What is NaV1.7?
There are 9 different subtypes of voltage-gated Na channels. Of particular interest is the selective expression of a tetrodotoxin-sensitive voltage-gated Na channel, namely NaV1.7, in sensory neurons. Loss of function of this channel is associated with the condition of congenital insensitivity/indifference to pain. Conversely, gain of function of the channel underlies the clinical condition of erythromelalgia, which is characterized by severe ongoing, burning pain of the distal extremities. Lidocaine and other local anesthetics block all voltage-gated Na channels. Ideally, a selective NaV1.7 antagonist could provide pain relief with a much better therapeutic window.