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Tian L, Andrews C, Yan Q, Yang JJ. Molecular regulation of calcium-sensing receptor (CaSR)-mediated signaling. Chronic Dis Transl Med 2024; 10:167-194. [PMID: 39027195 PMCID: PMC11252437 DOI: 10.1002/cdt3.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 03/29/2024] [Accepted: 04/09/2024] [Indexed: 07/20/2024] Open
Abstract
Calcium-sensing receptor (CaSR), a family C G-protein-coupled receptor, plays a crucial role in regulating calcium homeostasis by sensing small concentration changes of extracellular Ca2+, Mg2+, amino acids (e.g., L-Trp and L-Phe), small peptides, anions (e.g., HCO3 - and PO4 3-), and pH. CaSR-mediated intracellular Ca2+ signaling regulates a diverse set of cellular processes including gene transcription, cell proliferation, differentiation, apoptosis, muscle contraction, and neuronal transmission. Dysfunction of CaSR with mutations results in diseases such as autosomal dominant hypocalcemia, familial hypocalciuric hypercalcemia, and neonatal severe hyperparathyroidism. CaSR also influences calciotropic disorders, such as osteoporosis, and noncalciotropic disorders, such as cancer, Alzheimer's disease, and pulmonary arterial hypertension. This study first reviews recent advances in biochemical and structural determination of the framework of CaSR and its interaction sites with natural ligands, as well as exogenous positive allosteric modulators and negative allosteric modulators. The establishment of the first CaSR protein-protein interactome network revealed 94 novel players involved in protein processing in endoplasmic reticulum, trafficking, cell surface expression, endocytosis, degradation, and signaling pathways. The roles of these proteins in Ca2+-dependent cellular physiological processes and in CaSR-dependent cellular signaling provide new insights into the molecular basis of diseases caused by CaSR mutations and dysregulated CaSR activity caused by its protein interactors and facilitate the design of therapeutic agents that target CaSR and other family C G-protein-coupled receptors.
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Affiliation(s)
- Li Tian
- Department of Chemistry, Center for Diagnostics and Therapeutics, Advanced Translational Imaging FacilityGeorgia State UniversityAtlantaGeorgiaUSA
| | - Corey Andrews
- Department of Chemistry, Center for Diagnostics and Therapeutics, Advanced Translational Imaging FacilityGeorgia State UniversityAtlantaGeorgiaUSA
| | - Qiuyun Yan
- Department of Chemistry, Center for Diagnostics and Therapeutics, Advanced Translational Imaging FacilityGeorgia State UniversityAtlantaGeorgiaUSA
| | - Jenny J. Yang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Advanced Translational Imaging FacilityGeorgia State UniversityAtlantaGeorgiaUSA
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2
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Mayr B, Glaudo M, Schöfl C. Activating Calcium-Sensing Receptor Mutations: Prospects for Future Treatment with Calcilytics. Trends Endocrinol Metab 2016; 27:643-652. [PMID: 27339034 DOI: 10.1016/j.tem.2016.05.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Revised: 05/17/2016] [Accepted: 05/20/2016] [Indexed: 12/20/2022]
Abstract
Activating mutations of the G protein-coupled receptor, calcium-sensing receptor (CaSR), cause autosomal dominant hypocalcemia and Bartter syndrome type 5. These mutations lower the set-point for extracellular calcium sensing, thereby causing decreased parathyroid hormone secretion and disturbed renal calcium handling with hypercalciuria. Available therapies increase serum calcium levels but raise the risk of complications in affected patients. Symptom relief and the prevention of adverse outcome is currently very difficult to achieve. Calcilytics act as CaSR antagonists that attenuate its activity, thereby correcting the molecular defect of activating CaSR proteins in vitro and elevating serum calcium in mice and humans in vivo, and have emerged as the most promising therapeutics for the treatment of these rare and difficult to treat diseases.
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Affiliation(s)
- Bernhard Mayr
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany.
| | - Markus Glaudo
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany
| | - Christof Schöfl
- Division of Endocrinology and Diabetes, Department of Medicine I, Universitätsklinikum Erlangen, Friedrich-Alexander University Erlangen-Nuremberg, Germany
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3
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Jouret F, Wu J, Hull M, Rajendran V, Mayr B, Schöfl C, Geibel J, Caplan MJ. Activation of the Ca²+-sensing receptor induces deposition of tight junction components to the epithelial cell plasma membrane. J Cell Sci 2013; 126:5132-42. [PMID: 24013548 DOI: 10.1242/jcs.127555] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The Ca(2+)-sensing receptor (CaSR) belongs to the G-protein-coupled receptor superfamily and plays essential roles in divalent ion homeostasis and cell differentiation. Because extracellular Ca(2+) is essential for the development of stable epithelial tight junctions (TJs), we hypothesized that the CaSR participates in regulating TJ assembly. We first assessed the expression of the CaSR in Madin-Darby canine kidney (MDCK) cells at steady state and following manipulations that modulate TJ assembly. Next, we examined the effects of CaSR agonists and antagonists on TJ assembly. Immunofluorescence studies indicate that endogenous CaSR is located at the basolateral pole of MDCK cells. Stable transfection of human CaSR in MDCK cells further reveals that this protein co-distributes with β-catenin on the basolateral membrane. Switching MDCK cells from low-Ca(2+) medium to medium containing a normal Ca(2+) concentration significantly increases CaSR expression at both the mRNA and protein levels. Exposure of MDCK cells maintained in low-Ca(2+) conditions to the CaSR agonists neomycin, Gd(3+) or R-568 causes the transient relocation of the tight junction components ZO-1 and occludin to sites of cell-cell contact, while inducing no significant changes in the expression of mRNAs encoding junction-associated proteins. Stimulation of CaSR also increases the interaction between ZO-1 and the F-actin-binding protein I-afadin. This effect does not involve activation of the AMP-activated protein kinase. By contrast, CaSR inhibition by NPS-2143 significantly decreases interaction of ZO-1 with I-afadin and reduces deposition of ZO-1 at the cell surface following a Ca(2+) switch from 5 µM to 200 µM [Ca(2+)]e. Pre-exposure of MDCK cells to the cell-permeant Ca(2+) chelator BAPTA-AM, similarly prevents TJ assembly caused by CaSR activation. Finally, stable transfection of MDCK cells with a cDNA encoding a human disease-associated gain-of-function mutant form of the CaSR increases the transepithelial electrical resistance of these cells in comparison to expression of the wild-type human CaSR. These observations suggest that the CaSR participates in regulating TJ assembly.
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Affiliation(s)
- François Jouret
- Department of Cellular and Molecular Physiology, Yale School of Medicine, New Haven, CT 06520, USA
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Lia-Baldini AS, Magdelaine C, Nizou A, Airault C, Salles JP, Moulin P, Delemer B, Aitouares M, Funalot B, Sturtz F, Lienhardt-Roussie A. Two novel mutations of the calcium-sensing receptor gene affecting the same amino acid position lead to opposite phenotypes and reveal the importance of p.N802 on receptor activity. Eur J Endocrinol 2013; 168:K27-34. [PMID: 23169696 DOI: 10.1530/eje-12-0714] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Gain-of-function mutations of the calcium-sensing receptor (CASR) gene have been identified in patients with sporadic or familial autosomal dominant hypocalcemia (ADH). Inactivating mutations of the CASR gene cause familial hypocalciuric hypercalcemia (FHH). Here, we report two novel CASR mutations affecting the same amino acid (p.N802); one causes ADH and the other atypical FHH. PATIENTS AND METHODS The first patient, an 11-year-old girl suffering from hypocalcemia, developed nephrocalcinosis when she was only 5 years old. The second patient is a 30-year-old woman who presented with mild hypercalcemia. PCR amplification of CASR coding exons and direct sequencing of PCR products were used to identify mutations. Site-directed mutagenesis was used to generate mutated CASR cDNAs in an expression plasmid. Using the MAPK assay system and transient transfection of Cos-7 cells with wild-type (WT) and mutated CASR, we studied the responses of these mutated receptors to extracellular Ca(2+) and to the negative allosteric CASR modulator, NPS2143. RESULTS Two heterozygous missense mutations (p.N802I and p.N802S) affecting a residue in the sixth transmembrane domain of CASR were identified. In functional tests, the response of the p.N802S mutant to calcium was typical of an inactivating mutation. However, the p.N802I mutant had 70% of the maximally stimulated WT receptor activity even in the absence of extracellular calcium. This constitutive activity was only partially inhibited by the inhibitor, NPS2143. CONCLUSIONS The asparagine at amino acid position 802 appears to be essential for the activity of the CASR protein and is implicated in the mechanism of CASR signaling.
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Affiliation(s)
- Anne-Sophie Lia-Baldini
- EA 6309 - Maintenance Myélinique et Neuropathies Périphériques, Faculté de Médecine - Biochimie, Université de Limoges, 6ème étage, 2 rue du Dr Marcland, 87025 Limoges, France.
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Guarnieri V, Valentina D'Elia A, Baorda F, Pazienza V, Benegiamo G, Stanziale P, Copetti M, Battista C, Grimaldi F, Damante G, Pellegrini F, D'Agruma L, Zelante L, Carella M, Scillitani A. CASR gene activating mutations in two families with autosomal dominant hypocalcemia. Mol Genet Metab 2012; 107:548-52. [PMID: 22789683 DOI: 10.1016/j.ymgme.2012.06.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Accepted: 06/19/2012] [Indexed: 12/19/2022]
Abstract
BACKGROUND Autosomal dominant hypocalcemia (ADH) is an endocrine disorder caused by activating mutations of the calcium-sensing receptor (CASR) gene which plays a major role in maintaining calcium homeostasis. Biochemical features of ADH are hypocalcemia and hypercalciuria with inappropriately low levels of parathyroid hormone (PTH). We report on two four-generation families affected by ADH. AIM To identify mutations of CASR gene in subjects affected by familial idiopathic hypoparathyroidism. To perform functional assays of identified CASR variants by transient transfection on HEK293 cells. RESULTS We identified two CASR variants (Q681R and P221L): the Q681R variant was novel while the P221L had been previously published. Functional assays on the Q681R variant showed that it did not alter the whole expression nor the correct plasmamembrane localization, but enhanced the signaling function, increasing the sensitivity of the receptor as compared to the WT. CONCLUSIONS We report two activating CASR mutations in two families affected by ADH and the functional assays performed on the novel variant Q681R. Our work enlarged the spectrum of mutations of the CASR and contributed to a better elucidation of the protein function.
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Affiliation(s)
- Vito Guarnieri
- Medical Genetics, IRCCS Casa Sollievo della Sofferenza Hospital, viale Padre Pio, 71013 San Giovanni Rotondo, FG, Italy.
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Nissen PH, Christensen SE, Ladefoged SA, Brixen K, Heickendorff L, Mosekilde L. Identification of rare and frequent variants of the CASR gene by high-resolution melting. Clin Chim Acta 2012; 413:605-11. [DOI: 10.1016/j.cca.2011.12.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 12/02/2011] [Accepted: 12/05/2011] [Indexed: 10/14/2022]
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Raue F, Pichl J, Dörr HG, Schnabel D, Heidemann P, Hammersen G, Jaursch-Hancke C, Santen R, Schöfl C, Wabitsch M, Haag C, Schulze E, Frank-Raue K. Activating mutations in the calcium-sensing receptor: genetic and clinical spectrum in 25 patients with autosomal dominant hypocalcaemia - a German survey. Clin Endocrinol (Oxf) 2011; 75:760-5. [PMID: 21645025 DOI: 10.1111/j.1365-2265.2011.04142.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Autosomal dominant hypocalcaemia or hypoparathyroidism is caused by activating mutations of the calcium-sensing receptor (CaSR). Treatment with calcium and vitamin D often worsens hypercalciuria and nephrocalcinosis, and renal impairment can result. Our aim was to describe the phenotypic variance of this rare disorder in a large series and to evaluate the outcome after long-term treatment. DESIGN Nationwide retrospective collaborative study. PATIENTS We describe 25 patients (14 men and 11 women), 20 belonging to 11 families and five single cases. MEASUREMENTS Activating CaSR mutations and clinical and biochemical findings were evaluated. RESULTS Nine different missense mutations of the CaSR, including one novel variant (M734T), were found. Twelve patients (50%) were symptomatic, 9 (36%) had basal ganglia calcifications and 3 (12%) had nephrocalcinosis. Serum calcium was decreased (1·87 ± 0·13 mm), and PTH was decreased (n = 19) or inappropriately low (n = 4). The occurrence of hypocalcaemic symptoms at diagnosis was related to the degree of hypocalcaemia. The occurrence of features like calcification of basal ganglia or kidney calcification did not correlate with the severity of hypocalcaemia or the age at diagnosis. The most common treatment was calcitriol (median dosage 0·6 μg/day), and the mean duration of therapy was 7·1 years (max. 26 years). Hypercalcaemic episodes rarely occurred, and the rate of kidney calcifications was remarkably low (12%). CONCLUSION This series increases the limited knowledge of mutations and phenotypes of this rare disorder. Mutation analysis of the CaSR gene facilitates patient and family management. Low dosages of calcitriol resulted in less frequent renal calcifications.
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Affiliation(s)
- Friedhelm Raue
- Endocrine Practice and Molecular Laboratory, Heidelberg, Germany
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Kim MY, Tan AHK, Ki CS, Lee JI, Jang HW, Shin HW, Kim SW, Min YK, Lee MS, Lee MK, Kim KW, Chung JH. Autosomal dominant hypocalcemia caused by an activating mutation of the calcium-sensing receptor gene: the first case report in Korea. J Korean Med Sci 2010; 25:317-20. [PMID: 20119591 PMCID: PMC2811305 DOI: 10.3346/jkms.2010.25.2.317] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Accepted: 10/01/2008] [Indexed: 12/02/2022] Open
Abstract
Hypoparathyroidism is an abnormality of calcium metabolism characterized by low serum levels of parathyroid hormone in spite of hypocalcemia. The causes of hypoparathyroidism are numerous. Activating mutations in the calcium-sensing receptor (CaSR) gene are well-known causes of familial isolated hypoparathyroidism, also known as autosomal dominant hypocalcemia (ADH). Here we describe members of a Korean family with a heterozygous Pro221Leu mutation causing ADH. This case is the first report in Korea.
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Affiliation(s)
- Mi Yeon Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Alice Hyun Kyung Tan
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Chang-Seok Ki
- Department of Laboratory Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Ji In Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hye Won Jang
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Hyun Won Shin
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Sun Wook Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Yong-Ki Min
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Myung-Shik Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Moon-Kyu Lee
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Kwang-Won Kim
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | - Jae Hoon Chung
- Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
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Hendy GN, Guarnieri V, Canaff L. Chapter 3 Calcium-Sensing Receptor and Associated Diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 89:31-95. [DOI: 10.1016/s1877-1173(09)89003-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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10
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Tordoff MG. Gene discovery and the genetic basis of calcium consumption. Physiol Behav 2008; 94:649-59. [PMID: 18499198 PMCID: PMC2574908 DOI: 10.1016/j.physbeh.2008.04.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2008] [Accepted: 04/02/2008] [Indexed: 10/22/2022]
Abstract
This review makes the case that gene discovery is a worthwhile approach to the study of ingestive behavior in general and to calcium appetite in particular. A description of the methods used to discover genes is provided for non-geneticists. Areas covered include the characterization of an appropriate phenotype, the choice of suitable mouse strains, the generation of a hybrid cross, interval mapping, congenic strain production, and candidate gene analysis. The approach is illustrated with an example involving mice of the C57BL/6J and PWK/PhJ strains, which differ in avidity for calcium solutions. The variation between the strains can be attributed to at least seven quantitative trait loci (QTLs). One of these QTLs is most likely accounted for by Tas1r3, which is a gene involved in the detection of sweet and umami tastes. The discovery of a novel function for a gene with no previously known role in calcium consumption illustrates the power of gene discovery methods to uncover novel mechanisms.
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Affiliation(s)
- Michael G Tordoff
- Monell Chemical Senses Center, 3500 Market St., Philadelphia, PA 19104, USA.
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Hu J, Spiegel AM. Structure and function of the human calcium-sensing receptor: insights from natural and engineered mutations and allosteric modulators. J Cell Mol Med 2008; 11:908-22. [PMID: 17979873 PMCID: PMC4401263 DOI: 10.1111/j.1582-4934.2007.00096.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The human extracellular Ca(2+)-sensing receptor (CaR), a member of the G protein-coupled receptor family 3, plays a key role in the regulation of extracellular calcium homeostasis. It is one of just a few G protein-coupled receptors with a large number of naturally occurring mutations identified in patients. In contrast to the small sizes of its agonists, this large dimeric receptor consists of domains with topologically distinctive orthosteric and allosteric sites. Information derived from studies of naturally occurring mutations, engineered mutations, allosteric modulators and crystal structures of the agonist-binding domain of homologous type 1 metabotropic glutamate receptor and G protein-coupled rhodopsin offers new insights into the structure and function of the CaR.
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Affiliation(s)
- Jianxin Hu
- Molecular Signalling Section, Laboratory of Bioorganic Chemistry, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
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12
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Nissen PH, Christensen SE, Heickendorff L, Brixen K, Mosekilde L. Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population. J Clin Endocrinol Metab 2007; 92:4373-9. [PMID: 17698911 DOI: 10.1210/jc.2007-0322] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CONTEXT The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS A total of 213 subjects clinically suspected to have FHH, and 121 subjects enrolled as part of a family-screening program were studied. Genotype-phenotype relationships were established in 66 mutation-positive index patients and family members. MAIN OUTCOME MEASURES We determined CASR gene mutations, and correlating levels of plasma calcium (albumin corrected), ionized calcium (pH 7.4), and PTH were measured. RESULTS We identified 22 different mutations in 39 FHH families. We evaluated data on circulating calcium and PTH for 11 different mutations, representing a spectrum of clinical phenotypes, ranging from calcium concentrations moderately above the upper reference limit, to calcium levels more than 20% above the upper reference limit. Furthermore, the mean plasma PTH concentration was within the normal range in eight of 11 studied mutations, but mild to moderately elevated in families with the mutations p.C582Y, p.C582F, and p.G553R. CONCLUSIONS The present data add 19 novel mutations to the catalog of inactivating CASR mutations and illustrate a variety of biochemical phenotypes in patients with the molecular genetic diagnosis FHH.
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Affiliation(s)
- Peter H Nissen
- Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus Sygehus, Tage Hansens gade 2, DK-8000 Aarhus C, Denmark.
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13
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de Francisco ALM. Medical therapy of secondary hyperparathyroidism in chronic kidney disease: old and new drugs. Expert Opin Pharmacother 2006; 7:2215-24. [PMID: 17059378 DOI: 10.1517/14656566.7.16.2215] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Secondary hyperparathyroidism (SHPT), a common complication of chronic kidney disease, is characterised by elevated serum levels of parathyroid hormone, parathyroid hyperplasia, excessive bone resorption and increased risk for cardiovascular morbidity. The stringent metabolic targets proposed by the National Kidney Foundation Kidney Disease Outcomes Quality Initiative (K/DOQI) for patients with SHPT are difficult to achieve using conventional treatment regimens. Several new agents, including new vitamin D sterols and phosphate binders, as well as a novel class of compounds--the calcimimetics--have been developed in recent years. This review examines new and traditional therapies for SHPT and how these can best be utilised in order to achieve the new K/DOQI targets.
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Affiliation(s)
- Angel L M de Francisco
- Hospital Universitario Valdecilla, Servicio de Nefrologia, Santander, Spain. martinal@unican
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14
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Burren CP, Curley A, Christie P, Rodda CP, Thakker RV. A family with autosomal dominant hypocalcaemia with hypercalciuria (ADHH): mutational analysis, phenotypic variability and treatment challenges. J Pediatr Endocrinol Metab 2005; 18:689-99. [PMID: 16128246 DOI: 10.1515/jpem.2005.18.7.689] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Autosomal dominant hypocalcaemia with hypercalciuria (ADHH) is an intriguing syndrome, in which activating mutations of the calcium sensing receptor (CaSR) have recently been recognised. We describe a kindred with seven affected individuals across three generations, including patients affected in the first decade of life. Age at diagnosis varied from birth to 50 years. Affected members had hypocalcaemia (1.53-1.85 mmol/l), hypercalciuria, low but detectable parathyroid hormone (PTH) and hypomagnesaemia. Four of seven affected individuals were symptomatic (seizures, abdominal pains and paraesthesias), unrelated to severity of hypocalcaemia. Additional complications include nephrocalcinosis (n = 3) and basal ganglia calcification, identified by CT scanning in all five individuals. Symptomatic individuals were treated with calcium and calcitriol to reduce the risk of hypocalcaemic seizures. DNA sequence analysis, identified a mutation in exon 3, codon 129 (TGC-->TAC) of the CaSR gene of seven affected family members, resulting in loss of a conserved cysteine residue, potentially disrupting CaSR receptor dimerisation. Thus, a novel mutation was identified in this family, who demonstrate variability of ADHH phenotype and also illustrate the complexities of clinical management. Optimal management of ADHH is difficult and we recommend judicious treatment to avoid an increased risk of nephrocalcinosis.
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Affiliation(s)
- C P Burren
- Department of Paediatric Endocrinology, Bristol Royal Hospital for Children, United Bristol Healthcare NHS Trust, Bristol, Avon, UK.
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15
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Peters U, Chatterjee N, Yeager M, Chanock SJ, Schoen RE, McGlynn KA, Church TR, Weissfeld JL, Schatzkin A, Hayes RB. Association of Genetic Variants in the Calcium-Sensing Receptor with Risk of Colorectal Adenoma. Cancer Epidemiol Biomarkers Prev 2004. [DOI: 10.1158/1055-9965.2181.13.12] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Objective: Evidence suggests that calcium prevents colorectal cancer, possibly mediated through the calcium-sensing receptor (CASR). We assessed the associations between CASR gene variants and risk for colorectal adenoma, a cancer precursor. We further investigated gene-diet interactions between the CASR variants and calcium intake on adenoma risk.
Methods: Individuals with advanced distal adenomas (n = 716) and controls with a negative sigmoidoscopy exam (n = 729) were randomly selected from participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Three nonsynonymous variants in the intracellular signaling region of CASR (A986S, R990G, Q1011E) were analyzed by Taqman.
Results: Compared with the most common diplotype (haplotype pair), the odds ratios for advanced adenoma were 0.80 [95% confidence interval (CI), 0.60-1.06], 0.79 (95% CI, 0.55-1.13), and 0.56 (95% CI, 0.36-0.88) for the other three common diplotypes (>5% frequency). Although calcium intake was inversely associated with adenoma risk, CASR diplotypes did not modify this association. However, the power to investigate interactions was limited.
Conclusion: Variants in the CASR intracellular signaling region were significantly associated with the risk of advanced adenoma.
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Affiliation(s)
- Ulrike Peters
- 1Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, Maryland
- 2Cancer Prevention Research Program, Fred Hutchinson Cancer Research Center, Seattle, Washington
- 3Department of Epidemiology, University of Washington, Seattle, Washington
| | - Nilanjan Chatterjee
- 1Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, Maryland
| | - Meredith Yeager
- 4Department of Health and Human Services, Core Genotype Facility, National Cancer Institute, NIH, Gaithersburg, Maryland
| | - Stephen J. Chanock
- 4Department of Health and Human Services, Core Genotype Facility, National Cancer Institute, NIH, Gaithersburg, Maryland
| | | | - Katherine A. McGlynn
- 1Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, Maryland
| | - Timothy R. Church
- 6Division of Environmental and Occupational Health, University of Minnesota, Minneapolis, Minnesota
| | | | - Arthur Schatzkin
- 1Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, Maryland
| | - Richard B. Hayes
- 1Department of Health and Human Services, Division of Cancer Epidemiology and Genetics, National Cancer Institute, NIH, Rockville, Maryland
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Chikatsu N, Watanabe S, Takeuchi Y, Muraosa Y, Sasaki S, Oka Y, Fukumoto S, Fujita T. A family of autosomal dominant hypocalcemia with an activating mutation of calcium-sensing receptor gene. Endocr J 2003; 50:91-6. [PMID: 12733714 DOI: 10.1507/endocrj.50.91] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Autosomal dominant hypocalcemia (ADH) caused by activating mutations of calcium-sensing receptor (CaSR) is characterized by hypocalcemia with inappropriately low concentration of PTH and relative hypercalciuria. Active vitamin D treatment often leads to nephrolithiasis and renal impairment in patients with ADH. However, differential diagnosis between ADH and idiopathic hypoparathyroidism is sometimes very difficult. Here, we report a mutation of CaSR and its functional property found in three generations of a Japanese family. The proband developed seizures at 7 days of age. His mother and elder sister were discovered to have hypoparathyroidism by family survey, but his father was normocalcemic. His grandfather developed heart failure and was found to have hypoparathyroidism. All affected members had been treated with active vitamin D3 and bilateral nephrolithiasis were detected in three of them. DNA sequencing revealed that all affected patients had a heterozygous mutation in CaSR gene that causes proline to leucine substitution at codon 221 (P221L). In vitro functional analysis of the mutant CaSR by measuring inositol 1,4,5-trisphosphate production in response to changes of extracellular Ca indicated that this mutation is an activating one and responsible for ADH in this family. Therefore, careful monitoring of urinary Ca excretion before and during treatment of PTH-deficient hypoparathyroidism is very important, and screening of CaSR mutation should be considered in patients with relative hypercalciuria or with a family history of hypocalcemia.
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Affiliation(s)
- Noriko Chikatsu
- Department of Internal Medicine and Pediatrics, Hitachi General Hospital, Jyonancho, Hitachi 317-0077, Japan
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Conley YP, Finegold DN. Exploring calcium level disorders. Looking through the genetic window for new treatment clues. AWHONN LIFELINES 2002; 6:424-9. [PMID: 12420385 DOI: 10.1177/1091592302238928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Yvette P Conley
- Department of Health Promotion and Development, School of Nursing, Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
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