The Gerstmann-Straussler-Scheinker syndrome is a disease transmitted b
y autosomal dominant inheritance characterized by nonsense mutations o
f the prion protein associated with specific neuropathological lesions
-multicentric amyloid plaques labelled by antibodies directed against
the prion protein. This restrictive definition justifies retaining the
name of Gerstmann-Straussler-Scheinder syndrome and excludes observat
ions of hereditary prion diseases without multicentric amyloid plaques
and sporadic forms with multicentric plaques. The main feature of the
se different observations is their polymorphous clinical presentation
which varies not only between families with the same mutation but also
with a given family. The underlying mechanisms of the phenotypic poly
morphism remain uncertain.