The association of genetic polymorphisms with cerebral palsy: a meta-analysis

AIM The aim of ourmeta-analysis was to summarize quantitatively the association of genetic polymorphisms with cerebral palsy (CP). METHOD We identified 16 studies on the association of genetic polymorphisms with CP in Pubmed, Elsevier Science Direct, Chinese Biomedical Literature Database, Chinese National Knowledge Infrastructure, and Wanfang. Eleven of these studies (involving a total of 2533 cases and 4432 controls) were used in the current meta-analysis. A study was included if (1) it was published up to September 2010 and (2) it was a case-control study. We excluded one study of family members because the analysis was based on linkage considerations. Meta odds ratios and 95% confidence intervals based on fixed-effectsmodels or random-effects models were dependent on Cochran's Q statistic. We examined the relationship between alleles, as well as genotypes and susceptibility to CP. RESULTS Meta-analysis was performed for 17 genetic polymorphisms: apolipoprotein E (epsilon 2, epsilon 3, epsilon 4), methylenetetrahydrofolate reductase (MTHFR) (rs1801133), coagulation factor II (rs1799963]), coagulation factor V (rs6025), coagulation factor VII (rs5742910/rs6046), interleukin-6 (IL-6) (rs1800795), endothelial nitric oxide (rs1800779/rs1799983/rs3918226), fibrinogen beta-polypeptide (rs1800790), plasminogen activator inhibitor 1 (rs1799768/rs7242), TNF-beta lymphotoxin alpha precursor (rs1041981), adducin 1 (alpha) (rs4961), ADRB2 (rs1042714), and tumour necrosis factor alpha (rs1800629). We found a significant association between CP and IL-6 (rs1800795) [C vs G: odds ratio (OR) 1.79, 95% confidence interval (CI) 1.44-2.22, p < 0.001; CC+GC vs GG: OR 1.72, 95% CI 1.29-2.29, p=0.002; CC vs GG+GC: OR 2.17, 95% CI 1.52-3.09, p < 0.001], but no other genetic polymorphisms. INTERPRETATION This meta-analysis demonstrated that CP is associated with the genetic polymorphism IL-6 (rs1800795).