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Dahir KM, Rush ET, Diaz-Mendoza S, Kishnani PS. A Delphi panel to build consensus on assessing disease severity and disease progression in adult patients with hypophosphatasia in the United States. J Endocrinol Invest 2024; 47:1487-1497. [PMID: 38236379 PMCID: PMC11142979 DOI: 10.1007/s40618-023-02256-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/21/2023] [Indexed: 01/19/2024]
Abstract
BACKGROUND Hypophosphatasia (HPP) is an inborn error of metabolism with a variable presentation. We conducted a modified Delphi panel to obtain expert consensus on knowledge gaps regarding disease severity and progression in adult patients with HPP. METHODS Healthcare professionals (HCPs) with experience managing adult patients with HPP were recruited to participate in a 3-round Delphi panel (round 1: paper survey and 1:1 interview; rounds 2-3: email survey). Panelists rated the extent of their agreement with statements about disease severity and progression in adult patients with HPP. Consensus was defined as ≥ 80% agreement. RESULTS Ten HCPs completed round 1; nine completed rounds 2 and 3. Consensus was reached on 46/120 statements derived from steering committee input. Disease severity markers in adult patients with HPP can be bone-related (recurrent/poorly healing fractures, pseudo-fractures, metatarsal fractures, osteomalacia) or involve dentition or physiologic/functional manifestations (use of mobility devices/home modifications, abnormal gait, pain). Disease progression markers can include recurrent/poorly healing low-trauma fractures, development of ectopic calcifications, and/or impairment of functional activity. Panelists supported the development of a tool to help assess disease severity in the clinic and track changes in severity over time. Panelists also highlighted the role of a multidisciplinary team, centers with expertise, and the need to refer patients when disease severity is not clear. CONCLUSIONS These statements regarding disease severity, progression, and assessment methods address some knowledge gaps in adult patients with HPP and may be helpful for treating HCPs, although the small sample size affects the ability to generalize the healthcare provider experience.
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Affiliation(s)
- K M Dahir
- Division of Endocrinology and Metabolism, Vanderbilt University Medical Center, 1215 21st Ave S Suite 8210, Nashville, TN, 37232, USA.
| | - E T Rush
- Division of Clinical Genetics, Children's Mercy Kansas City, 2401 Gillham Rd, Kansas City, MO, 64108, USA.
- Department of Pediatrics, University of Missouri-Kansas City School of Medicine, Kansas City, MO, USA.
- Department of Internal Medicine, University of Kansas School of Medicine, Kansas City, KS, USA.
| | | | - P S Kishnani
- Division of Medical Genetics, Department of Pediatrics, Duke University School of Medicine, Durham, NC, USA
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2
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Fraga G, Herreros MA, Pybus M, Aza-Carmona M, Pilco-Teran M, Furlano M, García-Borau MJ, Torra R, Ars E. A Mild Presentation of X-Linked Hypophosphatemia Caused by a Non-Canonical Splice Site Variant in the PHEX Gene. Genes (Basel) 2024; 15:679. [PMID: 38927615 PMCID: PMC11202505 DOI: 10.3390/genes15060679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/17/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare inherited disorder of renal phosphate wasting with a highly variable phenotype caused by loss-of-function variants in the PHEX gene. The diagnosis of individuals with mild phenotypes can be challenging and often delayed. Here, we describe a three-generation family with a very mild clinical presentation of XLH. The diagnosis was unexpectedly found in a 39-year-old woman who was referred for genetic testing due to an unclear childhood diagnosis of a tubulopathy. Genetic testing performed by next-generation sequencing using a kidney disease gene panel identified a novel non-canonical splice site variant in the PHEX gene. Segregation analysis detected that the consultand's father, who presented with hypophosphatemia and decreased tubular phosphate reabsorption, and the consultand's son also carried this variant. RNA studies demonstrated that the non-canonical splice site variant partially altered the splicing of the PHEX gene, as both wild-type and aberrant splicing transcripts were detected in the two male members with only one copy of the PHEX gene. In conclusion, this case contributes to the understanding of the relationship between splicing variants and the variable expressivity of XLH disease. The mild phenotype of this family can be explained by the coexistence of PHEX transcripts with aberrant and wild-type splicing.
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Affiliation(s)
- Gloria Fraga
- Pediatric Nephrology Department, Hospital de la Santa Creu i Sant Pau, Institut de Recerca Sant Pau (IR Sant Pau), RICORS-SAMID, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain;
| | - M. Alba Herreros
- Nephrology Department, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - Marc Pybus
- Molecular Biology Laboratory, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), 08193 Barcelona, Catalonia, Spain
| | - Miriam Aza-Carmona
- Molecular Biology Laboratory, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), 08193 Barcelona, Catalonia, Spain
| | - Melissa Pilco-Teran
- Nephrology Department, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - Mónica Furlano
- Nephrology Department, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - M. José García-Borau
- Neonatology Unit, Pediatrics Department, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - Roser Torra
- Nephrology Department, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), Department of Medicine, Universitat Autònoma de Barcelona, 08193 Barcelona, Catalonia, Spain
| | - Elisabet Ars
- Molecular Biology Laboratory, Fundació Puigvert, Institut de Recerca Sant Pau (IR-Sant Pau), RICORS2040 (Kidney Disease), 08193 Barcelona, Catalonia, Spain
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3
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Baroncelli GI, Comberiati P, Aversa T, Baronio F, Cassio A, Chiarito M, Cosci o di Coscio M, De Sanctis L, Di Iorgi N, Faienza MF, Fintini D, Franceschi R, Kalapurackal M, Longhi S, Mariani M, Pitea M, Secco A, Tessaris D, Vierucci F, Wasniewska M, Weber G, Mora S. Diagnosis, treatment, and management of rickets: a position statement from the Bone and Mineral Metabolism Group of the Italian Society of Pediatric Endocrinology and Diabetology. Front Endocrinol (Lausanne) 2024; 15:1383681. [PMID: 38706696 PMCID: PMC11066174 DOI: 10.3389/fendo.2024.1383681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 04/03/2024] [Indexed: 05/07/2024] Open
Abstract
Rickets results from impaired mineralization of growing bone due to alterations in calcium and phosphate homeostasis. Clinical signs of rickets are related to the age of the patient, the duration of the disease, and the underlying disorder. The most common signs of rickets are swelling of the wrists, knees or ankles, bowing of the legs (knock-knees, outward bowing, or both) and inability to walk. However, clinical features alone cannot differentiate between the various forms of rickets. Rickets includes a heterogeneous group of acquired and inherited diseases. Nutritional rickets is due to a deficiency of vitamin D, dietary calcium or phosphate. Mutations in genes responsible for vitamin D metabolism or function, the production or breakdown of fibroblast growth factor 23, renal phosphate regulation, or bone mineralization can lead to the hereditary form of rickets. This position paper reviews the relevant literature and presents the expertise of the Bone and Mineral Metabolism Group of the Italian Society of Pediatric Endocrinology and Diabetology (SIEDP). The aim of this document is to provide practical guidance to specialists and healthcare professionals on the main criteria for diagnosis, treatment, and management of patients with rickets. The various forms of rickets are discussed, and detailed references for the discussion of each form are provided. Algorithms to guide the diagnostic approach and recommendations to manage patients with rare forms of hereditary rickets are proposed.
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Affiliation(s)
- Giampiero I. Baroncelli
- Pediatric and Adolescent Endocrinology, Division of Pediatrics, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
| | - Pasquale Comberiati
- Pediatric and Adolescent Endocrinology, Division of Pediatrics, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
- Department of Clinical and Experimental Medicine, Section of Paediatrics, University of Pisa, Pisa, Italy
| | - Tommaso Aversa
- Department of Human Pathology of Adulthood and Childhood, University of Messina, Messina, Italy
- Pediatric Unit, University Hospital “G. Martino”, Messina, Italy
| | - Federico Baronio
- Pediatric Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Alessandra Cassio
- Pediatric Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
- Department of Medical and Surgical Sciences, University of Bologna, Bologna, Italy
| | - Mariangela Chiarito
- Pediatric Unit, Department of Precision and Regenerative Medicine and Ionian Area, University “A. Moro” of Bari, Bari, Italy
| | - Mirna Cosci o di Coscio
- Pediatric and Adolescent Endocrinology, Division of Pediatrics, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
| | - Luisa De Sanctis
- Division of Pediatric Endocrinology, Department of Public Health and Pediatrics, University of Turin, Regina Margherita Children’s Hospital, Turin, Italy
| | - Natascia Di Iorgi
- Department of Pediatrics, IRCCS Istituto Giannina Gaslini, Genova, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Maria Felicia Faienza
- Pediatric Unit, Department of Precision and Regenerative Medicine and Ionian Area, University “A. Moro” of Bari, Bari, Italy
| | - Danilo Fintini
- Endocrinology and Diabetology Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Roberto Franceschi
- Department of Pediatrics, Santa Chiara Hospital of Trento, APSS, Trento, Italy
| | - Mila Kalapurackal
- Department of Pediatrics, Hospital of Bolzano (SABES-ASDAA), Teaching Hospital of Paracelsus Medical University (PMU), Bolzano, Italy
| | - Silvia Longhi
- Department of Pediatrics, Hospital of Bolzano (SABES-ASDAA), Teaching Hospital of Paracelsus Medical University (PMU), Bolzano, Italy
| | - Michela Mariani
- Endocrinology and Diabetology Unit, Bambino Gesù Children Hospital, IRCCS, Rome, Italy
| | - Marco Pitea
- Pediatric Endocrinology Unit, Department of Pediatrics, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Andrea Secco
- Pediatric and Pediatric Emergency Unit, Children Hospital, Azienda Ospedaliera SS Antonio e Biagio e C. Arrigo, Alessandria, Italy
| | - Daniele Tessaris
- Division of Pediatric Endocrinology, Department of Public Health and Pediatrics, University of Turin, Regina Margherita Children’s Hospital, Turin, Italy
| | | | - Malgorzata Wasniewska
- Department of Human Pathology of Adulthood and Childhood, University of Messina, Messina, Italy
| | - Giovanna Weber
- Pediatric Endocrinology Unit, Department of Pediatrics, IRCCS Ospedale San Raffaele, Milan, Italy
| | - Stefano Mora
- Laboratory of Pediatric Endocrinology, Department of Pediatrics, IRCCS Ospedale San Raffaele, Milan, Italy
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4
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Charles JF, Malabanan AO, Krolczyk S, Dahir KM. Rare Causes of Musculoskeletal Pain: Thinking beyond Common Rheumatologic Diseases. Case Rep Rheumatol 2024; 2024:6540026. [PMID: 38283708 PMCID: PMC10810688 DOI: 10.1155/2024/6540026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Revised: 01/06/2024] [Accepted: 01/09/2024] [Indexed: 01/30/2024] Open
Abstract
Objectives Rare metabolic bone diseases can present with symptoms mimicking more common rheumatological conditions including spondyloarthritis, osteoarthritis, and fibromyalgia. Increasing awareness of these rare diseases within the rheumatology community is vital to ensure that affected patients are diagnosed and appropriately treated. The literature includes several reports of tumour-induced osteomalacia initially diagnosed as rheumatic disease, but other rare diseases such as X-linked hypophosphatemia (XLH) and hypophosphatasia (HPP) also deserve attention. Here, we describe two cases of adult patients incorrectly diagnosed with ankylosing spondylitis and osteoarthritis who, upon referral to a metabolic bone disease specialist, were subsequently diagnosed with XLH and HPP, respectively, profoundly altering their management. Methods The cases were collected from Brigham and Women's Hospital, Boston, MA, USA, and Vanderbilt University Medical Center, Nashville, TN, USA. Results Details of the patients' respective medical and family histories are presented, and the clinical and biochemical investigations undertaken to reach the correct diagnoses are described. Conclusion Rheumatologists should be encouraged to think beyond common rheumatological diseases when faced with symptoms such as bone pain, muscle pain, and stiffness, especially when accompanied by manifestations including atraumatic fractures, poor dentition, and hearing loss. In cases where one of these rare diseases is suspected, referral to a metabolic bone disease specialist for confirmation of diagnosis is encouraged as effective treatment options have recently become available.
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Affiliation(s)
- Julia F. Charles
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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5
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Ward LM, Högler W, Glorieux FH, Portale AA, Whyte MP, Munns CF, Nilsson O, Simmons JH, Padidela R, Namba N, Cheong HI, Sochett E, Muroya K, Tanaka H, Pitukcheewanont P, Gottesman GS, Biggin A, Perwad F, Chen A, Lawrence Merritt II J, Imel EA. Burosumab vs conventional therapy in children with X-linked hypophosphatemia: results of the open-label, phase 3 extension period. JBMR Plus 2024; 8:ziad001. [PMID: 38690124 PMCID: PMC11059996 DOI: 10.1093/jbmrpl/ziad001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/06/2023] [Indexed: 05/02/2024] Open
Abstract
In a randomized, open-label phase 3 study of 61 children aged 1-12 years old with X-linked hypophosphatemia (XLH) previously treated with conventional therapy, changing to burosumab every 2 weeks (Q2W) for 64 weeks improved the phosphate metabolism, radiographic rickets, and growth compared with conventional therapy. In this open-label extension period (weeks 64-88), 21 children continued burosumab Q2W at the previous dose or crossed over from conventional therapy to burosumab starting at 0.8 mg/kg Q2W with continued clinical radiographic assessments through week 88. Efficacy endpoints and safety observations were summarized descriptively for both groups (burosumab continuation, n = 6; crossover, n = 15). At week 88 compared with baseline, improvements in the following outcomes were observed in the burosumab continuation and crossover groups, respectively: mean (SD) RGI-C rickets total score (primary outcome), +2.11 (0.27) and +1.89 (0.35); mean (SD) RGI-C lower limb deformity score, +1.61 (0.91) and +0.73 (0.82); and mean (SD) height Z-score + 0.41 (0.50) and +0.08 (0.34). Phosphate metabolism normalized rapidly in the crossover group and persisted in the continuation group. Mean (SD) serum alkaline phosphatase decreased from 169% (43%) of the upper limit of normal (ULN) at baseline to 126% (51%) at week 88 in the continuation group and from 157% (33%) of the ULN at baseline to 111% (23%) at week 88 in the crossover group. During the extension period, treatment-emergent adverse events (AEs) were reported in all 6 children in the burosumab continuation group and 14/15 children in the crossover group. The AE profiles in the randomized and extension periods were similar, with no new safety signals identified. Improvements from baseline in radiographic rickets continued in the extension period among children with XLH who remained on burosumab. Children who crossed over from conventional therapy to burosumab demonstrated a rapid improvement in phosphate metabolism and improved rickets healing over the ensuing 22 weeks.
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Affiliation(s)
- Leanne M Ward
- Department of Pediatrics, Faculty of Medicine, University of Ottawa, Ottawa, Ontario, K1H 8L1, Canada
| | - Wolfgang Högler
- Department of Paediatrics and Adolescent Medicine, Johannes Kepler University Linz, 4040 Linz, Austria
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, Birmingham, B15 2TT, United Kingdom
| | - Francis H Glorieux
- Department of Surgery, Pediatrics, and Human Genetics, Shriners Hospitals for Children and McGill University, Montreal, Quebec, H4A 0A9, Canada
| | - Anthony A Portale
- Department of Pediatrics, University of California, San Francisco, CA, 94158, United States
| | - Michael P Whyte
- Shriners Hospitals for Children St Louis, St Louis, MO, 63110, United States
| | - Craig F Munns
- Faculty of Medicine, The University of Queensland, Brisbane, Queensland, 4072, Australia
- Faculty of Medicine, Child Health Research Centre, The University of Queensland, Brisbane, Queensland, 4072, Australia
- Department of Endocrinology and Diabetes, Queensland Children’s Hospital, Brisbane, Queensland, 4072, Australia
| | - Ola Nilsson
- Division of Pediatric Endocrinology, Department of Women’s and Children’s Health, Center for Molecular Medicine, Karolinska Institutet and University Hospital, SE-17176 Stockholm, Sweden
- Department of Pediatrics, School of Medical Sciences, Örebro University and University Hospital, S-701 82 Örebro, Sweden
| | - Jill H Simmons
- Division of Endocrinology and Diabetes, Department of Pediatrics, Vanderbilt University School of Medicine, Vanderbilt University, Nashville, TN, 37232, United States
| | - Raja Padidela
- Department of Paediatric Endocrinology, Royal Manchester Children’s Hospital, Manchester, M13 9WL, United Kingdom
| | - Noriyuki Namba
- Department of Pediatrics, Osaka Hospital, Japan Community Healthcare Organization, Osaka, 553-0003, Japan
- Osaka University Graduate School of Medicine, Osaka, 565-0871, Japan
| | - Hae Il Cheong
- Department of Pediatrics, Hallym University Sacred Heart Hospital, Dongan-gu, Anyang, 14068, South Korea
| | - Etienne Sochett
- Department of Pediatrics, Hospital for Sick Children, Toronto, Ontario, M5G 1E8, Canada
| | - Koji Muroya
- Department of Endocrinology, Kanagawa Children’s Medical Center, Yokohama, Kanagawa 232-0066, Japan
| | - Hiroyuki Tanaka
- Division of Pediatrics, Okayama Saiseikai General Hospital Outpatient Center, Kita-ku, Okayama, 700-8511, Japan
| | - Pisit Pitukcheewanont
- Center of Endocrinology, Diabetes and Metabolism, Children’s Hospital of Los Angeles, Los Angeles, CA, 90027, United States
| | - Gary S Gottesman
- Shriners Hospitals for Children St Louis, St Louis, MO, 63110, United States
| | - Andrew Biggin
- Department of Endocrinology, The University of Sydney Children’s Hospital Westmead Clinical School, The Children’s Hospital at Westmead, Westmead, New South Wales, 2145, Australia
| | - Farzana Perwad
- Department of Pediatrics, University of California, San Francisco, CA, 94158, United States
| | - Angel Chen
- Ultragenyx Pharmaceutical Inc., Novato, CA, 94949, United States
| | | | - Erik A Imel
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, United States
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Abdullah A, Wuersching SN, Kollmuss M, Poxleitner P, Dewenter I, Brandenburg LS, Steybe D, Fegg FN, Smolka W, Otto S, Obermeier KT. X-Linked Hypophosphatemia: Does Targeted Therapy Modify Dental Impairment? J Clin Med 2023; 12:7546. [PMID: 38137614 PMCID: PMC10744150 DOI: 10.3390/jcm12247546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/22/2023] [Accepted: 12/04/2023] [Indexed: 12/24/2023] Open
Abstract
X-linked hypophosphatemia is a rare, hereditary disorder that significant influences teeth and alveolar bone. The first clinical sign leading to the diagnosis of X-linked hypophosphatemia is often dental impairment with dental abscesses and dentin mineralization defects. Genetic analysis helped find the responsible gene and therefore opened up new ways of therapeutically managing X-linked hypophosphatemia. The human monoclonal antibody Burosumab represents a milestone in the targeted therapy of this hereditary disease by directly addressing its pathophysiology. Targeted therapy has been shown to improve skeletal impairment, pain, and phosphate metabolism. However, the influence of this new therapy on dental impairment has only been addressed in a few recent studies with varying results. Therefore, in this review, we aim to summarize the dental phenotype and analyze the different treatment modalities with a focus on dental impairment.
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Affiliation(s)
- Anusha Abdullah
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Sabina Noreen Wuersching
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestrasse 70, 80336 Munich, Germany
| | - Maximilian Kollmuss
- Department of Conservative Dentistry and Periodontology, University Hospital, LMU Munich, Goethestrasse 70, 80336 Munich, Germany
| | - Philipp Poxleitner
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Ina Dewenter
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Leonard Simon Brandenburg
- Medical Center—University of Freiburg, Center for Dental Medicine, Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106 Freiburg, Germany
| | - David Steybe
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Florian Nepomuk Fegg
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Wenko Smolka
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Sven Otto
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
| | - Katharina Theresa Obermeier
- Department of Oral and Maxillofacial Surgery and Facial Plastic Surgery, Ludwig Maximilians University, 80337 Munich, Germany
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7
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Seefried L, Alzahrani A, Arango Sancho P, Bacchetta J, Crowley R, Emma F, Gibbins J, Grandone A, Javaid MK, Mindler G, Raimann A, Rothenbuhler A, Tucker I, Zeitlin L, Linglart A. XLH Matters 2022: Insights and recommendations to improve outcomes for people living with X-linked hypophosphataemia (XLH). Orphanet J Rare Dis 2023; 18:333. [PMID: 37885021 PMCID: PMC10604503 DOI: 10.1186/s13023-023-02883-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023] Open
Affiliation(s)
- Lothar Seefried
- Orthopedic Institute, König-Ludwig Haus, University of Würzburg, Würzburg, Germany
| | - Ali Alzahrani
- King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Pedro Arango Sancho
- Department of Pediatric Nephrology, Hospital Sant Joan de Déu, Barcelona, Spain
- Department of Onco-Nephrology, Pediatric Cancer Center, Barcelona, Spain
| | - Justine Bacchetta
- Pediatric Nephrology, Reference Center for Rare Diseases of Calcium and Phosphate, Filières OSCAR et ORKID, INSERM1033, Hospices Civils de Lyon, Lyon, France
| | - Rachel Crowley
- St Vincent's University Hospital and Rare Disease Clinical Trial Network, University College Dublin, Dublin, Ireland
| | - Francesco Emma
- Division of Nephrology, Children's Hospital Bambino Gesù-IRCCS, Rome, Italy
| | | | - Anna Grandone
- Department of Woman, Child, General and Specialized Surgery, University of Campania L. Vanvitelli, Naples, Italy
| | - Muhammad Kassim Javaid
- Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, UK
| | - Gabriel Mindler
- Department of Pediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | | | - Anya Rothenbuhler
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR, Paris, France
- APHP, Platform of Expertise for Rare Disorders Paris Saclay, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France
| | - Ian Tucker
- Bristol Royal Hospital for Children, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, UK
| | - Leonid Zeitlin
- Pediatric Bone Clinic, Orthopedic Department, Dana-Dwek Children's Hospital, Tel-Aviv Medical Center, Tel Aviv-Yafo, Israel
| | - Agnès Linglart
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France.
- APHP, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR, Paris, France.
- APHP, Platform of Expertise for Rare Disorders Paris Saclay, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France.
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8
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Abdullah SJ, Mahwi TO, Mohamad Salih Saeed A, Abdulateef DS, Rahman HS, Ahmed SF, Abdulqader SA. X-Linked Familial Hypophosphatemia: A Case Report of 27-Year Old Male and Review of Literature. Horm Metab Res 2023; 55:653-664. [PMID: 37813097 PMCID: PMC10562047 DOI: 10.1055/a-2159-8429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 08/15/2023] [Indexed: 10/11/2023]
Abstract
X-linked hypophosphatemia (XLH) associated with short stature during childhood are mostly referred to the hospital and diagnosed as vitamin D deficiency rickets and received vitamin D before adulthood. A case is presented with clinical features of hypophosphatemia from childhood who did not seek medical care for diagnosis and treatment, nor did his mother or two brothers, who have short statures, bone pain, and fractures. The patient was assessed for sociodemographic, hematological, and biochemical parameters together with a genetic assessment. A DEXA scan and X-ray were done to determine the abnormalities and deformities of joints and bones despite clinical examination by an expert physician. All imaging, laboratory parameters, and the genetic study confirmed the diagnosis of XLH. A detailed follow-up of his condition was performed after the use of phosphate tablets and other treatments. X-linked hypophosphatemia needs a good assessment, care, and follow up through a complementary medical team including several specialties. Phosphate tablets in adulthood significantly affects clinical and physical improvement and prevention of further skeletal abnormality and burden on daily activity. The patients should be maintained with an adequate dose of phosphate for better patient compliance. More awareness is needed in society and for health professionals when conducting medical checkups during the presence of stress fractures, frequent dental and gum problems, rickets, short stature, or abnormality in the skeleton or walking to think of secondary causes such as hypophosphatemia. Further investigations including a visit to a specialist is imperative to check for the primary cause of these disturbances.
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Affiliation(s)
| | - Taha Othman Mahwi
- Medicine, University of Sulaimani College of Medicine, Sulaymaniyah,
Kurdistan region, Iraq
| | | | - Darya Saeed Abdulateef
- Medical Education, University of Sulaimani College of Medicine,
Sulaymaniyah, Kurdistan region, Iraq
| | - Heshu Sulaiman Rahman
- Physiology, University of Sulaimani College of Medicine, Sulaymaniyah,
Kurdistan region, Iraq
| | - Shaho Fatah Ahmed
- Endocrine Unit, Internal Medicine, Shar Hospital, Sulaymaniyah,
Kurdistan region, Iraq
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Arboleya L, Braña I, Pardo E, Loredo M, Queiro R. Osteomalacia in Adults: A Practical Insight for Clinicians. J Clin Med 2023; 12:jcm12072714. [PMID: 37048797 PMCID: PMC10094844 DOI: 10.3390/jcm12072714] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 03/26/2023] [Accepted: 04/01/2023] [Indexed: 04/14/2023] Open
Abstract
The term osteomalacia (OM) refers to a series of processes characterized by altered mineralization of the skeleton, which can be caused by various disorders of mineral metabolism. OM can be genetically determined or occur due to acquired disorders, among which the nutritional origin is particularly relevant, due to its wide epidemiological extension and its nature as a preventable disease. Among the hereditary diseases associated with OM, the most relevant is X-linked hypophosphatemia (XLH), which manifests in childhood, although its consequences persist into adulthood where it can acquire specific clinical characteristics, and, although rare, there are XLH cases that reach the third or fourth decade of life without a diagnosis. Some forms of OM present very subtle initial manifestations which cause both considerable diagnosis and treatment delay. On occasions, the presence of osteopenia and fragility fractures leads to an erroneous diagnosis of osteoporosis, which may imply the prescription of antiresorptive drugs (i.e., bisphosphonates or denosumab) with catastrophic consequences for OM bone. On the other hand, some radiological features of OM can be confused with those of axial spondyloarthritis and lead to erroneous diagnoses. The current prevalence of OM is not known and is very likely that its incidence is much higher than previously thought. Moreover, OM explains part of the therapeutic failures that occur in patients diagnosed with other bone diseases. Therefore, it is essential that clinicians who treat adult skeletal diseases take into account the considerations provided in this practical review when focusing on the diagnosis and treatment of their patients with bone diseases.
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Affiliation(s)
- Luis Arboleya
- Rheumatology Division, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Ignacio Braña
- Rheumatology Division, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Estefanía Pardo
- Rheumatology Division, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Marta Loredo
- Rheumatology Division, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Rubén Queiro
- Rheumatology Division, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
- ISPA Translational Immunology Division, Biohealth Research Institute of the Principality of Asturias (ISPA), 33011 Oviedo, Spain
- School of Medicine, Oviedo University, 33011 Oviedo, Spain
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Kubota T, Namba N, Tanaka H, Muroya K, Imanishi Y, Takeuchi Y, Kanematsu M, Sun W, Seino Y, Ozono K. Self-Administration of Burosumab in Children and Adults with X-Linked Hypophosphataemia in Two Open-Label, Single-Arm Clinical Studies. Adv Ther 2023; 40:1530-1545. [PMID: 36719566 PMCID: PMC9887240 DOI: 10.1007/s12325-022-02412-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 12/15/2022] [Indexed: 02/01/2023]
Abstract
INTRODUCTION X-linked hypophosphataemia (XLH) is a rare, genetic renal phosphate-wasting disease, resulting from excess fibroblast growth factor 23 (FGF23) activity, which has a progressive and profound impact on patients throughout life. The monoclonal anti-FGF23 antibody, burosumab, is a subcutaneous injection indicated for the treatment of XLH in children and adults. Originally, burosumab was approved to be administered by a healthcare professional (HCP), but the option of self-administration would enable patient independence and easier access to treatment. Two open-label, single-arm clinical trials, conducted in Japan and Korea, have assessed the safety and efficacy of self-administration of burosumab in both children and adults with XLH. METHODS In KRN23-003 (n = 15 children aged 1-12 years) and KRN23-004 (n = 5 children aged 3-13 years, n = 4 adults aged 21-65 years), children initially received 0.8 mg/kg of burosumab every 2 weeks and adults initially received 1.0 mg/kg of burosumab every 4 weeks. Self-administration was permitted from Week 4, and patients or carers were provided with training to inject correctly. RESULTS In both trials, burosumab had an acceptable safety profile with mainly mild-to-moderate adverse events. Following self-administration, no patients reported serious treatment-emergent adverse events ≥ grade 3, injection-site reactions or hypersensitivity reactions related to burosumab. Serum phosphate and active vitamin D levels increased from baseline in children and adults. CONCLUSIONS These results indicated that the efficacy and safety of burosumab when administered either by a carer or patient are similar to that when administered by an HCP and show that self-administration is a viable option for patients with XLH. TRIAL REGISTRATION NUMBERS NCT03233126 and NCT04308096.
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Affiliation(s)
- Takuo Kubota
- Department of Paediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Noriyuki Namba
- Division of Paediatrics and Perinatology, Tottori University Faculty of Medicine, Tottori, Japan
| | - Hiroyuki Tanaka
- Department of Paediatrics, Okayama Saiseikai General Hospital, Okayama, Japan
| | - Koji Muroya
- Department of Endocrinology and Metabolism, Kanagawa Children's Medical Centre, Kanagawa, Japan
| | - Yasuo Imanishi
- Department of Metabolism, Endocrinology and Molecular Medicine, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan
| | - Yasuhiro Takeuchi
- Endocrine Centre, Toranomon Hospital, Tokyo, Japan
- Okinaka Memorial Institute for Medical Research, Tokyo, Japan
| | - Masanori Kanematsu
- Kyowa Kirin Co., Ltd., Oteomachi Financial City Grand Cube, 1-9-2 Otemachi, Chiyoda-ku, Tokyo, Japan.
| | - Wei Sun
- Kyowa Kirin, Inc., 212 Carnegie Centre, Princeton, NJ, 08540, USA
| | - Yoshiki Seino
- Department of Paediatrics, Osaka Hospital, Japan Community Healthcare Organisation, Osaka, Japan
| | - Keiichi Ozono
- Department of Paediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
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11
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Root AW, Levine MA. One half-century of advances in the evaluation and management of disorders of bone and mineral metabolism in children and adolescents. J Pediatr Endocrinol Metab 2023; 36:105-118. [PMID: 36636022 PMCID: PMC10406614 DOI: 10.1515/jpem-2022-0624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 01/14/2023]
Abstract
The past 50 years of research in pediatric bone and mineral metabolism have led to remarkable progress in the identification and characterization of disorders that affect the developing skeleton. Progress has been facilitated through advances in both technology and biology and this paper provides a brief description of some but not all of the key findings, including identification of the calcium sensing receptor and the polypeptides parathyroid hormone and parathyroid hormone-related protein as well as their shared receptor and signal generating pathways; the elucidation of vitamin D metabolism and actions; discovery of fibroblast growth factor 23 (FGF23), the sodium-phosphate co-transporters and the other components that regulate phosphate metabolism. Moreover, the past half-century of research has led to the delineation of the molecular bases for genetic forms of hypoparathyroidism, pseudohypoparathyroidism, and primary hyperparathyroidism as well as the determination of the genetic causes of osteogenesis imperfecta, osteopetrosis, hypophosphatasia, and other disorders of mineral/bone homeostasis. During the next decade we expect that many of these fundamental discoveries will lead to the development of innovative treatments that will improve the lives of children with these disorders.
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Affiliation(s)
- Allen W. Root
- Johns Hopkins All Children’s Hospital, St. Petersburg, FL, USA
| | - Michael A. Levine
- Corresponding author: Michael A. Levine, MD, The Center for Bone Health at the Children’s Hospital of Philadelphia, Philadelphia, PA, USA,
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12
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Impact of X-Linked Hypophosphatemia on Muscle Symptoms. Genes (Basel) 2022; 13:genes13122415. [PMID: 36553684 PMCID: PMC9778127 DOI: 10.3390/genes13122415] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/08/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is the most common hereditary form of rickets and deficiency of renal tubular phosphate transport in humans. XLH is caused by the inactivation of mutations within the phosphate-regulating endopeptidase homolog X-linked (PHEX) gene and follows an X-dominant transmission. It has an estimated frequency of 1 case per 20,000, and over 300 distinct pathogenic variations have been reported that result in an excess of fibroblast growth factor 23 (FGF23) in the serum. Increased levels of FGF23 lead to renal phosphate loss, decreased serum 1,25-dihydroxyvitamin D, and increased metabolism of 1,25-dihydoxyvitamin D, resulting in hypophosphatemia. Major clinical manifestations include rickets, bone deformities, and growth retardation that develop during childhood, and osteomalacia-related fractures or pseudo-fractures, degenerative osteoarthritis, enthesopathy, dental anomalies, and hearing loss during adulthood, which can affect quality of life. In addition, fatigue is also a common symptom in patients with XLH, who experience decreased motion, muscle weakness, and pain, contributing to altered quality of life. The clinical and biomedical characteristics of XLH are extensively defined in bone tissue since skeletal deformations and mineralization defects are the most evident effects of high FGF23 and low serum phosphate levels. However, despite the muscular symptoms that XLH causes, very few reports are available on the effects of FGF23 and phosphate in muscle tissue. Given the close relationship between bones and skeletal muscles, studying the effects of FGF23 and phosphate on muscle could provide additional opportunities to understand the interactions between these two important compartments of the body. By describing the current literature on XLH and skeletal muscle dysfunctions, the purpose of this review is to highlight future areas of research that could contribute to a better understanding of XLH muscular disability and its management.
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13
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Newey PJ, Hannan FM, Wilson A, Thakker RV. Genetics of monogenic disorders of calcium and bone metabolism. Clin Endocrinol (Oxf) 2022; 97:483-501. [PMID: 34935164 PMCID: PMC7614875 DOI: 10.1111/cen.14644] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 10/24/2021] [Accepted: 11/07/2021] [Indexed: 12/19/2022]
Abstract
Disorders of calcium homeostasis are the most frequent metabolic bone and mineral disease encountered by endocrinologists. These disorders usually manifest as primary hyperparathyroidism (PHPT) or hypoparathyroidism (HP), which have a monogenic aetiology in 5%-10% of cases, and may occur as an isolated endocrinopathy, or as part of a complex syndrome. The recognition and diagnosis of these disorders is important to facilitate the most appropriate management of the patient, with regard to both the calcium-related phenotype and any associated clinical features, and also to allow the identification of other family members who may be at risk of disease. Genetic testing forms an important tool in the investigation of PHPT and HP patients and is usually reserved for those deemed to be an increased risk of a monogenic disorder. However, identifying those suitable for testing requires a thorough clinical evaluation of the patient, as well as an understanding of the diversity of relevant phenotypes and their genetic basis. This review aims to provide an overview of the genetic basis of monogenic metabolic bone and mineral disorders, primarily focusing on those associated with abnormal calcium homeostasis, and aims to provide a practical guide to the implementation of genetic testing in the clinic.
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Affiliation(s)
- Paul J Newey
- Division of Molecular and Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Scotland, UK
| | - Fadil M Hannan
- Nuffield Department of Women's and Reproductive Health, University of Oxford, Oxford, UK
| | - Abbie Wilson
- Division of Molecular and Clinical Medicine, Ninewells Hospital & Medical School, University of Dundee, Scotland, UK
| | - Rajesh V Thakker
- Academic Endocrine Unit, Oxford Centre for Diabetes, Endocrinology & Metabolism (OCDEM), Churchill Hospital, University of Oxford, Oxford, UK
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14
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Castellano-Martinez A, Acuñas-Soto S, Roldan-Cano V, Rodriguez-Gonzalez M. Left Ventricular Hypertrophy in Patients with X-Linked Hypophosphataemia. J Clin Res Pediatr Endocrinol 2022; 14:344-349. [PMID: 33783172 PMCID: PMC9422913 DOI: 10.4274/jcrpe.galenos.2021.2020.0287] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare genetic disorder with X-linked dominant inheritance. Mutations in the PHEX gene increase fibroblast growth factor 23 (FGF23) concentrations, causing loss of phosphorus at the proximal tubule. Most pediatric patients debut in the first two years with short stature and bowed legs. Conventional treatment consists of oral supplements with phosphorus and calcitriol. Since 2018, burosumab has been approved as a novel therapeutic option for XLH, with promising results. The purpose of this study was to share our experience with two cases of XLH treated with burosumab. These patients presented with a broad phenotypical differences. One had the most severe radiological phenotype and developed left ventricular hypertrophy (LVH) and left ventricular dysfunction with preserved ejection fraction. Treatment with burosumab was well-tolerated and was followed by radiological stability and a striking improvement in both blood biochemistry and quality of life. The LVH was stable and left ventricular function normalized in the patient with cardiac involvement. In recent years many studies have been carried out to explain the role of FGF23 in cardiovascular damage, but the exact pathophysiological mechanisms are as yet unclear. The most intensively studied populations are patients with XLH or chronic kidney disease, as both are associated with high levels of FGF23. To date, cardiovascular involvement in XLH has been described in patients treated with conventional treatment, so it would be of interest to investigate if early use of burosumab at the time of diagnosis of XLH would prevent the occurrence of cardiovascular manifestations.
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Affiliation(s)
- Ana Castellano-Martinez
- Puerta del Mar University Hospital, Department of Pediatric Nephrology, Cadiz, Spain,* Address for Correspondence: Puerta del Mar University Hospital, Department of Pediatric Nephrology, Cadiz, Spain Phone: +34 956002700 E-mail:
| | - Silvia Acuñas-Soto
- Puerta del Mar University Hospital, Department of Pediatric Nephrology, Cadiz, Spain
| | - Virginia Roldan-Cano
- Puerta del Mar University Hospital, Department of Pediatric Nephrology, Cadiz, Spain
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15
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Ward LM, Glorieux FH, Whyte MP, Munns CF, Portale AA, Högler W, Simmons JH, Gottesman GS, Padidela R, Namba N, Cheong HI, Nilsson O, Mao M, Chen A, Skrinar A, Roberts MS, Imel EA. Effect of Burosumab Compared With Conventional Therapy on Younger vs Older Children With X-linked Hypophosphatemia. J Clin Endocrinol Metab 2022; 107:e3241-e3253. [PMID: 35533340 PMCID: PMC9282253 DOI: 10.1210/clinem/dgac296] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Indexed: 11/19/2022]
Abstract
CONTEXT Younger age at treatment onset with conventional therapy (phosphate salts and active vitamin D; Pi/D) is associated with improved growth and skeletal outcomes in children with X-linked hypophosphatemia (XLH). The effect of age on burosumab efficacy and safety in XLH is unknown. OBJECTIVE This work aimed to explore the efficacy and safety of burosumab vs Pi/D in younger (< 5 years) and older (5-12 years) children with XLH. METHODS This post hoc analysis of a 64-week, open-label, randomized controlled study took place at 16 academic centers. Sixty-one children aged 1 to 12 years with XLH (younger, n = 26; older, n = 35) participated. Children received burosumab starting at 0.8 mg/kg every 2 weeks (younger, n = 14; older, n = 15) or continued Pi/D individually titrated per recommended guidelines (younger, n = 12; older, n = 20). The main outcome measure included the least squares means difference (LSMD) in Radiographic Global Impression of Change (RGI-C) rickets total score from baseline to week 64. RESULTS The LSMD in outcomes through 64 weeks on burosumab vs conventional therapy by age group were as follows: RGI-C rickets total score (younger, +0.90; older, +1.07), total Rickets Severity Score (younger, -0.86; older, -1.44), RGI-C lower limb deformity score (younger, +1.02; older, +0.91), recumbent length or standing height Z-score (younger, +0.20; older, +0.09), and serum alkaline phosphatase (ALP) (younger, -31.15% of upper normal limit [ULN]; older, -52.11% of ULN). On burosumab, dental abscesses were not reported in younger children but were in 53% of older children. CONCLUSION Burosumab appears to improve outcomes both in younger and older children with XLH, including rickets, lower limb deformities, growth, and ALP, compared with Pi/D.
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Affiliation(s)
- Leanne M Ward
- Correspondence: Leanne M. Ward, MD, Pediatrics, University of Ottawa, Ottawa, Ontario, Canada, Rm 250H, 401 Smyth Rd, Ottawa, Ontario, K1H 8L1, Canada.
| | - Francis H Glorieux
- Shriners Hospitals for Children, Canada, McGill University, Montreal, Quebec H4A OA9, Canada
| | - Michael P Whyte
- Shriners Hospitals for Children St Louis, St Louis, Missouri 63110,USA
| | - Craig F Munns
- Child Health Research Centre, The University of Queensland, Brisbane, Queensland 4072, Australia
- Department of Endocrinology and Diabetes, Queensland Children’s Hospital, Brisbane, Queensland 4101, Australia
| | - Anthony A Portale
- Department of Pediatrics, University of California, San Francisco, San Francisco, California 94143, USA
| | - Wolfgang Högler
- Department of Pediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz 4040, Austria
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, B15 2TT, UK
| | - Jill H Simmons
- Department of Pediatrics, Division of Endocrinology and Diabetes, Vanderbilt University School of Medicine, Vanderbilt University, 680-8570 Nashville, Tennessee, 63110, USA
| | - Gary S Gottesman
- Shriners Hospitals for Children St Louis, St Louis, Missouri 63110, USA
| | - Raja Padidela
- Department of Paediatric Endocrinology, Royal Manchester Children’s Hospital, Manchester M13 9WL, UK
| | - Noriyuki Namba
- Department of Pediatrics, Osaka Hospital, Japan
- Community Healthcare Organization
- Osaka University Graduate School of Medicine, Osaka 553-0003, Japan
- Division of Pediatrics and Perinatology, Tottori University Faculty of Medicine, Yonago, Japan
| | - Hae Il Cheong
- Department of Pediatrics, Seoul National University Children’s Hospital, Seoul 14068, South Korea
| | - Ola Nilsson
- Division of Pediatric Endocrinology and Center for Molecular Medicine, Karolinska Institutet, Stockholm 17177, Sweden
- School of Medical Sciences, Department of Pediatrics, Örebro University and University Hospital, Örebro S-703 62, Sweden
| | - Meng Mao
- Ultragenyx Pharmaceutical Inc, Novato, California 94949, USA
| | - Angel Chen
- Ultragenyx Pharmaceutical Inc, Novato, California 94949, USA
| | - Alison Skrinar
- Ultragenyx Pharmaceutical Inc, Novato, California 94949, USA
| | | | - Erik A Imel
- Department of Medicine and Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indianapolis 46202, USA
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16
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X-Linked Hypophosphatemia Transition and Team Management. ENDOCRINES 2022. [DOI: 10.3390/endocrines3030032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is the most common form of inherited disorders that are characterized by renal phosphate wasting, but it is a rare chronic disease. XLH presents in multisystemic organs, not only in childhood, but also in adulthood. Multidisciplinary team management is necessary for the care of patients with XLH. Although XLH has often been perceived as a childhood disease, recent studies have demonstrated that it is a long-term and progressive disease throughout adulthood. In the past 20 years, the importance of the transition from pediatric care to adult care for patient outcomes in adulthood in many pediatric onset diseases has been increasingly recognized. This review describes transitional care and team management for patients with XLH.
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Ornitz DM, Itoh N. New developments in the biology of fibroblast growth factors. WIREs Mech Dis 2022; 14:e1549. [PMID: 35142107 PMCID: PMC10115509 DOI: 10.1002/wsbm.1549] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/08/2021] [Accepted: 11/09/2021] [Indexed: 01/28/2023]
Abstract
The fibroblast growth factor (FGF) family is composed of 18 secreted signaling proteins consisting of canonical FGFs and endocrine FGFs that activate four receptor tyrosine kinases (FGFRs 1-4) and four intracellular proteins (intracellular FGFs or iFGFs) that primarily function to regulate the activity of voltage-gated sodium channels and other molecules. The canonical FGFs, endocrine FGFs, and iFGFs have been reviewed extensively by us and others. In this review, we briefly summarize past reviews and then focus on new developments in the FGF field since our last review in 2015. Some of the highlights in the past 6 years include the use of optogenetic tools, viral vectors, and inducible transgenes to experimentally modulate FGF signaling, the clinical use of small molecule FGFR inhibitors, an expanded understanding of endocrine FGF signaling, functions for FGF signaling in stem cell pluripotency and differentiation, roles for FGF signaling in tissue homeostasis and regeneration, a continuing elaboration of mechanisms of FGF signaling in development, and an expanding appreciation of roles for FGF signaling in neuropsychiatric diseases. This article is categorized under: Cardiovascular Diseases > Molecular and Cellular Physiology Neurological Diseases > Molecular and Cellular Physiology Congenital Diseases > Stem Cells and Development Cancer > Stem Cells and Development.
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Affiliation(s)
- David M Ornitz
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Nobuyuki Itoh
- Kyoto University Graduate School of Pharmaceutical Sciences, Sakyo, Kyoto, Japan
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Hamilton AA, Faitos S, Jones G, Kinsley A, Gupta RN, Lewiecki EM. Whole Body, Whole Life, Whole Family: Patients’ Perspectives on X-Linked Hypophosphatemia. J Endocr Soc 2022; 6:bvac086. [PMID: 35860754 PMCID: PMC9290905 DOI: 10.1210/jendso/bvac086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Indexed: 11/19/2022] Open
Abstract
Abstract
The rare genetic disorder X-linked hypophosphatemia (XLH) is often exclusively considered to impact children, and as such, adult patients with XLH may receive inadequate care because their symptoms are not associated with XLH. However, studies have shown that XLH has long-term adverse health consequences that continue throughout adulthood requiring comprehensive lifelong care. Indeed, XLH impacts patients’ whole body, whole life, and whole family. XLH does not just affect the bones; symptoms are chronic and progressive, worsening throughout adulthood, and the burden of XLH overflows into the lives of patients’ family, friends, peers, and colleagues. To ensure early recognition, comprehensive care, and adequate management of XLH, there are key steps that clinicians can incorporate into their daily practice. These include education, a multidisciplinary approach, open communication, and support. Clinician education on rare disorders such as XLH is critical, and healthcare professionals (HCPs) should ensure that patients and their caregivers have access to XLH-related information. As a whole-body disorder, XLH requires a coordinated approach to treatment across specialties. Frequent open communication among members of the healthcare team is needed to increase HCPs’ knowledge about XLH, and open communication must extend to the patient as well to ensure the patient’s concerns and needs are addressed and treatment tailored to their specific individual needs. Multiple networks of support, including social and psychological support, should be offered to patients and their families. A basic understanding that XLH affects patients’ whole bodies, whole lives, and whole families is the first step toward accomplishing improved patient care.
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Ferreira CR, Ansh AJ, Nester C, O’Brien C, Stabach PR, Murtada SI, Lester ER, Khursigara G, Molloy L, Carpenter TO, Braddock DT. Musculoskeletal Comorbidities and Quality of Life in ENPP1-Deficient Adults and the Response of Enthesopathy to Enzyme Replacement Therapy in Murine Models. J Bone Miner Res 2022; 37:494-504. [PMID: 34882836 PMCID: PMC9667476 DOI: 10.1002/jbmr.4487] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/04/2021] [Accepted: 12/05/2021] [Indexed: 12/20/2022]
Abstract
Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) deficiency leads to cardiovascular calcification in infancy, fibroblast growth factor 23 (FGF23)-mediated hypophosphatemic rickets in childhood, and osteomalacia in adulthood. Excessive enthesis mineralization and cervical spine fusion have been previously reported in patients with biallelic ENPP1 deficiency, but their effect on quality of life is unknown. We describe additional musculoskeletal complications in patients with ENPP1 deficiency, namely osteoarthritis and interosseous membrane ossification, and for the first time evaluate health-related quality of life (HRQoL) in patients with this disease, both subjectively via narrative report, and objectively via the Brief Pain Inventory-Short Form, and a Patient Reported Outcome Measurement Information System Physical Function (PROMIS PF) short form. Residual pain, similar in magnitude to that identified in adult patients with X-linked hypophosphatemia, was experienced by the majority of patients despite use of analgesic medications. Impairment in physical function varied from mild to severe. To assess murine ENPP1 deficiency for the presence of enthesopathy, and for the potential response to enzyme replacement therapy, we maintained Enpp1asj/asj mice on regular chow for 23 weeks and treated cohorts with either vehicle or a long-acting form of recombinant ENPP1. Enpp1asj/asj mice treated with vehicle exhibited robust calcification throughout their Achilles tendons, whereas two-thirds of those treated with ENPP1 enzyme replacement exhibited complete or partial suppression of the Achilles tendon calcification. Our combined results document that musculoskeletal complications are a significant source of morbidity in biallelic ENPP1 deficiency, a phenotype which is closely recapitulated in Enpp1asj/asj mice. Finally, we show that a long-acting form of recombinant ENPP1 prevents the development of enthesis calcification at the relatively modest dose of 0.3 mg/kg per week, suggesting that suppression of enthesopathy may be attainable upon dose escalation. © 2021 American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.
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Affiliation(s)
- Carlos R. Ferreira
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Anenya Jai Ansh
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Paul R. Stabach
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | - Sae-Il Murtada
- Department of Biomedical Engineering, Yale University, New Haven, CT, USA
| | - Ethan R. Lester
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | | | | | - Thomas O. Carpenter
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, New Haven, CT, USA
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Dahir K, Dhaliwal R, Simmons J, Imel EA, Gottesman GS, Mahan JD, Prakasam G, Hoch AI, Ramesan P, Díaz-González de Ferris M. Health Care Transition From Pediatric- to Adult-Focused Care in X-linked Hypophosphatemia: Expert Consensus. J Clin Endocrinol Metab 2022; 107:599-613. [PMID: 34741521 PMCID: PMC8852209 DOI: 10.1210/clinem/dgab796] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Indexed: 12/02/2022]
Abstract
CONTEXT X-linked hypophosphatemia (XLH) is an inherited skeletal disorder that can lead to lifelong deleterious musculoskeletal and functional consequences. Although often perceived as a childhood condition, children and adults both experience the negative effects of XLH. Adolescents and young adults (AYAs) benefit from effective health care transition (HCT) preparation to support the transfer from pediatric- to adult-focused care. Whereas transition timelines, milestones, and educational tools exist for some chronic conditions, they do not meet the unique needs of patients with XLH. EVIDENCE ACQUISITION To produce the first expert recommendations on HCT preparation for AYAs with XLH developed by clinical care investigators and transition experts, a formal literature search was conducted and discussed in an advisory board meeting in July 2020. A modified Delphi method was used to refine expert opinion and facilitate a consensus position. EVIDENCE SYNTHESIS We identified the need for psychosocial and access-related resources for disease education, genetic counseling, family planning, and AYA emancipation from caregiver-directed care. Additionally, we recognized that it is necessary to facilitate communication with patients through channels familiar and accessible to AYAs and teach patients to advocate for their health care/access to specialists. CONCLUSION Clear HCT preparation guidelines and treatment-related goals are defined. Individualized timelines and practical strategies for HCT preparation are proposed to optimize health outcomes resulting from continuous clinical care throughout the patient lifecycle. We provide an expert consensus statement describing a tailored HCT preparation program specifically for AYAs with XLH to aid in the effective transfer from pediatric- to adult-focused health care.
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Affiliation(s)
- Kathryn Dahir
- Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
- Correspondence: Kathryn Dahir, MD, Vanderbilt University Medical Center, South Tower, 1215 21st Ave S, Ste 8210, Nashville, TN 37232, USA.
| | - Ruban Dhaliwal
- SUNY Upstate Medical University, Syracuse, New York 13210, USA
| | - Jill Simmons
- Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
| | - Erik A Imel
- Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | - Gary S Gottesman
- Shriners Hospitals for Children–St Louis, St Louis, Missouri 63110,USA
| | - John D Mahan
- Nationwide Children’s Hospital, Columbus, Ohio 43205, USA
| | | | - Allison I Hoch
- Ultragenyx Pharmaceutical Inc, Novato, California 94949, USA
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21
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DeCorte J, Randazzo E, Black M, Hendrickson C, Dahir K. Rare Diseases That Impersonate One Another:
X‐Linked
Hypophosphatemia and
Tumor‐Induced
Osteomalacia, a Retrospective Analysis of Discriminating Features. JBMR Plus 2022; 6:e10580. [PMID: 35229062 PMCID: PMC8861982 DOI: 10.1002/jbm4.10580] [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: 09/19/2021] [Revised: 11/01/2021] [Accepted: 11/07/2021] [Indexed: 11/11/2022] Open
Abstract
Tumor‐induced osteomalacia (TIO) is a rare paraneoplastic disease characterized by frequent fractures, bone pain, muscle weakness, and affected gait. The rarity of TIO and similar presentation to other phosphate‐wasting disorders contribute to a high misdiagnosis rate and long time to correct diagnosis. TIO is curable by tumor resection, so accurate diagnosis has significant impact on patients' emotional and economic burden. Current diagnostics for TIO rely on decades‐old literature with poor phenotypic validation. Here, we identify salient clinical differences between rigorously validated cohorts of patients with TIO (n = 9) and X‐linked hypophosphatemia (XLH; n = 43), a frequent misdiagnosis for patients with TIO. The TIO cohort had significantly elevated FGF23 (365 versus 95 RU/mL, p < 0.001) and alkaline phosphatase (282.8 versus 118.5 IU/L, p < 0.01) but significantly reduced phosphorus (1.4 versus 2.2 mg/dL, p < 0.05) and 1,25(OH)2 D (16.6 versus 59.8 pg/mL, p < 0.01). By contrast, total vitamin D was similar between the two groups. Dual‐energy X‐ray absorptiometry (DXA) scans reveal lower Z‐scores in the hip (−1.6 versus 0.050, p < 0.01) and spine (0.80 versus 2.35, p < 0.05). TIO patients were more likely to have prior clinical diagnosis of osteoporosis (67% versus 0%), use assistive devices in daily living (100% versus 14%), and have received a knee arthroplasty (33% versus 7%). TIO patients lost an average of 1.5 cm over their disease course and had sustained an average of 8 fractures each, whereas fractures were rare in XLH. The XLH cohort had higher incidence of osteotomy (19% versus 0%), spinal stenosis (12% versus 0%), secondary dental abnormalities (95% versus 44%, p < 0.001), and depression and anxiety (46.5% versus 11%). These results deepen our understanding of the subtle differences present between diseases of phosphate wasting. They suggest several biochemical, clinical, and historical features that effectively distinguish TIO from XLH. © 2022 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)
- Joseph DeCorte
- Vanderbilt Medical Scientist Training Program Vanderbilt University Medical Center, Vanderbilt University School of Medicine Nashville TN USA
| | - Ericka Randazzo
- Vanderbilt Medical Scientist Training Program Vanderbilt University Medical Center, Vanderbilt University School of Medicine Nashville TN USA
| | - Margo Black
- Program for Metabolic Bone Disorders at Vanderbilt, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine Vanderbilt University Medical Center Nashville TN USA
| | - Chase Hendrickson
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine Vanderbilt University Medical Center Nashville TN USA
| | - Kathryn Dahir
- Program for Metabolic Bone Disorders at Vanderbilt, Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine Vanderbilt University Medical Center Nashville TN USA
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22
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Thrailkill KM, Kalaitzoglou E, Fowlkes JL. Emerging therapies for the treatment of rare pediatric bone disorders. Front Pediatr 2022; 10:1012816. [PMID: 36304528 PMCID: PMC9592743 DOI: 10.3389/fped.2022.1012816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/09/2022] [Indexed: 11/24/2022] Open
Abstract
In recent years, new therapies for the treatment of rare pediatric bone disorders have emerged, guided by an increasing understanding of the genetic and molecular etiology of these diseases. Herein, we review three such disorders, impacted by debilitating deficits in bone mineralization or cartilage ossification, as well as the novel disease-modifying drugs that are now available to treat these conditions. Specifically, we discuss asfotase alfa, burosumab-twza, and vosoritide, for the treatment of hypophosphatasia, X-linked hypophosphatemia and achondroplasia, respectively. For each skeletal disorder, an overview of the clinical phenotype and natural history of disease is provided, along with a discussion of the clinical pharmacology, mechanism of action and FDA indication for the relevant medication. In each case, a brief review of clinical trial data supporting drug development for each medication is provided. Additionally, guidance as to drug dosing and long-term monitoring of adverse events and pediatric efficacy is presented, to aid the clinician seeking to utilize these novel therapies in their practice, or to become familiar with the healthcare expectations for children receiving these medications through specialized multidisciplinary clinics. The availability of these targeted therapies now significantly augments treatment options for conditions in which past therapy has relied upon less specific, symptomatic medical and orthopedic care.
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Affiliation(s)
- Kathryn M Thrailkill
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Evangelia Kalaitzoglou
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - John L Fowlkes
- Department of Pediatrics, University of Kentucky Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, United States
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23
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Mughal MZ, Baroncelli GI, de Lucas-Collantes C, Linglart A, Magnolato A, Raimann A, Santos F, Schnabel D, Shaw N, Nilsson O. Burosumab for X-linked hypophosphatemia in children and adolescents: Opinion based on early experience in seven European countries. Front Endocrinol (Lausanne) 2022; 13:1034580. [PMID: 36798486 PMCID: PMC9928183 DOI: 10.3389/fendo.2022.1034580] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 11/11/2022] [Indexed: 02/03/2023] Open
Abstract
Given the relatively recent introduction of burosumab in the management of X-linked hypophosphatemia (XLH), there is limited real-world data to guide its use in clinical practice. As a group of European physicians experienced with burosumab treatment in clinical practice, we convened with the objective of sharing these practice-based insights on the use of burosumab in children and adolescents with XLH. We attended two virtual meetings, then discussed key questions via Within3, a virtual online platform. Points of discussion related to patient selection criteria, burosumab starting dose, dose titration and treatment monitoring. Our discussions revealed that criteria for selecting children with XLH varied across Europe from all children above 1 year to only children with overt rickets despite conventional treatment being eligible. We initiated burosumab dosing according to guidance in the Summary of Product Characteristics, an international consensus statement from 2019 and local country guidelines. Dose titration was primarily guided by serum phosphate levels, with some centers also using the ratio of tubular maximum reabsorption of phosphate to glomerular filtration rate (TmP/GFR). We monitored response to burosumab treatment clinically (growth, deformities, bone pain and physical functioning), radiologically (rickets and deformities) and biochemically (serum phosphate, alkaline phosphatase, 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, urine calcium-creatinine ratio and TmP/GFR). Key suggestions made by our group were initiation of burosumab treatment in children as early as possible, from the age of 1 year, particularly in those with profound rickets, and a need for clinical studies on continuation of burosumab throughout adolescence and into adulthood.
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Affiliation(s)
- M. Zulf Mughal
- Department of Paediatric Endocrinology and Metabolic Bone Diseases, Royal Manchester Children’s Hospital, Manchester, United Kingdom
- The Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom
- *Correspondence: M. Zulf Mughal,
| | - Giampiero I. Baroncelli
- Division of Pediatrics, Endocrine Unit, ERN-BOND Representative, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Pisa, Italy
| | - Carmen de Lucas-Collantes
- Servicio Nefrología, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
| | - Agnès Linglart
- AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR, Bicêtre Paris Saclay Hospital, Paris, France
- Platform of Expertise for Rare Disorders, INSERM, Physiologie et Physiopathologie Endocriniennes, Paris Saclay University, Paris, France
| | - Andrea Magnolato
- Department of Pediatrics, Institute for Maternal and Child Health – IRCCS “Burlo Garofolo”, Trieste, Italy
| | - Adalbert Raimann
- Department of Pediatrics and Adolescent Medicine, Division of Pediatric Pulmonology, Allergology and Endocrinology, Medical University of Vienna, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | - Fernando Santos
- Hospital Universitario Central de Asturias (HUCA), University of Oviedo, Oviedo, Spain
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charitè, University Medicine, Berlin, Germany
| | - Nick Shaw
- Department of Endocrinology and Diabetes, Birmingham Women’s and Children’s NHS Foundation Trust, Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom
| | - Ola Nilsson
- Division of Pediatric Endocrinology, Department of Women’s and Children’s Health , Karolinska Institutet and University Hospital, Stockholm, Sweden
- School of Medical Sciences, Department of Pediatrics, Örebro University and University Hospital, Örebro, Sweden
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24
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Delsmann MM, Seist R, Stürznickel J, Schmidt FN, Mansour A, Kobelski MM, Broocks G, Peichl J, Oheim R, Praetorius M, Schinke T, Amling M, Demay MB, Stankovic KM, Rolvien T. Conductive Hearing Loss in the Hyp Mouse Model of X-Linked Hypophosphatemia Is Accompanied by Hypomineralization of the Auditory Ossicles. J Bone Miner Res 2021; 36:2317-2328. [PMID: 34523743 PMCID: PMC8688200 DOI: 10.1002/jbmr.4443] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 08/27/2021] [Accepted: 09/13/2021] [Indexed: 01/10/2023]
Abstract
X-linked hypophosphatemia (XLH) is a hereditary musculoskeletal disorder caused by loss-of-function mutations in the PHEX gene. In XLH, increased circulating fibroblast growth factor 23 (FGF23) levels cause renal phosphate wasting and low concentrations of 1,25-dihydroxyvitamin D, leading to an early clinical manifestation of rickets. Importantly, hearing loss is commonly observed in XLH patients. We present here data from two XLH patients with marked conductive hearing loss. To decipher the underlying pathophysiology of hearing loss in XLH, we utilized the Hyp mouse model of XLH and measured auditory brain stem responses (ABRs) and distortion product otoacoustic emissions (DPOAEs) to functionally assess hearing. As evidenced by the increased ABR/DPOAE threshold shifts in the mid-frequency range, these measurements indicated a predominantly conductive hearing loss in Hyp mice compared to wild-type (WT) mice. Therefore, we carried out an in-depth histomorphometric and scanning electron microscopic analysis of the auditory ossicles. Quantitative backscattered electron imaging (qBEI) indicated a severe hypomineralization of the ossicles in Hyp mice, evidenced by lower calcium content (CaMean) and higher void volume (ie, porosity) compared to WT mice. Histologically, voids correlated with unmineralized bone (ie, osteoid), and the osteoid volume per bone volume (OV/BV) was markedly higher in Hyp mice than WT mice. The density of osteocyte lacunae was lower in Hyp mice than in WT mice, whereas osteocyte lacunae were enlarged. Taken together, our findings highlight the importance of ossicular mineralization for hearing conduction and point toward the potential benefit of improving mineralization to prevent hearing loss in XLH. © 2021 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)
- Maximilian M Delsmann
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Richard Seist
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Julian Stürznickel
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Felix N Schmidt
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Amer Mansour
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA
| | - Margaret M Kobelski
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Gabriel Broocks
- Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jonathan Peichl
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Ralf Oheim
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Mark Praetorius
- Department of Otorhinolaryngology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Thorsten Schinke
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Michael Amling
- Department of Osteology and Biomechanics, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Marie B Demay
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Konstantina M Stankovic
- Department of Otolaryngology-Head and Neck Surgery, Massachusetts Eye and Ear and Harvard Medical School, Boston, MA, USA.,Department of Otolaryngology-Head and Neck Surgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Tim Rolvien
- Department of Trauma and Orthopaedic Surgery, Division of Orthopaedics, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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25
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Sarafrazi S, Daugherty SC, Miller N, Boada P, Carpenter TO, Chunn L, Dill K, Econs MJ, Eisenbeis S, Imel EA, Johnson B, Kiel MJ, Krolczyk S, Ramesan P, Truty R, Sabbagh Y. Novel PHEX gene locus-specific database: Comprehensive characterization of vast number of variants associated with X-linked hypophosphatemia (XLH). Hum Mutat 2021; 43:143-157. [PMID: 34806794 PMCID: PMC9299612 DOI: 10.1002/humu.24296] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/17/2021] [Accepted: 11/18/2021] [Indexed: 02/01/2023]
Abstract
X‐linked hypophosphatemia (XLH), the most common form of hereditary hypophosphatemia, is caused by disrupting variants in the PHEX gene, located on the X chromosome. XLH is inherited in an X‐linked pattern with complete penetrance observed for both males and females. Patients experience lifelong symptoms resulting from chronic hypophosphatemia, including impaired bone mineralization, skeletal deformities, growth retardation, and diminished quality of life. This chronic condition requires life‐long management with disease‐specific therapies, which can improve patient outcomes especially when initiated early in life. To centralize and disseminate PHEX variant information, we have established a new PHEX gene locus‐specific database, PHEX LSDB. As of April 30, 2021, 870 unique PHEX variants, compiled from an older database of PHEX variants, a comprehensive literature search, a sponsored genetic testing program, and XLH clinical trials, are represented in the PHEX LSDB. This resource is publicly available on an interactive, searchable website (https://www.rarediseasegenes.com/), which includes a table of variants and associated data, graphical/tabular outputs of genotype‐phenotype analyses, and an online submission form for reporting new PHEX variants. The database will be updated regularly with new variants submitted on the website, identified in the published literature, or shared from genetic testing programs.
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Affiliation(s)
- Soodabeh Sarafrazi
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Sean C Daugherty
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Nicole Miller
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Patrick Boada
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Thomas O Carpenter
- Department of Pediatrics (Endocrinology), Yale University School of Medicine, New Haven, Connecticut, USA
| | - Lauren Chunn
- Data Science, Genomenon Inc., Ann Arbor, Michigan, USA
| | - Kariena Dill
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Michael J Econs
- Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Scott Eisenbeis
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Erik A Imel
- Division of Endocrinology and Metabolism, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Britt Johnson
- Medical Affairs, Invitae Corporation, San Francisco, California, USA
| | - Mark J Kiel
- Data Science, Genomenon Inc., Ann Arbor, Michigan, USA
| | - Stan Krolczyk
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Prameela Ramesan
- Medical Affairs, Ultragenyx Pharmaceutical, Inc., Novato, California, USA
| | - Rebecca Truty
- External Relations, Invitae Corporation, San Francisco, California, USA
| | - Yves Sabbagh
- Research and Development, Inozyme Pharma, Boston, Massachusetts, USA
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26
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Baroncelli GI, Mora S. X-Linked Hypophosphatemic Rickets: Multisystemic Disorder in Children Requiring Multidisciplinary Management. Front Endocrinol (Lausanne) 2021; 12:688309. [PMID: 34421819 PMCID: PMC8378329 DOI: 10.3389/fendo.2021.688309] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 06/14/2021] [Indexed: 12/14/2022] Open
Abstract
X-linked hypophosphatemic rickets (XLH) is the commonest inherited form of rickets. It is caused by an impaired regulation of fibroblast growth factor 23 (FGF23) due to a PHEX gene mutation, which leads to reduced tubular reabsorption of phosphate and renal 1α-hydroxylase activity and increased renal 24-hydroxylase activity. Hypophosphatemia associated with renal phosphate wasting, normal serum levels of calcium, parathyroid hormone, and 25-hydroxyvitamin D represents the main biochemical sign in affected patients. Patients with XLH show rickets and osteomalacia, severe deformities of the lower limbs, bone and muscular pain, stunted growth, and reduced quality of life. However, XLH is a multisystemic disorder requiring multidisciplinary approaches in specialized subdisciplines. Severe complications may occur in patients with XLH including craniosynostosis, hearing loss, progressive bone deformities, dental and periodontal recurrent lesions, and psychosocial distress. Moreover, long-term conventional treatment with active vitamin D metabolites and oral inorganic phosphate salts may cause endocrinological complications such as secondary or tertiary hyperparathyroidism, and adverse events in kidney as hypercalciuria, nephrocalcinosis, and nephrolithiasis. However, conventional treatment does not improve phosphate metabolism and it shows poor and slow effects in improving rickets lesions and linear growth. Recently, some trials of treatment with recombinant human IgG1 monoclonal antibody that targets FGF23 (burosumab) showed significant improvement of serum phosphate concentration and renal tubular reabsorption of phosphate that were associated with a rapid healing of radiologic signs of rickets, reduced muscular and osteoarticular pain, and improved physical function, being more effective for the treatment of patients with XLH in comparison with conventional therapy. Therefore, a global management of patients with XLH is strongly recommended and patients should be seen regularly by a multidisciplinary team of experts.
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Affiliation(s)
- Giampiero Igli Baroncelli
- Pediatric and Adolescent Endocrinology, Department of Obstetrics, Gynecology and Pediatrics, University Hospital, Pisa, Italy
- *Correspondence: Giampiero Igli Baroncelli, ; Stefano Mora,
| | - Stefano Mora
- Laboratory of Pediatric Endocrinology and Bone Densitometry Service, IRCCS San Raffaele Scientific Institute, Milan, Italy
- *Correspondence: Giampiero Igli Baroncelli, ; Stefano Mora,
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