Sodium channel protein type 2 subunit alpha (Na_v1.2) (Na_v1.2)

The Sodium channel protein type 2 subunit alpha (Na_v1.2), encoded by the SCN2A gene on chromosome 2q24.3, is a voltage-gated sodium channel primarily expressed in the central nervous system, particularly in pyramidal neurons of the cortex and hippocampus. It forms a transmembrane glycoprotein complex with beta subunits, mediating sodium influx upon membrane depolarization to initiate and propagate action potentials essential for neuronal signaling. Na_v1.2 is prominent at axon initial segments in early development, later restricting to unmyelinated axons and potentially aiding dendritic backpropagation in mature neurons. Pathogenic mutations in SCN2A cause gain-of-function effects linked to early infantile epilepsy responsive to sodium channel blockers, or loss-of-function effects associated with autism spectrum disorder, intellectual disability, and later-onset seizures where blockers may worsen symptoms. This genetic risk factor underlies SCN2A-related neurodevelopmental disorders, with functional assays guiding precision therapies amid challenges like isoform-specific expression and regulatory interactions.

Other names

Sodium voltage-gated channel alpha subunit 2Nav1.2SCN2A (gene name)

Voltage-dependent sodium ion permeability mediation, Channel blockade to reduce neuronal hyperexcitability in gain-of-function states