Some forms of TTR amyloidosis are inherited, meaning that the disease is carried in the genes and passed from one generation to the next. In this form of the disease, the TTR tetramer is destabilized by genetic alterations called mutations. ATTR caused by mutations can affect the heart, the digestive system and the nervous system.
When mutant ATTR affects the nervous system, it is called ATTR-PN or Familial Amyloid Polyneuropathy (FAP). When TTR amyloid is deposited in the nervous system, it can affect a person’s sensations, and eventually their ability to move normally. ATTR-PN also often affects the digestive system’s ability to work correctly, causing diarrhea and/or constipation.