Expression data from newborn Alox12b knockout mouse epidermis. Expression data from newborn Alox12b knockout mouse epidermis

Autosomal recessive congenital ichthyoses are a group of non-syndromic congenital keratinization disorders including harlequin ichthyosis, lamellar ichthyosis, and congenital ichthyosiform erythroderma with a total prevalence of 1:200,000. Affected individuals who are often born as collodion babies present with generalized scaling of the skin. This reflects a physical compensation for the defective cutaneous permeability barrier underlying all ichthyoses. Inactivity of 12R-lipoxygenase (12R-LOX) is a frequent cause of ARCI. Mice with targeted inactivation of the 12R-LOX gene Alox12b were established .Heterozygous mutant mice (Alox12b+/−) were bred with 129S6, and their heterozygous offspring were intercrossed to obtain homozygous mutant mice. Homozygous Alox12b knockout mice died within 3 hours after birth owing to defective skin barrier function. We used microarray to compare the gene expression profile in the epidermis of Alox12b-null mice with that of wildtype animals. Inactivation of Alox12b was associated with the upregulation of genes involved in keratinization, cholesterol biosynthesis, and Fc-epsilon receptor signaling. Overall design: Alox12b-null mice and wildtype control mice were sacrified immediately after birth and epidermis was harvested for RNA extraction and hybridization on Affymetrix microarrays.