Annular epidermolytic ichthyosis with palmoplantar keratosis: a unique phenotype associated with interfamilial phenotypic heterogeneity

Eur J Dermatol. 2020 Jun 1;30(3):294-299. doi: 10.1684/ejd.2020.3764.


Background: Annular epidermolytic ichthyosis (AEI) is a rare autosomal dominant ichthyosis that was recently described in 10 separate families in the English literature. There are no reports on the phenotypic heterogeneity of AEI.

Objectives: We investigated, for the first time, a large Chinese AEI pedigree exhibiting interfamilial phenotypic heterogeneity.

Materials and methods: We collected clinical data and DNA from the members of the family, and skin lesions were obtained from two patients with different phenotypes. Skin imaging examinations were performed. Whole-exome sequencing (WES) and Sanger sequencing were used to detect gene mutations.

Results: The characteristic features of granular layer degeneration in the two biopsies were verified via histological methods. The missense mutation c.1436T > C in KRT1 was detected in all nine patients.

Conclusion: This study demonstrates that AEI may present with different clinical phenotypes and that mutation analysis for suspected cases is necessary to obtain a precise diagnosis.

Keywords: KRT1 gene; annular epidermolytic ichthyosis (AEI); bullous congenital ichthyosiform erythroderma (BCIE); palmoplantar keratosis (PPK); whole-exome sequencing (WES).

MeSH terms

  • Adult
  • Biopsy
  • Child, Preschool
  • DNA Mutational Analysis
  • Dermoscopy
  • Exome Sequencing
  • Female
  • Humans
  • Hyperkeratosis, Epidermolytic / complications
  • Hyperkeratosis, Epidermolytic / diagnostic imaging*
  • Hyperkeratosis, Epidermolytic / genetics*
  • Hyperkeratosis, Epidermolytic / pathology
  • Keratin-1 / genetics*
  • Keratin-1 / metabolism
  • Keratoderma, Palmoplantar, Epidermolytic / complications
  • Keratoderma, Palmoplantar, Epidermolytic / genetics*
  • Male
  • Microscopy, Confocal
  • Mutation, Missense
  • Pedigree
  • Phenotype*
  • Skin / pathology


  • KRT1 protein, human
  • Keratin-1

Supplementary concepts

  • Ichthyosis, Cyclic, with Epidermolytic Hyperkeratosis