Down syndrome, beta-amyloid and neuroimaging

This review focuses on the role of A beta in AD pathogenesis in Down syndrome and current approaches for imaging A beta in vivo. We will describe how A beta deposits with age, the posttranslational modifications that can occur, and detection in biofluids. Three unique case studies describing partial trisomy 21 cases without APP triplication, and the occurrences of low level mosaic trisomy 21 in an early onset AD patient are presented. Brain imaging for A beta includes those by positron emission tomography and ligands (Pittsburgh Compound B, Florbetapir, and FDDNP) that bind A beta have been published and are summarized here. In combination, we have learned a great deal about A beta in DS in terms of characterizing age of onset of this pathology and it is exciting to note that there is a clinical trial in DS targeting A beta that may lead to clinical benefits.