RESUMO
Epidermolytic palmoplantar keratoderma (EPPK), an autosomal-dominant genodermatosis, is the most frequently occurring hereditary palmoplantar keratoderma. EPPK is characterized by hyperkeratosis of the palms and soles. Approximately 90% of patients present with mutations in the KRT9 gene, which encodes for keratin 9. Many of these mutations are located within the highly conserved coil 1A region of the alpha-helical rod domain of keratin 9, an important domain for keratin heterodimerization. The objective was to assess the clinical and molecular characteristics of a Mexican family with EPPK. The clinical characteristics of members of this family were analyzed. The KRT9 gene of affected members was polymerase chain reaction amplified from genomic DNA and sequenced. All affected members of the family had hyperkeratosis of the palms and soles with knuckle pads. The R163W mutation in the KRT9 gene was present in all affected individuals who were tested. Although R163W is the most frequent KRT9 mutation in patients with EPPK, only two families have been reported with knuckle pads associated with this mutation. Our findings indicate that knuckle pads can be associated with EPPK and the R163W mutation in a family with a genetic background different from that described here.
Assuntos
Epiderme/patologia , Queratina-9/genética , Ceratodermia Palmar e Plantar Epidermolítica/genética , Ceratodermia Palmar e Plantar Epidermolítica/patologia , Adolescente , Adulto , Criança , Saúde da Família , Feminino , Humanos , Lactente , Masculino , México , Pessoa de Meia-Idade , LinhagemRESUMO
A 22-year-old woman had an unusual congenital skin disorder in the form of ichthyosis characterized by innumerable keratotic plugs, resulting in a peculiar sievelike appearance. On histopathologic examination the epidermis showed a pronounced orthohyperkeratosis. The keratotic plugs seemed to emerge from the infundibular region of hair follicles. Immunohistochemical characterization revealed a normal keratin and filaggrin expression. Oral treatment with isotretinoin resulted in a reduction of the hyperkeratosis. Because we could not find any previously reported similar case, we propose the new name "ichthyosis cribriformis," which means "sievelike ichthyosis."