Sodium ion channels allow the flow of positively charged sodium ions (Na⁺) and are highly selective for the transport of sodium ions across cell membranes. They play an essential role in the electrical signaling of nerve and muscle cells and regulating cell volume.

Mutations in genes that encode for sodium ion channels can lead to a variety of diseases, with the key one being:

1. Epilepsy
2. Chronic pain
3. Cardiac arrhythmias