Familial amyloidotic polyneuropathy (ATTR Ser50Ile): the first autopsy case report

We report an autopsy case of a pedigree of familial amyloidotic polyneuropa thy (FAP) with a mutation of isoleucine-50 transthyretin (ATTR Ser50Ile), A 47-year-old man started developing severe diarrhea and weight loss at age 41 years, followed by urinary incontinence, autonomic-nervous-system abnorm alities and serious heart failure: the diagnosis of FAP (ATTR Ser50Ile) was made on the basis of genetic, histochemical and immunohistochemical analys is. Six years after the initial symptoms, he died of septic shock. Autopsy revealed suppurative peritonitis, perforation of the sigmoid colon and mark ed systemic amyloid deposition. The total amount of amyloid deposited in th e heart was greatly increased and was much lower in the thyroid gland and k idneys compared with amyloid deposits in ordinary FAP (ATTR Val30Met). Amyl oid deposition in peripheral vessel walls was prominent, particularly in ly mphatics and veins. His elder sister, 54 years old, started to develop orth ostatic hypotension at age 49 years, followed by dysesthesia, diarrhea and severe congestive heart failure. Endomyocardial biopsy revealed severe TTR- amyloid deposition; ultrastructural examination demonstrated that amyloid f ibrils were deposited disproportionately and extended radially around micro vessels. These characteristic patterns of systemic amyloid deposition and d istinct clinical manifestations, especially in the cardiovascular system, a re considered to be a characteristic feature of ATTR Ser50Ile amyloidosis.