DIAN Observational Study
Dominantly Inherited Alzheimer Network Observational Study (DIAN Obs)
International longitudinal study of adult children of parents with an APP, PSEN1 or PSEN2 mutation, comparing mutation carriers with non-carrier siblings using 3T MRI (incl. T2*-GRE or SWI with microbleed reads), PiB, FDG and tau PET, fluids and cognition.
Overview
The DIAN Observational Study follows families that carry a mutation causing dominantly inherited Alzheimer disease (DIAD) in the APP, PSEN1 or PSEN2 gene. Adult children of an affected parent are enrolled whether or not they carry the mutation, so the non-carrier siblings form a natural control group. Because the expected age at symptom onset is known for each mutation, the study can place every participant on a timeline relative to onset and track changes years before symptoms. The network is led by Washington University in St. Louis and runs sites in the Americas, Europe, Asia and Australia.
Composition
As of mid-2023 the study website lists 673 enrolled participants, about three quarters of them without symptoms. Of the 657 with confirmed mutation data, 397 carry a mutation and 260 do not. Participants return every one or two years, so most have several visits. Clinical, cognitive, genetic, CSF and blood biomarker data and neuropathology from autopsies come with the images.
Acquisition
MRI follows ADNI-based protocols on 3T scanners: MPRAGE, FLAIR, T2-weighted, diffusion, resting-state fMRI, ASL and a gradient echo scan for microbleeds. In the 2021 microbleed analysis this was a 2D T2*-GRE with 4 mm slices for 240 participants and SWI with 2 mm slices for 234 at baseline, and 153 participants switched from SWI to T2*-GRE at follow-up. PET covers PiB amyloid, FDG and, at some sites, tau. Imaging is held in the DIAN Central Archive.
Annotations
There are no voxel masks. Radiologists at Mayo Clinic read the gradient echo scans for cerebral microhemorrhages, superficial siderosis and macrohemorrhages, giving counts and lobar, deep or cerebellar location per visit, with longitudinal scans reviewed side by side. In the 511 participants analysed, 32 had microhemorrhages at baseline, 4 had superficial siderosis and 2 had macrohemorrhages. FreeSurfer volumes and white matter hyperintensity volumes are also available.
Known limitations
- The microbleed sequence changed from SWI to T2*-GRE at some sites, which affects detection sensitivity.
- Microbleed findings are counts and locations from visual reads, not segmentations.
- The exact mutation is not stored in the central archives, and mutation status is released only when a request keeps participants de-identified.
- Raw images need a justification in the request; processed data are the default.
Cohort
Aggregate numbers from the sources below. Bars are relative to the 673 subjects.
Contrast / sequence
subjects, values can overlap
- T2*-weighted 240 36%
- Susceptibility-weighted 234 35%
Condition
subjects, values can overlap
- Alzheimer's disease 397 59%
- Healthy control 260 39%
- Cerebral microbleeds 32 5%
- Superficial siderosis 4 <1%
- Intracerebral hemorrhage 2 <1%
License and access
Our reading of the license, not legal advice. Before you use the data, read the original license and confirm that your use is allowed. We take no responsibility for how you use a dataset. Full disclaimer
A research proposal is reviewed and approved
DIAN Observational Study Data Request Terms and Obligations
Research use within a project approved by the DIAN Obs PI and core leaders, after IRB documentation, a signed Code Access Agreement and a Data Use Agreement. No sharing with third parties without Steering Committee permission, all generated data go back to DIAN, publications name DIAN as an author and manuscripts go to DIAN 4 weeks before journal submission.
Raw imaging data must be justified in the request, and novel processing may be limited or charged.
What you can do
- Not stated
- Not stated
- Conditional
- Conditional
What you can share
- No
- Not stated
- Share trained models Not stated
What you must do
- Yes
- Share alike No
- Yes
- Yes
- Yes
- Release code No
- Yes
- Conditional
Limits
- Yes
- No
Citation
Include "Dominantly Inherited Alzheimer Network (DIAN)" as an author and the acknowledgement text from the DIAN Obs publication policy. Microbleed reads: Joseph-Mathurin N, et al. Longitudinal Accumulation of Cerebral Microhemorrhages in Dominantly Inherited Alzheimer Disease. Neurology 96(12):e1632-e1645 (2021). doi:10.1212/WNL.0000000000011542
All numbers
Every number on this page, as stored in stats.csv, with its source.
| Measure | Breakdown | Value | Source |
|---|---|---|---|
| Subjects | total enrolled participants (510 asymptomatic, 163 symptomatic) | 673 | dian-obs-available Participant Characteristics at Enrollment |
| Subjects | condition=alzheimers mutation carriers (APP, PSEN1 or PSEN2), asymptomatic or symptomatic, among the 657 with confirmed mutation data as of 30 June 2023 | 397 | dian-obs-available Participant Characteristics at Enrollment (footnote) |
| Subjects | condition=healthy mutation non-carriers among the 657 with confirmed mutation data as of 30 June 2023; siblings serving as controls | 260 | dian-obs-available Participant Characteristics at Enrollment (footnote) |
| Subjects | contrast=T2starw 2D T2*-GRE at the baseline visit, in the 511 participants with Mayo Clinic reads from the 14th data freeze | 240 | josephmathurin2021 Methods (Image Acquisition Protocol) |
| Subjects | contrast=swi SWI at the baseline visit, in the same 511-participant analysis; 153 switched from SWI to T2*-GRE at follow-up | 234 | josephmathurin2021 Methods (Image Acquisition Protocol) |
| Subjects | condition=cerebral_microbleeds cerebral microhemorrhages at baseline among the 511 analysed (26 carriers, 6 non-carriers) | 32 | josephmathurin2021 Results (CMH Prevalence and Location) |
| Subjects | condition=superficial_siderosis among the 511 analysed | 4 | josephmathurin2021 Results (CMHs, Other ARIA-H, and White Matter Lesions) |
| Subjects | condition=intracerebral_hemorrhage macrohemorrhages, both in APP mutation carriers, among the 511 analysed | 2 | josephmathurin2021 Results (CMHs, Other ARIA-H, and White Matter Lesions) |
Sources
The keys used in the table above.
- dian-obs-available DIAN website, DIAN Obs data and biospecimens available for request (enrolment table as of 30 June 2023) website
- josephmathurin2021 Joseph-Mathurin et al. 2021, Longitudinal accumulation of cerebral microhemorrhages in DIAD, Neurology paper