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Abstract
Vitamin D metabolism represents a well-integrated, hormonally regulated endocrine unit interlinking calcium and phosphate metabolism. Pathophysiologic processes disturbing vitamin D metabolism comprise classic defects of vitamin D activation and action presenting as different forms of vitamin D-dependent rickets as well as disorders with increased vitamin D activity. The latter may result in hypercalcemia, hypercalciuria, and renal calcifications. Acquired and hereditary disorders causing hypervitaminosis D are discussed, including vitamin D intoxication, granulomatous disease, and idiopathic infantile hypercalcemia that may be caused by either a defective vitamin D degradation or by a primary defect in phosphate conservation.
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Affiliation(s)
- Karl Peter Schlingmann
- Department of General Pediatrics, University Children's Hospital, Albert-Schweitzer-Campus 1, Münster 48149, Germany.
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Schlingmann KP, Cassar W, Konrad M. Juvenile onset IIH and CYP24A1 mutations. Bone Rep 2018; 9:42-46. [PMID: 30591926 PMCID: PMC6303532 DOI: 10.1016/j.bonr.2018.06.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/13/2018] [Accepted: 06/16/2018] [Indexed: 12/23/2022] Open
Abstract
The term Idiopathic infantile hypercalcemia (IIH) was first introduced almost 70 years ago when symptomatic hypercalcemia developed in children after receiving high doses of vitamin D for the prevention of rickets. The underlying pathophysiology remained unknown until recessive mutations in CYP24A1 encoding Vitamin D3-24-hydroxylase were discovered. The defect in vitamin D degradation leads to an accumulation of active 1,25(OH)2D3 with subsequent hypercalcemia. Enhanced renal calcium excretions lead to hypercalciuria and nephrocalcinosis. Meanwhile, the phenotypic spectrum associated with CYP24A1 mutations has significantly broadened. Patients may present at all age groups with symptoms originating from increased serum calcium levels as well as from increased urinary calcium excretions, i.e. kidney stones. Possible long term sequelae comprise chronic renal failure as well as cardiovascular disease. Here, we present a family with two affected siblings with differing clinical presentation as an example for the phenotypic variability of CYP24A1 defects. CYP24A1 mutations result in increased vitamin D sensitivity. Associated phenotypes range from infantile hypercalcemia to kidney stone disease. Potential long-term sequelae include chronic renal failure. Future research needs to focus on potential treatments to limit vitamin D activation.
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Affiliation(s)
- Karl P Schlingmann
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
| | | | - Martin Konrad
- Department of General Pediatrics, University Children's Hospital, Münster, Germany
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De Paolis E, Minucci A, De Bonis M, Scaglione GL, Gervasoni J, Primiano A, Ferraro PM, Cappellani D, Marcocci C, Gambaro G, Capoluongo E. A rapid screening of a recurrent CYP24A1 pathogenic variant opens the way to molecular testing for Idiopathic Infantile Hypercalcemia (IIH). Clin Chim Acta 2018; 482:8-13. [PMID: 29574006 DOI: 10.1016/j.cca.2018.03.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 03/09/2018] [Accepted: 03/20/2018] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Loss-of-function mutations in cytochrome P450 family 24 subfamily A member 1 (CYP24A1) gene are associated with Idiopathic Infantile Hypercalcemia (IIH) and adult kidney stone disease. The enzyme deficiency leads to an impaired vitamin D catabolism pathway, resulting in a syndrome characterized by recurrent hypercalcemia, hypercalciuria and suppressed parathyroid hormone (PTH) levels. In these patients, the genetic evaluation of CYP24A1 is an important diagnostic tool, allowing the definitive diagnosis of IIH. METHODS A rapid CYP24A1 gene testing based on High Resolution Melting Analysis (HRMA) was designed in order to detect the CYP24A1 c.428_430delAAG (p.Glu143del), a recurrent IIH-associated variant. RESULTS HRMA method was able to identify c.428_430delAAG genotypes evaluating melting curve shape and melting temperature (Tm). Heterozygous samples exhibited a typical melting profile while homozygous samples showed a specific Tm shift. CONCLUSIONS We provide evidence about application of HRMA in unambiguous genotyping of the CYP24A1 c.428_430delAAG variant, making this method useful in clinical molecular diagnostics. This approach opens the way to a helpful molecular analysis of CYP24A1 gene in IIH diagnosis, to an improved pharmacological treatment strategy and to a reduced risk of recurrent stones and worsening nephrocalcinosis.
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Affiliation(s)
- Elisa De Paolis
- Polo Scienze delle Immagini, di Laboratorio ed Infettivologiche, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Angelo Minucci
- Polo Scienze delle Immagini, di Laboratorio ed Infettivologiche, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Maria De Bonis
- Polo Scienze delle Immagini, di Laboratorio ed Infettivologiche, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Giovanni Luca Scaglione
- Laboratory of Molecular Oncology, "Giovanni Paolo II" Foundation, Catholic University of Sacred Heart, Campobasso, Italy
| | - Jacopo Gervasoni
- Polo Scienze delle Immagini, di Laboratorio ed Infettivologiche, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Aniello Primiano
- Polo Scienze delle Immagini, di Laboratorio ed Infettivologiche, Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Pietro Manuel Ferraro
- Polo di Scienze Reumatologiche, Dermatologiche, Immuno-Allergologiche, Urologiche e Nefrologiche, Istituto di Medicina Interna e Geriatria. Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Daniele Cappellani
- Department of Clinical and Experimental Medicine, Section of Endocrinology, University of Pisa, Pisa, Italy
| | - Claudio Marcocci
- Department of Clinical and Experimental Medicine, Section of Endocrinology, University of Pisa, Pisa, Italy
| | - Giovanni Gambaro
- Polo di Scienze Reumatologiche, Dermatologiche, Immuno-Allergologiche, Urologiche e Nefrologiche, Istituto di Medicina Interna e Geriatria. Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy
| | - Ettore Capoluongo
- Laboratory of Clinical Pathology and Advanced Molecular Diagnostics, Istituto Dermopatico dell'Immacolata -IRCCS, Rome, Italy; Università Cattolica del Sacro Cuore, Fondazione Policlinico Universitario Agostino Gemelli, Roma, Italy.
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Ertl DA, Raimann A, Csaicsich D, Patsch JM, Laccone F, Haeusler G. A Pediatric Patient with a CYP24A1 Mutation: Four Years of Clinical, Biochemical, and Imaging Follow-Up. Horm Res Paediatr 2017; 87:196-204. [PMID: 27798933 DOI: 10.1159/000450947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 09/20/2016] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND A female infant was admitted to hospital due to failure to thrive. She presented hypercalcemia (4.09 mmol/L, normal range: 2.2-2.65 mmol/L), high 25-hydroxyvitamin D (283 nmol/L, normal range: 75-250 nmol/L), 1,25-dihydroxyvitamin D in the upper normal range, and low parathyroid hormone. Vitamin D intoxication was suspected. The patient had received routine rickets prophylaxis. METHODS Williams-Beuren syndrome was genetically excluded. Sequencing of CYP24A1 showed 2 mutations: c.443T>C and c.1186C>T. RESULTS The patient's clinical status improved after intravenous rehydration, cessation of supplementation, and on a low-calcium diet. 25-Hydroxyvitamin D concentrations normalized within days, while 1,25-dihydroxyvitamin D remained in the upper normal range. We also investigated our patient's bone health. CONCLUSION The patient was hospitalized initially on suspicion of vitamin D intoxication but proved to be a case of compound heterozygosity. Data on the long-term clinical and biochemical evolution of patients with idiopathic infantile hypercalcemia are sparse. Our follow-up showed seasonal variations of vitamin D and calcium parameters, with no influence on kidney function or bone health for the investigated period.
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Affiliation(s)
- Diana-Alexandra Ertl
- University Clinic for Pediatrics and Adolescent Medicine, Medical University of Vienna, Vienna, Austria
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Eliza MY, Shahruddin M, Noormaziah J, Rosli WDW. Carboxymethyl Cellulose (CMC) from Oil Palm Empty Fruit Bunch (OPEFB) in the new solvent Dimethyl Sulfoxide (DMSO)/Tetrabutylammonium Fluoride (TBAF). ACTA ACUST UNITED AC 2015. [DOI: 10.1088/1742-6596/622/1/012026] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Meusburger E, Mündlein A, Zitt E, Obermayer-Pietsch B, Kotzot D, Lhotta K. Medullary nephrocalcinosis in an adult patient with idiopathic infantile hypercalcaemia and a novel CYP24A1 mutation. Clin Kidney J 2013; 6:211-215. [PMID: 24175086 PMCID: PMC3811979 DOI: 10.1093/ckj/sft008] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 01/15/2013] [Indexed: 01/08/2023] Open
Abstract
Idiopathic infantile hypercalcaemia (IIH) is an autosomal recessively inherited disease, presented in the first year of life with hypercalcaemia, precipitated by normal amounts of vitamin D supplementation. Recently loss-of-function mutations in the CYP24A1 gene, which encodes the vitamin D-metabolizing enzyme 24-hydroxylase, have been found in these patients. We describe a young man homozygous for a novel missense mutation (c.628T>C) of the CYP24A1 gene. He had suffered from severe hypercalcaemia in early childhood. At age 29 he presented with medullary nephrocalcinosis, chronic kidney disease (CKD) stage 2, microalbuminuria, mild hypertension and nephrogenic diabetes insipidus. He had mild hypercalcaemia and moderate hypercalciuria. As a novel finding, fibroblast growth factor 23 (FGF23) was elevated.
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Affiliation(s)
- Edgar Meusburger
- Department of Nephrology and Dialysis , Academic Teaching Hospital Feldkirch , Feldkirch , Austria
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Infantile hypercalcemia and hypercalciuria: new insights into a vitamin D-dependent mechanism and response to ketoconazole treatment. J Pediatr 2010; 157:296-302. [PMID: 20394945 DOI: 10.1016/j.jpeds.2010.02.025] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Revised: 01/05/2010] [Accepted: 02/18/2010] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To analyze vitamin D metabolism and response to ketoconazole, an imidazole derivative that inhibits the vitamin D-1-hydroxylase, in infants with idiopathic hypercalcemia, and hypercalciuria. STUDY DESIGN Twenty infants (4 days-17 months) with hypercalcemia, severe hypercalciuria, and low parathyroid hormone level, (10 had nephrocalcinosis), including 10 treated with ketoconazole (3-9 mg/kg/day), were followed to the age of 2 to 51 months. Vitamin D receptor expression (VDR), 24-hydroxylase activity, and functional gene polymorphisms of vitamin D metabolism regulators VDR(rs4516035), 1-hydroxylase(rs10877012), 24-hydroxylase(rs2248359), FGF23(rs7955866), Klotho(rs9536314, rs564481, rs648202), were evaluated. RESULTS Serum calcium levels, which occurred faster in the ketoconazole group (0.7 +/- 0.2 versus 2.4 +/- 0.6 months; P = .0076), and urinary calcium excretion (2.5 +/- 0.5 versus 4.2 +/- 1.7 months) normalized in all patients. Serum 1,25-(OH)2D levels were high normal and positively correlated to 25-(OH)D levels. Serum 24,25-(OH)2D levels were low normal, and skin fibroblasts from 1 patient showed defective up-regulation of the 24-hydroxylase by 1,25-(OH)2D despite normal VDR binding ability. An abnormally low prevalence of haplotype CC/CC for H589H/A749A in Klotho gene was found in patients and family members. CONCLUSIONS Ketoconazole is a potentially useful and safe agent for treatment of infantile hypercalcemia. Abnormal vitamin D metabolism is suggested as the mechanism, possibly involving defective up-regulation of the 24-hydroxylase by 1,25-(OH)2D3, and the klotho-FGF23 axis.
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Lameris ALL, Huybers S, Burke JR, Monnens LA, Bindels RJM, Hoenderop JGJ. Involvement of claudin 3 and claudin 4 in idiopathic infantile hypercalcaemia: a novel hypothesis? Nephrol Dial Transplant 2010; 25:3504-9. [PMID: 20466674 DOI: 10.1093/ndt/gfq221] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Idiopathic infantile hypercalcaemia (IIH) is a rare disease that generally resolves spontaneously between the age of 1 and 3 years. Similar symptoms may occur in patients suffering from Williams-Beuren syndrome (WBS), which is caused by a microdeletion on chromosome 7. Two of the genes, named CLDN3 and CLDN4, located within this region are members of the claudin family that has been shown to be involved in paracellular calcium (Ca(2+)) absorption. Based on the hemizygous loss of CLDN3 and CLDN4 in WBS and the function of these genes in paracellular Ca(2+) transport, we hypothesized that mutations in CLDN3 or CLDN4 could also be involved in IIH. METHODS Biochemical characteristics, including calciotropic hormone levels, were obtained from three typical IIH patients. CLDN3 and CLDN4 sequences were also analysed in these patients. The major intestinal Ca(2+) transporter TRPV6 was also screened for the presence of mutations, since hypercalcaemia in IIH and WBS has been shown to result from intestinal hyperabsorption. All three patients were also analysed for the presence of deletions or duplications using a single-nucleotide polymorphism (SNP) array for genomic DNA. RESULTS The serum Ca(2+) levels of patients were 2.9, 3.3 and 3.8 mmol/L (normal <2.7 mmol/L). Levels of 25-hydroxyvitamin D(3) and 1,25-dihydroxyvitamin D(3) were normal, parathyroid hormone (PTH) and PTH-related peptide (PTHrP) levels were appropriately low. Sequencing of coding regions and intron-exon boundaries did not reveal mutations in CLDN3, CLDN4 and TRPV6. Identified SNPs were not correlated with the disease phenotype. A SNP array did not reveal genomic deletions or duplications. CONCLUSIONS Biochemical analysis did not reveal inappropriate levels of calciotropic hormones in IIH patients in this study. Furthermore, based on the lack of mutations in CLDN3, CLDN4 and TRPV6, we conclude that IIH is neither caused by mutations in these candidate genes nor by deletions or duplications in the genome of these patients.
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Affiliation(s)
- Anke L L Lameris
- Department of Physiology, Radboud University Nijmegen Medical Centre, The Netherlands
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Huang J, Coman D, McTaggart SJ, Burke JR. Long-term follow-up of patients with idiopathic infantile hypercalcaemia. Pediatr Nephrol 2006; 21:1676-80. [PMID: 16932902 DOI: 10.1007/s00467-006-0217-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2005] [Revised: 04/24/2006] [Accepted: 04/26/2006] [Indexed: 11/24/2022]
Abstract
Idiopathic infantile hypercalcaemia (IIH) is a rare disorder of unknown etiology that presents with hypercalcaemia in a child's first year of life. There is only a limited number of published reports of the natural history of this condition, and the long-term prognosis is largely unknown. The presentation, treatment and long-term follow-up of 11 children with IIH treated at our institution since 1993 are described. Hypercalcaemia resolved in the majority of children by the time they were 3 years of age, but nephrocalcinosis and persistent hypercalciuria were common, and, in some cases, urinary calcium excretion increased after initially becoming normal. This study suggests that clinical and biochemical abnormalities may persist for longer than previously reported and implies the need for ongoing surveillance of patients with IIH.
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Affiliation(s)
- Jianping Huang
- Queensland Child and Adolescent Renal Service, Royal Children's Hospital and Mater Children's Hospitals, Brisbane, Queensland, Australia
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Granja PL, Jéso BD, Bareille R, Rouais F, Baquey C, Barbosa MA. Cellulose phosphates as biomaterials. In vitro biocompatibility studies. REACT FUNCT POLYM 2006. [DOI: 10.1016/j.reactfunctpolym.2005.10.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Barbosa M, Granja P, Barrias C, Amaral I. Polysaccharides as scaffolds for bone regeneration. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.rbmret.2005.04.006] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Granja PL, Pouységu L, Pétraud M, De Jéso B, Baquey C, Barbosa MA. Cellulose phosphates as biomaterials. I. Synthesis and characterization of highly phosphorylated cellulose gels. J Appl Polym Sci 2001. [DOI: 10.1002/app.2193] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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