title: Association of ERAP1, but not IL23R, with ankylosing spondylitis in a Han Chinese population.
abstract: OBJECTIVE
  The results of a recent genome-wide association study have shown that ERAP1 and IL23R are associated with ankylosing spondylitis (AS) in Caucasian populations from North America and the UK. Based on these findings, we undertook the current study to investigate whether single-nucleotide polymorphisms (SNPs) covering the genes ERAP1 and IL23R are associated with AS in a Han Chinese population.
  
  
  METHODS
  A case-control study was performed in Han Chinese patients with AS (n = 527) and controls (n = 945) from Shanghai and Nanjing. All patients met the modified New York criteria for AS. The Sequenom iPlex platform was used to genotype cases and controls for 21 tag SNPs covering IL23R and 38 tag SNPs covering ERAP1. Statistical analysis was performed using the Cochran-Armitage test for trend.
  
  
  RESULTS
  Multiple SNPs in ERAP1 were significantly associated with AS (for rs27980, P = 0.0048; for rs7711564, P = 0.0081). However, no association was observed between IL23R and AS (for all SNPs, P > 0.1). The nonsynonymous SNP in IL23R, rs11209026, widely thought to be the primary AS-associated SNP in IL23R in Europeans, was found not to be polymorphic in Chinese.
  
  
  CONCLUSIONS
  Our results demonstrate that genetic polymorphisms in ERAP1 are associated with AS in Han Chinese, suggesting a common pathogenic mechanism for the disease in Chinese and Caucasian populations, and that IL23R is not associated with AS in Chinese, indicating a difference in the mechanism of disease pathogenesis between Chinese and Caucasian populations. This may result from the fact that rs11209026, the nonsynonymous SNP in IL23R, is not polymorphic in Chinese patients, providing further evidence that rs11209026 is the key polymorphism associated with AS (and likely inflammatory bowel disease and psoriasis) in this gene.
authors.affiliation: Princess Alexandra Hospital, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Stuart I
authors.initials: SI
authors.lastname: Davidson
authors.forename: Xin
authors.initials: X
authors.lastname: Wu
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.forename: Meng
authors.initials: M
authors.lastname: Wei
authors.forename: Patrick A
authors.initials: PA
authors.lastname: Danoy
authors.forename: Gethin
authors.initials: G
authors.lastname: Thomas
authors.forename: Qing
authors.initials: Q
authors.lastname: Cai
authors.forename: Linyun
authors.initials: L
authors.lastname: Sun
authors.forename: Emma
authors.initials: E
authors.lastname: Duncan
authors.forename: Niansong
authors.initials: N
authors.lastname: Wang
authors.forename: Qinghong
authors.initials: Q
authors.lastname: Yu
authors.forename: Anlong
authors.initials: A
authors.lastname: Xu
authors.forename: Yonggui
authors.initials: Y
authors.lastname: Fu
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Brown
authors.forename: Huji
authors.initials: H
authors.lastname: Xu
mesh_terms: D000626:Aminopeptidases / Q000235:genetics*; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D016022:Case-Control Studies; D002681:China; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics; D005838:Genotype; D006801:Humans; D015778:Minor Histocompatibility Antigens; D009656:North America; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D018123:Receptors, Interleukin / Q000235:genetics*; D013167:Spondylitis, Ankylosing / Q000208:ethnology* / Q000235:genetics*; D006113:United Kingdom; D044465:White People / Q000208:ethnology / Q000235:genetics
chemical_list: C515500:IL23R protein, human; D015778:Minor Histocompatibility Antigens; D018123:Receptors, Interleukin; D000626:Aminopeptidases; C464841:ERAP1 protein, human