Objective To systematically evaluate correlation between exon-1 (locus 49, A/G) and promoter (locus -318, C/T) polymorphisms of Chinese population cytotoxic T lymphocytes associated antigen-4 (CTLA-4) gene and Graves’ Disease (GD). Methods Relevant studies were electronically searched in CNKI, VIP, CBM, PubMed, EMbase and The Cochrane Library from 1980.1 to 2011.12. According to the inclusion and exclusion criteria, we selected and screened all case-control studies on the correlation between CTLA-4 exon -1 (locus 49, A/G) and promoter (locus -318, C/T) polymorphisms of Chinese population and GD. Then we extracted the data and assessed the methodological quality of the included studies. Meta-analysis was performed using RevMan 5.0 and STATA 12.0 software. Results (1) Ten studies on exon-1 were included. Results of meta-analyses showed that Chinese population with genotype G/G had a higher GD risk than those with genotype A/A (OR=3.38, 95%CI 2.07 to 5.51) and A/G (OR=1.72, 95%CI 1.31 to 2.25). Also, the allele G showed significant association with increased GD risk compared to the allele A (OR=1.87, 95%CI 1.44 to 2.41). (2) Five studies on promoter-318 were included. Results of meta-analyses showed that Chinese population with genotype T/T presented no increased relative risk compared to those with genotype C/C (OR=0.75, 95%CI 0.26 to 2.12) or C/T (OR=0.92, 95%CI 0.31 to 2.73). Meanwhile, the allele T showed no increased relative risk compared to the allele C (OR=0.83, 95%CI 0.61 to 1.12). Conclusion The allele G at the locus 49 of exon -1 of Chinese population is significantly associated with increased GD risks, yet the correlation between promoter –318 C/T polymorphism and GD hasn’t been demonstrated. Due to the limited quality and quantity of the included studies, more high-quality studies are needed to test the above conclusion.
Objective To systematically evaluate the correlation between type 2 diabetes mellitus (T2DM) in Chinese population and K121Q polymorphism in exon-4 of plasma cell glycoprotrin-1 (PC-1) gene. Methods The following databases such as CNKI, VIP, CBM, PubMed, EMbase, The Cochrane Library (Issue 3, 2012) and WanFang Data were searched to collect case-control studies on the correlation between T2DM and K121Q polymorphism in exon-4 of PC-1 gene. The retrieval time was from 1980 to 2012. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data and assessed the quality. Then the meta-analysis was conducted by using RevMan 5.0 and Stata 12.0 software, and the publication bias was analyzed by means of Egger’s linear regression. Results A total of 11 studies involving 1 637 T2DM patients and 1 730 healthy volunteers were included. The results of meta-analyses showed that, for Chinese population, the risk of T2DM was higher in those with K/Q genotype than K/K genotype (OR=1.84, 95%CI 1.19 to 2.85, P=0.006), in Q/Q+K/Q genotype than K/K genotype (OR=1.92, 95%CI 1.18 to 3.14, P=0.009), and also in allele Q than allele K (OR=1.83, 95%CI 1.16 to 2.89, P=0.010). Conclusion The K121Q polymorphism in exon-4 of PC-1 gene in Chinese population is significantly associated with T2DM. For the quantity and quality limitation of the included studies, this conclusion has to be further proved by more studies.