FAMILIAL CARPAL-TUNNEL SYNDROME DUE TO AMYLOIDOGENIC TRANSTHYRETIN HIS-114 VARIANT

We studied two patients from a Japanese family with carpal tunnel synd rome (CTS). The biopsy samples obtained during CTS surgical release re vealed deposits of amyloid that stained with antihuman transthyretin ( TTR) antiserum. Single-strand conformation polymorphism analysis and s equence analysis of polymerase chain reaction (PCR)-amplified exons of the proband's TTR gene revealed st point mutation resulting in a subs titution of histidine for tyrosine at position 114. The mutation was c onfirmed by PCR-primer-induced restriction analysis. Our findings acco unt for clinical heterogeneity of TTR-derived amyloidosis, and suggest the importance of substitution itself for deposits of amyloid in CTS.