Table 1.
Types of human sodium channels (NaCh) α and β subunits and their tissue distribution.
| Gene | Chromosome | Protein | Uniprot code* | Tissue expression |
|---|---|---|---|---|
| α-subunits | ||||
| SCN1A | 2q24.3 | Nav1.1 or α1.1 | P35498 | Cell bodies of central neurons, T-tubules in myocytes axon initial segments |
| SCN2A | 2q24.3 | Nav1.2 or α1.2 | Q99250 | Central neurons, mainly localizated in unmyelinated and premyelinated axons |
| SCN3A | 2q24.3 | Nav1.3 or α1.3 | Q9NY46 | Cell bodies of central neurons, cardiac myocytes |
| SCN4A | 17q23.3 | Nav1.4 or α1.4 | P35499 | Skeletal muscles |
| SCN5A | 3p21-22 | Nav1.5 or α1.5 | Q86V90 | Cardiac myocytes, immature and denervated skeletal muscles, certain brain neurons |
| SCN8A | 12q13 | Nav1.6 or α1.6 | Q9UQD0 | Somatodendritic distribution in output neurons of cerebellum, cerebral cortex, hippocampus; Purkinje cells in cerebellar granule cell layer, astrocytes, Schwann cells, axon initial segments, dorsal root ganglia, nodes of Ranvier in peripheral and central nervous systems, T-tubules in cardiac myocytes |
| SCN9A | 2q24 | Nav1.7 or α1.6 | Q15858 | Dorsal root ganglia neurons, sympathetic neurons, Schwann cells, neuroendocrine cells |
| SCN10A | 3p22.2 | Nav1.8 or α1.8 | Q9Y5Y9 | Dorsal root ganglia neurons, human heart, intracardiac neurons |
| SCN11A | 3p22.2 | Nav1.9 or α1.9 | Q9UI33 | C-type neurons in dorsal root ganglia |
| SCN7A | 2q24.3 | NavX | Q01118 | Dorsal root ganglia neurons, hippocampus, thalamus, cerebellum, median preoptic nucleus, circumventricular organs, Peripheral nervous system (PNS), heart, skeletal muscle, uterus |
| β -subunits | ||||
| SCN1B | 19q13.1 | SCN1b or β1 | Q07699 | Ubiquitous: central and peripheral neurons, glia, skeletal and cardiac muscles |
| SCN1B | 19q13.1 | SCN1bB or β1B | Cortical neurons, Cerebellar Purkinje cells, Deep cerebellar nuclei, Ventral horn neurons, Dorsal root ganglia neurons, peripheral nerves | |
| SCN2B | 11q23 | SCN2b or β2 | Q5U0K8 | Central and peripheral neurons, glia, cardiac muscles |
| SCN3B | 11q23.3 | SCN3Bor β3 | Q9NY72 | Central and peripheral neurons, adrenal glands, kidney |
| SCN4B | 11q23.3 | SCN4b or β4 | Q8IWT1 | Central and peripheral neurons, glia, skeletal and cardiac muscles |
Modified from Patiño et al. (2009) and Catterall (2012).