Technetium pyrophosphate myocardial uptake and peripheral neuropathy in a rare variant of familial transthyretin (TTR) amyloidosis (Ser23Asn): a case report and literature review

Abstract

We report the fourth case of transthyretin amyloidosis (ATTR) Ser23Asn in a 41-year-old Ecuadorian male. He has a pedigree that spans seven generations and involves 24 family members who suffered early cardiac death. Salient presenting symptoms were fatigue, shortness of breath, and peripheral neuropathy. The diagnosis of cardiac amyloid was confirmed by immunohistochemical staining of an endomyocardial biopsy, genotyping and by technetium pyrophosphate (^99mTc-PYP) scintigraphy, which remains to be established as a reliable tool to visualize myocardial amyloid involvement in patients with the Ser23Asn transthyretin (TTR) variant. The patient underwent successful combined heart and liver transplant. We add to the current ATTR literature that in patients with the rare Ser23Asn mutation, peripheral nerve in addition to cardiac involvement can occur and ^99mTc-PYP scintigraphy can be used as an imaging modality to visualize myocardial amyloid.

Keywords::

• Transthyretin amyloid
• ATTR
• Ser23Asn
• technetium pyrophosphate
• peripheral neuropathy

Acknowledgments

We thank Dr. Charles Marboe for his assistance with immunohistochemical staining of endomyocardial biopsies.

Declaration of interest: The authors report no conflicts of interest as pertain to the article’s preparation or subject matter.