title: Association of c3 gene polymorphisms with neovascular age-related macular degeneration in a chinese population.
abstract: OBJECTIVE
  The purpose of this study was to determine whether the genetic polymorphisms of complement factor 3 (C3) are associated with neovascular age-related macular degeneration (AMD) in the Chinese population.
  
  
  METHODS
  A total of 123 unrelated Chinese Han patients with neovascular AMD and 130 control subjects were recruited. Their six single-nucleotide polymorphisms (SNPs) in the C3 gene, one in the complement factor H (CFH) gene and two in the complement factor B (CFB) gene were characterized. Their genotypes, allele frequencies, and odds ratios were analyzed.
  
  
  RESULTS
  The G allele of the C3 IVS2 rs2250656, but not other tested C3 SNPs of rs2230205, rs10411506, rs2230199, rs339392, and rs163913, was significantly associated with a reduced risk for AMD in the Chinese population (OR 0.605, 95% CI 0.39-0.93, p = 0.023), even after adjusting for age, gender, smoking status, CFH rs1061170, CFB rs4151667, and CFB rs641153 allele status (OR 0.58, 95% CI 0.35-0.96, p = 0.033). However, the C3 haplotype of A-A-C-A-T-T was identified as a statistically significant risk factor for neovascular AMD (OR 1.41, 95% CI 1.02-1.94). Furthermore, the C allele of the CFH rs1061170, but not the CFB rs4151667 and rs641153, was significnatly associated with increased risk for AMD (OR 3.09, 95% CI 1.55-6.15, p < 0.001).
  
  
  CONCLUSIONS
  The G allele of C3 IVS2 rs2250656 may be a significantly protective factor for neovascular AMD in the Chinese population. This, together with low MAF of C3 R102G, may be partially responsible for the low prevalence of AMD in the Chinese population.
authors.affiliation: The People Eye Center, Peking University People's Hospital, Beijing, China.
authors.forename: Xue-Ting
authors.initials: XT
authors.lastname: Pei
authors.forename: Xiao-Xin
authors.initials: XX
authors.lastname: Li
authors.forename: Yong-Zhen
authors.initials: YZ
authors.lastname: Bao
authors.forename: Wen-Zhen
authors.initials: WZ
authors.lastname: Yu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yan
authors.forename: Hui-Jun
authors.initials: HJ
authors.lastname: Qi
authors.forename: Tong
authors.initials: T
authors.lastname: Qian
authors.forename: Hong-Xiang
authors.initials: HX
authors.lastname: Xiao
mesh_terms: D000368:Aged; D044466:Asian People / Q000235:genetics*; D020256:Choroidal Neovascularization / Q000235:genetics* / Q000517:prevention & control; D003176:Complement C3 / Q000235:genetics*; D011415:Complement Factor B / Q000235:genetics; D017242:Complement Factor H / Q000235:genetics; D017931:DNA Primers; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D008268:Macular Degeneration / Q000235:genetics* / Q000517:prevention & control; D008297:Male; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: C493495:CFH protein, human; D003176:Complement C3; D017931:DNA Primers; D017242:Complement Factor H; D011415:Complement Factor B