RESUMEN
Amyloidosis which represents neuropathy due to the systematic amyloid fibril deposits has two types; the non-hereditary primary amyloid polyneuropathy (PAP) and the familial amyloidotic polyneuropathy (FAP). The clinical manifestations of the two diseases are similar, but the FAP is an autosomal dominant disease and has better prognosis than the PAP. The PAP is a rare disease which displays relatively rapid progress and severe hypoalbum-inemia. We report a 50-year-old male patient admitted due to weight loss, orthostatic hypotension, and the unique sensory changes which pain and temperature sensations are decreased on the periumbilical area and lower extremity. The patient shows severe proteinuria, hypoalbuminemia and generalized edema. There are definite amyloid deposits in the biopsied sural nerve in the light and polarizing microscope and amyloid fibrils in the electron microscope. But no abnormality of transthyretin gene is found in this patient and one cousin. The transthyretin DNA analysis is useful for the differential diagnosis of PAP and FAP.