Congenital insensitivity to pain (CIP) comprises rare genetic disorders characterized by the absence of perception of noxious stimuli from birth. Despite their shared clinical phenotype, CIP syndromes arise from distinct molecular defects that differentially affect nociceptor development, ion channel function, and autonomic regulation. Pathogenic variants in genes, including NTRK1, SCN9A, and PRDM12, define key mechanisms of human nociception. NTRK1-associated CIP with anhidrosis results from disrupted nerve growth factor signaling, leading to loss of small-diameter sensory fibers, impaired thermoregulation, and autonomic instability. SCN9A- and PRDM12-associated forms affect sodium channel function or nociceptor development; autonomic involvement is generally less prominent but requires assessment in each patient. This narrative review synthesizes the genetic and neurodevelopmental basis of CIP syndromes and examines their implications for perioperative management and the development of analgesics. By correlating genotype-specific mechanisms with clinical phenotypes, CIP syndromes help to identify key components of nociceptive pathways. These rare disorders highlight molecular targets for precision analgesia and demonstrate how genetic characterization may guide perioperative risk assessment and the development of targeted pain therapies.