Abstract 17058: Phenotypically Sex Differences in Transthyretin Amyloidosis V122I Mutation Patients
Introduction: Hereditary transthyretin amyloidosis (ATTR) is an autosomal dominant disease, in which destabilized transthyretin protein misfolds and deposits in tissue leading to organ dysfunction. The most common mutation in the United States, transthyretin valine 122 isoleucine (V122I), primarily affects African Americans and is historically associated with cardiomyopathy phenotype in men. Recent studies have described a mixed V122I phenotype with both cardiomyopathy and polyneuropathy. Sex differences in V122I presentations have yet to be examined. Methods: We identified 38 ATTR patients treated at The Ohio State University with genetic testing demonstrating V122I mutation (31.6% female). Clinical data was analyzed for cardiac and nerve involvement including cardiac biopsy or nuclear pyrophosphate scan, echocardiography - interventricular septal thickness (IVSd), posterior wall thickness (PWd), ejection fraction (EF), and electromyography (EMG). Cohorts were divided by sex. Unpaired t-tests were used to calculate statistics. Asymptomatic patients (n=2) were not included. Results: In women with V122I ATTR, the clinical phenotypes were polyneuropathy (75%) and cardiomyopathy (25%) with symptom onset most often in the fourth or fifth decade of life. In men with V122I ATTR, the most common phenotypes were cardiomyopathy (52%) and mixed cardiomyopathy/polyneuropathy (48%) with symptom onset in the seventh and eighth decades of life. In affected individuals, EMG data revealed generalized neuropathy with reduced or absent sural nerve sensory response. Carpal tunnel syndrome, often due to thickening of the transverse ligament, was more common in men than women (84% versus 36%). Men had significant cardiac differences compared to women with thickened ventricles (IVSd 19.9 mm vs 12.5 mm, p<0.001 and PWd 17.3 mm vs 12.1 mm, p<0.001) and decreased ejection fraction (40% versus 55%, p=0.008). Conclusion: Based on our cohort, female ATTR V122I patients present predominantly with polyneuropathy phenotype at a younger age, and males present with predominantly cardiovascular or mixed phenotype. Recognizing these different sex phenotypes in ATTR V122I will improve diagnosis and treatment of patients.