title: Association between ERAP1 gene polymorphisms and ankylosing spondylitis susceptibility in Han population.
abstract: OBJECTIVE
  The present study was designed to investigate the relationship between endoplasmic reticulum amino peptidase 1 (ERAP1) gene polymorphisms and ankylosing spondylitis (AS) in Han population of Shaanxi province.
  
  
  METHODS
  100 AS patients and 100 healthy people were enrolled in present study as case and control groups respectively, and the control group was matched with the case group by age and gender. ERAP1 gene rs27434 and rs7711564 polymorphisms were test by TaqMan probe genotyping method. SHEsis software was used to operate linkage disequilibrium (LD) and haplotype analysis between the two single nucleotide polymorphisms (SNPs). χ(2) test was employed to compare the differences of the genotype, allele and haplotype frequencies between the case and control groups. Relative risk of AS was represented by odds ratios (ORs) and 95% confidence intervals (95% CIs).
  
  
  RESULTS
  In ERAP1 rs27434 and rs7711564 polymorphisms, the frequencies of AA and CC genotypes in case group were significantly higher compared to those in control group (P=0.036; P=0.039), and so were the frequencies of A and C alleles (OR=1.589, 95% CI=1.070-2.359, P=0.028; OR=1.535, 95% CI=1.021-2.308, P=0.050). Linkage disequilibrium test and haplotype analysis of the alleles of the two SNPs showed that the frequency of A-C haplotype was higher in case group than that in control group (P=0.005), which indicated that A-C might be the susceptible haplotype to AS.
  
  
  CONCLUSIONS
  ERAP1 gene rs27434 and rs7711564 polymorphisms may increase the risk of AS.
authors.affiliation: Department of Orthopedics, The Second Hospital Affiliated to Zhejiang University School of Medicine Hangzhou, Zhejiang, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, The Second Hospital Affiliated to Zhejiang University School of Medicine Hangzhou, Zhejiang, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Orthopedics, The Second Hospital Affiliated to Zhejiang University School of Medicine Hangzhou, Zhejiang, China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Orthopedics, The Second Hospital Affiliated to Zhejiang University School of Medicine Hangzhou, Zhejiang, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Gao
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D000626:Aminopeptidases / Q000235:genetics*; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D008875:Middle Aged; D015778:Minor Histocompatibility Antigens / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D013167:Spondylitis, Ankylosing / Q000235:genetics*; D055815:Young Adult
chemical_list: D015778:Minor Histocompatibility Antigens; D000626:Aminopeptidases; C464841:ERAP1 protein, human
keywords: ERAP1; ankylosing spondylitis; haplotype; polymorphism