Diagnosis of familial amyloidotic polyneuropathy by recombinant DNA techniques.

An amino acid substitution of Met for Val at position 30 of plasma prealbumin is known to be closely related to heredo-familial amyloidotic polyneuropathy(FAP). As a first step in development of a direct method for diagnosis of the disease, cDNA for normal human prealbumin was cloned and its nucleotide sequence was determined. Our results showed that the nucleotide substitution responsible for the Val----Met change results in formation of new restriction sites for BalI and NsiI. By Southern blot hybridization analysis, the expected restriction sites were actually detected in the prealbumin locus of patients. Thus, a method was developed for diagnosis of the disease presymptomatically and prenatally.