The prevalence of ATTR-CM may be substantially higher than these numbers,18 especially given that the prevalence of HF in the US is around 6.2 million per the Centers for Disease Control and Prevention.19 Approximately 50% of people with HF have a preserved EF (HFpEF), and transthyretin deposition is found on autopsy in about 25% of those over 80 years of age with HFpEF. The gene discussed is TTR; the disease is hydrops fetalis.