Amyloid polyneuropathy caused by wild-type transthyretin.

INTRODUCTION Amyloidosis derived from transthyretin (TTR) molecules is typically caused by mutations of the TTR gene. METHODS We describe an elderly patient with a severe length-dependent polyneuropathy that unexpectedly proved to be caused by wild-type transthyretin amyloidosis. RESULTS The diagnosis was made by muscle biopsy, because no amyloid deposits were found in the biopsied nerve segment. Most cases of wild-type transthyretin amyloidosis occur in elderly patients with cardiomyopathy, but a few cases of polyneuropathy have been reported. CONCLUSIONS This entity is especially noteworthy in light of emerging treatment options for hereditary transthyretin amyloidosis, which are likely to also be beneficial in wild-type disease.