The function of Ensembl gene identifier ENSG00000136531 (SCN2A, sodium voltage-gated channel alpha subunit 2) is as follows. Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na(+) ions may pass in accordance with their electrochemical gradient (PubMed:1325650, PubMed:17021166, PubMed:28256214, PubMed:29844171). Implicated in the regulation of hippocampal replay occurring within sharp wave ripples (SPW-R) important for memory (By similarity). {ECO:0000250|UniProtKB:B1AWN6, ECO:0000269|PubMed:1325650, ECO:0000269|PubMed:17021166, ECO:0000269|PubMed:28256214, ECO:0000269|PubMed:29844171}.