The lack of genetic association between the most common Crohn's disease alleles of the CARD15 gene and psoriatic joint disease on large cohorts of white patients does not support a recently claimed role for CARD15 as the first non-MHC susceptibility gene in the pathogenesis of psoriatic arthritis, but confirms and extends previous studies in the case of psoriasis vulgaris.
This particular insertion mutation in the NOD2 gene does not appear to contribute to the genetic susceptibility of psoriasis vulgaris, PPP or guttate psoriasis.