Amyloid neuropathy with transthyretin mutations: overview and unique Ala97Ser in Taiwan

Familial amyloid polyneuropathy (FAP) is a major etiology in differential diagnosis of symmetric axonalform polyneuropathy, but had been considered an unusual disease in Taiwan. We have reviewed the pathology of nerve biopsies and sequenced the entire 4 exons of transthyretin (TTR), the most common genetic mutation of FAP. Our studies indicated that the mutation of TTR at Ala97Ser (TTR Ala97Ser) was a new mutation only reported in ethnic Taiwanese, and this mutation accounted for the most frequent etiology of adult-onset pan-modality (involving motor, sensory, and autonomic components of peripheral nerves) polyneuropathy with the pathology of axonal degeneration type. Over the past 10 years, there have been advancements in the management of FAP due to TTR mutations: (1) symptomatic treatments of dyaautonomia, especially orthostatic hypotension, and (2) therapies with liver transplantation and small molecules to reduce or stabilize TTR.