Global Study Identifies Thousands of Genetic Variants Influencing Epilepsy Risk and Psychiatric Comorbidity Links

Oslo University researchers map the polygenic risk of epilepsy, identifying shared genetic variants with schizophrenia and the need for ancestral diversity.

By: AXL Media

Published: Mar 10, 2026, 4:26 AM EDT

Source: The information in this article was sourced from Genomic Press

Molecular Mapping of a Complex Neurological Landscape

The recently published synthesis in Genomic Psychiatry clarifies that epilepsy is not a singular entity but rather a diverse constellation of seizure disorders affecting approximately 50 million individuals worldwide. By integrating evidence from genome-wide association studies and whole-exome sequencing, researchers have illustrated a genetic framework that is far more complex than initial twin studies suggested. According to Dr. Olav B. Smeland, the Director of the research at the Centre for Precision Psychiatry, the findings transition the field from looking for single "epilepsy genes" toward understanding how thousands of variants contribute to the disease.

Quantifying Heritability Through Decades of Twin Data

Modern molecular methods have validated early observations from the 1930s regarding the hereditary nature of the condition. In a massive analysis of over 47,000 twin pairs, concordance rates for monozygotic twins reached 28 percent compared to only 7 percent for dizygotic twins. However, these patterns diverge sharply by subtype, as genetic generalized epilepsy shows a monozygotic concordance of 77 percent. This indicates that certain forms of the disorder are driven much more heavily by inherited genetic factors than others, with common variants carrying three times more weight in generalized cases than in focal epilepsy.

The Functional Convergence of Rare and Common Variants

One of the most striking insights from the review is the biological overlap between high-impact rare mutations and common genetic background noise. While severe monogenic epilepsies are linked to over a thousand specific genes, many of these same genes, such as SCN1A and SCN8A, also appear in studies of common polygenic risk. This suggests that both rare, high-effect deletions and the cumulative pressure of thousands of common variants utilize the same biological pathways. These pathways primarily govern ion channel function, synaptic excitability, and the delicate balance between excitatory and inhibitory signals in the brain.