[Proposals for the early diagnosis of late-onset hereditary ATTR amyloidosis in ‍nonendemic areas in Japan].

Late-onset hereditary ATTR (ATTRv) amyloidosis in nonendemic areas takes long periods of time to diagnose in many cases because the clinical symptoms are varied and nonspecific with the family history often unidentifiable. In recent years, disease-modifying therapies have been available for ATTRv amyloidosis, and early diagnosis is increasingly needed. The diagnosis of ATTRv amyloidosis usually requires histological confirmation of the amyloid deposition, although the amyloid detection rate largely depends on the experience, knowledge, and skill of the physician who performs the biopsy. It is important to consider ATTRv amyloidosis as a differential disease in idiopathic polyneuropathy. If ATTRv amyloidosis is strongly suspected, it is acceptable to perform TTR genetic testing prior to histological examination after a thorough differential diagnosis has been made.