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You are caring for a 65-year-old African American man who was recently told by a cardiologist that he likely has heart failure due to familial amyloidosis based on echocardiography. He has a strong family history of nonsystolic heart failure including his father and a brother who both died in their 60s. Which of the following statements regarding this patient’s condition is true?

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The correct answer is C. You answered A.

The answer is C.(Chap. 137) The most common form of familial amyloidosis is ATTRm in the updated nomenclature, caused by mutation of the abundant plasma protein transthyretin (TTR, also known as prealbumin). More than 100 TTR mutations are known, and most are associated with ATTR amyloidosis. One variant, V122I, has a carrier frequency that may be as high as 4% in the African American population and is associated with late-onset cardiac amyloidosis. The actual incidence and penetrance of disease in the African American population are the subject of ongoing research, but ATTR amyloidosis warrants consideration in the differential diagnosis of African American patients who present with concentric cardiac hypertrophy and evidence of diastolic dysfunction, particularly in the absence of a history of hypertension. DNA sequencing is the standard for diagnosis of ATTR. Without intervention, the survival period after onset of ATTR disease is 5–15 years. Standard treatment for nonsystolic heart failure is indicated. Orthotopic liver transplantation replaces the major source of variant TTR production with a source of normal TTR. Although liver transplantation can slow disease progression and improve chances of survival, it does not reverse sensorimotor neuropathy. Liver transplantations are most successful in young patients with early peripheral neuropathy; older patients with familial amyloidotic cardiomyopathy or advanced polyneuropathy often experience end-organ disease progression despite successful liver transplantation.


 

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