Assignment of a human voltage-dependent sodium channel α-subunit gene (scn6a) to 2q21-q23

Voltage-dependent sodium (Na[sup +]) channels are responsible for the initial membrane depolarization that occurs during action potential generation in most electrically excitable cells. These ion channel proteins exist as heteromultimeric complexes of a large ([approximately]260 kDa) [alpha]-subunit and one or two smaller ([approximately]33-38 kDa) [beta]-subunits. A multigene family consisting of at least five structurally related Na[sup +] channel [alpha]-subunit isoforms has been defined. Three brain Na[sup +] channel isoform genes are clustered together on proximal mouse chromosome 2 and compose part of a linkage group that exhibits synteny with a region of human 2q. We now have localized the gene encoding the hNa 2.1 Na[sup +] channel isoform to this same general region of chromosome 2 (2q21-q23) by a combination somatic cell hybrid mapping and chromosome microdissection-polymerase chain reaction. This information may facilitate the identification of inherited diseases affecting Na[sup +] channel function. 10 refs., 1 tab.