A case of late onset cardiac amyloidosis with a new transthyretin variant (lysine 92)

A new transthyretin (TTR) variant (lysine 92), which causes late onset card iac amyloidosis, is described in a 71-year-old man. The patient at first ha d syncope due to ventricular tachycardia and was admitted our hospital. Typ ical findings of cardiac amyloidosis were observed by echocardiography, and a diagnosis of systemic amyloidosis was made by rectal biopsy. The man die d approximately 3 years and 6 months after first admission, with gradually worsening congestive heart failure. Pathological examination showed promine nt amyloid deposits in the heart and the vascular wall of many organs inclu ding the liver, pancreas, kidney, lung, and gastrointestinal tracts. Amyloi d protein of transthyretin type was indicated by immunohistochemical study, and DNA sequencing identified a novel mutation in the transthyretin gene e ncoding 92 glutamine --> lysine. A polymerase chain reaction-induced mutati on restriction analysis with a mismatched antisense primer showed that the patient was heterozygous for the TTR Lys92 allele. HUM PATHOL 32:237-239. C opyright (C) 2001 by W.B. Saunders Company.