Diagnosis of familial amyloidotic polyneuropathy: isolation of variant prealbumin.

A novel, small-scale method was developed for detecting carriers of a prealbumin variant associated with type 1 familial amyloidotic polyneuropathy (FAP). Prealbumin isolated from plasma by a two-step preliminary chromatographic procedure was further separated into two peaks by reverse-phase high-performance liquid chromatography. The normal and variant prealbumins were identified by secondary ion mass spectrometry. The procedure is relatively simple, reliable, and applicable to the definitive diagnosis of FAP in affected patients and also as a preclinical test for the offspring of patients with FAP.