Cardiomyopathy in a Japanese family with the Glu61Lys transthyretin variant: a new phenotype.

We report a Japanese family with transthyretin (TTR) amyloidosis caused by ATTRGlu61Lys that was associated with progressive cardiomyopathy, peripheral neuropathy, and bilateral carpal tunnel syndrome. Amyloidotic polyneuropathy in association with ATTRGlu61Lys was previously described in a Japanese family by Shiomi et al., (Biochem Biophys Res Commun 1993;194:1090-1096), and the main clinical features of that family were late-onset sensorimotor polyneuropathy and severe autonomic disturbance. However, there have been no descriptions of either cardiac involvement or carpal tunnel syndrome. The Japanese family, we present here, had severe cardiomyopathy as a cardinal symptom, which is a new phenotype of the TTR amyloidosis with ATTRGlu61Lys. This report, alongwith a previous one, demonstrates the clinical variety of TTR amyloidosis caused by ATTRGlu61Lys.