Exploring the impact of somatic variant burden on seizures in focal cortical dysplasia

Somatic variants, or variants acquired post-zygotically, accumulate in all individuals over the course of their lifespan and can lead to a wide range of neurological disorders. Somatic variants arising during embryonic brain development are significant contributors to the genetic risk of epilepsy-associated focal malformations of cortical development and focal epilepsy without radiographic lesions. The propensity for any individual somatic variant to cause disease depends on its impact on the protein, as well as on the variant burden, which is the proportion of cells that carry the variant. The variant burden depends on the timing of the mutational event and on whether cells continue to divide after its occurrence.