In FBD a point mutation, while in FDD a decamer duplication insertion, abolishes the stop codon of the BRI2 gene [23, 30, 31, 77, 80, 81] resulting in elongated precursor proteins, from which the amyloid peptides amyloid-Bri (ABri) and amyloid-Dan (ADan) are released in FBD and FDD, respectively. The gene discussed is ITM2B; the disease is ADan amyloidosis.