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Nikolaou S, Chatzikomninos I, Palavos I, Langourani-Kosteletou P, Vitoula K. Osteoporotic Burst Fracture in a Young Male Adult as First Presentation of a Rare PLS3 Mutation: A Case Report. Cureus 2023; 15:e51264. [PMID: 38283430 PMCID: PMC10822049 DOI: 10.7759/cureus.51264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/28/2023] [Indexed: 01/30/2024] Open
Abstract
Low-impact spinal fractures in young patients are rare and should raise suspicion of an underlying condition, as these injuries are typically the result of high-energy trauma. We describe a case of a young male patient who sustained a burst fracture of the first lumbar vertebra (L1) following low-energy trauma. The patient underwent percutaneous posterior spinal instrumentation, yet the poor bone quality detected intraoperatively prompted further diagnostic evaluation. Subsequently, low bone mineral density (BMD) was detected, and a rare plastine-3 (PLS3) gene mutation was revealed in the genetic analysis. The patient was initiated on teriparatide therapy after the discovery of osteoporosis postoperatively. It is, therefore, imperative to investigate all young patients with low-energy spinal fractures preoperatively to discover the underlying pathology promptly.
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Affiliation(s)
- Stefania Nikolaou
- 2nd Orthopaedic Department, KAT Attica General Hospital, Athens, GRC
| | | | - Ioannis Palavos
- Spine and Scoliosis Department, KAT Attica General Hospital, Athens, GRC
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2
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Verdonk SJE, Storoni S, Zhytnik L, Zhong W, Pals G, van Royen BJ, Elting MW, Maugeri A, Eekhoff EMW, Micha D. Medical Care Use Among Patients with Monogenic Osteoporosis Due to Rare Variants in LRP5, PLS3, or WNT1. Calcif Tissue Int 2023:10.1007/s00223-023-01101-3. [PMID: 37277619 PMCID: PMC10371905 DOI: 10.1007/s00223-023-01101-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/19/2023] [Indexed: 06/07/2023]
Abstract
Pathogenic variants in the LRP5, PLS3, or WNT1 genes can significantly affect bone mineral density, causing monogenic osteoporosis. Much remains to be discovered about the phenotype and medical care needs of these patients. The purpose of this study was to examine the use of medical care among Dutch individuals identified between 2014 and 2021 with a pathogenic or suspicious rare variant in LRP5, PLS3, or WNT1. In addition, the aim was to compare their medical care utilization to both the overall Dutch population and the Dutch Osteogenesis Imperfecta (OI) population. The Amsterdam UMC Genome Database was used to match 92 patients with the Statistics Netherlands (CBS) cohort. Patients were categorized based on their harbored variants: LRP5, PLS3, or WNT1. Hospital admissions, outpatient visits, medication data, and diagnosis treatment combinations (DTCs) were compared between the variant groups and, when possible, to the total population and OI population. Compared to the total population, patients with an LRP5, PLS3, or WNT1 variant had 1.63 times more hospital admissions, 2.0 times more opened DTCs, and a greater proportion using medication. Compared to OI patients, they had 0.62 times fewer admissions. Dutch patients with an LRP5, PLS3, or WNT1 variant appear to require on average more medical care than the total population. As expected, they made higher use of care at the surgical and orthopedic departments. Additionally, they used more care at the audiological centers and the otorhinolaryngology (ENT) department, suggesting a higher risk of hearing-related problems.
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Affiliation(s)
- S J E Verdonk
- Department of Internal Medicine Section Endocrinology, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands
| | - S Storoni
- Department of Internal Medicine Section Endocrinology, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands
| | - L Zhytnik
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
- Department of Traumatology and Orthopedics, University of Tartu, Tartu, Estonia
| | - W Zhong
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - G Pals
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - B J van Royen
- Department of Orthopedic Surgery and Sports Medicine, Amsterdam UMC Location University of Amsterdam and Location Vrije Universiteit Amsterdam, Meibergdreef 9, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Musculoskeletal Health, Amsterdam, The Netherlands
| | - M W Elting
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - A Maugeri
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
| | - E M W Eekhoff
- Department of Internal Medicine Section Endocrinology, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands.
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands.
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands.
| | - D Micha
- Rare Bone Disease Center Amsterdam, Amsterdam, The Netherlands
- Amsterdam Movement Sciences, Tissue Function and Regeneration, Amsterdam, The Netherlands
- Department of Human Genetics, Amsterdam UMC Location Vrije Universiteit Amsterdam, De Boelelaan 1117, Amsterdam, The Netherlands
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3
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Costantini A, Mäkitie RE, Hartmann MA, Fratzl-Zelman N, Zillikens MC, Kornak U, Søe K, Mäkitie O. Early-Onset Osteoporosis: Rare Monogenic Forms Elucidate the Complexity of Disease Pathogenesis Beyond Type I Collagen. J Bone Miner Res 2022; 37:1623-1641. [PMID: 35949115 PMCID: PMC9542053 DOI: 10.1002/jbmr.4668] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 07/22/2022] [Accepted: 08/01/2022] [Indexed: 12/05/2022]
Abstract
Early-onset osteoporosis (EOOP), characterized by low bone mineral density (BMD) and fractures, affects children, premenopausal women and men aged <50 years. EOOP may be secondary to a chronic illness, long-term medication, nutritional deficiencies, etc. If no such cause is identified, EOOP is regarded primary and may then be related to rare variants in genes playing a pivotal role in bone homeostasis. If the cause remains unknown, EOOP is considered idiopathic. The scope of this review is to guide through clinical and genetic diagnostics of EOOP, summarize the present knowledge on rare monogenic forms of EOOP, and describe how analysis of bone biopsy samples can lead to a better understanding of the disease pathogenesis. The diagnostic pathway of EOOP is often complicated and extensive assessments may be needed to reliably exclude secondary causes. Due to the genetic heterogeneity and overlapping features in the various genetic forms of EOOP and other bone fragility disorders, the genetic diagnosis usually requires the use of next-generation sequencing to investigate several genes simultaneously. Recent discoveries have elucidated the complexity of disease pathogenesis both regarding genetic architecture and bone tissue-level pathology. Two rare monogenic forms of EOOP are due to defects in genes partaking in the canonical WNT pathway: LRP5 and WNT1. Variants in the genes encoding plastin-3 (PLS3) and sphingomyelin synthase 2 (SGMS2) have also been found in children and young adults with skeletal fragility. The molecular mechanisms leading from gene defects to clinical manifestations are often not fully understood. Detailed analysis of patient-derived transiliac bone biopsies gives valuable information to understand disease pathogenesis, distinguishes EOOP from other bone fragility disorders, and guides in patient management, but is not widely available in clinical settings. Despite the great advances in this field, EOOP remains an insufficiently explored entity and further research is needed to optimize diagnostic and therapeutic approaches. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Alice Costantini
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Paris Cité University, INSERM UMR1163, Institut Imagine, Paris, France
| | - Riikka E Mäkitie
- Folkhälsan Institute of Genetics, Helsinki, Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Department of Otorhinolaryngology-Head and Neck Surgery, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department Hanusch Hospital, Vienna, Austria.,Vienna Bone and Growth Center, Vienna, Austria
| | - M Carola Zillikens
- Bone Center, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Uwe Kornak
- Institute of Human Genetics, University Medical Center Göttingen, Göttingen, Germany
| | - Kent Søe
- Clinical Cell Biology, Department of Pathology, Odense University Hospital, Odense, Denmark.,Clinical Cell Biology, Pathology Research Unit, Department of Clinical Research, University of Southern Denmark, Odense, Denmark.,Department of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Outi Mäkitie
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Folkhälsan Institute of Genetics, Helsinki, Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Children's Hospital and Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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4
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Drug Treatment of Low Bone Mass and Other Bone Conditions in Pediatric Patients. Paediatr Drugs 2022; 24:103-119. [PMID: 35013997 DOI: 10.1007/s40272-021-00487-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/01/2021] [Indexed: 10/19/2022]
Abstract
Osteoporosis may affect young individuals, albeit infrequently. In childhood, bone mass increases, reaching its peak between the second and third decades; then, after a period of stability, it gradually declines. Several conditions, including genetic disorders, chronic diseases, and some medications, can have an impact on bone homeostasis. Diagnosis in young patients is based on the criteria defined by the International Society for Clinical Densitometry (ISCD), published in 2013. High risk factors should be identified and monitored. Often simple interventions aimed to eliminate the underlying cause, to minimize the negative bone effects linked to drugs, or to increase calcium and vitamin D intake can protect bone mass. However, in selected cases, pharmacological treatment should be considered. Bisphosphonates remain the main therapeutic agent for children with significant skeletal fragility and are also useful in a large number of other bone conditions. Denosumab, an anti-RANKL antibody, could become a potential alternative treatment. Clinical trials to evaluate the long-term effects and safety of denosumab in children are ongoing.
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5
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Rouleau C, Malorie M, Collet C, Porquet-Bordes V, Gennero I, Eddiry S, Laroche M, Salles JP, Couture G, Edouard T. Diagnostic yield of bone fragility gene panel sequencing in children and young adults referred for idiopathic primary osteoporosis at a single regional reference centre. Bone Rep 2022; 16:101176. [PMID: 35252483 PMCID: PMC8892094 DOI: 10.1016/j.bonr.2022.101176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 11/22/2022] Open
Abstract
Aim To describe the presenting features, bone characteristics and molecular genetics in a large monocentric cohort of children and young adults with idiopathic primary osteoporosis. Methods Sixty-six patients (19 children, 47 adults; 28 males, 38 females; age at referral: 3.8 to 65 years) diagnosed with primary osteoporosis were included in this study; patients with features of osteogenesis imperfecta or other known syndromes associated with osteoporosis were excluded. For each patient, the following data were collected by retrospective chart review: family and personal history of fracture and osteoporosis, mineral homeostasis parameters and markers of bone formation and resorption, bone mineral density (BMD) of the lumbar spine (LS-BMD), the total body less head (TB-BMD), and total hip levels (TH-BMD) measured by DXA. As part of the initial assessment process, a bone fragility gene panel sequencing was performed in all of these patients. Results There was a higher predominance of males in the children (63%) and of females in the adults (66%) (p = 0.030). Compared to the adults, the children had a significantly lower frequency of vertebral fractures (26 vs 57%, p = 0.022) and a higher frequency of peripheral fractures (84 vs 53%; p = 0.019). Bone fragility gene panel sequencing allowed the identification of the heterozygous pathogenic variant in 27% of patients (most frequently in LRP5, WNT1 and COL1A1 or 2 genes) and the heterozygous p.(Val667Met) LRP5 variant in 11% of them. The frequency of pathogenic variants tended to be higher in the children compared to the adults without reaching statistical significance (42 vs 19%; p = 0.053). The frequency of the p.(Val667Met) LRP5 variant was similar in children and adults. No significant differences were found regarding the various clinical, biological and radiological characteristics of the patients according to genotype. Conclusion In this study, we reported the presenting features and bone characteristics in a large cohort of children and young adults with idiopathic primary osteoporosis. Bone fragility gene panel sequencing allowed the identification of genetic variants in a significant proportion of these patients. Molecular diagnosis in these patients is important in order to be able to offer genetic counselling and organise patient management.
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Ciancia S, van Rijn RR, Högler W, Appelman-Dijkstra NM, Boot AM, Sas TCJ, Renes JS. Osteoporosis in children and adolescents: when to suspect and how to diagnose it. Eur J Pediatr 2022; 181:2549-2561. [PMID: 35384509 PMCID: PMC9192469 DOI: 10.1007/s00431-022-04455-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 02/07/2023]
Abstract
UNLABELLED Early recognition of osteoporosis in children and adolescents is important in order to establish an appropriate diagnosis of the underlying condition and to initiate treatment if necessary. In this review, we present the diagnostic work-up, and its pitfalls, of pediatric patients suspected of osteoporosis including a careful collection of the medical and personal history, a complete physical examination, biochemical data, molecular genetics, and imaging techniques. The most recent and relevant literature has been reviewed to offer a broad overview on the topic. Genetic and acquired pediatric bone disorders are relatively common and cause substantial morbidity. In recent years, there has been significant progress in the understanding of the genetic and molecular mechanistic basis of bone fragility and in the identification of acquired causes of osteoporosis in children. Specifically, drugs that can negatively impact bone health (e.g. steroids) and immobilization related to acute and chronic diseases (e.g. Duchenne muscular dystrophy) represent major risk factors for the development of secondary osteoporosis and therefore an indication to screen for bone mineral density and vertebral fractures. Long-term studies in children chronically treated with steroids have resulted in the development of systematic approaches to diagnose and manage pediatric osteoporosis. CONCLUSIONS Osteoporosis in children requires consultation with and/or referral to a pediatric bone specialist. This is particularly relevant since children possess the unique ability for spontaneous and medication-assisted recovery, including reshaping of vertebral fractures. As such, pediatricians have an opportunity to improve bone mass accrual and musculoskeletal health in osteoporotic children. WHAT IS KNOWN • Both genetic and acquired pediatric disorders can compromise bone health and predispose to fractures early in life. • The identification of children at risk of osteoporosis is essential to make a timely diagnosis and start the treatment, if necessary. WHAT IS NEW • Pediatricians have an opportunity to improve bone mass accrual and musculoskeletal health in osteoporotic children and children at risk of osteoporosis. • We offer an extensive but concise overview about the risk factors for osteoporosis and the diagnostic work-up (and its pitfalls) of pediatric patients suspected of osteoporosis.
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Affiliation(s)
- Silvia Ciancia
- Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center, Sophia Children's Hospital, Rotterdam, The Netherlands.
| | - Rick R. van Rijn
- grid.7177.60000000084992262Department of Radiology and Nuclear Medicine, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Wolfgang Högler
- grid.9970.70000 0001 1941 5140Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Natasha M. Appelman-Dijkstra
- grid.10419.3d0000000089452978Department of Internal Medicine, Subdivision of Endocrinology, Center for Bone Quality, Leiden University Medical Center, Leiden, The Netherlands
| | - Annemieke M. Boot
- grid.4830.f0000 0004 0407 1981Department of Pediatrics, Subdivision of Endocrinology, University Medical Center Groningen, Beatrix Children’s Hospital, University of Groningen, Groningen, The Netherlands
| | - Theo C. J. Sas
- grid.416135.40000 0004 0649 0805Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center, Sophia Children’s Hospital, Rotterdam, The Netherlands ,Diabeter, Center for Pediatric and Adult Diabetes Care and Research, Rotterdam, The Netherlands
| | - Judith S. Renes
- grid.416135.40000 0004 0649 0805Department of Pediatrics, Subdivision of Endocrinology, Erasmus University Medical Center, Sophia Children’s Hospital, Rotterdam, The Netherlands
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7
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Campopiano MC, Fogli A, Michelucci A, Mazoni L, Longo A, Borsari S, Pardi E, Benelli E, Sardella C, Pierotti L, Dinoi E, Marcocci C, Cetani F. Case report: Early-onset osteoporosis in a patient carrying a novel heterozygous variant of the WNT1 gene. Front Endocrinol (Lausanne) 2022; 13:918682. [PMID: 36004351 PMCID: PMC9393300 DOI: 10.3389/fendo.2022.918682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 07/14/2022] [Indexed: 12/02/2022] Open
Abstract
The WNT1 gene is crucial for bone development and homeostasis. Homozygous mutations in WNT1 cause severe bone fragility known as osteogenesis imperfecta type XV. Moreover, heterozygous WNT1 mutations have been found in adults with early-onset osteoporosis. We identified a 35 year-old Caucasian woman who experienced multiple vertebral fractures two months after her second pregnancy. There was no history of risk factors for secondary osteoporosis or family history of osteoporosis. Dual-energy X-ray absorptiometry confirmed a marked reduction of bone mineral density (BMD) at the lumbar spine (0.734 g/cm2, Z-score -2.8), femoral neck (0.48 g/cm2, Z-score -3.5), and total hip (0.589 g/cm2, Z-score -3.0). Blood tests excluded secondary causes of bone fragility. Genetic analysis revealed a heterozygous missense mutation (p.Leu370Val) in the WNT1 gene. Varsome classified it as a variant of uncertain significance. However, the fact that the Leucine residue at position 370 is highly conserved among vertebrate species and the variant has a very low allelic frequency in the general population would exclude the possibility of a polymorphism. The patient was treated for two years with teriparatide therapy associated with calcium and vitamin D supplements. During the follow-up period she did not report further clinical fractures. After 24 months of teriparatide, BMD increased at lumbar spine (+14.6%), femoral neck (+8.3%) and total hip (+4.9%) compared to baseline. We confirm that the heterozygous WNT1 mutation could cause a variable bone fragility and low turnover osteoporosis. We suggest that teriparatide is one of the most appropriate available therapies for this case.
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Affiliation(s)
- Maria Cristina Campopiano
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Antonella Fogli
- Laboratory of Molecular Genetics, University Hospital of Pisa, Pisa, Italy
| | - Angela Michelucci
- Laboratory of Molecular Genetics, University Hospital of Pisa, Pisa, Italy
| | - Laura Mazoni
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Antonella Longo
- Department of Biological Sciences and BioDiscovery Institute, University of North Texas, Denton, TX, United States
| | - Simona Borsari
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Elena Pardi
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Elena Benelli
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Chiara Sardella
- Unit of Endocrinology, University Hospital of Pisa, Pisa, Italy
| | - Laura Pierotti
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Elisa Dinoi
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
| | - Claudio Marcocci
- Department of Clinical and Experimental Medicine, Unit of Endocrinology, University of Pisa, Pisa, Italy
- Unit of Endocrinology, University Hospital of Pisa, Pisa, Italy
| | - Filomena Cetani
- Unit of Endocrinology, University Hospital of Pisa, Pisa, Italy
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8
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Ghatan S, Costantini A, Li R, De Bruin C, Appelman-Dijkstra NM, Winter EM, Oei L, Medina-Gomez C. The Polygenic and Monogenic Basis of Paediatric Fractures. Curr Osteoporos Rep 2021; 19:481-493. [PMID: 33945105 PMCID: PMC8551106 DOI: 10.1007/s11914-021-00680-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/15/2021] [Indexed: 01/19/2023]
Abstract
PURPOSE OF REVIEW Fractures are frequently encountered in paediatric practice. Although recurrent fractures in children usually unveil a monogenic syndrome, paediatric fracture risk could be shaped by the individual genetic background influencing the acquisition of bone mineral density, and therefore, the skeletal fragility as shown in adults. Here, we examine paediatric fractures from the perspective of monogenic and complex trait genetics. RECENT FINDINGS Large-scale genome-wide studies in children have identified ~44 genetic loci associated with fracture or bone traits whereas ~35 monogenic diseases characterized by paediatric fractures have been described. Genetic variation can predispose to paediatric fractures through monogenic risk variants with a large effect and polygenic risk involving many variants of small effects. Studying genetic factors influencing peak bone attainment might help in identifying individuals at higher risk of developing early-onset osteoporosis and discovering drug targets to be used as bone restorative pharmacotherapies to prevent, or even reverse, bone loss later in life.
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Affiliation(s)
- S Ghatan
- Translational Skeletal Genomics Group, Department of Internal Medicine, Erasmus MC University Medical Centre, Doctor Molewaterplein 40, Ee-571, 3015, GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands
| | - A Costantini
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - R Li
- Translational Skeletal Genomics Group, Department of Internal Medicine, Erasmus MC University Medical Centre, Doctor Molewaterplein 40, Ee-571, 3015, GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands
| | - C De Bruin
- Department of Paediatrics, Leiden University Medical Centre, Leiden, The Netherlands
| | - N M Appelman-Dijkstra
- Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - E M Winter
- Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - L Oei
- Translational Skeletal Genomics Group, Department of Internal Medicine, Erasmus MC University Medical Centre, Doctor Molewaterplein 40, Ee-571, 3015, GD, Rotterdam, The Netherlands
- Department of Epidemiology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands
- Department of Internal Medicine, Leiden University Medical Centre, Leiden, The Netherlands
| | - Carolina Medina-Gomez
- Translational Skeletal Genomics Group, Department of Internal Medicine, Erasmus MC University Medical Centre, Doctor Molewaterplein 40, Ee-571, 3015, GD, Rotterdam, The Netherlands.
- Department of Epidemiology, Erasmus MC University Medical Centre, Rotterdam, The Netherlands.
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9
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Plastin 3 in health and disease: a matter of balance. Cell Mol Life Sci 2021; 78:5275-5301. [PMID: 34023917 PMCID: PMC8257523 DOI: 10.1007/s00018-021-03843-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/06/2021] [Accepted: 04/20/2021] [Indexed: 02/06/2023]
Abstract
For a long time, PLS3 (plastin 3, also known as T-plastin or fimbrin) has been considered a rather inconspicuous protein, involved in F-actin-binding and -bundling. However, in recent years, a plethora of discoveries have turned PLS3 into a highly interesting protein involved in many cellular processes, signaling pathways, and diseases. PLS3 is localized on the X-chromosome, but shows sex-specific, inter-individual and tissue-specific expression variability pointing towards skewed X-inactivation. PLS3 is expressed in all solid tissues but usually not in hematopoietic cells. When escaping X-inactivation, PLS3 triggers a plethora of different types of cancers. Elevated PLS3 levels are considered a prognostic biomarker for cancer and refractory response to therapies. When it is knocked out or mutated in humans and mice, it causes osteoporosis with bone fractures; it is the only protein involved in actin dynamics responsible for osteoporosis. Instead, when PLS3 is upregulated, it acts as a highly protective SMN-independent modifier in spinal muscular atrophy (SMA). Here, it seems to counteract reduced F-actin levels by restoring impaired endocytosis and disturbed calcium homeostasis caused by reduced SMN levels. In contrast, an upregulation of PLS3 on wild-type level might cause osteoarthritis. This emphasizes that the amount of PLS3 in our cells must be precisely balanced; both too much and too little can be detrimental. Actin-dynamics, regulated by PLS3 among others, are crucial in a lot of cellular processes including endocytosis, cell migration, axonal growth, neurotransmission, translation, and others. Also, PLS3 levels influence the infection with different bacteria, mycosis, and other pathogens.
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10
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Fratzl-Zelman N, Wesseling-Perry K, Mäkitie RE, Blouin S, Hartmann MA, Zwerina J, Välimäki VV, Laine CM, Välimäki MJ, Pereira RC, Mäkitie O. Bone material properties and response to teriparatide in osteoporosis due to WNT1 and PLS3 mutations. Bone 2021; 146:115900. [PMID: 33618074 DOI: 10.1016/j.bone.2021.115900] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/11/2021] [Accepted: 02/15/2021] [Indexed: 12/22/2022]
Abstract
CONTEXT Patients with osteoporosis-associated WNT1 or PLS3 mutations have unique bone histomorphometric features and osteocyte-specific hormone expression patterns. OBJECTIVE To investigate the effects of WNT1 and PLS3 mutations on bone material properties. DESIGN Transiliac bone biopsies were evaluated by quantitative backscattered electron imaging, immunohistochemistry, and bone histomorphometry. SETTING Ambulatory patients. PATIENTS Three pediatric and eight adult patients with WNT1 or PLS3 mutations. INTERVENTION Bone mineralization density distribution and osteocyte protein expression was evaluated in 11 patients and repeated in six patients who underwent repeat biopsy after 24 months of teriparatide treatment. MAIN OUTCOME MEASURE Bone mineralization density distribution and protein expression. RESULTS Children with WNT1 or PLS3 mutations had heterogeneous bone matrix mineralization, consistent with bone modeling during growth. Bone matrix mineralization was homogenous in adults and increased throughout the age spectrum. Teriparatide had very little effect on matrix mineralization or bone formation in patients with WNT1 or PLS3 mutations. However, teriparatide decreased trabecular osteocyte lacunae size and increased trabecular bone FGF23 expression. CONCLUSION The contrast between preserved bone formation with heterogeneous mineralization in children and low bone turnover with homogenous bone mineral content in adults suggests that WNT1 and PLS3 have differential effects on bone modeling and remodeling. The lack of change in matrix mineralization in response to teriparatide, despite clear changes in osteocyte lacunae size and protein expression, suggests that altered WNT1 and PLS3 expression may interfere with coupling of osteocyte, osteoblast, and osteoclast function. Further studies are warranted to determine the mechanism of these changes.
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Affiliation(s)
- Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | | | - Riikka E Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
| | - Stéphane Blouin
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Markus A Hartmann
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Jochen Zwerina
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of OEGK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Ville-Valtteri Välimäki
- Department of Orthopaedics and Traumatology, Helsinki University Central Hospital and Helsinki University, Jorvi Hospital, Espoo, Finland
| | - Christine M Laine
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital and University of Gothenburg, Gothenburg, Sweden
| | - Matti J Välimäki
- Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland
| | - Renata C Pereira
- Department of Pediatrics, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland; Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska University Hospital and University of Gothenburg, Gothenburg, Sweden; Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Molecular Medicine and Surgery, Karolinska Institutet and Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
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11
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Pathak JL, Bravenboer N, Klein-Nulend J. The Osteocyte as the New Discovery of Therapeutic Options in Rare Bone Diseases. Front Endocrinol (Lausanne) 2020; 11:405. [PMID: 32733380 PMCID: PMC7360678 DOI: 10.3389/fendo.2020.00405] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/20/2020] [Indexed: 01/18/2023] Open
Abstract
Osteocytes are the most abundant (~95%) cells in bone with the longest half-life (~25 years) in humans. In the past osteocytes have been regarded as vestigial cells in bone, since they are buried inside the tough bone matrix. However, during the last 30 years it has become clear that osteocytes are as important as bone forming osteoblasts and bone resorbing osteoclasts in maintaining bone homeostasis. The osteocyte cell body and dendritic processes reside in bone in a complex lacuno-canalicular system, which allows the direct networking of osteocytes to their neighboring osteocytes, osteoblasts, osteoclasts, bone marrow, blood vessels, and nerves. Mechanosensing of osteocytes translates the applied mechanical force on bone to cellular signaling and regulation of bone adaptation. The osteocyte lacuno-canalicular system is highly efficient in transferring external mechanical force on bone to the osteocyte cell body and dendritic processes via displacement of fluid in the lacuno-canalicular space. Osteocyte mechanotransduction regulates the formation and function of the osteoblasts and osteoclasts to maintain bone homeostasis. Osteocytes produce a variety of proteins and signaling molecules such as sclerostin, cathepsin K, Wnts, DKK1, DMP1, IGF1, and RANKL/OPG to regulate osteoblast and osteoclast activity. Various genetic abnormality-associated rare bone diseases are related to disrupted osteocyte functions, including sclerosteosis, van Buchem disease, hypophosphatemic rickets, and WNT1 and plastin3 mutation-related disorders. Meticulous studies during the last 15 years on disrupted osteocyte function in rare bone diseases guided for the development of various novel therapeutic agents to treat bone diseases. Studies on genetic, molecular, and cellular mechanisms of sclerosteosis and van Buchem disease revealed a role for sclerostin in bone homeostasis, which led to the development of the sclerostin antibody to treat osteoporosis and other bone degenerative diseases. The mechanism of many other rare bone diseases and the role of the osteocyte in the development of such conditions still needs to be investigated. In this review, we mainly discuss the knowledge obtained during the last 30 years on the role of the osteocyte in rare bone diseases. We speculate about future research directions to develop novel therapeutic drugs targeting osteocyte functions to treat both common and rare bone diseases.
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Affiliation(s)
- Janak L. Pathak
- Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, China
| | - Nathalie Bravenboer
- Department of Clinical Chemistry, Amsterdam University Medical Centers, Amsterdam Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - Jenneke Klein-Nulend
- Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou, China
- Department of Oral Cell Biology, Academic Centre for Dentistry Amsterdam, Amsterdam Movement Sciences, University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, Netherlands
- *Correspondence: Jenneke Klein-Nulend
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12
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Yu M, Wang H, Fan Z, Xie C, Liu H, Liu Y, Han D, Wong SW, Feng H. BMP4 mutations in tooth agenesis and low bone mass. Arch Oral Biol 2019; 103:40-46. [PMID: 31128441 DOI: 10.1016/j.archoralbio.2019.05.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 05/06/2019] [Accepted: 05/13/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE To identify an uncommon genetic cause of tooth agenesis (TA) by utilizing whole exome sequencing (WES) and targeted Sanger sequencing in a cohort of 120 patients with isolated TA. DESIGN One deleterious mutation in the gene encoding bone morphogenetic protein 4 (BMP4) was identified in 6 unrelated patients with TA by WES. After that, the coding exons of BMP4 were examined in 114 TA patients using Sanger sequencing. Dual-energy X-ray absorptiometry (DEXA) was used to measure the bone mineral density of patients who carried a BMP4 mutation. Finally, preliminary functional studies of two BMP4 mutants were performed. RESULTS We detected 3 novel missense mutations (c.58 G > A: p.Gly20Ser, c.326 G > T: p.Arg109Leu and c.614 T > C: p.Val205Ala) and 1 reported mutation in the BMP4 gene among 120 TA probands. The previously reported BMP4 mutation (c.751C > T: p.His251Tyr) was associated with urethra and eye anomalies. By extending the pedigrees, we determined that the tooth phenotypes had an autosomal dominant inheritance pattern, as individuals carrying a BMP4 mutation exhibit different types of dental anomalies. Interestingly, we observed that patients harboring a BMP4 mutation manifested early onset osteopenia or osteoporosis. Further in vitro functional assays demonstrated that two BMP4 mutants resulted in a decreased activation of Smad signaling. Therefore, a loss-of-function in BMP4 may contribute to the clinical phenotypes seen in this study. CONCLUSIONS We identified 4 mutations in the BMP4 gene in 120 TA patients. To our knowledge, this is the first study to describe human skeletal diseases associated with BMP4 mutations.
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Affiliation(s)
- Miao Yu
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China
| | - Hao Wang
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China
| | - Zhuangzhuang Fan
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China
| | - Chencheng Xie
- Department of Internal Medicine, Sanford Medical School, University of South Dakota, Sioux Falls, SD, 57105, USA
| | - Haochen Liu
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China
| | - Yang Liu
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China.
| | - Dong Han
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China.
| | - Sing-Wai Wong
- Department of Periodontology, Adams School of Dentistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA.
| | - Hailan Feng
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, China
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13
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Mäkitie RE, Costantini A, Kämpe A, Alm JJ, Mäkitie O. New Insights Into Monogenic Causes of Osteoporosis. Front Endocrinol (Lausanne) 2019; 10:70. [PMID: 30858824 PMCID: PMC6397842 DOI: 10.3389/fendo.2019.00070] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 01/24/2019] [Indexed: 12/17/2022] Open
Abstract
Osteoporosis, characterized by deteriorated bone microarchitecture and low bone mineral density, is a chronic skeletal disease with high worldwide prevalence. Osteoporosis related to aging is the most common form and causes significant morbidity and mortality. Rare, monogenic forms of osteoporosis have their onset usually in childhood or young adulthood and have specific phenotypic features and clinical course depending on the underlying cause. The most common form is osteogenesis imperfecta linked to mutations in COL1A1 and COL1A2, the two genes encoding type I collagen. However, in the past years, remarkable advancements in bone research have expanded our understanding of the intricacies behind bone metabolism and identified novel molecular mechanisms contributing to skeletal health and disease. Especially high-throughput sequencing techniques have made family-based studies an efficient way to identify single genes causative of rare monogenic forms of osteoporosis and these have yielded several novel genes that encode proteins partaking in type I collagen modification or regulating bone cell function directly. New forms of monogenic osteoporosis, such as autosomal dominant osteoporosis caused by WNT1 mutations or X-linked osteoporosis due to PLS3 mutations, have revealed previously unidentified bone-regulating proteins and clarified specific roles of bone cells, expanded our understanding of possible inheritance mechanisms and paces of disease progression, and highlighted the potential of monogenic bone diseases to extend beyond the skeletal tissue. The novel gene discoveries have introduced new challenges to the classification and diagnosis of monogenic osteoporosis, but also provided promising new molecular targets for development of pharmacotherapies. In this article we give an overview of the recent discoveries in the area of monogenic forms of osteoporosis, describing the key cellular mechanisms leading to skeletal fragility, the major recent research findings and the essential challenges and avenues in future diagnostics and treatments.
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Affiliation(s)
- Riikka E. Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Alice Costantini
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Anders Kämpe
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Jessica J. Alm
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
- Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Children's Hospital, Pediatric Research Center, University of Helsinki and HUS Helsinki University Hospital, Helsinki, Finland
- Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
- *Correspondence: Outi Mäkitie
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14
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Alhamdi S, Lee YC, Chowdhury S, Byers PH, Gottschalk M, Taft RJ, Joeng KS, Lee BH, Bird LM. Heterozygous WNT1 variant causing a variable bone phenotype. Am J Med Genet A 2018; 176:2419-2424. [PMID: 30246918 DOI: 10.1002/ajmg.a.40347] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 04/23/2018] [Accepted: 05/14/2018] [Indexed: 01/07/2023]
Abstract
Osteogenesis imperfecta (OI) is a family of heritable disorders of bone fragility. Most individuals with OI have mutations in the genes encoding type I collagen; at least 17 other genes have been associated with OI. Biallelic loss-of-function mutations in WNT1 cause severe OI. Heterozygous missense variants in WNT1 are responsible for early-onset osteoporosis with variable bone phenotypes. Herein, we report a third-generation family with four affected individuals, some presenting with multiple low-impact fractures in childhood and others presenting with early-onset osteoporosis without a striking fracture history. A WNT1 variant (c. 1051 > C; p.Trp351Arg) was identified in the proband and segregated with a bone phenotype in three additional family members, consistent with autosomal dominant inheritance. In the proband, whole genome sequencing also revealed a de novo duplication (434 kb) of 22q11.2 that involves 25 genes, 4 of which are associated with human disease when haploinsufficient. Though smaller than the typical (1.5 Mb) 22q11.2 duplication, the duplication in the proband may be responsible for additional nonosseous aspects of his phenotype (hypotonia, developmental delay, small genitalia, strabismus, and depression in preadolescence). This case demonstrates the variability of bone phenotype conferred by a WNT1 variant and extends the spectrum of bone phenotypes associated with heterozygous WNT1 mutations.
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Affiliation(s)
- Shatha Alhamdi
- University of California, San Diego, La Jolla, California
| | | | - Shimul Chowdhury
- Rady Children's Institute for Genomic Medicine, San Diego, California
| | | | - Michael Gottschalk
- University of California, San Diego, La Jolla, California.,Divisions of Endocrinology, Rady Children's Hospital San Diego, San Diego, California
| | - Ryan J Taft
- Illumina Clinical Services Laboratory, Illumina Inc., San Diego, California
| | | | | | - Lynne M Bird
- University of California, San Diego, La Jolla, California.,Divisions of Dysmorphology/Genetics, Rady Children's Hospital San Diego, San Diego, California
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15
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Costantini A, Krallis PΝ, Kämpe A, Karavitakis EM, Taylan F, Mäkitie O, Doulgeraki A. A novel frameshift deletion in PLS3 causing severe primary osteoporosis. J Hum Genet 2018; 63:923-926. [PMID: 29884797 DOI: 10.1038/s10038-018-0472-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Revised: 04/19/2018] [Accepted: 05/08/2018] [Indexed: 12/11/2022]
Abstract
Mutations in the gene encoding plastin-3, PLS3, have recently been associated to severe primary osteoporosis. The molecular function of plastin-3 is not fully understood. Since PLS3 is located on the X chromosome, males are usually more severely affected than females. PLS3 mutations have thus far been reported in approximately 20 young patients with low bone mineral density (BMD). We describe an 8-year-old Greek boy with severe primary osteoporosis with multiple vertebral compression fractures and one low-energy long bone fracture. His clinical manifestations were consistent with osteogenesis imperfecta, including blue sclerae, joint hypermobility, low bone mineral density, kyphosis, bilateral conductive hearing loss, and mild dysmorphic features. The family history was negative for primary osteoporosis. COL1A1 and COL1A2 mutations were excluded by Sanger sequencing. However, Sanger sequencing of PLS3 led to the identification of a de novo frameshift deletion, NM_005032: c.1096_1100delAACTT, p.(Asn366Serfs*5), in exon 10 confirming the diagnosis of PLS3 osteoporosis. In conclusion, we describe a novel frameshift deletion in PLS3 causing severe primary osteoporosis in a boy. Our finding highlights the clinical overlap between type I collagen and PLS3-related skeletal fragility and underscores the importance of PLS3 screening in patients with multiple fractures to enable proper genetic counseling.
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Affiliation(s)
- Alice Costantini
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
| | | | - Anders Kämpe
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | | | - Fulya Taylan
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Outi Mäkitie
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland.,Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Artemis Doulgeraki
- Department of Bone and Mineral Metabolism, Institute of Child Health, "Aghia Sophia" Children's Hospital, Athens, Greece
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16
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Balasubramanian M, Fratzl-Zelman N, O'Sullivan R, Bull M, Fa Peel N, Pollitt RC, Jones R, Milne E, Smith K, Roschger P, Klaushofer K, Bishop NJ. Novel PLS3 variants in X-linked osteoporosis: Exploring bone material properties. Am J Med Genet A 2018; 176:1578-1586. [PMID: 29736964 DOI: 10.1002/ajmg.a.38830] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 02/26/2018] [Accepted: 04/06/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND Idiopathic Juvenile Osteoporosis (IJO) refers to significantly lower than expected bone mass manifesting in childhood with no identifiable aetiology. IJO classically presents in early pubertal period with multiple fractures including metaphyseal and vertebral crush fractures, and low bone-mass. METHODS Here we describe two patients and provide information on their clinical phenotype, genotype and bone material analysis in one of the patients. RESULTS Patient 1: 40-year old adult male diagnosed with IJO in childhood who re-presented with a hip fracture as an adult. Genetic analysis identified a pathogenic PLS3 hemizygous variant, c.1765del in exon 16. Patient 2: 15-year old boy with multiple vertebral fractures and bone biopsy findings suggestive of IJO who also has a diagnosis of autism spectrum disorder. Genetic analysis identified a maternally inherited PLS3 pathogenic c.1295T>A variant in exon 12. Analyses of the transiliac bone sample revealed severe reduction of trabecular volume and bone turnover indices and elevated bone matrix mineralisation. DISCUSSION We propose that genetic testing for PLS3 should be undertaken in patients presenting with a current or previous history of IJO as this has implications for genetic counselling and cascade screening. The extensive evaluation of the transiliac biopsy sample of Patient 2 revealed a novel bone phenotype. CONCLUSION This report includes a review of IJO and genetic causes of osteoporosis, and suggests that existing cases of IJO should be screened for PLS3. Through analysis of bone material properties in Patient 2, we can conclude that PLS3 does have a role in bone mineralisation.
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Affiliation(s)
- Meena Balasubramanian
- Highly Specialised Severe, Complex & Atypical OI Service, Sheffield Children's NHS Foundation Trust, UK.,Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, UK
| | - Nadja Fratzl-Zelman
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of WGKK and AUVA Trauma Centre, Meidling, 1st Med. Dept. Hanusch Hospital, 1140 Vienna, Austria
| | | | - Mary Bull
- Metabolic Bone Centre, Northern General Hospital, Sheffield, UK
| | - Nicola Fa Peel
- Metabolic Bone Centre, Northern General Hospital, Sheffield, UK
| | - Rebecca C Pollitt
- Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, UK
| | - Rebecca Jones
- Department of Psychology, Sheffield Children's NHS Foundation Trust, UK
| | | | - Kath Smith
- Sheffield Diagnostic Genetics Service, Sheffield Children's NHS Foundation Trust, UK
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of WGKK and AUVA Trauma Centre, Meidling, 1st Med. Dept. Hanusch Hospital, 1140 Vienna, Austria
| | - Klaus Klaushofer
- Ludwig Boltzmann Institute of Osteology at Hanusch Hospital of WGKK and AUVA Trauma Centre, Meidling, 1st Med. Dept. Hanusch Hospital, 1140 Vienna, Austria
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17
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Taylan F, Yavaş Abalı Z, Jäntti N, Güneş N, Darendeliler F, Baş F, Poyrazoğlu Ş, Tamçelik N, Tüysüz B, Mäkitie O. Two novel mutations in XYLT2 cause spondyloocular syndrome. Am J Med Genet A 2017; 173:3195-3200. [PMID: 28884924 DOI: 10.1002/ajmg.a.38470] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Revised: 08/12/2017] [Accepted: 08/12/2017] [Indexed: 01/24/2023]
Abstract
We report on two new patients with spondyloocular syndrome. Both patients harbor novel homozygous mutations in the XYLT2 gene. The patients present severe generalized osteoporosis, multiple fractures, short stature, cataract, and mild hearing impairment. XYLT2 mutations have been identified in spondyloocular syndrome, however only five mutations have been reported previously. These two patients with novel mutations extend the phenotypic and genotypic spectrum of spondyloocular syndrome.
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Affiliation(s)
- Fulya Taylan
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Zehra Yavaş Abalı
- Department of Pediatric Endocrinology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Nina Jäntti
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
| | - Nilay Güneş
- Department of Pediatric Genetics, Cerrahpasa Medicine School, Istanbul University, Istanbul, Turkey
| | - Feyza Darendeliler
- Department of Pediatric Endocrinology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Firdevs Baş
- Department of Pediatric Endocrinology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Şükran Poyrazoğlu
- Department of Pediatric Endocrinology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Nevbahar Tamçelik
- Department of Ophthalmology, Cerrahpasa Medicine School, Istanbul University, Istanbul, Turkey
| | - Beyhan Tüysüz
- Department of Pediatric Genetics, Cerrahpasa Medicine School, Istanbul University, Istanbul, Turkey
| | - Outi Mäkitie
- Department of Molecular Medicine and Surgery, Center for Molecular Medicine, Karolinska Institute, Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
- Folkhälsan Institute of Genetics, Helsinki, Finland
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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18
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Kämpe AJ, Costantini A, Levy-Shraga Y, Zeitlin L, Roschger P, Taylan F, Lindstrand A, Paschalis EP, Gamsjaeger S, Raas-Rothschild A, Hövel M, Jiao H, Klaushofer K, Grasemann C, Mäkitie O. PLS3 Deletions Lead to Severe Spinal Osteoporosis and Disturbed Bone Matrix Mineralization. J Bone Miner Res 2017; 32:2394-2404. [PMID: 28777485 DOI: 10.1002/jbmr.3233] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 07/25/2017] [Accepted: 08/02/2017] [Indexed: 01/19/2023]
Abstract
Mutations in the PLS3 gene, encoding Plastin 3, were described in 2013 as a cause for X-linked primary bone fragility in children. The specific role of PLS3 in bone metabolism remains inadequately understood. Here we describe for the first time PLS3 deletions as the underlying cause for childhood-onset primary osteoporosis in 3 boys from 2 families. We carried out thorough clinical, radiological, and bone tissue analyses to explore the consequences of these deletions and to further elucidate the role of PLS3 in bone homeostasis. In family 1, the 2 affected brothers had a deletion of exons 4-16 (NM_005032) in PLS3, inherited from their healthy mother. In family 2, the index patient had a deletion involving the entire PLS3 gene (exons 1-16), inherited from his mother who had osteoporosis. The 3 patients presented in early childhood with severe spinal compression fractures involving all vertebral bodies. The 2 brothers in family 1 also displayed subtle dysmorphic facial features and both had developed a myopathic gait. Extensive analyses of a transiliac bone biopsy from 1 patient showed a prominent increase in osteoid volume, osteoid thickness, and in mineralizing lag time. Results from quantitative backscattered electron imaging and Raman microspectroscopy showed a significant hypomineralization of the bone. Together our results indicate that PLS3 deletions lead to severe childhood-onset osteoporosis resulting from defective bone matrix mineralization, suggesting a specific role for PLS3 in the mineralization process. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Anders J Kämpe
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Alice Costantini
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Yael Levy-Shraga
- Pediatric Endocrinology Unit, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Leonid Zeitlin
- Pediatric Orthopedic Department, Dana-Dwek Children's Hospital, Tel Aviv Sourasly Medical Center, Tel Aviv, Israel
| | - Paul Roschger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Fulya Taylan
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Anna Lindstrand
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
| | - Eleftherios P Paschalis
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Sonja Gamsjaeger
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Annick Raas-Rothschild
- Institute for Rare Diseases, The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel-Hashomer, Israel
| | - Matthias Hövel
- Department of Orthopedics and Trauma Surgery, University Hospital Essen and the University of Duisburg-Essen, Essen, Germany
| | - Hong Jiao
- Department of Biosciences and Nutrition, and Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Klaus Klaushofer
- Ludwig Boltzmann Institute of Osteology at the Hanusch Hospital of WGKK and AUVA Trauma Centre Meidling, 1st Medical Department, Hanusch Hospital, Vienna, Austria
| | - Corinna Grasemann
- Klinik für Kinderheilkunde II, University Hospital Essen and the University of Duisburg-Essen, Essen, Germany
| | - Outi Mäkitie
- Department of Molecular Medicine and Surgery and Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden.,Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
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19
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Kämpe AJ, Costantini A, Mäkitie RE, Jäntti N, Valta H, Mäyränpää M, Kröger H, Pekkinen M, Taylan F, Jiao H, Mäkitie O. PLS3 sequencing in childhood-onset primary osteoporosis identifies two novel disease-causing variants. Osteoporos Int 2017; 28:3023-3032. [PMID: 28748388 PMCID: PMC5624974 DOI: 10.1007/s00198-017-4150-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 07/06/2017] [Indexed: 12/12/2022]
Abstract
UNLABELLED Altogether 95 children with primary bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Two children with multiple peripheral and spinal fractures and low BMD had novel disease-causing PLS3 variants. Children with milder phenotypes had no pathogenic variants. PLS3 screening is indicated in childhood-onset primary osteoporosis. INTRODUCTION The study aimed to determine the role of pathogenic PLS3 variants in children's bone fragility and to elucidate the associated phenotypic features. METHODS Two cohorts of children with bone fragility were screened for variants in PLS3, the gene underlying X-linked osteoporosis. Cohort I comprised 31 patients with childhood-onset primary osteoporosis of unknown etiology. Cohort II comprised 64 children who had sustained multiple fractures but were otherwise healthy. Clinical and radiological data were reviewed. Peripheral blood DNA was Sanger sequenced for coding exons and flanking intronic regions of PLS3. RESULTS In two patients of cohort I, where other common genetic causes had been excluded, we identified two novel disease-causing PLS3 variants. Patient 1 was a male with bilateral femoral fractures at 10 years, low BMD (Z-score -4.1; 18 years), and multiple vertebral compression fractures. He had a novel nonsense variant in PLS3. Patient 2 was a girl with multiple long bone and vertebral fractures and low BMD (Z-score -6.6 at 6 years). She had a de novo missense variant in PLS3; whole exome sequencing and array-CGH identified no other genetic causes. Iliac crest bone biopsies confirmed low-turnover osteoporosis in both patients. In cohort II, no pathogenic PLS3 variants were identified in any of the subjects. CONCLUSIONS Two novel disease-causing variants in PLS3 were identified in a boy and a girl with multiple peripheral and spinal fractures and very low BMD while no pathogenic variants were identified in children with less severe skeletal fragility. PLS3 screening is warranted in male and female patients with childhood-onset primary osteoporosis.
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Affiliation(s)
- A J Kämpe
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden.
| | - A Costantini
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - R E Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
| | - N Jäntti
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - H Valta
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - M Mäyränpää
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - H Kröger
- Department of Orthopaedics and Traumatology, Bone and Cartilage Research Unit, Kuopio University Hospital and University of Eastern Finland, Kuopio, Finland
| | - M Pekkinen
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
| | - F Taylan
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - H Jiao
- Department of Biosciences and Nutrition and Science for Life Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - O Mäkitie
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
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Wesseling-Perry K, Mäkitie RE, Välimäki VV, Laine T, Laine CM, Välimäki MJ, Pereira RC, Mäkitie O. Osteocyte Protein Expression Is Altered in Low-Turnover Osteoporosis Caused by Mutations in WNT1 and PLS3. J Clin Endocrinol Metab 2017; 102:2340-2348. [PMID: 28379384 PMCID: PMC5505188 DOI: 10.1210/jc.2017-00099] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 03/29/2017] [Indexed: 01/20/2023]
Abstract
CONTEXT Osteocytes express proteins that regulate bone remodeling and mineralization. OBJECTIVE To evaluate the relationship between osteocyte-specific protein expression and bone histology in patients with monogenic osteoporosis due to wingless integration site 1 (WNT1) or plastin 3 (PLS3) mutations. DESIGN AND SETTING Cross-sectional cohort study at a university hospital. PARTICIPANTS Six patients (four males; ages: 14 to 72 years) with a heterozygous WNT1 mutation and five patients (four males; ages: 9 to 70 years) with a heterozygous/hemizygous PLS3 mutation. METHODS AND MAIN OUTCOME MEASURES Immunohistochemistry was performed for fibroblast growth factor 23 (FGF23), dentin matrix protein 1 (DMP1), sclerostin, and phosphorylated (phospho-)β-catenin in iliac crest samples and compared with bone histomorphometry. RESULTS FGF23 expression in WNT1 patients was 243% that observed in PLS3 patients (P < 0.01). DMP1, sclerostin, and phospho-β-catenin expression did not differ between groups. Serum phosphate correlated inversely with FGF23 expression (r = -0.79, P = 0.01) and serum ionized calcium correlated inversely with sclerostin expression (r = -0.60, P = 0.05). Phospho-β-catenin expression correlated inversely with DMP1 expression (r = -0.88, P < 0.001), osteoid volume/bone volume (r = -0.68, P = 0.02), and bone formation rate (r = -0.78, P < 0.01). FGF23 expression did not correlate with DMP1 expression, sclerostin expression, or bone histomorphometry. Marrow adiposity was higher in WNT1 than in PLS3 patients (P = 0.04). CONCLUSIONS Mutations that disrupt WNT signaling and osteocytic mechanosensing affect osteocyte protein expression. Abnormal osteocyte function may play a role in the pathogenesis of monogenetic forms of osteoporosis.
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Affiliation(s)
- Katherine Wesseling-Perry
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Riikka E. Mäkitie
- Folkhälsan Institute of Genetics, University of Helsinki, 00014 Helsinki, Finland
| | - Ville-Valtteri Välimäki
- Department of Orthopedics and Traumatology, Helsinki University Central Hospital and Helsinki University, Jorvi Hospital, 02740 Espoo, Finland
| | - Tero Laine
- Department of Orthopedics, Institute of Clinical Sciences, Sahlgrenska University Hospital and University of Gothenburg, 41345 Gothenburg, Sweden
| | - Christine M. Laine
- Children’s Hospital, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, Finland
- Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital and University of Gothenburg, 41345 Gothenburg, Sweden
| | - Matti J. Välimäki
- Division of Endocrinology, Department of Medicine, Helsinki University Central Hospital, 00029 Helsinki, Finland
| | - Renata C. Pereira
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics, University of Helsinki, 00014 Helsinki, Finland
- Children’s Hospital, University of Helsinki and Helsinki University Hospital, 00014 Helsinki, Finland
- Department of Molecular Medicine and Surgery, Karolinska Institutet, 17176 Stockholm, Sweden
- Department of Clinical Genetics, Karolinska University Hospital, 17176 Stockholm, Sweden
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Mäkitie RE, Haanpää M, Valta H, Pekkinen M, Laine CM, Lehesjoki AE, Schalin-Jäntti C, Mäkitie O. Skeletal Characteristics of WNT1 Osteoporosis in Children and Young Adults. J Bone Miner Res 2016; 31:1734-42. [PMID: 27005318 DOI: 10.1002/jbmr.2841] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Revised: 03/13/2016] [Accepted: 03/20/2016] [Indexed: 12/22/2022]
Abstract
WNT proteins comprise a 19-member glycoprotein family that act in several developmental and regenerative processes. In bone, WNT proteins regulate osteoblast differentiation and maintain bone health by activating the canonical WNT/β-catenin pathway. We reported a heterozygous missense mutation c.652T>G (p.C218G) in WNT1 exon 4 as the cause for severe early-onset, autosomal dominant osteoporosis. The initial study concerned a large Finnish family with 10 affected adults. Here we report clinical findings of the WNT1 osteoporosis in 8 children and young adults (median age 14 years; range 10 to 30 years) in two families, all with the p.C218G mutation in WNT1. Clinical assessments showed no apparent dysmorphia or features similar to typical osteogenesis imperfecta (OI). Biochemistry revealed no changes in parameters of calcium metabolism and bone turnover markers. Fracture frequencies varied, but all subjects had sustained at least one fracture and 4 had a pathological fracture history. Plain radiographs showed osteopenic appearance, loss in vertebral height, and thin diaphyses of the long bones. Bone densitometry showed the BMD to be below normal median in all subjects and the bone mass deficit seemed to be more severe in older participants. Bone histomorphometry revealed a low turnover osteoporosis in 2 subjects at ages 14 and 16 years. These findings are congruent with earlier findings in adult patients and indicate that WNT1 osteoporosis causes significant skeletal changes already in early childhood and impairs bone mass gain during pubertal years. Genetic testing of children or close relatives of affected individuals is recommended for appropriate preventive measures. © 2016 American Society for Bone and Mineral Research.
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Affiliation(s)
- Riikka E Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
| | - Maria Haanpää
- Department of Clinical Genetics, Turku University Hospital, Turku, Finland
| | - Helena Valta
- Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Minna Pekkinen
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland
| | - Christine M Laine
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland.,Department of Endocrinology, Institute of Medicine, Sahlgrenska University Hospital and University of Gothenburg, Gothenburg, Sweden
| | | | - Camilla Schalin-Jäntti
- Endocrinology, Abdominal Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Outi Mäkitie
- Folkhälsan Institute of Genetics and University of Helsinki, Helsinki, Finland.,Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Center for Molecular Medicine, Karolinska Institutet, and Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
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