Congenital insensitivity to pain (CIP) comprises a group of rare genetic disorders caused by mutations in genes essential for pain sensing in humans. Among these, Marsili syndrome is caused by a dominant point mutation in the transcription factor ZFHX2, and it is characterized by markedly reduced sensitivity to noxious heat, mechanical injury, while other functions remain intact. this project aims to establish the first integrated, system-level characterization of Marsili syndrome by combining human sensory phenotyping with neurophysiological and molecular analyses. The study will be conducted in two sessions of approximately 4 hours each, 24 hours apart from each other