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

White sponge nevus

Reviewed February 2014

What is white sponge nevus?

White sponge nevus is a condition characterized by the formation of white patches of tissue called nevi (singular: nevus) that appear as thickened, velvety, sponge-like tissue. The nevi are most commonly found on the moist lining of the mouth (oral mucosa), especially on the inside of the cheeks (buccal mucosa). Affected individuals usually develop multiple nevi. Rarely, white sponge nevi also occur on the mucosae (singular: mucosa) of the nose, esophagus, genitals, or anus. The nevi are caused by a noncancerous (benign) overgrowth of cells.

White sponge nevus can be present from birth but usually first appears during early childhood. The size and location of the nevi can change over time. In the oral mucosa, both sides of the mouth are usually affected. The nevi are generally painless, but the folds of extra tissue can promote bacterial growth, which can lead to infection that may cause discomfort. The altered texture and appearance of the affected tissue, especially the oral mucosa, can be bothersome for some affected individuals.

How common is white sponge nevus?

The exact prevalence of white sponge nevus is unknown, but it is estimated to affect less than 1 in 200,000 individuals worldwide.

What genes are related to white sponge nevus?

Mutations in the KRT4 or KRT13 gene cause white sponge nevus. These genes provide instructions for making proteins called keratins. 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 and make up the different mucosae. The keratin 4 protein (produced from the KRT4 gene) and the keratin 13 protein (produced from the KRT13 gene) partner together to form molecules known as intermediate filaments. These filaments assemble into 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.

Mutations in the KRT4 or KRT13 gene disrupt the structure of the keratin protein. As a result, keratin 4 and keratin 13 are mismatched and do not fit together properly, 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.

Related Gene(s)

Changes in these genes are associated with white sponge nevus.

  • KRT13
  • KRT4

How do people inherit white sponge nevus?

This condition is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell can be sufficient to cause the disorder. However, some people who have a mutation that causes white sponge nevus do not develop these abnormal growths; this phenomenon is called reduced penetrance.

Where can I find information about diagnosis or management of white sponge nevus?

These resources address the diagnosis or management of white sponge nevus and may include treatment providers.

  • Genetic Testing Registry: White sponge nevus of cannon (

You might also find information on the diagnosis or management of white sponge nevus in Educational resources and Patient support.

General information about the diagnosis ( and management ( of genetic conditions is available in the Handbook. Read more about genetic testing (, particularly the difference between clinical tests and research tests (

To locate a healthcare provider, see How can I find a genetics professional in my area? ( in the Handbook.

Where can I find additional information about white sponge nevus?

You may find the following resources about white sponge nevus helpful. These materials are written for the general public.

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

What other names do people use for white sponge nevus?

  • Cannon's disease
  • familial white folded mucosal dysplasia
  • hereditary leukokeratosis
  • hereditary mucosal leukokeratosis
  • hereditary oral keratosis
  • leukokeratosis, hereditary mucosal
  • leukokeratosis of oral mucosa
  • nevus of Cannon
  • white folded gingivostomatosis
  • white gingivostomatitis
  • white sponge naevus
  • white sponge nevus of Cannon
  • white sponge nevus of mucosa
  • WSN

For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines ( and How are genetic conditions and genes named? ( in the Handbook.

What if I still have specific questions about white sponge nevus?

Ask the Genetic and Rare Diseases Information Center (

What glossary definitions help with understanding white sponge nevus?

anus ; autosomal ; autosomal dominant ; benign ; cell ; dysplasia ; epithelial ; esophagus ; familial ; gene ; genitals ; hereditary ; infection ; inflammation ; inherited ; intermediate filaments ; keratin ; keratosis ; leukokeratosis ; mucosa ; mucous ; mucous membrane ; mutation ; penetrance ; prevalence ; proliferation ; protein ; resilience ; tissue ; trauma

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


  • Aghbali A, Pouralibaba F, Eslami H, Pakdel F, Jamali Z. White sponge nevus: a case report. J Dent Res Dent Clin Dent Prospects. 2009 Spring;3(2):70-2. doi: 10.5681/joddd.2009.017. Epub 2009 Jun 5. (
  • Kimura M, Nagao T, Machida J, Warnakulasuriya S. Mutation of keratin 4 gene causing white sponge nevus in a Japanese family. Int J Oral Maxillofac Surg. 2013 May;42(5):615-8. doi: 10.1016/j.ijom.2012.10.030. Epub 2012 Nov 24. (
  • Marrelli M, Tatullo M, Dipalma G, Inchingolo F. Oral infection by Staphylococcus aureus in patients affected by White Sponge Nevus: a description of two cases occurred in the same family. Int J Med Sci. 2012;9(1):47-50. Epub 2011 Nov 18. (
  • Martelli H Jr, Pereira SM, Rocha TM, Nogueira dos Santos PL, Batista de Paula AM, Bonan PR. White sponge nevus: report of a three-generation family. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007 Jan;103(1):43-7. Epub 2006 Sep 1. (
  • 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. (
  • Songu M, Adibelli H, Diniz G. White sponge nevus: clinical suspicion and diagnosis. Pediatr Dermatol. 2012 Jul-Aug;29(4):495-7. doi: 10.1111/j.1525-1470.2011.01414.x. Epub 2012 Feb 22. Review. (
  • Zhang JM, Yang ZW, Chen RY, Gao P, Zhang YR, Zhang LF. Two new mutations in the keratin 4 gene causing oral white sponge nevus in Chinese family. Oral Dis. 2009 Jan;15(1):100-5. doi: 10.1111/j.1601-0825.2008.01498.x. Epub 2008 Oct 25. (


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