TTR and cerebral amyloid angiopathy: Nevertheless, a number of patients with ATTR-FAP still remain undiagnosed and thus untreated because of diverse clinical presentations and various non-specific symptoms of the disease; especially in Japan, presence of diverse types of patients (e.g. early-onset Val30Met in endemic areas, late-onset Val30Met in non-endemic areas, non-Val30Met variants whose cardinal symptoms are cardiomyopathy, carpal tunnel syndrome, or cerebral amyloid angiopathy) often makes accurate diagnosis difficult [15, 16, 24, 43–45].