Hereditary transthyretin amyloidosis is a rare progressive systemic disease. We describe
a physically active 46-year-old man who presented with dyspnoea on exertion. An echocardiogram
showed increased left ventricular wall thickness and diastolic dysfunction, but normal
systolic function. The QRS voltage on ECG was normal. The patient was diagnosed with
hypertrophic cardiomyopathy, and several years passed before establishment of the
accurate diagnosis of hereditary transthyretin amyloidosis caused by the rare mutation
ATTR Phe33Leu, previously described in only five case reports. Further investigation
revealed neuropathy and nephropathy, and the patient developed severe heart failure.
The patient is treated with tafamidis, has undergone heart transplantation and is
currently planned for liver transplant. Hereditary transthyretin amyloidosis is likely
underdiagnosed, especially in patients presenting with cardiomyopathy. A discrepancy
between the left ventricular mass indicated by echocardiogram and that on ECG is an
important indicator of amyloidosis, as is involvement of multiple organs.
