Familial neurological disease associated with spongiform encephalopathy.

In a family in whom susceptibility to neurological diseases was transmitted in autosomal dominant fashion, the diseases affecting different family members ranged from subacute and chronic dementias to various motor system abnormalities without dementia. The propositus suffered a typical clinical course of Creutzfeldt-Jakob disease. Neuropathological observations revealed spongiform encephalopathy. A first cousin had a chronic dementia; no spongiform changes were present at autopsy. Both patients had PAS-positive, eosinophilic plaques throughout the brain. Muscle biopsy of the propositus revealed some changes suggestive of "ragged-red" myopathy. The heterogeneity of disease and the inheritance pattern in this family suggests that general susceptibility to neurological disease is a genetic trait.