scholarly journals Hipocalcemia Crónica por Anticorpos Anti-Recetor do Cálcio

2014 ◽  
Vol 27 (3) ◽  
pp. 399
Author(s):  
Pedro Marques ◽  
Rita Santos ◽  
Branca Cavaco ◽  
Valeriano Leite
Keyword(s):  
Parathyroid Hormone ◽  
Genetic Disorder ◽  
Neck Surgery ◽  
Urinary Calcium ◽  
Clinical Report ◽  
Calcium Sensing Receptor ◽  
Casr Gene ◽  
Calcium Sensing ◽  
Calcium Phosphorus ◽  
Receptor Antibodies

<strong>Introduction:</strong> Hypoparathyroidism is an entity associated with hypocalcemia, more frequently a consequence of neck surgery. An autoimmune etiology is rare and its diagnosis difficult to establish.<br /><strong>Clinical report:</strong> 52 year-old woman, with irrelevant past medical history and no significant familial conditions, referred because of hypocalcemia and basal ganglia calcifications, detected in the course of investigation of myalgias. Besides hypocalcemia (4.6 mg/ dL), hyperphosphatemia (8.7 mg/dL), undetectable parathyroid hormone and low urinary calcium, phosphorus and magnesium were present. Molecular analysis of CaSR gene excluded germinal mutations. Anti-calcium sensing receptor antibodies (anti-CaSR) were present. The patient is asymptomatic and normocalcemic under treatment with calcium and vitamin D.<br /><strong>Discussion:</strong> Although rare, hypocalcemia due to anti-CaSR hypoparathyroidism must be considered in the absence of previous neck surgery, hypocalcemic drugs, familial history or phenotype suggesting a genetic disorder. Low or undetectable parathyroid hormone excludes pseudohypoparathyroidism and anti-CaSR positivity establishes the diagnosis.<br /><strong>Keywords:</strong> Hypocalcemia; Hypoparathyroidism; Autoantibodies; Receptors, Calcium-Sensing.

scholarly journals A Novel Variant in the Calcium-Sensing Receptor Associated with Familial Hypocalciuric Hypercalcemia and Low-to-Normal PTH

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Sachin K. Majumdar ◽  
Tess Jacob ◽  
Allen Bale ◽  
Allison Bailey ◽  
Jeffrey Kwon ◽  
...  
Keyword(s):  
Serum Calcium ◽  
Urinary Calcium ◽  
Urinary Calcium Excretion ◽  
Calcium Excretion ◽  
Familial Hypocalciuric Hypercalcemia ◽  
Calcium Sensing Receptor ◽  
Benign Condition ◽  
Casr Gene ◽  
Calcium Sensing ◽  
Novel Variant

Familial hypocalciuric hypercalcemia (FHH) is considered a relatively benign condition characterized by mild elevations in serum calcium and relatively low urinary calcium excretion. It results from an elevated set point in serum calcium arising from variants in the calcium-sensing receptor (CaSR) gene but also AP2S1 and GNA11 genes, which encode for adaptor-related protein complex 2 and G11 proteins, respectively. The manifestations of FHH can vary and sometimes overlap with primary hyperparathyroidism making the diagnosis challenging. Case Presentations. We report a mother and daughter with a novel heterozygous variant in the CaSR gene resulting in a serine to leucine substitution at position 147 (S147L) of the CaSR. Both patients had mild hypercalcemia, relatively low urinary calcium excretion, elevated calcitriol, and low-to-normal intact PTH. The proband (daughter) presented with symptoms associated with hypercalcemia and was incidentally found to have a bony lesion suspicious for osteitis fibrosa cystica, and she was also diagnosed with sarcoidosis. Subtotal parathyroidectomy revealed normal-weight parathyroid glands comprised of 50–80% parathyroid epithelial cells, which has been documented as within the spectrum of normal. Her mother had no symptoms, and no intervention was pursued. Conclusion. We report a novel variant in the CaSR associated with FHH in two patients with similar biochemical features yet differing clinical manifestations. While the relationship of the bony findings and parathyroid histology with this variant remains unclear, these cases enrich our knowledge of CaSR physiology and provide further examples of how varied the manifestations of FHH can be.

scholarly journals Calcium-Sensing Receptor and Regulation of WNK Kinases in the Kidney

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1644
Author(s):  
Daria S. Ostroverkhova ◽  
Junda Hu ◽  
Vadim V. Tarasov ◽  
Tatiana I. Melnikova ◽  
Yuri B. Porozov ◽  
...  
Keyword(s):  
Urinary Calcium ◽  
Calcium Handling ◽  
Transport Systems ◽  
Calcium Excretion ◽  
Loss Of Function ◽  
Distal Nephron ◽  
Calcium Sensing Receptor ◽  
Gain Of Function ◽  
Casr Gene ◽  
Calcium Sensing

The kidney is essential for systemic calcium homeostasis. Urinary calcium excretion can be viewed as an integrative renal response to endocrine and local stimuli. The extracellular calcium-sensing receptor (CaSR) elicits a number of adaptive reactions to increased plasma Ca2+ levels including the control of parathyroid hormone release and regulation of the renal calcium handling. Calcium reabsorption in the distal nephron of the kidney is functionally coupled to sodium transport. Apart from Ca2+ transport systems, CaSR signaling affects relevant distal Na+-(K+)-2Cl− cotransporters, NKCC2 and NCC. NKCC2 and NCC are activated by a kinase cascade comprising with-no-lysine [K] kinases (WNKs) and two homologous Ste20-related kinases, SPAK and OSR1. Gain-of-function mutations within the WNK-SPAK/OSR1-NKCC2/NCC pathway lead to renal salt retention and hypertension, whereas loss-of-function mutations have been associated with salt-losing tubulopathies such as Bartter or Gitelman syndromes. A Bartter-like syndrome has been also described in patients carrying gain-of-function mutations in the CaSR gene. Recent work suggested that CaSR signals via the WNK-SPAK/OSR1 cascade to modulate salt reabsorption along the distal nephron. The review presented here summarizes the latest progress in understanding of functional interactions between CaSR and WNKs and their potential impact on the renal salt handling and blood pressure.

scholarly journals Relationship between parathyroid calcium-sensing receptor expression and potency of the calcimimetic, cinacalcet, in suppressing parathyroid hormone secretion in an in vivo murine model of primary hyperparathyroidism

2005 ◽  
Vol 153 (4) ◽  
pp. 587-594 ◽  
Author(s):  
Takehisa Kawata ◽  
Yasuo Imanishi ◽  
Keisuke Kobayashi ◽  
Takao Kenko ◽  
Michihito Wada ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Secondary Hyperparathyroidism ◽  
Murine Model ◽  
Hormone Secretion ◽  
Suppressive Effect ◽  
Receptor Expression ◽  
Parathyroid Glands ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing

Cinacalcet HCl, an allosteric modulator of the calcium-sensing receptor (CaR), has recently been approved for the treatment of secondary hyperparathyroidism in patients with chronic kidney disease on dialysis, due to its suppressive effect on parathyroid hormone (PTH) secretion. Although cinacalcet’s effects in patients with primary and secondary hyperparathyroidism have been reported, the crucial relationship between the effect of calcimimetics and CaR expression on the parathyroid glands requires better understanding. To investigate its suppressive effect on PTH secretion in primary hyperparathyroidism, in which hypercalcemia may already have stimulated considerable CaR activity, we investigated the effect of cinacalcet HCl on PTH-cyclin D1 transgenic mice (PC2 mice), a model of primary hyperparathyroidism with hypo-expression of CaR on their parathyroid glands. A single administration of 30 mg/kg body weight (BW) of cinacalcet HCl significantly suppressed serum calcium (Ca) levels 2 h after administration in 65- to 85-week-old PC2 mice with chronic biochemical hyperparathyroidism. The percentage reduction in serum PTH was significantly correlated with CaR hypo-expression in the parathyroid glands. In older PC2 mice (93–99 weeks old) with advanced hyperparathyroidism, serum Ca and PTH levels were not suppressed by 30 mg cinacalcet HCl/kg. However, serum Ca and PTH levels were significantly suppressed by 100 mg/kg of cinacalcet HCl, suggesting that higher doses of this compound could overcome severe hyperparathyroidism. To conclude, cinacalcet HCl demonstrated potency in a murine model of primary hyperparathyroidism in spite of any presumed endogenous CaR activation by hypercalcemia and hypo-expression of CaR in the parathyroid glands.

Thick ascending limb claudins are altered to increase calciuria and magnesiuria in metabolic acidosis

2021 ◽  
Author(s):  
Il Hwan Oh ◽  
Chor Ho Jo ◽  
Sua Kim ◽  
Sungsin Jo ◽  
Sungjin Chung ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Immunofluorescence Microscopy ◽  
Urinary Calcium ◽  
Receptor Protein ◽  
Thick Ascending Limb ◽  
Sprague Dawley ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing ◽  
Sprague Dawley Rats ◽  
Calcium And Magnesium

Urinary calcium and magnesium wasting is a characteristic feature of metabolic acidosis, and this study focused on the role of the thick ascending limb of Henle's loop in metabolic acidosis-induced hypercalciuria and hypermagnesiuria because thick ascending limb is an important site of paracellular calcium and magnesium reabsorption. Male Sprague-Dawley rats were used to determine the effects of acid loading (by adding NH4Cl 7.2 mmol/220 g BW/d to food slurry for 7 days) on renal expression of claudins and then to evaluate whether the results were reversed by antagonizing calcium-sensing receptor (using NPS-2143). At the end of each animal experiment, the kidneys were harvested for immunoblotting, immunofluorescence microscopy and qPCR analysis of claudins and the calcium-sensing receptor. As expected, NH4Cl loading lowered urinary pH and increased excretion of urinary calcium and magnesium. In NH4Cl-loaded rats, renal protein and mRNA expression of claudin-16, and claudin-19 decreased compared with controls. However, claudin-14 protein and mRNA increased in NH4Cl-loaded rats. Consistently, the calcium-sensing receptor protein and mRNA were upregulated in NH4Cl-loaded rats. All these changes were reversed by NPS-2143 coadministration and were confirmed using immunofluorescence microscopy. Hypercalciuria and hypermagnesiuria in NH4Cl-loaded rats were significantly ameliorated by NPS-2143 coadministration as well. We conclude that in metabolic acidosis, claudin-16 and claudin-19 in the thick ascending limb are downregulated to produce hypercalciuria and hypermagnesiuria via the calcium-sensing receptor.

Identification of a novel calcium-sensing receptor (CASR) gene mutation in a patient with familial hypocalciuric hypercalcemia

2019 ◽  
Vol 493 ◽  
pp. S229
Author(s):  
M. Ortiz Espejo ◽  
R. Batanero Maguregui ◽  
C. Montalban Carrasco ◽  
L. Ramos Ramos ◽  
R. García Sardina ◽  
...  
Keyword(s):  
Gene Mutation ◽  
Familial Hypocalciuric Hypercalcemia ◽  
Calcium Sensing Receptor ◽  
Casr Gene ◽  
Calcium Sensing

Neonatal Severe Hyperparathyroidism due to Compound Heterozygous Mutation of Calcium Sensing Receptor (CaSR) Gene Presenting as Encephalopathy

2014 ◽  
Vol 81 (11) ◽  
pp. 1228-1229 ◽  
Author(s):  
Abhishek Kulkarni ◽  
Mahesh Mohite ◽  
Ramaa Vijaykumar ◽  
Prasanna Bansode ◽  
Sachin Murade ◽  
...  
Keyword(s):  
Compound Heterozygous Mutation ◽  
Heterozygous Mutation ◽  
Compound Heterozygous ◽  
Calcium Sensing Receptor ◽  
Casr Gene ◽  
Calcium Sensing

scholarly journals Identification and Functional Characterization of a Novel Mutation in the Calcium-Sensing Receptor Gene in Familial Hypocalciuric Hypercalcemia: Modulation of Clinical Severity by Vitamin D Status

2007 ◽  
Vol 92 (7) ◽  
pp. 2616-2623 ◽  
Author(s):  
Katerina Zajickova ◽  
Jana Vrbikova ◽  
Lucie Canaff ◽  
Peter D. Pawelek ◽  
David Goltzman ◽  
...  
Keyword(s):  
Vitamin D ◽  
Gene Mutation ◽  
Clinical Severity ◽  
Vitamin D Status ◽  
Familial Hypocalciuric Hypercalcemia ◽  
Calcium Sensing Receptor ◽  
Benign Condition ◽  
Casr Gene ◽  
Calcium Sensing ◽  
Serum Pth

Abstract Context: Familial hypocalciuric hypercalcemia (FHH) is a benign condition associated with heterogeneous inactivating mutations in the calcium-sensing receptor (CASR) gene. Objective: The objective of the study was to identify and characterize a CASR mutation in a moderately hypercalcemic, hyperparathyroid individual and his family and assess the influence of vitamin D status on the clinical expression of the defect. Subjects: We studied a kindred with FHH, in which the proband (a 34-yr-old male) was initially diagnosed with primary hyperparathyroidism due to frankly elevated serum PTH levels. Methods: CASR gene mutation analysis was performed on genomic DNA of the proband and family members. The mutant CASR was functionally characterized by transient transfection studies in kidney cells in vitro. Results: A novel heterozygous mutation (F180C, TTC&gt;TGC) in exon 4 of the CASR gene was identified. Although the mutant receptor was expressed normally at the cell surface, it was unresponsive with respect to intracellular signaling (MAPK activation) to increases in extracellular calcium concentrations. The baby daughter of the proband presented with neonatal hyperparathyroidism with markedly elevated PTH. Vitamin D supplementation of both the proband and the baby resulted in reduction of serum PTH levels to the normal range. The serum calcium level remained at a constant and moderately elevated level. Conclusion: The identification of a novel CASR gene mutation established the basis of the hypercalcemia in the kindred. Concomitant vitamin D deficiency modulates the severity of the presentation of FHH.

Sign in / Sign up

Export Citation Format

Share Document