The authors genotyped three groups of Caucasians: those with PsA, those with psoriasis without arthritis (PsC) and healthy controls for the rs20541 and rs848 IL13 single nucleotide polymorphisms (SNPs).
Both SNPs were found to be highly associated with susceptibility to PsA (rs1800925 ptrend = 6.1 × 10(-5) OR 1.33, rs20541 ptrend = 8.0 × 10(-4) OR 1.27), but neither SNP was significantly associated with susceptibility to PsV.