The HCR gene on 6p21 is unlikely to be a psoriasis susceptibility gene

J Invest Dermatol. 2001 May;116(5):750-4. doi: 10.1046/j.0022-202x.2001.01323.x.

Abstract

The PSORS1 locus in the human major histocompatibility complex on 6p21 has been consistently associated with psoriasis in populations of diverse ethnicity. The HLA-C allele Cw*0602, located therein, has been found in up to 67% of psoriasis patients but is no longer considered a candidate gene in itself. The alpha-helix coiled-coil rod homolog gene (HCR, previously Pg8) is located 110 kb from the HLA-C gene, positioned between the CDSN and SC1 genes, within a region thought to harbor a psoriasis gene (PSORS1). We investigated the HCR gene for disease association by direct sequencing of nine polymerase chain reaction products amplified from a series of Swedish psoriasis patients and controls. We found that HCR is a very polymorphic gene with 25 polymorphisms in the open reading frame alone, of which 10 demonstrated disease association; however, the relationship between HCR polymorphisms and HLA-Cw*0602 indicates that HCR cannot truly be considered a likely candidate gene. We investigated Cw*0602 association while stratifying for HCR single nucleotide polymorphisms. We also investigated HCR single nucleotide polymorphism association with the disease while stratifying for the presence of Cw*0602. We found that whichever single nucleotide polymorphism that was stratified for, there was still a strongly significant Cw*0602 association with psoriasis; however, when we stratified for Cw*0602 presence, only one silent polymorphism showed significant association. In a recent similar study this polymorphism was actually found to be decreased in psoriasis individuals. Thus we conclude that HCR polymorphisms display association with psoriasis due to linkage disequilibrium with Cw*0602 and is, therefore, unlikely to be directly involved in the development of psoriasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Child
  • Chromosomes, Human, Pair 6 / genetics*
  • Conserved Sequence
  • Female
  • Genetic Predisposition to Disease / genetics*
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Male
  • Middle Aged
  • Polymorphism, Genetic
  • Proteins / genetics*
  • Proteins / physiology
  • Psoriasis / etiology*
  • Reference Values

Substances

  • CCHCR1 protein, human
  • Intracellular Signaling Peptides and Proteins
  • Proteins