Congenital Insensitivity to Pain (CIP) is a rare disorder that is characterized by the inability to perceive pain. It is caused by bi-allelic inactivating mutations in the SCN9A gene, which encodes the pore-forming alpha-subunit of the nerve voltage-gated sodium channel (Na(v)1.7). Patients with CIP are unable to feel pain from noxious stimuli, including heat, but all other peripheral somatosensory modalities function normally. Often anosmia is present as an additional feature. We reported a patient with CIP caused by compound heterozygous SCN9A mutations: a novel in-frame deletion of exon 7 and a novel frameshift mutation. The identification of these mutations expands the spectrum of mutations associated with CIP.
- congenital insensitivity to pain