Amyloid imaging with AV45 ((18)F-florbetapir) in a cognitively normal AβPP duplication carrier

Laure Saint-Aubert1, Mélanie Planton, Didier Hannequin

  • 1Inserm, Imagerie Cérébrale et Handicaps Neurologiques UMR 825, Toulouse, France.

Insights

A 62-year-old asymptomatic carrier of Amyloid Precursor Protein (AβPP) gene duplication shows Alzheimer's-like brain changes. This case highlights early, pre-symptomatic pathology in a gene duplication carrier.

Area of Science:

  • Neurogenetics
  • Neuropathology
  • Neuroimaging

Background:

  • Amyloid Precursor Protein (AβPP) gene duplication is a rare autosomal dominant cause of Alzheimer's disease.
  • Early diagnosis and understanding of pre-symptomatic carriers are crucial for therapeutic strategies.

Observation:

  • A 62-year-old male, asymptomatic for cognitive decline, was identified as a carrier of AβPP gene duplication.
  • Neuroimaging revealed cortical thickness and amyloid-beta (Aβ) deposition (18F-AV45 PET) comparable to Alzheimer's disease patients.
  • Neuropathological examination of his deceased younger brother revealed cerebral amyloid angiopathy and Alzheimer's disease pathology.

Findings:

  • This represents the first documented case of a pre-symptomatic AβPP duplication carrier over 60 years old.
  • The carrier exhibited significant "Alzheimer's-like" brain atrophy and widespread amyloid deposition despite the absence of clinical symptoms.
  • Cerebral amyloid angiopathy and Alzheimer's disease pathology were confirmed in a first-degree relative.

Implications:

  • AβPP gene duplication can lead to significant neuropathological changes years before symptom onset.
  • This case challenges the traditional timeline of Alzheimer's disease progression in genetic forms.
  • Further research into pre-symptomatic carriers is vital for developing early interventions and understanding disease mechanisms.