Prevalence of FAP is 1 per 1 million inhabitants. They have been reported until 1990s' in four endemic areas North of Portugal, Sweden, Japan and Majorca. In these areas, diagnosis is facilitated because of the stereotypical presentation : a length-dependent polyneuropathy with predominant involvement of thermal and pain sensations and autonomic dysfunction, early onset in the third decade and a predominant Met30 TTR mutation. Positive family history is frequent 85% (one of the parents is affected). Diagnosis requires detection of TTR mutation by molecular biology (blood sample) and characterization of amyloid deposit on labial salivary gland biopsy.