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Genetics Home Reference: your guide to understanding genetic conditions     A service of the U.S. National Library of Medicine®


Reviewed February 2007

What is the official name of the CDH23 gene?

The official name of this gene is “cadherin-related 23.”

CDH23 is the gene's official symbol. The CDH23 gene is also known by other names, listed below.

What is the normal function of the CDH23 gene?

The CDH23 gene provides instructions for making a protein called cadherin 23, a type of protein that helps cells stick together. Different cell types make different versions of this protein, including a short version in the light-sensitive layer in the back of the eye (the retina) and a longer version in the inner ear. Cadherin 23 interacts with other proteins in the cell membrane as part of a protein complex that is involved in cell attachment.

Research suggests that the cadherin 23 protein complex shapes inner ear structures called hair bundles. These structures are made of stereocilia, which are hairlike projections that bend in response to sound waves. This bending motion is critical for converting sound waves to nerve impulses, which is an essential process for normal hearing. The protein complex may organize hair bundles by cross-linking the stereocilia and helping to promote the transmission of sound waves.

In the retina, the role of the cadherin 23 protein complex is less well understood. Its presence in specialized cells that detect light and color (photoreceptor cells) suggests that it plays a critical role in the development and function of these cells.

Does the CDH23 gene share characteristics with other genes?

The CDH23 gene belongs to a family of genes called CDH (cadherins).

A gene family is a group of genes that share important characteristics. Classifying individual genes into families helps researchers describe how genes are related to each other. For more information, see What are gene families? ( in the Handbook.

How are changes in the CDH23 gene related to health conditions?

nonsyndromic deafness - caused by mutations in the CDH23 gene

Approximately 20 mutations in the CDH23 gene have been identified in people with a type of nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body) called DFNB12. Most of these mutations change a single protein building block (amino acid) used to make cadherin 23. These mutations alter, but do not totally eliminate, the normal function of this protein. If cadherin 23 does not work properly, deafness results from disrupted development of stereocilia in the inner ear.

Researchers speculate that some children with nonsyndromic hearing loss caused by a CDH23 mutation may actually have an early form of Usher syndrome. A few children with CDH23-related deafness have gone on to develop retinitis pigmentosa, a vision disorder characteristic of Usher syndrome, later in life.

Usher syndrome - caused by mutations in the CDH23 gene

More than 30 mutations in the CDH23 gene have been shown to cause Usher syndrome type 1D. Many of these mutations change one DNA building block (base pair) in the CDH23 gene. Most genetic changes disrupt protein production, resulting in an abnormally small, nonfunctional version of cadherin 23. Insertions of small amounts of DNA in the CDH23 gene can also result in a nonfunctional version of this protein. A deficiency of cadherin 23 can lead to improper development of the inner ear and retina, resulting in the loss of hearing and vision typical of Usher syndrome.

Where is the CDH23 gene located?

Cytogenetic Location: 10q22.1

Molecular Location on chromosome 10: base pairs 71,396,934 to 71,815,947

The CDH23 gene is located on the long (q) arm of chromosome 10 at position 22.1.

The CDH23 gene is located on the long (q) arm of chromosome 10 at position 22.1.

More precisely, the CDH23 gene is located from base pair 71,396,934 to base pair 71,815,947 on chromosome 10.

See How do geneticists indicate the location of a gene? ( in the Handbook.

Where can I find additional information about CDH23?

You and your healthcare professional may find the following resources about CDH23 helpful.

You may also be interested in these resources, which are designed for genetics professionals and researchers.

What other names do people use for the CDH23 gene or gene products?

  • cadherin-23
  • cadherin-like 23
  • cadherin related 23
  • CDHR23
  • DFNB12
  • KIAA1774
  • KIAA1812
  • otocadherin
  • USH1D

See How are genetic conditions and genes named? ( in the Handbook.

What glossary definitions help with understanding CDH23?

amino acid ; autosomal ; autosomal recessive ; base pair ; cell ; cell membrane ; deficiency ; DNA ; gene ; mutation ; photoreceptor ; protein ; recessive ; retina ; syndrome

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.


  • Ahmed ZM, Riazuddin S, Riazuddin S, Wilcox ER. The molecular genetics of Usher syndrome. Clin Genet. 2003 Jun;63(6):431-44. Review. (
  • Astuto LM, Bork JM, Weston MD, Askew JW, Fields RR, Orten DJ, Ohliger SJ, Riazuddin S, Morell RJ, Khan S, Riazuddin S, Kremer H, van Hauwe P, Moller CG, Cremers CW, Ayuso C, Heckenlively JR, Rohrschneider K, Spandau U, Greenberg J, Ramesar R, Reardon W, Bitoun P, Millan J, Legge R, Friedman TB, Kimberling WJ. CDH23 mutation and phenotype heterogeneity: a profile of 107 diverse families with Usher syndrome and nonsyndromic deafness. Am J Hum Genet. 2002 Aug;71(2):262-75. Epub 2002 Jun 19. (
  • Boëda B, El-Amraoui A, Bahloul A, Goodyear R, Daviet L, Blanchard S, Perfettini I, Fath KR, Shorte S, Reiners J, Houdusse A, Legrain P, Wolfrum U, Richardson G, Petit C. Myosin VIIa, harmonin and cadherin 23, three Usher I gene products that cooperate to shape the sensory hair cell bundle. EMBO J. 2002 Dec 16;21(24):6689-99. (
  • Bolz H, von Brederlow B, Ramírez A, Bryda EC, Kutsche K, Nothwang HG, Seeliger M, del C-Salcedó Cabrera M, Vila MC, Molina OP, Gal A, Kubisch C. Mutation of CDH23, encoding a new member of the cadherin gene family, causes Usher syndrome type 1D. Nat Genet. 2001 Jan;27(1):108-12. (
  • Bork JM, Peters LM, Riazuddin S, Bernstein SL, Ahmed ZM, Ness SL, Polomeno R, Ramesh A, Schloss M, Srisailpathy CR, Wayne S, Bellman S, Desmukh D, Ahmed Z, Khan SN, Kaloustian VM, Li XC, Lalwani A, Riazuddin S, Bitner-Glindzicz M, Nance WE, Liu XZ, Wistow G, Smith RJ, Griffith AJ, Wilcox ER, Friedman TB, Morell RJ. Usher syndrome 1D and nonsyndromic autosomal recessive deafness DFNB12 are caused by allelic mutations of the novel cadherin-like gene CDH23. Am J Hum Genet. 2001 Jan;68(1):26-37. Epub 2000 Nov 21. (
  • El-Amraoui A, Petit C. Usher I syndrome: unravelling the mechanisms that underlie the cohesion of the growing hair bundle in inner ear sensory cells. J Cell Sci. 2005 Oct 15;118(Pt 20):4593-603. Review. (
  • Keats BJ, Savas S. Genetic heterogeneity in Usher syndrome. Am J Med Genet A. 2004 Sep 15;130A(1):13-6. Review. (
  • Lagziel A, Ahmed ZM, Schultz JM, Morell RJ, Belyantseva IA, Friedman TB. Spatiotemporal pattern and isoforms of cadherin 23 in wild type and waltzer mice during inner ear hair cell development. Dev Biol. 2005 Apr 15;280(2):295-306. (
  • NCBI Gene (
  • Pennings RJ, Topsakal V, Astuto L, de Brouwer AP, Wagenaar M, Huygen PL, Kimberling WJ, Deutman AF, Kremer H, Cremers CW. Variable clinical features in patients with CDH23 mutations (USH1D-DFNB12). Otol Neurotol. 2004 Sep;25(5):699-706. (
  • Reiners J, Nagel-Wolfrum K, Jürgens K, Märker T, Wolfrum U. Molecular basis of human Usher syndrome: deciphering the meshes of the Usher protein network provides insights into the pathomechanisms of the Usher disease. Exp Eye Res. 2006 Jul;83(1):97-119. Epub 2006 Mar 20. Review. (
  • Siemens J, Kazmierczak P, Reynolds A, Sticker M, Littlewood-Evans A, Müller U. The Usher syndrome proteins cadherin 23 and harmonin form a complex by means of PDZ-domain interactions. Proc Natl Acad Sci U S A. 2002 Nov 12;99(23):14946-51. Epub 2002 Oct 29. (
  • Siemens J, Lillo C, Dumont RA, Reynolds A, Williams DS, Gillespie PG, Müller U. Cadherin 23 is a component of the tip link in hair-cell stereocilia. Nature. 2004 Apr 29;428(6986):950-5. Epub 2004 Mar 31. (
  • Zheng QY, Yan D, Ouyang XM, Du LL, Yu H, Chang B, Johnson KR, Liu XZ. Digenic inheritance of deafness caused by mutations in genes encoding cadherin 23 and protocadherin 15 in mice and humans. Hum Mol Genet. 2005 Jan 1;14(1):103-11. Epub 2004 Nov 10. (


The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? ( in the Handbook.

Reviewed: February 2007
Published: November 23, 2015