Delayed Diagnosis of Hereditary Transthyretin Cardiac Amyloidosis Presenting with Autonomic Neuropathy: A Case Report

Background: As a rare disease, cardiac amyloidosis (CA) has seen a deepening of epidemiological understanding, driven by advances in imaging and genetic testing, alongside drug development. However, the identification of suspected patients in the early stages remains inadequate. Case Presentation: Our 64-year-old patient carrying the rare transthyretin variant p.Gly67Val (legacy nomenclature Gly47Val) originally presented with lower limb numbness, resulting in prolonged follow-up at neurology outpatient clinics. Subsequently, unexplained hypotension led to hospital admission. The atypical early symptoms and inaccessibility of relevant tests delayed diagnosis and treatment. Discussion: As illustrated by this case, patients with CA referral to a specialist for further diagnosis and treatment typically occur when heart failure and conduction abnormalities have developed, a stage at which treatment outcomes are substantially limited. The p.Gly67Val variant ATTR-CA has been reported in about 20 carriers worldwide, with phenotypes ranging from neuropathy-dominant to cardiac-dominant disease; this case extends the emerging mixed phenotype of this spectrum. Conclusions: This case highlights the importance of recognizing extracardiac manifestations to reduce diagnostic delay in hereditary transthyretin cardiac amyloidosis.