Practice of Hereditary ATTR Amyloidosis in Non-endemic Areas of Japan

OBJECTIVE: Hereditary ATTR (ATTRv) amyloidosis was once an incurable disease; however, in recent years, disease-modifying therapies, such as tafamidis and patisiran, have become available. We herein report the medical care situation in an ATTRv amyloidosis non-endemic area of Japan. METHODS: We confirmed the information in the medical records of our department and analyzed the data retrospectively. PATIENTS: Patients with ATTRv amyloidosis who were treated in our department between 2010 and 2021 were included. RESULTS: A total of 15 ATTRv amyloidosis cases (8 men and 7 women) were treated in our department during the study period; 9 patients had a family history, and the transthyretin V30M (p.V50M) gene mutation was present in 66% of cases. The average age of the onset was 57 years old, with 73% of the initial symptoms being dysesthesia and 13% being autonomic dysfunction. Ten patients were treated with tafamidis and nine with patisiran. Although it took a long time to start treatment among our experienced cases, there were some cases in which treatment could be introduced relatively early. CONCLUSION: ATTRv amyloidosis is treatable and should be included in the differential diagnosis of neuropathy so that it can be diagnosed early and introduced into treatment. In the near future, the presymptomatic diagnosis of ATTRv amyloidosis and genetic counseling will become more important.