title: Familial prion disease with Alzheimer disease-like tau pathology and clinical phenotype.
abstract: OBJECTIVE
  To describe the Alzheimer disease (AD)-like clinical and pathological features, including marked neurofibrillary tangle (NFT) pathology, of a familial prion disease due to a rare nonsense mutation of the prion gene (PRNP).
  
  
  METHODS
  Longitudinal clinical assessments were available for the proband and her mother. After death, both underwent neuropathological evaluation. PRNP was sequenced after failure to find immunopositive Aβ deposits in the proband and the documentation of prion protein (PrP) immunopositive pathology.
  
  
  RESULTS
  The proband presented at age 42 years with a 3-year history of progressive short-term memory impairment and depression. Neuropsychological testing found impaired memory performance, with relatively preserved attention and construction. She was diagnosed with AD and died at age 47 years. Neuropathologic evaluation revealed extensive limbic and neocortical NFT formation and neuritic plaques consistent with a Braak stage of VI. The NFTs were immunopositive, with multiple tau antibodies, and electron microscopy revealed paired helical filaments. However, the neuritic plaques were immunonegative for Aβ, whereas immunostaining for PrP was positive. The mother of the proband had a similar presentation, including depression, and had been diagnosed clinically and pathologically as AD. Reevaluation of her brain tissue confirmed similar tau and PrP immunostaining findings. Genetic analysis revealed that both the proband and her mother had a rare PRNP mutation (Q160X) that resulted in the production of truncated PrP.
  
  
  CONCLUSIONS
  We suggest that PRNP mutations that result in a truncation of PrP lead to a prolonged clinical course consistent with a clinical diagnosis of AD and severe AD-like NFTs.
authors.affiliation: Department of Neurology, University of Washington, Seattle, WA, USA.
authors.forename: Suman
authors.initials: S
authors.lastname: Jayadev
authors.forename: David
authors.initials: D
authors.lastname: Nochlin
authors.forename: Parvoneh
authors.initials: P
authors.lastname: Poorkaj
authors.forename: Ellen J
authors.initials: EJ
authors.lastname: Steinbart
authors.forename: James A
authors.initials: JA
authors.lastname: Mastrianni
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Montine
authors.forename: Bernardino
authors.initials: B
authors.lastname: Ghetti
authors.forename: Gerard D
authors.initials: GD
authors.lastname: Schellenberg
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bird
authors.forename: James B
authors.initials: JB
authors.lastname: Leverenz
mesh_terms: D000328:Adult; D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D018389:Codon, Nonsense; D003865:Major Depressive Disorder / Q000235:genetics / Q000473:pathology; D005260:Female; D005973:Glutamine; D006801:Humans; D008569:Memory Disorders / Q000235:genetics / Q000473:pathology; D008570:Memory, Short-Term; D008875:Middle Aged; D016874:Neurofibrillary Tangles / Q000235:genetics* / Q000473:pathology*; D009483:Neuropsychological Tests; D010641:Phenotype; D017096:Prion Diseases / Q000235:genetics* / Q000473:pathology / Q000523:psychology; D000072002:Prion Proteins; D011328:Prions / Q000235:genetics* / Q000378:metabolism; D014443:Tyrosine; D016875:tau Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D018389:Codon, Nonsense; C512656:PRNP protein, human; D000072002:Prion Proteins; D011328:Prions; D016875:tau Proteins; D005973:Glutamine; D014443:Tyrosine