True about senile systemic amyloidosis -

Amyloid of Aging Several well-documented forms of amyloid deposition occur with aging. Senile systemic amyloidosis refers to the systemic deposition of amyloid in elderly persons (usually in their 70s and 80s). Because of the dominant involvement and related dysfunction of the hea (typically manifesting as a restrictive cardiomyopathy and arrhythmias), this form also is called senile cardiac amyloidosis. The amyloid in this form is composed of normal transthyretin. In addition, another form typically affecting only the hea results from the deposition of a mutant form of TTR. Approximately 4%of the black population in the United States are carriers of the mutant allele, and cardiomyopathy has been identified in both homozygous and heterozygous patients.