Amyloidosis (am-uh-loi-DO-sis) is a rare disease that occurs when an abnormal protein, called amyloid, builds up in your organs and interferes with their normal function. Amyloid isn’t normally found in the body, but it can be formed from several different types of protein.
https://www.mayoclinic.org/diseases-conditions/amyloidosis/symptoms-causes/syc-20353178

