The SCN9A loss of function results in inability to feel pain and the human clinical phenotypes are congenital insensitivity to pain (OMIM# 243000) and hereditary sensory autonomic neuropathy type IID (OMIM# 243000).2, 3, 25, 26, 27. The gene discussed is SCN9A; the disease is neuropathy, hereditary sensory and autonomic, type IId.