pachyonychia

Pachyonychia congenita is an autosomal dominant skin disorder.

Pachyonychia congenita is caused by disruptions or changes (mutations) of one of several different genes.

A Unilateral palmoplantar verrucous nevus is a cutaneous condition that has features of pachyonychia congenita.

Some authors propose that steatocystoma multiplex is simply a variant of pachyonychia congenita type 2 because they both share the same underlying etiology.

Mutations in the gene encoding this protein lead to Jackson-Lawler type pachyonychia congenita and steatocystoma multiplex.

Pachyonychia congenita type I (Jadassohn-Lewandowsky syndrome)

Jadassohn-Lewandowsky syndrome: An ectodermal dysplasia characterized by onychogryposis, hyperkeratosis, leukoplakia, hyperhidrosis and pachyonychia congenita.

Keratin 6B has been associated with the PC2 variant of pachyonychia congenita where affected individuals may develop more skin cysts than the PC1 type.

Mutations in the gene encoding this protein are associated with the genetic skin disorders pachyonychia congenita, non-epidermolytic palmoplantar keratoderma and unilateral palmoplantar verrucous nevus.

Pachyonychia congenita type 2, an autosomal dominant inherited disorder, is characterized by hypertrophic nail dystrophy, focal keratoderma, multiple pilosebaceous cysts, and a variety of conditions associated with ectodermal dysplasia.

Pachyonychia congenita type II (Jackson-Lawler pachyonychia congenita, Jackson-Sertoli syndrome)

In previous reports, specific mutations were attributed to early-onset cyst formation in pachyonychia congenita type 2 and steatocystoma multiplex; however, more recent reports suggest that the age of onset is multifactorial.

In the familial form of steatocystoma multiplex, mutations are localized to the keratin 17 (K17) gene in areas identical to mutations found in patients with pachyonychia congenita type 2 (PC-2).

To date, 14 mutations have been described in patients with either steatocystoma multiplex or pachyonychia congenita type 2, all of which are localized to the helix initiation domain (1A domain) of the K17 gene.

Pachyonychia congenita follows an autosomal dominant pattern of inheritance, which means the defective gene is located on an autosome, and only one copy of the gene is required to inherit the disorder from a parent who has the disorder.

Pachyonychia congenita type I (also known as "Jadassohn-Lewandowsky syndrome") is an autosomal dominant keratoderma that principally involves the plantar surfaces, but also with nails changes that may be evident at birth but more commonly develop within the first few months of life.

Pachyonychia Congenita Type 1 (PC-1) Pachyonychia Congenita Type 2 (PC-2) Pachyonychia congenita is a rare disorder inherited in an autosomal dominant fashion.

Keratin 17 is expressed in several epithelial structures, most notably in sebaceous glands, the outer root sheath of hair follicles, and the nail bed; its expression correlates well to the clinical phenotypic expression of both steatocystoma multiplex and pachyonychia congenita type 2.

Mutations in the gene encoding this protein have been associated with pachyonychia congenita, an inherited disorder of the epithelial tissues in which this keratin is expressed, particularly leading to structural abnormalities of the nails, the epidermis of the palms and soles, and oral epithelia.