Hereditary Transthyretin Amyloidosis (ATTRv) with Symmetric Paresthesia in All Limbs: A Case Report and Literature Review

We present the case of a 57-year-old male with a four-year history of progressive, symmetric paresthesia and numbness in all four limbs, associated with bilateral carpal tunnel syndrome. Past medical history included mild mitral regurgitation, concentric cardiomyopathy, bilateral knee os-teoarthritis, and a surgically treated pulmonary abscess. Family history was remarkable for bilat-eral carpal tunnel syndrome in his mother, who was subsequently found to carry the same patho-genic transthyretin mutation. Neurological examination revealed length-dependent sensory loss and areflexia, while electro-physiology confirmed axonal sensory polyneuropathy. Cardiac evaluation identified mild concen-tric left ventricular hypertrophy with preserved systolic function but impaired global longitudinal strain. Cardiac scintigraphy with ^99m^Tc-HDP demonstrated intense myocardial uptake (Peru-gini score 3). Genetic testing confirmed hereditary transthyretin amyloidosis (ATTRv) through the identification of the pathogenic p.I127V (c.379A>G) mutation in the heterozygous state. This case underscores the importance of considering ATTRv in patients presenting with progressive sensory axonal polyneuropathy and bilateral carpal tunnel syndrome, particular-ly in the context of a suggestive family history. It also highlights the complementary role of neu-rological and cardiac evaluation together with genetic confirmation in securing an early and accu-rate diagnosis. Finally, it emphasizes the value of cascade genetic screening for detecting asymp-tomatic carriers, which has direct implications for surveillance and family counseling.