Mixed features of Alzheimer disease and Creutzfeldt-Jakob disease in a family with a presenilin 1 mutation in chromosome 14

Alzheimer disease and Creutzfeldt-Jakob disease are both characterized by the onset in late-middle age of progressive dementia with a fatal outcome, and a degenerative neuropathology with neuronal loss and amyloid deposition. Whereas early studies underlined clinico-pathologic and genetic similarities between the two diseases, the more recent discovery of pathogenic mutations in genes on different chromosomes producing chemically distinct amyloids has emphasized their differences. We here describe a family with clinico-pathologic features of both diseases, including substantial cerebral deposition of both beta A4 and PrP amyloid proteins, in which the pathogenesis is linked to a mutation in codon 163 of the presenilin 1 (S182, AD3) gene on chromosome 14.