TTR and polyneuropathy: Hereditary amyloidosis TTR-related (hATTR) is a rare disease associated with several point mutations in the transthyretin (TTR) gene, determining abnormal aggregations of the transthyretin protein in different organs; hATTR is often misdiagnosed, as it is characterized by heterogeneous clinical features, including polyneuropathy, cardiomyopathy, vitreous opacity, and nephropathy, common to other diseases [1,2,3,4,5,6,7,8,9].