Sisters with No Pain, No Tears: A Report of a New Variant of Hereditary Sensory and Autonomic Neuropathy (Type IX) Caused by a Novel SCN11A Mutation.

Lack of pain sensation in children involves a rare group of heritable disorders; hereditary sensory and autonomic neuropathy (HSAN). Till date, eight types of HSAN have been described depending on the clinical phenotype and the underlying gene mutation. We report a new variant of HSAN (Type IX) in two siblings (of Indian origin) with a novel mutation of SCN11A gene and a distinct clinical phenotype.