Abstract
Epidermolytic hyperkeratosis (EHK; OMIM 113800), or epidermolytic ichthyosis (EI), is a rare autosomal dominant skin disorder characterized by erythroderma and blistering at birth, which is replaced by progressive hyperkeratosis. In most cases, EHK/EI is due to dominant mutations in the genes encoding keratin 1 or keratin 10. A recessive form of EHK/EI has been described caused by truncating mutations in the KRT10 gene. Here, we report two male siblings with EHK/EI in whom we have identified a novel homozygous mutation, KRT10 c.1A>T. We discuss the importance of establishing the mode of inheritance in EHK. We also discuss the varying presentation of a ‘collodion baby’, and the differential diagnosis to consider. The histopathological and ultrastructural changes in both forms of EHK/EI have subtle differences that are detailed, and the importance of identifying these key features to target molecular analysis is further explained. These cases highlight the value of a dedicated skin genetics clinic with high-quality histopathological and electron microscopy services in the diagnosis of inherited skin conditions.
Acknowledgements
The authors are grateful to Ingrid Hausser, EM-Lab, Dermatological Department, University Heidelberg, Germany, for review of ultrastructure and for suggesting composition of aggregates.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
No writing assistance was utilized in the production of this manuscript.