Successful Correction of Patient-Derived iPSCs for SCN8A-Related Developmental and Epileptic Encephalopathy Using an advanced CRISPR-Cas9 system

Abstract

Background: Mutations in the SCN8A gene are major contributors to developmental and epileptic encephalopathies (DEEs), leading to early-onset seizures and neurodevelopmental impairments. However, effective disease models and therapeutic strategies remain limited. Objectives: This study aimed to model SCN8A-related epilepsy using patient-derived induced pluripotent stem cells (iPSCs), perform genetic correction through prime editing, and compare the neurophysiological and pharmacological responses between mutant and corrected neurons. Methods: iPSCs were generated from a patient harboring the SCN8A c.4871T>G (p.Ile1624Ser) mutation and genetically corrected using prime editing. Neurons were differentiated by lentiviral expression of the transcription factors ASCL1, DLX2, and NGN2. Neural network activity was assessed using microelectrode array recordings, and the pharmacological effects of phenytoin and lacosamide were evaluated. ４０ Results: Patient-derived neurons exhibited hyperexcitability, frequent bursting, and hypersynchrony, whereas corrected neurons showed normalized electrophysiological activity. Prime editing effectively restored neural network function. The effects of phenytoin and lacosamide on network burst indices were more pronounced in corrected neurons, suggesting a tendency toward drug resistance in patient-derived neurons. Furthermore, complementary effects of the two drugs were observed, indicating the potential utility of combination therapy. Conclusion: The patient-specific iPSC-derived neuron model faithfully recapitulated SCN8A-related epilepsy. Genetic correction normalized pathological neuronal activity, and drug responsiveness was successfully evaluated using patient-derived cells, highlighting the potential of precision genome editing and personalized pharmacological strategies.