Bi-allelic inactivating mutations in SCN9A, which encodes the voltage-gated sodium channel (VGSC) NaV1.7, result in the striking clinical phenotype of congenital insensitivity to pain (CIP) (Cox et al., 2006, Goldberg et al., 2007). The gene discussed is SCN9A; the disease is hereditary sensory and autonomic neuropathy.