CODON H187R

This mutation was found in one GSS family from the United States. Nine cases were affected. The median age at onset has been 42 years (range 33– –50 years) and the duration of the illness ranges from 8 to 19 years (median 12 years). Clinically the disease is characterized by dementia, cerebellar ataxia, myoclonic jerks and seizures. Neuropathological examination revealed PrPd deposits in the cerebral cortex of a distinct “curly” appearance and laminar pattern. PrP plaques were absent and spongiform changes were not seen.