A novel missense mutation of keratin 17 gene in a chinese family with steatocystoma multiplex

Steatocystoma multiplex suppurativa: case report of a rare condition

Steatocystoma multiplex is a rare genetic disorder characterized by the presence of hamartomatous malformations at the junction of the pilosebaceous duct. It consists of encapsulated cystic lesions in the dermis, with adjacent sebaceous gland. When associated with inflammation, resembling hidradenitis, it is called steatocystoma multiplex suppurativa, a condition rarely reported. This is the first case of steatocystoma multiplex suppurativa reported in the Brazilian literature. Female patient, 23 years old, with papular and nodular cystic lesions that started in the armpits and groin, later spreading to the trunk, lower limbs, anticubital fossa, face and scalp. The presence of papular-nodular lesions associated with disseminated hidradenitis-like lesions in flexural areas and the histopathological diagnosis of steatocystoma defined the diagnosis of steatocystoma multiplex suppurativa.

Steatocystoma multiplex is associated with the R94C mutation in the KRTl7 gene

Steatocystoma multiplex (SM) is an uncommon disorder, characterized by numerous skin-colored subcutaneous cysts. A number of SM pedigrees have been identified with mutations in the keratin 17 (KRT17) gene. The present study examined a four-generation Chinese pedigree with an autosomal dominant mode of inheritance and examined its genetic basis. A review of the literature on KRT17 gene mutations in the SM pedigree was also performed to investigate the KRT17 gene mutation and genotype-phenotype correlation. Exon 1 of the KRTl7 gene was amplified using polymerase chain reaction (PCR) from genomic DNA obtained, which was obtained from 25 family members in the selected Chinese pedigree and from 100 unrelated control individuals. The DNA was then subjected to automatic DNA sequencing. Genealogical investigations demonstrated an autosomal dominant pattern, and direct sequencing of the PCR product revealed a heterozygous mutation, c.280C/T (R94C), which was located in exon 1 of the KRT17 gene in all 10 affected family members. The mutation was not identified in the 15 unaffected family members or in the 100 unrelated control individuals. Therefore, the present study identified a causative mutation in the KRT17 gene in a large Chinese SM pedigree, exhibiting autosomal dominance. A review of the literature suggested that, in addition to the mutation factor, other modifying factors contribute to the phenotype of familial SM.

Steatocystoma multiplex with hair shaft abnormalities

Steatocystoma multiplex (SM) is an unusual benign disorder of the pilosebaceous duct characterized by multiple cysts with little or no nail and hair involvement. We report a 30-year-old woman with multiple cystic nodules located on the neck, axillae and forearms as well as patchy scalp alopecia. Histopathological examination of the lesions was diagnostic of SM. Trichoscopy revealed pili torti and pili canaliculi. This patient represents an unusual clinical presentation of SM because of the presence of hair abnormalities.