For Researchers

ABC-DS is committed to providing rapid public access to all data, clinical, cognitive and biomarker (fluid and imaging) data, and access to the biological samples for qualified scientific investigators, without embargo.

Why should I get involved in the research?

The Alzheimer Biomarker Consortium-Down Syndrome (ABC-DS) project is one of the world’s largest, most comprehensive longitudinal research initiatives to find biomarkers to track Alzheimer’s disease in people with Down syndrome.

A list of publications associated with ABC-DS data is available through:

Data Types

Common core measures, collected at multiple time points to support longitudinal analyses, include:

Direct cognitive and functional measures

tests of memory, visual spatial abilities, language, executive function, processing speed, mental status, and gait

Blood-based biomarkers

a proteomics panel, a metabolomics panel, and an assay of plasma Aβ peptides—Aβ40, Aβ42, Aβ40/Aβ42 ratio, tau, and neurofilament light change protein, and in willing participants, cerebrospinal fluid (CSF) biomarkers.

Caregiver questionnaires

queries on functional abilities, mental status, neuropsychiatric symptoms, and dementia screening

Genetic studies

genome-wide association analysis focusing on variants in genes associated with Alzheimer’s and age at onset of Alzheimer’s and memory decline, and with individual differences in blood-based, imaging, and CSF biomarkers that are found to be associated with clinical disease progression including Aβ42, P181-tau, and total tau

Medical and neurological assessments

personal and family health history, medication usage, and a brief physical and neurological examination

Brain Donation

for people willing to participate in brain donation, neuropathology will be assessed to link to cognitive, neuroimaging and fluid biomarkers.

Neuroimaging biomarkers

MRI-based measures of cortical thickness and volume, white matter abnormalities and microstructure and functional connectivity, as well as amyloid-, tau-, and FDG-PET

There will be three to four cycles of assessment, at approximately 16-month intervals, over the five-year study. However, some procedures will only be included in selected cycles.

Cohort Data



Enrollment by Race or Ethnicity

Participant Activity Count

Residence Type

Consensus Diagnosis

Age of Mother at Participant's Birth

Age of Father at Participant's Birth

Data Dictionary

Details and information for the collected data and biospecimens can be found in the data dictionary.

View the Data Dictionary

How to Apply for Data Access

Data from the ABC-DS study is transferred to the Laboratory of Neuro Imaging (LONI), for harmonization, documentation and de-identification. Biospecimen samples are transferred and managed by the National Centralized Repository for Alzheimer’s Disease and Related Dementias (NCRAD) and an ABC-DS biospecimen bank. As of May 2021, data from the first and second wave of longitudinal data are available to researchers by requests.

Step 1

Fill out quatrix request

Step 2

Review and sign the ABC-DS Data Use AgreementFill out quatrix request

Step 3

Your request will undergo committee review. 

Step 4

You will be notified once you are approved or if we require more information.

Step 5

Once approved, you will have access to data from the study through LONI.

Researchers, Apply for Data Access Today

Qualified investigators are welcome to submit requests for access to data and samples.

All requests will be reviewed by ABC-DS investigators and NIH staff.

Approved data requests will be managed by the ABC-DS Biostatistics and Data Management Core for access to the clinical, cognitive, and neuroimaging data listed below.

Upon approval and availability of biospecimen samples, NCRAD will distribute DNA, plasma and serum. The ABC-DS biospecimen bank will distribute CSF.

LONI will store the associated data for access by approved investigators.

Fill Out Data Request