KRT4 Gene

The KRT4 gene (KRT4 stands for keratin 4) is a protein coding gene located on chromosome 12q13.13. An important paralog of this gene is KRT13. The protein encoded by this gene belongs to the cytokeratins family. Keratin4, like keratin 13, is a mucosal-specific keratin.

Type II cytokeratins consist of basic or neutral proteins arranged in pairs of heterotypic keratin chains that are co-expressed during differentiation of simple and stratified epithelial tissues. Type II cytokeratins are clustered in a region of chromosome 12q12-q13.

Mutations in the keratin4 gene are associated with White Sponge Nevus(nevus spongiosus albus mucosae), which is characterized by oral, esophageal, and anal leukoplakia (Westin M et al 2018).

1. Aloi FG et al (1988) White sponge nevus with epidermolytic changes. Dermatologica 177: 323-326
2. Cannon AB (1935) White sponge nevus of the mucosa (nevus spongiosus albus mucosae). Arch Dermatol Syph 31: 365
3. Chao SC et al (2003) A novel mutation in the keratin 4 gene causing white sponge nevus. Br J Dermatol 148: 1125-1128.
4. Mostaccioli S et al (1997) White sponge nevus is caused by mutations in mucosal keratins. Eur J Dermatol 7: 405-408.
5. Westin M et al (2018) Mutations in the genes for keratin-4 and keratin-13 in Swedish patients with white sponge nevus. J Oral Pathol Med 47:152-157.