Association between SCN1A polymorphism and carbamazepine responsiveness in epilepsy: A meta-analysis

Background: Carbamazepine (CBZ) is one of most used antiepileptic drugs. However, CBZ-resistance is common in patients with epilepsy, and genetic polymorphisms can influence antiepileptic drug responsiveness. The association between the polymorphisms rs3812718 and rs2298771 of theSCN1A gene and risk of resistance to CBZ in epilepsy remains controversial. To further assess the pooled association, we conducted an updated metaanalysis to investigate the contribution of the two SCN1A single nucleotide polymorphisms that may confer CBZ-resistance. Methods: We searched PubMed, Embase, and Web of Science databases for eligible studies. All the case-controlled studies related to the association of the SCN1A polymorphisms, rs3812718 and rs2298771, with CBZ-resistance in epilepsy were included. Pooled odds ratios (OR) as well as the corresponding 95 % confidence intervals (CI) were determined. Results: A total of eight out of 255 articles were used to assess the association between SCN1A and CBZ-resistance in epilepsy. We found a significant association between rs2298771 (GG vs GA + AA; OR 3.19, 95 % CI 1.27 8.02, p > 0.05, I2 = 0) and CBZ-resistance in epilepsy patients of Asian ethnicity. No association was observed between the rs3812718 polymorphism and CBZ responsiveness. Conclusion: Our results indicate that Asian patients with epilepsy and the SCN1A rs2298771 polymorphism, especially the GG genotype, may be at risk of CBZ-resistance.