Keratin 17 Mutations Cause Either Steatocystoma Multiplex or Pachyonychia Congenita Type 2

The study identified that mutations in the keratin 17 (K17) gene were responsible for both pachyonychia congenita type 2 (PC-2) and steatocystoma multiplex, with the phenotypic outcome being independent of the specific mutation. Three unrelated families with K17 mutations were examined, revealing that two families shared the same missense mutation (R94C) but exhibited different phenotypes: one with classical PC-2 features and the other with steatocystoma multiplex. A third family with PC-2 had a different mutation (N92S). The research highlighted that K17 mutations were a common underlying cause for both conditions, expanding the known distinct mutations in K17 to 11.