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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 2014

What is the official name of the KRT13 gene?

The official name of this gene is “keratin 13, type I.”

KRT13 is the gene's official symbol. The KRT13 gene is also known by other names, listed below.

What is the normal function of the KRT13 gene?

The KRT13 gene provides instructions for making a protein called keratin 13. Keratins are a group of tough, fibrous proteins that form the structural framework of epithelial cells, which are cells that line the surfaces and cavities of the body. Keratin 13 is found in the moist lining (mucosae) of the mouth, nose, esophagus, genitals, and anus.

Keratin 13 partners with a similar protein, keratin 4 (produced from the KRT4 gene), to form molecules known as intermediate filaments. These filaments assemble into strong networks that provide strength and resilience to the different mucosae. Networks of intermediate filaments protect the mucosae from being damaged by friction or other everyday physical stresses.

Does the KRT13 gene share characteristics with other genes?

The KRT13 gene belongs to a family of genes called KRT (keratins).

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 KRT13 gene related to health conditions?

white sponge nevus - caused by mutations in the KRT13 gene

At least five KRT13 gene mutations have been found to cause white sponge nevus, a condition that results in the formation of white patches of tissue called nevi (singular: nevus) that appear as thickened, velvety, sponge-like tissue. These nevi most often occur on the mouth (oral) mucosa (plural: mucosae). Rarely, white sponge nevus occurs on the mucosae of the nose, esophagus, genitals, or anus.

The KRT13 gene mutations that cause white sponge nevus disrupt the structure of keratin 13. As a result, keratin 13 does not fit together properly with keratin 4, leading to the formation of irregular intermediate filaments that are easily damaged with little friction or trauma. Fragile intermediate filaments in the oral mucosa might be damaged when eating or brushing one's teeth. Damage to intermediate filaments leads to inflammation and promotes the abnormal growth and division (proliferation) of epithelial cells, causing the mucosae to thicken and resulting in white sponge nevus.

Where is the KRT13 gene located?

Cytogenetic Location: 17q21.2

Molecular Location on chromosome 17: base pairs 41,500,981 to 41,505,613

(Homo sapiens Annotation Release 107, GRCh38.p2) (NCBI (

The KRT13 gene is located on the long (q) arm of chromosome 17 at position 21.2.

The KRT13 gene is located on the long (q) arm of chromosome 17 at position 21.2.

More precisely, the KRT13 gene is located from base pair 41,500,981 to base pair 41,505,613 on chromosome 17.

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

Where can I find additional information about KRT13?

You and your healthcare professional may find the following resources about KRT13 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 KRT13 gene or gene products?

  • CK13
  • CK-13
  • cytokeratin 13
  • cytokeratin-13
  • K1C13_HUMAN
  • K13
  • keratin-13
  • keratin 13
  • keratin, type I cytoskeletal 13

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

What glossary definitions help with understanding KRT13?

anus ; cytokeratin ; epithelial ; esophagus ; gene ; genitals ; inflammation ; intermediate filaments ; keratin ; mucosa ; mucous ; mucous membrane ; proliferation ; protein ; resilience ; tissue ; trauma

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


  • NCBI Gene (
  • Nishizawa A, Nakajima R, Nakano H, Sawamura D, Takayama K, Satoh T, Yokozeki H. A de novo missense mutation in the keratin 13 gene in oral white sponge naevus. Br J Dermatol. 2008 Sep;159(4):974-5. doi: 10.1111/j.1365-2133.2008.08716.x. Epub 2008 Jul 4. (
  • Rugg E, Magee G, Wilson N, Brandrup F, Hamburger J, Lane E. Identification of two novel mutations in keratin 13 as the cause of white sponge naevus. Oral Dis. 1999 Oct;5(4):321-4. (
  • Shibuya Y, Zhang J, Yokoo S, Umeda M, Komori T. Constitutional mutation of keratin 13 gene in familial white sponge nevus. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Nov;96(5):561-5. (


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 2014
Published: February 1, 2016