Transthyretin (TTR) amyloid cardiomyopathy (ATTR-CM) is becoming increasingly recognized because of population aging, advancements in the understanding of the disease pathobiology, and the potential benefits of emerging therapies.1,2 ATTR-CM is further classified into two subtypes by the presence or absence of TTR gene mutations: mutant ATTR-CM and wild-type ATTR-CM (ATTRwt-CM). This evidence concerns the gene TTR and cutaneous mastocytosis.