A total of 26 significant epilepsy risk loci able to explain up to 90% of the genetic risk for certain types of epilepsy have been identified in a new study, which could help to pave the way for new treatments.
In the multi-ancestry genome-wide association study coordinated by the International League Against Epilepsy, researchers used a meta analysis to better understand the differences in the generic architectures between focal and generalised forms of the condition.
The analysis, published in the journal Nature Genetics, considered 4.9 million single-nucleotide polymorphisms (SNPs) in 52,538 controls and 29,944 people with epilepsy, of whom 16,384 had neurologist-classified focal epilepsy and 7,407 had genetic generalised epilepsy (GGE).
The team identified 26 genome-wide significant loci, of which 16 have not been reported previously and 19 of which were specific to GGE. In addition, there were 29 likely causal genes underlying these 26 loci. SNP-based analyses demonstrated how common variants explained between 39.6% and 90% of the genetic risk for GGE and its subtypes.
Commenting on these findings, Professor Gianpiero Cavalleri, professor of human genetics at the RCSI School of Pharmacy and Biomolecular Science, and deputy director of the SFI FutureNeuro Research Centre, which was involved in the research, said: ‘Gaining a better understanding of the genetic underpinnings of epilepsy is key to developing new therapeutic options and, consequently, a better quality of life for the over 50 million people globally living with epilepsy.
‘The discoveries we report on here could only be achieved through international collaboration on a global scale. We are proud of how the global community of scientists working to better understand the genetics of the epilepsies have pooled resources and collaborated effectively, for the benefit of people impacted the condition.‘
The term epilepsy describes a heterogeneous group of neurological disorders characterised by an enduring predisposition to generate unprovoked seizures. It has an annual cumulative incidence of 68 per 100,000 people.
The mechanism through which the different forms of epilepsy arise remain unclear although research in 2022 proposed hypertension as a potential cause. The role of genetics has also been uncertain with previous studies finding that only a limited proportion of cases of GGE can be explained by genetics.