[Protein and DNA sequencing analyses of transthyretin in familial amyloidotic polyneuropathy].

Recent advances in protein chemistry and the molecular biology of amyloid proteins have led to knowledge of the primary etiology of FAP. The protein product of the gene in question was identified, then the chromosomal location and point mutations in the gene were determined. Diagnosis of the disorder now can be made at the protein and DNA levels. Recombinant techniques for producing variant proteins have been established and a transgenic mouse that carries the mutated gene have been produced. Liver transplantation, a curative therapy for FAP, has been used for some patients. Procedures for the diagnosis of TTR-related FAP and the elucidation of TTR abnormality are summarized as follows: TTR-related FAP should be considered when biopsies of abdominal fat, the gingiva, stomach, rectum and sural nerves demonstrate amyloid deposits that are specifically stained by anti-TTR antiserum. Analysis of the TTR gene based on RFLP and single strand conformational polymorphism is useful for detecting the genetic mutations identified so far. Even when no known mutations have been detected, protein sequence analysis of serum TTR and nucleotide sequence analysis of the TTR gene have shown new variant TTRs. These advances in FAP research herald a new era in our investigation of the molecular biology of inherited neuropathy.