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Chaturvedi D, Mehasi TE, Benbrahim A, ElDeeb L, Deeb A. Lessons learned from the real-world diagnosis and management of hereditary hypophosphatemic rickets. Bone Rep 2024; 21:101753. [PMID: 39011543 PMCID: PMC11247149 DOI: 10.1016/j.bonr.2024.101753] [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: 02/27/2024] [Accepted: 03/20/2024] [Indexed: 07/17/2024] Open
Abstract
Hypophosphatemic rickets, which is often hereditary, is still under- or misdiagnosed in both children and adults, denying these individuals access to optimal management and genetic counseling. There have been recent calls to compile real-world data and share best practice on these rare conditions to guide clinical decision-making. Here we present eight clinical vignettes of patients with hypophosphatemic rickets encountered in our tertiary pediatric endocrinology practice. We describe the clinical features, genetics, and management of four cases of X-linked hypophosphatemia (PHEX mutations), one each of autosomal recessive hypophosphatemic rickets (DMP1 mutation) and autosomal recessive vitamin D-dependent rickets type 1A (CYP27B1 mutation), and two cases of distal renal tubular acidosis with FOXI1 mutation-associated hypophosphatemic rickets. Our cases prompt consideration of the (i) frequent misdiagnosis of hypophosphatemic rickets in clinical practice and the importance of comprehensive genetic testing; (ii) variable expressivity of the causative mutations; and (iii) a lack of responsiveness and/or compliance to conventional therapy and the value of burosumab in modern management, provided access is equitable. These cases highlight common real-world themes and challenges to managing patients presenting with these diverse conditions, especially the burden of disease hidden by misdiagnosis. In sharing these cases, we hope to raise awareness of these conditions, promote best practice in genetic diagnosis and management, and further advocate for reimbursement equity for the best available therapies.
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Affiliation(s)
- Deepti Chaturvedi
- Paediatric Endocrine Division, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
| | - Taif EmadEldin Mehasi
- Paediatric Endocrine Division, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
| | - Assia Benbrahim
- Paediatric Endocrine Division, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
| | - Lubna ElDeeb
- Clinical Trial Unit, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
| | - Asma Deeb
- Paediatric Endocrine Division, Sheikh Shakhbout Medical City, Abu Dhabi, United Arab Emirates
- Faculty of Health and Science, Khalifa University, Abu Dhabi, UAE
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2
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Bosman A, Appelman-Dijkstra NM, Boot AM, de Borst MH, van de Ven AC, de Jongh RT, Bökenkamp A, van den Bergh JP, van der Eerden BCJ, Zillikens MC. Disease Manifestations and Complications in Dutch X-Linked Hypophosphatemia Patients. Calcif Tissue Int 2024; 114:255-266. [PMID: 38226986 PMCID: PMC10901935 DOI: 10.1007/s00223-023-01172-2] [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: 09/12/2023] [Accepted: 11/27/2023] [Indexed: 01/17/2024]
Abstract
X-linked hypophosphatemia (XLH) is the most common monogenetic cause of chronic hypophosphatemia, characterized by rickets and osteomalacia. Disease manifestations and treatment of XLH patients in the Netherlands are currently unknown. Characteristics of XLH patients participating in the Dutch observational registry for genetic hypophosphatemia and acquired renal phosphate wasting were analyzed. Eighty XLH patients, including 29 children, were included. Genetic testing, performed in 78.8% of patients, showed a PHEX mutation in 96.8%. Median (range) Z-score for height was - 2.5 (- 5.5; 1.0) in adults and - 1.4 (- 3.7; 1.0) in children. Many patients were overweight or obese: 64.3% of adults and 37.0% of children. All children received XLH-related medication e.g., active vitamin D, phosphate supplementation or burosumab, while 8 adults used no medication. Lower age at start of XLH-related treatment was associated with higher height at inclusion. Hearing loss was reported in 6.9% of children and 31.4% of adults. Knee deformities were observed in 75.0% of all patients and osteoarthritis in 51.0% of adult patients. Nephrocalcinosis was observed in 62.1% of children and 33.3% of adults. Earlier start of XLH-related treatment was associated with higher risk of nephrocalcinosis and detection at younger age. Hyperparathyroidism longer than six months was reported in 37.9% of children and 35.3% of adults. This nationwide study confirms the high prevalence of adiposity, hearing loss, bone deformities, osteoarthritis, nephrocalcinosis and hyperparathyroidism in Dutch XLH patients. Early start of XLH-related treatment appears to be beneficial for longitudinal growth but may increase development of nephrocalcinosis.
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Affiliation(s)
- A Bosman
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000, CA, Rotterdam, The Netherlands
| | - N M Appelman-Dijkstra
- Department of Internal Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - A M Boot
- Department of Pediatrics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - M H de Borst
- Department of Internal Medicine, University Medical Center Groningen, Groningen, The Netherlands
| | - A C van de Ven
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - R T de Jongh
- Department of Internal Medicine, Amsterdam University Medical Center, Vrije Universiteit, Amsterdam, The Netherlands
| | - A Bökenkamp
- Department of Pediatric Nephrology, Amsterdam University Medical Center, Emma Children's Hospital, Amsterdam, The Netherlands
| | - J P van den Bergh
- Department of Internal Medicine, VieCuri Medical Center, Venlo, The Netherlands
| | - B C J van der Eerden
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000, CA, Rotterdam, The Netherlands
| | - M C Zillikens
- Department of Internal Medicine, Erasmus MC, University Medical Center Rotterdam, PO Box 2040, 3000, CA, Rotterdam, The Netherlands.
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Vaisbich MH, de Cillo ACP, Silva BCC, DÁlva CB, de Carvalho ÉH, de Almeida JMCM, Marques LLM, Ribeiro M, da Silva MBM, de Medeiros PFV, Mendes PH. Real-world data of Brazilian adults with X-linked hypophosphatemia (XLH) treated with burosumab and comparison with other worldwide cohorts. Mol Genet Genomic Med 2024; 12:e2387. [PMID: 38337160 PMCID: PMC10858313 DOI: 10.1002/mgg3.2387] [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: 07/31/2023] [Revised: 12/23/2023] [Accepted: 01/17/2024] [Indexed: 02/12/2024] Open
Abstract
BACKGROUND Disease-related variants in PHEX cause XLH by an increase of fibroblast growth factor 23 (FGF23) circulating levels, resulting in hypophosphatemia and 1,25(OH)2 vitamin D deficiency. XLH manifests in early life with rickets and persists in adulthood with osseous and extraosseous manifestations. Conventional therapy (oral phosphate and calcitriol) improves some symptoms, but evidence show that it is not completely effective, and it can lead to nephrocalcinosis (NC) and hyperparathyroidism (HPT). Burosumab (anti-FGF23 antibody) has shown to be effective and safety in the clinical trials. METHODS The current real-world collaborative study evaluated genetic, clinical and laboratory data of XLH Brazilian adult patients treated with burosumab. RESULTS Nineteen unrelated patients were studied. Patients reported pain, limb deformities and claudication, before burosumab initiation. 78% of them were previously treated with conventional therapy. The severity of the disease was moderate to severe (15 patients with score >5). At the baseline, 3 patients presented NC (16.7%) and 12 HPT (63%). After 16 ± 8.4 months under burosumab, we observed a significant: increase in stature (p = 0.02), in serum phosphate from 1.90 ± 0.43 to 2.67 ± 0.52 mg/dL (p = 0.02); in TmP/GFR from 1.30 ± 0.46 to 2.27 ± 0.64 mg/dL (p = 0.0001), in 1,25 (OH)2 D from 50.5 ± 23.3 to 71.1 ± 19.1 pg/mL (p = 0.03), and a decrease in iPTH from 86.8 ± 37.4 pg/mL to 66.5 ± 31.1 (p = 0.002). Nineteen variants were found (10 novel). HPT tended to develop in patients with truncated PHEX variants (p = 0.06). CONCLUSIONS This study confirms the efficacy and safety of burosumab on XLH adult patients observed in clinical trials. Additionally, we observed a decrease in iPTH levels in patients with moderate to severe HPT at the baseline.
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Affiliation(s)
| | | | - Bárbara Campolina C. Silva
- Hospital Felício Rocho, Osteometabolism Unit of Santa Casa de Belo HorizonteProfessor of Medicine at University Center of Belo Horizonte – UNIBHBelo HorizonteBrazil
| | | | - Érico Higino de Carvalho
- Instituto de Medicina Integrada Professor Fernado Figueira, recifeFederal University of PernambucoRecifeBrazil
| | | | | | - Marcia Ribeiro
- Genetic Unit of Federal University of Rio de JaneiroRio de JaneiroBrazil
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Park E, Kang HG. X-linked hypophosphatemic rickets: from diagnosis to management. Clin Exp Pediatr 2024; 67:17-25. [PMID: 37321578 PMCID: PMC10764665 DOI: 10.3345/cep.2022.01459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 02/02/2023] [Accepted: 03/28/2023] [Indexed: 06/17/2023] Open
Abstract
X-linked hypophosphatemia (XLH), the most common cause of hypophosphatemic rickets, affects one in every 20,000 people. Although conventional therapy for XLH was introduced approximately 4 decades ago, the temporary replacement of oral phosphate salts and activated vitamin D cannot completely control chronic hypophosphatemia, leaving patients with incomplete healing and residual skeletal deformity as well as at risk of endocrine abnormalities and adverse drug reactions. However, understanding the pathophysiology has led to the development of a targeted therapy, burosumab, a fibroblast growth factor-23 inhibitor that was recently approved in Korea for the treatment of XLH. This review provides insight into the diagnosis, evaluation, treatment, and recommended follow-up for a typical case of XLH and reviews its pathophysiology.
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Affiliation(s)
- Eujin Park
- Department of Pediatrics, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea
| | - Hee Gyung Kang
- Department of Pediatrics, Seoul National University College of Medicine, Seoul, Korea
- Departments of Pediatrics, Seoul National University Children’s Hospital, Seoul, Korea
- Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul, Korea
- Wide River Institute of Immunology, Seoul National University, Hongcheon, Korea
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5
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Levy-Shraga Y, Levi S, Regev R, Gal S, Brener A, Lebenthal Y, Gillis D, Strich D, Zung A, Cleper R, Borovitz Y, Bello R, Tenenbaum A, Zadik Z, Davidovits M, Zeitlin L, Tiosano D. Linear growth of children with X-linked hypophosphatemia treated with burosumab: a real-life observational study. Eur J Pediatr 2023; 182:5191-5202. [PMID: 37707589 DOI: 10.1007/s00431-023-05190-y] [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: 06/16/2023] [Revised: 08/30/2023] [Accepted: 09/02/2023] [Indexed: 09/15/2023]
Abstract
To assess the long-term efficacy of burosumab for pediatric patients with X-linked hypophosphatemia, focusing on linear growth. This multi-center retrospective study included 35 pediatric patients who began treatment with burosumab between January 2018 and January 2021. We collected clinical data, anthropometric measurements, laboratory results, and Rickets Severity Score (RSS), from 2 years prior to treatment initiation and up to 4 years after. Burosumab was initiated at a mean age of 7.5 ± 4.4 years (range 0.6-15.9), with a mean initial dose of 0.8 ± 0.3 mg/kg, which was subsequently increased to 1.1 ± 0.4 mg/kg. The patients were followed for 2.9 ± 1.4 years (range 1-4) after initiating burosumab. Serum phosphorus levels increased from 2.7 ± 0.8 mg/dl at burosumab initiation to 3.4 ± 0.6 mg/dl after 3 months and remained stable (p < 0.001). Total reabsorption of phosphorus increased from 82.0 ± 6.8 to 90.1 ± 5.3% after 12 months of treatment (p = 0.041). The RSS improved from 1.7 ± 1.0 at burosumab initiation to 0.5 ± 0.6 and 0.3 ± 0.6 after 12 and 24 months, respectively (p < 0.001). Both height z-score and weight z-score improved from burosumab initiation to the end of the study: from - 2.07 ± 1.05 to - 1.72 ± 1.04 (p < 0.001) and from - 0.51 ± 1.12 to - 0.11 ± 1.29 (p < 0.001), respectively. Eight children received growth hormone combined with burosumab treatment. Height z-score improved among those who received growth hormone (from - 2.33 ± 1.12 to - 1.94 ± 1.24, p = 0.042) and among those who did not (from - 2.01 ± 1.01 to - 1.66 ± 1.01, p = 0.001). CONCLUSION Burosumab treatment in a real-life setting improved phosphate homeostasis and rickets severity and enhanced linear growth. WHAT IS KNOWN • Compared to conventional therapy, burosumab treatment has been shown to increase serum phosphate levels and reduce the severity of rickets. • The effect of burosumab on growth is still being study. WHAT IS NEW • Height z-score improved between the start of burosumab treatment and the end of the study (-2.07 ± 1.05 vs. -1.72 ± 1.04, p < 0.001). • Eight children received burosumab combined with growth hormone treatment without side effects during the concomitant treatments.
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Affiliation(s)
- Yael Levy-Shraga
- Pediatric Endocrinology Unit, The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Center, Tel Hashomer, 52621, Israel.
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
| | - Shelly Levi
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Institute of Pediatric Nephrology, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Ravit Regev
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Endocrinology and Diabetes Unit, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Shoshana Gal
- Division of Pediatric Endocrinology, Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
- Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Avivit Brener
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Endocrinology and Diabetes Unit, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Yael Lebenthal
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Endocrinology and Diabetes Unit, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - David Gillis
- Pediatric Endocrinology Unit, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
- Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Medical School, Jerusalem, Israel
| | - David Strich
- Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Medical School, Jerusalem, Israel
- Department of Pediatrics, Shaare Zedek Medical Center, Jerusalem, Israel
| | - Amnon Zung
- Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Medical School, Jerusalem, Israel
- Pediatrics Department, Kaplan Medical Center, Rehovot, Israel
| | - Roxana Cleper
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Nephrology Unit, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Yael Borovitz
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Institute of Pediatric Nephrology, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Rachel Bello
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shafer Institute for Endocrinology and Diabetes, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Ariel Tenenbaum
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- The Shafer Institute for Endocrinology and Diabetes, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Zvi Zadik
- Faculty of Medicine, Hebrew University of Jerusalem, Hadassah Medical School, Jerusalem, Israel
- Pediatrics Department, Kaplan Medical Center, Rehovot, Israel
| | - Miriam Davidovits
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Institute of Pediatric Nephrology, Schneider Children's Medical Center, Petah Tikva, Israel
| | - Leonid Zeitlin
- The Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Pediatric Orthopedic Department, Dana-Dwek Children's Hospital, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Dov Tiosano
- Division of Pediatric Endocrinology, Ruth Rappaport Children's Hospital, Rambam Medical Center, Haifa, Israel
- Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel
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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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7
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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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8
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Presentation and Diagnosis of Pediatric X-Linked Hypophosphatemia. ENDOCRINES 2023. [DOI: 10.3390/endocrines4010012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare type of hereditary hypophosphatemic rickets. Patients with XLH have various symptoms that lower their QOL as defined by HAQ, RAPID3, SF36-PCS, and SF36-MCS in adult patients and SF-10 and PDCOI in pediatric patients. Early diagnosis and treatment are needed to reduce the burden, but the condition is often diagnosed late in childhood. The present review aims to summarize the symptoms, radiological and biological characteristics, and long-term prognosis of pediatric XLH. Typical symptoms of XLH are lower leg deformities (age six months or later), growth impairment (first year of life or later), and delayed gross motor development with progressive lower limb deformities (second year of life or later). Other symptoms include dental abscess, bone pain, hearing impairment, and Chiari type 1 malformation. Critical, radiological findings of rickets are metaphyseal widening, cupping, and fraying, which tend to occur in the load-bearing bones. The Rickets Severity Score, validated for XLH, is useful for assessing the severity of rickets. The biochemical features of XLH include elevated FGF23, hypophosphatemia, low 1,25(OH)2D, and elevated urine phosphate. Renal phosphate wasting can be assessed using the tubular maximum reabsorption of phosphate per glomerular filtration rate (TmP/GFR), which yields low values in patients with XLH. XLH should be diagnosed early because the multisystem symptoms often worsen over time. The present review aims to help physicians diagnose XLH at an early stage.
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9
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Walker EYX, Lindsay TAJ, Allgrove J, Marlais M, Bockenhauer D, Hayes W. Burosumab in management of X-linked hypophosphataemia: a retrospective cohort study of growth and serum phosphate levels. Arch Dis Child 2023; 108:379-384. [PMID: 36717209 DOI: 10.1136/archdischild-2022-324962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/09/2023] [Indexed: 02/01/2023]
Abstract
BACKGROUND Burosumab, an antifibroblast growth factor 23 monoclonal antibody, improves rickets severity, symptoms and growth in children with X-linked hypophosphataemia (XLH) followed up to 64 weeks in clinical trials. International dosing guidance recommends targeting normal serum phosphate concentration; however, some children may not achieve this despite maximal dosing. This study compares clinical outcomes in children with XLH on long-term burosumab treatment who achieved normal phosphate versus those who did not. METHODS Single-centre retrospective review of a large paediatric cohort with XLH treated with burosumab. We evaluated growth and biochemical markers of bone health in those who did compared with those who did not achieve normal plasma phosphate concentration. RESULTS Fifty-five children with XLH with median age of 11.7 (IQR 6.8-15.5) years were included. 27 (49%) had low plasma phosphate concentration, and 27 (49%) had normal phosphate after a median burosumab treatment duration of 3.3 (IQR 2.6-3.7) years. 1 (2%) did not have a recent phosphate level recorded. No difference in growth was found between normal and abnormal phosphate groups (p=0.9). CONCLUSIONS Young children with XLH experience sustained growth on long-term burosumab treatment, although without normal plasma phosphate concentration in many. Consideration should be made to changing burosumab dosing recommendations to target normalisation of alkaline phosphatase, as opposed to plasma phosphate concentration.
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Affiliation(s)
- Emma Yi Xiu Walker
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | | | - Jeremy Allgrove
- Department of Endocrinology, Great Ormond Street Hospital For Children NHS Foundation Trust, London, UK
| | - Matko Marlais
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,Institute of Child Health, University College London, London, UK
| | - Detlef Bockenhauer
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.,Department of Renal Medicine, University College London, London, UK
| | - Wesley Hayes
- Department of Paediatric Nephrology, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK .,Institute of Child Health, University College London, London, UK
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10
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Larsson A, Regnstrand T, Skott P, Mäkitie O, Björnsdottir S, Garming-Legert K. Dental health of patients with X-linked hypophosphatemia: A controlled study. FRONTIERS IN ORAL HEALTH 2023; 4:1087761. [PMID: 37026091 PMCID: PMC10070686 DOI: 10.3389/froh.2023.1087761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 02/28/2023] [Indexed: 04/08/2023] Open
Abstract
Objective The present study compared the dental health of patients with X-linked hypophosphatemia (XLH) with healthy age- and gender-matched controls to increase our knowledge of the impact of XLH on oral health. Materials and methods Twenty-two adult patients with XLH in the Stockholm region of Sweden were referred to the Department of Orofacial Medicine at Karolinska Institutet for an extended clinical and radiological examination. Pre-existing radiologic examinations of 44 healthy age- and gender-matched controls were retrieved from the Department of Oral Radiology, at Karolinska Institutet. Results The 22 patients with XLH (15 females, median age 38 years, range 20-71; 7 males, median age 49 years, range 24-67) had a significantly higher number of root-filled teeth compared to healthy controls (p = .001). In the XLH group, females had significantly better oral health than males, especially concerning endodontic and cariological status (p's = .01 and .02, respectively). Periodontal status differed non-significantly between the XLH and control groups. Conclusion Patients with XLH had a significantly lower oral health status compared to a healthy population especially concerning endodontic conditions. Male patients with XLH had a higher risk of poor oral health compared to female patients with XLH.
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Affiliation(s)
- Amila Larsson
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
- Public Dental Health Service Stockholm AB, Stockholm, Sweden
- Correspondence: Amila Larsson
| | - Tobias Regnstrand
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Pia Skott
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
- Public Dental Health Service Stockholm AB, Stockholm, Sweden
| | - Outi Mäkitie
- Department of Pediatric Research, Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Department of Clinical Genetics, Clinical Genetics, Karolinska University Hospital, Stockholm, Sweden
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Sigridur Björnsdottir
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Endocrinology, Metabolism and Diabetes, Karolinska University Hospital, Stockholm, Sweden
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11
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LaValley MN, Zappi K, Guadix SW, Giantini-Larsen AM, Garton ALA, Heier LA, Imahiyerobo TA, Hoffman CE. Complications in craniosynostosis surgery in patients with rickets: illustrative case and systematic review of literature. JOURNAL OF NEUROSURGERY. CASE LESSONS 2022; 4:CASE22388. [PMID: 36536525 PMCID: PMC9764373 DOI: 10.3171/case22388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/25/2022] [Indexed: 12/23/2022]
Abstract
BACKGROUND Craniosynostosis (CSS) is the premature fusion of calvarial sutures associated with identified genetic mutations or secondary to alterations in intracranial pressure, brain, or bone growth patterns. Of the metabolic etiologies implicated in CSS, X-linked hypophosphatemic rickets (XLHR) is the most common, with dysfunctional bone mineralization leading to progressive hyperostosis and delayed synostosis. There is a paucity of literature discussing the unique surgical considerations for XLHR-related CSS. OBSERVATIONS A 26-month-old male with XLHR-related sagittal CSS underwent cranial vault remodeling (CVR). Surgery was complicated by the presence of diploic hypertrophy with significant intraoperative estimated blood loss (EBL). EBL greatly exceeded reference ranges for CVR in all-cause CSS. As a result, the surgical goals were modified and the complete planned procedure aborted. Subsequent review of preoperative imaging revealed multiple fine vascular lacunae within the bone. A systematic literature review was conducted to identify reported complications relating to surgical intervention for rickets-associated CSS. LESSONS Future considerations for patients with XLHR-related CSS should emphasize awareness of metabolic risk factors with associated complications, and the need for selection of approach and operative management techniques to avoid EBL. Further research is required to elucidate underlying mechanisms and determine whether the encountered phenomenon is characteristic across this patient population and potentially minimized by preoperative medical therapy.
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Affiliation(s)
- Myles N. LaValley
- Department of Plastic Surgery, Columbia University Medical Center, New York, New York
| | | | | | | | | | - Linda A. Heier
- Radiology, Weill Cornell Medical Center, New York, New York; and
| | - Thomas A. Imahiyerobo
- Department of Plastic Surgery, Columbia University Medical Center, New York, New York
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12
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Charoenngam N, Nasr A, Shirvani A, Holick MF. Hereditary Metabolic Bone Diseases: A Review of Pathogenesis, Diagnosis and Management. Genes (Basel) 2022; 13:genes13101880. [PMID: 36292765 PMCID: PMC9601711 DOI: 10.3390/genes13101880] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 10/03/2022] [Accepted: 10/13/2022] [Indexed: 11/20/2022] Open
Abstract
Hereditary metabolic bone diseases are characterized by genetic abnormalities in skeletal homeostasis and encompass one of the most diverse groups among rare diseases. In this review, we examine 25 selected hereditary metabolic bone diseases and recognized genetic variations of 78 genes that represent each of the three groups, including sclerosing bone disorders, disorders of defective bone mineralization and disorder of bone matrix and cartilage formation. We also review pathophysiology, manifestation and treatment for each disease. Advances in molecular genetics and basic sciences has led to accurate genetic diagnosis and novel effective therapeutic strategies for some diseases. For other diseases, the genetic basis and pathophysiology remain unclear. Further researches are therefore crucial to innovate ways to overcome diagnostic challenges and develop effective treatment options for these orphan diseases.
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Affiliation(s)
- Nipith Charoenngam
- Section Endocrinology, Diabetes, Nutrition and Weight Management, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Department of Medicine, Mount Auburn Hospital, Harvard Medical School, Cambridge, MA 02138, USA
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
| | - Aryan Nasr
- Section Endocrinology, Diabetes, Nutrition and Weight Management, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Arash Shirvani
- Section Endocrinology, Diabetes, Nutrition and Weight Management, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
| | - Michael F. Holick
- Section Endocrinology, Diabetes, Nutrition and Weight Management, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
- Correspondence: ; Tel.: +1-617-358-6139
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13
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Brandi ML, Ariceta G, Beck-Nielsen SS, Boot AM, Briot K, de Lucas Collantes C, Emma F, Giannini S, Haffner D, Keen R, Levtchenko E, Mӓkitie O, Nilsson O, Schnabel D, Tripto-Shkolnik L, Zillikens MC, Liu J, Tudor A, Mughal MZ. Post-authorisation safety study of burosumab use in paediatric, adolescent and adult patients with X-linked hypophosphataemia: rationale and description. Ther Adv Chronic Dis 2022; 13:20406223221117471. [PMID: 36082134 PMCID: PMC9445456 DOI: 10.1177/20406223221117471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 07/15/2022] [Indexed: 11/16/2022] Open
Abstract
Background: X-linked hypophosphataemia (XLH) is a rare, inherited, phosphate-wasting disorder that elevates fibroblast growth factor 23 (FGF23), causing renal phosphate-wasting and impaired active vitamin D (1,25(OH)2D) synthesis. Disease characteristics include rickets, osteomalacia, odontomalacia, and short stature. Historically, treatment has been oral phosphate and 1,25(OH)2D supplements. However, these treatments do not correct the primary pathogenic mechanism or treat all symptoms and can be associated with adverse effects. Burosumab is a recombinant human immunoglobulin G1 monoclonal antibody against FGF23, approved for treating XLH in several geographical regions, including Europe and Israel. Burosumab restores normal serum phosphate levels, minimising the clinical consequences of XLH. Safety data on long-term treatment with burosumab are lacking owing to the rarity of XLH. This post-authorisation safety study (PASS) aims to evaluate the safety outcomes in patients aged >1 year. Methods: The PASS is a 10-year retrospective and prospective cohort study utilising data from the International XLH Registry (NCT03193476), which includes standard diagnostic and monitoring practice data at participating centres. The PASS aims to evaluate frequency and severity of safety outcomes, frequency and outcomes of pregnancies in female patients, and safety outcomes in patients with mild to moderate kidney disease at baseline, in children, adolescents and adults treated with burosumab for XLH. It is expected that there will be at least 400 patients who will be administered burosumab. Results: Data collection started on 24 April 2019. The expected date of the final study report is 31 December 2028, with two interim reports. Conclusion: This PASS will provide data on the long-term safety of burosumab treatment for XLH patients and describe safety outcomes for patients receiving burosumab contrasted with those patients receiving other XLH treatments, to help inform the future management of XLH patients. The PASS will be the largest real-world safety study of burosumab. Registry identification: The International XLH Registry is registered with clinicaltrials.gov as NCT03193476 (https://clinicaltrials.gov/ct2/show/NCT03193476), and the PASS is registered with the European Union electronic Register of Post-Authorisation Studies as EUPAS32190 (http://www.encepp.eu/encepp/viewResource.htm?id=32191).
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Affiliation(s)
| | - Gema Ariceta
- Department of Pediatric Nephrology, Hospital Universitario Vall d'Hebron, Universidad Autónoma de Barcelona, Barcelona, Spain
| | - Signe Sparre Beck-Nielsen
- Centre for Rare Diseases, Department of Paediatrics, Aarhus University Hospital, Aarhus, Denmark.,Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Annemieke M Boot
- Department of Pediatric Endocrinology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Karine Briot
- APHP, Department of Rheumatology, Cochin Hospital, Université de Paris, Paris, France
| | - Carmen de Lucas Collantes
- Department of Nephrology, Hospital Infantil Universitario Niño Jesús, Universidad Autónoma de Madrid, Madrid, Spain
| | - Francesco Emma
- Division of Nephrology, Bambino Gesù Children's Hospital IRCCS, Rome, Italy
| | - Sandro Giannini
- Department of Medicine, Clinica Medica 1, University of Padua, Padua, Italy
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Children's Hospital, Hannover Medical School, Hannover, Germany
| | - Richard Keen
- Metabolic Unit, Royal National Orthopaedic Hospital NHS Trust, London, UK
| | - Elena Levtchenko
- Department of Pediatric Nephrology and Development and Regeneration, University Hospitals Leuven, University of Leuven, Leuven, Belgium
| | - Outi Mӓkitie
- Pediatric Endocrinology, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Ola Nilsson
- Division of Pediatric Endocrinology, Department of Women's and Children's Health, Karolinska Institutet and University Hospital, Stockholm, Sweden.,Department of Medical Sciences and Department of Pediatrics, Örebro University and University Hospital, Örebro, Sweden
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charitè, University Medicine, Berlin, Germany
| | - Liana Tripto-Shkolnik
- Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.,Division of Endocrinology, Diabetes and Metabolism, Sheba Medical Center, Tel-Hashomer, Israel
| | - M Carola Zillikens
- Department of Internal Medicine, Erasmus MC Bone Center - Erasmus University Medical Center, Rotterdam, The Netherlands
| | | | | | - M Zulf Mughal
- Department of Paediatric Endocrinology, Royal Manchester Children's Hospital, Manchester, UK.,Faculty of Biology, Medicine & Health, University of Manchester, Manchester, UK
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14
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Treatment of X-Linked Hypophosphatemia in Children. ENDOCRINES 2022. [DOI: 10.3390/endocrines3030042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The conventional treatment for X-linked hypophosphatemia (XLH), consisting of phosphorus supplementation and a biologically active form of vitamin D (alfacalcidol or calcitriol), is used to treat rickets and leg deformities and promote growth. However, patients’ adult height often remains less than −2 SD. Moreover, adverse events, such as renal calcification and hyperparathyroidism, may occur. The main pathology in XLH is caused by excessive production of fibroblast growth factor 23 (FGF23). Several studies have demonstrated that treatment with burosumab, a blocking neutralizing antibody against FGF23, is better than conventional therapy for severe XLH and has no serious, short-term side effects. Thus, treatment with burosumab may be an option for severe XLH. The present article reviews the conventional and burosumab therapies. In addition to the fact that the long-term efficacy of antibody-based treatment has not been demonstrated, there are other, unresolved issues concerning the burosumab treatment of XLH.
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15
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Pathogenic Variants of the PHEX Gene. ENDOCRINES 2022. [DOI: 10.3390/endocrines3030040] [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
Twenty-five years ago, a pathogenic variant of the phosphate-regulating endopeptidase homolog X-linked (PHEX) gene was identified as the cause of X-linked hypophosphatemic rickets (XLH). Subsequently, the overproduction of fibroblast growth factor 23 (FGF23) due to PHEX defects has been found to be associated with XLH pathophysiology. However, the mechanism by which PHEX deficiency contributes to the upregulation of FGF23 and the function of PHEX itself remain unclear. To date, over 700 pathogenic variants have been identified in patients with XLH, and functional assays and genotype–phenotype correlation analyses based on pathogenic variant data derived from XLH patients have been reported. Genetic testing for XLH is useful for the diagnosis. Not only have single-nucleotide variants causing missense, nonsense, and splicing variants and small deletion/insertion variants causing frameshift/non-frameshift alterations been observed, but also gross deletion/duplication variants causing copy number variants have been reported as pathogenic variants in PHEX. With the development of new technologies including next generation sequencing, it is expected that an increasing number of pathogenic variants will be identified. This chapter aimed to summarize the genotype of PHEX and related analyses and discusses the pathophysiology of PHEX defects to seek clues on unsolved questions.
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16
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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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17
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Trombetti A, Al-Daghri N, Brandi ML, Cannata-Andía JB, Cavalier E, Chandran M, Chaussain C, Cipullo L, Cooper C, Haffner D, Harvengt P, Harvey NC, Javaid MK, Jiwa F, Kanis JA, Laslop A, Laurent MR, Linglart A, Marques A, Mindler GT, Minisola S, Yerro MCP, Rosa MM, Seefried L, Vlaskovska M, Zanchetta MB, Rizzoli R. Interdisciplinary management of FGF23-related phosphate wasting syndromes: a Consensus Statement on the evaluation, diagnosis and care of patients with X-linked hypophosphataemia. Nat Rev Endocrinol 2022; 18:366-384. [PMID: 35484227 DOI: 10.1038/s41574-022-00662-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/10/2022] [Indexed: 12/17/2022]
Abstract
X-linked hypophosphataemia (XLH) is the most frequent cause of hypophosphataemia-associated rickets of genetic origin and is associated with high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23). In addition to rickets and osteomalacia, patients with XLH have a heavy disease burden with enthesopathies, osteoarthritis, pseudofractures and dental complications, all of which contribute to reduced quality of life. This Consensus Statement presents the outcomes of a working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, and provides robust clinical evidence on management in XLH, with an emphasis on patients' experiences and needs. During growth, conventional treatment with phosphate supplements and active vitamin D metabolites (such as calcitriol) improves growth, ameliorates leg deformities and dental manifestations, and reduces pain. The continuation of conventional treatment in symptom-free adults is still debated. A novel therapeutic approach is the monoclonal anti-FGF23 antibody burosumab. Although promising, further studies are required to clarify its long-term efficacy, particularly in adults. Given the diversity of symptoms and complications, an interdisciplinary approach to management is of paramount importance. The focus of treatment should be not only on the physical manifestations and challenges associated with XLH and other FGF23-mediated hypophosphataemia syndromes, but also on the major psychological and social impact of the disease.
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Affiliation(s)
- Andrea Trombetti
- Division of Bone Diseases, Department of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
- Division of Geriatrics, Department of Rehabilitation and Geriatrics, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland
| | - Nasser Al-Daghri
- Chair for Biomarkers of Chronic Diseases, Biochemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | | | - Jorge B Cannata-Andía
- Hospital Universitario Central de Asturias (HUCA), Oviedo, Spain
- Universidad de Oviedo, Oviedo, Spain
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Spain
- Retic REDinREN-RICORS, 2040-ISCIII, Madrid, Spain
| | - Etienne Cavalier
- Department of Clinical Chemistry, University of Liege, CHU de Liège, Liège, Belgium
| | - Manju Chandran
- Complicated Metabolic Bone Disorders Clinic, Osteoporosis and Bone Metabolism Unit, Department of Endocrinology, Singapore General Hospital, Singapore, Singapore
| | - Catherine Chaussain
- Université de Paris, Institut des maladies musculo-squelettiques, URP2496, UFR Odontologie, Montrouge, France
- AP-HP, FHU DDS-Net, Centre de Référence des Maladies Rares du Métabolisme du Calcium et du Phosphore, Service médecine bucco-dentaire, Hôpital Bretonneau, GH Paris Nord Université de Paris, Paris, France
| | - Lucia Cipullo
- Patient representative with XLH, Geneva, Switzerland
| | - Cyrus Cooper
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
- NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
| | - Dieter Haffner
- Department of Paediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Pol Harvengt
- XLH Belgium, Belgian association of patients with XLH (a member of the International XLH Alliance), Waterloo, Belgium
| | - Nicholas C Harvey
- MRC Lifecourse Epidemiology Centre, University of Southampton, Southampton, UK
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | | | - Famida Jiwa
- Chair of the Committee of Patients Societies at the International Osteoporosis Foundation, Osteoporosis Canada, Toronto, Canada
| | - John A Kanis
- Mary McKillop Institute for Health Research, Australian Catholic University, Melbourne, Australia
- Centre for Metabolic Bone Diseases, University of Sheffield Medical School, Sheffield, UK
| | - Andrea Laslop
- Scientific Office, Federal Office for Safety in Health Care, Vienna, Austria
| | - Michaël R Laurent
- Centre for Metabolic Bone Diseases, University Hospitals Leuven, Leuven, Belgium
| | - Agnès Linglart
- Paris-Saclay University, INSERM U1185, Le Kremlin-Bicêtre, France
- AP-HP, endocrinology and diabetes for children, Reference centre for rare diseases of calcium and phosphate metabolism, OSCAR network, Platform of expertise for rare diseases of Paris Saclay Hospital, Bicêtre Paris Saclay Hospital, Le Kremlin-Bicêtre, France
| | - Andréa Marques
- Rheumatology Department, Centro Hospitalar Universitário de Coimbra, Coimbra, Portugal
- Health Sciences Research Unit: Nursing (UICiSA:E), Nursing School of Coimbra, Coimbra, Portugal
| | - Gabriel T Mindler
- Department of Paediatric Orthopaedics, Orthopaedic Hospital Speising, Vienna, Austria
- Vienna Bone and Growth Center, Vienna, Austria
| | - Salvatore Minisola
- Department of Clinical, Internal, Anaesthesiologic and Cardiovascular Sciences, 'Sapienza', Rome University, Rome, Italy
| | | | - Mario Miguel Rosa
- Departamento de Neurociências, Laboratório de Farmacologia Clínica E Terapêutica Faculdade de Medicina da Universidade de Lisboa, Lisbon, Portugal
| | - Lothar Seefried
- Orthopedic Department, University of Würzburg, Würzburg, Germany
| | - Mila Vlaskovska
- Medical Faculty, Department of Pharmacology, Medical University Sofia, Sofia, Bulgaria
| | - María Belén Zanchetta
- Instituto de Investigaciones Metabólicas (IDIM), Universidad del Salvador, Buenos Aires, Argentina
| | - René Rizzoli
- Division of Bone Diseases, Department of Medicine, Geneva University Hospitals and Faculty of Medicine, Geneva, Switzerland.
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Abstract
A number of genes that cause inherited kidney disorders reside on the X chromosome. Given that males have only a single active X chromosome, these disorders clinically manifest primarily in men and boys. However, phenotypes in female carriers of X-linked kidney conditions are becoming more and more recognized. This article reviews the biology of X inactivation as well as the kidney phenotype in women and girls with a number of X-linked kidney disorders including Alport syndrome, Fabry disease, nephrogenic diabetes insipidus, X-linked hypophosphatemic rickets, Dent disease, and Lowe syndrome.
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Affiliation(s)
- Catherine Quinlan
- Department of Nephrology, Royal Children's Hospital, Melbourne, Victoria, Australia; Department of Kidney Regeneration, Murdoch Children's Research Institute, Melbourne, Victoria, Australia; Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia
| | - Michelle N Rheault
- Division of Pediatric Nephrology, Department of Pediatrics, University of Minnesota Masonic Children's Hospital, Minneapolis, MN.
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19
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Alikasifoglu A, Unsal Y, Gonc EN, Ozon ZA, Kandemir N, Alikasifoglu M. Long-term effect of conventional phosphate and calcitriol treatment on metabolic recovery and catch-up growth in children with PHEX mutation. J Pediatr Endocrinol Metab 2021; 34:1573-1584. [PMID: 34525271 DOI: 10.1515/jpem-2021-0387] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/30/2021] [Indexed: 11/15/2022]
Abstract
OBJECTIVES Hereditary hypophosphatemic rickets (HR) is conventionally treated with phosphate and calcitriol. Exploring genotype and phenotypic spectrum of X-linked hypophosphatemic rickets (XLHR), focusing on short-term, long-term, and pubertal impact of conventional treatment was aimed. METHODS Sixteen patients from 12 unrelated families with HR were analyzed for phosphate regulating endopeptidase homolog X-linked (PHEX) mutation. Initially Sanger sequencing analysis was performed. If PHEX mutation was not detected, multiplex ligation-dependent probe amplification (MLPA) was performed. If molecular defect was detected, first-degree relatives were analyzed. Thirteen patients (81%) and five first-degree relatives with XLHR were evaluated for genotype-phenotype or gender-phenotype correlation. Clinical characteristics and response to conventional treatment were determined retrospectively. RESULTS Nine different PHEX mutations were identified; four splice-site, three point mutations, and two single exon deletions. Four were novel mutations. Despite conventional treatment, median adult height was lower than median height on admission (-3.8 and -2.3 SDS, respectively), metabolic and radiographic recovery were not achieved, adherence was low (30%). Although mean adult height was better in compliant patients than noncompliants (-2.6 vs. -3.7 SDS, respectively), they were still short. Correlation between phenotype and genotype or gender could not be shown. Median phosphate decreased significantly throughout puberty (p=0.014). Median pubertal height was lower than prepubertal height (-4.4 vs. -3.6 SDS; respectively), pubertal growth spurt was not observed. Among five patients with a follow-up longer than five years, three had nephrocalcinosis (60%), two had hyperparathyroidism (40%), 4/6 (33%) required correction osteotomy. CONCLUSIONS Conventional treatment appears to have limited effect on metabolic, clinical and radiographic recovery in XLHR. Metabolic control and growth worsened during puberty. Although, long-term adverse effects are yet to be seen, introduction of burosumab as first-line treatment may be an alternative after infancy.
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Affiliation(s)
- Ayfer Alikasifoglu
- Division of Pediatric Endocrinology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Yagmur Unsal
- Division of Pediatric Endocrinology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Elmas Nazli Gonc
- Division of Pediatric Endocrinology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Zeynep Alev Ozon
- Division of Pediatric Endocrinology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Nurgun Kandemir
- Division of Pediatric Endocrinology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Mehmet Alikasifoglu
- Division of Medical Genetics, Department of Medical Genetics, Hacettepe University Faculty of Medicine, Ankara, Turkey
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20
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Ishihara Y, Ohata Y, Takeyari S, Kitaoka T, Fujiwara M, Nakano Y, Yamamoto K, Yamada C, Yamamoto K, Michigami T, Mabe H, Yamaguchi T, Matsui K, Tamada I, Namba N, Yamamoto A, Etoh J, Kawaguchi A, Kosugi R, Ozono K, Kubota T. Genotype-phenotype analysis, and assessment of the importance of the zinc-binding site in PHEX in Japanese patients with X-linked hypophosphatemic rickets using 3D structure modeling. Bone 2021; 153:116135. [PMID: 34333162 DOI: 10.1016/j.bone.2021.116135] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/09/2021] [Accepted: 07/26/2021] [Indexed: 11/25/2022]
Abstract
X-linked hypophosphatemic rickets (XLH) is an inheritable type of rickets caused by inactivating variants in the phosphate regulating endopeptidase homolog X-linked (PHEX) gene, which results in the overproduction of fibroblast growth factor 23 (FGF23). The mechanism by which PHEX impairment leads to FGF23 overproduction is unknown. Because little is known regarding the genotype-phenotype correlation in Japanese XLH, we summarized the available clinical and genetic data and analyzed the genotype-phenotype relationships using 3-dimensional (3D) structure modeling to clarify the XLH pathophysiology. We retrospectively reviewed the clinical features and performed genetic analysis of 39 Japanese patients with XLH from 28 unrelated pedigrees carrying any known or novel PHEX variant. To predict changes in the 3D structure of mutant PHEX, we constructed a putative 3D model of each mutant and evaluated the effect of structural alteration by genotype-phenotype correlation analysis. Genetic analysis revealed 23 PHEX variants, including eight novel variants. They were associated with high i-FGF23 levels, hypophosphatemia, phosphaturia, high alkaline phosphatase levels, and short stature. No gene dosage effect or genotype-phenotype correlation was observed when truncating and non-truncating variants were compared. However, the conservation of the zinc-binding site and cavity in PHEX had an impact on the elevation of i-FGF23 levels. Via genotype-phenotype relationship analysis using 3D modeling, we showed that the zinc-binding site and cavity in PHEX can play a critical role in its function. These findings provide new genetic clues for investigating the function of PHEX and the pathogenesis of XLH.
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Affiliation(s)
- Yasuki Ishihara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan; The 1st. Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Japan; Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yasuhisa Ohata
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Shinji Takeyari
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Taichi Kitaoka
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Makoto Fujiwara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan; The 1st. Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Yukako Nakano
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kenichi Yamamoto
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan; Department of Statistical Genetics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Chieko Yamada
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Katsusuke Yamamoto
- Department of Pediatric Nephrology and Metabolism, Osaka Women's and Children's Hospital, Izumi, Japan
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Osaka Women's and Children's Hospital, Izumi, Japan
| | - Hiroyo Mabe
- Department of Pediatrics, Kumamoto University Hospital, Kumamoto, Japan
| | - Takeshi Yamaguchi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Sapporo, Japan
| | - Katsuyuki Matsui
- Department of Pediatrics, Shiga University of Medical Science, Otsu, Japan
| | - Izumi Tamada
- Department of Pediatrics, Imakiire General Hospital, Kagoshima, Japan
| | - Noriyuki Namba
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan; Division of Pediatrics and Perinatology, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Akiko Yamamoto
- Department of Pediatrics, Kumamoto Chuo Hospital, Kumamoto, Japan
| | - Junya Etoh
- Department of Pediatrics, Saga-Ken Medical Centre Koseikan, Saga, Japan
| | - Azusa Kawaguchi
- Department of Pediatrics, National Hospital Organization Hokkaido Medical Center, Sapporo, Japan
| | - Rieko Kosugi
- Department of Diabetes and Endocrinology, Shizuoka General Hospital, Shizuoka, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takuo Kubota
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan.
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21
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Yang D, Ren X, Lu Y, Han J. Current diagnosis and management of rare pediatric diseases in China. Intractable Rare Dis Res 2021; 10:223-237. [PMID: 34877234 PMCID: PMC8630464 DOI: 10.5582/irdr.2021.01134] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/06/2021] [Accepted: 11/08/2021] [Indexed: 12/22/2022] Open
Abstract
This review categorizes and summarizes the rare pediatric diseases that have been included in the First List of Rare Diseases that was jointly published by the National Health Commission and four other government departments in China in 2018. In total, 58 diseases that develop during childhood are included. These diseases involve nine organ systems, including the musculoskeletal, respiratory, immune, endocrine and metabolic, nervous, cardiovascular, hematological, urinary, and integumentary systems. Affected children often have multiorgan involvement with various presentations. Severe diseases can cause acute symptoms starting in the neonatal period that lead to increased morbidity and mortality without prompt management. Early diagnosis and treatment can significantly change the course of a disease and improve its prognosis. This work systemically reviews the status of rare pediatric diseases with a relatively high incidence in the First List of Rare Diseases.
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Affiliation(s)
- Dan Yang
- Department of Endocrinology, The First Hospital Affiliated with Shandong First Medical University, Ji'nan, China
- National Health Commission Key Laboratory for Biotech-Drugs, Shandong Province Key Laboratory for Rare & Uncommon Diseases, Biomedical Sciences College, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Xiuzhi Ren
- Department of Orthopaedic Surgery, The People's Hospital of Wuqing District, Tianjin, China
| | - Yanqin Lu
- Department of Endocrinology, The First Hospital Affiliated with Shandong First Medical University, Ji'nan, China
- National Health Commission Key Laboratory for Biotech-Drugs, Shandong Province Key Laboratory for Rare & Uncommon Diseases, Biomedical Sciences College, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
| | - Jinxiang Han
- Department of Endocrinology, The First Hospital Affiliated with Shandong First Medical University, Ji'nan, China
- National Health Commission Key Laboratory for Biotech-Drugs, Shandong Province Key Laboratory for Rare & Uncommon Diseases, Biomedical Sciences College, Shandong First Medical University & Shandong Academy of Medical Sciences, Ji'nan, China
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22
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Musthaffa Y, Conwell LS. Hypophosphataemic rickets: The long and short of it. J Paediatr Child Health 2021; 57:1519-1523. [PMID: 33233026 DOI: 10.1111/jpc.15277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2019] [Revised: 10/07/2020] [Accepted: 11/03/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Yassmin Musthaffa
- Department of Endocrinology and Diabetes, Queensland Children's Hospital, Brisbane, Queensland, Australia.,School of Clinical Medicine, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
| | - Louise S Conwell
- Department of Endocrinology and Diabetes, Queensland Children's Hospital, Brisbane, Queensland, Australia.,School of Clinical Medicine, Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia
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23
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Bacchetta J, Rothenbuhler A, Gueorguieva I, Kamenicky P, Salles JP, Briot K, Linglart A. X-linked hypophosphatemia and burosumab: Practical clinical points from the French experience. Joint Bone Spine 2021; 88:105208. [PMID: 34102329 DOI: 10.1016/j.jbspin.2021.105208] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/14/2021] [Indexed: 10/21/2022]
Abstract
Hereditary hypophosphatemia with increased FGF23 levels are rare inherited metabolic diseases characterized by low serum phosphate because of impaired renal tubular phosphate reabsorption. The most common form is X-linked hypophosphatemia (XLH), secondary to a mutation in the PHEX gene. In children, XLH is often manifested by rickets, delayed development of gait, lower limb deformities, growth retardation, craniosynostosis, and spontaneous dental abscesses. In adults, patients present diffuse musculoskeletal pain (bone and joints), early osteoarthritis, entesopathies, pseudo-fractures, muscular weakness, and severe dental damage. Conventional medical management is based on the combined administration of oral phosphate supplementation with active vitamin D analogs. Treatment with the recently approved anti-FGF23 burosumab is an alternative, especially in severe forms. Burosumab restores phosphate reabsorption in the proximal tubule and stimulates the endogenous synthesis of calcitriol. In Europe, burosumab has been approved for the treatment of XLH with radiographic evidence of bone disease in pediatric patients from one year of age and in adults. This manuscript will discuss the specific management of burosumab in children and adolescents in daily practice.
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Affiliation(s)
- Justine Bacchetta
- Reference Center for Rare Renal Diseases, Department of Pediatric Nephrology, Rheumatology and Dermatology, Nephrogones, Filière ORKiD, HFME, Lyon University Hospital, Lyon, France; Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, Filière OSCAR, HFME, Lyon University Hospital, Lyon, France
| | - Anya Rothenbuhler
- AP-HP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France; AP-HP, Endocrinology and Diabetes for Children, Bicêtre Paris-Sud Hospital, Le Kremlin-Bicêtre, France
| | - Iva Gueorguieva
- Pediatric Department, Endocrinology Unit, Children's Center, Lille University Hospital, Jeanne-de-Flandre Hospital, Lille, France
| | - Peter Kamenicky
- AP-HP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France; AP-HP, Department of Endocrinology and Reproductive Diseases, Bicêtre Paris-Sud Hospital, Paris, France
| | - Jean-Pierre Salles
- Unit of Endocrinology, Bone Diseases, Genetics and Gynecology, Children's Hospital, Toulouse University Hospital, 31059 Toulouse cedex 09, France; Toulouse-Purpan Pathophysiology Center, CPTP, INSERM UMR 1043, Paul-Sabatier University, Toulouse, France
| | - Karine Briot
- AP-HP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France; AP-HP, Department of Rheumatology, Cochin Hospital, Paris, France
| | - Agnès Linglart
- AP-HP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France; AP-HP, Endocrinology and Diabetes for Children, Bicêtre Paris-Sud Hospital, Le Kremlin-Bicêtre, France.
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24
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Sweeney NM, Nahas SA, Chowdhury S, Batalov S, Clark M, Caylor S, Cakici J, Nigro JJ, Ding Y, Veeraraghavan N, Hobbs C, Dimmock D, Kingsmore SF. Rapid whole genome sequencing impacts care and resource utilization in infants with congenital heart disease. NPJ Genom Med 2021; 6:29. [PMID: 33888711 PMCID: PMC8062477 DOI: 10.1038/s41525-021-00192-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 03/19/2021] [Indexed: 11/09/2022] Open
Abstract
Congenital heart disease (CHD) is the most common congenital anomaly and a major cause of infant morbidity and mortality. While morbidity and mortality are highest in infants with underlying genetic conditions, molecular diagnoses are ascertained in only ~20% of cases using widely adopted genetic tests. Furthermore, cost of care for children and adults with CHD has increased dramatically. Rapid whole genome sequencing (rWGS) of newborns in intensive care units with suspected genetic diseases has been associated with increased rate of diagnosis and a net reduction in cost of care. In this study, we explored whether the clinical utility of rWGS extends to critically ill infants with structural CHD through a retrospective review of rWGS study data obtained from inpatient infants < 1 year with structural CHD at a regional children's hospital. rWGS diagnosed genetic disease in 46% of the enrolled infants. Moreover, genetic disease was identified five times more frequently with rWGS than microarray ± gene panel testing in 21 of these infants (rWGS diagnosed 43% versus 10% with microarray ± gene panels, p = 0.02). Molecular diagnoses ranged from syndromes affecting multiple organ systems to disorders limited to the cardiovascular system. The average daily hospital spending was lower in the time period post blood collection for rWGS compared to prior (p = 0.003) and further decreased after rWGS results (p = 0.000). The cost was not prohibitive to rWGS implementation in the care of this cohort of infants. rWGS provided timely actionable information that impacted care and there was evidence of decreased hospital spending around rWGS implementation.
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Affiliation(s)
- Nathaly M Sweeney
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA.
- Rady Children's Hospital, San Diego, CA, USA.
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
| | - Shareef A Nahas
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Shimul Chowdhury
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Sergey Batalov
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Michelle Clark
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Sara Caylor
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Julie Cakici
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
- Department of Family Medicine and Public Health, University of California San Diego, La Jolla, CA, USA
| | - John J Nigro
- Rady Children's Hospital, San Diego, CA, USA
- Department of Surgery, University of California San Diego, La Jolla, CA, USA
| | - Yan Ding
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | | | - Charlotte Hobbs
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - David Dimmock
- Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
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25
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Abstract
Great strides over the past few decades have increased our understanding of the pathophysiology of hypophosphatemic disorders. Phosphate is critically important to a variety of physiologic processes, including skeletal growth, development and mineralization, as well as DNA, RNA, phospholipids, and signaling pathways. Consequently, hypophosphatemic disorders have effects on multiple systems, and may cause a variety of nonspecific signs and symptoms. The acute effects of hypophosphatemia include neuromuscular symptoms and compromise. However, the dominant effects of chronic hypophosphatemia are the effects on musculoskeletal function including rickets, osteomalacia and impaired growth during childhood. While the most common causes of chronic hypophosphatemia in children are congenital, some acquired conditions also result in hypophosphatemia during childhood through a variety of mechanisms. Improved understanding of the pathophysiology of these congenital conditions has led to novel therapeutic approaches. This article will review the pathophysiologic causes of congenital hypophosphatemia, their clinical consequences and medical therapy.
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Affiliation(s)
- Erik Allen Imel
- Division of Endocrinology, Departments of Medicine and Pediatrics, Indiana University School of Medicine, 1120 West Michigan Street, Gatch Building Room 365, Indianapolis, IN, 46112, USA.
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26
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Lin Y, Xu J, Li X, Sheng H, Su L, Wu M, Cheng J, Huang Y, Mao X, Zhou Z, Zhang W, Li C, Cai Y, Wu D, Lu Z, Yin X, Zeng C, Liu L. Novel variants and uncommon cases among southern Chinese children with X-linked hypophosphatemia. J Endocrinol Invest 2020; 43:1577-1590. [PMID: 32253725 DOI: 10.1007/s40618-020-01240-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 03/24/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE X-linked hypophosphatemia (XLH) is the most common inherited renal phosphate wasting disorder and is often misdiagnosed as vitamin D deficiency. This study aims to provide clinical and mutational characteristics of 65 XLH pediatric patients in southern China. METHODS In this work, a combination of DNA sequencing and qPCR analysis was used to study the PHEX gene in 80 pediatric patients diagnosed with hypophosphatemia. The clinical and laboratory data of confirmed 65 XLH patients were assessed and analyzed retrospectively. RESULTS In 65 XLH patients from 61 families, 51 different variants in the PHEX gene were identified, including 23 previously reported variants and 28 novel variants. In this cohort of XLH patients, the c.1601C>T(p.Pro534Leu) variant appears more frequently. Fourteen uncommon XLH cases were described, including four boys with de novo mosaic variants, eight patients with large deletions and a pair of monozygotic twins. The clinical manifestations in this cohort are very similar to those previously reported. CONCLUSION This study extends the mutational spectrum of the PHEX gene, which will contribute to accurate diagnosis. This study also suggests a supplementary qPCR or MLPA assay may be performed along with classical sequencing to confirm the gross insertion/deletion.
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Affiliation(s)
- Y Lin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - J Xu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - H Sheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - L Su
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - M Wu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - J Cheng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Y Huang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Mao
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Z Zhou
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - W Zhang
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - C Li
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Y Cai
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - D Wu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - Z Lu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - X Yin
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China
| | - C Zeng
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China.
| | - L Liu
- Department of Genetics and Endocrinology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, 9 Jinsui Rd., Guangzhou, 510623, China.
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Abstract
PURPOSE OF REVIEW The goal of this review is to give an overview of diagnosis and up-to-date management of major pediatric metabolic bone diseases that are associated with bone fragility, including nutritional rickets, hypophosphatemic rickets, osteogenesis imperfecta, Ehlers--Danlos syndrome, Marfan's syndrome, hypophosphatasia, osteopetrosis and skeletal fluorosis. RECENT FINDINGS During the past decade, a number of advanced treatment options have been introduced and shown to be an effective treatment in many metabolic bone disorders, such as burosumab for hypophosphatemic rickets and asfotase alfa for hypophosphatasia. On the other hand, other disorders, such as nutritional rickets and skeletal fluorosis continue to be underrecognized in many regions of the world. Genetic disorders of collagen-elastin, such as osteogenesis imperfecta, Ehlers--Danlos syndrome and Marfan's syndrome are also associated with skeletal fragility, which can be misdiagnosed as caused by non-accidental trauma/child abuse. SUMMARY It is essential to provide early and accurate diagnosis and treatment for pediatric patients with metabolic bone disorders in order to maintain growth and development as well as prevent fractures and metabolic complications.
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Kubota T, Fukumoto S, Cheong HI, Michigami T, Namba N, Ito N, Tokunaga S, Gibbs Y, Ozono K. Long-term outcomes for Asian patients with X-linked hypophosphataemia: rationale and design of the SUNFLOWER longitudinal, observational cohort study. BMJ Open 2020; 10:e036367. [PMID: 32601114 PMCID: PMC7328740 DOI: 10.1136/bmjopen-2019-036367] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION X-linked hypophosphataemic rickets/osteomalacia (XLH) is a chronic, debilitating genetic disease characterised by skeletal abnormalities and growth disorder. The burden of XLH begins in childhood and continues throughout life. Conventional medical therapy with phosphate, active vitamin D and surgery do not address the underlying pathophysiology of the disease. While treatment during childhood may improve bone deformity and growth retardation, a large proportion of adult patients still fail to reach normal stature. Furthermore, adult patients with XLH report comorbidities associated with unresolved childhood disease, as well as newly developed disease-related complications and significantly impaired quality of life (QOL). Despite the multiple negative aspects of XLH, Asian consensus statements for diagnosis and management are lacking. METHODS AND ANALYSIS The Study of longitUdinal observatioN For patients with X-Linked hypOphosphataemic rickets/osteomalacia in collaboration With Asian partnERs study is a longitudinal observational cohort study of patients with XLH, designed to determine the medical characteristics and burdens (physical, emotional and financial) of this progressive disease and to evaluate the impact of treatment (including the use of burosumab) on clinical outcomes. The study was initiated in April 2018, and registration will remain open until 30 April 2022. The sample size planned for analyses is 160 patients, consisting of 100 patients in Japan and 60 patients in Korea. Up to 5 years of observation are planned per patient, from enrolment through to April 2023. Prospective and retrospective data will be collected to evaluate variables, including height/growth, rickets severity score, QOL, motor function and biomarkers for phosphate metabolism and bone turnover. ETHICS AND DISSEMINATION Ethics approval was obtained from the Ethics Committee of Osaka University, the Ethics Committee of Kyowa Kirin Co and by the Ethics Committee of each participating medical institution. Two interim analyses and associated publications are planned using retrospective and enrolment data at year 1 and results at year 3. TRIAL REGISTRATION NUMBERS NCT03745521; UMIN000031605.
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Affiliation(s)
- Takuo Kubota
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Japan
| | - Seiji Fukumoto
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, Tokushima, Japan
| | - Hae Il Cheong
- Department of Pediatric Nephrology, Seoul National University Children's Hospital, Seoul, Republic of Korea
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Osaka Women's and Children's Hospital, Izumi, Japan
| | - Noriyuki Namba
- Department of Pediatrics and Perinatology, Faculty of Medicine, Tottori University, Tottori, Japan
| | - Nobuaki Ito
- Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo, Japan
| | - Shin Tokunaga
- Medical Affairs Department, Kyowa Kirin Co Ltd, Tokyo, Japan
| | - Yoshimi Gibbs
- Medical Affairs Department, Kyowa Kirin Co Ltd, Tokyo, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Suita, Japan
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Li B, Wang X, Hao X, Liu Y, Wang Y, Shan C, Ao X, Liu Y, Bao H, Li P. A novel c.2179T>C mutation blocked the intracellular transport of PHEX protein and caused X-linked hypophosphatemic rickets in a Chinese family. Mol Genet Genomic Med 2020; 8:e1262. [PMID: 32511895 PMCID: PMC7434742 DOI: 10.1002/mgg3.1262] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 03/23/2020] [Indexed: 12/13/2022] Open
Abstract
Background X‐linked hypophosphatemic rickets (XLH) is a heterogeneous genetic phosphate wasting disorder that occupies the majority of inheritable hypophosphatemic rickets (HR). XLH is caused by loss‐of‐function mutations in the phosphate‐regulating endopeptidase gene (PHEX) located on the X chromosome. Method In this study, we performed whole‐exome sequencing (WES) on the proband to identify the causative gene. The mutations were analyzed by predictive online software, such as PolyPhen‐2. Plasmids containing the wild‐type (WT) and mutant cDNA of the candidate gene were transfected into HEK293, then, the expression, cellular localization, and glycosylation state of the candidate proteins were detected by western blot, immunostaining, and endoglycosidase H digestion. The expression and concentration of related factor were measured by RT‐PCR and ELISA. Results We identified a novel missense mutation c.2179T>C in the PHEX that results in the substitution of p.Phe727Leu (F727L). This mutation was predicted to be disease‐causing by all four predictive online software. In vitro studies demonstrated that the F727L substitution hindered the intracellular trafficking of the mutant PHEX, with ~59% of mutant PHEX protein retained in the endoplasmic reticulum (ER) and only ~16% of the mutant protein localized on the cell surface. Endoglycosidase H digestion assay showed that the mutant F727L PHEX protein was not fully glycosylated. The concentration of intact FGF23 in hFOB1.19 cell culture medium collected from the mutant PHEX group was the highest (62.9 pg/ml) compared to the WT group (32.1 pg/ml) and control group (23.5 pg/ml). Conclusion Our results confirmed that the mutant PHEX protein was lowly glycosylated and retarded within the ER, the intact FGF23 level in cell culture media caused by the mutant PHEX protein was significantly elevated compared to that of the WT group, which may explain why the single base mutation in the PHEX led to XLH syndrome in this family.
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Affiliation(s)
- Baowei Li
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Xiong Wang
- Department of Reproductive Medicine, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Xiaodan Hao
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Yanran Liu
- School of Basic Medicine, Qingdao University, Qingdao, China
| | - Yin Wang
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Chan Shan
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Xiang Ao
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - Ying Liu
- Institute for Translational Medicine, Qingdao University, Qingdao, China
| | - HongChu Bao
- Department of Reproductive Medicine, Affiliated Yantai Yuhuangding Hospital of Qingdao University, Yantai, China
| | - Peifeng Li
- Institute for Translational Medicine, Qingdao University, Qingdao, China
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Rothenbuhler A, Schnabel D, Högler W, Linglart A. Diagnosis, treatment-monitoring and follow-up of children and adolescents with X-linked hypophosphatemia (XLH). Metabolism 2020; 103S:153892. [PMID: 30928313 DOI: 10.1016/j.metabol.2019.03.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 03/22/2019] [Accepted: 03/25/2019] [Indexed: 11/19/2022]
Abstract
Early diagnosis, optimal therapeutic management and regular follow up of children with X-linked hypophosphatemia (XLH) determine their long term outcomes and future quality of life. Biochemical screening of potentially affected newborns in familial cases and improving physician's knowledge on clinical signs, symptoms and biochemical characteristics of XLH for de novo cases should lead to earlier diagnosis and treatment initiation. The follow-up of children with XLH includes clinical, biochemical and radiological monitoring of treatment (efficacy and complications) and screening for XLH-related dental, neurosurgical, rheumatological, cardiovascular, renal and ENT complications. In 2018, the European Union approved the use of burosumab, a humanized monoclonal anti-FGF23 antibody, as an alternative therapy to conventional therapy (active vitamin D analogues and phosphate supplements) in growing children with XLH and insufficiently controlled disease. Diagnostic criteria of XLH and the principles of disease management with conventional treatment or with burosumab are reviewed in this paper.
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Affiliation(s)
- Anya Rothenbuhler
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Sud 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-Sud, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France.
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charité, University Medicine Berlin, Germany
| | - Wolfgang Högler
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham, United Kingdom; Department of Pediatrics and Adolescent Medicine, Johannes Kepler University Linz, Linz, Austria
| | - Agnès Linglart
- APHP, Endocrinology and Diabetology for Children, Bicêtre Paris Sud 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-Sud, Bicêtre Paris Sud Hospital, Le Kremlin-Bicêtre, France
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X-linked Hypophosphatemic Rickets: the Challenges of Treatment. Clin Rev Bone Miner Metab 2019. [DOI: 10.1007/s12018-019-09266-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Haffner D, Emma F, Eastwood DM, Duplan MB, Bacchetta J, Schnabel D, Wicart P, Bockenhauer D, Santos F, Levtchenko E, Harvengt P, Kirchhoff M, Di Rocco F, Chaussain C, Brandi ML, Savendahl L, Briot K, Kamenicky P, Rejnmark L, Linglart A. Clinical practice recommendations for the diagnosis and management of X-linked hypophosphataemia. Nat Rev Nephrol 2019; 15:435-455. [PMID: 31068690 PMCID: PMC7136170 DOI: 10.1038/s41581-019-0152-5] [Citation(s) in RCA: 271] [Impact Index Per Article: 54.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
X-linked hypophosphataemia (XLH) is the most common cause of inherited phosphate wasting and is associated with severe complications such as rickets, lower limb deformities, pain, poor mineralization of the teeth and disproportionate short stature in children as well as hyperparathyroidism, osteomalacia, enthesopathies, osteoarthritis and pseudofractures in adults. The characteristics and severity of XLH vary between patients. Because of its rarity, the diagnosis and specific treatment of XLH are frequently delayed, which has a detrimental effect on patient outcomes. In this Evidence-Based Guideline, we recommend that the diagnosis of XLH is based on signs of rickets and/or osteomalacia in association with hypophosphataemia and renal phosphate wasting in the absence of vitamin D or calcium deficiency. Whenever possible, the diagnosis should be confirmed by molecular genetic analysis or measurement of levels of fibroblast growth factor 23 (FGF23) before treatment. Owing to the multisystemic nature of the disease, patients should be seen regularly by multidisciplinary teams organized by a metabolic bone disease expert. In this article, we summarize the current evidence and provide recommendations on features of the disease, including new treatment modalities, to improve knowledge and provide guidance for diagnosis and multidisciplinary care.
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Affiliation(s)
- Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany.
- Center for Congenital Kidney Diseases, Center for Rare Diseases, Hannover Medical School, Hannover, Germany.
| | - Francesco Emma
- Department of Pediatric Subspecialties, Division of Nephrology, Children's Hospital Bambino Gesù - IRCCS, Rome, Italy
| | - Deborah M Eastwood
- Department of Orthopaedics, Great Ormond St Hospital for Children, Orthopaedics, London, UK
- The Catterall Unit Royal National Orthopaedic Hospital NHS Trust, Stanmore, UK
| | - Martin Biosse Duplan
- Dental School, Université Paris Descartes Sorbonne Paris Cité, Montrouge, France
- APHP, Department of Odontology, Bretonneau Hospital, Paris, France
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
| | - Justine Bacchetta
- Department of Pediatric Nephrology, Rheumatology and Dermatology, University Children's Hospital, Lyon, France
| | - Dirk Schnabel
- Center for Chronic Sick Children, Pediatric Endocrinology, Charitè, University Medicine, Berlin, Germany
| | - Philippe Wicart
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
- APHP, Department of Pediatric Orthopedic Surgery, Necker - Enfants Malades University Hospital, Paris, France
- Paris Descartes University, Paris, France
| | - Detlef Bockenhauer
- University College London, Centre for Nephrology and Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Fernando Santos
- Hospital Universitario Central de Asturias (HUCA), University of Oviedo, Oviedo, Spain
| | - Elena Levtchenko
- Department of Pediatric Nephrology and Development and Regeneration, University Hospitals Leuven, University of Leuven, Leuven, Belgium
| | - Pol Harvengt
- RVRH-XLH, French Patient Association for XLH, Suresnes, France
| | - Martha Kirchhoff
- Phosphatdiabetes e.V., German Patient Association for XLH, Lippstadt, Germany
| | - Federico Di Rocco
- Pediatric Neurosurgery, Hôpital Femme Mère Enfant, Centre de Référence Craniosténoses, Université de Lyon, Lyon, France
| | - Catherine Chaussain
- Dental School, Université Paris Descartes Sorbonne Paris Cité, Montrouge, France
- APHP, Department of Odontology, Bretonneau Hospital, Paris, France
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
| | - Maria Louisa Brandi
- Metabolic Bone Diseases Unit, Department of Surgery and Translational Medicine, University of Florence, Florence, Italy
| | - Lars Savendahl
- Pediatric Endocrinology Unit, Karolinska University Hospital, Department of Women's and Children's Health, Karolinska Institutet, Stockholm, Sweden
| | - Karine Briot
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
- Paris Descartes University, Paris, France
- APHP, Department of Rheumatology, Cochin Hospital, Paris, France
- INSERM UMR-1153, Paris, France
| | - Peter Kamenicky
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
- APHP, Department of Endocrinology and Reproductive Diseases, Bicêtre Paris-Sud Hospital, Paris, France
- INSERM U1185, Bicêtre Paris-Sud, Paris-Sud - Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Lars Rejnmark
- Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark
| | - Agnès Linglart
- APHP, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, and Filière OSCAR, Paris, France
- INSERM U1185, Bicêtre Paris-Sud, Paris-Sud - Paris Saclay University, Le Kremlin-Bicêtre, France
- APHP, Platform of Expertise of Paris-Sud for Rare Diseases and Filière OSCAR, Bicêtre Paris-Sud Hospital (HUPS), Le Kremlin-Bicêtre, France
- APHP, Endocrinology and Diabetes for Children, Bicêtre Paris-Sud Hospital, Le Kremlin-Bicêtre, France
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Chesher D, Oddy M, Darbar U, Sayal P, Casey A, Ryan A, Sechi A, Simister C, Waters A, Wedatilake Y, Lachmann RH, Murphy E. Outcome of adult patients with X-linked hypophosphatemia caused by PHEX gene mutations. J Inherit Metab Dis 2018; 41:865-876. [PMID: 29460029 PMCID: PMC6133187 DOI: 10.1007/s10545-018-0147-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 01/07/2018] [Accepted: 01/24/2018] [Indexed: 01/09/2023]
Abstract
X-linked hypophosphatemia (XLH) is the most common monogenic disorder causing hypophosphatemia. This case-note review documents the clinical features and the complications of treatment in 59 adults (19 male, 40 female) with XLH. XLH is associated with a large number of private mutations; 37 different mutations in the PHEX gene were identified in this cohort, 14 of which have not been previously reported. Orthopaedic involvement requiring surgical intervention (osteotomy) was frequent. Joint replacement and decompressive laminectomy were observed in those older than 40 years. Dental disease (63%), nephrocalcinosis (42%), and hearing impairment (14%) were also common. The rarity of the disease and the large number of variants make it difficult to discern specific genotype-phenotype relationships. A new treatment, an anti-FGF23 antibody, that may affect the natural history of the disease is currently being investigated in clinical trials.
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Affiliation(s)
- Douglas Chesher
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- New South Wales Health Pathology, Royal North Shore Hospital, St Leonards, NSW, Australia
| | - Michael Oddy
- Department of Trauma and Orthopaedics, University College London Hospitals NHS Foundation Trust, London, UK
| | - Ulpee Darbar
- Department of Periodontology, Eastman Dental Hospital, London, UK
| | - Parag Sayal
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Adrian Casey
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
| | - Aidan Ryan
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Chemical Pathology and Metabolic Medicine, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Annalisa Sechi
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Centre for Rare Disease, Academic Hospital of Udine, Udine, Italy
| | - Charlotte Simister
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Aoife Waters
- Institute of Child Health, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK
| | - Yehani Wedatilake
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
- Imperial College London NHS Foundation Trust, London, UK
| | - Robin H Lachmann
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK
| | - Elaine Murphy
- Charles Dent Metabolic Unit, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG, UK.
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Gao Y, Wang ZM, Li XL. Analysis of 2 novel mutations of PHEX gene inducing X-linked dominant hypophosphatemia rickets in 2 families: Two case reports. Medicine (Baltimore) 2018; 97:e11453. [PMID: 30075510 PMCID: PMC6081144 DOI: 10.1097/md.0000000000011453] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
RATIONALE X-linked dominant hypophosphatemia rickets (XLH, OMIM 307800) is the most common hereditary hypophosphatemic rickets and characterized by growth retardation, skeletal malformations, dental dysplasia, spontaneous fractures and osteomalacia. PHEX gene was identified for XLH and novel mutations were consistent with loss of function. PATIENT CONCERNS Case1: the proband 1 III3 in family 1 was a fourteen-year-old boy with bowing of bilateral legs, obviously enlarged joints, tooth absence and difficulty in walking; X-rays showed bilateral femoral multiple fractures with sclerosis at the fracture edge. Case 2: the proband 2 III2, a five-year-old boy in family 2, showed growth retardation, dental dysplasia, gingiva abscess and bilateral legs malformations; X-rays showed low bone density, delayed bone age, bowing of legs, frayed and widened metaphyses of the distal femurs and proximal tibias. Both of their mothers suffered from skeletal malformations, tooth absence and were performed with osteotomy due to fractures of lower limb. Their biochemical parameters showed hypophosphatemia, elevated alkaline phosphatase. DIAGNOSES X-linked dominant hypophosphatemia rickets (XLH). INTERVENTIONS AND OUTCOMES Treatment with high doses of phosphate and 1,25-dihydroxyvitamin D3, the height of proband 2 increased 10 cm and femoral Multiple fracture of proband1 almost healed after treatment for 6 months and the patients's PHEX gene was investigated. LESSONS Two novel pathogenic PHEX mutations were found: c.497delG in family 1 and c.388G> T in family 2, both of which caused early termination of translation and produced truncated protein. Serum FGF23 concentration in our XLH patients were obviously higher than the normal and may be related to age to some extent. Early initiation of treatment produces better effect.
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Meyerhoff N, Haffner D, Staude H, Wühl E, Marx M, Beetz R, Querfeld U, Holder M, Billing H, Rabl W, Schröder C, Hiort O, Brämswig JH, Richter-Unruh A, Schnabel D, Živičnjak M. Effects of growth hormone treatment on adult height in severely short children with X-linked hypophosphatemic rickets. Pediatr Nephrol 2018; 33:447-456. [PMID: 29058153 DOI: 10.1007/s00467-017-3820-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 08/30/2017] [Accepted: 09/17/2017] [Indexed: 12/11/2022]
Abstract
BACKGROUND We recently showed that a 3-year growth hormone (GH) treatment improves linear growth in severely short children with X-linked hypophosphatemic rickets (XLH). It is unknown if GH therapy increases adult height in XLH patients. METHODS We carried out a follow-up analysis of a randomized controlled open-label GH study in short prepubertal children with XLH on phosphate and active vitamin D treatment. The changes in SD scores (SDS) of height, sitting height, leg and arm length, and sitting height index (i.e., the ratio between sitting height and height) were analyzed in 11 out of 16 patients followed-up until adult height. RESULTS At baseline, XLH patients showed disproportionately short stature with reduced standardized height (-3.2 ± 0.6), sitting height (-1.7 ± 0.6), leg (-3.7 ± 0.7) and arm (-2.5 ± 0.8) length, and markedly elevated sitting height index (3.3 ± 0.6; each p < 0.01 versus healthy children). In GH-treated patients, adult height, sitting height, leg length, and arm length exceeded baseline values by 0.7 SDS, 1.7 SDS, 0.7 SDS, and 1.2 SDS respectively, although this was only significant for sitting height. In controls, no significant changes in linear body dimensions were noted. Adult height did not statistically differ between groups (-2.4 ± 0.7 vs -3.3 ± 1.2, p = 0.082). GH did not exaggerate body disproportion. CONCLUSIONS Growth hormone treatment did not significantly increase adult height in this group of short children with XLH, which may be at least partly due to the small number of patients included in our study.
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Affiliation(s)
- Nadine Meyerhoff
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - Dieter Haffner
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany
| | - Hagen Staude
- University Children's Hospital Rostock, Rostock, Germany
| | - Elke Wühl
- University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Michaela Marx
- University Children's Hospital Erlangen, Erlangen, Germany
| | - Rolf Beetz
- University Children's Hospital Mainz, Mainz, Germany
| | - Uwe Querfeld
- Department of Pediatric Nephrology, University Children's Hospital, Charité, Berlin, Germany
| | - Martin Holder
- Department of Pediatrics, Klinikum Stuttgart, Olgahospital, Stuttgart, Germany
| | - Heiko Billing
- University Children's Hospital Tübingen, Tübingen, Germany
| | - Wolfgang Rabl
- Children's Hospital of the Technical University Munich, Munich, Germany
| | - Carmen Schröder
- University Children's Hospital Greifswald, Greifswald, Germany
| | - Olaf Hiort
- Division of Pediatric Endocrinology and Diabetes, Department of Pediatrics and Adolescent Medicine, University of Lübeck, Lübeck, Germany
| | | | | | - Dirk Schnabel
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Center for Chronically Sick Children, Pediatric Endocrinology, Berlin, Germany
| | - Miroslav Živičnjak
- Department of Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany.
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Abstract
Inborn errors of metabolism encompass a wide spectrum of disorders, frequently affecting bone. The most important metabolic disorders that primarily influence calcium or phosphate balance, resulting in skeletal pathology, are hypophosphatemic rickets and hypophosphatasia. Conditions involving bone marrow or affecting skeletal growth and development are mainly the lysosomal storage disorders, in particular the mucopolysaccharidoses. In these disorders skeletal abnormalities are often the presenting symptom and early recognition and intervention improves outcome in many of these diseases. Many disorders of intermediary metabolism may impact bone health as well, resulting in higher frequencies of osteopenia and osteoporosis. In these conditions factors contributing to the reduced bone mineralization can be the disorder itself, the strict dietary treatment, reduced physical activity or sunlight exposure and/or early ovarian failure. Awareness of these primary or secondary bone problems amongst physicians treating patients with inborn errors of metabolism is of importance for optimization bone health and recognition of skeletal complications.
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Affiliation(s)
- M Langeveld
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
| | - C E M Hollak
- Department of Endocrinology and Metabolism, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands
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Abstract
Rickets is a metabolic bone disease that develops as a result of inadequate mineralization of growing bone due to disruption of calcium, phosphorus and/or vitamin D metabolism. Nutritional rickets remains a significant child health problem in developing countries. In addition, several rare genetic causes of rickets have also been described, which can be divided into two groups. The first group consists of genetic disorders of vitamin D biosynthesis and action, such as vitamin D-dependent rickets type 1A (VDDR1A), vitamin D-dependent rickets type 1B (VDDR1B), vitamin D-dependent rickets type 2A (VDDR2A), and vitamin D-dependent rickets type 2B (VDDR2B). The second group involves genetic disorders of excessive renal phosphate loss (hereditary hypophosphatemic rickets) due to impairment in renal tubular phosphate reabsorption as a result of FGF23-related or FGF23-independent causes. In this review, we focus on clinical, laboratory and genetic characteristics of various types of hereditary rickets as well as differential diagnosis and treatment approaches.
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Affiliation(s)
- Sezer Acar
- Dokuz Eylül University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey
| | - Korcan Demir
- Dokuz Eylül University Faculty of Medicine, Department of Pediatric Endocrinology, İzmir, Turkey
| | - Yufei Shi
- King Faisal Specialist Hospital & Research Centre, Department of Genetics, Riyadh, Saudi Arabia
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Gizard A, Rothenbuhler A, Pejin Z, Finidori G, Glorion C, de Billy B, Linglart A, Wicart P. Outcomes of orthopedic surgery in a cohort of 49 patients with X-linked hypophosphatemic rickets (XLHR). Endocr Connect 2017; 6:566-573. [PMID: 28954742 PMCID: PMC5633063 DOI: 10.1530/ec-17-0154] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 09/07/2017] [Indexed: 01/18/2023]
Abstract
BACKGROUND X-linked hypophosphatemic rickets (XLHR) is due to mutations in PHEX leading to unregulated production of FGF23 and hypophosphatemia. XLHR is characterized by leg bowing of variable severity. Phosphate supplements and oral vitamin analogs, partially or, in some cases, fully restore the limb straightness. Surgery is the alternative for severe or residual limb deformities. OBJECTIVE To retrospectively assess the results of surgical limb correction in XLHR (osteotomies and bone alignment except for 3 transient hemiepiphysiodesis). METHODS We analyzed the incidence of recurrence and post-surgical complications in 49 XLHR patients (29F, 20M) (mean age at diagnosis 6.0 years (± 7.1)). RESULTS At first surgery, the mean age was 13.4 years (± 5.0). Recurrence was observed in 14/49 (29%) patients. The number of additional operations significantly decreased with age (2.0 (± 0.9), 1.7 (± 1.0) and 1.2 (± 0.4) in children <11 years, between 11 and 15, and >15 years; P < 0.001). Incidence of recurrence seemed to be lower in patients with good metabolic control of the rickets (25% vs 33%). Complications were observed in 57% of patients. CONCLUSION We report a large series of surgical procedures in XLHR. Our results confirm that phosphate supplements and vitamin D analog therapy is the first line of treatment to correct leg bowing. Surgery before puberty is associated with a high risk of recurrence of the limb deformity. Such procedures should only be recommended, following multidisciplinary discussions, in patients with severe distortion leading to mechanical joint and ligament complications, or for residual deformities once growth plates have fused.
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Affiliation(s)
- A Gizard
- Department of Pediatric Orthopedic SurgeryBesançon University Hospital, Paris, France
| | - A Rothenbuhler
- APHPDepartment of Pediatric Endocrinology, Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- Reference Center for Rare Disorders of Calcium and Phosphate MetabolismLe Kremlin Bicêtre, France
- Plateforme d'Expertise Paris Sud Maladies Rares and Filière OSCARBicêtre Paris Sud, Le Kremlin Bicêtre, France
| | - Z Pejin
- APHPDepartment of Pediatric Orthopedic Surgery, Necker Hospital, Paris, France
| | - G Finidori
- APHPDepartment of Pediatric Orthopedic Surgery, Necker Hospital, Paris, France
| | - C Glorion
- APHPDepartment of Pediatric Orthopedic Surgery, Necker Hospital, Paris, France
| | - B de Billy
- Department of Pediatric Orthopedic SurgeryBesançon University Hospital, Paris, France
| | - A Linglart
- APHPDepartment of Pediatric Endocrinology, Bicêtre Paris Sud, Le Kremlin Bicêtre, France
- Reference Center for Rare Disorders of Calcium and Phosphate MetabolismLe Kremlin Bicêtre, France
- Plateforme d'Expertise Paris Sud Maladies Rares and Filière OSCARBicêtre Paris Sud, Le Kremlin Bicêtre, France
- INSERM U1169Hôpital Bicêtre, Le Kremlin Bicêtre, et Université Paris-Saclay, Le Kremlin Bicêtre, France
| | - P Wicart
- Reference Center for Rare Disorders of Calcium and Phosphate MetabolismLe Kremlin Bicêtre, France
- APHPDepartment of Pediatric Orthopedic Surgery, Necker Hospital, Paris, France
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39
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Horn A, Wright J, Bockenhauer D, Van’t Hoff W, Eastwood DM. The orthopaedic management of lower limb deformity in hypophosphataemic rickets. J Child Orthop 2017; 11:298-305. [PMID: 28904636 PMCID: PMC5584499 DOI: 10.1302/1863-2548.11.170003] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Many patients with X-linked hypophosphataemic rickets (X-LHPR) demonstrate significant lower limb deformity despite optimal medical management. This study evaluates the use of guided growth by means of hemi-epiphysiodesis to address coronal plane deformity in the skeletally immature child. METHODS Since 2005, 24 patients with X-LHPR have been referred to our orthopaedic unit for evaluation. All patients had standardised long leg radiographs that were analysed sequentially before and after surgery if any was performed. The rate of correction of deformity was calculated based on peri-articular angles and diaphyseal deformity angles measured at regular intervals using Traumacad software. Clinical records were reviewed to obtain relevant clinical and demographic details. Statistical analysis was performed using SPSS 23 (SPSS Inc., Chicago, IL, USA). RESULTS The indication for surgical intervention was a mechanical axis progressing through Zone 2 or in Zone 3 despite one year of optimised medical treatment. The 15 patients underwent 16 episodes of guided growth (30 limbs, 38 segments) at a mean age of 10.3 years. In four limbs, surgery has only taken place recently; and in three limbs, correction is ongoing. Neutral mechanical axis was restored in 16/23 (70%) limbs: six improved and one limb (one segment) required osteotomy for residual deformity. The mean rate of angular correction per month was 0.3° for the proximal tibia and 0.7° for the distal femur. Patients with ≥ 3 years of growth remaining responded significantly better than older patients (p = 0.004). Guided growth was more successful in correcting valgus than varus deformity (p = 0.007). In younger patients, diaphyseal deformity corrected at a rate of 0.2° and 0.6° per month for the tibia and the femur, respectively. There has been one case of recurrent deformity. Patients with corrected coronal plane alignment did not complain of significant residual torsional malalignment. Serum phosphate and alkaline phosphatase levels did not affect response to surgery. CONCLUSIONS Guided growth is a successful, minimally invasive method of addressing coronal plane deformity in X-LHPR. If coronal plane deformity is corrected early in patients with good metabolic control, osteotomy can be avoided.
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Affiliation(s)
- A. Horn
- Department of Orthopaedic Surgery, Red Cross War Memorial Hospital for Children, Cape Town, South Africa,aCorrespondence should be sent to: Anria Horn, Department of Orthopaedic Surgery, University of Cape Town. Room H49, Old Main Building, Groote Schuur Hospital, Anzio Road, Observatory, Cape Town, South Africa. E-mail:
| | - J. Wright
- Department of Orthopaedic Surgery, Great Ormond St Hospital for Children, LondonUK
| | - D. Bockenhauer
- Department of Nephro-Urology, Great Ormond St Hospital for Children, LondonUK
| | - W. Van’t Hoff
- Department of Nephro-Urology, Great Ormond St Hospital for Children, LondonUK
| | - D. M. Eastwood
- Department of Orthopaedic Surgery, Great Ormond St Hospital for Children, LondonUK
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Abstract
Fibroblast growth factor 23 (FGF23) is an important regulator of phosphate and vitamin D metabolism and its excessive or insufficient production leads to a wide variety of skeletal disorders. This article reviews the FGF23-α-Klotho signaling pathway, highlighting the latest developments in FGF23 regulation and action, and describes the disorders associated with FGF23 excess or deficiency.
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Affiliation(s)
- Anda R Gonciulea
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Suzanne M Jan De Beur
- Division of Endocrinology, Diabetes and Metabolism, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Rafaelsen S, Johansson S, Ræder H, Bjerknes R. Hereditary hypophosphatemia in Norway: a retrospective population-based study of genotypes, phenotypes, and treatment complications. Eur J Endocrinol 2016; 174:125-36. [PMID: 26543054 PMCID: PMC4674593 DOI: 10.1530/eje-15-0515] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 11/04/2015] [Indexed: 01/14/2023]
Abstract
OBJECTIVE Hereditary hypophosphatemias (HH) are rare monogenic conditions characterized by decreased renal tubular phosphate reabsorption. The aim of this study was to explore the prevalence, genotypes, phenotypic spectrum, treatment response, and complications of treatment in the Norwegian population of children with HH. DESIGN Retrospective national cohort study. METHODS Sanger sequencing and multiplex ligand-dependent probe amplification analysis of PHEX and Sanger sequencing of FGF23, DMP1, ENPP1KL, and FAM20C were performed to assess genotype in patients with HH with or without rickets in all pediatric hospital departments across Norway. Patients with hypercalcuria were screened for SLC34A3 mutations. In one family, exome sequencing was performed. Information from the patients' medical records was collected for the evaluation of phenotype. RESULTS Twety-eight patients with HH (18 females and ten males) from 19 different families were identified. X-linked dominant hypophosphatemic rickets (XLHR) was confirmed in 21 children from 13 families. The total number of inhabitants in Norway aged 18 or below by 1st January 2010 was 1,109,156, giving an XLHR prevalence of ∼1 in 60,000 Norwegian children. FAM20C mutations were found in two brothers and SLC34A3 mutations in one patient. In XLHR, growth was compromised in spite of treatment with oral phosphate and active vitamin D compounds, with males tending to be more affected than females. Nephrocalcinosis tended to be slightly more common in patients starting treatment before 1 year of age, and was associated with higher average treatment doses of phosphate. However, none of these differences reached statistical significance. CONCLUSIONS We present the first national cohort of HH in children. The prevalence of XLHR seems to be lower in Norwegian children than reported earlier.
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Affiliation(s)
- Silje Rafaelsen
- Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway
| | - Stefan Johansson
- Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway
| | - Helge Ræder
- Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway
| | - Robert Bjerknes
- Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway Section for PediatricsDepartment of Clinical Science, Haukeland University Hospital, University of Bergen, N-5021 Bergen, NorwayCenter for Medical Genetics and Molecular MedicineDepartment of PediatricsHaukeland University Hospital, Bergen, Norway
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Zou J, Xiong X, Lai B, Sun M, Tu X, Gao X. Glucose metabolic abnormality is associated with defective mineral homeostasis in skeletal disorder mouse model. SCIENCE CHINA-LIFE SCIENCES 2015; 58:359-67. [DOI: 10.1007/s11427-015-4827-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 12/31/2014] [Indexed: 12/17/2022]
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Khosravi M, Walsh SB. The long-term complications of the inherited tubulopathies: an adult perspective. Pediatr Nephrol 2015; 30:385-95. [PMID: 24566812 DOI: 10.1007/s00467-014-2779-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 11/25/2022]
Abstract
The inherited tubulopathies are lifelong disorders and their clinical features and complications may present quite different challenges in adulthood from those in childhood. In this review we outline the pathophysiology and documented complications (including the late and unusual) of the monogenic tubulopathies from the perspective of the adult nephrologist.
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Affiliation(s)
- Maryam Khosravi
- UCL Centre for Nephrology, Royal Free Hospital, University College London, London, UK
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44
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Pekkarinen T, Lorenz-Depiereux B, Lohman M, Mäkitie O. Unusually severe hypophosphatemic rickets caused by a novel and complex re-arrangement of thePHEXgene. Am J Med Genet A 2014; 164A:2931-7. [DOI: 10.1002/ajmg.a.36721] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 07/09/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Tuula Pekkarinen
- Division of Endocrinology; Department of Medicine; Helsinki University Central Hospital; Vantaa Finland
| | | | - Martina Lohman
- HUS Medical Imaging Center; Helsinki University Hospital; Helsinki Finland
| | - Outi Mäkitie
- Pediatric Endocrinology and Metabolic Bone Diseases; Children's Hospital; Helsinki University Central Hospital and University of Helsinki; Helsinki Finland
- Folkhälsan Institute of Genetics; Helsinki Finland
- Department of Molecular Medicine and Surgery; Karolinska Institutet; and Department of Clinical Genetics; Karolinska University Hospital; Stockholm Sweden
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Yue H, Yu JB, He JW, Zhang Z, Fu WZ, Zhang H, Wang C, Hu WW, Gu JM, Hu YQ, Li M, Liu YJ, Zhang ZL. Identification of two novel mutations in the PHEX gene in Chinese patients with hypophosphatemic rickets/osteomalacia. PLoS One 2014; 9:e97830. [PMID: 24836714 PMCID: PMC4024000 DOI: 10.1371/journal.pone.0097830] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 04/25/2014] [Indexed: 11/25/2022] Open
Abstract
Objective X-linked dominant hypophosphatemia (XLH) is the most prevalent form of inherited rickets/osteomalacia in humans. The aim of this study was to identify PHEX gene mutations and describe the clinical features observed in 6 unrelated Chinese families and 3 sporadic patients with hypophosphatemic rickets/osteomalacia. Methods For this study, 45 individuals from 9 unrelated families of Chinese Han ethnicity (including 16 patients and 29 normal phenotype subjects), and 250 healthy donors were recruited. All 22 exons and exon-intron boundaries of the PHEX gene were amplified by polymerase chain reaction (PCR) and directly sequenced. Results The PHEX mutations were detected in 6 familial and 3 sporadic hypophosphatemic rickets/osteomalacia. Altogether, 2 novel mutations were detected: 1 missense mutation c.1183G>C in exon 11, resulting in p.Gly395Arg and 1 missense mutation c.1751A>C in exon 17, resulting in p.His584Pro. No mutations were found in the 250 healthy controls. Conclusions Our study increases knowledge of the PHEX gene mutation types and clinical phenotypes found in Chinese patients with XLH, which is important for understanding the genetic basis of XLH. The molecular diagnosis of a PHEX genetic mutation is of great importance for confirming the clinical diagnosis of XLH, conducting genetic counseling, and facilitating prenatal intervention, especially in the case of sporadic patients.
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Affiliation(s)
- Hua Yue
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Jin-bo Yu
- Department of pediatrics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Jin-wei He
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Zeng Zhang
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
- Department of Orthopedic Surgery, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P.R. China
| | - Wen-zhen Fu
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Hao Zhang
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Chun Wang
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Wei-wei Hu
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Jie-mei Gu
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Yun-qiu Hu
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Miao Li
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Yu-juan Liu
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
| | - Zhen-Lin Zhang
- Department of Osteoporosis, Metabolic Bone Disease and Genetic Research Unit, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai, P. R. China
- * E-mail:
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46
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Cheon CK, Lee HS, Kim SY, Kwak MJ, Kim GH, Yoo HW. A novel de novo mutation within PHEX gene in a young girl with hypophosphatemic rickets and review of literature. Ann Pediatr Endocrinol Metab 2014; 19:36-41. [PMID: 24926462 PMCID: PMC4049552 DOI: 10.6065/apem.2014.19.1.36] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/23/2013] [Accepted: 10/26/2013] [Indexed: 01/30/2023] Open
Abstract
X-linked hypophosphatemia (XLH) is the most common form of familial hypophosphatemic rickets and it is caused by loss-of-function mutations in the PHEX gene. Recently, a wide variety of PHEX gene defects in XLH have been revealed; these include missense mutations, nonsense mutations, splice site mutations, insertions, and deletions. Recently, we encountered a 2-year-9-month-old female with sporadic hypophosphatemic rickets. She underwent osteotomy, dental abscess was evident, and there was severe bowing of the legs. A low serum phosphorus level in combination with elevated serum alkaline phosphatase activity and normal serum calcium is suggestive of hypophosphatemic rickets. PHEX gene analysis revealed a splice acceptor site mutation, c.934-1G>T (IVS8(-1)G>T), at the intron8 and exon9 junction. To the best of our knowledge, this mutation is novel and has not been reported. The results of this study expand and improve our understanding of the clinical and molecular characteristics and the global pool of patients with sporadic hypophosphatemic rickets.
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Affiliation(s)
- Chong Kun Cheon
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
| | - Hoon Sang Lee
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
| | - Su Yung Kim
- Department of Pediatrics, Pusan National University Children's Hospital, Pusan National University School of Medicine, Yangsan, Korea
| | - Min Jung Kwak
- Department of Pediatrics, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea
| | - Gu-Hwan Kim
- Medical Genetics Clinic and Laboratory, Asan Medical Center Children's Hospital, Seoul, Korea
| | - Han-Wook Yoo
- Medical Genetics Clinic and Laboratory, Asan Medical Center Children's Hospital, Seoul, Korea
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47
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Penido MGMG, Alon US. Hypophosphatemic rickets due to perturbations in renal tubular function. Pediatr Nephrol 2014; 29:361-73. [PMID: 23636577 DOI: 10.1007/s00467-013-2466-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 03/03/2013] [Accepted: 03/04/2013] [Indexed: 12/13/2022]
Abstract
The common denominator for all types of rickets is hypophosphatemia, leading to inadequate supply of the mineral to the growing bone. Hypophosphatemia can result from insufficient uptake of the mineral from the gut or its disproportionate losses in the kidney, the latter being caused by either tubular abnormalities per se or the effect on the tubule of circulating factors like fibroblast growth factor-23 and parathyroid hormone (PTH). High serum levels of the latter result in most cases from abnormalities in vitamin D metabolism which lead to decreased calcium absorption in the gut and hypocalcemia, triggering PTH secretion. Rickets is a disorder of the growth plate and hence pediatric by definition. However, it is important to recognize that the effect of hypophosphatemia on other parts of the skeleton results in osteomalacia in both children and adults. This review addresses the etiology, pathophysiologic mechanisms, clinical manifestations and treatment of entities associated with hypophosphatemic rickets due to perturbations in renal tubular function.
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Affiliation(s)
- Maria Goretti M G Penido
- Pediatric Nephrology Unit, Clinics Hospital, School of Medicine, Federal University of Minas Gerais, Av. Professor Alfredo Balena, 190, CEP, 30130100, Belo Horizonte, MG, Brazil,
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48
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Huang X, Jiang Y, Xia W. FGF23 and Phosphate Wasting Disorders. Bone Res 2013; 1:120-32. [PMID: 26273497 DOI: 10.4248/br201302002] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/25/2013] [Indexed: 11/10/2022] Open
Abstract
A decade ago, only two hormones, parathyroid hormone and 1,25(OH)2D, were widely recognized to directly affect phosphate homeostasis. Since the discovery of fibroblast growth factor 23 (FGF23) in 2000 (1), our understanding of the mechanisms of phosphate homeostasis and of bone mineralization has grown exponentially. FGF23 is the link between intestine, bone, and kidney together in phosphate regulation. However, we still do not know the complex mechanism of phosphate homeostasis and bone mineralization. The physiological role of FGF23 is to regulate serum phosphate. Secreted mainly by osteocytes and osteoblasts in the skeleton (2,3), it modulates kidney handling of phosphate reabsorption and calcitriol production. Genetic and acquired abnormalities in FGF23 structure and metabolism cause conditions of either hyper-FGF23 or hypo-FGF23. Hyper-FGF23 is related to hypophosphatemia, while hypo-FGF23 is related to hyperphosphatemia. Both hyper-FGF23 and hypo-FGF23 are detrimental to humans. In this review, we will discuss the pathophysiology of FGF23 and hyper-FGF23 related renal phosphate wasting disorders (4).
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Affiliation(s)
- Xianglan Huang
- Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences , Shuaifuyuan No. 1, Wangfujing, Dongcheng District, Beijing 100730, China
| | - Yan Jiang
- Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences , Shuaifuyuan No. 1, Wangfujing, Dongcheng District, Beijing 100730, China
| | - Weibo Xia
- Department of Endocrinology, Key Laboratory of Endocrinology, Ministry of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences , Shuaifuyuan No. 1, Wangfujing, Dongcheng District, Beijing 100730, China
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Abstract
Over the last decade the discovery of fibroblast growth factor 23 (FGF23) and the progressive and ongoing clarification of its role in phosphate and mineral metabolism have led to expansion of the diagnostic spectrum of primary hypophosphatemic syndromes. This article focuses on the impairment of growth in these syndromes. Growth retardation is a common, but not constant, feature and it presents with large variability. As a result of the very low prevalence of other forms of primary hypophosphatemic syndromes, the description of longitudinal growth and the pathogenesis of its impairment have been mostly studied in X-linked hypophosphatemia (XLH) patients and in Hyp mice, the animal model of this disease. In general, children with XLH have short stature with greater shortness of lower limbs than trunk. Treatment with phosphate supplements and 1α vitamin D derivatives heals active lesions of rickets, but does not normalize growth of XLH patients. Patients might benefit from recombinant human growth hormone (rhGH) therapy, which may accelerate the growth rate without increasing body disproportion or correcting hypophosphatemia. These clinical data as well as research findings obtained in Hyp mice suggest that the pathogenesis of defective growth in XLH and other hypophosphatemic syndromes is not entirely dependent on the mineralization disorder and point to other effects of hypophosphatemia itself or FGF23 on the metabolism of bone and growth plate.
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Affiliation(s)
- Fernando Santos
- Hospital Universitario Central de Asturias & University of Oviedo, Oviedo, Asturias, Spain.
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Fujiwara M, Namba N, Ozono K, Arisaka O, Yokoya S. Treatment of Hypophosphatemic Rickets with Phosphate and Active Vitamin D in Japan: A Questionnaire-based Survey. Clin Pediatr Endocrinol 2013. [PMID: 23966755 PMCID: PMC3748281 DOI: 10.1297/cpe.22.9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Hereditary hypophosphatemic rickets represented
by X-linked hypophosphatemic rickets (XLH) is a rare disorder characterized by
hypophosphatemia, elevated alkaline phosphatase (ALP) and undermineralization of bone.
Active vitamin D and phosphate are administered to correct hypophosphatemia and elevation
of ALP. Overtreatment with phosphate leads to secondary hyperparathyroidism, and a large
dose of active vitamin D has a risk of hypercalciuria. To understand the situation
concerning treatment of patients with hereditary hypophosphatemic rickets in Japan, we
conducted a questionnaire survey of pediatric endocrinologists. Answers were obtained from
53 out of 68 hospitals where the pediatric endocrinologists worked. One hundred and
thirty-five patients were treated in 28 hospitals during November 2009 and May 2010; 126
patients suffered from hereditary hypophosphatemic rickets, and 9 had hypophosphatemia
caused by other miscellaneous reasons. The distribution of patient age was as follows: 27
(21%) were between 6 mo and 6 yr of age, 39 (31%) were between 6 and 12 yr of age, and 60
(48%) were more than 12 yr of age. Active vitamin D was given to 123 patients, and
phosphate was given to 106 patients. As for the dose of phosphorus, 37.2–58.1 mg/kg/d was
given divided into 2 to 6 aliquots. There were various control targets of treatment,
including serum phosphate, serum ALP, rachitic change, urinary Ca/Cr, parathyroid hormone
and growth. It is very important to avoid side effects of these treatments. No evidence is
available about the optimal dose of phosphate or number of administrations in the
treatment of patients with hypophosphatemic rickets. Although there is a recommendation
for clinical management of patients with hypophosphatemic rickets, we should set a
clinical guideline for it in Japan.
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Affiliation(s)
- Makoto Fujiwara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
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