Background: Evidence showed that the SCN1A IVS5N+5G>A polymorphism might be associated with susceptibility to epilepsy with febrile seizures (EFS), however, the published data were inconclusive. Therefore, a meta-analysis was performed to estimate the overall EFS risk with the polymorphism.
Methods: The PubMed and Medline were searched up to March, 2013 for studies on the association between SCN1A IVS5N+5G>A polymorphism and EFS risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by means of a genetic model free approach. The heterogeneity and sensitivity of each report and the publication bias were also performed. All the statistical analyses were done using the STATA 11.0 software.
Result: A total of 6 studies with 2719 cases and 2317 controls met the selection criteria. We found significant association between SCN1A polymorphism and EFS (A vs. G: OR=1.498, 95%CI=1.138-1.972; AA vs. GG: OR=2.292, 95%CI=1.620-3.243; AG vs. GG: OR=1.414, 95%CI=1.010-1.978; recessive model: OR=1.747, 95%CI=1.119-2.728 and dominant model: OR=1.730, 95%CI=1.259-2.376). When compared with the epilepsy without febrile seizure (EWFS), the subgroup analysis stratified by ethnicity showed that the SNP was significantly associated with EFS in Caucasian (A vs. G: OR=1.505, 95%CI=1.218-1.861; AA vs. GG: OR=2.081, 95%CI=1.358-3.189; recessive model: OR=1.715, 95%CI=1.273-2.310 and dominant model: OR=1.625, 95%CI=1.096-2.410), but not in Indian and Chinese. When applying Bonferroni correction (significance was set at 0.05/20), the Caucasian still has robust association with EFS and epilepsy.
Conclusion: The present meta-analysis suggests that SCN1A IVS5N+5G>A polymorphism is a risk factor of EFS and epilepsy, especially in Caucasian.
Keywords: 95% CI; 95% confidence interval; EFS; Epilepsy; Febrile seizures; Gene; HWE; Hardy–Weinberg equilibrium; Meta-analysis; OR; Polymorphism; SCN1A; SNP; epilepsy with febrile seizure; odds ratio; single nucleotide polymorphism.
© 2013.