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URL of this page: https://medlineplus.gov/genetics/gene/fgf23/

FGF23 gene

fibroblast growth factor 23

Normal Function

The FGF23 gene provides instructions for making a protein called fibroblast growth factor 23, which is produced in bone cells. This protein helps regulate phosphate levels within the body. Among its many functions, phosphate plays a critical role in the formation and growth of bones during childhood and helps maintain bone strength in adults.

Fibroblast growth factor 23 works in the kidneys to keep the body's phosphate levels in balance. The kidneys normally release excess phosphate in the urine, and they reabsorb this mineral into the bloodstream when more is needed. Fibroblast growth factor 23 acts as a signal that tells the kidneys to stop reabsorbing phosphate into the bloodstream.

In order for fibroblast growth factor 23 to function, sugar molecules must attach to the protein through a process called glycosylation. This allows fibroblast growth factor 23 to move out of the bone cell and protects it from being broken down. Once outside the cell, fibroblast growth factor 23 must bind to a receptor protein that spans the membrane of kidney cells. Binding to this receptor triggers a signaling pathway that stops phosphate reabsorption by the kidneys. When more phosphate is needed, fibroblast growth factor 23 is cut (cleaved) at a certain site, which turns off (inactivates) the protein. This helps regulate the amount of active fibroblast growth factor 23 that is circulating in the bloodstream.

Health Conditions Related to Genetic Changes

Hyperphosphatemic familial tumoral calcinosis

Variants (also called mutations) in the FGF23 gene have been found to cause hyperphosphatemic familial tumoral calcinosis (HFTC), a condition that is characterized by increased levels of phosphate in the blood (hyperphosphatemia) and abnormal deposits of phosphate and calcium (calcinosis) in the body's tissues. Variants in the FGF23 gene can cause cells to produce a version of the protein that does not function properly. This altered protein is quickly broken down in cells, leading to a shortage of available fibroblast growth factor 23. This protein shortage decreases signaling and increases the amount of phosphate that is reabsorbed by the kidneys. The excess phosphate can combine with calcium to form deposits that build up in the tissues, leading to the calcinosis seen in people with HFTC.

More About This Health Condition

Kidney stones

MedlinePlus Genetics provides information about Kidney stones

More About This Health Condition

Other disorders

Variants in the FGF23 gene are a rare cause of hypophosphatemic rickets. This condition is characterized by low levels of phosphate in the blood (hypophosphatemia). A lack of phosphate can cause weakening or softening of the bones (rickets). The variants in the FGF23 gene that are associated with hypophosphatemic rickets cause cells to produce a version of the protein that is not cleaved. This increases the amount of activated FGF23 protein in the blood and impairs the reabsorption of phosphate by the kidneys. This means less phosphate is available for normal bone development and maintenance, which contributes to the skeletal abnormalities seen in people with hypophosphatemic rickets.

Other Names for This Gene

Additional Information & Resources

Tests Listed in the Genetic Testing Registry

Scientific Articles on PubMed

Catalog of Genes and Diseases from OMIM

Gene and Variant Databases

References

  • ADHR Consortium. Autosomal dominant hypophosphataemic rickets is associated with mutations in FGF23. Nat Genet. 2000 Nov;26(3):345-8. doi: 10.1038/81664. Citation on PubMed
  • Bergwitz C, Juppner H. Regulation of phosphate homeostasis by PTH, vitamin D, and FGF23. Annu Rev Med. 2010;61:91-104. doi: 10.1146/annurev.med.051308.111339. Citation on PubMed or Free article on PubMed Central
  • Courbebaisse M, Lanske B. Biology of Fibroblast Growth Factor 23: From Physiology to Pathology. Cold Spring Harb Perspect Med. 2018 May 1;8(5):a031260. doi: 10.1101/cshperspect.a031260. Citation on PubMed
  • Farrow EG, Imel EA, White KE. Miscellaneous non-inflammatory musculoskeletal conditions. Hyperphosphatemic familial tumoral calcinosis (FGF23, GALNT3 and alphaKlotho). Best Pract Res Clin Rheumatol. 2011 Oct;25(5):735-47. doi: 10.1016/j.berh.2011.10.020. Citation on PubMed or Free article on PubMed Central
  • Fukumoto S. Physiological regulation and disorders of phosphate metabolism--pivotal role of fibroblast growth factor 23. Intern Med. 2008;47(5):337-43. doi: 10.2169/internalmedicine.47.0730. Epub 2008 Mar 3. Citation on PubMed
  • Garringer HJ, Malekpour M, Esteghamat F, Mortazavi SM, Davis SI, Farrow EG, Yu X, Arking DE, Dietz HC, White KE. Molecular genetic and biochemical analyses of FGF23 mutations in familial tumoral calcinosis. Am J Physiol Endocrinol Metab. 2008 Oct;295(4):E929-37. doi: 10.1152/ajpendo.90456.2008. Epub 2008 Aug 5. Citation on PubMed or Free article on PubMed Central
  • Imel EA, Econs MJ. Fibroblast growth factor 23: roles in health and disease. J Am Soc Nephrol. 2005 Sep;16(9):2565-75. doi: 10.1681/ASN.2005050573. Epub 2005 Jul 20. No abstract available. Citation on PubMed
  • Quarles LD. FGF23, PHEX, and MEPE regulation of phosphate homeostasis and skeletal mineralization. Am J Physiol Endocrinol Metab. 2003 Jul;285(1):E1-9. doi: 10.1152/ajpendo.00016.2003. Citation on PubMed
  • Ramon I, Kleynen P, Body JJ, Karmali R. Fibroblast growth factor 23 and its role in phosphate homeostasis. Eur J Endocrinol. 2010 Jan;162(1):1-10. doi: 10.1530/EJE-09-0597. Epub 2009 Sep 23. Citation on PubMed
  • Razzaque MS. The FGF23-Klotho axis: endocrine regulation of phosphate homeostasis. Nat Rev Endocrinol. 2009 Nov;5(11):611-9. doi: 10.1038/nrendo.2009.196. Citation on PubMed or Free article on PubMed Central
  • Saito T, Fukumoto S. Fibroblast Growth Factor 23 (FGF23) and Disorders of Phosphate Metabolism. Int J Pediatr Endocrinol. 2009;2009:496514. doi: 10.1155/2009/496514. Epub 2009 Oct 7. Citation on PubMed or Free article on PubMed Central
  • Sprecher E. Familial tumoral calcinosis: from characterization of a rare phenotype to the pathogenesis of ectopic calcification. J Invest Dermatol. 2010 Mar;130(3):652-60. doi: 10.1038/jid.2009.337. Epub 2009 Oct 29. Citation on PubMed or Free article on PubMed Central

The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.