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Michigami T, Kang HG, Namba N, Ito N, Kubota T, Shintani A, Kabata D, Kanematsu M, Nishida Y, Fukumoto S, Ozono K. Burosumab treatment of X-linked hypophosphatemia patients: interim analysis of the SUNFLOWER longitudinal, observational cohort study. JBMR Plus 2024; 8:ziae079. [PMID: 39015507 PMCID: PMC11250265 DOI: 10.1093/jbmrpl/ziae079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 05/31/2024] [Accepted: 06/07/2024] [Indexed: 07/18/2024] Open
Abstract
X-linked hypophosphatemia (XLH) is a genetic disease that results in excessive FGF23, chronic hypophosphatemia, and musculoskeletal abnormalities, with affected patients experiencing symptoms such as bone pain, bone deformity, fracture, and pseudofracture. Burosumab is a fully human monoclonal antibody that binds to FGF23, improving lowered serum 1,25(OH)2D and phosphate levels in patients with XLH. There are insufficient data on the use of burosumab, its safety, and the outcomes of treated patients in a real-world setting. The SUNFLOWER (Study of longitUdinal observatioN For patients with X-Linked hypOphosphatemic rickets/osteomalacia in collaboration With Asian partnERs) study is an ongoing longitudinal, observational cohort study of patients with XLH in Japan and South Korea. Enrollment occurred between April 2018 and December 2020. This interim analysis compared the background characteristics of patients who received burosumab with those who did not, and assessed improvements in biomarkers, physical and motor function, health-related quality-of-life (HRQOL) and other patient-reported outcome (PRO) measures, as well as the safety of burosumab treatment in 143 Japanese patients from 15 institutions over 6 mo. The patients had a median [interquartile range] age of 17.5 [11.0, 38.8] yr and 98 (68.5%) were female. Among patients aged <18 and ≥18 yr, 40/73 (54.8%) and 25/70 (35.7%) received burosumab, respectively. More patients aged ≥18 who received burosumab had bone pain at baseline vs those not treated with burosumab (6/25, 24.0% vs 2/45, 4.4%, p=.021). Patients treated with burosumab had improved serum phosphate and 1,25(OH)2D levels; moreover, rickets severity and HRQOL/PRO measures, such as pain, appeared to improve over 6 mo of burosumab treatment, and no new safety concerns were identified. This study identified trends in the background characteristics of patients with XLH who receive burosumab in real-world clinical practice. Furthermore, the results support the use of burosumab therapy in real-world settings.
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Affiliation(s)
- Toshimi Michigami
- Department of Bone and Mineral Research, Osaka Women’s and Children’s Hospital, Osaka Prefectural Hospital Organization, Osaka 594-1101, Japan
| | - Hee Gyung Kang
- Department of Pediatric Nephrology, Seoul National University Children’s Hospital, Seoul 03080, Republic of Korea
| | - Noriyuki Namba
- Division of Pediatrics and Perinatology, Faculty of Medicine, Tottori University, Tottori 683-8504, Japan
| | - Nobuaki Ito
- Division of Therapeutic Development for Intractable Bone Diseases, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Takuo Kubota
- Department of Pediatrics, Graduate School of Medicine, Osaka University, Osaka 565-0871, Japan
| | - Ayumi Shintani
- Department of Medical Statistics, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
| | - Daijiro Kabata
- Department of Medical Statistics, Graduate School of Medicine, Osaka Metropolitan University, Osaka 545-8585, Japan
| | - Masanori Kanematsu
- Medical Affairs Department, Kyowa Kirin Co., Ltd., Tokyo 100-0004, Japan
| | - Yayoi Nishida
- Medical Affairs Department, Kyowa Kirin Co., Ltd., Tokyo 100-0004, Japan
| | - Seiji Fukumoto
- Department of Diabetes and Endocrinology, Tamaki-Aozora Hospital, Tokushima 779-3125, Japan
| | - Keiichi Ozono
- Center for Promoting Treatment of Intractable Diseases, ISEIKAI International General Hospital, Osaka 530-0052, Japan
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Puente Ruiz N, Valero Díaz de Lamadrid MC, Riancho JA. Etiology of hypophosphatemia in adults. Med Clin (Barc) 2024:S0025-7753(24)00392-0. [PMID: 39025772 DOI: 10.1016/j.medcli.2024.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 05/13/2024] [Accepted: 05/15/2024] [Indexed: 07/20/2024]
Abstract
Long-term hypophosphatemia, defined by serum phosphorus (P) levels <2.5mg/dL, impairs the development and quality of mineralized tissue of the skeletal, dental, and auditory systems. P homeostasis depends mainly on intestinal absorption and renal excretion. Hypophosphatemia may be due to the redistribution of P to the intracellular space, increased renal losses, or decreased intestinal absorption. Hypophosphatemia can be categorized as acute or chronic, depending on the time course. Most cases, either acute or chronic, are due to acquired causes. However, some chronic cases may have a genetic origin. Accurate and early diagnosis, followed by adequate treatment, is essential to limit its negative effects on the body.
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Affiliation(s)
- Nuria Puente Ruiz
- Servicio de Medicina Interna, Hospital Universitario Marqués de Valdecilla; Departamento de Medicina y Psiquiatría, Universidad de Cantabria; Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER, ISCIII), Madrid, España.
| | - M Carmen Valero Díaz de Lamadrid
- Servicio de Medicina Interna, Hospital Universitario Marqués de Valdecilla; Departamento de Medicina y Psiquiatría, Universidad de Cantabria; Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, España
| | - José A Riancho
- Servicio de Medicina Interna, Hospital Universitario Marqués de Valdecilla; Departamento de Medicina y Psiquiatría, Universidad de Cantabria; Instituto de Investigación Marqués de Valdecilla (IDIVAL), Santander, España; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER, ISCIII), Madrid, España
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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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Modifying the diets of captive proboscis monkeys in a temperate zoo to reduce weight loss and renal disease. Primates 2023; 64:123-141. [PMID: 36357633 DOI: 10.1007/s10329-022-01031-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 10/12/2022] [Indexed: 11/12/2022]
Abstract
In animal husbandry, diets should help in maintaining a healthy body condition, support reproduction, and promote species-specific longevity. It is recommended to feed folivorous primates kept in zoos a high-fiber diet, i.e., leaves, although satisfying such a requirement is challenging in temperate regions because it is difficult to obtain fresh leaves, especially in autumn and winter. As equally important for their appropriate treatment, it is valuable to provide details of clinical reports of medical problems and pathological findings, although such clinical reports are rather limited. Therefore, in foregut-fermenting proboscis monkeys (Nasalis larvatus), we (1) described the individual clinical reports of renal disease and weight loss at the Yokohama Zoological Gardens in Japan, (2) determined the nutritional profile of the diets supplied to these animals because other potential triggers for their renal disease and weight loss could be excluded, (3) modified the diet regimen to minimize weight loss and the development of hypercalcemia and hypophosphatemia, and (4) assessed the effects of such dietary modification by comparing the body weight and the Ca and P concentrations and the Ca/P ratios in the blood before and after diet modification with a comparison of these measurements between zoo and free-ranging individuals. Based on the nutritional profile of the diets, we concluded that the reported cases of renal failure might be caused by consumption of leaves with a Ca/P ratio far above the appropriate level in autumn and winter. Additionally, the dietary modification of minerals and metabolizable energy achieved certain beneficial effects on zoo-kept proboscis monkeys.
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André J, Zhukouskaya VV, Lambert AS, Salles JP, Mignot B, Bardet C, Chaussain C, Rothenbuhler A, Linglart A. Growth hormone treatment improves final height in children with X-linked hypophosphatemia. Orphanet J Rare Dis 2022; 17:444. [PMID: 36544157 PMCID: PMC9768884 DOI: 10.1186/s13023-022-02590-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND/AIM Despite optimal conventional treatment (oral phosphate supplements and active vitamin D analogs), about 40-50% of children with well-controlled X-linked hypophosphatemia (XLH) show linear growth failure, making them less likely to achieve an acceptable final height. Here, we studied the hypothesis that rhGH treatment improves final height in children with XLH and growth failure. METHODS Two cohorts of children with XLH were included in this retrospective longitudinal analysis: (1) a cohort treated with rhGH for short stature (n = 34) and (2) a cohort not treated with rhGH (n = 29). The mean duration of rhGH treatment was 4.4 ± 2.9 years. We collected the auxological parameters at various time points during follow-up until final height. RESULTS In rhGH-treated children, 2 years of rhGH therapy was associated with a significant increase in height from - 2.4 ± 0.9 to - 1.5 ± 0.7 SDS (p < 0.001). Their mean height at rhGH discontinuation was - 1.2 ± 0.9 SDS and at final height was - 1.3 ± 0.9 SDS corresponding to 165.5 ± 6.4 cm in boys and 155.5 ± 6.3 cm in girls. Notably, the two groups had similar final heights; i.e., the final height in children not treated with rhGH being - 1.2 ± 1.1 SDS (165.4 ± 6.8 cm in boys and 153.7 ± 7.8 cm in girls), p = 0.7. CONCLUSION Treatment with rhGH permits to improve final height in children with XLH and growth failure, despite optimal conventional treatment. We propose therefore that rhGH therapy could be considered as an option for short stature in the context of XLH.
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Affiliation(s)
- Julia André
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France
| | - Volha V. Zhukouskaya
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France ,grid.508487.60000 0004 7885 7602Laboratory Orofacial Pathologies, Imaging and Biotherapies URP2496 and FHU-DDS-Net, Dental School, and Plateforme d’Imagerie du Vivant (PIV), Université Paris Cité, Montrouge, France
| | - Anne-Sophie Lambert
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France ,grid.413784.d0000 0001 2181 7253AP-HP, Medicine for Adolescents, Bicêtre Paris Saclay Hospital, Le Kremlin Bicêtre, France
| | - Jean-Pierre Salles
- grid.508721.9Unit of Endocrinology and Bone Diseases, Children Hospital, Toulouse University Hospital, CHU de Toulouse, Université de Toulouse, ERN BOND, INSERM UMR 1291/CNRS 5051, INFINITY Center, Toulouse, France
| | - Brigitte Mignot
- grid.411158.80000 0004 0638 9213Department of Pediatrics, CHU of Besancon, Besançon, France
| | - Claire Bardet
- grid.508487.60000 0004 7885 7602Laboratory Orofacial Pathologies, Imaging and Biotherapies URP2496 and FHU-DDS-Net, Dental School, and Plateforme d’Imagerie du Vivant (PIV), Université Paris Cité, Montrouge, France
| | - Catherine Chaussain
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France ,grid.508487.60000 0004 7885 7602Laboratory Orofacial Pathologies, Imaging and Biotherapies URP2496 and FHU-DDS-Net, Dental School, and Plateforme d’Imagerie du Vivant (PIV), Université Paris Cité, Montrouge, France ,grid.50550.350000 0001 2175 4109AP-HP, Reference Center for Rare Disorders of the Calcium and Phosphate Metabolism, Dental Medicine Department, Bretonneau Hospital, GHN-Universite de Paris, Paris, France
| | - Anya Rothenbuhler
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France
| | - Agnès Linglart
- grid.413784.d0000 0001 2181 7253AP-HP, Endocrinology and Diabetes for Children, Reference Center for Rare Diseases of Calcium and Phosphate Metabolism, DMU SEA, OSCAR Filière, EndoRare and BOND ERN, Bicêtre Paris Saclay Hospital, 78 Rue du Général Leclerc, 94270 Le Kremlin Bicêtre, France ,grid.460789.40000 0004 4910 6535INSERM, Physiologie Et Physiopathologie Endocrinienne, Bicêtre Paris Saclay Hospital, Paris Saclay University, Le Kremlin Bicêtre, France
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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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Jurca CM, Iuhas O, Kozma K, Petchesi CD, Zaha DC, Bembea M, Jurca S, Paul C, Jurca AD. Effects of Burosumab Treatment on Two Siblings with X-Linked Hypophosphatemia. Case Report and Literature Review. Genes (Basel) 2022; 13:genes13081392. [PMID: 36011303 PMCID: PMC9407333 DOI: 10.3390/genes13081392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/01/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022] Open
Abstract
X-linked hypophosphatemia (XLH) or vitamin D-resistant rickets (MIM#307800), is a monogenic disorder with X-linked inheritance. It is caused by mutations present in the Phosphate Regulating Endopeptidase Homolog X-Linked (PHEX) gene responsible for the degradation of the bone-derived hormone fibroblast growth factor 23 (FGF23) into inactive fragments, but the entire mechanism is currently unclear. The inactivation of the gene prevents the degradation of FGF23, causing increased levels of FGF23, which leads to decreased tubular reabsorbtion of phosphorus. Clinical aspects are growth delay, limb deformities, bone pain, osteomalacia, dental anomalies, and enthesopathy. Laboratory evaluation shows hypophosphatemia, elevated alkaline phosphatase (ALP), and normal serum calcium levels, whereas parathormone (PTH) may be normal or increased and FGF23 greatly increased. Conventional treatment consists of administration of oral phosphate and calcitriol. Treatment with Burosumab, a monoclonal antibody that binds to FGF23, reducing its activity, was approved in 2018. Methods. We describe a case of two siblings, a girl and a boy, diagnosed with XLH, monitored by the Genetic Department of the County Emergency Clinical Hospital since 2019. The clinical picture is suggestive for XLH, both siblings exhibiting short stature, lower limb curvature, bone pain, marked walking weakness, and fatigue. Radiological aspects showed marked deformity of the lower limbs: genu varum in the girl, genu varum and valgum in the boy. Laboratory investigations showed hypophosphathemia, hyperphosphaturia, elevated ALP, normal PTH, and highly increased FGF23 in both. DNA analysis performed on the two siblings revealed a nonsense mutation in exone 5 of the PHEX gene: NM_000444.6(PHEX):c.565C > T (p.Gln189Ter). Results. At the age of 13½ on 7 June 2021, the two children started treatment with Burosumab in therapeutic doses and were monitored clinically and biochemically at regular intervals according to the protocol established by the Endocrinology Commission of the Romanian Health Ministry. Conclusions. The first results of the Burosumab treatment in the two siblings are extremely encouraging and suggest a favorable long-term evolution under this treatment.
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Affiliation(s)
- Claudia Maria Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Oana Iuhas
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Kinga Kozma
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Regional Center of Medical Genetics Bihor, County Emergency Clinical Hospital Oradea, Romania, (Part of ERN THACA), 410469 Oradea, Romania
| | - Codruta Diana Petchesi
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
- Correspondence:
| | - Dana Carmen Zaha
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Marius Bembea
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Sanziana Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
| | - Corina Paul
- Department of Pediatrics, Victor Babes University of Medicine and Pharmacy, 300041 Timisoara, Romania
| | - Alexandru Daniel Jurca
- Faculty of Medicine and Pharmacy, Department of Preclinical Disciplines, 1 December Sq., University of Oradea, 410081 Oradea, Romania
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Del Pino M, Viterbo GL, Arenas MA, Perez Garrido N, Ramirez P, Marino R, Belgorosky A, Fano V. Growth in height and body proportion from birth to adulthood in hereditary hypophosphatemic rickets: a retrospective cohort study. J Endocrinol Invest 2022; 45:1349-1358. [PMID: 35226335 DOI: 10.1007/s40618-022-01768-9] [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: 02/20/2021] [Accepted: 02/14/2022] [Indexed: 10/19/2022]
Abstract
PURPOSE Patients with hereditary hypophosphatemic rickets are short and disproportionate and very little information is available on segmental growth, but the body disproportion at adulthood leads us to think that the growth velocity of legs is slower. METHODS A total of 96 children were included and molecular testing was carried out in 42. Children who reached adult height were classified into two groups according to their compliance to conventional treatment (phosphate supplement and calcitriol). Individual growth records of height and sitting height/height were plotted using Argentine reference data in 96 children and growth curves were estimated by fitting Preece-Baines Model 1 in 19 of the children. RESULTS Molecular testing revealed sequence deleterious alterations or large deletions in 36/42 patients. During childhood, 76% of children grew below - 1.88 standard deviation score (SDS) and 97% had body disproportion. During adolescence, the mean peak height velocity for the good and poor compliance to treatment groups was 7.8 (0.6) and 5.4 (0.4) cm/year in boys and 7.0 (0.7) and 5.2 (0.8) cm/year in girls, respectively. At adulthood, the median sitting height/height ratio was 2.32 and 6.21 SDS for the good and poor compliance to treatment groups, respectively. The mean pubertal growth spurt of the trunk was -0.8 (1.4) SDS, with a short pubertal growth spurt of - 1.8 (0.4) SDS for limbs in the good compliance group. Median adult height in 13/29 males and 30/67 females was -4.56 and -3.16 SDS, respectively. CONCLUSION For all patients the growth spurt was slower, secondary to a short growth spurt of limbs, reaching a short adult height with body disproportion that was more prominent in the poor compliance group.
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Affiliation(s)
- M Del Pino
- Growth and Development, Hospital Garrahan, Combate de los Pozos 1881 (1245), Buenos Aires, Argentina.
| | - G L Viterbo
- Endocrinology, Hospital Garrahan, Buenos Aires, Argentina
| | - M A Arenas
- Growth and Development, Hospital Garrahan, Combate de los Pozos 1881 (1245), Buenos Aires, Argentina
| | - N Perez Garrido
- Endocrinology Molecular Laboratory, Hospital Garrahan, Buenos Aires, Argentina
| | - P Ramirez
- Endocrinology Molecular Laboratory, Hospital Garrahan, Buenos Aires, Argentina
| | - R Marino
- Endocrinology Molecular Laboratory, Hospital Garrahan, Buenos Aires, Argentina
| | - A Belgorosky
- Endocrinology, Hospital Garrahan, Buenos Aires, Argentina
- CONICET, Hospital Garrahan, Buenos Aires, Argentina
| | - V Fano
- Growth and Development, Hospital Garrahan, Combate de los Pozos 1881 (1245), Buenos Aires, Argentina
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Fuente R, García-Bengoa M, Fernández-Iglesias Á, Gil-Peña H, Santos F, López JM. Cellular and Molecular Alterations Underlying Abnormal Bone Growth in X-Linked Hypophosphatemia. Int J Mol Sci 2022; 23:ijms23020934. [PMID: 35055123 PMCID: PMC8778463 DOI: 10.3390/ijms23020934] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/12/2022] [Accepted: 01/13/2022] [Indexed: 12/21/2022] Open
Abstract
X-linked hypophosphatemia (XLH), the most common form of hereditary hypophosphatemic rickets, is caused by inactivating mutations of the phosphate-regulating endopeptidase gene (PHEX). XLH is mainly characterized by short stature, bone deformities and rickets, while in hypophosphatemia, normal or low vitamin D levels and low renal phosphate reabsorption are the principal biochemical aspects. The cause of growth impairment in patients with XLH is not completely understood yet, thus making the study of the growth plate (GP) alterations necessary. New treatment strategies targeting FGF23 have shown promising results in normalizing the growth velocity and improving the skeletal effects of XLH patients. However, further studies are necessary to evaluate how this treatment affects the GP as well as its long-term effects and the impact on adult height.
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Affiliation(s)
- Rocío Fuente
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Institute of Physiology, Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - María García-Bengoa
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine Hannover, 30559 Hanover, Germany
| | - Ángela Fernández-Iglesias
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
| | - Helena Gil-Peña
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - Fernando Santos
- Division of Pediatrics, Department of Medicine, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain; (R.F.); (M.G.-B.); (Á.F.-I.); (H.G.-P.); (F.S.)
- Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), 33011 Oviedo, Spain
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), 33011 Oviedo, Spain
| | - José Manuel López
- Department of Morphology and Cellular Biology, Faculty of Medicine, University of Oviedo, 33006 Oviedo, Spain
- Correspondence:
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Lin X, Li S, Zhang Z, Yue H. Clinical and Genetic Characteristics of 153 Chinese Patients With X-Linked Hypophosphatemia. Front Cell Dev Biol 2021; 9:617738. [PMID: 34141703 PMCID: PMC8204109 DOI: 10.3389/fcell.2021.617738] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 04/16/2021] [Indexed: 11/27/2022] Open
Abstract
X-linked hypophosphatemia (XLH) is caused by inactivating mutations in the phosphate-regulating endopeptidase homolog, X-linked (PHEX) gene, resulting in an excess of circulating intact fibroblast growth factor-23 (iFGF-23) and a waste of renal phosphate. In the present study, we retrospectively reviewed the clinical and molecular features of 153 Chinese patients, representing 87 familial and 66 sporadic cases with XLH. A total of 153 patients with XLH presented with signs or symptoms at a median age of 18.0 months (range, 9.0 months–26.0 years). Lower-limb deformity was the most frequent clinical manifestation, accounting for 79.1% (121/153). Biochemical screening showed increased serum levels of iFGF23 in patients with XLH, with a wide variation ranging from 14.39 to 730.70 pg/ml. Median values of serum iFGF23 in pediatric and adult patients were 94.87 pg/ml (interquartile range: 74.27–151.86 pg/ml) and 72.82 pg/ml (interquartile range: 39.42–136.00 pg/ml), respectively. Although no difference in circulating iFGF23 levels between these two groups was observed (P = 0.062), the proportion of patients with high levels of circulating iFGF23 (>42.2 pg/ml) was greater in the pediatric group than in the adult group (P = 0.026). Eighty-eight different mutations in 153 patients were identified, with 27 (30.7%) being novel. iFGF23 levels and severity of the disease did not correlate significantly with truncating and non-truncating mutations or N-terminal and C-terminal PHEX mutations. This study provides a comprehensive description of the clinical profiles, circulating levels of iFGF23 and gene mutation features of patients with XLH, further enriching the genotypic spectrum of the diseases. The findings show no evident correlation of circulating iFGF23 levels with the age or disease severity in patients with XLH.
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Affiliation(s)
- Xiaoyun Lin
- Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, China
| | - Shanshan Li
- Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, China
| | - Zhenlin Zhang
- Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, China
| | - Hua Yue
- Shanghai Clinical Research Center of Bone Diseases, Department of Osteoporosis and Bone Diseases, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, Shanghai, China
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11
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Baroncelli GI, Zampollo E, Manca M, Toschi B, Bertelloni S, Michelucci A, Isola A, Bulleri A, Peroni D, Giuca MR. Pulp chamber features, prevalence of abscesses, disease severity, and PHEX mutation in X-linked hypophosphatemic rickets. J Bone Miner Metab 2021; 39:212-223. [PMID: 32772199 DOI: 10.1007/s00774-020-01136-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 07/27/2020] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Rickets, growth failure, and recurrent periapical abscesses with fistulae are main signs in patients with X-linked hypophosphatemic rickets (XLH). Prevalence of abscesses, pulp chamber features, biochemical findings, disease severity, and PHEX gene mutation were examined. MATERIALS AND METHODS Pulp chambers size, shape, and morphology were assessed by orthopantomography in XLH patients (n = 24, age 5.8 ± 1.6 years) and in sex and age-matched healthy controls (n = 23, age 6.2 ± 1.4 years). XLH patients received conventional treatment (3.5 ± 1.9 years). Pulp chamber features were assessed in teeth of primary dentition and in the permanent left mandibular first molar and compared with those of controls. Rickets severity score was assessed at wrist, knee, and ankle. RESULTS The mean pulp chamber area/tooth area ratio, mean pulp chamber height/pulp chamber width ratio, and prominence of pulp horns into the tooth crown in primary and secondary molars were significantly higher in patients than in controls and in patients suffered abscesses than in patients without abscesses. Sixteen patients (67%) had a history of abscesses; incisors were affected more than canines and molars. Severity of rickets and mean serum parathyroid hormone (PTH) levels were significantly higher, and mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] levels significantly lower in patients suffered abscesses than in patients without abscesses. PHEX gene mutations were not correlated with dental phenotype and disease severity. CONCLUSION Enlarged pulp chambers with altered shape and morphology affected the majority of XLH patients predisposing to recurrent periapical abscesses with fistulae. Dental phenotype was associated with severity of rickets, high serum PTH, and low serum 1,25(OH)2D levels.
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Affiliation(s)
- Giampiero I Baroncelli
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy.
| | - Elisa Zampollo
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
| | - Mario Manca
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Benedetta Toschi
- Division of Medical Genetics, Department of Medical and Oncological Area, University-Hospital, Pisa, Italy
| | - Silvano Bertelloni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Angela Michelucci
- Unit of Molecular Genetics, Department of Laboratory Medicine, University-Hospital, Pisa, Italy
| | - Alessandro Isola
- Unit of Orthopedics, Usl Northwest-Tuscany, Versilia Hospital, Camaiore, Italy
| | - Alessandra Bulleri
- Unit of Radiodiagnostic, Department of Diagnostic Imaging, University-Hospital, Pisa, Italy
| | - Diego Peroni
- Division of Pediatrics, Endocrine Unit, Department of Obstetrics, Gynecology and Pediatrics, University-Hospital, Via Roma 67, 56126, Pisa, Italy
| | - Maria Rita Giuca
- Division of Dentistry and Oral Surgery, Department of Surgical Specialties, University-Hospital, Pisa, Italy
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12
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Dahir K, Roberts MS, Krolczyk S, Simmons JH. X-Linked Hypophosphatemia: A New Era in Management. J Endocr Soc 2020; 4:bvaa151. [PMID: 33204932 PMCID: PMC7649833 DOI: 10.1210/jendso/bvaa151] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 10/07/2020] [Indexed: 01/29/2023] Open
Abstract
X-linked hypophosphatemia (XLH) is a rare, hereditary, progressive musculoskeletal disease that often causes pain and short stature, as well as decreased physical function, mobility, and quality of life. Hypophosphatemia in XLH is caused by loss of function mutations in the phosphate-regulating endopeptidase homolog X-linked (PHEX) gene, resulting in excess levels of the phosphate-regulating hormone fibroblast growth factor 23 (FGF23), which leads to renal phosphate wasting and decreased serum 1,25-dihydroxyvitamin D production. Historically, treatment options were limited to oral phosphate and active vitamin D analogues (conventional management) dosed several times daily in an attempt to improve skeletal mineralization by increasing serum phosphorus. The recent approval of burosumab, a fully human monoclonal antibody to FGF23, has provided a new, targeted treatment option for patients with XLH. This review summarizes our current understanding of XLH, the safety and efficacy of conventional management and burosumab, existing recommendations for managing patients, and unanswered questions in the field.
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Affiliation(s)
- Kathryn Dahir
- Endocrinology and Diabetes, Vanderbilt University Medical Center, Nashville, Tennessee
| | | | | | - Jill H Simmons
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
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13
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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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14
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Jandhyala R. A novel method for observing proportional group awareness and consensus of items arising from list-generating questioning. Curr Med Res Opin 2020; 36:883-893. [PMID: 32098506 DOI: 10.1080/03007995.2020.1734920] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background: Current healthcare professional consensus-generating methodologies work by forcing consensus, which risks corrupting original opinions and often fails to assess prior expert knowledge awareness. Experience gained with a novel method in a progressive life-long rare disease, X-linked hypophosphataemia, which addresses these risks is presented here.Methods: Four case-studies are reported, presenting a novel methodology comprised of two survey rounds. Round 1 generated a list of items from healthcare professionals in response to an open-ended research question, alongside systematic literature reviews (when appropriate). These responses were thematically coded into mutually exclusive items then used to develop a structured questionnaire (Round 2), for which each participant identified their level of agreement using Likert scales; all responses were analyzed anonymously. Item awareness, observed agreement, consensus and prompted agreement were objectively measured.Results: The free-text responses to Round 1 tested the awareness of specific items regarding establishing a European registry for X-linked Hypophosphatemia (XLH), limitations of empirical treatment for XLH (adults and paediatrics), and triggers for treatment of XLH in adults. The four cases showed different levels of item awareness, observed consensus and degrees of prompted agreement. All participants agreed or strongly agreed with statements based on the most frequent items listed in Round 1. Less frequent Round 1 items had various degrees of prompted agreement consensus; some did not reach the consensus threshold of >50% participant agreement.Conclusions: Observed proportional group awareness and consensus is quicker than the Delphi technique and its variants, providing objective assessments of expert knowledge and standardized categorization of items regarding awareness, consensus and prompting. Further, it offers tailored management of each item in terms of educational need and further investigation.
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15
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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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16
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Martín Ramos S, Gil-Calvo M, Roldán V, Castellano Martínez A, Santos F. Positive Response to One-Year Treatment With Burosumab in Pediatric Patients With X-Linked Hypophosphatemia. Front Pediatr 2020; 8:48. [PMID: 32133333 PMCID: PMC7040476 DOI: 10.3389/fped.2020.00048] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 01/29/2020] [Indexed: 12/15/2022] Open
Abstract
X-linked hypophosphatemia (XLH) causes significant burden in pediatric patients in spite of maintained treatment with phosphate supplements and vitamin D derivatives. Administration of burosumab has shown promising results in clinical trial but studies assessing its effect in the everyday practice are missing. With this aim, we analyzed the response to one-year treatment with burosumab, injected subcutaneously at 0.8 mg/kg every 2 weeks, in five children (three females) aged from 6 to 16 years, with genetically confirmed XLH. Patients were being treated with phosphate and vitamin D analogs until the beginning of burosumab treatment. In all children, burosumab administration led to normalization of serum phosphate in association with marked increase of tubular reabsorption of phosphate and reduction of elevated serum alkaline phosphatase levels. Baseline height of patients, from -3.56 to -0.46 SD, increased in the three prepubertal children (+0.84, +0.89, and +0.16 SD) during burosumab treatment. Growth improvement was associated with reduction in body mass index (-1.75, -1.47, and -0.17 SD, respectively), suggesting a salutary effect of burosumab on physical activity and body composition. Burosumab was well-tolerated, mild local pain at the injection site and transient and mild headache following the initial doses of burosumab being the only reported undesirable side effects. No patient exhibited hyperphosphatemia, progression of nephrocalcinosis, worsening of metabolic control or developed hyperparathyroidism. Mild elevation of serum PTH present at the beginning of treatment in one patient 4 was not modified by burosumab administration. These results indicate that in the clinical setting, beyond the strict conditions and follow-up of clinical trials, burosumab treatment for 1 year exerts positive effects in pediatric patients with XLH without major adverse events.
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Affiliation(s)
| | - Marta Gil-Calvo
- Hospital Clínico Universitario de Santiago, Santiago de Compostela, Spain
| | | | | | - Fernando Santos
- Hospital Universitario Central de Asturias, Oviedo, Spain.,Instituto de Investigación Sanitaria del Principado de Asturias, Oviedo, Spain.,Universidad de Oviedo, Oviedo, Spain
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17
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Lambert AS, Zhukouskaya V, Rothenbuhler A, Linglart A. X-linked hypophosphatemia: Management and treatment prospects. Joint Bone Spine 2019; 86:731-738. [DOI: 10.1016/j.jbspin.2019.01.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2018] [Indexed: 12/21/2022]
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18
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Delucchi Á, Toro L, Alzamora R, Barrientos V, González M, Andaur R, León P, Villanueva F, Galindo M, Las Heras F, Montecino M, Moena D, Lazcano A, Pinto V, Salas P, Reyes ML, Mericq V, Michea L. Glucocorticoids Decrease Longitudinal Bone Growth in Pediatric Kidney Transplant Recipients by Stimulating the FGF23/FGFR3 Signaling Pathway. J Bone Miner Res 2019; 34:1851-1861. [PMID: 31099911 DOI: 10.1002/jbmr.3761] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 05/05/2019] [Accepted: 05/11/2019] [Indexed: 12/11/2022]
Abstract
Renal transplantation (RTx) is an effective therapy to improve clinical outcomes in pediatric patients with terminal chronic kidney disease. However, chronic immunosuppression with glucocorticoids (GCs) reduces bone growth and BMD. The mechanisms causing GC-induced growth impairment have not been fully clarified. Fibroblast growth factor 23 (FGF23) is a peptide hormone that regulates phosphate homeostasis and bone growth. In pathological conditions, FGF23 excess or abnormal FGF receptors (FGFR) activity leads to bone growth impairment. Experimental data indicate that FGF23 expression is induced by chronic GC exposure. Therefore, we hypothesize that GCs impair bone growth by increasing FGF23 expression, which has direct effects on bone growth plate. In a post hoc analysis of a multicentric randomized clinical trial of prepubertal RTx children treated with early GC withdrawal or chronic GC treatment, we observed that GC withdrawal was associated with improvement in longitudinal growth and BMD, and lower plasma FGF23 levels as compared with a chronic GC group. In prepubertal rats, GC-induced bone growth retardation correlated with increased plasma FGF23 and bone FGF23 expression. Additionally, GC treatment decreased FGFR1 expression whereas it increased FGFR3 expression in mouse tibia explants. The GC-induced bone growth impairment in tibiae explants was prevented by blockade of FGF23 receptors using either a pan-FGFR antagonist (PD173074), a C-terminal FGF23 peptide (FGF23180-205) which blocks the binding of FGF23 to the FGFR-Klotho complex or a specific FGFR3 antagonist (P3). Finally, local administration of PD173074 into the tibia growth plate ameliorated cartilage growth impairment in GC-treated rats. These results show that GC treatment partially reduces longitudinal bone growth via upregulation of FGF23 and FGFR3 expression, thus suggesting that the FGF23/Klotho/FGFR3 axis at the growth plate could be a potential therapeutic target for the management of GC-induced growth impairment in children.
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Affiliation(s)
- Ángela Delucchi
- Division of Nephrology, Hospital Luis Calvo Mackenna, Santiago, Chile.,Division of Nephrology, Clínica Alemana de Santiago, Santiago, Chile
| | - Luis Toro
- Division of Nephrology, Department of Medicine, Hospital Clínico Universidad de Chile, Santiago, Chile.,Centro de Investigación Clínica Avanzada, Hospital Clínico Universidad de Chile, Santiago, Chile.,Clinica Las Condes, Santiago, Chile
| | - Rodrigo Alzamora
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Victor Barrientos
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Magdalena González
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Rodrigo Andaur
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Pablo León
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Francisco Villanueva
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Mario Galindo
- Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy (MIII), Santiago, Chile
| | - Facundo Las Heras
- Clinica Las Condes, Santiago, Chile.,Department of Anatomic Pathology, Hospital Clínico Universidad de Chile, Santiago, Chile
| | - Martín Montecino
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andrés Bello, Santiago, Chile.,FONDAP Center for Genome Regulation, Universidad Andres Bello, Santiago, Chile
| | - Daniel Moena
- Institute of Biomedical Sciences, Faculty of Medicine and Faculty of Life Sciences, Universidad Andrés Bello, Santiago, Chile.,FONDAP Center for Genome Regulation, Universidad Andres Bello, Santiago, Chile
| | - Andrea Lazcano
- Division of Nephrology, Clínica Alemana de Santiago, Santiago, Chile.,Division of Nephrology, Hospital de Niños Roberto del Río, Santiago, Chile
| | - Viola Pinto
- Clinica Las Condes, Santiago, Chile.,Pediatric Nephrology Unit, Hospital Doctor Exequiel González Cortés, Santiago, Chile
| | - Paulina Salas
- Pediatric Nephrology Unit, Hospital Doctor Exequiel González Cortés, Santiago, Chile
| | - María Loreto Reyes
- Pediatric Endocrinology Unit, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Verónica Mericq
- Clinica Las Condes, Santiago, Chile.,Institute of Maternal and Child Research, Universidad de Chile, Santiago, Chile
| | - Luis Michea
- Division of Nephrology, Department of Medicine, Hospital Clínico Universidad de Chile, Santiago, Chile.,Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.,Millennium Institute on Immunology and Immunotherapy (MIII), Santiago, Chile
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19
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Huang J, Bao X, Xia W, Zhu L, Zhang J, Ma J, Jiang N, Yang J, Chen Q, Jing T, Liu J, Ma D, Xu G. Functional analysis of a de novo mutation c.1692 del A of the PHEX gene in a Chinese family with X-linked hypophosphataemic rickets. Bone Joint Res 2019; 8:405-413. [PMID: 31537998 PMCID: PMC6719531 DOI: 10.1302/2046-3758.88.bjr-2018-0276.r1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Objectives X-linked hypophosphataemic rickets (XLHR) is a disease of impaired bone mineralization characterized by hypophosphataemia caused by renal phosphate wasting. The main clinical manifestations of the disorder are O-shaped legs, X-shaped legs, delayed growth, and bone pain. XLHR is the most common inheritable form of rickets, with an incidence of 1/20 000 in humans. It accounts for approximately 80% of familial cases of hypophosphataemia and serves as the prototype of defective tubular phosphate (PO43+) transport, due to extra renal defects resulting in unregulated FGF23 activity. XLHR is caused by loss-of-function mutations in the PHEX gene. The aim of this research was to identify the genetic defect responsible for familial hypophosphataemic rickets in a four-generation Chinese Han pedigree and to analyze the function of this mutation. Methods The genome DNA samples of all members in the pedigree were extracted from whole blood. We sequenced all exons of the PHEX and FGF23 genes, as well as the adjacent splice site sequence with Sanger sequencing. Next, we analyzed the de novo mutation c.1692 del A of the PHEX gene with an online digital service and investigated the mutant PHEX with SWISS-MODEL, immunofluorescence, and protein stability detection. Results Through Sanger sequencing, we found a de novo mutation, c.1692 del A, in exon 16 of the PHEX gene in this pedigree. This mutation can make the PHEX protein become unstable and decay rapidly, which results in familial XLHR. Conclusion We have found a de novo loss-of-function mutation, c.1692 del A, in exon 16 of the PHEX gene that can cause XLHR. Cite this article: J. Huang, X. Bao, W. Xia, L. Zhu, J. Zhang, J. Ma, N. Jiang, J. Yang, Q. Chen, T. Jing, J. Liu, D. Ma, G. Xu. Functional analysis of a de novo mutation c.1692 del A of the PHEX gene in a Chinese family with X-linked hypophosphataemic rickets. Bone Joint Res 2019;8:405–413. DOI: 10.1302/2046-3758.88.BJR-2018-0276.R1.
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Affiliation(s)
- Jianbo Huang
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Xiaogang Bao
- Department of Orthopedic Surgery, The Spine Surgical Center, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wenjun Xia
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Lingjun Zhu
- Department of Orthopedic Surgery, The Spine Surgical Center, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jin Zhang
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jing Ma
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Nan Jiang
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jichun Yang
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Qing Chen
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Tianrui Jing
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Jia Liu
- Department of Orthopedic Surgery, The Spine Surgical Center, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Duan Ma
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, China; Research Center for Birth Defects, Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Guohua Xu
- Department of Orthopedic Surgery, The Spine Surgical Center, Changzheng Hospital, Second Military Medical University, Shanghai, China
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Yin Z, Du J, Yu F, Xia W. Tumor-induced osteomalacia. Osteoporos Sarcopenia 2018; 4:119-127. [PMID: 30775554 PMCID: PMC6372818 DOI: 10.1016/j.afos.2018.12.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 12/02/2018] [Accepted: 12/04/2018] [Indexed: 12/30/2022] Open
Abstract
Tumor-induced osteomalacia (TIO), also known as oncogenic osteomalacia, is a rare paraneoplastic syndrome characterized by hypophosphatemia resulting from decreased tubular phosphate reabsorption, with a low or inappropriately normal level of active vitamin D. The culprit tumors of TIO could produce fibroblast growth factor 23 which plays a role in regulating renal Pi handling and 25-hydroxyvitamin D 1α-hydroxylase activity. Chronic hypophosphatemia could eventually lead to inadequate bone mineralization, presenting as osteomalacia. The diagnosis should be considered when patients manifest as hypophosphatemia and osteomalacia, or rickets and needs to be differentiated from other disorders of phosphate metabolism, such as the inhereditary diseases like X-linked hypophosphataemic rickets, autosomal dominant hypophosphataemic rickets, autosomal recessive hypophosphataemic rickets and acquired diseases like vitamin D deficiency. Localization of responsible tumors could be rather difficult since the vast majority are very small and could be everywhere in the body. A combination of thorough physical examination, laboratory tests and imaging techniques should be applied and sometimes a venous sampling may come into handy. The technology of somatostatin-receptor functional scintigraphy markedly facilitates the localization of TIO tumor. Patients undergoing complete removal of the causative neoplasm generally have favorable prognoses while a few have been reported to suffer from recurrence and metastasis. For those undetectable or unresectable cases, phosphate supplements and active vitamin D should be administrated and curative intended radiotherapy or ablation is optional.
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Affiliation(s)
| | | | | | - Weibo Xia
- Department of Endocrinology, Key Laboratory of Endocrinology, The National Commission of Health, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
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21
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The elevation of circulating fibroblast growth factor 23 without kidney disease does not increase cardiovascular disease risk. Kidney Int 2018; 94:49-59. [DOI: 10.1016/j.kint.2018.02.017] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 01/24/2018] [Accepted: 02/01/2018] [Indexed: 11/23/2022]
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Carpenter TO, Whyte MP, Imel EA, Boot AM, Högler W, Linglart A, Padidela R, Van't Hoff W, Mao M, Chen CY, Skrinar A, Kakkis E, San Martin J, Portale AA. Burosumab Therapy in Children with X-Linked Hypophosphatemia. N Engl J Med 2018; 378:1987-1998. [PMID: 29791829 DOI: 10.1056/nejmoa1714641] [Citation(s) in RCA: 292] [Impact Index Per Article: 48.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND X-linked hypophosphatemia is characterized by increased secretion of fibroblast growth factor 23 (FGF-23), which leads to hypophosphatemia and consequently rickets, osteomalacia, and skeletal deformities. We investigated burosumab, a monoclonal antibody that targets FGF-23, in patients with X-linked hypophosphatemia. METHODS In an open-label, phase 2 trial, we randomly assigned 52 children with X-linked hypophosphatemia, in a 1:1 ratio, to receive subcutaneous burosumab either every 2 weeks or every 4 weeks; the dose was adjusted to achieve a serum phosphorus level at the low end of the normal range. The primary end point was the change from baseline to weeks 40 and 64 in the Thacher rickets severity total score (ranging from 0 to 10, with higher scores indicating greater disease severity). In addition, the Radiographic Global Impression of Change was used to evaluate rachitic changes from baseline to week 40 and to week 64. Additional end points were changes in pharmacodynamic markers, linear growth, physical ability, and patient-reported outcomes and the incidence of adverse events. RESULTS The mean Thacher rickets severity total score decreased from 1.9 at baseline to 0.8 at week 40 with every-2-week dosing and from 1.7 at baseline to 1.1 at week 40 with every-4-week dosing (P<0.001 for both comparisons); these improvements persisted at week 64. The mean serum phosphorus level increased after the first dose in both groups, and more than half the patients in both groups had levels within the normal range (3.2 to 6.1 mg per deciliter [1.0 to 2.0 mmol per liter]) by week 6. Stable serum phosphorus levels were maintained through week 64 with every-2-week dosing. Renal tubular phosphate reabsorption increased from baseline in both groups, with an overall mean increase of 0.98 mg per deciliter (0.32 mmol per liter). The mean dose of burosumab at week 40 was 0.98 mg per kilogram of body weight with every-2-week dosing and 1.50 mg per kilogram with every-4-week dosing. Across both groups, the mean serum alkaline phosphatase level decreased from 459 U per liter at baseline to 369 U per liter at week 64. The mean standing-height z score increased in both groups, with greater improvement seen at all time points with every-2-week dosing (an increase from baseline of 0.19 at week 64) than with every-4-week dosing (an increase from baseline of 0.12 at week 64). Physical ability improved and pain decreased. Nearly all the adverse events were mild or moderate in severity. CONCLUSIONS In children with X-linked hypophosphatemia, treatment with burosumab improved renal tubular phosphate reabsorption, serum phosphorus levels, linear growth, and physical function and reduced pain and the severity of rickets. (Funded by Ultragenyx Pharmaceutical and Kyowa Hakko Kirin; ClinicalTrials.gov number, NCT02163577 ; EudraCT number, 2014-000406-35 ).
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Affiliation(s)
- Thomas O Carpenter
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Michael P Whyte
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Erik A Imel
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Annemieke M Boot
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Wolfgang Högler
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Agnès Linglart
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Raja Padidela
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - William Van't Hoff
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Meng Mao
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Chao-Yin Chen
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Alison Skrinar
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Emil Kakkis
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Javier San Martin
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
| | - Anthony A Portale
- From Yale University School of Medicine, New Haven, CT (T.O.C.); Shriners Hospital for Children and Division of Bone and Mineral Diseases, Department of Internal Medicine, Washington University School of Medicine, St. Louis (M.P.W.); Indiana University School of Medicine, Indianapolis (E.A.I.); University of Groningen, Groningen, the Netherlands (A.M.B.); Birmingham Children's Hospital, Birmingham (W. Högler), Royal Manchester Children's Hospital, Manchester (R.P.), and Great Ormond Street Hospital, London (W. van't Hoff) - all in the United Kingdom; Assistance Publique-Hôpitaux de Paris Hôpital Bicêtre, Paris (A.L.); and Ultragenyx Pharmaceutical, Novato (M.M., C.-Y.C., A.S., E.K., J.S.M.), and University of California at San Francisco, San Francisco (A.A.P.) - both in California
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Maia MLDA, Abreu ALS, Nogueira PCK, Val MLDMD, Carvalhaes JTDA, Andrade MCD. HYPOPHOSPHATEMIC RICKETS: CASE REPORT. ACTA ACUST UNITED AC 2018; 36:242-247. [PMID: 29617471 PMCID: PMC6038795 DOI: 10.1590/1984-0462/;2018;36;2;00009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/16/2017] [Indexed: 11/22/2022]
Abstract
OBJECTIVE Early diagnosis and immediate treatment of hypophosphatemic rickets is of utmost importance as it may prevent subsequent sequelae. This report aims at warning pediatricians to consider the presence of the disease. CASE DESCRIPTION Description of the metabolic profile, creatinine clearance, nutritional status, weight and body structure of a patient who presented the clinical-laboratorial characteristics of hypophosphatemic rickets and was followed in an outpatient clinic for tubulopathies over the period of 12 months. The patient had been bedridden for some time, was dependent on mechanical ventilation and presented an altered metabolic bone condition. Treatment was phosphate (initial: 65 mg/kg/day and final: 24,2 mg/kg/day), calcium (initial: 127 mg/kg/day, final: 48,4 mg/kg/day) and calcitriol (initial: 0.06 mcg/kg/day, final: 0.03 mcg/kg/day). The patient improved, evolving into spontaneous breathing and walking unaided. Laboratory results: calcium (mg/dL) initial 7.1, final 10.1; phosphate (mg/dL) initial 1.7 final 3.2; magnesium (mg/dL) initial 1.5 final 2.1, parathyroid hormone (pg/l) initial 85.8, final 52.7, alkaline phosphatase (UI/l) initial 12660, final 938; there was also improvement in weight/structural development (Z score: H/A initial: -6.05, final -3.64; W/A: initial -2.92, final -1.57) with presence of transitory gallstones. Creatinine clearance (mL/min/1.73m2bsa) was constant. The medication improved his laboratory results and nutritional status, but the patient did not return for two years for follow-up and, during this period, his condition has noticeably deteriorated. COMMENTS Early diagnosis and follow-up are essential in dealing with this pathology.
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Lempicki M, Rothenbuhler A, Merzoug V, Franchi-Abella S, Chaussain C, Adamsbaum C, Linglart A. Magnetic Resonance Imaging Features as Surrogate Markers of X-Linked Hypophosphatemic Rickets Activity. Horm Res Paediatr 2018; 87:244-253. [PMID: 28376474 DOI: 10.1159/000464142] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 02/08/2017] [Indexed: 12/14/2022] Open
Abstract
OBJECTIVE X-linked hypophosphatemic rickets (XLH) is the most common form of inheritable rickets. Rickets treatment is monitored by assessing alkaline phosphatase (ALP) levels, clinical features, and radiographs. Our objectives were to describe the magnetic resonance imaging (MRI) features of XLH and to assess correlations with disease activity. STUDY DESIGN Twenty-seven XLH patients (median age 9.2 years) were included in this prospective single-center observational study. XLH activity was assessed using height, leg bowing, dental abscess history, and serum ALP levels. We looked for correlations between MRI features and markers of disease activity. RESULTS On MRI, the median maximum width of the physis was 5.6 mm (range 4.8-7.8; normal <1.5), being >1.5 mm in all of the patients. The appearance of the zone of provisional calcification was abnormal on 21 MRI images (78%), Harris lines were present on 24 (89%), and bone marrow signal abnormalities were present on 16 (59%). ALP levels correlated with the maximum physeal widening and with the transverse extent of the widening. CONCLUSIONS MRI of the knee provides precise rickets patterns that are correlated with ALP, an established biochemical marker of the disease, avoiding X-ray exposure and providing surrogate quantitative markers of disease activity.
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Affiliation(s)
- Marta Lempicki
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Radiology, Le Kremlin-Bicêtre, France
| | - Anya Rothenbuhler
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Endocrinology, Diabetology and Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR and Platform of Expertise Paris-Sud for Rare Diseases, Le Kremlin-Bicêtre, France
| | - Valérie Merzoug
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Radiology, Le Kremlin-Bicêtre, France
| | - Stéphanie Franchi-Abella
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Radiology, Le Kremlin-Bicêtre, France.,LTCI Telecom Paris Tech, Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Catherine Chaussain
- AP-HP, Bretonneau Hospital, Odontology Department, Paris, France.,Paris Descartes University, EA2496, Montrouge, France
| | - Catherine Adamsbaum
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Radiology, Le Kremlin-Bicêtre, France.,Paris-Sud University, Medical School, Le Kremlin-Bicêtre, France.,LTCI Telecom Paris Tech, Paris Saclay University, Le Kremlin-Bicêtre, France
| | - Agnès Linglart
- AP-HP, Bicêtre Paris-Sud Hospital, Department of Pediatric Endocrinology, Diabetology and Reference Center for Rare Disorders of Calcium and Phosphate Metabolism, Filière OSCAR and Platform of Expertise Paris-Sud for Rare Diseases, Le Kremlin-Bicêtre, France.,Paris-Sud University, Medical School, Le Kremlin-Bicêtre, France.,Inserm U1169, Bicêtre Paris-Sud Hospital and Paris-Saclay University, Le Kremlin-Bicêtre, France
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25
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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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26
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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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27
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Sanchez CP, Mohan S. Genetic Knockout and Rescue Studies in Mice Unravel Abnormal Phosphorus Threshold in Hypophosphatemic Rickets. Endocrinology 2017; 158:455-457. [PMID: 28430915 PMCID: PMC5460786 DOI: 10.1210/en.2017-00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 01/11/2017] [Indexed: 11/19/2022]
Affiliation(s)
| | - Subburaman Mohan
- Medicine, and
- Orthopedics, Loma Linda University, Loma Linda, California 92354; and
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, Loma Linda, California 92357
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28
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Fuente R, Gil-Peña H, Claramunt-Taberner D, Hernández O, Fernández-Iglesias A, Alonso-Durán L, Rodríguez-Rubio E, Santos F. X-linked hypophosphatemia and growth. Rev Endocr Metab Disord 2017; 18:107-115. [PMID: 28130634 DOI: 10.1007/s11154-017-9408-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
X-Linked hypophosphatemia (XLH) is the most common form of hereditary rickets caused by loss-of function mutations in the PHEX gene. XLH is characterized by hypophosphatemia secondary to renal phosphate wasting, inappropriately low concentrations of 1,25 dihydroxyvitamin D and high circulating levels of fibroblast growth factor 23 (FGF23). Short stature and rachitic osseous lesions are characteristic phenotypic findings of XLH although the severity of these manifestations is highly variable among patients. The degree of growth impairment is not dependent on the magnitude of hypophosphatemia or the extent of legs´ bowing and height is not normalized by chronic administration of phosphate supplements and 1α hydroxyvitamin D derivatives. Treatment with growth hormone accelerates longitudinal growth rate but there is still controversy regarding the potential risk of increasing bone deformities and body disproportion. Treatments aimed at blocking FGF23 action are promising, but information is lacking on the consequences of counteracting FGF23 during the growing period. This review summarizes current knowledge on phosphorus metabolism in XLH, presents updated information on XLH and growth, including the effects of FGF23 on epiphyseal growth plate of the Hyp mouse, an animal model of the disease, and discusses growth hormone and novel FGF23 related therapies.
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Affiliation(s)
- R Fuente
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - H Gil-Peña
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain
| | - D Claramunt-Taberner
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - O Hernández
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - A Fernández-Iglesias
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - L Alonso-Durán
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - E Rodríguez-Rubio
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain
| | - F Santos
- Division of Pediatrics, Department of Medicine. Faculty of Medicine, University of Oviedo, Oviedo, Asturias, Spain.
- Department of Pediatrics, Hospital Universitario Central de Asturias (HUCA), Oviedo, Asturias, Spain.
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29
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Ma Y, Kirby BJ, Fairbridge NA, Karaplis AC, Lanske B, Kovacs CS. FGF23 Is Not Required to Regulate Fetal Phosphorus Metabolism but Exerts Effects Within 12 Hours After Birth. Endocrinology 2017; 158:252-263. [PMID: 27929669 PMCID: PMC5413075 DOI: 10.1210/en.2016-1369] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 12/07/2016] [Indexed: 01/01/2023]
Abstract
Loss of fibroblast growth factor-23 (FGF23) causes hyperphosphatemia, extraskeletal calcifications, and early mortality; excess FGF23 causes hypophosphatemia with rickets or osteomalacia. However, FGF23 may not be important during fetal development. FGF23 deficiency (Fgf23 null) and FGF23 excess (Phex null) did not alter fetal phosphorus or skeletal parameters. In this study, we further tested our hypothesis that FGF23 is not essential for fetal phosphorus regulation but becomes important after birth. Although coreceptor Klotho null adults have extremely high FGF23 concentrations, intact FGF23 was normal in Klotho null fetuses, as were fetal phosphorus and skeletal parameters and placental and renal expression of FGF23 target genes. Pth/Fgf23 double mutants had the same elevation in serum phosphorus as Pth null fetuses, as compared with normal serum phosphorus in Fgf23 nulls. We examined the postnatal time courses of Fgf23 null, Klotho null, and Phex null mice. Fgf23 nulls and Klotho nulls were normal at birth, but developed hyperphosphatemia, increased renal expression of NaPi2a and NaPi2c, and reduced renal phosphorus excretion between 5 and 7 days after birth. Parathyroid hormone remained normal. In contrast, excess FGF23 exerted effects in Phex null males within 12 hours after birth, with the development of hypophosphatemia, reduced renal expression of NaPi2a and NaPi2c, and increased renal phosphorus excretion. In conclusion, although FGF23 is present in the fetal circulation at levels that may equal adult values, and there is robust expression of FGF23 target genes in placenta and fetal kidneys, FGF23 itself is not an important regulator of fetal phosphorous metabolism.
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Affiliation(s)
- Yue Ma
- Faculty of Medicine–Endocrinology, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3V6, Canada;
| | - Beth J. Kirby
- Faculty of Medicine–Endocrinology, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3V6, Canada;
| | - Nicholas A. Fairbridge
- Faculty of Medicine–Endocrinology, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3V6, Canada;
| | - Andrew C. Karaplis
- McGill University and Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada; and
| | - Beate Lanske
- Division of Bone and Mineral Research, Harvard School of Dental Medicine, Boston, Massachusetts 02115
| | - Christopher S. Kovacs
- Faculty of Medicine–Endocrinology, Memorial University of Newfoundland, St. John’s, Newfoundland A1B 3V6, Canada;
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30
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Witten PE, Owen MAG, Fontanillas R, Soenens M, McGurk C, Obach A. A primary phosphorus-deficient skeletal phenotype in juvenile Atlantic salmon Salmo salar: the uncoupling of bone formation and mineralization. JOURNAL OF FISH BIOLOGY 2016; 88:690-708. [PMID: 26707938 PMCID: PMC4784172 DOI: 10.1111/jfb.12870] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 11/11/2015] [Indexed: 05/17/2023]
Abstract
To understand the effect of low dietary phosphorus (P) intake on the vertebral column of Atlantic salmon Salmo salar, a primary P deficiency was induced in post-smolts. The dietary P provision was reduced by 50% for a period of 10 weeks under controlled conditions. The animal's skeleton was subsequently analysed by radiology, histological examination, histochemical detection of minerals in bones and scales and chemical mineral analysis. This is the first account of how a primary P deficiency affects the skeleton in S. salar at the cellular and at the micro-anatomical level. Animals that received the P-deficient diet displayed known signs of P deficiency including reduced growth and soft, pliable opercula. Bone and scale mineral content decreased by c. 50%. On radiographs, vertebral bodies appear small, undersized and with enlarged intervertebral spaces. Contrary to the X-ray-based diagnosis, the histological examination revealed that vertebral bodies had a regular size and regular internal bone structures; intervertebral spaces were not enlarged. Bone matrix formation was continuous and uninterrupted, albeit without traces of mineralization. Likewise, scale growth continues with regular annuli formation, but new scale matrix remains without minerals. The 10 week long experiment generated a homogeneous osteomalacia of vertebral bodies without apparent induction of skeletal malformations. The experiment shows that bone formation and bone mineralization are, to a large degree, independent processes in the fish examined. Therefore, a deficit in mineralization must not be the only cause of the alterations of the vertebral bone structure observed in farmed S. salar. It is discussed how the observed uncoupling of bone formation and mineralization helps to better diagnose, understand and prevent P deficiency-related malformations in farmed S. salar.
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Affiliation(s)
- P E Witten
- Ghent University, Department of Biology, Ledeganckstraat 35, 9000, Ghent, Belgium
| | - M A G Owen
- Skretting Aquaculture Research Centre, P. O. Box 48, N-4001, Stavanger, Norway
| | - R Fontanillas
- Skretting Aquaculture Research Centre, P. O. Box 48, N-4001, Stavanger, Norway
| | - M Soenens
- Ghent University, Department of Biology, Ledeganckstraat 35, 9000, Ghent, Belgium
| | - C McGurk
- Skretting Aquaculture Research Centre, P. O. Box 48, N-4001, Stavanger, Norway
| | - A Obach
- Skretting Aquaculture Research Centre, P. O. Box 48, N-4001, Stavanger, Norway
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31
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Novel de novo nonsense mutation of the PHEX gene (p.Lys50Ter) in a Chinese patient with hypophosphatemic rickets. Gene 2015; 565:150-4. [DOI: 10.1016/j.gene.2015.03.066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/18/2015] [Accepted: 03/29/2015] [Indexed: 01/20/2023]
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32
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Kovacs CS. Bone development and mineral homeostasis in the fetus and neonate: roles of the calciotropic and phosphotropic hormones. Physiol Rev 2014; 94:1143-218. [PMID: 25287862 DOI: 10.1152/physrev.00014.2014] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mineral and bone metabolism are regulated differently in utero compared with the adult. The fetal kidneys, intestines, and skeleton are not dominant sources of mineral supply for the fetus. Instead, the placenta meets the fetal need for mineral by actively transporting calcium, phosphorus, and magnesium from the maternal circulation. These minerals are maintained in the fetal circulation at higher concentrations than in the mother and normal adult, and such high levels appear necessary for the developing skeleton to accrete a normal amount of mineral by term. Parathyroid hormone (PTH) and calcitriol circulate at low concentrations in the fetal circulation. Fetal bone development and the regulation of serum minerals are critically dependent on PTH and PTH-related protein, but not vitamin D/calcitriol, fibroblast growth factor-23, calcitonin, or the sex steroids. After birth, the serum calcium falls and phosphorus rises before gradually reaching adult values over the subsequent 24-48 h. The intestines are the main source of mineral for the neonate, while the kidneys reabsorb mineral, and bone turnover contributes mineral to the circulation. This switch in the regulation of mineral homeostasis is triggered by loss of the placenta and a postnatal fall in serum calcium, and is followed in sequence by a rise in PTH and then an increase in calcitriol. Intestinal calcium absorption is initially a passive process facilitated by lactose, but later becomes active and calcitriol-dependent. However, calcitriol's role can be bypassed by increasing the calcium content of the diet, or by parenteral administration of calcium.
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Affiliation(s)
- Christopher S Kovacs
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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33
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Correction of a genetic disease by CRISPR-Cas9-mediated gene editing in mouse spermatogonial stem cells. Cell Res 2014; 25:67-79. [PMID: 25475058 DOI: 10.1038/cr.2014.160] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 10/29/2014] [Accepted: 11/04/2014] [Indexed: 12/13/2022] Open
Abstract
Spermatogonial stem cells (SSCs) can produce numerous male gametes after transplantation into recipient testes, presenting a valuable approach for gene therapy and continuous production of gene-modified animals. However, successful genetic manipulation of SSCs has been limited, partially due to complexity and low efficiency of currently available genetic editing techniques. Here, we show that efficient genetic modifications can be introduced into SSCs using the CRISPR-Cas9 system. We used the CRISPR-Cas9 system to mutate an EGFP transgene or the endogenous Crygc gene in SCCs. The mutated SSCs underwent spermatogenesis after transplantation into the seminiferous tubules of infertile mouse testes. Round spermatids were generated and, after injection into mature oocytes, supported the production of heterozygous offspring displaying the corresponding mutant phenotypes. Furthermore, a disease-causing mutation in Crygc (Crygc(-/-)) that pre-existed in SSCs could be readily repaired by CRISPR-Cas9-induced nonhomologous end joining (NHEJ) or homology-directed repair (HDR), resulting in SSC lines carrying the corrected gene with no evidence of off-target modifications as shown by whole-genome sequencing. Fertilization using round spermatids generated from these lines gave rise to offspring with the corrected phenotype at an efficiency of 100%. Our results demonstrate efficient gene editing in mouse SSCs by the CRISPR-Cas9 system, and provide the proof of principle of curing a genetic disease via gene correction in SSCs.
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34
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Cañete R, Caballero-Villarraso J, Aguilar-Quintero M, Vázquez-Rueda F. Beneficial effects of growth hormone therapy for ossification defects after bone distraction in X linked hypophosphataemic rickets. BMJ Case Rep 2014; 2014:bcr-2013-203069. [PMID: 25115781 DOI: 10.1136/bcr-2013-203069] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A report on two homozygous twin girls affected by X linked hypophosphataemic rickets. They were examined due to short stature and genu varum of both tibias. They were treated with calcitriol and Joulie's solution, whereon it was observed that serum parathyroid hormone and phosphaturia decreased while phosphataemia increased. They underwent a tibial osteotomy (by means of the insertion of Kirchner needles) at 7.7 years of age for correction of genu varum and a normal consolidation was reached 1 month later. Nonetheless, height was percentile <1 after menarche, so both sisters asked for bone lengthening. Because of this, at 15 years of age femoral distraction was performed, but no bone callus was observed 14 months later. Consequently, they were treated with subcutaneous growth hormone, showing bone callus at 6 months. Finally, the external fixators were removed due to ossification in the lengthened segments.
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Affiliation(s)
- Ramón Cañete
- Pediatric Endocrinology Unit, IMIBIC/Reina Sofía Hospital/Córdoba University, Córdoba, Spain
| | | | - María Aguilar-Quintero
- Pediatric Endocrinology Unit, IMIBIC/Reina Sofía Hospital/Córdoba University, Córdoba, Spain
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35
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Abstract
Aberrant redeployment of the 'transient' events responsible for bone development and postnatal longitudinal growth has been reported in some diseases in what is otherwise inherently 'stable' cartilage. Lessons may be learnt from the molecular mechanisms underpinning transient chondrocyte differentiation and function, and their application may better identify disease aetiology. Here, we review the current evidence supporting this possibility. We firstly outline endochondral ossification and the cellular and physiological mechanisms by which it is controlled in the postnatal growth plate. We then compare the biology of these transient cartilaginous structures to the inherently stable articular cartilage. Finally, we highlight specific scenarios in which the redeployment of these embryonic processes may contribute to disease development, with the foresight that deciphering those mechanisms regulating pathological changes and loss of cartilage stability will aid future research into effective disease-modifying therapies.
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Affiliation(s)
- K A Staines
- (Correspondence should be addressed to K A Staines; )
| | | | | | - C Farquharson
- Comparative Biomedical Sciences, The Royal Veterinary CollegeRoyal College Street, London, NW1 0TUUK
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