calcium sensing receptor
Last updated 23 Jan 2026
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The CASR gene provides instructions for making a protein called the calcium-sensing receptor (CaSR). Calcium molecules bind to CaSR, which allows this protein to monitor and regulate the amount of calcium in the blood.
Normal function
The CASR gene provides instructions for making a protein called the calcium-sensing receptor (CaSR). Calcium molecules bind to CaSR, which allows this protein to monitor and regulate the amount of calcium in the blood.
The CaSR protein is found in cells of the parathyroid glands. The four parathyroid glands are located in the neck. These glands produce and release a hormone called parathyroid hormone, which regulates the levels of calcium in the blood. When blood calcium levels are high, calcium binds to CaSR in the parathyroid glands and blocks the production of parathyroid hormone. Without parathyroid hormone, calcium is not released into the blood. CaSR signaling also blocks the growth and division (proliferation) of the cells that make up the parathyroid glands.
The CaSR protein is also found in kidney cells. Kidneys filter fluid and waste products in the body and can reabsorb needed nutrients and release them back into the blood. When calcium binds to CaSR in kidney cells, it blocks the reabsorption of calcium and allows it to be released in the urine.
Conditions referring to this gene or chromosome
Other names
calcium-sensing receptor
CAR
extracellular calcium-sensing receptor
GPRC2A
parathyroid Ca(2+)-sensing receptor 1
parathyroid cell calcium-sensing receptor
PCAR1
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Further reading and references
- calcium sensing receptor; MedlinePlus, National Library of Medicine.
- Cetani F, Pardi E, Aretini P, Saponaro F, Borsari S, Mazoni L, Apicella M, Civita P, La Ferla M, Caligo MA, Lessi F, Mazzanti CM, Torregossa L, Oppo A, Marcocci C. Whole exome sequencing in familial isolated primary hyperparathyroidism. J Endocrinol Invest. 2020 Feb;43(2):231-245. doi: 10.1007/s40618-019-01107-5. Epub 2019 Sep 5.
- Charoenngam N, Wattanachayakul P, Mannstadt M. CASRdb: A Publicly Accessible Comprehensive Database for Disease-Associated Calcium-Sensing Receptor Variants. J Clin Endocrinol Metab. 2025 Jan 21;110(2):297-302. doi: 10.1210/clinem/dgae769.
- English KA, Lines KE, Thakker RV. Genetics of hereditary forms of primary hyperparathyroidism. Hormones (Athens). 2024 Mar;23(1):3-14. doi: 10.1007/s42000-023-00508-9. Epub 2023 Dec 1.
- Hannan FM, Nesbit MA, Christie PT, Lissens W, Van der Schueren B, Bex M, Bouillon R, Thakker RV. A homozygous inactivating calcium-sensing receptor mutation, Pro339Thr, is associated with isolated primary hyperparathyroidism: correlation between location of mutations and severity of hypercalcaemia. Clin Endocrinol (Oxf). 2010 Dec;73(6):715-22. doi: 10.1111/j.1365-2265.2010.03870.x.
- Hendy GN, Guarnieri V, Canaff L. Calcium-sensing receptor and associated diseases. Prog Mol Biol Transl Sci. 2009;89:31-95. doi: 10.1016/S1877-1173(09)89003-0. Epub 2009 Oct 7.
- Kinoshita Y, Hori M, Taguchi M, Watanabe S, Fukumoto S. Functional activities of mutant calcium-sensing receptors determine clinical presentations in patients with autosomal dominant hypocalcemia. J Clin Endocrinol Metab. 2014 Feb;99(2):E363-8. doi: 10.1210/jc.2013-3430. Epub 2013 Dec 2.
- Ranieri M, Tamma G, Di Mise A, Vezzoli G, Soldati L, Svelto M, Valenti G. Excessive signal transduction of gain-of-function variants of the calcium-sensing receptor (CaSR) are associated with increased ER to cytosol calcium gradient. PLoS One. 2013 Nov 14;8(11):e79113. doi: 10.1371/journal.pone.0079113. eCollection 2013.
- Raue F, Pichl J, Dorr HG, Schnabel D, Heidemann P, Hammersen G, Jaursch-Hancke C, Santen R, Schofl 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 Dec;75(6):760-5. doi: 10.1111/j.1365-2265.2011.04142.x.
- Thim SB, Birkebaek NH, Nissen PH, Host C. Activating calcium-sensing receptor gene variants in children: a case study of infant hypocalcaemia and literature review. Acta Paediatr. 2014 Nov;103(11):1117-25. doi: 10.1111/apa.12743. Epub 2014 Aug 24.
- Warner J, Epstein M, Sweet A, Singh D, Burgess J, Stranks S, Hill P, Perry-Keene D, Learoyd D, Robinson B, Birdsey P, Mackenzie E, Teh BT, Prins JB, Cardinal J. Genetic testing in familial isolated hyperparathyroidism: unexpected results and their implications. J Med Genet. 2004 Mar;41(3):155-60. doi: 10.1136/jmg.2003.016725.
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