Genetic modifiers of epilepsy: A narrative review.

Epilepsy is a neurological disorder that shows strong genetic control on the timing and onset of symptoms and drug response variability. Some epilepsy syndromes have clear monogenic mutations but genes with control on the phenotype and severity of the disorder and drug sensitivity are present in the whole genetic profile. Genetic modifiers are not the cause of epilepsy but control significant networks such as synaptic plasticity and ion channels and neurodevelopment and neuroinflammation and therefore the reason why two individuals with the same primary mutations have different clinical courses. The review comprehensively examines the genetics of epilepsy to outline standard and minority genetic determinants and to distinguish between single-genetic and poly-genetic causes. It examines genetic modifiers and the mechanism by which they act and the control they exert on drug resistance and seizure risk and development of epilepsy and cognitive and behavioral problems. Alongside it explains how GWAS data with the help of epigenetics to identify significant modifying genes with control on neurotransmission and the immune response and metabolic pathways and ion channel regulation such as SCN1A and KCNQ2. The major functional mechanisms of genetic modifiers and the control they exert on network excitability and the control on the blood-brain barrier and neurodevelopmental pathways has been emphasized and explained in specific sections. The final section in this overview discusses the future possibility with precision medicine through genetic modifier-directed treatments and new drug development strategies and will develop tailored epilepsy treatment strategies.