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Cuny T, Romanet P, Goldsworthy M, Guérin C, Wilkin M, Roche P, Sebag F, van Summeren LE, Stevenson M, Howles SA, Deharo JC, Thakker RV, Taïeb D. Cinacalcet Reverses Short QT Interval in Familial Hypocalciuric Hypercalcemia Type 1. J Clin Endocrinol Metab 2024; 109:549-556. [PMID: 37602721 PMCID: PMC7615553 DOI: 10.1210/clinem/dgad494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 07/17/2023] [Accepted: 08/17/2023] [Indexed: 08/22/2023]
Abstract
CONTEXT Familial hypocalciuric hypercalcemia type 1 (FHH-1) defines an autosomal dominant disease, related to mutations in the CASR gene, with mild hypercalcemia in most cases. Cases of FHH-1 with a short QT interval have not been reported to date. OBJECTIVE Three family members presented with FHH-1 and short QT interval (<360 ms), a condition that could lead to cardiac arrhythmias, and the effects of cinacalcet, an allosteric modulator of the CaSR, in rectifying the abnormal sensitivity of the mutant CaSR and in correcting the short QT interval were determined. METHODS CASR mutational analysis was performed by next-generation sequencing and functional consequences of the identified CaSR variant (p.Ile555Thr), and effects of cinacalcet were assessed in HEK293 cells expressing wild-type and variant CaSRs. A cinacalcet test consisting of administration of 30 mg cinacalcet (8 Am) followed by hourly measurement of serum calcium, phosphate, and parathyroid hormone during 8 hours and an electrocardiogram was performed. RESULTS The CaSR variant (p.Ile555Thr) was confirmed in all 3 FHH-1 patients and was shown to be associated with a loss of function that was ameliorated by cinacalcet. Cinacalcet decreased parathyroid hormone by >50% within two hours, and decreases in serum calcium and increases in serum phosphate occurred within 8 hours, with rectification of the QT interval, which remained normal after 3 months of cinacalcet treatment. CONCLUSION Our results indicate that FHH-1 patients should be assessed for a short QT interval and a cinacalcet test used to select patients who are likely to benefit from this treatment.
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Affiliation(s)
- Thomas Cuny
- Aix Marseille Univ, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, Service d'Endocrinologie, Marseille, France
| | - Pauline Romanet
- Aix Marseille Univ, APHM, Marseille Medical Genetics, Inserm U1251, Hôpital de la Conception, Laboratoire de Biochimie et Biologie moléculaire, Marseille, France
| | | | - Carole Guérin
- Aix Marseille Univ, APHM, Hôpital de la Conception, Service de Chirurgie endocrinienne, Marseille, France
| | - Marie Wilkin
- Aix Marseille Univ, APHM, Hôpital de la Timone, Service de Cardiologie, Marseille France
| | - Philippe Roche
- Integrative Structural & Chemical Biology (iSCB) & HiTS Platform, Cancer Research Centre of Marseille, CNRS UMR7258, Marseille, France
| | - Frédéric Sebag
- Aix Marseille Univ, APHM, Hôpital de la Conception, Service de Chirurgie endocrinienne, Marseille, France
| | - Lynn E van Summeren
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Mark Stevenson
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Sarah A Howles
- Nuffield Department of Surgical Sciences, University of Oxford, United Kingdom
| | - Jean-Claude Deharo
- Aix Marseille Univ, APHM, Hôpital de la Timone, Service de Cardiologie, Marseille France
| | - Rajesh V Thakker
- Academic Endocrine Unit, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
- National Institute for Health Research Oxford Biomedical Research Centre, Oxford, UK
| | - David Taïeb
- Department of Nuclear Medicine, La Timone University Hospital, CERIMED, Aix-Marseille University, France
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Tan RSG, Lee CHL, Dimke H, Todd Alexander R. The role of calcium-sensing receptor signaling in regulating transepithelial calcium transport. Exp Biol Med (Maywood) 2021; 246:2407-2419. [PMID: 33926258 DOI: 10.1177/15353702211010415] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The calcium-sensing receptor (CaSR) plays a critical role in sensing extracellular calcium (Ca2+) and signaling to maintain Ca2+ homeostasis. In the parathyroid, the CaSR regulates secretion of parathyroid hormone, which functions to increase extracellular Ca2+ levels. The CaSR is also located in other organs imperative to Ca2+ homeostasis including the kidney and intestine, where it modulates Ca2+ reabsorption and absorption, respectively. In this review, we describe CaSR expression and its function in transepithelial Ca2+ transport in the kidney and intestine. Activation of the CaSR leads to G protein dependent and independent signaling cascades. The known CaSR signal transduction pathways involved in modulating paracellular and transcellular epithelial Ca2+ transport are discussed. Mutations in the CaSR cause a range of diseases that manifest in altered serum Ca2+ levels. Gain-of-function mutations in the CaSR result in autosomal dominant hypocalcemia type 1, while loss-of-function mutations cause familial hypocalciuric hypercalcemia. Additionally, the putative serine protease, FAM111A, is discussed as a potential regulator of the CaSR because mutations in FAM111A cause Kenny Caffey syndrome type 2, gracile bone dysplasia, and osteocraniostenosis, diseases that are characterized by hypocalcemia, hypoparathyroidism, and bony abnormalities, i.e. share phenotypic features of autosomal dominant hypocalcemia. Recent work has helped to elucidate the effect of CaSR signaling cascades on downstream proteins involved in Ca2+ transport across renal and intestinal epithelia; however, much remains to be discovered.
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Affiliation(s)
- Rebecca Siu Ga Tan
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada
| | | | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense 5000, Denmark.,Department of Nephrology, Odense University Hospital, Odense 5000, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton T6G 1C9, Canada.,Membrane Protein Disease Research Group, University of Alberta, Edmonton T6G 1C9, Canada.,Department of Pediatrics, University of Alberta, Edmonton T6G 1C9, Canada
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