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Costa CRR, Chalgoumi R, Baker A, Guillou C, Yamaguti PM, Simancas Escorcia V, Abbad L, Amorin BR, de Lima CL, Cannaya V, Benassarou M, Berdal A, Chatziantoniou C, Cases O, Cosette P, Kozyraki R, Acevedo AC. Gingival proteomics reveals the role of TGF beta and YAP/TAZ signaling in Raine syndrome fibrosis. Sci Rep 2024; 14:9497. [PMID: 38664418 PMCID: PMC11045870 DOI: 10.1038/s41598-024-59713-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Raine syndrome (RNS) is a rare autosomal recessive osteosclerotic dysplasia. RNS is caused by loss-of-function disease-causative variants of the FAM20C gene that encodes a kinase that phosphorylates most of the secreted proteins found in the body fluids and extracellular matrix. The most common RNS clinical features are generalized osteosclerosis, facial dysmorphism, intracerebral calcifications and respiratory defects. In non-lethal RNS forms, oral traits include a well-studied hypoplastic amelogenesis imperfecta (AI) and a much less characterized gingival phenotype. We used immunomorphological, biochemical, and siRNA approaches to analyze gingival tissues and primary cultures of gingival fibroblasts of two unrelated, previously reported RNS patients. We showed that fibrosis, pathological gingival calcifications and increased expression of various profibrotic and pro-osteogenic proteins such as POSTN, SPARC and VIM were common findings. Proteomic analysis of differentially expressed proteins demonstrated that proteins involved in extracellular matrix (ECM) regulation and related to the TGFβ/SMAD signaling pathway were increased. Functional analyses confirmed the upregulation of TGFβ/SMAD signaling and subsequently uncovered the involvement of two closely related transcription cofactors important in fibrogenesis, Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). Knocking down of FAM20C confirmed the TGFβ-YAP/TAZ interplay indicating that a profibrotic loop enabled gingival fibrosis in RNS patients. In summary, our in vivo and in vitro data provide a detailed description of the RNS gingival phenotype. They show that gingival fibrosis and calcifications are associated with, and most likely caused by excessed ECM production and disorganization. They furthermore uncover the contribution of increased TGFβ-YAP/TAZ signaling in the pathogenesis of the gingival fibrosis.
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Affiliation(s)
- Cláudio Rodrigues Rezende Costa
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
- Oral Center for Inherited Diseases, University Hospital of Brasília, Oral Histopathology Laboratory, Department of Dentistry, Health Sciences Faculty, University of Brasília (UnB), Brasília, Brazil
- Department of Dentistry, Health Group of Natal (GSAU-NT), Brazilian Air Force, Natal, Parnamirim, Brazil
| | - Rym Chalgoumi
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
| | - Amina Baker
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
| | - Clément Guillou
- Rouen University, INSA Rouen Normandie, CNRS, Normandie Univ, PBS UMR 6270, 76000, Rouen, France
- Rouen University, INSERM US51, CNRS UAR 2026, HeRacles PISSARO, 76000, Rouen, France
| | - Paulo Marcio Yamaguti
- Oral Center for Inherited Diseases, University Hospital of Brasília, Oral Histopathology Laboratory, Department of Dentistry, Health Sciences Faculty, University of Brasília (UnB), Brasília, Brazil
| | - Victor Simancas Escorcia
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
- Grupo de Investigación GENOMA, Universidad del Sinú, Cartagena, Colombia
| | - Lilia Abbad
- MRS1155, INSERM, Sorbonne Université, 75020, Paris, France
| | - Bruna Rabelo Amorin
- Oral Center for Inherited Diseases, University Hospital of Brasília, Oral Histopathology Laboratory, Department of Dentistry, Health Sciences Faculty, University of Brasília (UnB), Brasília, Brazil
| | - Caroline Lourenço de Lima
- Oral Center for Inherited Diseases, University Hospital of Brasília, Oral Histopathology Laboratory, Department of Dentistry, Health Sciences Faculty, University of Brasília (UnB), Brasília, Brazil
| | - Vidjea Cannaya
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
| | - Mourad Benassarou
- Service de Chirurgie Maxillo-Faciale et Stomatologie, Hôpital de La Pitié Salpétrière, Sorbonne Université, 75006, Paris, France
| | - Ariane Berdal
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
- CRMR O-RARES, Hôpital Rothshild, UFR d'Odontologie-Garancière, Université de Paris Cité, 75012, Paris, France
| | | | - Olivier Cases
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
| | - Pascal Cosette
- Rouen University, INSA Rouen Normandie, CNRS, Normandie Univ, PBS UMR 6270, 76000, Rouen, France
- Rouen University, INSERM US51, CNRS UAR 2026, HeRacles PISSARO, 76000, Rouen, France
| | - Renata Kozyraki
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France.
- CRMR O-RARES, Hôpital Rothshild, UFR d'Odontologie-Garancière, Université de Paris Cité, 75012, Paris, France.
- Rouen University, UFR SANTE ROUEN NORMANDIE, Inserm 1096, 76000, Rouen, France.
| | - Ana Carolina Acevedo
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Oral Molecular Pathophysiology, 75006, Paris, France
- Oral Center for Inherited Diseases, University Hospital of Brasília, Oral Histopathology Laboratory, Department of Dentistry, Health Sciences Faculty, University of Brasília (UnB), Brasília, Brazil
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Palma-Lara I, García Alonso-Themann P, Pérez-Durán J, Godínez-Aguilar R, Bonilla-Delgado J, Gómez-Archila D, Espinosa-García AM, Nolasco-Quiroga M, Victoria-Acosta G, López-Ornelas A, Serrano-Bello JC, Olguín-García MG, Palacios-Reyes C. Potential Role of Protein Kinase FAM20C on the Brain in Raine Syndrome, an In Silico Analysis. Int J Mol Sci 2023; 24:ijms24108904. [PMID: 37240249 DOI: 10.3390/ijms24108904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
FAM20C (family with sequence similarity 20, member C) is a serine/threonine-specific protein kinase that is ubiquitously expressed and mainly associated with biomineralization and phosphatemia regulation. It is mostly known due to pathogenic variants causing its deficiency, which results in Raine syndrome (RNS), a sclerosing bone dysplasia with hypophosphatemia. The phenotype is recognized by the skeletal features, which are related to hypophosphorylation of different FAM20C bone-target proteins. However, FAM20C has many targets, including brain proteins and the cerebrospinal fluid phosphoproteome. Individuals with RNS can have developmental delay, intellectual disability, seizures, and structural brain defects, but little is known about FAM20C brain-target-protein dysregulation or about a potential pathogenesis associated with neurologic features. In order to identify the potential FAM20C actions on the brain, an in silico analysis was conducted. Structural and functional defects reported in RNS were described; FAM20C targets and interactors were identified, including their brain expression. Gene ontology of molecular processes, function, and components was completed for these targets, as well as for potential involved signaling pathways and diseases. The BioGRID and Human Protein Atlas databases, the Gorilla tool, and the PANTHER and DisGeNET databases were used. Results show that genes with high expression in the brain are involved in cholesterol and lipoprotein processes, plus axo-dendritic transport and the neuron part. These results could highlight some proteins involved in the neurologic pathogenesis of RNS.
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Affiliation(s)
- Icela Palma-Lara
- Laboratorio de Morfología Celular y Molecular, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México 11340, Mexico
| | | | - Javier Pérez-Durán
- Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Ciudad de México 11000, Mexico
| | | | - José Bonilla-Delgado
- Unidad de Investigación, Hospital Regional de Ixtapaluca, Ixtapaluca 56530, Mexico
- Departamento de Biotecnología, Escuela de Ingeniería y Ciencias, Instituto Tecnológico de Monterrey, Toluca de Lerdo 50110, Mexico
| | - Damián Gómez-Archila
- Departamento de Oncología Quirúrgica, Hospital de Gineco-Obstetricia 3, Centro Médico Nacional "La Raza", Ciudad de México 02990, Mexico
| | | | - Manuel Nolasco-Quiroga
- Coordinación de Enseñanza e Investigación, Clínica Hospital Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Huauchinango 73177, Mexico
| | | | - Adolfo López-Ornelas
- División de Investigación, Hospital Juárez de México, Ciudad de México 11340, Mexico
| | - Juan Carlos Serrano-Bello
- Departamento de Patología Clínica y Experimental, Hospital Infantil de México Federico Gómez, Ciudad de México 06720, Mexico
| | | | - Carmen Palacios-Reyes
- División de Investigación, Hospital Juárez de México, Ciudad de México 11340, Mexico
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Zhang H, Lu Y, Kramer PR, Benson MD, Cheng YSL, Qin C. Intracranial calcification in Fam20c-deficient mice recapitulates human Raine syndrome. Neurosci Lett 2023; 802:137176. [PMID: 36914045 DOI: 10.1016/j.neulet.2023.137176] [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: 12/28/2022] [Revised: 02/26/2023] [Accepted: 03/08/2023] [Indexed: 03/15/2023]
Abstract
FAM20C (family with sequence similarity 20-member C) is a protein kinase that phosphorylates secretory proteins, including the proteins that are essential to the formation and mineralization of calcified tissues. FAM20C loss-of-function mutations cause Raine syndrome in humans, characterized by generalized osteosclerosis, distinctive craniofacial dysmorphism, along with extensive intracranial calcification. Our previous studies revealed that inactivation of Fam20c in mice led to hypophosphatemic rickets. In this study, we examined the expression of Fam20c in the mouse brain and investigated brain calcification in Fam20c-deficient mice. Reverse transcription polymerase chain reaction (RT-PCR), Western-blotting and in situ hybridization analyses demonstrated the broad expression of Fam20c in the mouse brain tissue. X-ray and histological analyses showed that the global deletion of Fam20c (mediated by Sox2-cre) resulted in brain calcification in mice after postnatal 3 months and that the calcifications were bilaterally distributed within the brain. There was mild perifocal microgliosis as well as astrogliosis around calcospherites. The calcifications were first observed in the thalamus, and later in the forebrain and hindbrain. Furthermore, brain-specific deletion (mediated by Nestin-cre) of Fam20c in mice also led to cerebral calcification at an older age (postnatal 6 months), but no obvious skeletal or dental defects. Our results suggest that the local loss of FAM20C function in the brain may directly account for intracranial calcification. We propose that FAM20C plays an essential role in maintaining normal brain homeostasis and preventing ectopic brain calcification.
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Affiliation(s)
- Hua Zhang
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA.
| | - Yongbo Lu
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA
| | - Phillip R Kramer
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA
| | - M Douglas Benson
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA
| | - Yi-Shing L Cheng
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA
| | - Chunlin Qin
- Department of Biomedical Sciences, Texas A&M University School of Dentistry, Dallas, TX 75246, USA
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Chirteș C, Bogliș A, Toth A, Rac C, Bănescu C. Compound heterozygous FAM20C gene variants in a patient with severe Raine syndrome: a case report. Front Genet 2023; 14:1179163. [PMID: 37180977 PMCID: PMC10171555 DOI: 10.3389/fgene.2023.1179163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 04/13/2023] [Indexed: 05/16/2023] Open
Abstract
Raine syndrome is a congenital disorder caused by biallelic mutations in the FAM20C gene. While most diagnosed cases of the syndrome are lethal in the first few months of life, there are also reports of non-lethal cases with Raine syndrome. The characteristic of this syndrome is typical facial dysmorphism and generalized osteosclerosis, as well as possible intracranial calcification, hearing loss, and seizures. We report a case of a 4-day-old patient at the time of examination, born with a distinct facial dysmorphism, short neck, narrow chest, and curved tibia. The parents, affirmative gypsy and non-consanguineous, had a previous male child born with the same phenotype who died at 4 months old. The computed tomography scan revealed choanal atresia, while transfontanelar ultrasound showed hypoplasia of the frontal and temporal lobes, corpus callosum dysgenesis, and multiple areas of intracranial hyperechogenicity. The chest X-Ray revealed generalized increased bone density. A skeletal disorders gene panel was performed which identified two variants in the FAM20C gene: a pathogenic variant c.1291C>T (p.Gln431*) and a likely pathogenic variant (c.1135G>A) (p.Gly379Arg), confirming the clinical diagnosis. The parents were also tested, and each was found to carry one of the variants. The particularity of this case is the severe phenotype in a compound heterozygous case that consists of FAM20C c.1291C>T (p.Gln431*) variant that has recently been reported in the literature. Also, our case is one of the few compound-heterozygous mutations in the FAM20C gene that has been described in a non-consanguineous marriage.
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Affiliation(s)
- Camelia Chirteș
- Laboratory of Genetics, Department of Genetics, Emergency County Hospital, Târgu Mureș, Romania
- *Correspondence: Camelia Chirteș,
| | - Alina Bogliș
- Laboratory of Genetics, Department of Genetics, Emergency County Hospital, Târgu Mureș, Romania
- Department of Genetics, George Emil Palade University of Medicine, Pharmacy, Science and Technology, Târgu Mureș, Romania
| | - Andrea Toth
- Department of Neonatology, Emergency County Hospital, Târgu Mureș, Romania
| | - Corina Rac
- Department of Neonatology, Emergency County Hospital, Târgu Mureș, Romania
| | - Claudia Bănescu
- Laboratory of Genetics, Department of Genetics, Emergency County Hospital, Târgu Mureș, Romania
- Department of Genetics, George Emil Palade University of Medicine, Pharmacy, Science and Technology, Târgu Mureș, Romania
- Center for Advanced Medical and Pharmaceutical Research, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Targu Mures, Târgu Mureș, Romania
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Abstract
Hypophosphatemic rickets typically presents in infancy or early childhood with skeletal deformities and growth plate abnormalities. The most common causes are genetic (such as X-linked hypophosphatemia), and these typically will result in lifelong hypophosphatemia and osteomalacia. Knowledge of phosphate metabolism, including the effects of fibroblast growth factor 23 (FGF23) (an osteocyte produced hormone that downregulates renal phosphate reabsorption and 1,25-dihydroxyvitamin-D (1,25(OH)2D) production), is critical to determining the underlying genetic or acquired causes of hypophosphatemia and to facilitate appropriate treatment. Serum phosphorus should be measured in any child or adult with musculoskeletal complaints suggesting rickets or osteomalacia. Clinical evaluation incudes thorough history, physical examination, laboratory investigations, genetic analysis (especially in the absence of a guiding family history), and imaging to establish etiology and to monitor severity and treatment course. The treatment depends on the underlying cause, but often includes active forms of vitamin D combined with phosphate salts, or anti-FGF23 antibody treatment (burosumab) for X-linked hypophosphatemia. The purpose of this article is to explore the approach to evaluating hypophosphatemic rickets and its treatment options.
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Affiliation(s)
- Sarah A Ackah
- Department of Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Erik A Imel
- Department of Medicine, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Desoutter A, Cases O, Collart Dutilleul PY, Simancas Escorcia V, Cannaya V, Cuisinier F, Kozyraki R. Enamel and dentin in Enamel renal syndrome: A confocal Raman microscopy view. Front Physiol 2022; 13:957110. [PMID: 36091358 PMCID: PMC9453029 DOI: 10.3389/fphys.2022.957110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 08/01/2022] [Indexed: 11/13/2022] Open
Abstract
Enamel Renal Syndrome (ERS) is a rare genetic disorder caused by biallelic mutations in Family with sequence similarity 20A (FAM20A) gene encoding the secretory pathway pseudokinase FAM20A. ERS is characterized by hypoplastic amelogenesis imperfecta (AI), impaired tooth eruption, intra-pulpal calcifications, gingival fibromatosis and nephrocalcinosis of various severity. Previous studies showed that the hypoplastic enamel was also hypomineralized but its chemical composition has not been extensively studied. Furthermore it is currently unclear whether dentinal defects are associated with AI in ERS patients. The objective of the study was to provide a structural and chemical analysis of enamel, dentin and dentin enamel junction (DEJ) in ERS patients carrying four, previously reported, distinct mutations in FAM20A. Chemical cartography obtained with Raman microscopy showed that compared to control samples, ERS enamel composition was severely altered and a cementum-like structure was observed in some cases. Chemical composition of peripulpal dentin was also affected and usual gradient of phosphate intensity, shown in DEJ profile, was absent in ERS samples. DEJ and dentinal anomalies were further confirmed by scanning electron microscopy analysis. In conclusion, our study shows that enamel formation is severely compromised in ERS patients and provides evidence that dentinal defects are an additional feature of the ERS dental phenotype.
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Affiliation(s)
- Alban Desoutter
- Laboratoire Bioingénierie et Nanosciences LBN, Université de Montpellier, Montpellier, France
- *Correspondence: Alban Desoutter,
| | - Olivier Cases
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Laboratory of Oral Molecular Pathophysiology, Paris, France
| | | | - Victor Simancas Escorcia
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Laboratory of Oral Molecular Pathophysiology, Paris, France
- Facultad de Odontología, Universidad de Cartagena, Grupo Interdisciplinario de Investigaciones y Tratamientos Odontológicos Universidad de Cartagena (GITOUC), Cartagena, Colombia
| | - Vidjea Cannaya
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Laboratory of Oral Molecular Pathophysiology, Paris, France
| | - Frédéric Cuisinier
- Laboratoire Bioingénierie et Nanosciences LBN, Université de Montpellier, Montpellier, France
| | - Renata Kozyraki
- Centre de Recherche des Cordeliers, Sorbonne Université, INSERM, Université de Paris Cité, Laboratory of Oral Molecular Pathophysiology, Paris, France
- CRMR O-RARES, Hôpital Rothshild, UFR d’Odontologie-Garancière, Université de Paris Cité, Paris, France
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Rameh G, Megarbane A, Jalbout L, Snaifer E, Saliba S, Nassar A, Chalouhi G. Raine Syndrome: Report of a novel mutation and review of the different antenatal imaging modalities used to diagnose this disease. Prenat Diagn 2022; 42:589-600. [DOI: 10.1002/pd.6138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 03/21/2022] [Accepted: 03/27/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Georges Rameh
- Department of Obstetrics and Gynecology American University of Beirut Medical Center Beirut Lebanon
| | - Andre Megarbane
- Department of Human Genetics Lebanese American University Medical Center Beirut Lebanon
| | - Liliane Jalbout
- Department of Obstetrics and Gynecology Mount Lebanon Hospital Beirut Lebanon
| | - Elie Snaifer
- Department of Obstetrics and Gynecology Saint Georges Hospital Beirut Lebanon
| | - Souha Saliba
- Department of Radiology Hotel Dieu de France Beirut Lebanon
| | - Anwar Nassar
- Department of Obstetrics and Gynecology American University of Beirut Medical Center Beirut Lebanon
| | - Gihad Chalouhi
- Department of Obstetrics and Gynecology American University of Beirut Medical Center Beirut Lebanon
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FAM20C plays a critical role in the development of mouse vertebra. Spine J 2022; 22:337-348. [PMID: 34343663 DOI: 10.1016/j.spinee.2021.07.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/26/2021] [Accepted: 07/27/2021] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Family with sequence similarity 20-member C (FAM20C) is a protein kinase that is responsible for the phosphorylation of many secretory proteins; however, its roles in spine or vertebra development have not be studied. PURPOSE The aim of this investigation is to analyze the roles of FAM20C in vertebra development. STUDY DESIGN/SETTING A mouse study of the Fam20c gene using conditional knockout to assess the effects of its inactivation on vertebra development. METHODS By breeding Sox2-Cre mice with Fam20cflox/flox mice, Sox2-Cre;Fam20cflox/flox mice (abbreviated as cKO mice) are created. X-ray radiography, resin-casted scanning electron microscopy, Hematoxylin and Eosin staining, safranin O staining, Goldner's Masson trichrome staining, Von Kossa staining, tartrate-resistant alkaline phosphatase staining, immunohistochemistry staining, Western Immunoblotting and real-time PCR were employed to characterize the vertebrae of cKO mice compared to the normal control mice. RESULTS Inactivation of Fam20c in mice results in remarkable spine deformity, severe morphology and mineralization defects, altered levels of osteoblast differentiation markers, reduction of activity of the Wnt/β-catenin signaling pathway and reduced level of osteoclastogenesis in the vertebrae. CONCLUSIONS FAM20C plays an essential role in vertebral development; it may regulate vertebral formation through the Wnt/β-catenin signaling pathway. CLINICAL SIGNIFICANCE Mutations in the human FAM20C gene are associated with Raine syndrome. The findings of this study provide valuable clues for the clinical management of Raine syndrome regarding spine manifestations in patients.
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Govitvattana N, Kaku M, Ohyama Y, Jaha H, Lin IP, Mochida H, Pavasant P, Mochida Y. Molecular Cloning of Mouse Homologue of Enamel Protein C4orf26 and Its Phosphorylation by FAM20C. Calcif Tissue Int 2021; 109:445-454. [PMID: 33884476 PMCID: PMC8429244 DOI: 10.1007/s00223-021-00847-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/26/2021] [Indexed: 10/21/2022]
Abstract
It is widely accepted that cellular processes are controlled by protein phosphorylation and has become increasingly clear that protein degradation, localization and conformation as well as protein-protein interaction are the examples of subsequent cellular events modulated by protein phosphorylation. Enamel matrix proteins belong to members of the secretory calcium binding phosphoprotein (SCPP) family clustered on chromosome 4q21, and most of the SCPP phosphoproteins have at least one S-X-E motifs (S; serine, X; any amino acid, E; glutamic acid). It has been reported that mutations in C4orf26 gene, located on chromosome 4q21, are associated with autosomal recessive type of Amelogenesis Imperfecta (AI), a hereditary condition that affects enamel formation/mineralization. The enamel phenotype observed in patients with C4orf26 mutations is hypomineralized and partially hypoplastic, indicating that C4orf26 protein may function at both secretory and maturation stages of amelogenesis. The previous in vitro study showed that the synthetic phosphorylated peptide based on C4orf26 protein sequence accelerates hydroxyapatite nucleation. Here we show the molecular cloning of Gm1045, mouse homologue of C4orf26, which has 2 splicing isoforms. Immunohistochemical analysis demonstrated that the immunolocalization of Gm1045 is mainly observed in enamel matrix in vivo. Our report is the first to show that FAM20C, the Golgi casein kinase, phosphorylates C4orf26 and Gm1045 in cell cultures. The extracellular localization of C4orf26/Gm1045 was regulated by FAM20C kinase activity. Thus, our data point out the biological importance of enamel matrix-kinase control of SCPP phosphoproteins and may have a broad impact on the regulation of amelogenesis and AI.
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Affiliation(s)
- Nattanan Govitvattana
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA
- Department of Pediatric Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Masaru Kaku
- Division of Bio-Prosthodontics, Faculty of Dentistry & Graduate School of Medical and Dental Sciences, Niigata University, Niigata, 951-8514, Japan
| | - Yoshio Ohyama
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA
| | - Haytham Jaha
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA
| | - I-Ping Lin
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA
- Graduate Institute of Clinical Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, 10048, Taiwan
| | - Hanna Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA
| | - Prasit Pavasant
- Center of Excellence in Regenerative Dentistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, 10330, Thailand.
| | - Yoshiyuki Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, 02118, USA.
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10
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FAM20C Overview: Classic and Novel Targets, Pathogenic Variants and Raine Syndrome Phenotypes. Int J Mol Sci 2021; 22:ijms22158039. [PMID: 34360805 PMCID: PMC8348777 DOI: 10.3390/ijms22158039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/16/2021] [Accepted: 07/18/2021] [Indexed: 12/24/2022] Open
Abstract
FAM20C is a gene coding for a protein kinase that targets S-X-E/pS motifs on different phosphoproteins belonging to diverse tissues. Pathogenic variants of FAM20C are responsible for Raine syndrome (RS), initially described as a lethal and congenital osteosclerotic dysplasia characterized by generalized atherosclerosis with periosteal bone formation, characteristic facial dysmorphisms and intracerebral calcifications. The aim of this review is to give an overview of targets and variants of FAM20C as well as RS aspects. We performed a wide phenotypic review focusing on clinical aspects and differences between all lethal (LRS) and non-lethal (NLRS) reported cases, besides the FAM20C pathogenic variant description for each. As new targets of FAM20C kinase have been identified, we reviewed FAM20C targets and their functions in bone and other tissues, with emphasis on novel targets not previously considered. We found the classic lethal and milder non-lethal phenotypes. The milder phenotype is defined by a large spectrum ranging from osteonecrosis to osteosclerosis with additional congenital defects or intellectual disability in some cases. We discuss our current understanding of FAM20C deficiency, its mechanism in RS through classic FAM20C targets in bone tissue and its potential biological relevance through novel targets in non-bone tissues.
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Non-lethal Raine Syndrome Report Lacking Characteristic Clinical Features. J Mol Neurosci 2021; 71:2482-2486. [PMID: 34259997 DOI: 10.1007/s12031-021-01873-z] [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: 05/07/2021] [Accepted: 06/11/2021] [Indexed: 10/20/2022]
Abstract
Raine syndrome is a rare, often lethal autosomal recessive condition marked by congenital malformations that range in severity. Considering that several case reports of this syndrome describe cases of stillbirth or perinatal death, information about the clinical presentation and development of this condition in mild, non-lethal cases is lacking. With that in mind, in this case report, we describe the clinical, oro-dental, and skeletal findings of a 14-year-old Brazilian patient diagnosed with a mild form of non-lethal Raine syndrome. This patient has very mild facial dysmorphia, not displaying hypoplastic nose, micrognathia, low set ears or depressed nasal bridge, which is uncommon even in other mild, non-lethal cases of RS. Furthermore, this patient has bilateral brain calcifications and a series of oro-dental abnormalities, such as amelogenesis imperfecta and recurrent periodontal abcesses. Sanger sequencing of genomic DNA identified a homozygous missense variant c.1487C > T at exon 9 of FAM20C (NM_020223.4) in the patient. The patient's mother carries the same variant but is heterozygous. This variant predicts a proline to leucine substitution in position 496 (p.P496L, NP_064608.2) previously reported, which allows for the phenotypic comparison between these cases. This way, this case report calls attention to how differently RS can appear, highlighting the importance of new non-lethal Raine syndrome case reports to help further determine the phenotypic spectrum of this condition.
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The ABCs of the atypical Fam20 secretory pathway kinases. J Biol Chem 2021; 296:100267. [PMID: 33759783 PMCID: PMC7948968 DOI: 10.1016/j.jbc.2021.100267] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/12/2022] Open
Abstract
The study of extracellular phosphorylation was initiated in late 19th century when the secreted milk protein, casein, and egg-yolk protein, phosvitin, were shown to be phosphorylated. However, it took more than a century to identify Fam20C, which phosphorylates both casein and phosvitin under physiological conditions. This kinase, along with its family members Fam20A and Fam20B, defined a new family with altered amino acid sequences highly atypical from the canonical 540 kinases comprising the kinome. Fam20B is a glycan kinase that phosphorylates xylose residues and triggers peptidoglycan biosynthesis, a role conserved from sponges to human. The protein kinase, Fam20C, conserved from nematodes to humans, phosphorylates well over 100 substrates in the secretory pathway with overall functions postulated to encompass endoplasmic reticulum homeostasis, nutrition, cardiac function, coagulation, and biomineralization. The preferred phosphorylation motif of Fam20C is SxE/pS, and structural studies revealed that related member Fam20A allosterically activates Fam20C by forming a heterodimeric/tetrameric complex. Fam20A, a pseudokinase, is observed only in vertebrates. Loss-of-function genetic alterations in the Fam20 family lead to human diseases such as amelogenesis imperfecta, nephrocalcinosis, lethal and nonlethal forms of Raine syndrome with major skeletal defects, and altered phosphate homeostasis. Together, these three members of the Fam20 family modulate a diverse network of secretory pathway components playing crucial roles in health and disease. The overarching theme of this review is to highlight the progress that has been made in the emerging field of extracellular phosphorylation and the key roles secretory pathway kinases play in an ever-expanding number of cellular processes.
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Hypophosphataemic Rickets Secondary to Raine Syndrome: A Review of the Literature and Case Reports of Three Paediatric Patients' Dental Management. Case Rep Pediatr 2021; 2021:6637180. [PMID: 33505751 PMCID: PMC7808805 DOI: 10.1155/2021/6637180] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Revised: 12/20/2020] [Accepted: 12/23/2020] [Indexed: 12/26/2022] Open
Abstract
Raine Syndrome (RS) also referred to as lethal osteosclerotic bone dysplasia describes an exceptionally rare autosomal recessive disorder with an estimated prevalence of <1 in 1,000,000. Endocrinological manifestations such as hypophosphataemic rickets depict a recent finding within the phenotypic spectrum of nonlethal RS. The dental sequelae of hypophosphataemic rickets are significant. Spontaneous recurrent abscesses on noncarious teeth result in significant odontogenic pain and multiple dental interventions. The dental presentations of nonlethal RS are less widely described within the literature. Amelogenesis Imperfecta (AI), however, was recently postulated as a key characteristic. This article presents the dental manifestations and extensive restorative and oral surgical intervention of three siblings with hypophosphataemic rickets secondary to Raine Syndrome treated at Great Ormond Street Hospital for Children, a tertiary referral hospital.
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Lin JH, Lin IP, Ohyama Y, Mochida H, Kudo A, Kaku M, Mochida Y. FAM20C directly binds to and phosphorylates Periostin. Sci Rep 2020; 10:17155. [PMID: 33051588 PMCID: PMC7555550 DOI: 10.1038/s41598-020-74400-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 09/24/2020] [Indexed: 12/18/2022] Open
Abstract
It is widely accepted that FAM20C functions as a Golgi casein kinase and has large numbers of kinase substrates within the secretory pathway. It has been previously reported that FAM20C is required for maintenance of healthy periodontal tissues. However, there has been no report that any extracellular matrix molecules expressed in periodontal tissues are indeed substrates of FAM20C. In this study, we sought to identify the binding partner(s) of FAM20C. FAM20C wild-type (WT) and its kinase inactive form D478A proteins were generated. These proteins were electrophoresed and the Coomassie Brilliant Blue (CBB)-positive bands were analyzed to identify FAM20C-binding protein(s) by Mass Spectrometry (MS) analysis. Periostin was found by the analysis and the binding between FAM20C and Periostin was investigated in cell cultures and in vitro. We further determined the binding region(s) within Periostin responsible for FAM20C-binding. Immunolocalization of FAM20C and Periostin was examined using mouse periodontium tissues by immunohistochemical analysis. In vitro kinase assay was performed using Periostin and FAM20C proteins to see whether FAM20C phosphorylates Periostin in vitro. We identified Periostin as one of FAM20C-binding proteins by MS analysis. Periostin interacted with FAM20C in a kinase-activity independent manner and the binding was direct in vitro. We further identified the binding domain of FAM20C in Periostin, which was mapped within Fasciclin (Fas) I domain 1-4 of Periostin. Immunolocalization of FAM20C was observed in periodontal ligament (PDL) extracellular matrix where that of Periostin was also immunostained in murine periodontal tissues. FAM20C WT, but not D478A, phosphorylated Periostin in vitro. Consistent with the overlapped expression pattern of FAM20C and Periostin, our data demonstrate for the first time that Periostin is a direct FAM20C-binding partner and that FAM20C phosphorylates Periostin in vitro.
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Affiliation(s)
- Ju-Hsien Lin
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - I-Ping Lin
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
- Graduate Institute of Clinical Dentistry, School of Dentistry, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yoshio Ohyama
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Hanna Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - Akira Kudo
- Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan
| | - Masaru Kaku
- Division of Bio-Prosthodontics, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Yoshiyuki Mochida
- Department of Molecular and Cell Biology, Henry M. Goldman School of Dental Medicine, Boston University, Boston, MA, USA.
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El-Dessouky SH, Abdel-Hamid MS, Abdel-Ghafar SF, Aboulghar MM, Gaafar HM, Fouad M, Ahmed AH, Abdel-Salam GMH. Raine syndrome: Prenatal diagnosis based on recognizable fetal facial features and characteristic intracranial calcification. Prenat Diagn 2020; 40:1578-1597. [PMID: 32833257 DOI: 10.1002/pd.5818] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 08/20/2020] [Accepted: 08/20/2020] [Indexed: 01/21/2023]
Abstract
OBJECTIVE The purpose of this study was to elucidate the facial morphology and the pattern of internal malformations in three fetuses with RS born to first cousins of Egyptian decent. METHODS The fetal ultrasonography findings were highly suggestive of RS leading to targeted Sanger sequencing of FAM20C and postnatal assessment. RESULTS The prenatal ultrasound findings of osteosclerotic skull, exorbitism, hypoplastic nose, midface hypoplasia, small mouth with down-curved corners, and a distinct and recognizable pattern of intracranial calcification were identified in three fetuses with RS. The calcifications were evident specifically around the corpus callosum and/or ventricular walls. Ectopic renal and hepatic calcifications, pulmonary hypoplasia, mild rhizomelic shortening of the upper limbs, intrauterine fractures, and cerebellar hypoplasia were also noted. Molecular analysis identified three novel homozygous variants, two frameshift: [c.456delC (p.Gly153Alafs*34)] in exon 1 and [c.905delT (Phe302Serfs*35)] in exon 4 and one nonsense mutation in exon 10, [c.1557C>G(p.Tyrs519*)]. The three variants were segregated with the phenotype. This is the first description of a phenotype associated with homozygous truncating variants of FAM20C. CONCLUSION RS has characteristic prenatal ultrasound findings which can improve the prenatal identification of this condition and help in guiding the molecular diagnosis and counseling.
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Affiliation(s)
- Sara H El-Dessouky
- Department of Prenatal Diagnosis & Fetal Medicine, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | - Mohamed S Abdel-Hamid
- Department of Medical & Molecular Genetics, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | - Sherif F Abdel-Ghafar
- Department of Medical & Molecular Genetics, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
| | | | | | - Mona Fouad
- Fetal Medicine Unit, Cairo University, Cairo, Egypt
| | - Adel H Ahmed
- Fetal Medicine Unit, Cairo University, Cairo, Egypt
| | - Ghada M H Abdel-Salam
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, National Research Centre, Cairo, Egypt
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Eltan M, Alavanda C, Yavas Abali Z, Ergenekon P, Yalındag Ozturk N, Sakar M, Dagcinar A, Kirkgoz T, Kaygusuz SB, Gokdemir Y, Elcioglu HN, Guran T, Bereket A, Ata P, Turan S. A Rare Cause of Hypophosphatemia: Raine Syndrome Changing Clinical Features with Age. Calcif Tissue Int 2020; 107:96-103. [PMID: 32337609 PMCID: PMC7222149 DOI: 10.1007/s00223-020-00694-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 04/11/2020] [Indexed: 11/29/2022]
Abstract
Raine Syndrome (RS) is caused by biallelic loss-of-function mutations in FAM20C gene and characterized by hypophosphatemia, typical facial and skeletal features. Subperiosteal bone formation and generalized osteosclerosis are the most common radiological findings. Here we present a new case with RS. A 9-month-old male patient on a home-type ventilator was referred for hypophosphatemia. He was born with a weight of 3800 g to non-consanguineous parents. Prenatal ultrasound had demonstrated nasal bone agenesis. A large anterior fontanel, frontal bossing, exophthalmos, hypoplastic nose, high arched palate, low set ears, triangular mouth, and corneal opacification were detected on physical examination. Serial skeletal X-rays revealed diffuse osteosclerosis at birth which was gradually decreased by the age of 5 months with subperiosteal undermineralized bone formation and medullary space of long bone could be distinguishable with bone-within-a-bone appearance. At 9 months of age, hand X-ray revealed cupping of the ulna with loose radial bone margin with minimal fraying and osteopenia. Cranial computed tomography scan showed bilateral periventricular calcification and hydrocephalus in progress. The clinical, laboratory, and radiological examinations were consistent with RS. Molecular analyses revealed a compound heterozygous mutation in FAM20C gene (a known pathogenic mutation, c.1645C > T, p.Arg549Trp; and a novel c.863 + 5 G > C variant). The patient died due to respiratory failure at 17 months of age. This case allowed us to demonstrate natural progression of skeletal features in RS. Furthermore, we have described a novel FAM20C variant causing RS. Previous literature on RS is also reviewed.
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Affiliation(s)
- Mehmet Eltan
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Ceren Alavanda
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Zehra Yavas Abali
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Pinar Ergenekon
- Department of Pediatric Chest Disease, Marmara University School of Medicine, Istanbul, Turkey
| | - Nilufer Yalındag Ozturk
- Department of Pediatric Intensive Care Unit, Marmara University School of Medicine, Istanbul, Turkey
| | - Mustafa Sakar
- Department of Pediatric Neurosurgery, Marmara University School of Medicine, Istanbul, Turkey
| | - Adnan Dagcinar
- Department of Pediatric Neurosurgery, Marmara University School of Medicine, Istanbul, Turkey
| | - Tarik Kirkgoz
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Sare Betul Kaygusuz
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Yasemin Gokdemir
- Department of Pediatric Chest Disease, Marmara University School of Medicine, Istanbul, Turkey
| | - Huriye Nursel Elcioglu
- Department of Pediatric Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulay Guran
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Abdullah Bereket
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Pinar Ata
- Department of Medical Genetics, Marmara University School of Medicine, Istanbul, Turkey
| | - Serap Turan
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey.
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Mameli C, Zichichi G, Mahmood N, Elalaoui SC, Mirza A, Dharmaraj P, Burrone M, Cattaneo E, Sheth J, Gandhi A, Kochar GS, Alkuraya FS, Kabra M, Mercurio G, Zuccotti G. Natural history of non-lethal Raine syndrome during childhood. Orphanet J Rare Dis 2020; 15:93. [PMID: 32299476 PMCID: PMC7164176 DOI: 10.1186/s13023-020-01373-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Raine syndrome (RS) is a rare autosomal recessive disorder caused by biallelic loss-of-function mutations of FAM20C. The most common clinical features are microcephaly, exophthalmos, hypoplastic nose and severe midface hypoplasia, leading to choanal atresia. The radiological findings include generalized osteosclerosis and brain calcifications. RS is usually lethal during the neonatal period due to severe respiratory distress. However, there exists a non-lethal RS form, the phenotype of which is extremely heterogeneous. There is paucity of data about clinical course and life expectancy of these patients. RESULTS This is the first description of follow-up features of non-lethal RS patients. Moreover, we present three unpublished cases. There are five Asian and two Arab patients. All were born to consanguineous parents. The most common neonatal comorbidity was respiratory distress secondary to choanal atresia. A variable degree of neurodevelopmental delay was seen in the majority of our cases and seizures and hearing or vision involvement were also frequent. Neurological and orthopedic issues were the most frequent complications seen at follow-up in our group. Persistent hypophosphatemic rickets was the most striking endocrinological manifestation, which was scarcely responsive to therapy with phosphate salts and alfacalcidol. Life expectancy of our patients goes beyond childhood, with the oldest of those described being 18 years old at present. CONCLUSIONS Manifestations of RS in those surviving the neonatal period are being increasingly recognized. Our study supports previous findings and provides clinical and biochemical observations and data from longer follow up. Finally, we propose multidisciplinary follow up for patients with non-lethal RS.
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Affiliation(s)
- Chiara Mameli
- Department of Pediatrics, Vittore Buzzi Children's Hospital, Department of Biomedical and Clinical Science L. Sacco, Università degli Studi di Milano, Milan, Italy.
| | - Giulia Zichichi
- Department of Pediatrics, Vittore Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy
| | - Nasim Mahmood
- Department of General Paediatrics, Alder Hey Children's Hospital, Liverpool, UK
| | - Siham Chafai Elalaoui
- Centre de Recherche en Génomique des Pathologies Humaines (GENOPATH), Faculté de Médecine et de Pharmacie, Mohammed V University of Rabat, 10100, Rabat, Morocco
| | - Adnan Mirza
- Faculty of Paediatrics, Aga Khan University Hospital, Karachi, Pakistan
| | - Poonam Dharmaraj
- Department of Paediatric Endocrinology, Alder Hey Children's Hospital, Liverpool, UK
| | - Marco Burrone
- Department of Pediatrics, Vittore Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy
| | - Elisa Cattaneo
- Clinical Genetics Service, V. Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy
| | - Jayesh Sheth
- FRIGE-Institute of Human Genetics, Dept of Biochemical and Molecular Genetics, Ahmadabad, Gujarat, and Unique Hospital, Solapur, India
| | - Ajit Gandhi
- FRIGE-Institute of Human Genetics, Dept of Biochemical and Molecular Genetics, Ahmadabad, Gujarat, and Unique Hospital, Solapur, India
| | | | - Fowzan Sami Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Madhulika Kabra
- Division of Genetics, Department of Paediatrics, AIIMS, New Delhi, India
| | - Giuseppe Mercurio
- Department of Pediatrics, Vittore Buzzi Children's Hospital, Università degli Studi di Milano, Milan, Italy
| | - Gianvincenzo Zuccotti
- Department of Pediatrics, Vittore Buzzi Children's Hospital, Department of Biomedical and Clinical Science L. Sacco, Università degli Studi di Milano, Milan, Italy
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Zhang H, Li L, Kesterke MJ, Lu Y, Qin C. High-Phosphate Diet Improved the Skeletal Development of Fam20c-Deficient Mice. Cells Tissues Organs 2020; 208:25-36. [PMID: 32101876 DOI: 10.1159/000506005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 01/19/2020] [Indexed: 12/29/2022] Open
Abstract
FAM20C (family with sequence similarity 20 - member C) is a protein kinase that phosphorylates secretory proteins, including the proteins that are essential to the formation and mineralization of calcified tissues. Previously, we reported that inactivation of Fam20c in mice led to hypophosphatemic rickets/osteomalacia along with increased circulating fibroblast growth factor 23 (FGF23) levels and dental defects. In this study, we examined whether a high-phosphate (hPi) diet could rescue the skeletal defects in Fam20c-deficient mice. Fam20c conditional knockout (cKO) mice were generated by crossing female Fam20c-floxed mice (Fam20cfl/fl) with male Sox2-Cre;Fam20cfl/+ mice. The pregnant female Fam20cfi/fl mice were fed either a normal or hPi diet until the litters were weaned. The cKO and control offspring were continuously given a normal or hPi diet for 4 weeks after weaning. Plain X-ray radiography, micro-CT, histology, immunohistochemistry (FGF23, DMP1, OPN, and SOX9), and in situ hybridization (type II and type X collagen) analyses were performed to evaluate the effects of an hPi diet on the mouse skeleton. Plain X-ray radiography and micro-CT radiography analyses showed that the hPi diet improved the shape and mineral density of the Fam20c-deficient femurs/tibiae, and rescued the growth plate defects in the long bone. Histology analyses further demonstrated that an hPi diet nearly completely rescued the growth plate-widening defects in the long bone and restored the expanded hypertrophic zone to nearly normal width. These results suggested that the hPi diet significantly improved the skeletal development of the Fam20c-deficient mice, implying that hypophosphatemia partially contributed to the skeletal defects in Fam20c-deficient subjects.
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Affiliation(s)
- Hua Zhang
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA,
| | - Lili Li
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA
| | - Matthew J Kesterke
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA
| | - Yongbo Lu
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA
| | - Chunlin Qin
- Department of Biomedical Sciences, Texas A&M University College of Dentistry, Dallas, Texas, USA
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Hernández-Zavala A, Cortés-Camacho F, Palma-Lara I, Godínez-Aguilar R, Espinosa AM, Pérez-Durán J, Villanueva-Ocampo P, Ugarte-Briones C, Serrano-Bello CA, Sánchez-Santiago PJ, Bonilla-Delgado J, Yáñez-López MA, Victoria-Acosta G, López-Ornelas A, García Alonso-Themann P, Moreno J, Palacios-Reyes C. Two Novel FAM20C Variants in A Family with Raine Syndrome. Genes (Basel) 2020; 11:genes11020222. [PMID: 32093234 PMCID: PMC7073523 DOI: 10.3390/genes11020222] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/30/2020] [Accepted: 02/14/2020] [Indexed: 12/14/2022] Open
Abstract
Two siblings from a Mexican family who carried lethal Raine syndrome are presented. A newborn term male (case 1) and his 21 gestational week brother (case 2), with a similar osteosclerotic pattern: generalized osteosclerosis, which is more evident in facial bones and cranial base. Prenatal findings at 21 weeks and histopathological features for case 2 are described. A novel combination of biallelic FAM20C pathogenic variants were detected, a maternal cytosine duplication at position 456 and a paternal deletion of a cytosine in position 474 in exon 1, which change the reading frame with a premature termination at codon 207 and 185 respectively. These changes are in concordance with a negative detection of the protein in liver and kidney as shown in case 2. Necropsy showed absence of pancreatic Langerhans Islets, which are reported here for the first time. Corpus callosum absence is added to the few reported cases of brain defects in Raine syndrome. This report shows two new FAM20C variants not described previously, and negative protein detection in the liver and the kidney. We highlight that lethal Raine syndrome is well defined as early as 21 weeks, including mineralization defects and craniofacial features. Pancreas and brain defects found here in FAM20C deficiency extend the functional spectrum of this protein to previously unknown organs.
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Affiliation(s)
- Araceli Hernández-Zavala
- Laboratory of Cellular and Molecular Morphology, Section of Postgraduate Studies and Research, Escuela Superior de Medicina, Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Mexico City 11340, Mexico; (A.H.-Z.); (F.C.-C.); (I.P.-L.)
| | - Fernando Cortés-Camacho
- Laboratory of Cellular and Molecular Morphology, Section of Postgraduate Studies and Research, Escuela Superior de Medicina, Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Mexico City 11340, Mexico; (A.H.-Z.); (F.C.-C.); (I.P.-L.)
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Icela Palma-Lara
- Laboratory of Cellular and Molecular Morphology, Section of Postgraduate Studies and Research, Escuela Superior de Medicina, Instituto Politécnico Nacional, Salvador Díaz Mirón esq. Plan de San Luis S/N, Miguel Hidalgo, Casco de Santo Tomas, Mexico City 11340, Mexico; (A.H.-Z.); (F.C.-C.); (I.P.-L.)
| | - Ricardo Godínez-Aguilar
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Ana María Espinosa
- Service of Clinical Pharmacology, Hospital General de México, Dr. Balmis 148, Doctores, Cuauhtémoc, Mexico City 06720, Mexico;
| | - Javier Pérez-Durán
- National Institute of Perinatology, Calle Montes Urales 800, Lomas - Virreyes, Lomas de Chapultepec IV Section, Miguel Hidalgo, Mexico City 11000, Mexico; (J.P.-D.); (P.G.A.-T.)
| | - Patricia Villanueva-Ocampo
- Deparment of Ginecology, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico;
| | - Carlos Ugarte-Briones
- Department of Pathology, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (C.U.-B.); (C.A.S.-B.); (P.J.S.-S.)
| | - Carlos Alberto Serrano-Bello
- Department of Pathology, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (C.U.-B.); (C.A.S.-B.); (P.J.S.-S.)
| | - Paula Jesús Sánchez-Santiago
- Department of Pathology, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (C.U.-B.); (C.A.S.-B.); (P.J.S.-S.)
| | - José Bonilla-Delgado
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Marco Antonio Yáñez-López
- Department of Radiology & Imagenology, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico;
| | - Georgina Victoria-Acosta
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Adolfo López-Ornelas
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Patricia García Alonso-Themann
- National Institute of Perinatology, Calle Montes Urales 800, Lomas - Virreyes, Lomas de Chapultepec IV Section, Miguel Hidalgo, Mexico City 11000, Mexico; (J.P.-D.); (P.G.A.-T.)
| | - José Moreno
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
| | - Carmen Palacios-Reyes
- Direction and Division of Research, Hospital Juárez de México, Av. Instituto Politécnico Nacional 5160, Magdalena de las Salinas, Gustavo A. Madero, Mexico City 07760, Mexico; (R.G.-A.); (J.B.-D.); (G.V.-A.); (A.L.-O.); (J.M.)
- Correspondence:
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20
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Mamedova E, Dimitrova D, Przhiyalkovskaya E, Buryakina S, Vasilyev E, Tiulpakov A, Belaya Z. Non-lethal Raine Syndrome in a Middle-Aged Woman Caused by a Novel FAM20C Mutation. Calcif Tissue Int 2019; 105:567-572. [PMID: 31471673 DOI: 10.1007/s00223-019-00599-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/16/2019] [Indexed: 12/21/2022]
Abstract
Raine syndrome is a rare hereditary disease caused by mutations in the FAM20C gene. Only 18 non-lethal cases have been reported, the majority of them being children and young adults aged up to 30. Due to the rarity of the disease, genotype-phenotype correlations are not available and patient life expectancy is unknown, thus making descriptions of each novel case of particular importance. In this article, we describe a case of an Armenian woman, living in Russia, who was followed-up from age 36 to 39, presenting with pain in the extremities, osteosclerosis with periosteal bone formation, multiple calcifications in solid organs, midface hypoplasia, exophthalmos, amelogenesis imperfecta, shortening of distal phalanges, pectus excavatum, and hypophosphatemia due to renal phosphate wasting. Whole exome sequencing was performed on NextSeq 550 (Illumina, USA) and compound heterozygous variants were identified in the FAM20C gene (reference sequence NM_020223): a frameshift insertion c.1107_1108insTACTG (p.Tyr369fs) and a missense substitution c.1375C > G (p.Arg459Gly). This is the first reported case of a middle-aged patient presenting classical symptoms of Raine syndrome caused by novel compound heterozygous mutations in the conserved C-terminal domain of FAM20C gene.
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Affiliation(s)
- Elizaveta Mamedova
- Department of Neuroendocrinology and Bone Diseases, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation.
| | - Diana Dimitrova
- Department of Neuroendocrinology and Bone Diseases, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
| | - Elena Przhiyalkovskaya
- Department of Neuroendocrinology and Bone Diseases, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
| | - Svetlana Buryakina
- Department of Radiology, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
| | - Evgeny Vasilyev
- Department and Laboratory of Inherited Endocrine Disorders, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
| | - Anatoly Tiulpakov
- Department and Laboratory of Inherited Endocrine Disorders, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
| | - Zhanna Belaya
- Department of Neuroendocrinology and Bone Diseases, Endocrinology Research Centre, Ulitsa Dmitriya Ulianova, 11, Moscow, 117036, Russian Federation
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21
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Hung CY, Rodriguez M, Roberts A, Bauer M, Mihalek I, Bodamer O. A novel FAM20C mutation causes a rare form of neonatal lethal Raine syndrome. Am J Med Genet A 2019; 179:1866-1871. [PMID: 31297960 DOI: 10.1002/ajmg.a.61291] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 05/08/2019] [Accepted: 06/23/2019] [Indexed: 02/06/2023]
Abstract
Raine syndrome is a rare, autosomal recessive, osteosclerotic bone dysplasia due to pathogenic variants in FAM20C. The clinical phenotype is characterized by generalized osteosclerosis affecting all bones, cerebral calcifications, and craniofacial dysmorphism. Most cases present during the neonatal period with early lethality due to pulmonary hypoplasia and respiratory compromise while only few affected individuals have been reported to survive into adulthood. FAM20C is a ubiquitously expressed protein kinase that contains five functional domains including a catalytic domain, a binding pocket for FAM20A and three distinct N-glycosylation sites. We report a newborn infant with a history of prenatal onset fractures, generalized osteosclerosis, and craniofacial dysmorphism and early lethality. The clinical presentation was highly suggestive of Raine syndrome. A homozygous, novel missense variant in exon 5 of FAM20C (c.1007T>G; p.Met336Arg) was identified by targeted Sanger sequencing. Following in silico analysis and mapping of the variant on a three-dimensional (3D) model of FAM20C it is predicted to be deleterious and to affect N-glycosylation, protein folding, and subsequent secretion of FAM20C. In addition, we reviewed all published FAM20C mutations and observed that most pathogenic variants affect functional regions within the protein establishing evidence for an emerging genotype-phenotype correlation.
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Affiliation(s)
- Christina Y Hung
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Mario Rodriguez
- Hussmann Institute of Genomics, University of Miami, Miami, Florida
| | - Abra Roberts
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
| | - Mislen Bauer
- Division of Clinical Genetics and Metabolism, Nicklas Children's Hospital, Miami, Florida
| | - Ivana Mihalek
- Department of Molecular Medicine and Biotechnology, University of Rijeka, Rijeka, Croatia
| | - Olaf Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts
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22
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Laugel-Haushalter V, Bär S, Schaefer E, Stoetzel C, Geoffroy V, Alembik Y, Kharouf N, Huckert M, Hamm P, Hemmerlé J, Manière MC, Friant S, Dollfus H, Bloch-Zupan A. A New SLC10A7 Homozygous Missense Mutation Responsible for a Milder Phenotype of Skeletal Dysplasia With Amelogenesis Imperfecta. Front Genet 2019; 10:504. [PMID: 31191616 PMCID: PMC6546871 DOI: 10.3389/fgene.2019.00504] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 05/07/2019] [Indexed: 01/25/2023] Open
Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of rare inherited diseases presenting with enamel defects. More than 30 genes have been reported to be involved in syndromic or non-syndromic AI and new genes are continuously discovered (Smith et al., 2017). Whole-exome sequencing was performed in a consanguineous family. The affected daughter presented with intra-uterine and postnatal growth retardation, skeletal dysplasia, macrocephaly, blue sclerae, and hypoplastic AI. We identified a homozygous missense mutation in exon 11 of SLC10A7 (NM_001300842.2: c.908C>T; p.Pro303Leu) segregating with the disease phenotype. We found that Slc10a7 transcripts were expressed in the epithelium of the developing mouse tooth, bones undergoing ossification, and in vertebrae. Our results revealed that SLC10A7 is overexpressed in patient fibroblasts. Patient cells display altered intracellular calcium localization suggesting that SLC10A7 regulates calcium trafficking. Mutations in this gene were previously reported to cause a similar syndromic phenotype, but with more severe skeletal defects (Ashikov et al., 2018;Dubail et al., 2018). Therefore, phenotypes resulting from a mutation in SLC10A7 can vary in severity. However, AI is the key feature indicative of SLC10A7 mutations in patients with skeletal dysplasia. Identifying this important phenotype will improve clinical diagnosis and patient management.
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Affiliation(s)
- Virginie Laugel-Haushalter
- Laboratoire de Génétique Médicale, UMR_S INSERM U1112, Faculté de Médecine, FMTS, Institut Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Strasbourg, France
| | - Séverine Bär
- Laboratoire de Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Laboratoire de Génétique Médicale, UMR_S INSERM U1112, Faculté de Médecine, FMTS, Institut Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, IGMA, Strasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, UMR_S INSERM U1112, Faculté de Médecine, FMTS, Institut Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Strasbourg, France
| | - Véronique Geoffroy
- Laboratoire de Génétique Médicale, UMR_S INSERM U1112, Faculté de Médecine, FMTS, Institut Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Strasbourg, France
| | - Yves Alembik
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, IGMA, Strasbourg, France
| | - Naji Kharouf
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.,Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Strasbourg, France
| | - Mathilde Huckert
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Pauline Hamm
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France
| | - Joseph Hemmerlé
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.,Laboratoire de Biomatériaux et Bioingénierie, Inserm UMR_S 1121, Strasbourg, France
| | - Marie-Cécile Manière
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.,Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filière Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France
| | - Sylvie Friant
- Laboratoire de Génétique Moléculaire, Génomique, Microbiologie (GMGM), UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, UMR_S INSERM U1112, Faculté de Médecine, FMTS, Institut Génétique Médicale d'Alsace (IGMA), Université de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, IGMA, Strasbourg, France.,Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Agnès Bloch-Zupan
- Faculté de Chirurgie Dentaire, Université de Strasbourg, Strasbourg, France.,Pôle de Médecine et Chirurgie Bucco-dentaires, Hôpital Civil, Centre de référence des maladies rares orales et dentaires, O-Rares, Filière Santé Maladies rares TETE COU, European Reference Network ERN CRANIO, Hôpitaux Universitaires de Strasbourg (HUS), Strasbourg, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM U1258, CNRS-UMR7104, Université de Strasbourg, Illkirch-Graffenstaden, France.,Eastman Dental Institute, University College London, London, United Kingdom
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23
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Wang YP, Lin HY, Zhong WL, Simmer JP, Wang SK. Transcriptome analysis of gingival tissues of enamel-renal syndrome. J Periodontal Res 2019; 54:653-661. [PMID: 31131889 DOI: 10.1111/jre.12666] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 04/08/2019] [Accepted: 04/12/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND AND OBJECTIVE Biallelic loss-of-function mutations of human FAM20A have been known to cause enamel-renal syndrome (ERS), featured by agenesis of dental enamel, nephrocalcinosis, and other orodental abnormalities, including gingival hyperplasia. However, while the histopathology of this gingival anomaly has been analyzed, its underlying molecular mechanism remains largely unknown. This study aimed to unravel the pathogenesis of gingival hyperplasia in ERS. METHODS Whole-exome sequencing was conducted for an ERS case. Transcriptome analyses, using RNA sequencing, of the patient's gingiva were performed to unravel dysregulated molecules and aberrant biological processes underlying the gingival pathology of ERS, which was further confirmed by histology and immunohistochemistry. RESULTS Two novel frameshift FAM20A mutations in Exon 1 (g.5417delG; c.129delG; p.Cys44Alafs*101) and Exon 5 (g.62248_62249delAG; c.734_735delAG; p.Glu245Glyfs*11) were identified. Transcriptional profiling of patient's gingival tissue revealed a total of 1683 genes whose expression had increased (1129 genes) or decreased (554 genes) at least 2-fold compared to control gingival tissues. There were 951 gene ontology (GO) terms of biological process being significantly over-represented or under-represented. While GOs involved in extracellular matrix organization, angiogenesis, biomineralization, and epithelial cell proliferation appeared to be activated in ERS gingiva, genes related to keratinocyte differentiation, epithelial development, and keratinization were of decreased expression. FAM20A immunohistochemistry revealed a strong reactivity at the suprabasal layers of epithelium in control gingiva but showed a significantly diminished and scattered signal in ERS tissues. For genes showing significant over-expression in the transcriptome analyses, namely ALPL, SPARC, and ACTA2, an increased immunoreactivity was observed. CONCLUSION Our results unraveled a potential role for FAM20A in homeostasis of both gingival epithelium and connective tissues.
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Affiliation(s)
- Yi-Ping Wang
- Department of Dentistry, School of Dentistry, National Taiwan University, Taipei City, Taiwan.,Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei City, Taiwan
| | - Hung-Ying Lin
- Department of Oral and Maxillofacial Surgery, National Taiwan University Hospital, Taipei City, Taiwan
| | - Wen-Lan Zhong
- Department of Dentistry, School of Dentistry, National Taiwan University, Taipei City, Taiwan
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of Dentistry, Ann Arbor, Michigan
| | - Shih-Kai Wang
- Department of Dentistry, School of Dentistry, National Taiwan University, Taipei City, Taiwan.,Department of Pediatric Dentistry, National Taiwan University Children's Hospital, Taipei City, Taiwan
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24
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Rolvien T, Kornak U, Schinke T, Amling M, Oheim R. A novel FAM20C mutation causing hypophosphatemic osteomalacia with osteosclerosis (mild Raine syndrome) in an elderly man with spontaneous osteonecrosis of the knee. Osteoporos Int 2019; 30:685-689. [PMID: 30151622 DOI: 10.1007/s00198-018-4667-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 08/12/2018] [Indexed: 12/11/2022]
Abstract
Raine syndrome is characterized by FGF23-mediated hypophosphatemic osteomalacia with osteosclerosis caused by mutations in the FAM20C gene. We report a case of a 72-year-old man who presented with rapid progressive spontaneous osteonecrosis of the knee (SONK). A full osteologic assessment including dual energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and serum analyses revealed a high bone mass in the lumbar spine and hip (DXA T-score + 7.5 and + 4.7/+4.2) with increased bone microstructural parameters in the distal radius and tibia (BV/TV 127%, 140% of the age-matched mean, respectively), as well as a low bone turnover state. Phosphate levels were low due to renal phosphate wasting and high FGF23 levels (126.5 pg/ml, reference range 23.2-95.4 pg/ml). Using gene panel sequencing, we identified a novel FAM20C heterozygous missense mutation in combination with a homozygous duplication that potentially alters splicing. Taken together, this is the first case of mild Raine syndrome with spontaneous osteonecrosis of the knee, phosphate wasting, and a pronounced trabecular high bone mass phenotype.
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Affiliation(s)
- T Rolvien
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- Department of Orthopedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- National Bone Board, Martin Zeitz Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - U Kornak
- National Bone Board, Martin Zeitz Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin-Brandenburg School for Regenerative Therapies, Charité-Universitätsmedizin Berlin, Berlin, Germany
- FG Development and Disease, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - T Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- National Bone Board, Martin Zeitz Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - M Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany
- National Bone Board, Martin Zeitz Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - R Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Lottestr. 59, 22529, Hamburg, Germany.
- National Bone Board, Martin Zeitz Center for Rare Diseases, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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25
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Abstract
The group of sclerosing bone dysplasia's is a clinically and genetically heterogeneous group of rare bone disorders which, according to the latest Nosology and classification of genetic skeletal disorders (2015), can be subdivided in three subgroups; the neonatal osteosclerotic dysplasias, the osteopetroses and related disorders and the other sclerosing bone disorders. Here, we give an overview of the most important radiographic and clinical symptoms, the underlying genetic defect and potential treatment options of the different sclerosing dysplasias included in these subgroups.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
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26
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A three-generation family with metaphyseal dysplasia, maxillary hypoplasia and brachydactyly (MDMHB) due to intragenic RUNX2 duplication. Eur J Hum Genet 2018; 26:1288-1293. [PMID: 29891876 DOI: 10.1038/s41431-018-0166-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 03/29/2018] [Accepted: 04/11/2018] [Indexed: 12/22/2022] Open
Abstract
Metaphyseal dysplasia with maxillary hypoplasia and brachydactyly (MDMHB) is an autosomal-dominant skeletal dysplasia characterised by metaphyseal flaring of the long bones, enlargement of the medial halves of the clavicles, maxillary hypoplasia, brachydactyly, dental anomalies and mild osteoporosis. To date, only one large French Canadian family and a Finnish woman have been reported with the condition. In both, intragenic duplication encompassing exons 3-5 of the RUNX2 gene was identified. We describe a new, three-generation family with clinical features of MDMHB and an intragenic tandem duplication of RUNX2 exons 3-6. Dental problems were the primary presenting feature in all four affected individuals. We compare the features in our family to those previously reported in MDMHB, review the natural history of this condition and highlight the importance of considering an underlying skeletal dysplasia in patients presenting with significant dental problems and other suggestive features, including disproportionate short stature and/or digital anomalies.
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27
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Sheth J, Bhavsar R, Gandhi A, Sheth F, Pancholi D. A case of Raine syndrome presenting with facial dysmorphy and review of literature. BMC MEDICAL GENETICS 2018; 19:76. [PMID: 29751744 PMCID: PMC5948820 DOI: 10.1186/s12881-018-0593-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 04/25/2018] [Indexed: 11/29/2022]
Abstract
Background Raine syndrome (RS) – an extremely rare autosomal recessive genetic disorder, is caused by a biallelic mutation in the FAM20C gene. Some of the most common clinical features include generalized osteosclerosis with a periosteal bone formation, dysmorphic face, and thoracic hypoplasia. Many cases have also been reported with oro-dental abnormalities, and developmental delay. Most of the cases result in neonatal death. However, a few non-lethal RS cases have been reported where patients survive till adulthood and exhibits a heterogeneous clinical phenotype. Clinical diagnosis of RS has been done through facial appearance and radiological findings, while confirmatory diagnosis has been conducted through a molecular study of the FAM20C gene. Case presentation A 6-year-old girl was born to healthy third degree consanguineous parents. She presented with facial dysmorphy, delayed speech, and delayed cognition. Radiography showed small sclerotic areas in the lower part of the right femur, and an abnormally-shaped skull with minimal sclerosis in the lower occipital region. Computer tomography scan of the brain revealed mild cortical atrophy, and MRI scan of the brain showed corpus callosal dysgenesis with the absence of the rostral area. Chromosome banding at 500 band resolution showed a normal female karyotype. No quantitative genomic imbalance was detected by aCGH. Further study conducted using Clinical Exome Sequencing identified a homozygous missense variation c.1228 T > A (p.Ser410Thr) in the exon 6 of FAM20C gene – a likely pathogenic variant that confirmed the clinical diagnosis of RS. The variant was confirmed in the proband and her parents using Sanger sequencing. Prenatal diagnosis during subsequent pregnancy revealed heterozygous status of the fetus, and a normal carrier child was delivered at term. Conclusions The syndrome revealed markedly variable presentations such as facial dysmorphy and developmental delay, and was localized to diffuse bone osteosclerosis. Clinical indications, striking radiological findings and molecular testing of FAM20C gene confirmed the diagnosis of RS. A rarity of the disorder and inconsistent phenotype hindered the establishment of genotype-phenotype correlations in RS. Therefore, reporting more cases and conducting further research would be crucial in defining the variable radiologic and molecular defects of the lethal and non-lethal forms of this syndrome. Electronic supplementary material The online version of this article (10.1186/s12881-018-0593-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jayesh Sheth
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380015, India.
| | - Riddhi Bhavsar
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380015, India
| | - Ajit Gandhi
- Unique Hospital, Main Road, South Kasba, Solapur, 413007, India
| | - Frenny Sheth
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380015, India
| | - Dhairya Pancholi
- FRIGE's Institute of Human Genetics, FRIGE House, Jodhpur Gam Road, Satellite, Ahmedabad, 380015, India
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28
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Tamai K, Tada K, Takeuchi A, Nakamura M, Marunaka H, Washio Y, Tanaka H, Miya F, Okamoto N, Kageyama M. Fetal ultrasonographic findings including cerebral hyperechogenicity in a patient with non-lethal form of Raine syndrome. Am J Med Genet A 2018; 176:682-686. [PMID: 29341424 DOI: 10.1002/ajmg.a.38598] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/05/2017] [Accepted: 12/12/2017] [Indexed: 12/14/2022]
Abstract
Raine syndrome is a rare osteosclerotic bone dysplasia characterized by craniofacial anomalies and intracranial calcification. Most patients with Raine syndrome are of Arab ancestry and die during the neonatal period. We herein report a Japanese patient with non-lethal Raine syndrome who presented with characteristic cerebral hyperechogenicity and a hypoplastic nose by fetal ultrasonography. She was admitted to the NICU due to pyriform aperture stenosis. Craniofacial abnormalities, intracranial calcification, osteosclerosis, chondrodysplasia punctata, and a mutation of FAM20C was identified. She was subsequently discharged without surgical intervention and is now 2 years old with mild neurodevelopmental delays. Images of cerebral hyperechogenicity by fetal ultrasonography in a non-lethal case were described herein for the first time. This patient represents a rare occurrence of a child with Raine syndrome born to Japanese parents and confirms that this syndrome is not always lethal. Even if Raine syndrome is suspected in a fetus due to cerebral hyperechogenicity and a hypoplastic nose, cerebral hyperechogenicity without pulmonary hypoplasia does not always predict lethality or severe neurodevelopmental delays. The information provided herein will be useful for prenatal counseling.
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Affiliation(s)
- Kei Tamai
- Department of Neonatology, NHO Okayama Medical Center, Okayama, Japan
| | - Katsuhiko Tada
- Department of Obstetrics and Gynecology, NHO Okayama Medical Center, Okayama, Japan
| | - Akihito Takeuchi
- Department of Neonatology, NHO Okayama Medical Center, Okayama, Japan
| | - Makoto Nakamura
- Department of Neonatology, NHO Okayama Medical Center, Okayama, Japan
| | - Hidenori Marunaka
- Department of Otolaryngology, NHO Okayama Medical Center, Okayama, Japan
| | - Yosuke Washio
- Department of Pediatrics, Okayama University Hospital, Okayama, Japan
| | - Hiroyuki Tanaka
- Department of Pediatrics, Okayama Saiseikai General Hospital, Okayama, Japan
| | - Fuyuki Miya
- Department of Medical Science Mathematics, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.,Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Women's and Children's Hospital, Osaka, Japan
| | - Misao Kageyama
- Department of Neonatology, NHO Okayama Medical Center, Okayama, Japan
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29
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Boudin E, Van Hul W. MECHANISMS IN ENDOCRINOLOGY: Genetics of human bone formation. Eur J Endocrinol 2017; 177:R69-R83. [PMID: 28381451 DOI: 10.1530/eje-16-0990] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/15/2017] [Accepted: 04/05/2017] [Indexed: 12/21/2022]
Abstract
Throughout life, bone is continuously remodelled to be able to fulfil its multiple functions. The importance of strictly regulating the bone remodelling process, which is defined by the sequential actions of osteoclasts and osteoblasts, is shown by a variety of disorders with abnormalities in bone mass and strength. The best known and most common example of such a disorder is osteoporosis, which is marked by a decreased bone mass and strength that consequently results in an increased fracture risk. As osteoporosis is a serious health problem, a large number of studies focus on elucidating the aetiology of the disease as well as on the identification of novel therapeutic targets for the treatment of osteoporotic patients. These studies have demonstrated that a large amount of variation in bone mass and strength is often influenced by genetic variation in genes encoding important regulators of bone homeostasis. Throughout the years, studies into the genetic causes of osteoporosis as well as several rare monogenic disorders with abnormal high or low bone mass and strength have largely increased the knowledge on regulatory pathways important for bone resorption and formation. This review gives an overview of genes and pathways that are important for the regulation of bone formation and that are identified through their involvement in monogenic and complex disorders with abnormal bone mass. Furthermore, novel bone-forming strategies for the treatment of osteoporosis that resulted from these discoveries, such as antibodies against sclerostin, are discussed as well.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp, Antwerp, Belgium
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30
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Lignon G, Beres F, Quentric M, Rouzière S, Weil R, De La Dure-Molla M, Naveau A, Kozyraki R, Dessombz A, Berdal A. FAM20A Gene Mutation: Amelogenesis or Ectopic Mineralization? Front Physiol 2017; 8:267. [PMID: 28515694 PMCID: PMC5413562 DOI: 10.3389/fphys.2017.00267] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 04/11/2017] [Indexed: 12/12/2022] Open
Abstract
Background and objective:FAM20A gene mutations result in enamel renal syndrome (ERS) associated with amelogenesis imperfecta (AI), nephrocalcinosis, gingival fibromatosis, and impaired tooth eruption. FAM20A would control the phosphorylation of enamel peptides and thus enamel mineralization. Here, we characterized the structure and chemical composition of unerupted tooth enamel from ERS patients and healthy subjects. Methods: Tooth sections were analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF). Results: SEM revealed that prisms were restricted to the inner-most enamel zones. The bulk of the mineralized matter covering the crown was formed by layers with varying electron-densities organized into lamellae and micronodules. Tissue porosity progressively increased at the periphery, ending with loose and unfused nanonodules also observed in the adjoining soft tissues. Thus, the enamel layer covering the dentin in all ERS patients (except a limited layer of enamel at the dentino-enamel junction) displayed an ultrastructural globular pattern similar to one observed in ectopic mineralization of soft tissue, notably in the gingiva of Fam20a knockout mice. XRD analysis confirmed the existence of alterations in crystallinity and composition (vs. sound enamel). XRF identified lower levels of calcium and phosphorus in ERS enamel. Finally, EDS confirmed the reduced amount of calcium in ERS enamel, which appeared similar to dentin. Conclusion: This study suggests that, after an initial normal start to amelogenesis, the bulk of the tissue covering coronal dentin would be formed by different mechanisms based on nano- to micro-nodule aggregation. This evocated ectopic mineralization process is known to intervene in several soft tissues in FAM20A gene mutant.
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Affiliation(s)
- Guilhem Lignon
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Fleur Beres
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Mickael Quentric
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Stephan Rouzière
- Laboratoire de Physique des Solides, Centre National de la Recherche Scientifique, Univ. Paris-Sud, Université Paris-SaclayOrsay Cedex, France
| | - Raphael Weil
- Laboratoire de Physique des Solides, Centre National de la Recherche Scientifique, Univ. Paris-Sud, Université Paris-SaclayOrsay Cedex, France
| | - Muriel De La Dure-Molla
- Reference Center of Rare Buccal and Facial Malformations MAFACE-Rothschild Hospital, APHPParis, France
| | - Adrien Naveau
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Renata Kozyraki
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Arnaud Dessombz
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France
| | - Ariane Berdal
- Molecular Oral Pathophysiology, Cordeliers Research Center, UMRS 1138 Institut National de la Santé et de la Recherche Médicale, Paris-Descartes, Pierre-et-Marie-Curie, Paris-Diderot UniversitiesParis, France.,Reference Center of Rare Buccal and Facial Malformations MAFACE-Rothschild Hospital, APHPParis, France
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31
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Cui J, Zhu Q, Zhang H, Cianfrocco MA, Leschziner AE, Dixon JE, Xiao J. Structure of Fam20A reveals a pseudokinase featuring a unique disulfide pattern and inverted ATP-binding. eLife 2017; 6. [PMID: 28432788 PMCID: PMC5413348 DOI: 10.7554/elife.23990] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/20/2017] [Indexed: 12/19/2022] Open
Abstract
Mutations in FAM20A cause tooth enamel defects known as Amelogenesis Imperfecta (AI) and renal calcification. We previously showed that Fam20A is a secretory pathway pseudokinase and allosterically activates the physiological casein kinase Fam20C to phosphorylate secreted proteins important for biomineralization (Cui et al., 2015). Here we report the nucleotide-free and ATP-bound structures of Fam20A. Fam20A exhibits a distinct disulfide bond pattern mediated by a unique insertion region. Loss of this insertion due to abnormal mRNA splicing interferes with the structure and function of Fam20A, resulting in AI. Fam20A binds ATP in the absence of divalent cations, and strikingly, ATP is bound in an inverted orientation compared to other kinases. Fam20A forms a dimer in the crystal, and residues in the dimer interface are critical for Fam20C activation. Together, these results provide structural insights into the function of Fam20A and shed light on the mechanism by which Fam20A mutations cause disease. DOI:http://dx.doi.org/10.7554/eLife.23990.001
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Affiliation(s)
- Jixin Cui
- Department of Pharmacology, University of California, San Diego, United States
| | - Qinyu Zhu
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,The State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Hui Zhang
- Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, China.,The State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Michael A Cianfrocco
- Department of Cellular and Molecular Medicine, University of California, San Diego, United States
| | - Andres E Leschziner
- Department of Cellular and Molecular Medicine, University of California, San Diego, United States
| | - Jack E Dixon
- Department of Pharmacology, University of California, San Diego, United States.,Department of Cellular and Molecular Medicine, University of California, San Diego, United States.,Department of Chemistry and Biochemistry, University of California, San Diego, United States
| | - Junyu Xiao
- The State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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