Association between complement factor I gene polymorphisms and the risk of age-related macular degeneration: a Meta-analysis of literature.

Aim: To systematically review the association between complement factors I (CFI) polymorphisms and age-related macular degeneration (AMD) and to explore whether CFI polymorphisms are associated with AMD.

Methods: Meta-analysis of articles published from 1995 to January 2015 of articles involved with AMD and polymorphisms of the CFI gene. Eligible data were pooled in a Meta-analysis, analyzing using STATA software (version 12.0), Review Manager (version 5.2) and different models based on the heterogeneity of effect sizes. Egger's test, Begg's rank correlation methods were used to evaluate for publication bias.

Results: Thirteen articles were eligible, describing two loci polymorphisms of the CFI gene (of which 12 articles focus on rs10033900T>C and 3 articles focus on rs2285714C>T). For rs10033900T>C, the results of our study revealed that having a mutant allele C, TC, CC and TC+CC was associated with a decreased risk of AMD in all population groups studied (C versus T models, OR=0.84, 95%CI: 0.72-0.99, P=0.04; TC versus TT models OR=0.89, 95%CI: 0.88-0.99, P=0.04; CC versus TT models, OR=0.76, 95%CI: 0.60-0.98, P=0.03; TC+CC versus TT models, OR=0.81, 95%CI:0.65-0.99, P=0.04). We found that C allele were related to lower AMD risk in the Caucasian population by subgroup analysis, but there was no association with AMD under the allele and genotypes comparison in Asian studies. For rs2285714 C>T, the TC, TT genotypes contributed to a higher risk of AMD, compared with the CC carriers and TC+CC (OR=1.34, 95%CI: 1.09-1.63, P=0.004; OR=1.50, 95%CI: 1.25-1.80, P<0.0001).

Conclusion: This Meta-analysis suggests that CFI rs10033900T>C and rs2285714C>T polymorphisms may contribute to AMD.