Association between genetic variation of complement C3 and the susceptibility to advanced age-related macular degeneration: a meta-analysis

BACKGROUND: The purpose of this study is to discuss whether genetic variants (rs2230199, rs1047286, rs2230205, and rs2250656) in the C3 gene account for a significant risk of advanced AMD. METHODS: We performed a meta-analysis using electronic databases to search relevant articles. A total of 40 case-control studies from 38 available articles (20,673 cases and 20,025 controls) were included in our study. RESULTS: In our meta-analysis, the pooled results showed that the carriage of G allele for rs2230199 and the T allele for rs1047286 had a tendency to the risk of advanced AMD (OR = 1.49, 95% CI = 1.39–1.59, P < 0.001; OR = 1.45, 95% CI = 1.37–1.54, P < 0.001). Moreover, in the subgroup analysis based on ethnicity, rs2230199 and rs1047286 polymorphisms were more likely to be a predictor of response for Caucasian region (OR = 1.48, 95% CI = 1.38–1.59, P < 0.001; OR = 1.45, 95% CI = 1.37–1.54, P < 0.001). Besides, pooled results suggested that the G allele of rs2230199 could confer susceptibility to advanced AMD in Middle East (OR = 1.62, 95% CI = 1.33–1.97, P < 0.001). CONCLUSION: In our meta-analysis, C3 genetic polymorphisms unveiled a positive effect on the risk of advanced AMD, especially in Caucasians. Furthermore, numerous well-designed studies with large sample-size are required to validate this conclusion. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12886-018-0945-5) contains supplementary material, which is available to authorized users.