KRT6A Gene

The KRT6A gene (KRT6A is the acronym for keratin 6A) is a protein coding gene located on chromosome 12q13.13. Diseases associated with KRT6A include:

Pachyonychia congenita 3 with mutation in KRT6a/KRT16 (Jadassohn-Lewandowski ).

An important paralogue of this gene is KRT6B.

KRT6a belongs to the family of keratin genes. The protein of the same name encoded by this gene, keratin 6a, a type II cytokeratin, consists of basic or neutral proteins arranged in pairs of heterotypic keratin chains. Type II cytokeratins are clustered in a region of chromosome 12q12-q13. To date, six type II cytokeratins (KRT6) have been identified. They are expressed during differentiation of simple and stratified epithelial tissues. Peptides from the C-terminal region of the protein have antimicrobial activity against bacterial pathogens.

The multiplicity of these keratin genes is attributed to successive gene duplications. The genes, along with family members KRT16 and/or KRT17, are expressed in the filiform papillae of the tongue, the stratified epithelial lining of the oral mucosa and esophagus, the outer root sheath of hair follicles, and glandular epithelia. KRT6a is also expressed in bladder carcinoma (Guo CC et al. 2020; Ochoa AE et al. 2016). It serves to differentiate between the basal and luminal subtypes of muscle-invasive bladder carcinoma.

1. Bai ZL et al. (2009) Two mutations of the KRT6A gene in Chinese patients with pachyonychia congenita type I. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 26:514-517.
2. Guo CC et al (2020) Assessment of Luminal and Basal Phenotypes in Bladder Cancer Sci Rep 10: 9743.
3. Li Y et al. (2021) A KRT6A mutation p.Ile462Asn in a Chinese family with pachyonychia congenita, and identification of maternal mosaicism: a case report. BMC Med Genomics 14: 259.
4. Ochoa AE et al. (2016) Specific micro-RNA expression patterns distinguish the basal and luminal subtypes of muscle-invasive bladder cancer. Oncotarget 7: 80164-80174.
5. Tous-Romero F et al (2019) Thick nails, plantar keratoderma, follicular hyperkeratosis, and leukokeratosis associated with a novel mutation in KRT6A gene. Int J Dermatol 58:E89-E90.