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Ivanova NG. A Sole Case of the FGF23 Gene Mutation c.202A>G (p.Thr68Ala) Associated with Multiple Severe Vascular Aneurysms and a Hyperphosphatemic Variant of Tumoral Calcinosis-A Case Report. Life (Basel) 2024; 14:613. [PMID: 38792634 PMCID: PMC11123361 DOI: 10.3390/life14050613] [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: 04/07/2024] [Revised: 05/02/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
Tumoral calcinosis is an extremely rare genetic disease caused by mutations in three genes, GALNT3, FGF23, and KL, which disrupt phosphorus metabolism. The hallmark of this condition is the formation of tumors in the soft tissues around the joints. Other phenotypic features of tumoral calcinosis are dental involvement and brain and vascular calcifications. The clinical case reported herein presents for the first time to the scientific community the c.202A>G (p.Thr68Ala) mutation of the FGF23 gene, associated with a hyperphosphatemic variant of tumoral calcinosis and multiple severe vascular aneurysms. A female patient underwent multiple surgeries for tumor formations in her soft tissues that first appeared at the age of 12 months. On this occurrence, the patient was found to have hyperphosphatemia, low phosphate clearance, increased tubular reabsorption with normal levels of total and ionized calcium, vitamin D3, and parathyroid hormone, and no effect of treatment with sevelamer hydrochloride and a low-phosphate diet. At the age of 39, the patient underwent imaging studies due to edema and a pulsating formation in the neck area, which revealed multiple vascular aneurysms with thrombosis, for which she received operative and interventional treatment. In this connection, and because of the established phosphorus metabolism disturbance, a genetic disease was suspected. The sequence analysis and deletion/duplication testing of the 358 genes performed on this occasion revealed that the woman was homozygous for a variant of the c.202A>G (p.Thr68Ala) mutation of the FGF23 gene. The established mutation is not present in population databases. The presented clinical case is the first and only one in the world to demonstrate the role of this type of FGF23 gene mutation in the development of a hyperphosphatemic variant of tumoral calcinosis characterized by aggressive formation of multiple vascular aneurysms.
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Affiliation(s)
- Nevena Georgieva Ivanova
- Department of Urology and General Medicine, Faculty of Medicine, Medical University of Plovdiv, 4000 Plovdiv, Bulgaria; ; Tel.: +35-98-8913-0416
- St Karidad MHAT, Karidad Medical Health Center, 4004 Plovdiv, Bulgaria
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2
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Sowaity ZA, Saleem JY, Sabooh TN, Dukmak ON, Abu Al-Saoud SY. Three Siblings With a Rare Familial Hyperphosphatemia Syndrome: A Case Series. Cureus 2024; 16:e55575. [PMID: 38576700 PMCID: PMC10994165 DOI: 10.7759/cureus.55575] [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] [Accepted: 03/05/2024] [Indexed: 04/06/2024] Open
Abstract
Hyperphosphatemia familial tumoral calcinosis (HFTC) and hyperphosphatemia hyperostosis syndrome (HHS) are rare autosomal recessive disorders caused by mutations in the polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3), fibroblast growth factor 23 (FGF23), or klotho (KL) genes. They are characterized by hyperphosphatemia and recurrent episodes of bone lesions with hyperostosis and/or soft tissue calcinosis. Management options include phosphate-lowering therapies, anti-inflammatory medications, and surgical excision of the calcified masses in significantly disabled cases. We describe three cases from a consanguineous family who were found to have the same genetic mutation caused by a homozygous mutation in intron eight of GALNT3 c.1524+1 G>A (IVS8+1). The first case had a presentation similar to chronic osteomyelitis, while the second one presented with a calcified mass in her gluteal area. The third case presented with left leg pain. Being a rare disease, the findings of tumoral calcinosis/ bony abnormalities, along with elevated phosphate levels, should raise the possibility of this entity. Family history and biochemical findings can help reach the diagnosis.
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Affiliation(s)
| | | | | | | | - Sima Y Abu Al-Saoud
- Department of Pediatrics, Makassed Hospital, Al-Quds University, Jerusalem, PSE
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3
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Hassan N, Gregson CL, Tang H, van der Kamp M, Leo P, McInerney‐Leo AM, Zheng J, Brandi ML, Tang JCY, Fraser W, Stone MD, Grundberg E, Brown MA, Duncan EL, Tobias JH. Rare and Common Variants in GALNT3 May Affect Bone Mass Independently of Phosphate Metabolism. J Bone Miner Res 2023; 38:678-691. [PMID: 36824040 PMCID: PMC10729283 DOI: 10.1002/jbmr.4795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/15/2023] [Accepted: 02/22/2023] [Indexed: 02/25/2023]
Abstract
Anabolic treatment options for osteoporosis remain limited. One approach to discovering novel anabolic drug targets is to identify genetic causes of extreme high bone mass (HBM). We investigated a pedigree with unexplained HBM within the UK HBM study, a national cohort of probands with HBM and their relatives. Whole exome sequencing (WES) in a family with HBM identified a rare heterozygous missense variant (NM_004482.4:c.1657C > T, p.Arg553Trp) in GALNT3, segregating appropriately. Interrogation of data from the UK HBM study and the Anglo-Australasian Osteoporosis Genetics Consortium (AOGC) revealed an unrelated individual with HBM with another rare heterozygous variant (NM_004482.4:c.831 T > A, p.Asp277Glu) within the same gene. In silico protein modeling predicted that p.Arg553Trp would disrupt salt-bridge interactions, causing instability of GALNT3, and that p.Asp277Glu would disrupt manganese binding and consequently GALNT3 catalytic function. Bi-allelic loss-of-function GALNT3 mutations alter FGF23 metabolism, resulting in hyperphosphatemia and causing familial tumoral calcinosis (FTC). However, bone mineral density (BMD) in FTC cases, when reported, has been either normal or low. Common variants in the GALNT3 locus show genome-wide significant associations with lumbar, femoral neck, and total body BMD. However, no significant associations with BMD are observed at loci coding for FGF23, its receptor FGFR1, or coreceptor klotho. Mendelian randomization analysis, using expression quantitative trait loci (eQTL) data from primary human osteoblasts and genome-wide association studies data from UK Biobank, suggested increased expression of GALNT3 reduces total body, lumbar spine, and femoral neck BMD but has no effect on phosphate concentrations. In conclusion, rare heterozygous loss-of-function variants in GALNT3 may cause HBM without altering phosphate concentration. These findings suggest that GALNT3 may affect BMD through pathways other than FGF23 regulation, the identification of which may yield novel anabolic drug targets for osteoporosis. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Neelam Hassan
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Celia L. Gregson
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | - Haotian Tang
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
| | | | - Paul Leo
- Faculty of Health, Translational Genomics Group, Institute of Health and Biomedical InnovationQueensland University of TechnologyBrisbaneQueenslandAustralia
| | - Aideen M. McInerney‐Leo
- The Faculty of Medicine, Frazer InstituteThe University of QueenslandWoolloongabbaQueenslandAustralia
| | - Jie Zheng
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- Department of Endocrine and Metabolic Diseases, Shanghai Institute of Endocrine and Metabolic Diseases, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai National Clinical Research Center for metabolic Diseases, Key Laboratory for Endocrine and Metabolic Diseases of the National Health Commission of the PR ChinaShanghai Jiao Tong University School of MedicineShanghaiChina
- Shanghai Key Laboratory for Endocrine Tumor, State Key Laboratory of Medical Genomics, Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghaiChina
| | | | - Jonathan C. Y. Tang
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Clinical Biochemistry, Departments of Laboratory MedicineNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - William Fraser
- Norwich Medical SchoolUniversity of East AngliaNorwichUK
- Department of Diabetes, Endocrinology and Clinical BiochemistryNorfolk and Norwich University Hospital NHS Foundation TrustNorwichUK
| | - Michael D. Stone
- University Hospital LlandoughCardiff & Vale University Health BoardCardiffUK
| | - Elin Grundberg
- Genomic Medicine CenterChildren's Mercy Kansas CityKansas CityMissouriUSA
| | | | | | - Emma L. Duncan
- Department of Twin Research and Genetic Epidemiology, School of Life Course & Population Sciences, Faculty of Life Sciences and MedicineKing's College LondonLondonUK
| | - Jonathan H. Tobias
- Musculoskeletal Research Unit, Translational Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
- MRC Integrated Epidemiology Unit, Population Health Sciences, Bristol Medical SchoolUniversity of BristolBristolUK
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Aslan B, Varlı B, Öztürk Ç, Ortaç UF. A case of tumoral calcinosis in anterior vaginal wall. J OBSTET GYNAECOL 2021; 42:535-536. [PMID: 34558379 DOI: 10.1080/01443615.2021.1952169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Batuhan Aslan
- Department of Obstetrics and Gynecology, Ankara University School of Medicine, Ankara, Turkey
| | - Bulut Varlı
- Department of Obstetrics and Gynecology, Ankara University School of Medicine, Ankara, Turkey
| | - Çağatayhan Öztürk
- Department of Obstetrics and Gynecology, Ankara University School of Medicine, Ankara, Turkey
| | - Uğur Fırat Ortaç
- Department of Obstetrics and Gynecology, Ankara University School of Medicine, Ankara, Turkey
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5
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Kato K, Hansen L, Clausen H. Polypeptide N-acetylgalactosaminyltransferase-Associated Phenotypes in Mammals. Molecules 2021; 26:5504. [PMID: 34576978 PMCID: PMC8472655 DOI: 10.3390/molecules26185504] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/07/2021] [Accepted: 09/08/2021] [Indexed: 01/31/2023] Open
Abstract
Mucin-type O-glycosylation involves the attachment of glycans to an initial O-linked N-acetylgalactosamine (GalNAc) on serine and threonine residues on proteins. This process in mammals is initiated and regulated by a large family of 20 UDP-GalNAc: polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts) (EC 2.4.1.41). The enzymes are encoded by a large gene family (GALNTs). Two of these genes, GALNT2 and GALNT3, are known as monogenic autosomal recessive inherited disease genes with well characterized phenotypes, whereas a broad spectrum of phenotypes is associated with the remaining 18 genes. Until recently, the overlapping functionality of the 20 members of the enzyme family has hindered characterizing the specific biological roles of individual enzymes. However, recent evidence suggests that these enzymes do not have full functional redundancy and may serve specific purposes that are found in the different phenotypes described. Here, we summarize the current knowledge of GALNT and associated phenotypes.
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Affiliation(s)
- Kentaro Kato
- Department of Eco-Epidemiology, Institute of Tropical Medicine, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Lars Hansen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
| | - Henrik Clausen
- Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, Mærsk Building, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark;
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6
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Mahjoubi F, Ghadir M, Samanian S, Heydari I, Honardoost M. Hyperphosphatemic familial tumoral calcinosis caused by a novel variant in the GALNT3 gene. J Endocrinol Invest 2020; 43:1125-1130. [PMID: 32125652 DOI: 10.1007/s40618-020-01203-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 02/19/2020] [Indexed: 10/24/2022]
Abstract
AIM Hyperphosphatemic familial tumoral calcinosis (HFTC) is a rare endocrine disorder caused by autosomal recessive variants in GALNT3, FGF23, and KL leading to progressive calcification of soft tissues and subsequent clinical effects. The aim of this was to study the cause of HFTC in an Iranian family. PATIENTS AND METHODS Four generations of a family with HFTC were studied for understanding the genetic pattern of the disease. Whole exome sequencing was applied on genomic DNA of the proband. Based on its result, genetically altered sequences were checked in his family through sanger sequencing. Then bioinformatics approaches as well as co-segregation analysis were applied to validate the genetic alteration. RESULTS A novel homozygous variant in exon four of GALNT3, namely p.R261Q was found. The parents and sister were carriers. CONCLUSION To our knowledge, it is the first-reported Iranian family with GALNT3-CDG novel variant.
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Affiliation(s)
- F Mahjoubi
- Genetic Foundation of Tehran, Solaleh Diagnostic Laboratory, Tehran, Iran
- Department of Clinical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - M Ghadir
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, No 10, Firoozeh St, Vali-asr Sq, Tehran, Iran
| | - S Samanian
- Genetic Foundation of Tehran, Solaleh Diagnostic Laboratory, Tehran, Iran
| | - I Heydari
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, No 10, Firoozeh St, Vali-asr Sq, Tehran, Iran
| | - M Honardoost
- Endocrine Research Center, Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, No 10, Firoozeh St, Vali-asr Sq, Tehran, Iran.
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7
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Guerra MG, Videira T, de Fonseca D, Vieira R, Dos Santos J, Pinto S. Hyperphosphataemic familial tumoral calcinosis: case report of a rare and challenging disease. Scand J Rheumatol 2020; 49:80-81. [PMID: 31213107 DOI: 10.1080/03009742.2019.1602883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2019] [Indexed: 01/01/2023]
Affiliation(s)
- M G Guerra
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
| | - Tmfc Videira
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
| | - Dmgg de Fonseca
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
| | - Rcc Vieira
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
| | - Jpaa Dos Santos
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
| | - Spam Pinto
- Rheumatology Department, Vila Nova de Gaia/Espinho Hospital, Unit I, Vila Nova de Gaia, Portugal
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van Tol W, Wessels H, Lefeber DJ. O-glycosylation disorders pave the road for understanding the complex human O-glycosylation machinery. Curr Opin Struct Biol 2019; 56:107-118. [PMID: 30708323 DOI: 10.1016/j.sbi.2018.12.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 12/16/2018] [Accepted: 12/18/2018] [Indexed: 01/17/2023]
Abstract
Over 100 human Congenital Disorders of Glycosylation (CDG) have been described. Of these, about 30% reside in the O-glycosylation pathway. O-glycosylation disorders are characterized by a high phenotypic variability, reflecting the large diversity of O-glycan structures. In contrast to N-glycosylation disorders, a generic biochemical screening test is lacking, which limits the identification of novel O-glycosylation disorders. The emergence of next generation sequencing (NGS) and O-glycoproteomics technologies have changed this situation, resulting in significant progress to link disease phenotypes with underlying biochemical mechanisms. Here, we review the current knowledge on O-glycosylation disorders, and discuss the biochemical lessons that we can learn on 1) novel glycosyltransferases and metabolic pathways, 2) tissue-specific O-glycosylation mechanisms, 3) O-glycosylation targets and 4) structure-function relationships. Additionally, we provide an outlook on how genetic disorders, O-glycoproteomics and biochemical methods can be combined to answer fundamental questions regarding O-glycan synthesis, structure and function.
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Affiliation(s)
- Walinka van Tol
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hans Wessels
- Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Dirk J Lefeber
- Department of Neurology, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands; Translational Metabolic Laboratory, Department of Laboratory Medicine, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
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9
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Abstract
Our understanding of the regulation of phosphate balance has benefited tremendously from the molecular identification and characterization of genetic defects leading to a number of rare inherited or acquired disorders affecting phosphate homeostasis. The identification of the key phosphate-regulating hormone, fibroblast growth factor 23 (FGF23), as well as other molecules that control its production, such as the glycosyltransferase GALNT3, the endopeptidase PHEX, and the matrix protein DMP1, and molecules that function as downstream effectors of FGF23 such as the longevity factor Klotho and the phosphate transporters NPT2a and NPT2c, has permitted us to understand the complex interplay that exists between the kidneys, bone, parathyroid, and gut. Such insights from genetic disorders have allowed not only the design of potent targeted treatment of FGF23-dependent hypophosphatemic conditions, but also provide clinically relevant observations related to the dysregulation of mineral ion homeostasis in health and disease.
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Affiliation(s)
- Marta Christov
- Division of Nephrology, Department of Medicine, New York Medical College, Valhalla, NY, USA
| | - Harald Jüppner
- Endocrine Unit and Pediatric Nephrology Unit, Massachusetts General Hospital, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
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10
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Chakhtoura M, Ramnitz MS, Khoury N, Nemer G, Shabb N, Abchee A, Berberi A, Hourani M, Collins M, Ichikawa S, El Hajj Fuleihan G. Hyperphosphatemic familial tumoral calcinosis secondary to fibroblast growth factor 23 (FGF23) mutation: a report of two affected families and review of the literature. Osteoporos Int 2018; 29:1987-2009. [PMID: 29923062 DOI: 10.1007/s00198-018-4574-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/14/2018] [Indexed: 01/20/2023]
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC), secondary to fibroblast growth factor 23 (FGF23) gene mutation, is a rare genetic disorder characterized by recurrent calcified masses. We describe young Lebanese cousins presenting with HFTC, based on a retrospective chart review and a prospective case study. In addition, we present a comprehensive review on the topic, based on a literature search conducted in PubMed and Google Scholar, in 2014 and updated in December 2017. While the patients had the same previously reported FGF23 gene mutation (homozygous c.G367T variant in exon 3 leading to a missense mutation), they presented with variable severity and age of disease onset (at 4 years in patient 1 and at 23 years in patient 2). A review of the literature revealed several potential patho-physiologic pathways of HFTC clinical manifestations, some of which may be independent of hyperphosphatemia. Most available treatment options aim at reducing serum phosphate level, by stimulating renal excretion or by inhibiting intestinal absorption. HFTC is a challenging disease. While the available medical treatment has a limited and inconsistent effect on disease symptomatology, surgical resection of calcified masses remains the last resort. Research is needed to determine the safety and efficacy of FGF23 replacement or molecular therapy, targeting the specific genetic aberration. Hyperphosphatemic familial tumoral calcinosis is a rare genetic disorder characterized by recurrent calcified masses, in addition to other visceral, skeletal, and vascular manifestations. It remains a very challenging disease.
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Affiliation(s)
- M Chakhtoura
- Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon.
| | - M S Ramnitz
- Section on Skeletal Disorders and Mineral Homeostasis, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - N Khoury
- Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - G Nemer
- Department of Biochemistry and Molecular Genetics, American University of Beirut Medical Center, Beirut, Lebanon
| | - N Shabb
- Department of Pathology and Laboratory Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - A Abchee
- Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - A Berberi
- Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon
| | - M Hourani
- Department of Radiology, American University of Beirut Medical Center, Beirut, Lebanon
| | - M Collins
- Section on Skeletal Disorders and Mineral Homeostasis, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD, USA
| | - S Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - G El Hajj Fuleihan
- Calcium Metabolism and Osteoporosis Program, WHO Collaborating Center for Metabolic Bone Disorders, American University of Beirut Medical Center, Beirut, Lebanon
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11
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Added value of newer optical coherence tomography technologies in hyperphosphatemic familial tumoural calcinosis. Can J Ophthalmol 2018; 53:e8-e10. [PMID: 29426463 DOI: 10.1016/j.jcjo.2017.06.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 04/05/2017] [Accepted: 06/20/2017] [Indexed: 11/22/2022]
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12
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Jakka S, Narayan R, Mishra M, Rana F, Laik JK. Idiopathic Tumoral Calcinosis - Rare Clinico Pathological Entity: A Report of Two Cases. J Clin Diagn Res 2017; 11:ED06-ED07. [PMID: 28764177 DOI: 10.7860/jcdr/2017/26779.10070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 04/25/2017] [Indexed: 11/24/2022]
Abstract
Tumoral calcinosis is a rare disease reported mainly in blacks of tropical and subtropical African regions. It is characterized by tumour-like periarticular deposits of calcium that are found in the regions of the hip, shoulder, elbow and small joints of hands and feet. The involvement of this disease in a healthy patient is extremely rare in young and middle aged individuals. We are presenting two cases with large, painless periarticular swellings in subscapular joint and feet. First case presented with recurrent swelling in different anatomical locations at different time intervals involving the hip and followed by shoulder joint. Second case presented with swelling around the ankle joint. These two cases were diagnosed as Idiopathic tumoral calcinosis based on biochemical, radiological and histopathological findings.
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Affiliation(s)
- Sreedevi Jakka
- Specialist, Department of Pathology, Tata Main Hospital, Jamshedpur, Jharkhand, India
| | - Radhika Narayan
- Consultant, Department of Pathology, Tata Main Hospital, Jamshedpur, Jharkhand, India
| | - Minakshi Mishra
- Head Consultant, Department of Pathology, Tata Main Hospital, Jamshedpur, Jharkhand, India
| | - Farah Rana
- Specialist, Department of Pathology, Tata Main Hospital, Jamshedpur, Jharkhand, India
| | - J K Laik
- Consultant, Department of Pathology, Tata Main Hospital, Jamshedpur, Jharkhand, India
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13
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Hum JM, O'Bryan L, Smith RC, White KE. Novel functions of circulating Klotho. Bone 2017; 100:36-40. [PMID: 27890549 PMCID: PMC5441975 DOI: 10.1016/j.bone.2016.11.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 01/08/2023]
Abstract
A significant portion of the key biological functions of αKlotho (αKL) and its cognate ligand Fibroblast growth factor-23 (FGF23) have been revealed through the study of rare diseases of mineral metabolism. These findings have far reaching implications for common disorders such as chronic kidney disease-mineral bone disorder (CKD-MBD). αKL's predominant effect on mineral homeostasis is through its actions in the kidney as a co-receptor for FGF23, however emerging data has shed light on its capacity to act as a circulating factor through the cleavage of the transmembrane form of αKL ('mKL') to produce 'cleaved KL' or 'cKL'. This review summarizes new findings from studies using extended delivery of cKL to mouse models with phenotypes reflecting those arising in CKD-MBD.
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Affiliation(s)
- Julia M Hum
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Biomedical Science, Marian University School of Osteopathic Medicine, Indianapolis, IN 46222, USA
| | - Linda O'Bryan
- Biotechnology Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Rosamund C Smith
- Biotechnology Discovery Research, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285, USA
| | - Kenneth E White
- Department of Medical and Molecular Genetics, Division of Molecular Genetics and Gene Therapy, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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14
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Masi L, Beltrami G, Ottanelli S, Franceschelli F, Gozzini A, Zonefrati R, Galli G, Ciuffi S, Mavilia C, Giusti F, Marcucci G, Cioppi F, Colli E, Fossi C, Franchi A, Casentini C, Capanna R, Brandi ML. Human Preosteoblastic Cell Culture from a Patient with Severe Tumoral Calcinosis-Hyperphosphatemia Due to a New GALNT3 Gene Mutation: Study of In Vitro Mineralization. Calcif Tissue Int 2015; 96:438-52. [PMID: 25899975 DOI: 10.1007/s00223-015-9974-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 02/24/2015] [Indexed: 02/08/2023]
Abstract
Human disorders of phosphate (Pi) handling and skeletal mineralization represent a group of rare bone diseases. One of these disease is tumoral calcinosis (TC). In this study, we present the case of a patient with TC with a new GALNT3 gene mutation. We also performed functional studies using an in vitro cellular model. Genomic DNA was extracted from peripheral blood collected from a teenage Caucasian girl affected by TC, and from her parents. A higher capability to form mineralization nodules in vitro was found in human preosteoblastic cells of mutant when compared to wild-type controls. We found a novel homozygous inactivating splice site mutation in intron I (c.516-2a>g). A higher capability to form mineralization nodules in vitro was found in the mutant cells in human preosteoblastic cells when compared to wild-type controls. Understanding the functional significance and molecular physiology of this novel mutation will help to define the role of FGF23 in the control of Pi homeostasis in normal and in pathological conditions.
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Affiliation(s)
- L Masi
- Metabolic Bone Diseases Unit AOUC-Careggi, Department of Orthopedics, University of Florence, Largo Palagi, 1, 50134, Florence, Italy
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Ghafouri-Fard S, Abbasi F, Azizi F, Javaheri M, Mehdizadeh M, Setoodeh A. Hyperostosis-hyperphosphatemia syndrome (HHS): report of two cases with a recurrent mutation and review of the literature. J Pediatr Endocrinol Metab 2015; 28:231-5. [PMID: 25153226 DOI: 10.1515/jpem-2014-0178] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 06/24/2014] [Indexed: 11/15/2022]
Abstract
Hyperostosis-hyperphosphatemia syndrome (HHS) is a rare autosomal recessive metabolic disorder caused by mutations in the GALNT3 and FGF23 genes. The main features of this disorder include painful swelling of long bones, increased renal reabsorption of phosphate but normal renal function and vitamin D and parathormone levels. Previously, we reported a novel missense mutation in the FGF23 gene in a patient suffering from HHS. In the present report, we demonstrated the same mutation (c.471C>A) in two other cases of HHS with similar clinical manifestations. As this nucleotide change has not been reported previously, it can be a population specific mutation in Iran that can facilitate carrier testing and prenatal diagnosis of HHS.
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Rafaelsen S, Johansson S, Ræder H, Bjerknes R. Long-term clinical outcome and phenotypic variability in hyperphosphatemic familial tumoral calcinosis and hyperphosphatemic hyperostosis syndrome caused by a novel GALNT3 mutation; case report and review of the literature. BMC Genet 2014; 15:98. [PMID: 25249269 PMCID: PMC4181413 DOI: 10.1186/s12863-014-0098-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 09/04/2014] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Hyperphosphatemic Familial Tumoral Calcinosis (HFTC) and Hyperphosphatemic Hyperostosis Syndrome (HHS) are associated with autosomal recessive mutations in three different genes, FGF23, GALNT3 and KL, leading to reduced levels of fibroblast growth factor 23 (FGF23) and subsequent clinical effects. RESULTS We describe a consanguineous family with two affected siblings with HFTC and HHS caused by a novel homozygous G-to T substitution in exon 3 of GALNT3 (c.767 G > T; p.Gly256Val), demonstrating great phenotypic variation and long asymptomatic intervals. Calcific tumors appeared at 14 years of age in the male, and the female displayed episodic diaphysitis from age 9 years. Symptoms of eye involvement were present in both from childhood, and progressed into band keratopathy in the female. Abnormal dental roots and tooth loss, as well as myalgia were present in both from their mid-twenties, while the female also had calcifications in the placenta, the iliac vessels and thyroid cartilage. New calcific tumors appeared more than 20 years after the initial episodes, delaying diagnosis and treatment until the ages of 37 and 50 years, respectively. Both siblings had elevated serum phosphate levels, inappropriately elevated tubular maximum phosphate reabsorption per unit glomerular filtration rate (TmP/GFR), reduced levels of intact FGF23 and increased levels of c-terminal FGF23. Review of all 54 previously published cases of GALNT3, FGF23, and KL associated HFTC and HHS demonstrated that more subjects than previously recognized have a combined phenotype. CONCLUSION We have described HFTC and HHS in a consanguineous Caucasian family with a novel GALNT3 mutation, demonstrating new phenotypic features and significant variability in the natural course of the disease. A review of the literature, show that more subjects than previously recognized have a combined phenotype of HFTC and HHS. HHS and HFTC are two distinct phenotypes in a spectrum of GALNT3 mutation related calcification disorders, where the additional factors determining the phenotypic expression, are yet to be clarified.
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Affiliation(s)
- Silje Rafaelsen
- />Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Stefan Johansson
- />Department of Clinical Science, University of Bergen, Bergen, Norway
- />Center of Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Helge Ræder
- />Department of Clinical Science, University of Bergen, Bergen, Norway
- />Department of Pediatrics, Haukeland University Hospital, Bergen, Norway
| | - Robert Bjerknes
- />Department of Clinical Science, University of Bergen, Bergen, Norway
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Wagner CA, Rubio-Aliaga I, Biber J, Hernando N. Genetic diseases of renal phosphate handling. Nephrol Dial Transplant 2014; 29:iv45-iv54. [DOI: 10.1093/ndt/gfu217] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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Biber J, Murer H, Mohebbi N, Wagner C. Renal Handling of Phosphate and Sulfate. Compr Physiol 2014; 4:771-92. [DOI: 10.1002/cphy.c120031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Schjoldager KTBG, Clausen H. Site-specific protein O-glycosylation modulates proprotein processing - deciphering specific functions of the large polypeptide GalNAc-transferase gene family. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1820:2079-94. [PMID: 23022508 DOI: 10.1016/j.bbagen.2012.09.014] [Citation(s) in RCA: 149] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 09/17/2012] [Accepted: 09/19/2012] [Indexed: 01/18/2023]
Abstract
BACKGROUND Posttranslational modifications (PTMs) greatly expand the function and regulation of proteins, and glycosylation is the most abundant and diverse PTM. Of the many different types of protein glycosylation, one is quite unique; GalNAc-type (or mucin-type) O-glycosylation, where biosynthesis is initiated in the Golgi by up to twenty distinct UDP-N-acetyl-α-d-galactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc-Ts). These GalNAc-Ts are differentially expressed in cells and have different (although partly overlapping) substrate specificities, which provide for both unique functions and considerable redundancy. Recently we have begun to uncover human diseases associated with deficiencies in GalNAc-T genes (GALNTs). Thus deficiencies in individual GALNTs produce cell and protein specific effects and subtle distinct phenotypes such as hyperphosphatemia with hyperostosis (GALNT3) and dysregulated lipid metabolism (GALNT2). These phenotypes appear to be caused by deficient site-specific O-glycosylation that co-regulates proprotein convertase (PC) processing of FGF23 and ANGPTL3, respectively. SCOPE OF REVIEW Here we summarize recent progress in uncovering the interplay between human O-glycosylation and protease regulated processing and describes other important functions of site-specific O-glycosylation in health and disease. MAJOR CONCLUSIONS Site-specific O-glycosylation modifies pro-protein processing and other proteolytic events such as ADAM processing and thus emerges as an important co-regulator of limited proteolytic processing events. GENERAL SIGNIFICANCE Our appreciation of this function may have been hampered by our sparse knowledge of the O-glycoproteome and in particular sites of O-glycosylation. New strategies for identification of O-glycoproteins have emerged and recently the concept of SimpleCells, i.e. human cell lines made deficient in O-glycan extension by zinc finger nuclease gene targeting, was introduced for broad O-glycoproteome analysis.
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Esapa CT, Head RA, Jeyabalan J, Evans H, Hough TA, Cheeseman MT, McNally EG, Carr AJ, Thomas GP, Brown MA, Croucher PI, Brown SDM, Cox RD, Thakker RV. A mouse with an N-Ethyl-N-nitrosourea (ENU) Induced Trp589Arg Galnt3 mutation represents a model for hyperphosphataemic familial tumoural calcinosis. PLoS One 2012; 7:e43205. [PMID: 22912827 PMCID: PMC3418237 DOI: 10.1371/journal.pone.0043205] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 07/18/2012] [Indexed: 01/09/2023] Open
Abstract
Mutations of UDP-N-acetyl-alpha-D-galactosamine polypeptide N-acetyl galactosaminyl transferase 3 (GALNT3) result in familial tumoural calcinosis (FTC) and the hyperostosis-hyperphosphataemia syndrome (HHS), which are autosomal recessive disorders characterised by soft-tissue calcification and hyperphosphataemia. To facilitate in vivo studies of these heritable disorders of phosphate homeostasis, we embarked on establishing a mouse model by assessing progeny of mice treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU), and identified a mutant mouse, TCAL, with autosomal recessive inheritance of ectopic calcification, which involved multiple tissues, and hyperphosphataemia; the phenotype was designated TCAL and the locus, Tcal. TCAL males were infertile with loss of Sertoli cells and spermatozoa, and increased testicular apoptosis. Genetic mapping localized Tcal to chromosome 2 (62.64-71.11 Mb) which contained the Galnt3. DNA sequence analysis identified a Galnt3 missense mutation (Trp589Arg) in TCAL mice. Transient transfection of wild-type and mutant Galnt3-enhanced green fluorescent protein (EGFP) constructs in COS-7 cells revealed endoplasmic reticulum retention of the Trp589Arg mutant and Western blot analysis of kidney homogenates demonstrated defective glycosylation of Galnt3 in Tcal/Tcal mice. Tcal/Tcal mice had normal plasma calcium and parathyroid hormone concentrations; decreased alkaline phosphatase activity and intact Fgf23 concentrations; and elevation of circulating 1,25-dihydroxyvitamin D. Quantitative reverse transcriptase-PCR (qRT-PCR) revealed that Tcal/Tcal mice had increased expression of Galnt3 and Fgf23 in bone, but that renal expression of Klotho, 25-hydroxyvitamin D-1α-hydroxylase (Cyp27b1), and the sodium-phosphate co-transporters type-IIa and -IIc was similar to that in wild-type mice. Thus, TCAL mice have the phenotypic features of FTC and HHS, and provide a model for these disorders of phosphate metabolism.
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Affiliation(s)
- Christopher T. Esapa
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Rosie A. Head
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Jeshmi Jeyabalan
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
| | - Holly Evans
- The Mellanby Centre for Bone Research, Department of Human Metabolism, University of Sheffield, Sheffield, United Kingdom
| | - Tertius A. Hough
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Michael T. Cheeseman
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Eugene G. McNally
- Department of Radiology, Nuffield Orthopaedic Centre and Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, United Kingdom
| | - Andrew J. Carr
- NIHR Biomedical Research Unit, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, United Kingdom
| | - Gethin P. Thomas
- University of Queensland Diamantina Institute, Princess Alexandra Hospital, University of Queensland, Australia
| | - Matthew A. Brown
- University of Queensland Diamantina Institute, Princess Alexandra Hospital, University of Queensland, Australia
| | - Peter I. Croucher
- The Mellanby Centre for Bone Research, Department of Human Metabolism, University of Sheffield, Sheffield, United Kingdom
- Garvan Institute for Medical Research, Sydney, Australia
| | - Steve D. M. Brown
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Roger D. Cox
- Medical Research Council (MRC) Mammalian Genetics Unit and Mary Lyon Centre, MRC Harwell, Harwell Science and Innovation Campus, United Kingdom
| | - Rajesh V. Thakker
- Academic Endocrine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Oxford, United Kingdom
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Abstract
Glycosylation is an essential process by which sugars are attached to proteins and lipids. Complete lack of glycosylation is not compatible with life. Because of the widespread function of glycosylation, inherited disorders of glycosylation are multisystemic. Since the identification of the first defect on N-linked glycosylation in the 1980s, there are over 40 different congenital protein hypoglycosylation diseases. This review will include defects of N-linked glycosylation, O-linked glycosylation and disorders of combined N- and O-linked glycosylation.
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Affiliation(s)
- Susan E Sparks
- Department of Pediatrics, Levine Children's Hospital at Carolinas Medical Center, Charlotte, NC, USA; Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC, USA
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Abstract
Calcium (Ca(2+)) and phosphate (PO(4)(3-)) homeostasis are coordinated by systemic and local factors that regulate intestinal absorption, influx and efflux from bone, and kidney excretion and reabsorption of these ions through a complex hormonal network. Traditionally, the parathyroid hormone (PTH)/vitamin D axis provided the conceptual framework to understand mineral metabolism. PTH secreted by the parathyroid gland in response to hypocalcemia functions to maintain serum Ca(2+) levels by increasing Ca(2+) reabsorption and 1,25-dihydroxyvitamin D [1,25(OH)(2)D] production by the kidney, enhancing Ca(2+) and PO(4)(3-) intestinal absorption and increasing Ca(2+) and PO(4)(3-) efflux from bone, while maintaining neutral phosphate balance through phosphaturic effects. FGF23 is a recently discovered hormone, predominately produced by osteoblasts/osteocytes, whose major functions are to inhibit renal tubular phosphate reabsorption and suppress circulating 1,25(OH)(2)D levels by decreasing Cyp27b1-mediated formation and stimulating Cyp24-mediated catabolism of 1,25(OH)(2)D. FGF23 participates in a new bone/kidney axis that protects the organism from excess vitamin D and coordinates renal PO(4)(3-) handling with bone mineralization/turnover. Abnormalities of FGF23 production underlie many inherited and acquired disorders of phosphate homeostasis. This review discusses the known and emerging functions of FGF23, its regulation in response to systemic and local signals, as well as the implications of FGF23 in different pathological and physiological contexts.
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Affiliation(s)
- Aline Martin
- University of Tennessee Health Science Center, Memphis, Tennessee, USA
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Yancovitch A, Hershkovitz D, Indelman M, Galloway P, Whiteford M, Sprecher E, Kılıç E. Novel mutations in GALNT3 causing hyperphosphatemic familial tumoral calcinosis. J Bone Miner Metab 2011; 29:621-5. [PMID: 21347749 DOI: 10.1007/s00774-011-0260-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Accepted: 01/06/2011] [Indexed: 01/29/2023]
Abstract
Hyperphosphatemic familial tumoral calcinosis (HFTC) is known to be caused by mutations in at least three genes: FGF23, GALNT3 and KL. Two families with two affected members suffering from HFTC were scrutinized for mutations in these candidate genes. We identified in both families homozygous missense mutations affecting highly conserved amino acids in GALNT3. One of the mutations is a novel mutation, whereas the second mutation was reported before in a compound heterozygous state. Our data expand the spectrum of known mutations in GALNT3 and contribute to a better understanding of the phenotypic manifestations of mutations in this gene.
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Affiliation(s)
- Alan Yancovitch
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
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Zhang C, Gu J, Cheng X, Xiong K. Familial tumoral calcinosis in two Chinese patients: a case series. J Med Case Rep 2011; 5:394. [PMID: 21854601 PMCID: PMC3174129 DOI: 10.1186/1752-1947-5-394] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Accepted: 08/19/2011] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Tumoral calcinosis is a rare and benign condition characterized by massive subcutaneous soft tissue deposits of calcium phosphate predominantly around large joints. CASE PRESENTATION Familial tumoral calcinosis was present in two members of a Han Chinese family, namely, the son and daughter. The 14-year-old son had the first operation on his right sole of the foot at the age of six, and then experienced subsequent surgeries at a lesion in his right sole of the foot and left hip, respectively. The 16-year-old daughter underwent her first operation at the age of six in her left gluteal region, and subsequent surgeries were performed due to recurrence at the same lesion. Pathologic diagnoses of surgical specimens in both of the patients were reported as tumoral calcinosis. The laboratory results showed hyperphosphatemia with normal levels of serum calcium and alkaline phosphatase. Only surgical treatment was performed in both patients with satisfactory prognosis. CONCLUSION This is the first report of Chinese familial tumoral calcinosis. The etiopathogenisis and treatment are discussed.
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Affiliation(s)
- Che Zhang
- Taihe Hospital affiliated to Hubei Medical University, No, 32 South People's Road, Shiyan, Hubei Province, 442000, P,R,China.
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Mazzaferro S, Pasquali M, Pirrò G, Rotondi S, Tartaglione L. The bone and the kidney. Arch Biochem Biophys 2010; 503:95-102. [PMID: 20599669 DOI: 10.1016/j.abb.2010.06.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 06/24/2010] [Accepted: 06/26/2010] [Indexed: 12/21/2022]
Abstract
Renal tubular diseases may present with osteopenia, osteoporosis or osteomalacia, as a result of significant derangements in body electrolytes. In case of insufficient synthesis of calcitriol, as in renal failure, the more complex picture of renal osteodystrophy may develop. Hypothetically, also disturbed renal production of BMP-7 and Klotho could cause bone disease. However, the acknowledgment that osteocytes are capable of producing FGF23, a phosphaturic hormone at the same time modulating renal synthesis of calcitriol, indicates that it is also bone that can influence renal function. Importantly, a feed-back mechanism exists between FGF23 and calcitriol synthesis, while Klotho, produced by the kidney, determines activity and selectivity of FGF23. Identification of human diseases linked to disturbed production of FGF23 and Klotho underlines the importance of this new bone-kidney axis. Kidney and bone communicate reciprocally to regulate the sophisticated machinery responsible for divalent ions homeostasis and for osseous or extraosseous mineralisation processes.
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Ichikawa S, Baujat G, Seyahi A, Garoufali AG, Imel EA, Padgett LR, Austin AM, Sorenson AH, Pejin Z, Topouchian V, Quartier P, Cormier-Daire V, Dechaux M, Malandrinou FC, Singhellakis PN, Le Merrer M, Econs MJ. Clinical variability of familial tumoral calcinosis caused by novel GALNT3 mutations. Am J Med Genet A 2010; 152A:896-903. [PMID: 20358599 PMCID: PMC3392654 DOI: 10.1002/ajmg.a.33337] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The GALNT3 gene encodes GalNAc-T3, which prevents degradation of the phosphaturic hormone, fibroblast growth factor 23 (FGF23). Biallelic mutations in either GALNT3 or FGF23 result in hyperphosphatemic familial tumoral calcinosis or its variant, hyperostosis-hyperphosphatemia syndrome. Tumoral calcinosis is characterized by the presence of ectopic calcifications around major joints, whereas hyperostosis-hyperphosphatemia syndrome is characterized by recurrent long bone lesions with hyperostosis. Here we investigated four patients with hyperphosphatemia and clinical manifestations including tumoral calcinosis and/or hyperostosis-hyperphosphatemia syndrome to determine underlying genetic cause and delineate phenotypic heterogeneity of these disorders. Mutational analysis of FGF23 and GALNT3 in these patients revealed novel homozygous mutations in GALNT3. Although the presence of massive calcifications, cortical hyperostosis, or dental anomalies was not shared by all patients, all had persistent hyperphosphatemia. Three of the patients also had inappropriately normal 1,25-dihyroxyvitamin D [1,25(OH)(2)D] and confirmed low circulating intact FGF23 concentrations. The four novel GALNT3 mutations invariably resulted in hyperphosphatemia as a result of low intact FGF23, but other clinical manifestations were variable. Therefore, tumoral calcinosis and hyperostosis-hyperphosphatemia syndrome represent a continuous spectrum of the same disease caused by increased phosphate levels, rather than two distinct disorders.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
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Sprecher E. Familial tumoral calcinosis: from characterization of a rare phenotype to the pathogenesis of ectopic calcification. J Invest Dermatol 2010; 130:652-60. [PMID: 19865099 PMCID: PMC3169303 DOI: 10.1038/jid.2009.337] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Familial tumoral calcinosis (FTC) refers to a heterogeneous group of inherited disorders characterized by the occurrence of cutaneous and subcutaneous calcified masses. Two major forms of the disease are now recognized. Hyperphosphatemic FTC has been shown to result from mutations in three genes: fibroblast growth factor-23 (FGF23), coding for a potent phosphaturic protein, KL encoding Klotho, which serves as a co-receptor for FGF23, and GALNT3, which encodes a glycosyltransferase responsible for FGF23 O-glycosylation; defective function of any one of these three proteins results in hyperphosphatemia and ectopic calcification. The second form of the disease is characterized by absence of metabolic abnormalities, and is, therefore, termed normophosphatemic FTC. This variant was found to be associated with absence of functional SAMD9, a putative tumor suppressor and anti-inflammatory protein. The data gathered through the study of these rare disorders have recently led to the discovery of novel aspects of the pathogenesis of common disorders in humans, underscoring the potential concealed within the study of rare diseases.
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Affiliation(s)
- Eli Sprecher
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
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Fukumoto S. The role of bone in phosphate metabolism. Mol Cell Endocrinol 2009; 310:63-70. [PMID: 18822343 DOI: 10.1016/j.mce.2008.08.031] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2008] [Revised: 08/20/2008] [Accepted: 08/21/2008] [Indexed: 12/16/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is a humoral factor that is produced by osteocytes and reduces serum phosphate and 1,25-dihydroxyvitamin D levels by acting on kidney through some FGF receptor and Klotho. Excessive action of FGF23 results in several hypophosphatemic diseases characterized by impaired renal tubular phosphate reabsorption. In contrast, deficient action of FGF23 causes familial hyperphosphatemic tumoral calcinosis with enhanced renal tubular phosphate reabsorption. In addition, FGF23 null mice also show hyperphosphatemia. The production and circulatory level of FGF23 seem to be tightly regulated while the detailed mechanism of this regulation remains to be clarified. These results indicate that FGF23 is a physiological factor working as a hormone produced by bone. The discovery of FGF23 has revealed the possibility that bone produces several humoral factors to communicate with other organs.
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Affiliation(s)
- Seiji Fukumoto
- Division of Nephrology & Endocrinology, Department of Medicine, University of Tokyo Hospital, Tokyo, Japan.
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Chefetz I, Sprecher E. Familial tumoral calcinosis and the role of O-glycosylation in the maintenance of phosphate homeostasis. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:847-52. [PMID: 19013236 PMCID: PMC3169301 DOI: 10.1016/j.bbadis.2008.10.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 10/12/2008] [Accepted: 10/14/2008] [Indexed: 12/18/2022]
Abstract
Familial tumoral calcinosis refers to a group of disorders inherited in an autosomal recessive fashion. Hyperphosphatemic tumoral calcinosis is characterized by increased re-absorption of phosphate through the renal proximal tubule, resulting in elevated phosphate concentration and deposition of calcified deposits in cutaneous and subcutaneous tissues, as well as, occasionally, in visceral organs. The disease was found to result from mutations in at least 3 genes: GALNT3, encoding a glycosyltransferase termed ppGalNacT3, FGF23 encoding a potent phosphaturic protein, and KL encoding Klotho. Recent data showed that ppGalNacT3 mediates O-glycosylation of FGF23, thereby allowing for its secretion and possibly protecting it from proteolysis-mediated inactivation. Klotho was found to serve as a co-receptor for FGF23, thereby integrating the genetic data into a single physiological system. The elucidation of the molecular basis of HFTC shed new light upon the mechanisms regulating phosphate homeostasis, suggesting innovative therapeutic strategies for the management of hyperphosphatemia in common acquired conditions such as chronic renal failure.
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Affiliation(s)
- Ilana Chefetz
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Eli Sprecher
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Haifa, Israel
- Faculty of Medicine, Technion- Israel Institute of Technology, Haifa, Israel
- Department of Dermatology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
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Dumitrescu CE, Kelly MH, Khosravi A, Hart TC, Brahim J, White KE, Farrow EG, Nathan MH, Murphey MD, Collins MT. A case of familial tumoral calcinosis/hyperostosis-hyperphosphatemia syndrome due to a compound heterozygous mutation in GALNT3 demonstrating new phenotypic features. Osteoporos Int 2009; 20:1273-8. [PMID: 18982401 PMCID: PMC2692468 DOI: 10.1007/s00198-008-0775-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Accepted: 09/03/2008] [Indexed: 10/21/2022]
Abstract
SUMMARY A new case of familial tumoral calcinosis (FTC)/hyperostosis-hyperphosphatemia syndrome (HHS) due to a novel compound heterozygous mutation in N-acetylgalactosaminyltransferase 3 (GALNT3) and with new phenotypic findings is presented. The response in serum phosphate and fibroblast growth factor 23 (FGF23) to medical treatment is detailed. This case expands the genotype and phenotype of FTC/HHS and gives insight into its treatment and pathophysiology. INTRODUCTION FTC and HHS are caused by mutations in FGF23, GALNT3, or KLOTHO. They are characterized by hyperphosphatemia, increased phosphate reabsorption, and elevated or inappropriately normal serum 1,25-dihydroxyvitamin D(3) (1,25-D(3)); FTC is associated with calcific masses, and HHS with diaphyseal hyperostosis. METHODS A 36-year-old woman presented with abnormal dental X-rays at age 12 and was hyperphosphatemic at 22. She underwent radiographic, biochemical and genetic testing, and medical treatment. RESULTS Serum phosphorus was 7.3 mg/dL (2.5-4.8), TmP/GFR 6.99 mg/100 mL (2.97-4.45), 1,25-D(3) 35 pg/mL (22-67). Radiographs revealed tooth anomalies, thyroid cartilage calcification, calcific masses in vertebral spaces, calcification of the interstitial septa of the soft tissue in the lower extremities, and cortical thickening of the long bones. Her total hip Z score was 1.9. C-terminus serum FGF23 was 1,210 RU/mL (20-108), but intact FGF23 was 7.4 pg/mL (10-50). DNA sequencing determined she was a compound heterozygote for mutations in GALNT3. Treatment with niacinamide and acetazolamide decreased TmP/GFR and serum phosphate, which was paralleled by a decrease in serum C-terminus FGF23. CONCLUSIONS This case broadens the spectrum of phenotypic and genotypic features of FTC/HHS and suggests treatments to decrease renal phosphate reabsorption in the setting of a low intact FGF23.
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Affiliation(s)
- Claudia E. Dumitrescu
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Marilyn H. Kelly
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Azarmindokht Khosravi
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD, USA
- Kennedy Krieger Institute, Johns Hopkins University, Baltimore, MD, USA
| | - Thomas C. Hart
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD, USA
| | - Jaime Brahim
- Clinical Research Core, NIDCR, NIH, Bethesda, MD, USA
| | - Kenneth E. White
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Emily G. Farrow
- Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Muriel H. Nathan
- Department of Endocrinology, Diabetes and Metabolism, University of Vermont College of Medicine, Washington, D.C., USA
| | - Mark D. Murphey
- Department of Radiologic Pathology, AFIP, Washington, D.C., USA
| | - Michael T. Collins
- Skeletal Clinical Studies Unit, Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, Bethesda, MD, USA
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Ichikawa S, Sorenson AH, Austin AM, Mackenzie DS, Fritz TA, Moh A, Hui SL, Econs MJ. Ablation of the Galnt3 gene leads to low-circulating intact fibroblast growth factor 23 (Fgf23) concentrations and hyperphosphatemia despite increased Fgf23 expression. Endocrinology 2009; 150:2543-50. [PMID: 19213845 PMCID: PMC2689800 DOI: 10.1210/en.2008-0877] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Accepted: 02/02/2009] [Indexed: 12/24/2022]
Abstract
Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia. The disease is caused by inactivating mutations in fibroblast growth factor 23 (FGF23), Klotho (KL), and uridine diphosphate-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). In vitro studies indicate that GALNT3 O-glycosylates a phosphaturic hormone, FGF23, and prevents its proteolytic processing, thereby allowing secretion of intact FGF23. In this study we generated mice lacking the Galnt3 gene, which developed hyperphosphatemia without apparent calcifications. In response to hyperphosphatemia, Galnt3-deficient mice had markedly increased Fgf23 expression in bone. However, compared with wild-type and heterozygous littermates, homozygous mice had only about half of circulating intact Fgf23 levels and higher levels of C-terminal Fgf23 fragments in bone. Galnt3-deficient mice also exhibited an inappropriately normal 1,25-dihydroxyvitamin D level and decreased alkaline phosphatase activity. Furthermore, renal expression of sodium-phosphate cotransporters and Kl were elevated in Galnt3-deficient mice. Interestingly, there were sex-specific phenotypes; only Galnt3-deficient males showed growth retardation, infertility, and significantly increased bone mineral density. In summary, ablation of Galnt3 impaired secretion of intact Fgf23, leading to decreased circulating Fgf23 and hyperphosphatemia, despite increased Fgf23 expression. Our findings indicate that Galnt3-deficient mice have a biochemical phenotype of tumoral calcinosis and provide in vivo evidence that Galnt3 plays an essential role in proper secretion of Fgf23 in mice.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202-5121, USA
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Masi L, Gozzini A, Franchi A, Campanacci D, Amedei A, Falchetti A, Franceschelli F, Marcucci G, Tanini A, Capanna R, Brandi ML. A novel recessive mutation of fibroblast growth factor-23 in tumoral calcinosis. J Bone Joint Surg Am 2009; 91:1190-8. [PMID: 19411468 DOI: 10.2106/jbjs.h.00783] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND Tumoral calcinosis is a rare disease characterized by hyperphosphatemia due to hypophosphaturia and by ectopic calcifications. Phosphatonins are important hormones that regulate phosphorus homeostasis. Tumoral calcinosis is a rare congenital disorder in which the differential diagnosis from other syndromes associated with extraskeletal calcifications may be difficult. Mutations in the UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyltransferase-3 (GALNT3) and fibroblast growth factor-23 (FGF23) genes have been described. Mutational analysis is important for the early recognition of the disorder, for prevention of its complications, and for family screening strategies. We examined two unrelated white patients affected by tumoral calcinosis. METHODS The first patient was a woman with a history of an ectopic calcification in the left shoulder. The second patient was a man with a history of an ectopic calcification in the right buttock. Routine biochemistry and FGF-23 assays were performed on serum samples. Genomic DNA was extracted from peripheral blood. The FGF23 and GALNT3 genes were analyzed by direct sequencing. RESULTS A new homozygous H41Q codon 41, C-->A transversion at position 123 (c.123C>A) in exon 1 of the FGF23 gene was evidenced in both patients. No mutation of the GALNT3 gene was detected in these patients. As determined by an ELISA assay, intact FGF-23 circulating protein was low in both patients. CONCLUSIONS This is the fourth mutation of the FGF23 gene described in subjects with tumoral calcinosis.
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Affiliation(s)
- L Masi
- Department of Internal Medicine, University Hospital of Florence, Florence, Italy.
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Gok F, Chefetz I, Indelman M, Kocaoglu M, Sprecher E. Newly discovered mutations in the GALNT3 gene causing autosomal recessive hyperostosis-hyperphosphatemia syndrome. Acta Orthop 2009; 80:131-4. [PMID: 19297793 PMCID: PMC2823226 DOI: 10.1080/17453670902807482] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2008] [Accepted: 09/05/2008] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND AND PURPOSE Periosteal new bone formation and cortical hyperostosis often suggest an initial diagnosis of bone malignancy or osteomyelitis. In the present study, we investigated the cause of persistent bone hyperostosis in the offspring of two consanguineous parents. METHODS Clinical assessment, imaging, and direct sequencing were used to elucidate the etiology of the condition seen in the patient. RESULTS Radiological examination revealed periosteal reaction, diaphysitis, and cortical hyperostosis, suggesting osteomyelitis or a bone neoplasm. The clinical and radiological features were also reminiscent of hyperostosis with hyperphosphatemia (HHS), a rare autosomal recessive disease manifesting with recurrent, transient, and painful swelling of the long bones. The identification of two novel heterozygous pathogenic mutations in the GALNT3 gene confirmed a diagnosis of HHS. INTERPRETATION Molecular analysis represents an invaluable tool in the differential diagnosis of persistent cortical hyperostosis.
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Affiliation(s)
- Faysal Gok
- Department of Pediatric Nephrology, Gulhane Military Medical School, Ankara, Turkey
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Chefetz I, Kohno K, Izumi H, Uitto J, Richard G, Sprecher E. GALNT3, a gene associated with hyperphosphatemic familial tumoral calcinosis, is transcriptionally regulated by extracellular phosphate and modulates matrix metalloproteinase activity. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1792:61-7. [PMID: 18976705 PMCID: PMC3169302 DOI: 10.1016/j.bbadis.2008.09.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2008] [Revised: 09/29/2008] [Accepted: 09/29/2008] [Indexed: 12/16/2022]
Abstract
GALNT3 encodes UDP-N-acetyl-alpha-d-galactosamine: polypeptide N-acetylgalactosaminyl-transferarase 3 (ppGalNacT3), a glycosyltransferase which has been suggested to prevent proteolysis of FGF23, a potent phosphaturic protein. Accordingly, loss-of-function mutations in GALNT3 cause hyperphosphatemic familial tumoral calcinosis (HFTC), a rare autosomal recessive disorder manifesting with increased kidney reabsorption of phosphate, resulting in severe hyperphosphatemia and widespread ectopic calcifications. Although these findings definitely attribute a role to ppGalNacT3 in the regulation of phosphate homeostasis, little is currently known about the factors regulating GALNT3 expression. In addition, the effect of decreased GALNT3 expression in peripheral tissues has not been explored so far. In the present study, we demonstrate that GALNT3 expression is under the regulation of a number of factors known to be associated with phosphate homeostasis, including inorganic phosphate itself, calcium and 1,25-dihydroxyvitamin D(3). In addition, we show that decreased GALNT3 expression in human skin fibroblasts leads to increased expression of FGF7 and of matrix metalloproteinases, which have been previously implicated in the pathogenesis of ectopic calcification. Thus, the present data suggest that ppGalNacT3 may play a role in peripheral tissues of potential relevance to the pathogenesis of disorders of phosphate metabolism.
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Affiliation(s)
- Ilana Chefetz
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine Haifa, Technion – Israel Institute of Technology, Haifa, Israel
| | - Kimitoshi Kohno
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Hiroto Izumi
- Department of Molecular Biology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Jouni Uitto
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Gabriele Richard
- Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
- GeneDx, Gaithersburg, Maryland, USA
| | - Eli Sprecher
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
- Center for Translational Genetics, Rappaport Institute for Research in the Medical Sciences, Faculty of Medicine Haifa, Technion – Israel Institute of Technology, Haifa, Israel
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Bergwitz C, Jüppner H. Disorders of phosphate homeostasis and tissue mineralisation. ENDOCRINE DEVELOPMENT 2009; 16:133-56. [PMID: 19494665 PMCID: PMC3810012 DOI: 10.1159/000223693] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phosphate is absorbed from the diet in the gut, stored as hydroxyapatite in the skeleton, and excreted with the urine. The balance between these compartments determines the circulating phosphate concentration. Fibroblast growth factor 23 (FGF23) has recently been discovered and is part of a previously unrecognised hormonal bone-kidney axis. Phosphate-regulating gene with homologies to endopeptidases on the X chromosome, and dentin matrix protein 1 regulate the expression of FGF23 in osteocytes, which then is O-glycosylated by UDP-N-acetyl-alpha-D-galactosamine: polypeptide N-acetylgalactosaminyl-transferase 3 and secreted into the circulation. FGF23 binds with high affinity to fibroblast growth factor receptor 1c in the presence of its co-receptor Klotho. It inhibits, either directly or indirectly, reabsorption of phosphate and the synthesis of 1,25-dihydroxy-vitamin-D by the renal proximal tubule and the secretion of parathyroid hormone by the parathyroid glands. Acquired or inborn errors affecting this newly discovered hormonal system can lead to abnormal phosphate homeostasis and/or tissue mineralisation. This chapter will provide an update on the current knowledge of the pathophysiology, the clinical presentation, diagnostic evaluation and therapy of the disorders of phosphate homeostasis and tissue mineralisation.
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Affiliation(s)
- Clemens Bergwitz
- Endocrine Unit, Massachusetts General Hospital, Boston, MA 02114, USA.
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Garringer HJ, Malekpour M, Esteghamat F, Mortazavi SMJ, Davis SI, Farrow EG, Yu X, Arking DE, Dietz HC, White KE. Molecular genetic and biochemical analyses of FGF23 mutations in familial tumoral calcinosis. Am J Physiol Endocrinol Metab 2008; 295:E929-37. [PMID: 18682534 PMCID: PMC2575904 DOI: 10.1152/ajpendo.90456.2008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 08/03/2008] [Indexed: 11/22/2022]
Abstract
Fibroblast growth factor 23 (FGF23) is a hormone required for normal renal phosphate reabsorption. FGF23 gain-of-function mutations result in autosomal dominant hypophosphatemic rickets (ADHR), and FGF23 loss-of-function mutations cause familial hyperphosphatemic tumoral calcinosis (TC). In this study, we identified a novel recessive FGF23 TC mutation, a lysine (K) substitution for glutamine (Q) (160 C>A) at residue 54 (Q54K). To understand the molecular consequences of all known FGF23-TC mutants (H41Q, S71G, M96T, S129F, and Q54K), these proteins were stably expressed in vitro. Western analyses revealed minimal amounts of secreted intact protein for all mutants, and ELISA analyses demonstrated high levels of secreted COOH-terminal FGF23 fragments but low amounts of intact protein, consistent with TC patients' FGF23 serum profiles. Mutant protein function was tested and showed residual, yet decreased, bioactivity compared with wild-type protein. In examining the role of the FGF23 COOH-terminal tail (residues 180-251) in protein processing and activity, truncated mutants revealed that the majority of the residues downstream from the known FGF23 SPC protease site ((176)RXXR(179)/S(180)) were not required for protein secretion. However, residues adjacent to the RXXR site (between residues 188 and 202) were required for full bioactivity. In summary, we report a novel TC mutation and demonstrate a common defect of reduced FGF23 stability for all known FGF23-TC mutants. Finally, the majority of the COOH-terminal tail of FGF23 is not required for protein secretion but is required for full bioactivity.
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Affiliation(s)
- Holly J Garringer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
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Marcucci G, Masi L, Brandi ML. Phosphatonins: new hormones that control phosphorus homeostasis. Expert Rev Endocrinol Metab 2008; 3:513-526. [PMID: 30290433 DOI: 10.1586/17446651.3.4.513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Phosphorus (Pi) plays an important role in nucleic acid synthesis, energy metabolism, bone mineralization and cell signaling, and is also present in sugars, phospholipids and phosphoproteins. Phosphate homeostasis is controlled by processes that regulate the intestinal absorption and renal excretion of Pi, and bone turnover. These processes are influenced by peptide and sterol hormones, such as parathyroid hormone and 1α,25-dihydroxyvitamin D (1α,25[OH]2D3). Recently, a new class of phosphate-regulating peptides has been discovered: phosphatonins. These factors, such as FGF-23, secreted frizzled-related protein-4, matrix extracellular phosphoglycoprotein and FGF-7, are circulating peptides with potent phosphaturic activity. These peptides inhibit Na/Pi transporters in renal epithelial cells and, therefore, increase renal Pi excretion. In addition, FGF-23 and secreted frizzled-related protein-4 inhibit 25-hydroxyvitamin D 1α-hydroxylase activity, reducing 1α,25(OH)2D3 synthesis and, thus, intestinal Pi absorption. Phosphatonins have been associated with hypophosphatemic diseases, such as tumor-induced osteomalacia, X-linked hypophosphatemic rickets, autosomal dominant hypophosphatemic rickets, autosomal recessive hypophosphatemic rickets and hyperphosphatemic disease (e.g., tumoral calcinosis). The aim of this article is to review the role of phosphatonins in Pi metabolism in normal and pathologic conditions and also to investigate the correlations among the various phosphatonins.
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Affiliation(s)
- Gemma Marcucci
- a Department of Internal Medicine and # De Gene Spin-off, University of Florence, Medical School, Florence, Italy
| | - Laura Masi
- a Department of Internal Medicine and # De Gene Spin-off, University of Florence, Medical School, Florence, Italy
| | - Maria Luisa Brandi
- b Department of Internal Medicine, University of Florence, Viale Pieraccini 6, 50139 Florence, Italy.
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The genetic basis of inherited anomalies of the teeth. Part 2: syndromes with significant dental involvement. Eur J Med Genet 2008; 51:383-408. [PMID: 18599376 DOI: 10.1016/j.ejmg.2008.05.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Accepted: 05/02/2008] [Indexed: 12/20/2022]
Abstract
Teeth are specialized structural components of the craniofacial skeleton. Developmental defects occur either alone or in combination with other birth defects. In this paper, we review the dental anomalies in several multiple congenital anomaly (MCA) syndromes, in which the dental component is pivotal in the recognition of the phenotype and/or the molecular basis of the disorder is known. We will consider successively syndromic forms of amelogenesis imperfecta or enamel defects, dentinogenesis imperfecta (i.e. osteogenesis imperfecta) and other dentine anomalies. Focusing on dental aspects, we will review a selection of MCA syndromes associated with teeth number and/or shape anomalies. A better knowledge of the dental phenotype may contribute to an earlier diagnosis of some MCA syndromes involving teeth anomalies. They may serve as a diagnostic indicator or help confirm a syndrome diagnosis.
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Ichikawa S, Imel EA, Kreiter ML, Yu X, Mackenzie DS, Sorenson AH, Goetz R, Mohammadi M, White KE, Econs MJ. A homozygous missense mutation in human KLOTHO causes severe tumoral calcinosis. J Clin Invest 2008; 117:2684-91. [PMID: 17710231 PMCID: PMC1940239 DOI: 10.1172/jci31330] [Citation(s) in RCA: 349] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 05/25/2007] [Indexed: 01/12/2023] Open
Abstract
Familial tumoral calcinosis is characterized by ectopic calcifications and hyperphosphatemia due to inactivating mutations in FGF23 or UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 3 (GALNT3). Herein we report a homozygous missense mutation (H193R) in the KLOTHO (KL) gene of a 13-year-old girl who presented with severe tumoral calcinosis with dural and carotid artery calcifications. This patient exhibited defects in mineral ion homeostasis with marked hyperphosphatemia and hypercalcemia as well as elevated serum levels of parathyroid hormone and FGF23. Mapping of H193R mutation onto the crystal structure of myrosinase, a plant homolog of KL, revealed that this histidine residue was at the base of the deep catalytic cleft and mutation of this histidine to arginine should destabilize the putative glycosidase domain (KL1) of KL, thereby attenuating production of membrane-bound and secreted KL. Indeed, compared with wild-type KL, expression and secretion of H193R KL were markedly reduced in vitro, resulting in diminished ability of FGF23 to signal via its cognate FGF receptors. Taken together, our findings provide what we believe to be the first evidence that loss-of-function mutations in human KL impair FGF23 bioactivity, underscoring the essential role of KL in FGF23-mediated phosphate and vitamin D homeostasis in humans.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Erik A. Imel
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Mary L. Kreiter
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Xijie Yu
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Donald S. Mackenzie
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Andrea H. Sorenson
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Regina Goetz
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Moosa Mohammadi
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Kenneth E. White
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
| | - Michael J. Econs
- Department of Medicine and
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Division of Endocrinology, Children’s Memorial Hospital, Chicago, Illinois, USA.
Department of Pediatrics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.
Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana, USA.
Department of Pharmacology, New York University School of Medicine, New York, New York, USA
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Suzuki H, Amizuka N, Oda K, Noda M, Ohshima H, Maeda T. Involvement of the klotho protein in dentin formation and mineralization. Anat Rec (Hoboken) 2008; 291:183-90. [PMID: 18085632 DOI: 10.1002/ar.20630] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Klotho-deficient mice exhibit multiple pathological conditions resembling human aging. Our previous study showed alterations in the distribution of osteocytes and in the bone matrix synthesis in klotho-deficient mice. Although the bone and tooth share morphological features such as mineralization processes and components of the extracellular matrix, little information is available on how klotho deletion influences tooth formation. The present study aimed to elucidate the altered histology of incisors of klotho-deficient mice-comparing the findings with those from their wild-type littermates, by using immunohistochemistry for alkaline phosphatase (ALP), osteopontin, and dentin matrix protein-1 (DMP-1), terminal deoxynucleotidyl transferase-mediated deoxyuridinetriphosphate nick end-labeling (TUNEL) detection for apoptosis, and electron probe microanalyzer (EPMA) analysis on calcium (Ca), phosphate (P), and magnesium (Mg). Klotho-deficient incisors exhibited disturbed layers of odontoblasts, predentin, and dentin, resulting in an obscure dentin-predentinal border at the labial region. Several odontoblast-like cells without ALP activity were embedded in the labial dentin matrix, and immunopositivity for DMP-1 and osteopontin was discernible in the matrix surrounding these embedded odontoblast-like cells. TUNEL detection demonstrated an apoptotic reaction in the embedded odontoblast-like cells and pulpal cells in the klotho-deficient mice. EPMA revealed lower concentrations of Ca, P, and Mg in the klotho-deficient dentin, except for the dentin around abnormal odontoblast-like cells. These findings suggest the involvement of the klotho gene in dentinogenesis and its mineralization.
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Affiliation(s)
- Hironobu Suzuki
- Divisions of Anatomy and Cell Biology of the Hard Tissue, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
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Chefetz I, Ben Amitai D, Browning S, Skorecki K, Adir N, Thomas MG, Kogleck L, Topaz O, Indelman M, Uitto J, Richard G, Bradman N, Sprecher E. Normophosphatemic familial tumoral calcinosis is caused by deleterious mutations in SAMD9, encoding a TNF-alpha responsive protein. J Invest Dermatol 2007; 128:1423-9. [PMID: 18094730 DOI: 10.1038/sj.jid.5701203] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Normophosphatemic familial tumoral calcinosis (NFTC) is an autosomal recessive disorder characterized by calcium deposition in skin and mucosae and associated with unremitting pain and life-threatening skin infections. A homozygous missense mutation (p.K1495E), resulting in SAMD9 protein degradation, was recently shown to cause NFTC in five families of Jewish-Yemenite origin. In this study, we evaluated another Jewish-Yemenite NFTC kindred. All patients were compound heterozygous for two mutations in SAMD9: K1495E and a previously unreported nonsense mutation, R344X, predicted to result in a markedly truncated molecule. Screening of unaffected population-matched controls revealed heterozygosity for K1495E and R344X only in individuals of Jewish-Yemenite ancestry, but not in more than 700 control samples of other origins, including 93 non-Jewish Yemenite. These data may be suggestive of positive selection, considering the rarity of NFTC and the small size of the Jewish-Yemenite population; alternatively, they may reflect genetic drift or the effect of a population-specific modifier trait. Calcifications in NFTC generally develop over areas subjected to repeated trauma and are associated with marked inflammatory manifestations, indicating that SAMD9 may play a role in the inflammatory response to tissue injury. We therefore assessed the effect of cellular stress and tumor necrosis factor-alpha (TNF-alpha), a potent pro-inflammatory cytokine, on SAMD9 gene expression. Whereas exogenous hydrogen peroxide and heat shock did not affect SAMD9 transcription, osmotic shock was found to markedly upregulate SAMD9 expression. In addition, incubation of endothelial cells with TNF-alpha caused a dose-related, p38-dependant increase in SAMD9 expression. These data link NFTC and SAMD9 to the TNF-alpha signaling pathway, suggesting a role for this system in the regulation of extra-osseous calcification.
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Affiliation(s)
- Ilana Chefetz
- Laboratory of Molecular Dermatology and Department of Dermatology, Rambam Health Care Campus, Haifa, Israel
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Garringer HJ, Mortazavi SMJ, Esteghamat F, Malekpour M, Boztepe H, Tanakol R, Davis SI, White KE. Two novel GALNT3 mutations in familial tumoral calcinosis. Am J Med Genet A 2007; 143A:2390-6. [PMID: 17853462 DOI: 10.1002/ajmg.a.31947] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Familial tumoral calcinosis (TC) is characterized by elevated serum phosphate concentrations, normal or elevated 1,25(OH)2 vitamin D, as well as periarticular and vascular calcifications. Recessive mutations in the mucin-like glycosyltransferase GalNAc transferase-3 (GALNT3) and the phosphaturic hormone fibroblast growth factor-23 (FGF23) have been shown to result in TC. In the present study, mutational analyses were performed on two patients with TC to determine the molecular basis of their diseases. Analysis of the first patient revealed a novel, homozygous base insertion (1102_1103insT) in GALNT3 exon 5 that results in a frameshift and premature stop codon (E375X). The second patient had a novel homozygous transition (1460 g>a) in GALNT3 exon 7, which caused a nonsense mutation (W487X). Both mutations are predicted to markedly truncate the mature GALNT3 protein product. Although the patients carry GALNT3 mutations, these individuals presented with low-normal serum concentrations of intact biologically active FGF23 and high levels of C-terminal FGF23. In order to discern a possible relationship between GALNT3 and FGF23 in TC, a comprehensive assessment of the reported TC mutations was also performed. In summary, we have detected novel GALNT3 mutations that result in familial TC, and show that disturbed serum FGF23 concentrations are present in our TC cases as well as in previously reported cases. These studies expand our current genetic understanding of familial TC, and support a pathophysiological association between GALNT3 and FGF23.
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Affiliation(s)
- Holly J Garringer
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA, and Department of Orthopedics, Imam Khomeini University Hospital, Tehran, Iran
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Abstract
Congenital disorders of glycosylation (CDG) are a large family of genetic diseases resulting from defects in the synthesis of glycans and in the attachment of glycans to other compounds. These disorders cause a wide range of human diseases, with examples emanating from all medical subspecialties. Since our 2001 review on CDG ( 36 ), this field has seen substantial growth: The number of N-glycosylation defects has doubled (from 6 to 12), five new O-glycosylation defects have been added to the two previously known ones, three combined N- and O-glycosylation defects have been identified, the first lipid glycosylation defects have been discovered, and a new domain, that of the hyperglycosylation defects, has been introduced. A number of CDG are due to defects in enzymes with a putative glycosyltransferase function. There is also a growing group of patients with unidentified defects (CDG-x), some with typical clinical presentations and others with presentations not seen before in CDG. This review focuses on the clinical, biochemical, and genetic characteristics of CDG and on advances expected in their future study and clinical management.
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Affiliation(s)
- Jaak Jaeken
- Department of Pediatrics, Center for Metabolic Disease, University of Leuven, Leuven, Belgium.
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Abstract
Dentin, the most abundant tissue in teeth, is produced by odontoblasts, which differentiate from mesenchymal cells of the dental papilla. Dentinogenesis is a highly controlled process that results in the conversion of unmineralized predentin to mineralized dentin. By weight, 70% of the dentin matrix is mineralized, while the organic phase accounts for 20% and water constitutes the remaining 10%. Type I collagen is the primary component (>85%) of the organic portion of dentin. The non-collagenous part of the organic matrix is composed of various proteins, with dentin phosphoprotein predominating, accounting for about 50% of the non-collagenous part. Dentin defects are broadly classified into two major types: dentinogenesis imperfectas (DIs, types I-III) and dentin dysplasias (DDs, types I and II). To date, mutations in DSPP have been found to underlie the dentin disorders DI types II and III and DD type II. With the elucidation of the underlying genetic mechanisms has come the realization that the clinical characteristics associated with DSPP mutations appear to represent a continuum of phenotypes. Thus, these disorders should likely be called DSPP-associated dentin defects, with DD type II representing the mild end of the phenotypic spectrum and DI type III representing the severe end.
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Affiliation(s)
- P Suzanne Hart
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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Sprecher E. Tumoral calcinosis: new insights for the rheumatologist into a familial crystal deposition disease. Curr Rheumatol Rep 2007; 9:237-42. [PMID: 17531178 DOI: 10.1007/s11926-007-0038-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
A growing body of evidence points to extraosseous calcification (calcification occurring in nonosseous tissues) as a major cause of morbidity and mortality in humans. The term familial tumoral calcinosis encompasses a number of rare recessive diseases, often associated with increased reabsorption of phosphate through the renal proximal tubule, which manifests with periarticular or acral calcium deposition. Recently, the molecular pathogenesis of this group of disorders has been elucidated, leading to the identification of several proteins playing pivotal roles in the regulation of extraosseous calcification. This report reviews these advances as well as the potential implications of these discoveries for the management of acquired conditions associated with abnormal calcification.
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Affiliation(s)
- Eli Sprecher
- Laboratory of Molecular Dermatology, Department of Dermatology, Rambam Health Care Campus, Faculty of Medicine and Rappaport Institute for Research in the Medical Sciences, Technion, Israel.
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Abstract
There is a discontinuum of hereditary and acquired disorders of phosphate homeostasis that are caused by either high or low circulating levels of the novel phosphaturic hormone fibroblastic growth factor 23 (FGF23). Disorders that are caused by high circulating levels of FGF23 are characterized by hypophosphatemia, decreased production of 1,25-dihydroxyvitamin D, and rickets/osteomalacia. On the other end of the spectrum are disorders that are caused by low circulating levels of FGF23, which are characterized by hyperphosphatemia, elevated production of 1,25-dihydroxyvitamin D, soft tissue calcifications, and hyperostosis. Knowledge of the genetic basis of these hereditary disorders of phosphate homeostasis and studies of their mouse homologues have uncovered a bone-kidney axis and new systems biology that govern bone mineralization, vitamin D metabolism, parathyroid gland function, and renal phosphate handling. Further understanding of this primary phosphate homeostatic pathway has the potential to have a significant impact on the diagnosis and treatment of disorders of bone and mineral metabolism.
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Affiliation(s)
- Shiguang Liu
- Kidney Institute, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA
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Ichikawa S, Guigonis V, Imel EA, Courouble M, Heissat S, Henley JD, Sorenson AH, Petit B, Lienhardt A, Econs MJ. Novel GALNT3 mutations causing hyperostosis-hyperphosphatemia syndrome result in low intact fibroblast growth factor 23 concentrations. J Clin Endocrinol Metab 2007; 92:1943-7. [PMID: 17311862 DOI: 10.1210/jc.2006-1825] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
CONTEXT Hyperostosis-hyperphosphatemia syndrome (HHS) is a rare metabolic disorder characterized by hyperphosphatemia and localized hyperostosis. HHS is caused by mutations in GALNT3, which encodes UDP-N-acetyl-alpha-D-galactosamine:polypeptide N- acetylgalactosaminyltransferase 3. Familial tumoral calcinosis (TC), characterized by ectopic calcifications and hyperphosphatemia, is caused by mutations in the GALNT3 or fibroblast growth factor 23 (FGF23) genes. OBJECTIVE Our objective was to identify mutations in FGF23 or GALNT3 and determine serum FGF23 levels in an HHS patient. DESIGN Mutation detection in FGF23 and GALNT3 was performed by DNA sequencing, and serum FGF23 concentrations were measured by ELISA. PATIENTS OR OTHER PARTICIPANTS A 5-year-old French boy with HHS and his family members participated. RESULTS The patient presented with painful cortical lesions in his leg. Radiographs of the affected bone showed diaphyseal hyperostosis. The lesional tissue comprised trabeculae of immature, woven bone surrounded by fibrous tissue. Biochemistry revealed elevated phosphate, tubular maximum rate for phosphate reabsorption per deciliter of glomerular filtrate, and 1,25-dihydroxyvitamin D levels. The patient was a compound heterozygote for two novel GALNT3 mutations. His parents and brother were heterozygous for one of the mutations and had no biochemical abnormalities. Intact FGF23 level in the patient was low normal, whereas C-terminal FGF23 was elevated, a pattern similar to TC. CONCLUSION The presence of GALNT3 mutations and elevated C-terminal, but low intact serum FGF23, levels in HHS resemble those seen in TC, suggesting that HHS and TC are different manifestations of the same disorder. The absence of biochemical abnormalities in the heterozygous individuals suggests that one normal allele is sufficient for secretion of intact FGF23.
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Affiliation(s)
- Shoji Ichikawa
- Department of Medicine, Indiana University School of Medicine, 541 North Clinical Drive, Clinical Building 459, Indianapolis, IN 46202-5121, USA
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Barbieri AM, Filopanti M, Bua G, Beck-Peccoz P. Two novel nonsense mutations in GALNT3 gene are responsible for familial tumoral calcinosis. J Hum Genet 2007; 52:464-468. [PMID: 17351710 DOI: 10.1007/s10038-007-0126-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2006] [Accepted: 02/08/2007] [Indexed: 12/17/2022]
Abstract
Ectopic periarticular calcifications associated with elevated levels of serum phosphate represent the principal clinical features of hyperphosphatemic familial tumoral calcinosis (HFTC), a rare autosomal recessive metabolic disorder. The disease can be caused by recessive mutations in at least two different genes: GalNAc transferase 3 (GALNT3), encoding a glycosyltransferase that initiates mucin-type O-glycosylation, and fibroblast growth factor 23 (FGF23), which encodes a regulator of phosphate circulating levels. In the current study, we performed mutation analyses of the GALNT3 gene in a subject with HFTC and in his relatives. Sequence analyses revealed that the proband was a compound heterozygote for two novel nonsense mutations in exon 4 (Y322X) and in exon 7 (Q481X). Cosegregation of the mutations with the disease within the family was confirmed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) analysis. This is the first report describing the simultaneous presence of two different stop codons in the coding sequence of the GALNT3 gene.
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Affiliation(s)
- Anna Maria Barbieri
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy.
| | - Marcello Filopanti
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy
| | - Guido Bua
- Servizio di Neurologia, Policlinico Sassarese, Sassari, Italy
| | - Paolo Beck-Peccoz
- Department of Medical Sciences, Endocrine and Metabolic Unit, Pad. Granelli, University of Milan, Fondazione Policlinico IRCCS, Via Francesco Sforza 35, 20122, Milan, Italy
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Kato K, Clausen H. Role of Polypeptide GalNAc-transferase T3 in Familial Tumoral Calcinosis: The Importance of a Single GalNAc-transferase Isoform. TRENDS GLYCOSCI GLYC 2007. [DOI: 10.4052/tigg.19.265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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