SYNDROMIC VIGNETTES IN ANAESTHESIA Southern African Journal of Anaesthesia & Analgesia- May 2005 66

and familial dysautonomia with congenital insensitivity to pain ably affects development, as well as maintenance of neurons, because there is neuropathological and clinical progression.1 Inherited autonomic neuropathies are a rare group of disorders as-sociated with sensory dysfunction. As a group they are termed the "hereditary sensory and autonomic neuropathies " (HSAN). Classifi-cation of the various autonomic and sensory disorders is ongoing.3 Phenotypic expression varies and overlap between different entities makes the classification difficult. In recent years, identification of spe-cific genetic mutations for some disorders has aided both the diagno-sis and classification. The best known and most intensively studied of the HSANs are familial dysautonomia (Riley-Day syndrome or HSAN type III) and congenital insensitivity to pain with anhidrosis (HSAN type IV) Diagnosis of the HSANs depends primarily on clinical ex