Are BIC (miR-155) polymorphisms associated with eczema susceptibility?

Eczema (nomenclature according to the World Allergy Organization (1), also referred to as atopic dermatitis, OMIM#603165) is one of the most common chronic inflammatory skin disorders. Twin studies indicate a strong genetic contribution to the development of eczema, and genetic linkage analyses have identified several chromosomal regions and candidate genes linked to eczema susceptibility (2).The discovery of microRNAs (miRNAs) has raised the question whether not only classical genes but also non-coding RNA genes may be involved in the patho -genesis of eczema. miRNAs are short (20–22 nt), non-coding RNAs, which suppress the activity of their target genes at the post-transcriptional level (3). miRNAs have important regulatory roles in virtually all biological functions, including development, cell proliferation, immune response and tumourigenesis. miRNA research has been a subject of interest in the dermatology field recently, and intriguing results have demonstrated the importance of miRNAs in skin biology (4–8). We have shown that skin from patients with eczema and psoriasis has an altered expression pattern of miRNAs compared with healthy skin (4, 9). However, the question still remains whether genes coding for miRNAs may be genetically associated with eczema susceptibility. In searching for genes that are differentially expres-sed in eczema and healthy skin, we recently performed a large-scale gene-expression study (10). As shown in Fig. 1a, the