TTR and Familial transthyretin-related amyloidosis: Hereditary transthyretin amyloidosis (ATTRv) is a rare, systemic, progressive, and life-threatening disease caused by the misfolding of the transthyretin (TTR) protein and consequent formation of amyloid fibrils, which deposit in organs and tissues throughout the body and disrupt their ability to function [1, 2].