SCN2A (antisense knockdown)

Class

antisense oligonucleotide (ASO) developed by Praxis Precision Medicines, designed to selectively decrease expression of SCN2A, the gene encoding the Nav1.2 voltage-gated sodium channel

Pathway

reduces SCN2A mRNA and Nav1.2 protein levels to counteract the gain-of-function sodium channel activity that causes SCN2A-related developmental and epileptic encephalopathy (SCN2A-DEE)

SCN2A is the gene encoding Nav1.2, a voltage-gated sodium channel that helps neurons generate and propagate electrical signals. In certain early-life epilepsies, referred to as SCN2A-related developmental and epileptic encephalopathy, specific mutations cause the channel to become overactive, a so-called gain-of-function change that leads neurons to fire excessively and produces seizures along with developmental impairment. One therapeutic strategy is to use an antisense oligonucleotide (ASO), a short synthetic strand of nucleic acid designed to bind the SCN2A messenger RNA (mRNA, the molecule that carries genetic instructions from DNA to the protein-making machinery) and mark it for degradation. By lowering the amount of mRNA available, the cell produces less Nav1.2 protein overall, which is intended to dampen the excess electrical activity driving seizures. This approach is distinct from conventional anti-seizure medicines because it targets the root molecular cause rather than broadly dampening neuronal excitability. Because Nav1.2 is also essential for normal brain function, the degree of reduction achieved matters considerably, and this class of mechanism is relevant more broadly to genetic epilepsies where a single gene's altered dosage or altered protein behavior drives disease.