title: Association of β-defensin gene copy number variations with ankylosing spondylitis in Chinese population: A case-control study.
abstract: OBJECTIVE
  To explore the association of β-defensin gene copy number variations (CNVs) with ankylosing spondylitis (AS).
  
  
  METHODS
  In this study, 405 unrelated Chinese Han patients with AS and 401 unrelated healthy controls were enrolled. The copy numbers of DEFB4 gene (2 fragments) were measured by AccuCopy™ methods. The association of DEFB4 gene CNVs with AS susceptibility was analyzed by chi-square and logistic regression models. Besides, P values, odds ratio, and 95% confidence intervals (CIs) were used to estimate the effects of risk.
  
  
  RESULTS
  The range of DEFB4_1 CN was 0-7 and the range of DEFB4_2 CN was 1-8 both in patients and controls. P values of χ(2) trend test for the association of DEFB4_1 and DEFB4_2 with AS were 0.607 and 0.005, respectively. The results of DEFB4_2, compared with the individual having median 3 copies, those carrying ≤ 2-copies [OR = 0.68, 95%CI: (0.46, 0.99), P = 0.049; adjusted OR = 0.69, 95%CI(0.47, 1.03), P = 0.067.]; and those carrying ≥ 4-copies [OR = 0.62, 95%CI: (0.45, 0.86), P = 0.004; adjusted OR = 0.64, 95%CI: (0.46, 0.88), P = 0.006], were significantly associated with decreasing risk of AS. Univariate analysis showed that both DEFB4_1 and DEFB4_2 were associated with Bath AS Disease Activity Index or BASDAI. After adjusted by age, sex, and disease duration, the results changed little, which demonstrated that high copies may be linked with decrease in the risk of disease severity [OR = 0.71, 95%CI: (0.56, 0.90), P = 0.005; OR = 0.75, 95%CI: (0.60, 0.94), P = 0.013, respectively].
  
  
  CONCLUSIONS
  The CNs of DEFB4 gene may be associated with AS and involved in disease progression.
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Ning
authors.initials: N
authors.lastname: Ding
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Xiao
authors.initials: X
authors.lastname: Yang
authors.affiliation: b Anhui Medical Genetics Center in Anhui Medical College , Hefei , Anhui , China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Guoqi
authors.initials: G
authors.lastname: Cai
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Xia
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Dazhi
authors.initials: D
authors.lastname: Fan
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Li
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Yanting
authors.initials: Y
authors.lastname: Hu
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Xin
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.affiliation: c Department of Rheumatism and Immunity , the First Affiliated Hospital of Anhui Medical University , Hefei , Anhui , China.
authors.forename: Shengqian
authors.initials: S
authors.lastname: Xu
authors.affiliation: c Department of Rheumatism and Immunity , the First Affiliated Hospital of Anhui Medical University , Hefei , Anhui , China.
authors.forename: Jianhua
authors.initials: J
authors.lastname: Xu
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Zou
authors.affiliation: c Department of Rheumatism and Immunity , the First Affiliated Hospital of Anhui Medical University , Hefei , Anhui , China.|d Menzies Research Institute Tasmania, University of Tasmania , Hobart , Tasmania , Australia.
authors.forename: Changhai
authors.initials: C
authors.lastname: Ding
authors.affiliation: a Department of Epidemiology and Biostatistics , School of Public Health, Anhui Medical University , Hefei , Anhui , China.|c Department of Rheumatism and Immunity , the First Affiliated Hospital of Anhui Medical University , Hefei , Anhui , China.|d Menzies Research Institute Tasmania, University of Tasmania , Hobart , Tasmania , Australia.
authors.forename: Faming
authors.initials: F
authors.lastname: Pan
mesh_terms: D000328:Adult; D044466:Asian People / Q000235:genetics; D016022:Case-Control Studies; D056915:DNA Copy Number Variations; D018450:Disease Progression; D005260:Female; D018628:Gene Dosage; D020022:Genetic Predisposition to Disease; D006801:Humans; D008297:Male; D013167:Spondylitis, Ankylosing / Q000235:genetics*; D055815:Young Adult; D023083:beta-Defensins / Q000235:genetics*
chemical_list: D023083:beta-Defensins
keywords: Ankylosing spondylitis; case_control study; β-defensin copy number variation