The association of SCN1A polymorphisms with epilepsy and drug resistance: a systematic review and meta-analysis

Epilepsy is one of the most common neurological afflictions worldwide, with one-third of patients exhibiting resistance to treatment. It has been speculated that the polymorphisms of the sodium channel alpha subunit 1 (SCN1A) gene are associated with both the occurrence of epilepsy and its resistance to treatment. The aim of this study is to systematically review the literature and conduct meta-analyses revealing the associations of the SCN1A polymorphisms with epilepsy and resistance to treatment. We conducted a search of Pubmed, Web of Science, and Scopus, and if more than two studies investigated a polymorphism, odds ratios for association with epilepsy and/or resistance to treatment were calculated in three allelic, homozygous, and recessive genetic models. The initial search yielded 4106 items, and a total of 64 articles met the final inclusion criteria. With respect to the occurrence of epilepsy, the rs2298771 polymorphism was revealed to be negatively associated in the recessive model, while the associations of other polymorphisms were not statistically significant. With regard to resistance to treatment, rs2298771 was revealed to be positively associated across all three models, and rs10167228 was positively associated in the allelic and homozygous models, but not the recessive model. Other polymorphisms were not shown to be associated with resistance to treatment. In conclusion, we demonstrated that the rs2298771 polymorphism had a significant and negative association with the occurrence of epilepsy. Furthermore, rs2298771 and rs10167228 polymorphisms had positive associations with resistance to treatment. Further studies are needed to explore these associations among other polymorphisms.