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COCH

Reviewed November 2006

What is the official name of the COCH gene?

The official name of this gene is “cochlin.”

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

What is the normal function of the COCH gene?

The COCH gene provides instructions for making a protein called cochlin. This protein is abundant in certain parts of the inner ear called the cochlea and the vestibular system. The cochlea is a snail-shaped structure that helps process sound, and the vestibular system consists of fluid-filled canals that help maintain the body's balance and orientation in space. Cochlin is exported from cells in the cochlea and vestibular system and becomes part of the extracellular matrix. The extracellular matrix is an intricate lattice that forms in the space between cells and provides structural support. Two regions of the cochlin protein, called the LCCL and vWFA domains, probably coordinate cochlin's interactions with other molecules in the extracellular matrix. These interactions are important in forming the extracellular matrix and keeping it organized. Although the exact role of cochlin remains unknown, it likely plays a role in the structure of the inner ear.

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

nonsyndromic deafness - caused by mutations in the COCH gene

Several COCH gene mutations have been identified in individuals with a form of nonsyndromic deafness (hearing loss without related signs and symptoms affecting other parts of the body) called DFNA9. These mutations either change or delete a protein building block (amino acid) used to make cochlin. Most of the reported COCH gene mutations affect the LCCL domain and probably impair cochlin's interactions with other molecules in the extracellular matrix. One mutation occurs outside the LCCL domain and likely affects cochlin's 3-dimensional shape.

It is not fully understood how COCH gene mutations lead to hearing loss and in some cases, problems with balance and orientation. The altered cochlin protein may fail to become part of the extracellular matrix due to impaired interactions with other molecules, or it may disrupt the organization of the extracellular matrix. Disturbing the extracellular matrix may cause structural changes in the inner ear that affect hearing and balance. Cochlin also appears to be part of abnormal deposits that form in the inner ear of people with DFNA9 deafness. These deposits may damage nerves that are critical for the hearing process.

Where is the COCH gene located?

Cytogenetic Location: 14q11.2-q13

Molecular Location on chromosome 14: base pairs 30,874,534 to 30,895,078

The COCH gene is located on the long (q) arm of chromosome 14 between positions 11.2 and 13.

The COCH gene is located on the long (q) arm of chromosome 14 between positions 11.2 and 13.

More precisely, the COCH gene is located from base pair 30,874,534 to base pair 30,895,078 on chromosome 14.

See How do geneticists indicate the location of a gene? (http://ghr.nlm.nih.gov/handbook/howgeneswork/genelocation) in the Handbook.

Where can I find additional information about COCH?

You and your healthcare professional may find the following resources about COCH 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 COCH gene or gene products?

  • coagulation factor C homolog, cochlin (Limulus polyphemus)
  • COCH5B2
  • COCH_HUMAN
  • deafness, autosomal dominant 9
  • DFNA9

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What glossary definitions help with understanding COCH?

amino acid ; autosomal ; autosomal dominant ; coagulation ; cochlea ; domain ; extracellular ; extracellular matrix ; gene ; mutation ; protein ; vestibular system

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References

  • Finsterer J, Fellinger J. Nuclear and mitochondrial genes mutated in nonsyndromic impaired hearing. Int J Pediatr Otorhinolaryngol. 2005 May;69(5):621-47. Review. (http://www.ncbi.nlm.nih.gov/pubmed/15850684?dopt=Abstract)
  • Friedman TB, Griffith AJ. Human nonsyndromic sensorineural deafness. Annu Rev Genomics Hum Genet. 2003;4:341-402. Review. (http://www.ncbi.nlm.nih.gov/pubmed/14527306?dopt=Abstract)
  • Grabski R, Szul T, Sasaki T, Timpl R, Mayne R, Hicks B, Sztul E. Mutations in COCH that result in non-syndromic autosomal dominant deafness (DFNA9) affect matrix deposition of cochlin. Hum Genet. 2003 Oct;113(5):406-16. Epub 2003 Aug 20. (http://www.ncbi.nlm.nih.gov/pubmed/12928864?dopt=Abstract)
  • Ikezono T, Shindo S, Li L, Omori A, Ichinose S, Watanabe A, Kobayashi T, Pawankar R, Yagi T. Identification of a novel Cochlin isoform in the perilymph: insights to Cochlin function and the pathogenesis of DFNA9. Biochem Biophys Res Commun. 2004 Feb 6;314(2):440-6. (http://www.ncbi.nlm.nih.gov/pubmed/14733925?dopt=Abstract)
  • Nagy I, Horváth M, Trexler M, Répássy G, Patthy L. A novel COCH mutation, V104del, impairs folding of the LCCL domain of cochlin and causes progressive hearing loss. J Med Genet. 2004 Jan;41(1):e9. (http://www.ncbi.nlm.nih.gov/pubmed/14729849?dopt=Abstract)
  • NCBI Gene (http://www.ncbi.nlm.nih.gov/gene/1690)
  • Robertson NG, Cremers CW, Huygen PL, Ikezono T, Krastins B, Kremer H, Kuo SF, Liberman MC, Merchant SN, Miller CE, Nadol JB Jr, Sarracino DA, Verhagen WI, Morton CC. Cochlin immunostaining of inner ear pathologic deposits and proteomic analysis in DFNA9 deafness and vestibular dysfunction. Hum Mol Genet. 2006 Apr 1;15(7):1071-85. Epub 2006 Feb 15. (http://www.ncbi.nlm.nih.gov/pubmed/16481359?dopt=Abstract)
  • Robertson NG, Hamaker SA, Patriub V, Aster JC, Morton CC. Subcellular localisation, secretion, and post-translational processing of normal cochlin, and of mutants causing the sensorineural deafness and vestibular disorder, DFNA9. J Med Genet. 2003 Jul;40(7):479-86. (http://www.ncbi.nlm.nih.gov/pubmed/12843317?dopt=Abstract)
  • Street VA, Kallman JC, Robertson NG, Kuo SF, Morton CC, Phillips JO. A novel DFNA9 mutation in the vWFA2 domain of COCH alters a conserved cysteine residue and intrachain disulfide bond formation resulting in progressive hearing loss and site-specific vestibular and central oculomotor dysfunction. Am J Med Genet A. 2005 Dec 1;139A(2):86-95. (http://www.ncbi.nlm.nih.gov/pubmed/16261627?dopt=Abstract)

 

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? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: November 2006
Published: August 18, 2014