Abstract:Hereditary transthyretin amyloidosis is caused by pathogenic variants in the TTR gene, resulting in abnormal TTR (transthyretin) that deposits in organs. The c.424G>A p.Val142Ile (V142I) variant is the most common TTR variant in the United States, found almost exclusively in individuals of African ancestry, with a prevalence of 3% to 4% among that population. Although V142I hereditary transthyretin amyloidosis typically manifests as cardiomyopathy, other symptoms have been described, including carpal tunnel syndrome (CTS), neuropathy, and spinal stenosis (SS). The clinical impact of homozygous V142I variants remains unclear. In this study, we compare clinical phenotypes of patients with homozygous V142I to those of heterozygous carriers.