Genetic Variants in Epidermal Differentiation Complex Genes as Predictive Biomarkers for Atopic Eczema, Allergic Sensitization, and Eczema-Associated Asthma in a 6-Year Follow-Up Case-Control Study in Children

Abstract

Atopic eczema is the most common chronic inflammatory skin disease of early childhood and is often the first manifestation of atopic march. Therefore, one challenge is to identify the risk factors associated with atopic eczema that may also be predictors of atopic disease progression. The aim of this study was to investigate the association of SNPs in hornerin (HRNR) and filaggrin-2 (FLG2) genes with childhood atopic eczema, as well as other atopic phenotypes. Genotyping for HRNR and FLG2 was performed in 188 children younger than 2 years of age, previously screened for the FLG null mutations, and followed at yearly intervals until the age of 6. We demonstrated that risk variants of HRNR rs877776[C] and FLG2 rs12568784[T] were associated with atopic eczema, allergic sensitization, and susceptibility to the complex phenotype-asthma plus eczema. These effects seem to be supplementary to the well-known associations for FLG mutations and may be modulated by gene-gene interactions. Additionally, in children with eczema, these genetic variants may also be considered, along with FLG mutations, as predictive biomarkers for eczema-associated asthma. In conclusion, our results indicate that genetic variants in the epidermal differentiation complex gene could contribute to the pathogenesis of atopic eczema and progression to subsequent allergic disease.

Keywords: asthma; atopic eczema; atopic march; biomarkers; filaggrin; filaggrin-2; genetic association; hornerin; mutations; skin barrier.