The Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS): A 10-year report.

Introduction: Virtually all adults with Down syndrome (DS) will accumulate the neuropathologies associated with Alzheimer's disease (AD) by age 40, with the majority having a clinical dementia diagnosis by their middle 50s.

Methods: This paper complements a 2020 publication describing the Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS) methodology by highlighting protocol changes since initial funding in 2015. It describes available clinical, neuropsychological, neuroimaging, and biofluid data and bio-specimen repository. Ten years of accomplishments are summarized.

Results: Over 500 adults with DS and 59 sibling controls have been enrolled since 2015 with nearly 800 follow-up visits. More than 900 magnetic resonance imaging (MRI), 800 amyloid positron emission tomography (PET), and 600 tau PET scans have been conducted; multiple omics data have been generated using over 1100 blood and 100 cerebrospinal fluid (CSF) samples.

Discussion: ABC-DS is the largest U.S.-based, multi-site (including the United Kingdom and Puerto Rico), longitudinal biomarker initiative to target adults with DS at risk for AD.

Highlights: The Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS) is entering its 10th year. Over 500 adults with Down syndrome (DS) and 59 sibling controls have been enrolled. More than 900 magnetic resonance imaging (MRI), 800 amyloid positron emission tomography (PET), and 600 tau PET scans have been conducted. Multiple omics data have been generated using over 1100 blood and 100 cerebrospinal fluid (CSF) samples. It is positioned to continue to make substantial contributions to the DS field.