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

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 > Cin 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.