Human VGSC α-subunits
| Gene | α-Subunit | Human Chromosomal Location | Primary Tissue Expression | Tetrodotoxin Sensitivity |
|---|---|---|---|---|
| SCN1A | Nav1.1 | 2q24 | Neurons of the central nervous system | TTX-sensitive |
| SCN2A | Nav1.2 | 2q23-24 | Neurons of the central nervous system | TTX-sensitive |
| SCN3A | Nav1.3 | 2q24 | Neurons of the central nervous system | TTX-sensitive |
| SCN4A | Nav1.4 | 17q23-25 | Skeletal muscle | TTX-sensitive |
| SCN5A | Nav1.5 | 3p21 | Cardiac, denervated skeletal muscle | TTX-resistant |
| SCN8A | Nav1.6 | 12q13 | Neurons of the central nervous system | TTX-sensitive |
| SCN9A | Nav1.7 | 2q24 | Neurons of the peripheral nervous system | TTX-sensitive |
| SCN10A | Nav1.8 | 3p22-24 | Neurons of the dorsal root ganglia | TTX-resistant |
| SCN11A | Nav1.9 | 3p21-24 | Neurons of the dorsal root ganglia | TTX-resistant |
| SCN6/7A | NaX | 2q21-23 | Uterus, astrocytes, hypothalamus | N/A |