Multisystemic manifestations of a rare Glu89Lys (p. Glu109Lys) transthyretin amyloidosis: a case report of an East Asian female

Transthyretin amyloidosis (ATTRv) presents with highly variable, multisystem phenotypes, complicating diagnosis. We describe a diagnostically challenging case of ATTRv caused by the rare Glu89Lys (p. Glu109Lys) variant in an East Asian female—the first reported instance in this ethnic group. The patient exhibited a complex multisystem phenotype spanning progressive axonal sensorimotor polyneuropathy with autonomic dysfunction, cerebral infarction, hypertrophic cardiomyopathy, vitreous opacities, and unexplained cachexia, culminating in a 4-year diagnostic odyssey. The lack of clinical suspicion delayed definitive diagnosis, ultimately achieved through combined tissue biopsy confirming amyloid deposits and targeted genetic sequencing confirming Glu89Lys variant. Our findings highlight the imperative for heightened clinical vigilance and early utilization of multimodal diagnostic strategies in suspected ATTRv cases.