title: CCL3L1 copy number variation and susceptibility to HIV-1 infection: a meta-analysis.
abstract: BACKGROUND
  Although several studies have investigated whether CCL3L1 copy number variation (CNV) influences the risk of HIV-1 infection, there are still no clear conclusions. Therefore, we performed a meta-analysis using two models to generate a more robust estimate of the association between CCL3L1 CNV and susceptibility to HIV-1 infection.
  
  
  METHODS
  We divided the cases and controls into two parts as individuals with CCL3L1 gene copy number (GCN) above the population specific median copy number (PMN) and individuals with CCL3L1 GCN below PMN, respectively. Odds ratios (ORs) with 95% confidence intervals (95% CIs) were given for the main analysis. We also conducted stratified analyses by ethnicity, age group and sample size. Relevant literatures were searched through PubMed and ISI Web of Knowledge up to March 2010.
  
  
  RESULTS
  In total, 9 studies with 2434 cases and 4029 controls were included. ORs for the main analysis were 1.35 (95% CI, 1.02-1.78, model: GCN ≤ PMN Vs. GCN > PMN) and 1.70 (95% CI, 1.30-2.23, model: GCN < PMN Vs. GCN ≥ PMN), respectively. Either in stratified analysis, statistically significant results can be detected in some subgroups.
  
  
  CONCLUSIONS
  Our analyses indicate that CCL3L1 CNV is associated with susceptibility to HIV-1 infection. A lower copy number is associated with an increased risk of HIV-1 infection, while a higher copy number is associated with reduced risk for acquiring HIV-1.
authors.affiliation: The State Key Laboratory of Genetic Engineering, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: SiJie
authors.initials: S
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Yao
authors.forename: DongLin
authors.initials: D
authors.lastname: Ding
authors.forename: HuanZhang
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D054405:Chemokine CCL3 / Q000378:metabolism; D019742:Chemokines, CC / Q000235:genetics* / Q000502:physiology*; D015331:Cohort Studies; D056915:DNA Copy Number Variations; D018628:Gene Dosage; D020022:Genetic Predisposition to Disease; D005838:Genotype; D015658:HIV Infections / Q000175:diagnosis* / Q000235:genetics*; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D007223:Infant; D016017:Odds Ratio
chemical_list: C492767:CCL3L1 protein, human; D054405:Chemokine CCL3; D019742:Chemokines, CC