Nonsynonymous single nucleotide polymorphisms in the complement component 3 gene are associated with risk of age-related macular degeneration: a meta-analysis

Nonsynonymous single nucleotide polymorphisms (SNPs) in complement component 3 (CC3) are associated with the risk of age-related macular degeneration (AMD), however, this association is not consistent among studies. To thoroughly address this issue, we performed an updated meta-analysis to evaluate the association between nine SNPs in the CC3 gene and AMD risk. A search was conducted of the PubMed database through 3rd Aug, 2014. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of associations. Based on the search criteria for manuscripts reporting AMD susceptibility related to CC3 in nine SNPs, 57 case-control studies from 22 different articles were retrieved. Significantly positive associations were found for the rs2230199 C/G SNP and AMD in the Caucasian population, as well as for the rs1047286 C/T SNP. Moreover, a relationship between the rs11569536 G/A SNP and AMD was detected. By contrast, a negative association was observed between rs2250656 A/G SNP and AMD risk. The present meta-analysis suggests that these four SNPs in the CC3 gene are potentially associated with the risk of AMD development. Further studies using larger sample sizes and accounting for gene-environment interactions should be conducted to elucidate the role of CC3 gene polymorphisms in AMD risk.