Significance of the amyloidogenic transthyretin Val 122 Ile allele in African Americans in the Arteriosclerosis Risk in Communities (ARIC) and Cardiovascular Health (CHS) Studies

Heterozygosity for the amyloidogenic TTR V122I mutation is relatively common in community-dwelling African Americans. Before the age of 65 years, the allele has no discernible impact on cardiac function or mortality. After the age of 70 years, carriers show a higher frequency of congestive failure and greater mortality with more echocardiographic evidence suggestive of cardiac amyloidosis, findings consistent with age-dependent clinical penetrance of this autosomal dominant gene.