Abstracts

Rationale: Pathogenic variants in the SCN2A gene, which encodes the voltage-gated sodium channel NaV1.2, are causative of a broad range of neurodevelopmental disorders, including epilepsy, autism spectrum disorder, and intellectual disability. Despite the growing interest in SCN2A-related disorders, the field lacks scalable, standardized functional screening assays to interpret the effects of variants on neuronal excitability and to test new therapeutic candidates in a human neuron context.

Methods: To address this need, we are developing an optical electrophysiology assay using stem cell-derived human neurons with engineered disease-associated SCN2A variants. Using the CellAxess platform from Cellectricon, the assay will integrate Ca2+-dye fluorescence imaging with electrical field stimulation of NGN2-derived excitatory neurons grown in 384-well plates. In parallel, using CRISPR/Cas9, we are introducing patient-specific SCN2A variants, including gain-of-function, loss-of-function, and mixed function variants, into an isogenic human pluripotent stem cell line.

Results: This assay system will support preclinical testing of multiple therapeutic modalities, such as small molecules, antisense oligonucleotides, and gene editing, tailored to specific variant effects and designed to restore normal neuronal excitability.

Conclusions: While initially focused on SCN2A, the assay framework is adaptable to other channelopathies, such as those involving SCN1A, SCN3A, and SCN8A, which share overlapping pathophysiology. This broader applicability positions the platform as a tool for advancing therapeutic development across a spectrum of ion channel–related disorders. Here, we discuss the progress made, through the concerted efforts of the non-profit organization the FamilieSCN2A Foundation and the biotech Cellectricon, in understanding and developing new treatments for SCN2A-related disorders.

Funding: Project is funded by The FamilieSCN2A Foundation 501(c)(3)