We report an autopsy case of a pedigree of familial amyloidotic
polyneuropathy (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 abnormalities and serious
heart failure; the diagnosis of FAP (
ATTR Ser50Ile) was made on the basis of genetic, histochemical and immunohistochemical analysis. Six years after the initial symptoms, he died of
septic shock. Autopsy revealed suppurative
peritonitis, perforation of the sigmoid colon and marked systemic
amyloid deposition. The total amount of
amyloid deposited in the heart was greatly increased and was much lower in the thyroid gland and kidneys compared with
amyloid deposits in ordinary FAP (ATTR Val30Met).
Amyloid deposition in peripheral vessel walls was prominent, particularly in lymphatics and veins. His elder sister, 54 years old, started to develop
orthostatic 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 fibrils were deposited disproportionately and extended radially around microvessels.