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Familial hypocalciuric hypercalcemia classification

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ajay Gade MD[2]]

Overview

Overview

Familial hypocalciuric hypercalcemia is classified into three types. Type-1 is due to loss-of-function mutations of the calcium-sensing receptor, type-2 is caused by the mutation of GNA 11 gene, type-3 is associated with adaptor-related protein complex 2, sigma 1 subunit (AP2S1) mutations, which alter the endocytosis of calcium-sensing receptor.

Classification

Classification

Classification based on genetic mutations

FHH is an autosomal dominant benign inherited condition caused by three types of mutations the most common mutation is an inactivating missense mutation of the CaSR located on chromosome 3q. It is very rarely caused by the mutation of GNA11 gene and AP2S1 gene.[1][2]

There are three types of FHH:


 
 
 
 
 
 
 
 
 
Familial Hypocalciuric Hypercalcemia
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Type 1 FHH
 
 
Type 2 FHH
 
 
Type 3 FHH
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Mutations of the calcium-sensing receptor
 
 
Mutation in the GNA11 gene
 
 
Mutation in the AP2S1 gene
 
 
 
 
References

References

  1. Stratta P, Merlotti G, Musetti C, Quaglia M, Pagani A, Izzo C, Radin E, Airoldi A, Baorda F, Palladino T, Leone MP, Guarnieri V (2014). “Calcium-sensing-related gene mutations in hypercalcaemic hypocalciuric patients as differential diagnosis from primary hyperparathyroidism: detection of two novel inactivating mutations in an Italian population”. Nephrol. Dial. Transplant. 29 (10): 1902–9. doi:10.1093/ndt/gfu065. PMID 25104082.
  2. Vargas-Poussou R, Mansour-Hendili L, Baron S, Bertocchio JP, Travers C, Simian C, Treard C, Baudouin V, Beltran S, Broux F, Camard O, Cloarec S, Cormier C, Debussche X, Dubosclard E, Eid C, Haymann JP, Kiando SR, Kuhn JM, Lefort G, Linglart A, Lucas-Pouliquen B, Macher MA, Maruani G, Ouzounian S, Polak M, Requeda E, Robier D, Silve C, Souberbielle JC, Tack I, Vezzosi D, Jeunemaitre X, Houillier P (2016). “Familial Hypocalciuric Hypercalcemia Types 1 and 3 and Primary Hyperparathyroidism: Similarities and Differences”. J. Clin. Endocrinol. Metab. 101 (5): 2185–95. doi:10.1210/jc.2015-3442. PMID 26963950.
  3. Gorvin CM, Cranston T, Hannan FM, Rust N, Qureshi A, Nesbit MA, Thakker RV (2016). “A G-protein Subunit-α11 Loss-of-Function Mutation, Thr54Met, Causes Familial Hypocalciuric Hypercalcemia Type 2 (FHH2)”. J. Bone Miner. Res. 31 (6): 1200–6. doi:10.1002/jbmr.2778. PMC 4949650. PMID 26729423.
  4. Nesbit MA, Hannan FM, Howles SA, Babinsky VN, Head RA, Cranston T, Rust N, Hobbs MR, Heath H, Thakker RV (2013). “Mutations affecting G-protein subunit α11 in hypercalcemia and hypocalcemia”. N. Engl. J. Med. 368 (26): 2476–2486. doi:10.1056/NEJMoa1300253. PMC 3773604. PMID 23802516.
  5. Szalat A, Shpitzen S, Tsur A, Zalmon Koren I, Shilo S, Tripto-Shkolnik L, Durst R, Leitersdorf E, Meiner V (2017). “Stepwise CaSR, AP2S1, and GNA11 sequencing in patients with suspected familial hypocalciuric hypercalcemia”. Endocrine. 55 (3): 741–747. doi:10.1007/s12020-017-1241-5. PMID 28176280.
  6. Hendy GN, Canaff L, Newfield RS, Tripto-Shkolnik L, Wong BY, Lee BS, Cole DE (2014). “Codon Arg15 mutations of the AP2S1 gene: common occurrence in familial hypocalciuric hypercalcemia cases negative for calcium-sensing receptor (CASR) mutations”. J. Clin. Endocrinol. Metab. 99 (7): E1311–5. doi:10.1210/jc.2014-1120. PMID 24731014.
  7. Mayr B, Schnabel D, Dörr HG, Schöfl C (2016). “GENETICS IN ENDOCRINOLOGY: Gain and loss of function mutations of the calcium-sensing receptor and associated proteins: current treatment concepts”. Eur. J. Endocrinol. 174 (5): R189–208. doi:10.1530/EJE-15-1028. PMID 26646938.

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