Systematic review of genome-wide association studies (GWAS) of epilepsy identifies common risk variants and associated genes.

Abstract

Objective: The aetiology of epilepsy is known to have genetic contributions, yet results from genome-wide association studies (GWAS) have not always been consistent. We undertook a systematic review in order to identify risk variants for epilepsy.

Methods: This systematic review was conducted in accordance with the PRISMA protocol. The quality of each of the studies was evaluated using the Q-Genie tool.

Results: A total of 79 SNPs, located in 64 genes, were significantly associated with epilepsy at the genome-wide level. The majority of the variants were intronic and intergenic, with SCN1A as the most widely reported gene involved across studies. Two SNPs, rs2292096 and rs149212747, linked respectively to focal epilepsy (FE) and status epilepticus, were exclusively identified in individuals of Asian ancestry, alongside an Asian-exclusive synonymous variant (rs3782886) in BRAP and a missense variant (rs671) in ALDH2.

Conclusions: Genes, which encode for ion and transport channels, transcription factors, ubiquitin ligase and transporter proteins were identified as potentially involved in the aetiology of epilepsy. The review identified one missense and one synonymous variant which deserve further exploration. Future research should include populations of more diverse ancestries, which may reveal unique epilepsy-associated genes.