The Familial Amyloid Polyneuropathy (FAP) is a neurological disorder of autosomal dominant transmission. It is a hereditary and congenital disease that affects the peripheral nervous system (in their motor, sensory and autonomic aspects), among other organs. Its pathogenesis is related to the production of the plasmatic protein transthyretin by the liver (90%), retina and choroid plexus. In FAP patients, it is produced in its mutant form, i.e., there is a modification of the natural amino acid sequence of the protein, altering some of its properties. More specifically, these changes increase the propensity of amino acids to form protein aggregates that deposit in the nerves, causing damage.