Clinical and Phenotypic Characterization of Hereditary Transthyretin Amyloidosis (ATTRv) in Peruvian Population: First Case Series IMPAC-FE Study

Background: Hereditary transthyretin amyloidosis (ATTRv) is a rare multisystemic disease with variable phenotypic presentation, particularly underdiagnosed in Latin American populations. No data exists on ATTRv characteristics in Peru.Objective: To describe the demographic, genetic, and clinical characteristics of patients with ATTRv in Peru.Methods: Cross-sectional descriptive study of patients with confirmed ATTRv diagnosis attended at eight participating hospitals from March 2022 to December 2024. Patients were evaluated for clinical phenotype classification, neurological assessment (NIS, Norfolk QOL-DN), autonomic dysfunction (COMPASS-31, SUDOSCAN), cardiac assessment (echocardiography, Tc99m-PYP scintigraphy), and genetic characterization.Results: Twenty-three patients were included (69.6% male, median age 60 years, IQR 45-70). Three genetic variants were identified: Val142Ile (56.5%, n=13), Ala65Val (34.8%, n=8), and Val50Met (8.7%, n=2). Phenotypic distribution: preclinical 34.8% (n=8), mixed 39.1% (n=9), cardiac 21.7% (n=5), and neurological 4.3% (n=1). Notably, 77.8% of cardiac patients demonstrated Perugini grade 3 cardiac scintigraphy findings. The majority of patients (55.6%) reported minimal neuropathic symptoms (Norfolk QOL-DN <20).Conclusions: This first characterization of ATTRv in Peruvian population demonstrates a phenotypic distribution consistent with global registries, with high prevalence of Val142Ile variant and significant cardiac involvement. Early identification of carriers and presymptomatic patients represents a therapeutic opportunity given the availability of disease-modifying therapies. Genetic screening in asymptomatic relatives is recommended.