LAUSR

Inherited ichthyosis comprises a genetically heterogeneous group of disorders with skin dryness and scaling starting at birth or in childhood. Although ichthyoses are easy to recognize as a group of disorders, clinical subclassification and genotype– phenotype correlations are challenging because of the large number of genes and private diseasecausing variants. Frommherz et al. describe two families with autosomal dominant inheritance of a peculiar clinical phenotype consisting of childhoodonset acral lamellar ichthyosis (affecting the extremities). As shown in Figure 1, this was characterized by brown lamellar scaling without evidence of blistering, moulting or peeling. They found that this phenotype is caused by an amino acid substitution in the Cterminus of keratin 2. This molecular defect was not predicted by clinical or histologic features and the authors propose that it extends the spectrum of phenotypes associated with mutations in the gene for keratin 2. Acral lamellar ichthyosis may thus be genetically heterogeneous. Frommherz L, Komlosi K, Hewel C, et al. Acral lamellar ichthyosis with amino acid substitution in the Cterminus of keratin 2. J Eur Acad Dermatol Venereol 2023; 37:817822. doi: 10.1111/jdv.18719.