Paroxysmal Extreme Pain Disorder - Cause

Cause

The voltage-gated sodium channel Na_V1.7 is expressed in nociceptive and sympathetic neurons, where it aids in action potential creation and regulation. The mutations in this gene that have received study all alter the channel's ability to inactivate. Sodium channel inactivation is vital for the proper cessation of action potentials. The decreased inactivation caused by these mutations, then, is expected to cause prolonged action potentials and repetitive firing. Such altered firing will cause increased pain sensation and increased sympathetic nervous system activity, producing the phenotype observed in patients with PEPD.