[Two elderly cases of transthyretin amyloid polyneuropathy without a family history]

We report two cases of transthyretin familial amyloid polyneuropathy (ATTR-FAP) from non-endemic areas. Both cases showed chronic progressive distal limb numbness and weakness. Due to nonspecific symptoms, they were not diagnosed for a long period of time. A nerve conduction study revealed axonal neuropathy in the lower limbs and carpal tunnel syndrome. An echo test showed thickness of the left ventricle, one of the red flag symptom clusters of ATTR-FAP. Genetic analysis revealed a mutation in the transthyretin gene. In cases with chronic progressive neuropathy, it is important to consider a differential diagnosis of ATTR-FAP.