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Hendrickx G, Boudin E, Mateiu L, Yorgan TA, Steenackers E, Kneissel M, Kramer I, Mortier G, Schinke T, Van Hul W. An Additional Lrp4 High Bone Mass Mutation Mitigates the Sost-Knockout Phenotype in Mice by Increasing Bone Remodeling. Calcif Tissue Int 2024; 114:171-181. [PMID: 38051321 DOI: 10.1007/s00223-023-01158-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/31/2023] [Indexed: 12/07/2023]
Abstract
Pathogenic variants disrupting the binding between sclerostin (encoded by SOST) and its receptor LRP4 have previously been described to cause sclerosteosis, a rare high bone mass disorder. The sclerostin-LRP4 complex inhibits canonical WNT signaling, a key pathway regulating osteoblastic bone formation and a promising therapeutic target for common bone disorders, such as osteoporosis. In the current study, we crossed mice deficient for Sost (Sost-/-) with our p.Arg1170Gln Lrp4 knock-in (Lrp4KI/KI) mouse model to create double mutant Sost-/-;Lrp4KI/KI mice. We compared the phenotype of Sost-/- mice with that of Sost-/-;Lrp4KI/KI mice, to investigate a possible synergistic effect of the disease-causing p.Arg1170Trp variant in Lrp4 on Sost deficiency. Interestingly, presence of Lrp4KI alleles partially mitigated the Sost-/- phenotype. Cellular and dynamic histomorphometry did not reveal mechanistic insights into the observed phenotypic differences. We therefore determined the molecular effect of the Lrp4KI allele by performing bulk RNA sequencing on Lrp4KI/KI primary osteoblasts. Unexpectedly, mostly genes related to bone resorption or remodeling (Acp5, Rankl, Mmp9) were upregulated in Lrp4KI/KI primary osteoblasts. Verification of these markers in Lrp4KI/KI, Sost-/- and Sost-/-;Lrp4KI/KI mice revealed that sclerostin deficiency counteracts this Lrp4KI/KI effect in Sost-/-;Lrp4KI/KI mice. We therefore hypothesize that models with two inactivating Lrp4KI alleles rather activate bone remodeling, with a net gain in bone mass, whereas sclerostin deficiency has more robust anabolic effects on bone formation. Moreover, these effects of sclerostin and Lrp4 are stronger in female mice, contributing to a more severe phenotype than in males and more detectable phenotypic differences among different genotypes.
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Affiliation(s)
- Gretl Hendrickx
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
- Department of Human Genetics, KU Leuven, Louvain, Belgium
| | - Eveline Boudin
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Ligia Mateiu
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Timur A Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ellen Steenackers
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Michaela Kneissel
- Diseases of Aging and Regenerative Medicine, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Ina Kramer
- Diseases of Aging and Regenerative Medicine, Novartis Institutes for BioMedical Research, Basel, Switzerland
| | - Geert Mortier
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
- Department of Human Genetics, KU Leuven, Louvain, Belgium
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wim Van Hul
- Centre for Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium.
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Hendrickx G, Boudin E, Steenackers E, Collet C, Mortier GR, Geneviève D, Van Hul W. A recessive form of craniodiaphyseal dysplasia caused by a homozygous missense variant in SP7/Osterix. Bone 2023; 167:116633. [PMID: 36436818 DOI: 10.1016/j.bone.2022.116633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 10/28/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, 2650 Edegem, Belgium; Laboratory for Skeletal Dysplasia Research, Department of Human Genetics, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, 2650 Edegem, Belgium
| | - Ellen Steenackers
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, 2650 Edegem, Belgium
| | - Corinne Collet
- INSERM U1132 and Université de Paris, Reference Centre for Rare Bone Diseases, Hospital Robert Debré, F-75010 Paris, France
| | - Geert R Mortier
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, 2650 Edegem, Belgium; Laboratory for Skeletal Dysplasia Research, Department of Human Genetics, KU Leuven, Herestraat 49, 3000 Leuven, Belgium; Center for Human Genetics, University Hospital Leuven, Leuven, Belgium
| | - David Geneviève
- Montpellier University and INSERM U1183, Montpellier, France; Competence Center for Bone Diseases, Clinical Genetics Unit, Montpellier University Hospital, Montpellier, France
| | - Wim Van Hul
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, 2650 Edegem, Belgium.
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Beyltjens T, Boudin E, Revencu N, Boeckx N, Bertrand M, Schütz L, Haack TB, Weber A, Biliouri E, Vinkšel M, Zagožen A, Peterlin B, Pai S, Telegrafi A, Henderson LB, Ells C, Turner L, Wuyts W, Van Hul W, Hendrickx G, Mortier GR. Heterozygous pathogenic variants involving CBFB cause a new skeletal disorder resembling cleidocranial dysplasia. J Med Genet 2022; 60:498-504. [PMID: 36241386 PMCID: PMC10176335 DOI: 10.1136/jmg-2022-108739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/03/2022] [Indexed: 11/03/2022]
Abstract
BACKGROUND Cleidocranial dysplasia (CCD) is a rare skeletal dysplasia with significant clinical variability. Patients with CCD typically present with delayed closure of fontanels and cranial sutures, dental anomalies, clavicular hypoplasia or aplasia and short stature. Runt-related transcription factor 2 (RUNX2) is currently the only known disease-causing gene for CCD, but several studies have suggested locus heterogeneity. METHODS The cohort consists of eight subjects from five unrelated families partially identified through GeneMatcher. Exome or genome sequencing was applied and in two subjects the effect of the variant was investigated at RNA level. RESULTS In each subject a heterozygous pathogenic variant in CBFB was detected, whereas no genomic alteration involving RUNX2 was found. Three CBFB variants (one splice site alteration, one nonsense variant, one 2 bp duplication) were shown to result in a premature stop codon. A large intragenic deletion was found to delete exon 4, without affecting CBFB expression. The effect of a second splice site variant could not be determined but most likely results in a shortened or absent protein. Affected individuals showed similarities with RUNX2-related CCD, including dental and clavicular abnormalities. Normal stature and neurocognitive problems were however distinguishing features. CBFB encodes the core-binding factor β subunit, which can interact with all RUNX proteins (RUNX1, RUNX2, RUNX3) to form heterodimeric transcription factors. This may explain the phenotypic differences between CBFB-related and RUNX2-related CCD. CONCLUSION We confirm the previously suggested locus heterogeneity for CCD by identifying five pathogenic variants in CBFB in a cohort of eight individuals with clinical and radiographic features reminiscent of CCD.
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Affiliation(s)
- Tessi Beyltjens
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Nicole Revencu
- Center for Human Genetics, Cliniques universitaires Saint-Luc and University of Louvain, Brussels, Belgium
| | - Nele Boeckx
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Miriam Bertrand
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Leon Schütz
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Axel Weber
- Institute of Human Genetics, Justus Liebig University, Giessen, Germany
| | - Eleni Biliouri
- Institute of Human Genetics, Justus Liebig University, Giessen, Germany
| | - Mateja Vinkšel
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana Division of Internal Medicine, Ljubljana, Slovenia
| | - Anja Zagožen
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana Division of Internal Medicine, Ljubljana, Slovenia
| | - Borut Peterlin
- Clinical Institute of Genomic Medicine, University Medical Centre Ljubljana Division of Internal Medicine, Ljubljana, Slovenia
| | - Shashidhar Pai
- Children's Health, Division of Genetics, Medical University of South Carolina, Charleston, South Carolina, USA
| | | | | | - Courtney Ells
- Provincial Medical Genetics Program, Eastern Health, St. John's, Newfoundland, Canada
| | - Lesley Turner
- Provincial Medical Genetics Program, Eastern Health, St. John's, Newfoundland, Canada.,Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Wim Wuyts
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium .,Department of Human Genetics, KU Leuven, Leuven, Belgium
| | - Geert R Mortier
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.,Department of Human Genetics, KU Leuven, Leuven, Belgium.,Center for Human Genetics, University Hospital Leuven, Leuven, Belgium
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Huybrechts Y, De Ridder R, De Samber B, Boudin E, Tonelli F, Knapen D, Schepers D, De Beenhouwer J, Sijbers J, Forlino A, Mortier G, Coucke P, Witten PE, Kwon R, Willaert A, Hendrickx G, Van Hul W. The sqstm1tmΔUBA zebrafish model, a proof-of-concept in vivo model for Paget’s disease of bone? Bone Rep 2022. [DOI: 10.1016/j.bonr.2022.101483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Lauffer P, Boudin E, van der Kaay DCM, Koene S, van Haeringen A, van Tellingen V, Van Hul W, Prickett TCR, Mortier G, Espiner EA, van Duyvenvoorde HA. Broadening the spectrum of loss-of-function variants in NPR-C-related extreme tall stature. J Endocr Soc 2022; 6:bvac019. [PMID: 35233476 PMCID: PMC8879884 DOI: 10.1210/jendso/bvac019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Indexed: 11/28/2022] Open
Abstract
Context Natriuretic peptide receptor-C (NPR-C, encoded by NPR3) belongs to a family of cell membrane–integral proteins implicated in various physiological processes, including longitudinal bone growth. NPR-C acts as a clearance receptor of natriuretic peptides, including C-type natriuretic peptide (CNP), that stimulate the cGMP-forming guanylyl cyclase-coupled receptors NPR-A and NPR-B. Pathogenic variants in CNP, NPR2, and NPR3 may cause a tall stature phenotype associated with macrodactyly of the halluces and epiphyseal dysplasia. Objective Here we report on a boy with 2 novel biallelic inactivating variants of NPR3. Methods History and clinical characteristics were collected. Biochemical indices of natriuretic peptide clearance and in vitro cellular localization of NPR-C were studied to investigate causality of the identified variants. Results We identified 2 novel compound heterozygous NPR3 variants c.943G>A p.(Ala315Thr) and c.1294A>T p.(Ile432Phe) in a boy with tall stature and macrodactyly of the halluces. In silico analysis indicated decreased stability of NPR-C, presumably resulting in increased degradation or trafficking defects. Compared to other patients with NPR-C loss-of-function, the phenotype seemed to be milder: pseudo-epiphyses in hands and feet were absent, biochemical features were less severe, and there was some co-localization of p.(Ile432Phe) NPR-C with the cell membrane, as opposed to complete cytoplasmic retention. Conclusion With this report on a boy with tall stature and macrodactyly of the halluces we further broaden the genotypic and phenotypic spectrum of NPR-C-related tall stature.
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Affiliation(s)
- Peter Lauffer
- Department of Pediatric Endocrinology, Emma Children’s Hospital, Amsterdam University Medical Center, Amsterdam, the Netherlands
| | - Eveline Boudin
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Daniëlle C M van der Kaay
- Department of Pediatric Endocrinology, Sophia Children’s Hospital, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Saskia Koene
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Arie van Haeringen
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Vera van Tellingen
- Department of Pediatrics, Catharina Hospital, Eindhoven, the Netherlands
| | - Wim Van Hul
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | | | - Geert Mortier
- Department of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Eric A Espiner
- Department of Medicine, University of Otago, Christchurch, New Zealand
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Huybrechts Y, Boudin E, Hendrickx G, Steenackers E, Hamdy N, Mortier G, Martínez Díaz-Guerra G, Bracamonte MS, Appelman-Dijkstra NM, Van Hul W. Identification of Compound Heterozygous Variants in LRP4 Demonstrates That a Pathogenic Variant outside the Third β-Propeller Domain Can Cause Sclerosteosis. Genes (Basel) 2021; 13:genes13010080. [PMID: 35052419 PMCID: PMC8774882 DOI: 10.3390/genes13010080] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/22/2021] [Accepted: 12/22/2021] [Indexed: 11/16/2022] Open
Abstract
Sclerosteosis is a high bone mass disorder, caused by pathogenic variants in the genes encoding sclerostin or LRP4. Both proteins form a complex that strongly inhibits canonical WNT signaling activity, a pathway of major importance in bone formation. So far, all reported disease-causing variants are located in the third β-propeller domain of LRP4, which is essential for the interaction with sclerostin. Here, we report the identification of two compound heterozygous variants, a known p.Arg1170Gln and a novel p.Arg632His variant, in a patient with a sclerosteosis phenotype. Interestingly, the novel variant is located in the first β-propeller domain, which is known to be indispensable for the interaction with agrin. However, using luciferase reporter assays, we demonstrated that both the p.Arg1170Gln and the p.Arg632His variant in LRP4 reduced the inhibitory capacity of sclerostin on canonical WNT signaling activity. In conclusion, this study is the first to demonstrate that a pathogenic variant in the first β-propeller domain of LRP4 can contribute to the development of sclerosteosis, which broadens the mutational spectrum of the disorder.
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Affiliation(s)
- Yentl Huybrechts
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
| | - Eveline Boudin
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
| | - Gretl Hendrickx
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
| | - Ellen Steenackers
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
| | - Neveen Hamdy
- Department of Internal Medicine, Division Endocrinology, Leiden University Medical Center, 2332 ZA Leiden, The Netherlands; (N.H.); (N.M.A.-D.)
| | - Geert Mortier
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
| | | | - Milagros Sierra Bracamonte
- Endocrinology and Nutrition Resident, 12 de Octubre University Hospital, 28041 Madrid, Spain; (G.M.D.-G.); (M.S.B.)
| | - Natasha M. Appelman-Dijkstra
- Department of Internal Medicine, Division Endocrinology, Leiden University Medical Center, 2332 ZA Leiden, The Netherlands; (N.H.); (N.M.A.-D.)
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and University Hospital Antwerp, 2650 Antwerp, Belgium; (Y.H.); (E.B.); (G.H.); (E.S.); (G.M.)
- Correspondence: ; Tel.: +32-(0)3-275-97-61
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De Ridder R, Vandeweyer G, Boudin E, Hendrickx G, Huybrechts Y, Cremers TC, Devogelaer JP, Mortier G, Fransen E, Van Hul W. A Panel-Based Sequencing Analysis of Patients with Paget's Disease of Bone Suggests Enrichment of Rare Genetic Variation in regulators of NF-κB Signaling and Supports the Importance of the 7q33 Locus. Calcif Tissue Int 2021; 109:656-665. [PMID: 34173013 DOI: 10.1007/s00223-021-00881-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/15/2021] [Indexed: 10/21/2022]
Abstract
Paget's disease of bone (PDB) is a common bone disorder characterized by focal lesions caused by increased bone turnover. Monogenic forms of PDB and PDB-related phenotypes as well as genome-wide association studies strongly support the involvement of genetic variation in components of the NF-κB signaling pathway in the pathogenesis of PDB. In this study, we performed a panel-based mutation screening of 52 genes. Single variant association testing and a series of gene-based association tests were performed. The former revealed a novel association with NFKBIA and further supports an involvement of variation in NR4A1, VCP, TNFRSF11A, and NUP205. The latter indicated a trend for enrichment of rare genetic variation in GAB2 and PRKCI. Both single variant tests and gene-based tests highlighted two genes, NR4A1 and NUP205. In conclusion, our findings support the involvement of genetic variation in modulators of NF-κB signaling in PDB and confirm the association of previously associated genes with the pathogenesis of PDB.
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Affiliation(s)
- Raphaël De Ridder
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Geert Vandeweyer
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Eveline Boudin
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Gretl Hendrickx
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Yentl Huybrechts
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Tycho Canter Cremers
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Jean-Pierre Devogelaer
- Department of Rheumatology, Saint-Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium
| | - Geert Mortier
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Erik Fransen
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Antwerp, Belgium.
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Martínez-Gil N, Roca-Ayats N, Atalay N, Pineda-Moncusí M, Garcia-Giralt N, Van Hul W, Boudin E, Ovejero D, Mellibovsky L, Nogués X, Díez-Pérez A, Grinberg D, Balcells S. Functional Assessment of Coding and Regulatory Variants From the DKK1 Locus. JBMR Plus 2020; 4:e10423. [PMID: 33354644 PMCID: PMC7745885 DOI: 10.1002/jbm4.10423] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Accepted: 10/03/2020] [Indexed: 12/17/2022] Open
Abstract
The DKK1 gene encodes an extracellular inhibitor of the Wnt pathway with an important role in bone tissue development, bone homeostasis, and different critical aspects of bone biology. Several BMD genome‐wide association studies (GWASs) have consistently found association with SNPs in the DKK1 genomic region. For these reasons, it is important to assess the functionality of coding and regulatory variants in the gene. Here, we have studied the functionality of putative regulatory variants, previously found associated with BMD in different studies by others and ourselves, and also six missense variants present in the general population. Using a Wnt‐pathway‐specific luciferase reporter assay, we have determined that the variants p.Ala41Thr, p.Tyr74Phe, p.Arg120Leu, and p.Ser157Ile display a reduced DKK1 inhibitory capacity as compared with WT. This result agrees with the high‐bone‐mass (HBM) phenotype of two women from our cohort who carried mutations p.Tyr74Phe or p.Arg120Leu. On the other hand, by means of a circularized chromosome conformation capture‐ (4C‐) sequencing experiment, we have detected that the region containing 24 BMD‐GWA variants, located 350‐kb downstream of DKK1, interacts both with DKK1 and the LNCAROD (LncRNA‐activating regulator of DKK1, AKA LINC0148) in osteoblastic cells. In conclusion, we have shown that some rare coding variants are partial loss‐of‐function mutations that may lead to a HBM phenotype, whereas the common SNPs associated with BMD in GWASs belong to a putative long‐range regulatory region, through a yet unknown mechanism involving LNCAROD. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Núria Martínez-Gil
- Department of Genetics, Microbiology and Statistics, Faculty of Biology Universitat de Barcelona, Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Institut de Biomedicina de la Universitat de Barcelona (IBUB), Institut de Recerca Sant Joan de Déu (IRSJD) Barcelona Spain
| | - Neus Roca-Ayats
- Department of Genetics, Microbiology and Statistics, Faculty of Biology Universitat de Barcelona, Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Institut de Biomedicina de la Universitat de Barcelona (IBUB), Institut de Recerca Sant Joan de Déu (IRSJD) Barcelona Spain
| | - Nurgül Atalay
- Department of Genetics, Microbiology and Statistics, Faculty of Biology Universitat de Barcelona, Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Institut de Biomedicina de la Universitat de Barcelona (IBUB), Institut de Recerca Sant Joan de Déu (IRSJD) Barcelona Spain
| | - Marta Pineda-Moncusí
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Natàlia Garcia-Giralt
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Wim Van Hul
- Center of Medical Genetics University of Antwerp & University Hospital Antwerp Antwerp Belgium
| | - Eveline Boudin
- Center of Medical Genetics University of Antwerp & University Hospital Antwerp Antwerp Belgium
| | - Diana Ovejero
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Leonardo Mellibovsky
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Xavier Nogués
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Adolfo Díez-Pérez
- Musculoskeletal Research Group, Hospital del Mar Medical Research Institute Centro de Investigación Biomédica en Red en Fragilidad y Envejecimiento Saludable, ISCIII Barcelona Spain
| | - Daniel Grinberg
- Department of Genetics, Microbiology and Statistics, Faculty of Biology Universitat de Barcelona, Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Institut de Biomedicina de la Universitat de Barcelona (IBUB), Institut de Recerca Sant Joan de Déu (IRSJD) Barcelona Spain
| | - Susanna Balcells
- Department of Genetics, Microbiology and Statistics, Faculty of Biology Universitat de Barcelona, Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Institut de Biomedicina de la Universitat de Barcelona (IBUB), Institut de Recerca Sant Joan de Déu (IRSJD) Barcelona Spain
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9
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Peeters S, Declerck K, Thomas M, Boudin E, Beckers D, Chivu O, Heinrichs C, Devriendt K, de Zegher F, Van Hul W, Vanden Berghe W, De Schepper J, Rooman R, Mortier G. DNA Methylation Profiling and Genomic Analysis in 20 Children with Short Stature Who Were Born Small for Gestational Age. J Clin Endocrinol Metab 2020; 105:5873625. [PMID: 32685970 DOI: 10.1210/clinem/dgaa465] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
PURPOSE In a significant proportion of children born small for gestational age (SGA) with failure of catch-up growth, the etiology of short stature remains unclear after routine diagnostic workup. We wanted to investigate if extensive analysis of the (epi)genome can unravel the cause of growth failure in a significant portion of these children. PATIENTS AND METHODS Twenty SGA children treated with GH because of short stature were selected from the BELGROW database of the Belgian Society for Pediatric Endocrinology and Diabetology for exome sequencing, single-nucleotide polymorphism (SNP) array and genome-wide methylation analysis to identify the (epi)genetic cause. First-year response to GH was compared with the response of SGA patients in the KIGS database. RESULTS We identified (likely) pathogenic variants in 4 children (from 3 families) using exome sequencing and found pathogenic copy number variants in 2 probands using SNP array. In a child harboring a NSD1-containing microduplication, we identified a DNA methylation signature that is opposite to the genome-wide DNA methylation signature of Sotos syndrome. Moreover, we observed multilocus imprinting disturbances in 2 children in whom no other genomic alteration could be identified. Five of 6 children with a genetic diagnosis had an "above average" response to GH. CONCLUSIONS The study indicates that a more advanced approach with deep genotyping can unravel unexpected (epi)genomic alterations in SGA children with persistent growth failure. Most SGA children with a genetic diagnosis had a good response to GH treatment.
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Affiliation(s)
- Silke Peeters
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Ken Declerck
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Muriel Thomas
- Belgian Society for Pediatric Endocrinology and Diabetology, Brussels, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Dominique Beckers
- Unité d'Endocrinologie Pédiatrique, CHU Namur, Université catholique de Louvain, Yvoir, Belgium and Department of Pediatrics, University Hospital Leuven, Leuven, Belgium
| | - Olimpia Chivu
- Department of Pediatrics, Clinique de l'Espérance, Saint-Nicolas, Belgium
| | - Claudine Heinrichs
- Paediatric Endocrinology Unit, Hôpital Universitaire des Enfants Reine Fabiola (HUDERF), Brussels, Belgium
| | - Koenraad Devriendt
- Center for Human Genetics, University of Leuven and the University Hospital Leuven, Leuven, Belgium
| | - Francis de Zegher
- Department of Development & Regeneration, University of Leuven, Leuven, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Wim Vanden Berghe
- Laboratory of Protein Chemistry, Proteomics and Epigenetic Signalling (PPES), Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Jean De Schepper
- Department of Pediatrics, Vrije Universiteit Brussel, Universitair Ziekenhuis Brussel, Brussels, Belgium and Department of Pediatrics, Universitair Ziekenhuis Gent, Ghent, Belgium
| | | | - Geert Mortier
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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10
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Palencia-Campos A, Aoto PC, Machal EMF, Rivera-Barahona A, Soto-Bielicka P, Bertinetti D, Baker B, Vu L, Piceci-Sparascio F, Torrente I, Boudin E, Peeters S, Van Hul W, Huber C, Bonneau D, Hildebrand MS, Coleman M, Bahlo M, Bennett MF, Schneider AL, Scheffer IE, Kibæk M, Kristiansen BS, Issa MY, Mehrez MI, Ismail S, Tenorio J, Li G, Skålhegg BS, Otaify GA, Temtamy S, Aglan M, Jønch AE, De Luca A, Mortier G, Cormier-Daire V, Ziegler A, Wallis M, Lapunzina P, Herberg FW, Taylor SS, Ruiz-Perez VL. Germline and Mosaic Variants in PRKACA and PRKACB Cause a Multiple Congenital Malformation Syndrome. Am J Hum Genet 2020; 107:977-988. [PMID: 33058759 DOI: 10.1016/j.ajhg.2020.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/09/2020] [Indexed: 12/19/2022] Open
Abstract
PRKACA and PRKACB code for two catalytic subunits (Cα and Cβ) of cAMP-dependent protein kinase (PKA), a pleiotropic holoenzyme that regulates numerous fundamental biological processes such as metabolism, development, memory, and immune response. We report seven unrelated individuals presenting with a multiple congenital malformation syndrome in whom we identified heterozygous germline or mosaic missense variants in PRKACA or PRKACB. Three affected individuals were found with the same PRKACA variant, and the other four had different PRKACB mutations. In most cases, the mutations arose de novo, and two individuals had offspring with the same condition. Nearly all affected individuals and their affected offspring shared an atrioventricular septal defect or a common atrium along with postaxial polydactyly. Additional features included skeletal abnormalities and ectodermal defects of variable severity in five individuals, cognitive deficit in two individuals, and various unusual tumors in one individual. We investigated the structural and functional consequences of the variants identified in PRKACA and PRKACB through the use of several computational and experimental approaches, and we found that they lead to PKA holoenzymes which are more sensitive to activation by cAMP than are the wild-type proteins. Furthermore, expression of PRKACA or PRKACB variants detected in the affected individuals inhibited hedgehog signaling in NIH 3T3 fibroblasts, thereby providing an underlying mechanism for the developmental defects observed in these cases. Our findings highlight the importance of both Cα and Cβ subunits of PKA during human development.
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Affiliation(s)
- Adrian Palencia-Campos
- Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Autónoma de Madrid (UAM), Madrid, 28029, Spain; CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, 28029, Spain
| | - Phillip C Aoto
- Department of Pharmacology, University of California, San Diego, 9400 Gilman Drive, La Jolla, CA 92093-0654, USA
| | - Erik M F Machal
- Institute for Biology, Department of Biochemistry, University of Kassel, Kassel, 34132, Germany
| | - Ana Rivera-Barahona
- Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Autónoma de Madrid (UAM), Madrid, 28029, Spain; CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, 28029, Spain
| | - Patricia Soto-Bielicka
- Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Autónoma de Madrid (UAM), Madrid, 28029, Spain
| | - Daniela Bertinetti
- Institute for Biology, Department of Biochemistry, University of Kassel, Kassel, 34132, Germany
| | - Blaine Baker
- Department of Pharmacology, University of California, San Diego, 9400 Gilman Drive, La Jolla, CA 92093-0654, USA
| | - Lily Vu
- Department of Pharmacology, University of California, San Diego, 9400 Gilman Drive, La Jolla, CA 92093-0654, USA
| | - Francesca Piceci-Sparascio
- Medical Genetics Unit, Casa Sollievo della Sofferenza Foundation, IRCCS, San Giovanni Rotondo, 71013, Italy
| | - Isabella Torrente
- Medical Genetics Unit, Casa Sollievo della Sofferenza Foundation, IRCCS, San Giovanni Rotondo, 71013, Italy
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Edegem, 2650, Belgium
| | - Silke Peeters
- Department of Medical Genetics, University of Antwerp, Edegem, 2650, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Edegem, 2650, Belgium
| | - Celine Huber
- Clinical Genetics and Reference Center for Skeletal Dysplasia, AP-HP, Necker-Enfants Malades Hospital, Paris, 75015, France; Université De Paris, INSERM UMR1163, Institut Imagine, Paris, 75015, France
| | - Dominique Bonneau
- Biochemistry and Genetics Department, Angers Hospital, Angers Cedex 9, 49933, France; UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers Cedex 9, 49933, France
| | - Michael S Hildebrand
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, 3084, Victoria, Australia; Murdoch Children's Research Institute, Parkville, 3052, Victoria, Australia
| | - Matthew Coleman
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, 3084, Victoria, Australia; Murdoch Children's Research Institute, Parkville, 3052, Victoria, Australia
| | - Melanie Bahlo
- Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, 3010, Victoria, Australia
| | - Mark F Bennett
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, 3084, Victoria, Australia; Population Health and Immunity Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, 3052, Victoria, Australia; Department of Medical Biology, University of Melbourne, Melbourne, 3010, Victoria, Australia
| | - Amy L Schneider
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, 3084, Victoria, Australia
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Heidelberg, 3084, Victoria, Australia; Murdoch Children's Research Institute, Parkville, 3052, Victoria, Australia; Department of Paediatrics, University of Melbourne, Royal Children's Hospital, and Florey Institute of Neuroscience and Mental Health, Parkville, 3052, Victoria, Australia
| | - Maria Kibæk
- Children's Hospital of H.C. Andersen, Odense University Hospital, 5000 Odense, Denmark
| | - Britta S Kristiansen
- Department of Clinical Genetics, Odense University Hospital, 5000 Odense, Denmark
| | - Mahmoud Y Issa
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Mennat I Mehrez
- Department of Oro-dental Genetics, Division of Human Genetics and Genome Research. Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Samira Ismail
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Jair Tenorio
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, 28029, Spain; Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz, Universidad Autónoma, Madrid, 28046, Spain; ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability
| | - Gaoyang Li
- Division for Molecular Nutrition, Institute for Basic Medical Sciences, University of Oslo, Oslo, 0316, Norway
| | - Bjørn Steen Skålhegg
- Division for Molecular Nutrition, Institute for Basic Medical Sciences, University of Oslo, Oslo, 0316, Norway
| | - Ghada A Otaify
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Samia Temtamy
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Mona Aglan
- Department of Clinical Genetics, Division of Human Genetics and Genome Research, Center of Excellence for Human Genetics, National Research Centre, Cairo, 12622, Egypt
| | - Aia E Jønch
- Department of Clinical Genetics, Odense University Hospital, 5000 Odense, Denmark
| | - Alessandro De Luca
- Medical Genetics Unit, Casa Sollievo della Sofferenza Foundation, IRCCS, San Giovanni Rotondo, 71013, Italy
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp, Edegem, 2650, Belgium; Antwerp University Hospital, Edegem, 2650, Belgium
| | - Valérie Cormier-Daire
- Clinical Genetics and Reference Center for Skeletal Dysplasia, AP-HP, Necker-Enfants Malades Hospital, Paris, 75015, France; Université De Paris, INSERM UMR1163, Institut Imagine, Paris, 75015, France
| | - Alban Ziegler
- Biochemistry and Genetics Department, Angers Hospital, Angers Cedex 9, 49933, France; UMR CNRS 6015-INSERM U1083, MitoVasc Institute, Angers University, Angers Cedex 9, 49933, France
| | - Mathew Wallis
- School of Medicine and Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, 7001, Australia; Clinical Genetics Service, Austin Health, Heidelberg, 3084, Victoria, Australia
| | - Pablo Lapunzina
- CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, 28029, Spain; Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz, Universidad Autónoma, Madrid, 28046, Spain; ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability
| | - Friedrich W Herberg
- Institute for Biology, Department of Biochemistry, University of Kassel, Kassel, 34132, Germany
| | - Susan S Taylor
- Department of Pharmacology, University of California, San Diego, 9400 Gilman Drive, La Jolla, CA 92093-0654, USA; Department of Chemistry and Biochemistry, University of California, San Diego, 9400 Gilman Drive, La Jolla, CA 92093-0654, USA
| | - Victor L Ruiz-Perez
- Instituto de Investigaciones Biomédicas "Alberto Sols," Consejo Superior de Investigaciones Científicas (CSIC)-Universidad Autónoma de Madrid (UAM), Madrid, 28029, Spain; CIBER de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III (ISCIII), Madrid, 28029, Spain; Instituto de Genética Médica y Molecular (INGEMM)-IdiPAZ, Hospital Universitario La Paz, Universidad Autónoma, Madrid, 28046, Spain; ITHACA, European Reference Network on Rare Congenital Malformations and Rare Intellectual Disability.
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11
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De Ridder R, Boudin E, Ibrahim J, Zillikens MC, van der Eerden BC, Van Hul W, Mortier G. Gene set enrichment analysis reveals a first somatic mutation in the catalytic domain of MAP2K1 in a melorheostosis patient. Bone Rep 2020. [DOI: 10.1016/j.bonr.2020.100357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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12
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Huybrechts Y, Steenackers E, Hamdy N, Mortier G, Martinez G, Bracamonte MS, Appelman-Dijkstra N, Van Hul W, Boudin E. Compound heterozygosity of mutations located in the first and third β-propeller domain of LRP4 causes sclerosteosis in a Spanish patient. Bone Rep 2020. [DOI: 10.1016/j.bonr.2020.100604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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13
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Peeters S, Decramer A, Cain SA, Houpt P, Verstreken F, Noyez J, Hermans C, Jacobs W, Lammens M, Fransen E, Kumar AA, Vandeweyer G, Loeys B, Van Hul W, Baldock C, Boudin E, Mortier G. Delineation of a new fibrillino-2-pathy with evidence for a role of FBN2 in the pathogenesis of carpal tunnel syndrome. J Med Genet 2020; 58:778-782. [PMID: 32900841 DOI: 10.1136/jmedgenet-2020-107085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/08/2020] [Accepted: 07/26/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Although carpal tunnel syndrome (CTS) is the most common form of peripheral entrapment neuropathy, its pathogenesis remains largely unknown. An estimated heritability index of 0.46 and an increased familial occurrence indicate that genetic factors must play a role in the pathogenesis. METHODS AND RESULTS We report on a family in which CTS occurred in subsequent generations at an unusually young age. Additional clinical features included brachydactyly and short Achilles tendons resulting in toe walking in childhood. Using exome sequencing, we identified a heterozygous variant (c.5009T>G; p.Phe1670Cys) in the fibrillin-2 (FBN2) gene that co-segregated with the phenotype in the family. Functional assays showed that the missense variant impaired integrin-mediated cell adhesion and migration. Moreover, we observed an increased transforming growth factor-β signalling and fibrosis in the carpal tissues of affected individuals. A variant burden test in a large cohort of patients with CTS revealed a significantly increased frequency of rare (6.7% vs 2.5%-3.4%, p<0.001) and high-impact (6.9% vs 2.7%, p<0.001) FBN2 variants in patient alleles compared with controls. CONCLUSION The identification of a novel FBN2 variant (p.Phe1670Cys) in a unique family with early onset CTS, together with the observed increased frequency of rare and high-impact FBN2 variants in patients with sporadic CTS, strongly suggest a role of FBN2 in the pathogenesis of CTS.
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Affiliation(s)
- Silke Peeters
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
| | - Arne Decramer
- Department of Orthopaedics and Traumatology, AZ Delta, Roeselare, Belgium
| | - Stuart Alan Cain
- Division of Cell-Matrix Biology and Regenerative Medicine, Wellcome Centre for Cell-Matrix Research, The University of Manchester, Manchester, UK
| | - Peter Houpt
- Department of Plastic Surgery, Isala Clinic Zwolle, Zwolle, The Netherlands
| | | | - Jan Noyez
- Department of Orthopaedics and Traumatology, AZ Delta, Roeselare, Belgium
| | - Christophe Hermans
- Center for Oncological Research Antwerp (CORE), University of Antwerp, Edegem, Belgium
| | - Werner Jacobs
- Department of Forensic Medicine and Pathology, Antwerp University Hospital and University of Antwerp, Edegem, Belgium
| | - Martin Lammens
- Department of Pathological Anatomy, Antwerp University Hospital, Edegem, Belgium
| | - Erik Fransen
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
| | - Ajay Anand Kumar
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
- Department of Paediatrics, Wellcome-MRC Cambridge Stem Cell Institute Cambridge, Cambridge University, Cambridge, UK
| | - Geert Vandeweyer
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
- Biomedical Informatics Research Network Antwerp (Biomina), University of Antwerp, Edegem, Belgium
| | - Bart Loeys
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
| | - Clair Baldock
- Division of Cell-Matrix Biology and Regenerative Medicine, Wellcome Centre for Cell-Matrix Research, The University of Manchester, Manchester, UK
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Edegem, Belgium
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14
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De Ridder R, Boudin E, Zillikens MC, Ibrahim J, van der Eerden BCJ, Van Hul W, Mortier G. A multi-omics approach expands the mutational spectrum of MAP2K1-related melorheostosis. Bone 2020; 137:115406. [PMID: 32387835 DOI: 10.1016/j.bone.2020.115406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 04/26/2020] [Accepted: 05/03/2020] [Indexed: 12/17/2022]
Abstract
Melorheostosis is a very rare sclerosing bone dysplasia characterized by asymmetrical and progressive cortical hyperostosis, usually with involvement of soft tissues surrounding the lesions. Recently Kang et al. identified somatic mosaicism for variants (p.Gln56Pro, p.Lys57Asn, or p.Lys57Glu) in the negative regulatory domain of MAP2K1, resulting in increased ERK1/2 signalling in affected tissues. In our study, we employed several sequencing technologies to unravel genetic variants (only present in affected tissues) from four sporadic melorheostosis patients. In the exome of two patients, we identified the same variants (p.K57N and p.K57E) as previously described by Kang et al. WGS and RNAseq analysis in a third patient demonstrated the presence of a novel variant (p.Cys121Ser) in the catalytic domain of MAP2K1. In addition, gene set enrichment analysis of the transcriptome data demonstrated upregulation of proliferative pathways. Interestingly, increased proliferation of MAP2K1 p.Lys57Asn-positive osteoblasts has been reported by Kang et al. The variants located in the hotspot region of the negative regulatory domain as well as this newly identified p.Cys121Ser variant have all been classified as MAP2K1 variants that can constitutively activate the downstream effector Erk. Finally, in a fourth patient with classical radiographic features of melorheostosis, no pathogenic variants could be identified in MAP2K1 or the other candidate genes for melorheostosis (SMAD3; LEMD3; KRAS). In conclusion, our study strongly suggests that not only somatic variants in the regulatory domain of MAP2K1 but also in the catalytic domain can cause melorheostosis. Our observations confirm that mutations in MAP2K1 are a major cause of melorheostosis and also suggest further locus heterogeneity for this disorder.
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Affiliation(s)
- Raphaël De Ridder
- Center of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Center of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - M Carola Zillikens
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Joe Ibrahim
- Center of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Bram C J van der Eerden
- Division of Endocrinology, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, the Netherlands
| | - Wim Van Hul
- Center of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Center of Medical Genetics, Antwerp University Hospital and University of Antwerp, Antwerp, Belgium.
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15
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Lauffer P, Miranda-Laferte E, van Duyvenvoorde HA, van Haeringen A, Werner F, Boudin E, Schmidt H, Mueller TD, Kuhn M, van der Kaay DCM. An Activating Deletion Variant in the Submembrane Region of Natriuretic Peptide Receptor-B Causes Tall Stature. J Clin Endocrinol Metab 2020; 105:5819532. [PMID: 32282051 PMCID: PMC7450217 DOI: 10.1210/clinem/dgaa190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/10/2020] [Indexed: 12/30/2022]
Abstract
CONTEXT C-type natriuretic peptide (CNP) is critically involved in endochondral bone growth. Variants in the genes encoding CNP or its cyclic guanosine monophosphate (cGMP)-forming receptor (natriuretic peptide receptor-B [NPR-B], gene NPR2) cause monogenic growth disorders. Here we describe a novel gain-of-function variant of NPR-B associated with tall stature and macrodactyly of the great toes (epiphyseal chondrodysplasia, Miura type). DESIGN History and clinical characteristics of 3 family members were collected. NPR2 was selected for sequencing. Skin fibroblasts and transfected HEK-293 cells were used to compare mutant versus wild-type NPR-B activities. Homology modeling was applied to understand the molecular consequences of the variant. RESULTS Mother's height was +2.77 standard deviation scores (SDS). The heights of her 2 daughters were +1.96 SDS at 7 years and +1.30 SDS at 4 years of age. Skeletal surveys showed macrodactyly of the great toes and pseudo-epiphyses of the mid- and proximal phalanges. Sequencing identified a novel heterozygous variant c.1444_1449delATGCTG in exon 8 of NPR2, predicted to result in deletion of 2 amino acids Met482-Leu483 within the submembrane region of NPR-B. In proband's skin fibroblasts, basal cGMP levels and CNP-stimulated cGMP production were markedly increased compared with controls. Consistently, assays with transfected HEK-293 cells showed markedly augmented baseline and ligand-dependent activity of mutant NPR-B. CONCLUSIONS We report the second activating variant within the intracellular submembrane region of NPR-B resulting in tall stature and macrodactyly. Our functional and modeling studies suggest that this domain plays a critical role in the baseline conformation and ligand-dependent structural rearrangement of NPR-B required for cGMP production.
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Affiliation(s)
- Peter Lauffer
- Department of Clinical Genetics, Leiden University Medical Center, ZA Leiden, the Netherlands
- Department of Paediatric Endocrinology, Emma Children’s Hospital, Amsterdam University Medical Center, AZ Amsterdam, the Netherlands
- Correspondence and Reprint Requests: Peter Lauffer, Emma Children’s Hospital, Amsterdam University Medical Center, Department of Paediatric Endocrinology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands. E-mail:
| | | | | | - Arie van Haeringen
- Department of Clinical Genetics, Leiden University Medical Center, ZA Leiden, the Netherlands
| | - Franziska Werner
- Institute of Physiology, University of Würzburg, Würzburg, Germany
| | - Eveline Boudin
- Centre of Medical Genetics, University of Antwerp, Edegem, Belgium
| | - Hannes Schmidt
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Thomas D Mueller
- Department of Molecular Plant Physiology and Biophysics, Julius-von-Sachs-Institute, Biocenter, University of Würzburg, Würzburg, Germany
| | - Michaela Kuhn
- Institute of Physiology, University of Würzburg, Würzburg, Germany
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Hendrickx G, Boudin E, Verbeek M, Fransen E, Mortier G, Van Hul W. WNT16 Requires Gα Subunits as Intracellular Partners for Both Its Canonical and Non-Canonical WNT Signalling Activity in Osteoblasts. Calcif Tissue Int 2020; 106:294-302. [PMID: 31760436 DOI: 10.1007/s00223-019-00633-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/11/2019] [Indexed: 01/08/2023]
Abstract
In the past years, WNT16 became an interesting target in the field of skeletal research, as it was identified as an essential regulator of the cortical bone compartment, with the ability to increase both cortical and trabecular bone mass and strength in vivo. Even though there are indications that these advantageous effects are coming from canonical and non-canonical WNT-signalling activity, a clear model of WNT signalling by WNT16 is not yet depicted. We, therefore, investigated the modulation of canonical (WNT/β-catenin) and non-canonical [WNT/calcium, WNT/planar cell polarity (PCP)] signalling in human embryonic kidney (HEK) 293 T and SaOS2 cells. Here, we demonstrated that WNT16 activates all WNT-signalling pathways in osteoblasts, whereas only WNT/calcium signalling was activated in HEK293T cells. In osteoblasts, we therefore, additionally investigated the role of Gα subunits as intracellular partners in WNT16's mechanism of action by performing knockdown of Gα12, Gα13 and Gαq. These studies point out that the above-mentioned Gα subunits might be involved in the WNT/β-catenin and WNT/calcium-signalling activity by WNT16 in osteoblasts, and for Gα12 in its WNT/PCP-signalling activity, illustrating a novel possible mechanism of interplay between the different WNT-signalling pathways in osteoblasts. Additional studies are needed to demonstrate whether this mechanism is specific for WNT16 signalling or relevant for all other WNT ligands as well. Altogether, we further defined WNT16's mechanism of action in osteoblasts that might underlie the well-known beneficial effects of WNT16 on skeletal homeostasis. These findings on WNT16 and the activity of specific Gα subunits in osteoblasts could definitely contribute to the development of novel therapeutic approaches for fragility fractures in the future.
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Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Marinus Verbeek
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Erik Fransen
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium.
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17
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Abstract
Skeletal dysplasias are a diverse group of heritable diseases affecting bone and cartilage growth. Throughout the years, the molecular defect underlying many of the diseases has been identified. These identifications led to novel insights in the mechanisms regulating bone and cartilage growth and homeostasis. One of the pathways that is clearly important during skeletal development and bone homeostasis is the Wingless and int-1 (WNT) signaling pathway. So far, three different WNT signaling pathways have been described, which are all activated by binding of the WNT ligands to the Frizzled (FZD) receptors. In this review, we discuss the skeletal disorders that are included in the latest nosology of skeletal disorders and that are caused by genetic defects involving the WNT signaling pathway. The number of skeletal disorders caused by defects in WNT signaling genes and the clinical phenotype associated with these disorders illustrate the importance of the WNT signaling pathway during skeletal development as well as later on in life to maintain bone mass. The knowledge gained through the identification of the genes underlying these monogenic conditions is used for the identification of novel therapeutic targets. For example, the genes underlying disorders with altered bone mass are all involved in the canonical WNT signaling pathway. Consequently, targeting this pathway is one of the major strategies to increase bone mass in patients with osteoporosis. In addition to increasing the insights in the pathways regulating skeletal development and bone homeostasis, knowledge of rare skeletal dysplasias can also be used to predict possible adverse effects of these novel drug targets. Therefore, this review gives an overview of the skeletal and extra-skeletal phenotype of the different skeletal disorders linked to the WNT signaling pathway.
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18
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Peeters JJM, De Ridder R, Hamoen EC, Eekhoff EMW, Smit F, Boudin E, Van Hul W, Papapoulos SE, Appelman-Dijkstra NM. Familial Paget's disease of bone: Long-term follow-up of unaffected relatives with and without Sequestosome 1 mutations. Bone 2019; 128:115044. [PMID: 31449886 DOI: 10.1016/j.bone.2019.115044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/09/2019] [Accepted: 08/21/2019] [Indexed: 01/05/2023]
Abstract
OBJECTIVE Familial Paget's disease of bone is inherited as an autosomal-dominant trait and mutations in the sequestosome 1 (SQSTM1) gene have been reported with variable frequency in patients with familial disease. The natural history, however, of the disease in family members with or without SQSTM1 mutations is unknown. METHODS To address this question, we investigated members of families with Paget's disease identified and genotyped in 2000 in The Netherlands without clinical, biochemical or radiological signs of Paget's disease. Seventy-five subjects, median age 56 years (range 44-93), with or without SQSTM1 mutations participated in the present study. Medical history was obtained and clinical examination and laboratory investigations were performed in all. When serum biochemical markers of bone turnover were increased, skeletal scintigraphy with SPECT-CT was performed. RESULTS After a mean period of 15.9 ± 0.32 (SD) years no subject without SQSTM1 mutations (either from positive or negative families) developed Paget's disease. Of 14 carriers of SQSTM1 mutations, Paget's disease of the pelvis was diagnosed in a 74-year old asymptomatic woman. CONCLUSION The incidence of new Paget's disease in SQSTM1 positive subjects was 7.1% and no mutation-negative subject developed the disease within 16 years of follow-up. Subjects without SQSTM1 mutations can be reassured whereas mutation carriers should consider screening. Our findings should be confirmed in other populations as currently unknown environmental factors that might be involved in the development of the disease may differ.
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Affiliation(s)
| | - Raphaël De Ridder
- Center of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Esther C Hamoen
- Department of Internal Medicine: Division of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands
| | - E Marelise W Eekhoff
- Department of Internal Medicine: Section Endocrinology, VU University Medical Center, Amsterdam, the Netherlands
| | - Frits Smit
- Department of Radiology, Leiden University Medical Center, Leiden, the Netherlands
| | - Eveline Boudin
- Center of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | | | - Natasha M Appelman-Dijkstra
- Center for Bone Quality, Leiden University Medical Center, Leiden, the Netherlands; Department of Internal Medicine: Division of Endocrinology, Leiden University Medical Center, Leiden, the Netherlands
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19
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De Ridder R, Boudin E, Vandeweyer G, Devogelaer JP, Fransen E, Mortier G, Van Hul W. Genetic Variation in RIN3 in the Belgian Population Supports Its Involvement in the Pathogenesis of Paget's Disease of Bone and Modifies the Age of Onset. Calcif Tissue Int 2019; 104:613-621. [PMID: 30726512 DOI: 10.1007/s00223-019-00530-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/28/2019] [Indexed: 12/24/2022]
Abstract
Paget's disease of bone (PDB) is a common, late-onset bone disorder characterized by focal increase of bone turnover. Mutations in the SQSTM1 gene are found in up to 40% of patients and recent GWAS have led to novel associations with several loci. RIN3, the candidate gene located at the associated 14q32 locus, has recently been studied in a British cohort to elucidate its contribution to the pathogenesis. In this study, we performed a genetic screening of RIN3 in an unrelated cohort to validate these findings and to further explore genetic variation in this gene in the context of PDB. In our screening, we examined the 5' untranslated region (UTR), the exonic regions and the intron-exon boundaries of the gene in a control cohort and a patient cohort. Our findings show clustering of variation similar to the British cohort and support a protective role for common genetic variation (rs117068593, p.R279C) in the proline-rich region and a functionally relevant role for rare genetic variation in the domains that mediate binding and activation of its interaction partner, Rab5. Additive regression models, fitted for the common variants, validated the association of the rs117068593 variant with the disease (OR+/+ 0.315; OR+/- 0.562). In addition, our analyses revealed a potentially modifying effect of this variant on the age of onset of the disease. In conclusion, our findings support the involvement of genetic variation in RIN3 in PDB and suggest a role for RIN3 as a potential modifier of the age of onset of the disease.
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Affiliation(s)
- Raphaël De Ridder
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium
| | - Eveline Boudin
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium
| | - Geert Vandeweyer
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium
| | - Jean-Pierre Devogelaer
- Department of Rheumatology, Saint-Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium
| | - Erik Fransen
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium
| | - Geert Mortier
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp & Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem, 2650, Antwerp, Belgium.
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20
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Abstract
Camurati-Engelmann disease or progressive diaphyseal dysplasia is a rare autosomal dominant sclerosing bone dysplasia. Mainly the skull and the diaphyses of the long tubular bones are affected. Clinically, the patients suffer from bone pain, easy fatigability, and decreased muscle mass and weakness in the proximal parts of the lower limbs resulting in gait disturbances. The disease-causing mutations are located within the TGFβ-1 gene and expected to or thought to disrupt the binding between TGFβ1 and its latency-associated peptide resulting in an increased signaling of the pathway and subsequently accelerated bone turnover. In preclinical studies, it was shown that targeting the type I receptor ameliorates the high bone turnover. In patients, treatment options are currently mostly limited to corticosteroids that may relieve the pain, and improve the muscle weakness and fatigue. In this review, the clinical and radiological characteristics as well as the molecular genetics of this condition are discussed.
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Affiliation(s)
- Wim Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, 2650, Edegem, Belgium.
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Filip M Vanhoenacker
- AZ Sint-Maarten, Antwerp University Hospital and Ghent University, Mechelen, Belgium
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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21
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Abstract
The group of sclerosing bone dysplasia's is a clinically and genetically heterogeneous group of rare bone disorders which, according to the latest Nosology and classification of genetic skeletal disorders (2015), can be subdivided in three subgroups; the neonatal osteosclerotic dysplasias, the osteopetroses and related disorders and the other sclerosing bone disorders. Here, we give an overview of the most important radiographic and clinical symptoms, the underlying genetic defect and potential treatment options of the different sclerosing dysplasias included in these subgroups.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium.
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22
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Boudin E, de Jong TR, Prickett TCR, Lapauw B, Toye K, Van Hoof V, Luyckx I, Verstraeten A, Heymans HSA, Dulfer E, Van Laer L, Berry IR, Dobbie A, Blair E, Loeys B, Espiner EA, Wit JM, Van Hul W, Houpt P, Mortier GR. Bi-allelic Loss-of-Function Mutations in the NPR-C Receptor Result in Enhanced Growth and Connective Tissue Abnormalities. Am J Hum Genet 2018; 103:288-295. [PMID: 30032985 DOI: 10.1016/j.ajhg.2018.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 06/12/2018] [Indexed: 12/20/2022] Open
Abstract
The natriuretic peptide signaling pathway has been implicated in many cellular processes, including endochondral ossification and bone growth. More precisely, different mutations in the NPR-B receptor and the CNP ligand have been identified in individuals with either short or tall stature. In this study we show that the NPR-C receptor (encoded by NPR3) is also important for the regulation of linear bone growth. We report four individuals, originating from three different families, with a phenotype characterized by tall stature, long digits, and extra epiphyses in the hands and feet. In addition, aortic dilatation was observed in two of these families. In each affected individual, we identified a bi-allelic loss-of-function mutation in NPR3. The missense mutations (c.442T>C [p.Ser148Pro] and c.1088A>T [p.Asp363Val]) resulted in intracellular retention of the NPR-C receptor and absent localization on the plasma membrane, whereas the nonsense mutation (c.1524delC [p.Tyr508∗]) resulted in nonsense-mediated mRNA decay. Biochemical analysis of plasma from two affected and unrelated individuals revealed a reduced NTproNP/NP ratio for all ligands and also high cGMP levels. These data strongly suggest a reduced clearance of natriuretic peptides by the defective NPR-C receptor and consequently increased activity of the NPR-A/B receptors. In conclusion, this study demonstrates that loss-of-function mutations in NPR3 result in increased NPR-A/B signaling activity and cause a phenotype marked by enhanced bone growth and cardiovascular abnormalities.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Tjeerd R de Jong
- Department of Plastic and Reconstructive Surgery and Hand Surgery, Isala Clinics, 8025 AB Zwolle, the Netherlands
| | - Tim C R Prickett
- Department of Medicine, University of Otago, Christchurch 8011, New Zealand
| | - Bruno Lapauw
- Department of Endocrinology and Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - Kaatje Toye
- Department of Endocrinology and Unit for Osteoporosis and Metabolic Bone Diseases, Ghent University Hospital, 9000 Ghent, Belgium
| | - Viviane Van Hoof
- Department of Clinical Chemistry, Antwerp University Hospital, 2650 Edegem, Belgium
| | - Ilse Luyckx
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Aline Verstraeten
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Hugo S A Heymans
- Department of Pediatrics, Emma's Children's Hospital - Academic Medical Centre, 1105 AZ Amsterdam, the Netherlands
| | - Eelco Dulfer
- Department of Medical Genetics, University Medical Center Groningen, 9713 GZ Groningen, the Netherlands
| | - Lut Van Laer
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Ian R Berry
- Leeds Genetics Laboratory, St James's University Hospital, Leeds LS7 4SA, UK
| | - Angus Dobbie
- Yorkshire Clinical Genetics Service, Chapel Allerton Hospital, Leeds LS7 4SA, UK
| | - Ed Blair
- Oxford Centre for Genomic Medicine, Oxford University Hospitals NHS Foundation Trust, Oxford OX3 7HE, UK
| | - Bart Loeys
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Eric A Espiner
- Department of Medicine, University of Otago, Christchurch 8011, New Zealand
| | - Jan M Wit
- Department of Pediatrics, Leiden University Medical Center, 2333 ZA Leiden, the Netherlands
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium
| | - Peter Houpt
- Department of Plastic and Reconstructive Surgery and Hand Surgery, Isala Clinics, 8025 AB Zwolle, the Netherlands
| | - Geert R Mortier
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, 2650 Edegem, Belgium.
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23
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Abstract
PURPOSE OF REVIEW The group of sclerosing bone disorders encompasses a variety of disorders all marked by increased bone mass. In this review, we give an overview of the genetic causes of this heterogeneous group of disorders and briefly touch upon the value of these findings for the development of novel therapeutic agents. RECENT FINDINGS Advances in the next-generation sequencing technologies are accelerating the molecular dissection of the pathogenic mechanisms underlying skeletal dysplasias. Throughout the years, the genetic cause of these disorders has been extensively studied which resulted in the identification of a variety of disease-causing genes and pathways that are involved in bone formation by osteoblasts, bone resorption by osteoclasts, or both processes. Due to this rapidly increasing knowledge, the insights into the regulatory mechanisms of bone metabolism are continuously improving resulting in the identification of novel therapeutic targets for disorders with reduced bone mass and increased bone fragility.
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Affiliation(s)
- Raphaël De Ridder
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Centre of Medical Genetics, University of Antwerp & University Hospital Antwerp, Antwerp, Belgium.
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24
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Hendrickx G, Borra VM, Steenackers E, Yorgan TA, Hermans C, Boudin E, Waterval JJ, Jansen IDC, Aydemir TB, Kamerling N, Behets GJ, Plumeyer C, D’Haese PC, Busse B, Everts V, Lammens M, Mortier G, Cousins RJ, Schinke T, Stokroos RJ, Manni JJ, Van Hul W. Conditional mouse models support the role of SLC39A14 (ZIP14) in Hyperostosis Cranialis Interna and in bone homeostasis. PLoS Genet 2018; 14:e1007321. [PMID: 29621230 PMCID: PMC5903675 DOI: 10.1371/journal.pgen.1007321] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 04/17/2018] [Accepted: 03/19/2018] [Indexed: 01/19/2023] Open
Abstract
Hyperostosis Cranialis Interna (HCI) is a rare bone disorder characterized by progressive intracranial bone overgrowth at the skull. Here we identified by whole-exome sequencing a dominant mutation (L441R) in SLC39A14 (ZIP14). We show that L441R ZIP14 is no longer trafficked towards the plasma membrane and excessively accumulates intracellular zinc, resulting in hyper-activation of cAMP-CREB and NFAT signaling. Conditional knock-in mice overexpressing L438R Zip14 in osteoblasts have a severe skeletal phenotype marked by a drastic increase in cortical thickness due to an enhanced endosteal bone formation, resembling the underlying pathology in HCI patients. Remarkably, L438R Zip14 also generates an osteoporotic trabecular bone phenotype. The effects of osteoblastic overexpression of L438R Zip14 therefore mimic the disparate actions of estrogen on cortical and trabecular bone through osteoblasts. Collectively, we reveal ZIP14 as a novel regulator of bone homeostasis, and that manipulating ZIP14 might be a therapeutic strategy for bone diseases.
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Affiliation(s)
- Gretl Hendrickx
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Vere M. Borra
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Ellen Steenackers
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Timur A. Yorgan
- Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christophe Hermans
- Center for Oncological Research Antwerp (CORE), University of Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Jérôme J. Waterval
- Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Ineke D. C. Jansen
- Department of Periodontology and Oral Cell Biology, Academic Center of Dentistry Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Tolunay Beker Aydemir
- Food Science and Human Nutrition Department and Center for Nutritional Sciences, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL, United States of America
| | - Niels Kamerling
- Department of Neurosurgery, University Hospital Antwerp, Antwerp, Belgium
| | - Geert J. Behets
- Department of Pathophysiology, University of Antwerp, Antwerp, Belgium
| | - Christine Plumeyer
- Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Björn Busse
- Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Vincent Everts
- Department of Periodontology and Oral Cell Biology, Academic Center of Dentistry Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Martin Lammens
- Department of Pathological Anatomy, University Hospital Antwerp, Antwerp, Belgium
| | - Geert Mortier
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
| | - Robert J. Cousins
- Food Science and Human Nutrition Department and Center for Nutritional Sciences, College of Agricultural and Life Sciences, University of Florida, Gainesville, FL, United States of America
| | - Thorsten Schinke
- Department of Osteology and Biomechanics (IOBM), University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Robert J. Stokroos
- Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Johannes J. Manni
- Department of Otorhinolaryngology and Head & Neck Surgery, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Wim Van Hul
- Center of Medical Genetics, University and University Hospital of Antwerp, Antwerp, Belgium
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25
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Boudin E, Yorgan T, Fijalkowski I, Sonntag S, Steenackers E, Hendrickx G, Peeters S, De Maré A, Vervaet B, Verhulst A, Mortier G, D'Haese P, Schinke T, Van Hul W. The Lrp4R1170Q Homozygous Knock-In Mouse Recapitulates the Bone Phenotype of Sclerosteosis in Humans. J Bone Miner Res 2017; 32:1739-1749. [PMID: 28477420 DOI: 10.1002/jbmr.3160] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 04/13/2017] [Accepted: 04/22/2017] [Indexed: 01/08/2023]
Abstract
Sclerosteosis is a rare autosomal recessive bone disorder marked by hyperostosis of the skull and tubular bones. Initially, we and others reported that sclerosteosis was caused by loss-of-function mutations in SOST, encoding sclerostin. More recently, we identified disease-causing mutations in LRP4, a binding partner of sclerostin, in three sclerosteosis patients. Upon binding to sclerostin, LRP4 can inhibit the canonical WNT signaling that is known to be an important pathway in the regulation of bone formation. To further investigate the role of LRP4 in the bone formation process, we generated an Lrp4 mutated sclerosteosis mouse model by introducing the p.Arg1170Gln mutation in the mouse genome. Extensive analysis of the bone phenotype of the Lrp4R1170Q/R1170Q knock-in (KI) mouse showed the presence of increased trabecular and cortical bone mass as a consequence of increased bone formation by the osteoblasts. In addition, three-point bending analysis also showed that the increased bone mass results in increased bone strength. In contrast to the human sclerosteosis phenotype, we could not observe syndactyly in the forelimbs or hindlimbs of the Lrp4 KI animals. Finally, we could not detect any significant changes in the bone formation and resorption markers in the serum of the mutant mice. However, the serum sclerostin levels were strongly increased and the level of sclerostin in the tibia was decreased in Lrp4R1170Q/R1170Q mice, confirming the role of LRP4 as an anchor for sclerostin in bone. In conclusion, the Lrp4R1170Q/R1170Q mouse is a good model for the human sclerosteosis phenotype caused by mutations in LRP4 and can be used in the future for further investigation of the mechanism whereby LRP4 regulates bone formation. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Timur Yorgan
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Igor Fijalkowski
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | | | - Ellen Steenackers
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Gretl Hendrickx
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Silke Peeters
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Annelies De Maré
- Laboratory of Pathophysiology, Department Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Benjamin Vervaet
- Laboratory of Pathophysiology, Department Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Anja Verhulst
- Laboratory of Pathophysiology, Department Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Geert Mortier
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Patrick D'Haese
- Laboratory of Pathophysiology, Department Biomedical Sciences, University of Antwerp, Wilrijk, Belgium
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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26
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Abstract
Throughout life, bone is continuously remodelled to be able to fulfil its multiple functions. The importance of strictly regulating the bone remodelling process, which is defined by the sequential actions of osteoclasts and osteoblasts, is shown by a variety of disorders with abnormalities in bone mass and strength. The best known and most common example of such a disorder is osteoporosis, which is marked by a decreased bone mass and strength that consequently results in an increased fracture risk. As osteoporosis is a serious health problem, a large number of studies focus on elucidating the aetiology of the disease as well as on the identification of novel therapeutic targets for the treatment of osteoporotic patients. These studies have demonstrated that a large amount of variation in bone mass and strength is often influenced by genetic variation in genes encoding important regulators of bone homeostasis. Throughout the years, studies into the genetic causes of osteoporosis as well as several rare monogenic disorders with abnormal high or low bone mass and strength have largely increased the knowledge on regulatory pathways important for bone resorption and formation. This review gives an overview of genes and pathways that are important for the regulation of bone formation and that are identified through their involvement in monogenic and complex disorders with abnormal bone mass. Furthermore, novel bone-forming strategies for the treatment of osteoporosis that resulted from these discoveries, such as antibodies against sclerostin, are discussed as well.
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Affiliation(s)
- Eveline Boudin
- Center of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp, Antwerp, Belgium
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27
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Hendrickx G, Boudin E, Steenackers E, Nielsen TL, Andersen M, Brixen K, Van Hul W. Genetic Screening of WNT4 and WNT5B in Two Populations with Deviating Bone Mineral Densities. Calcif Tissue Int 2017; 100:244-249. [PMID: 28078366 DOI: 10.1007/s00223-016-0213-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 11/08/2016] [Indexed: 10/20/2022]
Abstract
A role for WNT4 and WNT5B in bone metabolism was indicated by genome-wide association studies (GWAS) and a Wnt4 knockout mouse model. The aim of this study was therefore to replicate and further investigate the causality between genetic variation in WNT4 and WNT5B and deviating bone mineral density (BMD) values. A WNT4 and WNT5B mutation screening was performed in patients with craniotubular hyperostosis using Sanger sequencing. Here, no putative causal mutations were detected. Moreover, a high and low BMD cohort was selected from the Odense Androgen Study population for re-sequencing. In WNT4 we detected four variants (three rare, one common), while in WNT5B we detected five variants (two rare, three common). For the common variants, no significant difference in genotype frequencies between the high and low BMD cohorts was observed. The SNPs associated with the GWAS were genotyped in these cohorts, but again no significant difference in genotype frequencies was observed. Despite the findings of the GWAS, we were not able to replicate or further verify the genetic association of polymorphisms in WNT4 and WNT5B with BMD. In order to do so, the intronic regions of both genes could be investigated more thoroughly in more extended populations (or extremes) with greater power. Future genetic and functional studies toward adjacent genes of WNT4 and WNT5B can also be interesting to figure out whether the signal from GWAS could possibly be attributed to genetic variation in these genes.
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Affiliation(s)
- Gretl Hendrickx
- Center of Medical Genetics, University of Antwerp and University Hospital of Antwerp, Edegem, Belgium
| | - Eveline Boudin
- Center of Medical Genetics, University of Antwerp and University Hospital of Antwerp, Edegem, Belgium
| | - Ellen Steenackers
- Center of Medical Genetics, University of Antwerp and University Hospital of Antwerp, Edegem, Belgium
| | - Torben Leo Nielsen
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Marianne Andersen
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Kim Brixen
- Department of Endocrinology, Odense University Hospital, Odense, Denmark
| | - Wim Van Hul
- Center of Medical Genetics, University of Antwerp and University Hospital of Antwerp, Edegem, Belgium.
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Abstract
Bone mineral density (BMD) is a quantitative traits used as a surrogate phenotype for the diagnosis of osteoporosis, a common metabolic disorder characterized by increased fracture risk as a result of a decreased bone mass and deterioration of the microarchitecture of the bone. Normal variation in BMD is determined by both environmental and genetic factors. According to heritability studies, 50-85% of the variance in BMD is controlled by genetic factors which are mostly polygenic. In contrast to the complex etiology of osteoporosis, there are disorders with deviating BMD values caused by one mutation with a large impact. These mutations can result in monogenic bone disorders with either an extreme high (sclerosteosis, Van Buchem disease, osteopetrosis, high bone mass phenotype) or low BMD (osteogenesis imperfecta, juvenile osteoporosis, primary osteoporosis). Identification of the disease causing genes, increased the knowledge on the regulation of BMD and highlighted important signaling pathways and novel therapeutic targets such as sclerostin, RANKL and cathepsin K. Genetic variation in genes involved in these pathways are often also involved in the regulation of normal variation in BMD and osteoporosis susceptibility. In the last decades, identification of genetic factors regulating BMD has proven to be a challenge. Several approaches have been tested such as linkage studies and candidate and genome wide association studies. Although, throughout the years, technological developments made it possible to study increasing numbers of genetic variants in populations with increasing sample sizes at the same time, only a small fraction of the genetic impact can yet be explained. In order to elucidate the missing heritability, the focus shifted to studying the role of rare variants, copy number variations and epigenetic influences. This review summarizes the genetic cause of different monogenic bone disorders with deviating BMD and the knowledge on genetic factors explaining normal variation in BMD and osteoporosis risk.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Igor Fijalkowski
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium.
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29
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Fijalkowski I, Geets E, Steenackers E, Van Hoof V, Ramos FJ, Mortier G, Fortuna AM, Van Hul W, Boudin E. A Novel Domain-Specific Mutation in a Sclerosteosis Patient Suggests a Role of LRP4 as an Anchor for Sclerostin in Human Bone. J Bone Miner Res 2016; 31:874-81. [PMID: 26751728 DOI: 10.1002/jbmr.2782] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 01/04/2016] [Accepted: 01/07/2016] [Indexed: 12/22/2022]
Abstract
Mutations in the LRP4 gene, coding for a Wnt signaling coreceptor, have been found to cause several allelic conditions. Among these, two are characterized by a strong skeletal involvement, namely sclerosteosis and Cenani-Lenz syndrome. In this work, we evaluated the role of LRP4 in the pathophysiology of these diseases. First, we report a novel LRP4 mutation, leading to the substitution of arginine at position 1170 in glutamine, identified in a patient with sclerosteosis. This mutation is located in the central cavity of the third β-propeller domain, which is in line with two other sclerosteosis mutations we previously described. Reporter assays demonstrate that this mutation leads to impaired sclerostin inhibition of Wnt signaling. Moreover, we compared the effect of this novel variant to mutations causing Cenani-Lenz syndrome and show that impaired membrane trafficking of the LRP4 protein is the likely mechanism underlying Cenani-Lenz syndrome. This is in contrast to sclerosteosis mutations, previously shown to impair the binding between LRP4 and sclerostin. In addition, to better understand the biology of LRP4, we investigated the circulating sclerostin levels in the serum of a patient suffering from sclerosteosis owing to a LRP4 mutation. We demonstrate that impaired sclerostin binding to the mutated LRP4 protein leads to dramatic increase in circulating sclerostin in this patient. With this study, we provide the first evidence suggesting that LRP4 is responsible for the retention of sclerostin in the bone environment in humans. These findings raise potential concerns about the utility of determining circulating sclerostin levels as a marker for other bone-related parameters. Although more studies are needed to fully understand the mechanism whereby LRP4 facilitates sclerostin action, it is clear that this protein represents a potent target for future osteoporosis therapies and an interesting alternative for the antisclerostin treatment currently under study.
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Affiliation(s)
- Igor Fijalkowski
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Ellen Geets
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Ellen Steenackers
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Viviane Van Hoof
- Department of Clinical Chemistry, Antwerp University Hospital, Antwerp, Belgium
| | - Feliciano J Ramos
- Unidad de Genética, Servicio de Pediatria, Hospital Clinico Universitario "Lozano Blesa", GCV-CIBERER, Facultad de Medicina, Universidad de Zaragoza, Zaragoza, Spain
| | - Geert Mortier
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Ana Maria Fortuna
- Centro de Genética Médica, Centro Hospitalar do Porto, and Unit for Multidisciplinary Research in Biomedicine, UMIB, ICBAS-UP,, Porto, Portugal
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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30
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Palagano E, Blair HC, Pangrazio A, Tourkova I, Strina D, Angius A, Cuccuru G, Oppo M, Uva P, Van Hul W, Boudin E, Superti-Furga A, Faletra F, Nocerino A, Ferrari MC, Grappiolo G, Monari M, Montanelli A, Vezzoni P, Villa A, Sobacchi C. Buried in the Middle but Guilty: Intronic Mutations in the TCIRG1 Gene Cause Human Autosomal Recessive Osteopetrosis. J Bone Miner Res 2015; 30:1814-21. [PMID: 25829125 DOI: 10.1002/jbmr.2517] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 03/16/2015] [Accepted: 03/22/2015] [Indexed: 11/10/2022]
Abstract
Autosomal recessive osteopetrosis (ARO) is a rare genetic bone disease with genotypic and phenotypic heterogeneity, sometimes translating into delayed diagnosis and treatment. In particular, cases of intermediate severity often constitute a diagnostic challenge and represent good candidates for exome sequencing. Here, we describe the tortuous path to identification of the molecular defect in two siblings, in which osteopetrosis diagnosed in early childhood followed a milder course, allowing them to reach the adult age in relatively good conditions with no specific therapy. No clearly pathogenic mutation was identified either with standard amplification and resequencing protocols or with exome sequencing analysis. While evaluating the possible impact of a 3'UTR variant on the TCIRG1 expression, we found a novel single nucleotide change buried in the middle of intron 15 of the TCIRG1 gene, about 150 nucleotides away from the closest canonical splice site. By sequencing a number of independent cDNA clones covering exons 14 to 17, we demonstrated that this mutation reduced splicing efficiency but did not completely abrogate the production of the normal transcript. Prompted by this finding, we sequenced the same genomic region in 33 patients from our unresolved ARO cohort and found three additional novel single nucleotide changes in a similar location and with a predicted disruptive effect on splicing, further confirmed in one of them at the transcript level. Overall, we identified an intronic region in TCIRG1 that seems to be particularly prone to splicing mutations, allowing the production of a small amount of protein sufficient to reduce the severity of the phenotype usually associated with TCIRG1 defects. On this basis, we would recommend including TCIRG1 not only in the molecular work-up of severe infantile osteopetrosis but also in intermediate cases and carefully evaluating the possible effects of intronic changes.
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Affiliation(s)
- Eleonora Palagano
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Harry C Blair
- Veteran's Affairs Medical Center and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Alessandra Pangrazio
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Irina Tourkova
- Veteran's Affairs Medical Center and Department of Pathology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Dario Strina
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Andrea Angius
- CRS4, Science and Technology Park Polaris, Piscina Manna, Pula, Italy.,Institute of Genetic and Biomedical Research (IRGB), National Research Council (CNR), Monserrato, Italy
| | - Gianmauro Cuccuru
- CRS4, Science and Technology Park Polaris, Piscina Manna, Pula, Italy
| | - Manuela Oppo
- CRS4, Science and Technology Park Polaris, Piscina Manna, Pula, Italy
| | - Paolo Uva
- CRS4, Science and Technology Park Polaris, Piscina Manna, Pula, Italy
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Antwerp, Belgium
| | - Andrea Superti-Furga
- Department of Pediatrics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Flavio Faletra
- Institute for Maternal and Child Health-IRCCS "Burlo Garofolo", Trieste, Italy
| | - Agostino Nocerino
- Clinica Pediatrica, Azienda Ospedaliero-Universitaria "S Maria della Misericordia", Udine, Italy
| | - Matteo C Ferrari
- Hip and Prosthetic Replacement Unit, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Guido Grappiolo
- Hip and Prosthetic Replacement Unit, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Marta Monari
- Clinical Investigation Laboratory, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Alessandro Montanelli
- Clinical Investigation Laboratory, Humanitas Clinical and Research Center, Rozzano, Italy
| | - Paolo Vezzoni
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Anna Villa
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
| | - Cristina Sobacchi
- UOS/IRGB, Milan Unit, National Research Council (CNR), Milan, Italy.,Humanitas Clinical and Research Center, Rozzano, Italy
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31
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Abstract
Osteoporosis is a common disorder, affecting hundreds of millions of people worldwide, and characterized by decreased bone mineral density and increased fracture risk. Known nonheritable risk factors for primary osteoporosis include advanced age, sex-steroid deficiency and increased oxidative stress. Age is a nonmodifiable risk factor, but the influence of a person's lifestyle (diet and physical activity) on their bone structure and density is modifiable to some extent. Heritable factors influencing bone fragility can be monogenic or polygenic. Osteogenesis imperfecta, juvenile osteoporosis and syndromes of decreased bone density are discussed as examples of monogenic disorders associated with bone fragility. So far, the factors associated with polygenic osteoporosis have been investigated mainly in genome-wide association studies. However, epigenetic mechanisms also contribute to the heritability of polygenic osteoporosis. Identification of these heritable and nonheritable risk factors has already led to the discovery of therapeutic targets for osteoporosis, which emphasizes the importance of research into the pathogenetic mechanisms of osteoporosis. Accordingly, this article discusses the many heritable and nonheritable factors that contribute to the pathogenesis of primary osteoporosis. Although osteoporosis can also develop secondary to many other diseases or their treatment, a discussion of the factors that contribute only to secondary osteoporosis is beyond the scope of this Review.
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Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43B, 2650 Edegem, Belgium
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32
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Huckert M, Stoetzel C, Morkmued S, Laugel-Haushalter V, Geoffroy V, Muller J, Clauss F, Prasad MK, Obry F, Raymond JL, Switala M, Alembik Y, Soskin S, Mathieu E, Hemmerlé J, Weickert JL, Dabovic BB, Rifkin DB, Dheedene A, Boudin E, Caluseriu O, Cholette MC, Mcleod R, Antequera R, Gellé MP, Coeuriot JL, Jacquelin LF, Bailleul-Forestier I, Manière MC, Van Hul W, Bertola D, Dollé P, Verloes A, Mortier G, Dollfus H, Bloch-Zupan A. Mutations in the latent TGF-beta binding protein 3 (LTBP3) gene cause brachyolmia with amelogenesis imperfecta. Hum Mol Genet 2015; 24:3038-49. [PMID: 25669657 PMCID: PMC4424950 DOI: 10.1093/hmg/ddv053] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2014] [Accepted: 02/06/2015] [Indexed: 01/27/2023] Open
Abstract
Inherited dental malformations constitute a clinically and genetically heterogeneous group of disorders. Here, we report on four families, three of them consanguineous, with an identical phenotype, characterized by significant short stature with brachyolmia and hypoplastic amelogenesis imperfecta (AI) with almost absent enamel. This phenotype was first described in 1996 by Verloes et al. as an autosomal recessive form of brachyolmia associated with AI. Whole-exome sequencing resulted in the identification of recessive hypomorphic mutations including deletion, nonsense and splice mutations, in the LTBP3 gene, which is involved in the TGF-beta signaling pathway. We further investigated gene expression during mouse development and tooth formation. Differentiated ameloblasts synthesizing enamel matrix proteins and odontoblasts expressed the gene. Study of an available knockout mouse model showed that the mutant mice displayed very thin to absent enamel in both incisors and molars, hereby recapitulating the AI phenotype in the human disorder.
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Affiliation(s)
- Mathilde Huckert
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Reference Centre for Orodental Manifestations of Rare Diseases, CRMR, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Corinne Stoetzel
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France
| | - Supawich Morkmued
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CERBM, INSERM U 964, CNRS UMR 7104, 1 rue Laurent Fries, BP 10142, Illkirch 67404, France Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Virginie Laugel-Haushalter
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CERBM, INSERM U 964, CNRS UMR 7104, 1 rue Laurent Fries, BP 10142, Illkirch 67404, France
| | - Véronique Geoffroy
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France
| | - Jean Muller
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CERBM, INSERM U 964, CNRS UMR 7104, 1 rue Laurent Fries, BP 10142, Illkirch 67404, France Université de Strasbourg, Laboratoire ICube UMR 7357, CNRS, LBGI, Strasbourg, France Hôpitaux Universitaires de Strasbourg, Laboratoire de Diagnostic Génétique, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - François Clauss
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Université de Strasbourg, Osteoarticular and Dental Regenerative NanoMedicine, Inserm UMR 1109, 11 rue Humann 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Reference Centre for Orodental Manifestations of Rare Diseases, CRMR, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Megana K Prasad
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France
| | - Frédéric Obry
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Reference Centre for Orodental Manifestations of Rare Diseases, CRMR, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Jean Louis Raymond
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France
| | - Marzena Switala
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Reference Centre for Orodental Manifestations of Rare Diseases, CRMR, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Yves Alembik
- Hôpitaux Universitaires de Strasbourg, Service de Génétique Médicale, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Sylvie Soskin
- Hôpitaux Universitaires de Strasbourg, Service de Pédiatrie 1, Endocrinologie Pédiatrique, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Eric Mathieu
- Université de Strasbourg, Biomaterials and Bioengineering, Inserm UMR 1121, 11 rue Humann, 67000 Strasbourg, France
| | - Joseph Hemmerlé
- Université de Strasbourg, Biomaterials and Bioengineering, Inserm UMR 1121, 11 rue Humann, 67000 Strasbourg, France
| | - Jean-Luc Weickert
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CERBM, INSERM U 964, CNRS UMR 7104, 1 rue Laurent Fries, BP 10142, Illkirch 67404, France
| | | | - Daniel B Rifkin
- Department of Cell Biology, NYU Langone Medical Centre, New York, USA
| | - Annelies Dheedene
- Center for Medical Genetics, Ghent University, Ghent University Hospital, De Pintelaan 185, Ghent 9000, Belgium
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem 2650, Belgium
| | - Oana Caluseriu
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | - Marie-Claude Cholette
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | - Ross Mcleod
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Calgary, Alberta Children's Hospital, Calgary, AB, Canada
| | | | - Marie-Paule Gellé
- Faculté d'Odontologie, Université de Reims Champagne-Ardenne, 2 rue du Général Koenig, Reims 51100, France Laboratoire EA 4691 'BIOS', 1, rue du Maréchal Juin, Reims 51100, France
| | - Jean-Louis Coeuriot
- Faculté d'Odontologie, Université de Reims Champagne-Ardenne, 2 rue du Général Koenig, Reims 51100, France
| | - Louis-Frédéric Jacquelin
- Faculté d'Odontologie, Université de Reims Champagne-Ardenne, 2 rue du Général Koenig, Reims 51100, France
| | - Isabelle Bailleul-Forestier
- Faculty of Dentistry, Paul Sabatier University, LU51, Pôle Odontologie, Hôpitaux de Toulouse, 3 Chemin des Maraîchers, Toulouse, France
| | - Marie-Cécile Manière
- Université de Strasbourg, Faculté de Chirurgie Dentaire, 8 rue St Elisabeth, 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Pôle de Médecine et Chirurgie Bucco-Dentaires, Reference Centre for Orodental Manifestations of Rare Diseases, CRMR, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem 2650, Belgium
| | - Debora Bertola
- Unidade de Genética do Instituto da Criança, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo - Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil and
| | - Pascal Dollé
- Université de Strasbourg, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CERBM, INSERM U 964, CNRS UMR 7104, 1 rue Laurent Fries, BP 10142, Illkirch 67404, France
| | - Alain Verloes
- Département de Génétique - Hôpital Robert Debré, CRMR 'Anomalies du Développement & Syndromes Malformatifs', CRMR 'Déficiences Intellectuelles de Causes Rares', 48 bd Sérurier, Paris 75019, France
| | - Geert Mortier
- Center for Medical Genetics, Ghent University, Ghent University Hospital, De Pintelaan 185, Ghent 9000, Belgium Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Prins Boudewijnlaan 43, Edegem 2650, Belgium
| | - Hélène Dollfus
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France Hôpitaux Universitaires de Strasbourg, Service de Génétique Médicale, 1 place de l'Hôpital, 67000 Strasbourg, France
| | - Agnès Bloch-Zupan
- Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France Université de Strasbourg, Laboratoire de Génétique Médicale, INSERM UMR 1112, Faculté de Médecine, FMTS, 11 rue Humann 67000 Strasbourg, France
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33
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Abstract
Sclerosing bone dysplasias are a group of rare, monogenic disorders characterized by increased bone density resulting from the disturbance in the fragile equilibrium between bone formation and resorption. Over the last decade, major contributions have been made toward better understanding of the pathogenesis of these conditions. These studies provided us with important insights into the bone biology and yielded the identification of numerous drug targets for the prevention and treatment of osteoporosis. Here, we review this heterogeneous group of disorders focusing on their utility in the development of novel osteoporosis therapies.
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Affiliation(s)
- Igor Fijalkowski
- Department of Medical Genetics, University and University Hospital of Antwerp, Edegem, Belgium
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34
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Hendrickx G, Boudin E, Fijałkowski I, Nielsen TL, Andersen M, Brixen K, Van Hul W. Variation in the Kozak sequence of WNT16 results in an increased translation and is associated with osteoporosis related parameters. Bone 2014; 59:57-65. [PMID: 24185276 DOI: 10.1016/j.bone.2013.10.022] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Revised: 10/24/2013] [Accepted: 10/25/2013] [Indexed: 11/28/2022]
Abstract
The importance of WNT16 in the regulation of bone metabolism was recently confirmed by several genome-wide association studies and by a Wnt16 (Wnt16(-/-)) knockout mouse model. The aim of this study was thus to replicate and further elucidate the effect of common genetic variation in WNT16 on osteoporosis related parameters. Hereto, we performed a WNT16 candidate gene association study in a population of healthy Caucasian men from the Odense Androgen Study (OAS). Using HapMap, five tagSNPs and one multimarker test were selected for genotyping to cover most of the common genetic variation in and around WNT16 (MAF>5%). This study confirmed previously reported associations for rs3801387 and rs2707466 with bone mineral density (BMD) at several sites. Furthermore, we additionally demonstrated that rs2908007 is strongly associated with BMD at several sites in the young, elderly and complete OAS population. The observed effect of these three associated SNPs on the respective phenotypes is comparable and we can conclude that the presence of the minor allele results in an increase in BMD. Additionally, we performed re-sequencing of WNT16 on two cohorts selected from the young OAS cohort, based on their extreme BMD values. On this basis, rs55710688 was selected for an in vitro translation experiment since it is located in the Kozak sequence of WNT16a. We observed an increased translation efficiency and thus a higher amount of WNT16a for the Kozak sequence that was significantly more prevalent in the high BMD cohort. This observation is in line with the results of the Wnt16(-/-) mice. Finally, a WNT luciferase reporter assay was performed and showed no activation of the β-catenin dependent pathway by Wnt16. We did detect a dose-dependent inhibitory effect of Wnt16 on WNT1 activation of this canonical WNT pathway. Increased translation of WNT16 can thus lead to an increased inhibitory action of WNT16 on canonical WNT signaling. This statement is in contrast with the known activating effect of canonical WNT signaling on bone formation and suggests a stimulatory effect on bone metabolism via noncanonical WNT signaling. More research is required to not only confirm this hypothesis, but also to further elucidate the role of non-canonical WNT pathways in bone metabolism and the general mechanisms of interplay between the different WNT signaling pathways.
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Affiliation(s)
- Gretl Hendrickx
- Department of Medical Genetics, University of Antwerp, Belgium.
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Belgium.
| | | | | | | | - Kim Brixen
- Department of Endocrinology, Odense University Hospital, Denmark.
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, Belgium.
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Boudin E, Fijalkowski I, Piters E, Van Hul W. The role of extracellular modulators of canonical Wnt signaling in bone metabolism and diseases. Semin Arthritis Rheum 2013; 43:220-40. [DOI: 10.1016/j.semarthrit.2013.01.004] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 01/11/2013] [Accepted: 01/16/2013] [Indexed: 12/17/2022]
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Van Camp JK, Beckers S, Zegers D, Boudin E, Nielsen TL, Andersen M, Roef G, Taes Y, Brixen K, Van Hul W. Genetic association study of WNT10B polymorphisms with BMD and adiposity parameters in Danish and Belgian males. Endocrine 2013; 44:247-54. [PMID: 23325361 DOI: 10.1007/s12020-012-9869-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 12/24/2012] [Indexed: 11/30/2022]
Abstract
Because of the importance of the Wnt pathway in the development and maintenance of both adipose and bone tissue, we wanted to evaluate the involvement of WNT10B, a Wnt pathway activator, in adipogenesis and osteoblastogenesis in humans. Genetic association between WNT10B polymorphisms and adiposity parameters as well as bone mineral density (BMD) measurements was analysed in two independent populations. The first is a population of 1,228 Danish men (702 aged 20-29 years; 532 aged 60-74 years) from the Odense Androgen Study (OAS), which was designed as a cross-sectional, population-based study. The second population, called SIBLOS, includes 922 Belgian men (34 ± 5 years old) and contains siblings selected from over 500 families. Four tagSNPs (rs833840, rs833841, rs10875902 and rs4018511) that capture variation of ten SNPs (MAF > 5 %) in a 15.2 kb region spanning the WNT10B gene and its flanking regions were genotyped. Although no association with body mass index was found, we found all tagSNPs to be associated with BMD parameters (BMD whole body, total hip and femoral neck) and height in the OAS population. The association of rs10875902 was most prominent (nominal p = 0.012) and confirmed a previously shown negative effect on BMD. No significant associations were observed in the SIBLOS population. In the present study, no association between WNT10B polymorphisms and adiposity parameters was found. However, our results clearly illustrate a role for WNT10B variants in determining human BMD. The effect of WNT10B polymorphisms on height should be evaluated in additional populations.
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Affiliation(s)
- Jasmijn K Van Camp
- Department of Medical Genetics, University of Antwerp, Prins Boudewijnlaan 43, 2650, Edegem, Antwerp, Belgium
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Boudin E, Jennes K, de Freitas F, Tegay D, Mortier G, Van Hul W. No mutations in the serotonin related TPH1 and HTR1B genes in patients with monogenic sclerosing bone disorders. Bone 2013; 55:52-6. [PMID: 23563356 DOI: 10.1016/j.bone.2013.03.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/25/2013] [Accepted: 03/21/2013] [Indexed: 10/27/2022]
Abstract
Since the identification of LRP5 as the causative gene for the osteoporosis pseudoglioma syndrome (OPPG) as well as the high bone mass (HBM) phenotype, LRP5 and the Wnt/β-catenin signaling have been extensively studied for their role in the differentiation and proliferation of osteoblasts, in the apoptosis of osteoblasts and osteocytes and in the response of bone to mechanical loading. However, more recently the direct effect of LRP5 on osteoblasts and bone formation has been questioned. Gene expression studies showed that mice lacking lrp5 have increased expression of tph1, the rate limiting enzyme for the production of serotonin in the gut. Furthermore mice lacking either tph1 or htr1B, the receptor for serotonin on the osteoblasts, were reported to have an increased bone mass due to increased bone formation. This led to the still controversial hypothesis that LRP5 influences bone formation indirectly by regulating the expression of thp1 and as a consequence influencing the production of serotonin in the gut. Based on these data we decided to evaluate the role of TPH1 and HTR1B in the development of craniotubular hyperostoses, a group of monogenic sclerosing bone dysplasias. We screened the coding regions of both genes in 53 patients lacking a mutation in the known causative genes LRP5, LRP4 and SOST. We could not find disease-causing coding variants in neither of the tested genes and therefore, we cannot provide support for an important function of TPH1 and HTR1B in the pathogenesis of sclerosing bone dysplasias in our tested patient cohort.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University and University Hospital of Antwerp, Edegem, Belgium.
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Boudin E, Steenackers E, de Freitas F, Nielsen TL, Andersen M, Brixen K, Van Hul W, Piters E. A common LRP4 haplotype is associated with bone mineral density and hip geometry in men-data from the Odense Androgen Study (OAS). Bone 2013; 53:414-20. [PMID: 23321396 DOI: 10.1016/j.bone.2013.01.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2012] [Revised: 01/02/2013] [Accepted: 01/08/2013] [Indexed: 11/15/2022]
Abstract
Osteoporosis is a common disease characterized by an increased susceptibility to fracture. It is a complex disorder resulting from the interaction of several polymorphisms in different genes and environmental factors. Since we recently reported a role for low density lipoprotein-related protein (LRP)-4 in monogenic disorders with bone overgrowth, we now wanted to evaluate whether genetic variation in the LRP4 gene has an effect on the susceptibility to osteoporosis in a population based cohort from the Odense Androgen Study. We chose to genotype four common (minor allele frequency (MAF)≥0.05) and non-synonymous coding polymorphisms located in the extracellular region of the LRP4 protein: rs3816614 (A/g), rs2306029 (G/a), rs2306033 (C/t) and rs6485702 (G/a) (large and small characters indicate major and minor alleles, respectively). Bone mineral density (BMD) measurements of the hip, the spine and whole body as well as different hip geometry parameters were available for a total of 1404 Danish men from two age groups ([20-29 years]: n=804; [60-74 years]: n=600). Using linear regression analysis adjusted for age, height and weight, we found significant associations between both rs2306029 and rs6485702 and BMD at all sites except the lumbar spine. The most significant association was found with whole body BMD (p=4.7×10(-5)). In addition, we found these two polymorphisms to be associated with different geometry parameters especially of the femoral shaft. Analysis of the two associated SNPs in the separate age groups demonstrated that most associations are only present in the youngest group of Danish men. In the group of elderly men, one Bonferroni corrected association between whole body BMD and rs6485702 was found to be significant. Subsequently, all polymorphisms were included in haplotype analyses using the PLINK software (v1.07). After adjusting for age, height and weight, two out of five common haplotypes (MAF≥0.01) were found to be of particular interest in the regulation of hip and whole body BMD (AGCG, AACA). Additional analysis suggested that these latter associations are driven by the association of rs6485702. We suggest, based on these results and the localisation of the variant in the third β-propeller domain of LRP4, that the variant has possibly a functional effect. Hereby, we conclude that common variation in the LRP4 gene determines hip and whole body BMD and thus confirm previous results from different GWAs. In addition, our data proves an additional role for LRP4 in regulating hip structure. Finally, interaction analysis for LRP4 with SOST and LRP5 showed interaction with LRP5 for femoral shaft geometry.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Belgium
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Bhadada SK, Rastogi A, Steenackers E, Boudin E, Arya A, Dhiman V, Bhansali A, Van Hul W. Novel SOST gene mutation in a sclerosteosis patient and her parents. Bone 2013; 52:707-10. [PMID: 23079137 DOI: 10.1016/j.bone.2012.10.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 10/08/2012] [Accepted: 10/08/2012] [Indexed: 10/27/2022]
Abstract
INTRODUCTION Sclerosteosis (OMIM 269500) is a rare autosomal recessive condition characterized by increased bone density associated with syndactyly. It is linked to a genetic defect in the SOST gene coding for sclerostin. So far, six different loss-of-function mutations in SOST have been reported in patients with sclerosteosis. Our objective was to sequence and identify mutation in the SOST and LRP5 genes which are known to be causal for craniotubular hyperostosis in a patient from India. PATIENT AND METHODS A 22year old woman presented with typical features of sclerosteosis in form of progressive visual and hearing loss, syndactyly and radiographs revealing increased density of bone. Genomic sequencing of the SOST gene as well as exons 2, 3 and 4 of the LRP5 gene was performed. RESULTS We identified a novel homozygous mutation in the (SOST) gene, characterized as one nucleotide insertion resulting in a frame shift mutation and loss of functional sclerostin. Her parents were also found to have a similar but heterozygous mutation in the (SOST) gene. CONCLUSION A novel frame shift mutation in the (SOST) gene causing loss of functional sclerostin was identified in a patient with sclerosteosis and her parents.
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Boudin E, Piters E, Fijalkowski I, Stevenheydens G, Steenackers E, Kuismin O, Moilanen JS, Mortier G, Van Hul W. Mutations in sFRP1 or sFRP4 are not a common cause of craniotubular hyperostosis. Bone 2013; 52:292-5. [PMID: 23044044 DOI: 10.1016/j.bone.2012.09.034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 09/26/2012] [Accepted: 09/27/2012] [Indexed: 01/10/2023]
Abstract
Sclerosing bone dysplasias are a heterogeneous group of rare diseases marked by increased BMD caused by either increased bone formation or by decreased bone resorption. In this study we have focused on craniotubular hyperostoses mainly affecting the long bones and the skull. Currently, there are three causative genes identified namely LRP5, SOST and LRP4. All three genes are involved in the canonical Wnt signalling pathway. These findings support the role of this pathway in regulating bone formation. The secreted Frizzled related proteins (sFRPs) can modulate the Wnt signalling pathway by binding to Wnt ligands or Frizzled receptors. Studies using mice showed that two members of this family, sFRP1 and sFRP4, have an important effect on bone formation. Sfrp1-/- mice have increased BMD values especially after peak BMD was reached. On the contrary, sfrp4 overexpression mice exhibit reduced BMD. Therefore, we selected sFRP1 and sFRP4, two members of the secreted Frizzled related protein (sFRP) family, as candidate genes for mutation analysis in patients with craniotubular hyperostosis. Using Sanger sequencing we screened the exons and intron/exon boundaries of sFRP1 and sFRP4 in 53 patients. In all patients mutations in LRP5, SOST and LRP4 were excluded. We identified two unknown heterozygous variants both in sFRP1. The first variant in sFRP1 is an intronic variant which, according to prediction programs, does not affect the splicing of the gene. The second variant (p.Trp131Arg/-) was identified in a young boy whose healthy mother does not carry the variant. In conclusion, our studies indicate that mutations neither in sFRP1 nor in sFRP4 are a common cause of craniotubular hyperostoses. As a consequence, further research will be necessary to identify the disease causing gene(s) in this group of patients.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University and University Hospital of Antwerp, Edegem, Belgium.
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Beckers S, Zegers D, Van Camp JK, Boudin E, Nielsen TL, Brixen K, Andersen M, Van Hul W. Resistin polymorphisms show associations with obesity, but not with bone parameters in men: results from the Odense Androgen Study. Mol Biol Rep 2012. [PMID: 23203410 DOI: 10.1007/s11033-012-2327-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Resistin is an obesity-related adipokine which has also been implicated in bone metabolism. Therefore, we designed a study to investigate the possible role of resistin gene variation in both obesity and bone mineral density. We included 1,155 individuals from the Odense Androgen Study (663 young subjects and 492 older subjects), a population-based, prospective, observational study on the inter-relationship between endocrine status, body composition, muscle function, and bone metabolism in men, in an association study with resistin (RETN) polymorphisms. Three RETN variants (rs1862513, rs3745367 and rs3745369) were genotyped with TaqMan Pre-Designed Genotyping assays. Linear regression was performed to investigate the possible association of these variants with several obesity- and bone-related parameters. After genotyping 1,155 Danish men, 663 young subjects and 492 older subjects, we found that rs3745367 was associated with several obesity-related measures in both the young and elderly cohort. Rs3745369 was only associated with obesity-phenotypes in the elderly cohort. When studying the combined cohorts, we could confirm the associations of rs3745367 with several obesity-related parameters. We were unable to identify any association between RETN polymorphisms and bone-related measurements. Together, these results illustrate resistin's role in the development of obesity. Rs3745367 gives the most consistent results in the current study and these should be confirmed in other populations. Research into its possible functional effect might also be required. A role for RETN variants in determining bone mineral density seems unlikely from our results.
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Affiliation(s)
- Sigri Beckers
- Centre for Medical Genetics, University of Antwerp, Universiteitsplein 1, 2610, Antwerp, Belgium.
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Boudin E, Piters E, Nielsen TL, Andersen M, Roef G, Taes Y, Brixen K, Van Hul W. Single nucleotide polymorphisms in sFRP4 are associated with bone and body composition related parameters in Danish but not in Belgian men. Mol Genet Metab 2012; 106:366-74. [PMID: 22608881 DOI: 10.1016/j.ymgme.2012.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 04/25/2012] [Accepted: 04/25/2012] [Indexed: 11/25/2022]
Abstract
The senescence accelerated mouse P6 (SAMP6) has a low bone mass and has previously shown to be a good model for senile osteoporosis in humans. In addition to a reduced bone mass, SAMP6 mice are obese and have hyperlipidemia. Using positional cloning and expression studies, an increased expression of sfrp4 was found in these mice. SFRP4 is a modulator of the Wnt signalling pathway. This pathway has been previously shown to be involved in regulating bone mass. Additional evidence that sFRP4 has an influence on BMD was delivered by linkage and association studies mostly performed in Asian populations. Based on these data we decided to perform an association study between common variants in sFRP4, BMD, hip geometry parameters and body composition parameters in a population consisting of 1383 Danish men (783 aged 20-29 years; 600 aged 60-74 years). Afterwards we tried to replicate the significant results in a population of 994 Belgian men. In the Danish population we found 6 SNPs associated with BMD at the hip and/or femoral neck. Furthermore, all 6 SNPs were associated with several hip geometry parameters. The homozygous presence of the minor allele resulted for all SNPs (except rs4720265) in a decrease in bone density and bone strength. Finally, we observed in the Danish population age specific associations with height and fat mass. In the Belgian population we tried to replicate the results of three SNPs with BMD and body composition parameters. Unfortunately, we were not able to replicate the results found in the Danish cohort but we found one SNP (rs2598116) associated with height. In conclusion, genetic variation in sFRP4 has an influence on hip fracture risk, percentage body fat and height in a Danish male population. However, we were unable to replicate these results in an independent Belgian population.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Belgium.
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Boudin E, Piters E, Fransen E, Nielsen TL, Andersen M, Roef G, Taes Y, Brixen K, Van Hul W. Association study of common variants in the sFRP1 gene region and parameters of bone strength and body composition in two independent healthy Caucasian male cohorts. Mol Genet Metab 2012; 105:508-15. [PMID: 22178351 DOI: 10.1016/j.ymgme.2011.11.189] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 11/15/2011] [Accepted: 11/15/2011] [Indexed: 12/24/2022]
Abstract
Bone mineral density (BMD) and bone strength are predictive parameters for the development of osteoporosis and related fracture later in life. Although it is well known that BMD and bone strength have a high heritability, not much of the variation is already explained. Mice models showed that sFRP1 has an influence on bone formation. Therefore this study aimed to investigate the effect of common genetic variation on BMD and bone strength in Caucasian men of different ages. Using HapMap we selected 13 tagSNPs which tag most common genetic variation in and around sFRP1 and we genotyped these SNPs in the young cohort of the Odense Androgen Study (OAS). The OAS includes a total of 1383 Danish men from two different age groups ([20-29 years]: N=783; [60-74 years]: N=600) and is well characterised. The subjects were phenotyped for BMD at several sites, and additionally for body composition and hip geometry parameters. Based on the results of the young cohort we selected three SNPs for further analysis in the complete OAS population. To conclude we tried to replicate the results of two SNPs in an independent population of 994 Belgian men. We found a strong association for rs9694405 with BMI as well in both cohorts separately as in the whole OAS population. Further we found rs4736965 associated with several hip geometry parameters in the same population. However we were not able to replicate those results in the Belgian population. At last we found in the OAS population age specific effects for rs10106678 with whole body BMD and waist to hip ratio.
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Affiliation(s)
- Eveline Boudin
- Department of Medical Genetics, University of Antwerp, Belgium.
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Pangrazio A, Boudin E, Piters E, Damante G, Iacono NL, D'Elia AV, Vezzoni P, Van Hul W, Villa A, Sobacchi C. Identification of the first deletion in the LRP5 gene in a patient with autosomal dominant osteopetrosis type I. Bone 2011; 49:568-71. [PMID: 21600326 PMCID: PMC3149657 DOI: 10.1016/j.bone.2011.05.006] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Revised: 05/04/2011] [Accepted: 05/04/2011] [Indexed: 10/28/2022]
Abstract
In the last decade, the low-density lipoprotein receptor-related protein 5 (LRP5) gene, coding for a coreceptor in the canonical Wnt signalling pathway, has been shown to play an important role in regulating bone mass and to be involved in the pathogenesis of several bone disorders. Here we describe a patient who presented with a clinical picture of Autosomal Dominant Osteopetrosis type I (ADO I), in whom we could identify the first deletion in the LRP5 gene causing increased bone mass. This mutation caused the in-frame deletion of two amino acids in the fourth blade of the first propeller of the protein, namely the highly conserved glycine at position 171 and the following glutamate residue. In vitro studies suggested that the pathogenic effect of this novel mutation could be due to a decreased inhibition of Wnt signalling by the antagonistic proteins sclerostin and Dickkopf-1, encoded respectively by the SOST and DKK1 genes, in the presence of mutated LRP5. Our results highlight an increasing molecular heterogeneity in LRP5-related bone diseases.
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Affiliation(s)
- Alessandra Pangrazio
- Institute of Genetic and Biomedical Research (IRGB) - Milan Section, National Research Council, 20138 Milan, Italy
- Istituto Clinico Humanitas IRCCS, 20089 Rozzano, Italy
| | - Eveline Boudin
- Department of Medical Genetics, University of Antwerp, 2610 Antwerp, Belgium
| | - Elke Piters
- Department of Medical Genetics, University of Antwerp, 2610 Antwerp, Belgium
| | - Giuseppe Damante
- Azienda Ospedaliero-Universitaria di Udine, Istituto di Genetica, 33100 Udine, Italy
| | - Nadia Lo Iacono
- Institute of Genetic and Biomedical Research (IRGB) - Milan Section, National Research Council, 20138 Milan, Italy
- Istituto Clinico Humanitas IRCCS, 20089 Rozzano, Italy
| | | | - Paolo Vezzoni
- Institute of Genetic and Biomedical Research (IRGB) - Milan Section, National Research Council, 20138 Milan, Italy
- Istituto Clinico Humanitas IRCCS, 20089 Rozzano, Italy
| | - Wim Van Hul
- Department of Medical Genetics, University of Antwerp, 2610 Antwerp, Belgium
| | - Anna Villa
- Institute of Genetic and Biomedical Research (IRGB) - Milan Section, National Research Council, 20138 Milan, Italy
- Istituto Clinico Humanitas IRCCS, 20089 Rozzano, Italy
| | - Cristina Sobacchi
- Institute of Genetic and Biomedical Research (IRGB) - Milan Section, National Research Council, 20138 Milan, Italy
- Istituto Clinico Humanitas IRCCS, 20089 Rozzano, Italy
- Corresponding author at: Istituto Clinico Humanitas IRCCS, via Manzoni 113, 20089 Rozzano (MI), Italy. Fax: + 39 0282245191.
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Leupin O, Piters E, Halleux C, Hu S, Kramer I, Morvan F, Bouwmeester T, Schirle M, Bueno-Lozano M, Fuentes FJR, Itin PH, Boudin E, de Freitas F, Jennes K, Brannetti B, Charara N, Ebersbach H, Geisse S, Lu CX, Bauer A, Van Hul W, Kneissel M. Bone overgrowth-associated mutations in the LRP4 gene impair sclerostin facilitator function. J Biol Chem 2011; 286:19489-500. [PMID: 21471202 DOI: 10.1074/jbc.m110.190330] [Citation(s) in RCA: 209] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Humans lacking sclerostin display progressive bone overgrowth due to increased bone formation. Although it is well established that sclerostin is an osteocyte-secreted bone formation inhibitor, the underlying molecular mechanisms are not fully elucidated. We identified in tandem affinity purification proteomics screens LRP4 (low density lipoprotein-related protein 4) as a sclerostin interaction partner. Biochemical assays with recombinant proteins confirmed that sclerostin LRP4 interaction is direct. Interestingly, in vitro overexpression and RNAi-mediated knockdown experiments revealed that LRP4 specifically facilitates the previously described inhibitory action of sclerostin on Wnt1/β-catenin signaling. We found the extracellular β-propeller structured domain of LRP4 to be required for this sclerostin facilitator activity. Immunohistochemistry demonstrated that LRP4 protein is present in human and rodent osteoblasts and osteocytes, both presumed target cells of sclerostin action. Silencing of LRP4 by lentivirus-mediated shRNA delivery blocked sclerostin inhibitory action on in vitro bone mineralization. Notably, we identified two mutations in LRP4 (R1170W and W1186S) in patients suffering from bone overgrowth. We found that these mutations impair LRP4 interaction with sclerostin and its concomitant sclerostin facilitator effect. Together these data indicate that the interaction of sclerostin with LRP4 is required to mediate the inhibitory function of sclerostin on bone formation, thus identifying a novel role for LRP4 in bone.
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Affiliation(s)
- Olivier Leupin
- Musculoskeletal Disease Area, Novartis Institutes for Biomedical Research, Novartis Pharma AG, Basel, Switzerland.
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Piters E, Balemans W, Nielsen TL, Andersen M, Boudin E, Brixen K, Van Hul W. Common genetic variation in the DKK1 gene is associated with hip axis length but not with bone mineral density and bone turnover markers in young adult men: results from the Odense Androgen Study. Calcif Tissue Int 2010; 86:271-81. [PMID: 20101398 DOI: 10.1007/s00223-010-9334-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Accepted: 01/02/2010] [Indexed: 12/17/2022]
Abstract
LRP5 was recently confirmed as an important susceptibility gene for osteoporosis. Our objective was to evaluate the effect of DKK1 polymorphisms on bone mineral density (BMD), hip geometry, and bone turnover. DKK1 is a secreted protein that binds to LRP5/6 receptors and inhibits canonical Wnt signaling. Using HapMap, we selected three SNPs covering the genetic variation in a 13.53-kb region comprising DKK1. The Odense Androgen Study is a population-based study comprising 783 Caucasian men aged 20-29 years. BMD and hip structural parameters were available for study. Bone turnover markers were used as a secondary end point. All analyses were repeated after adjusting for covariables and in subgroups according to physical activity. We found no significant association between DKK1 and BMD or markers of bone turnover; however, a significant association (P = 0.012) was found for rs1569198 with hip axis length (HAL), independent of BMD and height. Moreover, the association seemed to be driven by the non-sedentary subgroup (P = 0.004). Haplotype analysis further confirmed the association of rs1569198 with HAL. Furthermore, we obtained indications for interaction between DKK1 and LRP5 genotypes for different hip geometry parameters. As almost all variance within the DKK1 gene was covered, we conclude that common variation in this gene does not markedly influence BMD or bone turnover markers in young men. In this population, however, a common SNP in DKK1 does have a significant effect on HAL, implying a possible effect on hip fracture risk in the general population. This finding could be of interest but needs replication in independent populations.
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Affiliation(s)
- Elke Piters
- Department of Medical Genetics, University of Antwerp and University Hospital, Antwerp, Belgium.
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Piters E, Boudin E, Van Hul W. Wnt signaling: A win for bone. Arch Biochem Biophys 2008; 473:112-6. [DOI: 10.1016/j.abb.2008.03.006] [Citation(s) in RCA: 101] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2008] [Revised: 03/04/2008] [Accepted: 03/05/2008] [Indexed: 01/22/2023]
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