Gerstmann-Sträussler-Scheinker syndrome (GSS)
A rare familial form of progressive dementia inherited in an autosomal dominant manner due to a mutant prion gene on chromosome 20pter-p12. Degeneration of the nervous system usually starts in the fourth or fifth decade of life with slowly developing dysarthria (difficulty speaking) and cerebellar ataxia (wobbliness) and later the progressive dementia become evident. Death usually occurs within 10 years of the onset of symptoms. First described in 1936 by the Austrian neurologists Josef Gerstmann (1887-1969), Ernst Sträussler (1872-1959), and I. Scheinker. The syndrome is now known to be a form of transmissible spongiform encephalopathy (TSE), a prion disease. Also called cerebral amyloidosis with spongiform encephalopathy, cerebellar ataxia with progressive dementia, subacute spongiform encephalopathy, and prion dementia.