title: Differential human leucocyte allele association between psoriasis and psoriatic arthritis: a family-based association study.
abstract: OBJECTIVE
  A recent population-based study identified several HLA alleles as conferring a risk for psoriatic arthritis (PsA) among patients with psoriasis. The authors aimed to confirm these results using a family-based association study.
  
  
  METHODS
  PsA probands, psoriasis probands and their first-degree family members were included. All participants were evaluated for the presence of psoriasis and inflammatory arthritis. HLA-B and -C genotyping was performed. The family-based association test was used to test for differences between PsA and psoriasis patients in transmission of candidate alleles from parents to offspring.
  
  
  RESULTS
  A total of 178 PsA and 30 psoriasis probands and 561 first degree family members were analysed. The following HLA alleles were over-transmitted to PsA compared with psoriasis: HLA-C*12 (p=0.005), HLA-B*38 (p=0.04), HLA-B*39 (p=0.03), HLA-B*27 (p=0.002).
  
  
  CONCLUSIONS
  HLA-B*27, HLA-B*38, HLA-B*39 and HLA-C*12 alleles are potential PsA-specific genetic markers among patients with psoriasis.
authors.affiliation: Center for Prognosis Studies in the Rheumatic Diseases,Toronto Western Hospital, University of Toronto Psoriatic Arthritis Clinic, Toronto, Canada.
authors.forename: Lihi
authors.initials: L
authors.lastname: Eder
authors.forename: Vinod
authors.initials: V
authors.lastname: Chandran
authors.forename: Fawnda
authors.initials: F
authors.lastname: Pellett
authors.forename: Sutha
authors.initials: S
authors.lastname: Shanmugarajah
authors.forename: Cheryl F
authors.initials: CF
authors.lastname: Rosen
authors.forename: Shelley B
authors.initials: SB
authors.lastname: Bull
authors.forename: Dafna D
authors.initials: DD
authors.lastname: Gladman
mesh_terms: D015535:Arthritis, Psoriatic / Q000235:genetics* / Q000276:immunology; D005192:Family Health; D005260:Female; D005787:Gene Frequency; D056726:Genetic Association Studies; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease; D005838:Genotype; D015235:HLA-B Antigens / Q000235:genetics*; D015236:HLA-C Antigens / Q000235:genetics*; D006650:Histocompatibility Testing; D006801:Humans; D015810:Linkage Disequilibrium; D008297:Male; D011159:Population Surveillance
chemical_list: D005819:Genetic Markers; D015235:HLA-B Antigens; D015236:HLA-C Antigens