The Neuropathy In Hereditary Transthyretin Amyloidosis: A Narrative Review

Hereditary transthyretin amyloidosis (ATTRv) is a condition with adult-onset caused by mutation of transthyretin (TTR) gene and characterized by extracellular deposition of amyloid fibrils in tissue, expecially in peripheral nervous system (PNS) and heart. The PNS involvement lead to a rapidly progressive and disabling sensory-motor axonal neuropathy. Although awareness among neurologist raised in last years thank to new treatment options, ATTRv is frequently misdiagnosed and thus correct diagnosis can be delayed by several years. This review aims to draw the history and features of polyneuropathy in ATTRv based on pathological and electrophysiological correlates. We assessed original articles and case reports based on their relevance to ATTRv neuropathy and we included those appropriated for the scheme of this narrative review. The amyloid fibrils deposit initially in ganglia causing an axonal neuropathy without amyloid deposits in distal segments (eg, sural nerve biopsy). Over time, amyloid fibrils spread along the nerve leading to some demyelinating features in a context of severe axonal loss. This review highlithed how the features of neuropathy changes based on type of ATTRv (early vs late onset) and stage of disease.