatic organization was found. Genetic analysis indicated that the condition is autosomal recessive in one family and either autosomal recessive or due to a new mutation in the other family. Molecular mutational analysis revealed that none of the eight mutations previously described in the ENAM gene or the three mutations in the MMP-20 gene were present in the probands. CONCLUSION A multidisciplinary analysis allowed for a diagnosis of hypocalcified amelogenesis imperfecta, Witkop type III, which was unrelated to previously described mutations in the ENAM or MMP-20 genes.
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Affiliation(s)
- Blanca Urzúa
- Department of Physical and Chemical Sciences, University of Chile, Santiago de Chile, Chile.
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10
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Chaudhary M, Dixit S, Singh A, Kunte S. Amelogenesis imperfecta: Report of a case and review of literature. J Oral Maxillofac Pathol 2011; 13:70-7. [PMID: 21887005 PMCID: PMC3162864 DOI: 10.4103/0973-029x.57673] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a diverse collection of inherited diseases that exhibit quantitative or qualitative tooth enamel defects in the absence of systemic manifestations. Also known by varied names such as Hereditary enamel dysplasia, Hereditary brown enamel, Hereditary brown opalescent teeth, this defect is entirely ectodermal, since mesodermal components of the teeth are basically normal. The AI trait can be transmitted by either autosomal dominant, autosomal recessive, or X-linked modes of inheritance. Genes implicated in autosomal forms are genes encoding enamel matrix proteins, namely: enamelin and ameloblastin, tuftelin, MMP-20 and kallikrein - 4. This article presents a case reported to Dr. D. Y. Patil, Dental College and Hospital, Pune, India, along with a review of this often seen clinical entity.
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Affiliation(s)
- Mayur Chaudhary
- Department of Oral Pathology, New Horizon Dental College and Research Institute, Sakri, Bilaspur, India
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11
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Haubek D, Gjørup H, Jensen LG, Juncker I, Nyegaard M, Børglum AD, Poulsen S, Hertz JM. Limited phenotypic variation of hypocalcified amelogenesis imperfecta in a Danish five-generation family with a novel FAM83H nonsense mutation. Int J Paediatr Dent 2011; 21:407-12. [PMID: 21702852 DOI: 10.1111/j.1365-263x.2011.01142.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND. Autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI) is a disease with severe dental manifestations. OBJECTIVES. The aims were by means of a genome-wide linkage scan to search for the gene underlying the ADHCAI phenotype in a Danish five-generation family and to study the phenotypic variation of the enamel in affected family members. RESULTS. Significant linkage was found to a locus at chromosome 8q24.3 comprising the gene FAM83H identified to be responsible for ADHCAI in other families. Subsequent sequencing of FAM83H in affected family members revealed a novel nonsense mutation, p.Y302X. Limited phenotypic variation was found among affected family members with loss of translucency and discoloration of the enamel. Extensive posteruptive loss of enamel was found in all teeth of affected subjects. The tip of the cusps on the premolars and molars and a zone along the gingival margin seemed resistant to posteruptive loss of enamel. We have screened FAM83H in another five unrelated Danish patients with a phenotype of ADHCAI similar to that in the five-generation family, and identified a de novo FAM83H nonsense mutation, p.Q452X in one of these patients. CONCLUSION. We have identified a FAM83H mutation in two of six unrelated families with ADHCAI and found limited phenotypic variation of the enamel in these patients.
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Affiliation(s)
- Dorte Haubek
- Department of Pediatric Dentistry, School of Dentistry, Aarhus University, Denmark.
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12
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Urzúa B, Ortega-Pinto A, Morales-Bozo I, Rojas-Alcayaga G, Cifuentes V. Defining a new candidate gene for amelogenesis imperfecta: from molecular genetics to biochemistry. Biochem Genet 2010; 49:104-21. [PMID: 21127961 DOI: 10.1007/s10528-010-9392-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 07/23/2010] [Indexed: 10/18/2022]
Abstract
Amelogenesis imperfecta is a group of genetic conditions that affect the structure and clinical appearance of tooth enamel. The types (hypoplastic, hypocalcified, and hypomature) are correlated with defects in different stages of the process of enamel synthesis. Autosomal dominant, recessive, and X-linked types have been previously described. These disorders are considered clinically and genetically heterogeneous in etiology, involving a variety of genes, such as AMELX, ENAM, DLX3, FAM83H, MMP-20, KLK4, and WDR72. The mutations identified within these causal genes explain less than half of all cases of amelogenesis imperfecta. Most of the candidate and causal genes currently identified encode proteins involved in enamel synthesis. We think it is necessary to refocus the search for candidate genes using biochemical processes. This review provides theoretical evidence that the human SLC4A4 gene (sodium bicarbonate cotransporter) may be a new candidate gene.
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Affiliation(s)
- Blanca Urzúa
- Department of Physical and Chemical Sciences, Faculty of Dentistry, University of Chile, Santiago, Chile.
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13
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Dashash M, Bazrafshani MR, Poulton K, Jaber S, Naeem E, Blinkhorn AS. Enamelin/ameloblastin gene polymorphisms in autosomal amelogenesis imperfecta among Syrian families. ACTA ACUST UNITED AC 2010; 2:16-22. [DOI: 10.1111/j.2041-1626.2010.00038.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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14
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Lee SK, Seymen F, Lee KE, Kang HY, Yildirim M, Tuna EB, Gencay K, Hwang YH, Nam KH, De La Garza RJ, Hu JCC, Simmer JP, Kim JW. Novel WDR72 mutation and cytoplasmic localization. J Dent Res 2010; 89:1378-82. [PMID: 20938048 DOI: 10.1177/0022034510382117] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The proven candidate genes for amelogenesis imperfecta (AI) are AMELX, ENAM, MMP20, KLK4, FAM83H, and WDR72. We performed mutation analyses on seven families with hypomaturation AI. A novel WDR72 dinucleotide deletion mutation (g.57,426_57,427delAT; c.1467_ 1468delAT; p.V491fsX497) was identified in both alleles of probands from Mexico and Turkey. Haplotype analyses showed that the mutations arose independently in the two families. The disease perfectly segregated with the genotype. Only persons with both copies of the mutant allele were affected. Their hypomineralized enamel suffered attrition and orange-brown staining following eruption. Expression of WDR72 fused to green fluorescent protein showed a cytoplasmic localization exclusively and was absent from the nucleus. We conclude that WDR72 is a cytoplasmic protein that is critical for dental enamel formation.
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Affiliation(s)
- S-K Lee
- Department of Cell and Developmental Biology, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
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15
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Ding Y, Estrella MRP, Hu YY, Chan HL, Zhang HD, Kim JW, Simmer JP, Hu JCC. Fam83h is associated with intracellular vesicles and ADHCAI. J Dent Res 2009; 88:991-6. [PMID: 19828885 DOI: 10.1177/0022034509349454] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Defects in FAM83H on human chromosome 8q24.3 cause autosomal-dominant hypocalcified amelogenesis imperfecta (ADHCAI). FAM83H does not encode a recognizable signal peptide, so we predicted that the Fam83h protein functions within the cell. We tested this hypothesis by constitutively expressing mouse Fam83h with green fluorescent protein (GFP) fused to its C-terminus in HEK293 and HeLa cell lines. Green fluorescent signal from the Fam83h-GFP fusion protein was associated with perinuclear vesicles, usually in the vicinity of the Golgi apparatus. No signal was observed within the nucleus. In addition, we identified FAM83H nonsense mutations in Hispanic (C1330C>T; p.Q444X) and Caucasian (c.1192C>T; p.Q398X) families with ADHCAI. We conclude that Fam83h localizes in the intracellular environment, is associated with vesicles, and plays an important role in dental enamel formation. FAM83H is the first gene involved in the etiology of amelogenesis imperfecta (AI) that does not encode a secreted protein.
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Affiliation(s)
- Y Ding
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, 1011 N. University, Ann Arbor, MI 48109-1078, USA
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16
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Wright JT, Hart TC, Hart PS, Simmons D, Suggs C, Daley B, Simmer J, Hu J, Bartlett JD, Li Y, Yuan ZA, Seow WK, Gibson CW. Human and mouse enamel phenotypes resulting from mutation or altered expression of AMEL, ENAM, MMP20 and KLK4. Cells Tissues Organs 2008; 189:224-9. [PMID: 18714142 PMCID: PMC2754863 DOI: 10.1159/000151378] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Amelogenesis imperfecta (AI) is caused by AMEL, ENAM, MMP20 and KLK4 gene mutations. Mice lacking expression of the AmelX, Enam and Mmp20 genes have been generated. These mouse models provide tools for understanding enamel formation and AI pathogenesis. This study describes the AI phenotypes and relates them to their mouse model counterparts. Human AI phenotypes were determined in a clinical population of AI families and published cases. Human and murine teeth were evaluated using light and electron microscopy. A total of 463 individuals from 54 families were evaluated and mutations in the AMEL, ENAM and KLK4 genes were identified. The majority of human mutations for genes coding enamel nonproteinase proteins (AMEL and ENAM) resulted in variable hypoplasia ranging from local pitting to a marked, generalized enamel thinning. Specific AMEL mutations were associated with abnormal mineralization and maturation defects. Amel and Enam null murine models displayed marked enamel hypoplasia and a complete loss of prism structure. Human mutations in genes coding for the enamel proteinases (MMP20 and KLK4) cause variable degrees of hypomineralization. The murine Mmp20 null mouse exhibits both hypoplastic and hypomineralized defects. The currently available Amel and Enam mouse models for AI exhibit enamel phenotypes (hypoplastic) that are generally similar to those seen in humans. Mmp20 null mice have a greater degree of hypoplasia than humans with MMP20 mutations. Mice lacking expression of the currently known genes associated with the human AI conditions provide useful models for understanding the pathogenesis of these conditions.
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Affiliation(s)
- J Timothy Wright
- Department of Pediatric Dentistry, University of North Carolina, Chapel Hill, NC 27599, USA.
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17
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Lee SK, Hu JCC, Bartlett JD, Lee KE, Lin BPJ, Simmer JP, Kim JW. Mutational spectrum of FAM83H: the C-terminal portion is required for tooth enamel calcification. Hum Mutat 2008; 29:E95-9. [PMID: 18484629 PMCID: PMC2889227 DOI: 10.1002/humu.20789] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Dental enamel forms through the concerted activities of specialized extracellular matrix proteins, including amelogenin, enamelin, MMP20, and KLK4. Defects in the genes encoding these proteins cause non-syndromic inherited enamel malformations collectively designated as amelogenesis imperfecta (AI). These genes, however, account for only about a quarter of all AI cases. Recently we identified mutations in FAM83H that caused autosomal dominant hypocalcified amelogenesis imperfecta (ADHCAI). Unlike other genes that cause AI, FAM83 H does not encode an extracellular matrix protein. Its location inside the cell is completely unknown, as is its function. We here report novel FAM83H mutations in four kindreds with ADHCAI. All are nonsense mutations in the last exon (c.1243G>T, p.E415X; c.891T>A, p.Y297X; c.1380G>A, p.W460X; and c.2029C>T, p.Q677X). These mutations delete between 503 and 883 amino acids from the C-terminus of a protein normally comprised of 1179 residues. The reason these mutations cause such extreme defects in the enamel layer without affecting other parts of the body is not known yet. However it seems evident that the large C-terminal part of the protein is essential for proper enamel calcification.
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Affiliation(s)
- Sook-Kyung Lee
- Department of Cell and Developmental Biology & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - Jan C-C. Hu
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Lab, 1210 Eisenhower Place, Ann Arbor, MI 48108
| | - John D. Bartlett
- Harvard-Forsyth Department of Oral Biology, Department of Cytokine Biology, The Forsyth Institute, 140 The Fenway, Boston, MA 02115
| | - Kyung-Eun Lee
- Department of Cell and Developmental Biology & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
| | - Brent P-J. Lin
- Department of Growth and Development, University of California, San Francisco, School of Dentistry, San Francisco, CA 94143-0640
| | - James P. Simmer
- Department of Biologic and Materials Sciences, University of Michigan Dental Research Lab, 1210 Eisenhower Place, Ann Arbor, MI 48108
| | - Jung-Wook Kim
- Department of Cell and Developmental Biology & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
- Department of Pediatric Dentistry & Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea
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18
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Bailleul-Forestier I, Molla M, Verloes A, Berdal A. The genetic basis of inherited anomalies of the teeth. Eur J Med Genet 2008; 51:273-91. [PMID: 18499550 DOI: 10.1016/j.ejmg.2008.02.009] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2007] [Accepted: 02/03/2008] [Indexed: 01/10/2023]
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19
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Kim JW, Lee SK, Lee ZH, Park JC, Lee KE, Lee MH, Park JT, Seo BM, Hu JCC, Simmer JP. FAM83H mutations in families with autosomal-dominant hypocalcified amelogenesis imperfecta. Am J Hum Genet 2008; 82:489-94. [PMID: 18252228 DOI: 10.1016/j.ajhg.2007.09.020] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2007] [Revised: 09/25/2007] [Accepted: 09/26/2007] [Indexed: 01/27/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a collection of diverse inherited disorders featuring dental-enamel defects in the absence of significant nondental symptoms. AI phenotypes vary and are categorized as hypoplastic, hypocalcified, and hypomaturation types. Phenotypic specificity to enamel has focused research on genes encoding enamel-matrix proteins. We studied two families with autosomal-dominant hypocalcified AI and have identified nonsense mutations (R325X and Q398X) in the FAM83H gene on chromosome 8q24.3. The mutations perfectly cosegregate with the disease phenotype and demonstrate that FAM83H is required for proper dental-enamel calcification.
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Affiliation(s)
- Jung-Wook Kim
- Department of Cell and Developmental Biology, Dental Research Institute, School of Dentistry, Seoul National University, 275-1 Yongon-dong, Chongno-gu, Seoul 110-768, Korea.
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20
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Crawford PJM, Aldred M, Bloch-Zupan A. Amelogenesis imperfecta. Orphanet J Rare Dis 2007; 2:17. [PMID: 17408482 PMCID: PMC1853073 DOI: 10.1186/1750-1172-2-17] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2007] [Accepted: 04/04/2007] [Indexed: 12/05/2022] Open
Abstract
Amelogenesis imperfecta (AI) represents a group of developmental conditions, genomic in origin, which affect the structure and clinical appearance of enamel of all or nearly all the teeth in a more or less equal manner, and which may be associated with morphologic or biochemical changes elsewhere in the body. The prevalence varies from 1:700 to 1:14,000, according to the populations studied. The enamel may be hypoplastic, hypomineralised or both and teeth affected may be discoloured, sensitive or prone to disintegration. AI exists in isolation or associated with other abnormalities in syndromes. It may show autosomal dominant, autosomal recessive, sex-linked and sporadic inheritance patterns. In families with an X-linked form it has been shown that the disorder may result from mutations in the amelogenin gene, AMELX. The enamelin gene, ENAM, is implicated in the pathogenesis of the dominant forms of AI. Autosomal recessive AI has been reported in families with known consanguinity. Diagnosis is based on the family history, pedigree plotting and meticulous clinical observation. Genetic diagnosis is presently only a research tool. The condition presents problems of socialisation, function and discomfort but may be managed by early vigorous intervention, both preventively and restoratively, with treatment continued throughout childhood and into adult life. In infancy, the primary dentition may be protected by the use of preformed metal crowns on posterior teeth. The longer-term care involves either crowns or, more frequently these days, adhesive, plastic restorations.
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Affiliation(s)
- Peter JM Crawford
- Paediatric Dentistry, Division of Child Dental Health, Dental School, Lower Maudlin St., Bristol BS1 2LY, UK
| | | | - Agnes Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université Louis Pasteur; Centre de référence des manifestations odontologiques des maladies rares, Centre Hospitalier Universitaire, Strasbourg, F-67000, France
- IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Département Génétique et Physiologie; Inserm, U596; CNRS, UMR7104, Illkirch, F-67400 France
- Eastman Dental Institute, Institute of Child Health, University College London, UK
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21
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Santos MCLG, Hart PS, Ramaswami M, Kanno CM, Hart TC, Line SRP. Exclusion of known gene for enamel development in two Brazilian families with amelogenesis imperfecta. Head Face Med 2007; 3:8. [PMID: 17266769 PMCID: PMC1800839 DOI: 10.1186/1746-160x-3-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Accepted: 01/31/2007] [Indexed: 11/10/2022] Open
Abstract
Amelogenesis imperfecta (AI) is a genetically heterogeneous group of diseases that result in defective development of tooth enamel. Mutations in several enamel proteins and proteinases have been associated with AI. The object of this study was to evaluate evidence of etiology for the six major candidate gene loci in two Brazilian families with AI. Genomic DNA was obtained from family members and all exons and exon-intron boundaries of the ENAM, AMBN, AMELX, MMP20, KLK4 and Amelotin gene were amplified and sequenced. Each family was also evaluated for linkage to chromosome regions known to contain genes important in enamel development. The present study indicates that the AI in these two families is not caused by any of the known loci for AI or any of the major candidate genes proposed in the literature. These findings indicate extensive genetic heterogeneity for non-syndromic AI.
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Affiliation(s)
- Maria CLG Santos
- PHD student, Department of Morphology, Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil
| | - P Suzanne Hart
- PHD, National Human Genome Research Institute, NIH Bethesda MD, USA
| | - Mukundhan Ramaswami
- student, National Institute for Dental and Craniofacial Research, Bethesda, MD, USA
| | - Cláudia M Kanno
- School of Dentistry of Aracatuba, University of the State of Sao Paulo, UNESP, Brazil
| | - Thomas C Hart
- PHD, National Institute for Dental and Craniofacial Research, Bethesda, MD, USA
| | - Sergio RP Line
- PHD, Department of Morphology, Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil
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