INTRODUCTION: The inherited palmoplantar keratodermas (PPKs) are a heterogeneous group of genodermatoses, characterised by thickening of the epidermis of the palms and soles. No classification system unites satisfactorily clinical presentation, pathology and molecular pathogenesis. There are four patterns of hyperkeratosis: striate, focal, diffuse, and punctate. Mutations in desmoglein-1 (DSG1), a transmembrane glycoprotein, have been reported primarily in striate, but also in focal and diffuse PPKs.
OBJECTIVES: We report seven unrelated pedigrees with dominantly inherited PPK due to mutations in the DSG1 gene, with marked phenotypic variation.
METHODS: Genomic DNA from each family was isolated, and individual exons amplified by polymerase chain reaction (PCR). Sanger sequencing was employed to identify mutations.
RESULTS: Mutation analysis identified novel mutations in five families (p.Tyr126Hisfs*2, p.Ser521Tyrfs*2, p.Trp3*, p.Asp591Phefs*9 and p.Met249Ilefs*6) with striate palmar involvement and varying focal or diffuse plantar disease, and the recurrent mutation c.76C>T, p.Arg26*, in two families with variable PPK patterns.
CONCLUSION: We report one recurrent and five novel DSG1 mutations, causing varying patterns of PPK, highlighting the clinical heterogeneity arising from mutations in this gene. This article is protected by copyright. All rights reserved.