Human Cortical Organoids with a Novel SCN2A Variant Exhibit Hyperexcitability and Differential Responses to Anti-Seizure Compounds.

Mutations in ion channel genes have long been implicated in a spectrum of epilepsy syndromes. However, therapeutic decision-making is relatively complex for epilepsies associated with channelopathy. Therefore, in the present study, we used a patient-derived organoid model with a novel SCN2A mutation (p.E512K) to investigate the potential of utilizing such a model as a platform for preclinical testing of anti-seizure compounds. The electrophysiological properties of the variant Nav1.2 exhibited gain-of-function effects with increased current amplitude and premature activation. Immunofluorescence staining of patient-derived cortical organoids (COs) displayed normal neurodevelopment. Multielectrode array (MEA) recordings of patient-derived COs showed hyperexcitability with increased spiking and remarkable network bursts. Moreover, the application of patient-derived COs for preclinical drug testing using the MEA showed that they exhibit differential responses to various anti-seizure drugs and respond well to carbamazepine. Our results demonstrate that the individualized organoids have the potential to serve as a platform for preclinical pharmacological assessment.