Keratin 16 (KRT16 in human, Krt16 in mouse), a type I intermediate filament protein, is constitutively expressed in epithelial appendages and is induced in the epidermis upon wounding and other stressors. Mutations altering the coding sequence of KRT16 cause pachyonychia congenita (PC), a rare autosomal dominant disorder characterized by hypertrophic nail dystrophy, oral leukokeratosis, and pal...

Pachyonychia congenita is a rare genodermatosis that can affect the larynx. Laryngeal obstruction is very unusual with only a few cases reported. A 2-year-old girl presented with typical clinical features of pachyonychia congenita shortly after birth. At age 9 months, following an upper respiratory infection, she developed stridor and hoarseness and was found to have severe laryngeal obstructio...

Pachyonychia congenita is a rare type of ectodermal dysplasia further classified into 4 types. Cutaneous manifestations seen in most of the cases of Pachyonychia congenita include palmoplantar keratoderma, follicular hyperkeratosis, wedge shaped nails, oral leukokeratosis and woolly hair. A 25-year-old male presented to us with thickened nails and scanty scalp hair. On examination, we noticed h...

Your ‘Out of the Box’ columnist (Cannon, 2005) says he is unconfined, and hence able to commend the aphorism of the Tao Te Ching: ‘Be really whole, and all things will come to you’. I have no idea what this aphorism means. If it means anything, I doubt if it can be proved to be true or untrue, so I am not very interested in it. Is it wise for nutritionists to dispense with boxes entirely if, li...

We report a novel KRT13 germ line variant that causes white sponge nevus (WSN) with mucosal dysplasia. Genital, vaginal, and cervical WSN were observed in four female patients, of whom two had premalignant cervical lesions at young age. Two of the 12 patients with oral WSN developed oral squamous cell carcinoma.

White sponge nevus (WSN) is an autosomal dominant skin disorder characterized by white, corrugated and diffuse plaques mainly affecting the oral mucosa. The condition has a high penetrance and variable expressivity, but familial reports are uncommon. This report presents a familial case of WSN in which two sisters are affected by the disorder.

White sponge nevus (WSN) is a rare autosomal dominant disorder with variable penetrance (1). It was first described by Hyde in 1909 (2); in 1935 Cannon named it white sponge nevus (3). Several other names have been applied to this condition: HydeCannon’s disease, familial white folded dysplasia, congenital leukokeratosis mucose oris, hereditary leukokeratosis, and white folded gingivostomatosis...

Pachyonychia congenita (PC) is a rare genodermatosis affecting the nails, skin, oral mucosae, larynx, hair, and teeth. Pathogenic mutations in keratins K6a or K16 are associated with the PC-1 phenotype whereas K6b and K17 mutations are associated with the PC-2 phenotype. Analysis of clinical, pathological, and genetic data from the literature and two research registries reveal that >97% of PC c...

A case is presented of white plaques occurring predominantly on the vulvar mucosa of a 28-year-old female diagnosed as white sponge nevus (WSN). WSN is a rare, autosomal dominant disorder involving mucous membranes. It predominantly affects the oral mucosa; however, it has been reported to rarely involve extraoral mucosal sites. In this case, histology and family history were key features leadi...

White sponge nevus (WSN) is an autosomal dominant hereditary disease. Keratin 4 (KRT4) and Keratin 13 (KRT13) gene mutations were involved in the WSN. We recruited two WSN Chinese families, and oral lesion biopsy with hematoxylin and eosin staining showed that patients had significant pathological characteristics. The mutations of KRT4 and KRT13 gene were detected by PCR and direct sequencing. ...