The study aims, by generating a large registry of patients with ATTR amyloidosis, including data at diagnosis and during follow up, to describe the natural history of ATTR amyloidosis in a real-world setting and to define and validate prognostic models, response criteria applicable at any point of the disease. The registry will also be used for data sharing and to allow the possibility of a close collaboration amongst the amyloidosis experts of the ARTC and all the physicians around the Country involved in the diagnosis and management of systemic amyloidosis. Thanks to the online registry, the diagnostic facility of the ARTC will be made available to requesting physicians.