Association of skin barrier genes within the PSORS4 locus is enriched in Singaporean Chinese with early-onset psoriasis

J Invest Dermatol. 2009 Mar;129(3):606-14. doi: 10.1038/jid.2008.273. Epub 2008 Sep 11.


Psoriasis (OMIM#177900) is a common polygenic skin disorder affecting approximately 2% of the northern European population and 0.1% of the Han Chinese. Psoriasis patients suffer from chronic skin inflammation, manifested by erythematous scaly lesions. PSORS1-PSORS9 have been confirmed as psoriasis susceptibility loci in independent genetic studies on predominantly Caucasian populations, with psoriasis susceptibility loci (PSORS1, PSORS9) and additional loci at 9q33-34 and 2p22.3-11.2 reported in Han Chinese patients. In this study, we show the association of PSORS4 with psoriasis in Singaporean Chinese. Dense genotyping of single-nucleotide polymorphism-tagging candidate genes within the epidermal differentiation complex revealed significant association in the proximity of the involucrin gene (IVL); the strongest association was seen in early-onset psoriasis patients (P=0.0014). A follow-up genome-wide association screen localized the psoriasis susceptibility region to approximately 360 kb along chromosome 1 in the vicinity of IVL, small proline-rich region (SPRR) and proline-rich region 9 (PRR9) genes. The study of interactions between the causative variant(s) in this locus will provide insights into a possible role for epidermal barrier formation in the pathogenesis of psoriasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Age of Onset
  • China
  • Chromosomes, Human, Pair 2
  • Chromosomes, Human, Pair 9
  • Female
  • Genetic Predisposition to Disease*
  • Humans
  • Linkage Disequilibrium
  • Male
  • Polymorphism, Single Nucleotide
  • Psoriasis / diagnosis
  • Psoriasis / ethnology*
  • Psoriasis / genetics*
  • Singapore
  • Skin / metabolism*