Introduction: PSORS4 is a susceptibility locus for psoriasis vulgaris (PsV), a common inflammatory, hyperproliferative skin disorder. Recently, a deletion of two late cornified envelope (LCE) genes within epidermal differentiation complex on chromosome 1 was shown to be enriched in 1,426 PsV patients, suggesting compromised barrier function in deletion carriers. We subsequently confirmed this genetic association in a German cohort.
Methods: In order to investigate whether this variant also predisposes to psoriatic arthritis (PsA), we genotyped this deletion and three SNPs in strong linkage disequilibrium with it in a case-control cohort of 650 patients and 937 control individuals of German origin.
Results: LCE deletion frequency did not significantly differ between PsA patients and controls (65.0% vs. 65.5%). Similarly, no evidence for association to the three SNPs was observed.
Discussion: This is the first non-HLA risk factor predisposing only to skin-type of psoriasis supporting the concept of partially overlapping, but different etiological factors underlying skin and joint manifestations.