Ablation of dysmorphic neurons is a safe and effective treatment for focal cortical dysplasia II.

Focal cortical dysplasia type II (FCDII) is a leading cause of refractory epilepsy in children, yet treatment options remain limited. The most frequent genetic cause of FCDII is mosaic and somatic variants in genes of the phosphatidylinositol 3-kinase (PI3K)-protein kinase B (AKT)-mammalian target of rapamycin (mTOR) pathway, leading to hyperactivation of mTOR signaling. The presence of dysmorphic neurons (DNs) resulting from hyperactive mTOR signaling is critical for the development of epilepsy in FCDII. One critical therapeutic challenge and opportunity for FCDII is to selectively eliminate DNs. Here, we developed two strategies to specifically ablate DNs in FCDII mouse models, and the results demonstrate that DN ablation is sufficient to both prevent and eliminate epilepsy in mice. Moreover, the associated neurobehavioral abnormalities were also reversed following treatment. Therefore, our study provides proof-of-concept evidence that DN ablation is a highly promising approach for curing FCDII in the future.