Diagnosis of familial amyloidotic polyneuropathy in France.

Two cases of familial amyloidotic polyneuropathy (FAP) in a French family are reported. Clinical onset was in the fifth and sixth decades with decreased sensation in the lower limbs followed by involvement of the upper extremities. Motor changes appeared later and evolved to restrict ambulation. Cardiac involvement with congestive heart failure and arrhythmias was the cause of death. DNA analysis was performed on ten members of this family. Restriction enzyme analysis of amplification products of exons 2, 3 and 4 of the prealbumin gene were negative for the methionine-30, alanine-60 and serine-84 mutations but positive for the tyrosine-77 mutation. The tyrosine-77 prealbumin mutation was first described in a family from Illinois with origin in Germany. The discovery of the tyrosine-77 gene in the family from Picardy may help to determine the origin of this disease and tell us if one mutation has been spread around the world, as we suspect, with many kindreds having the methionine-30 gene, or whether there have been separate spontaneous mutational events, perhaps a peculiarity of this site in the prealbumin gene.