- 826studies in the library match, of 29,380
- 559name it in the title
- 1975–2026years published
- 799peer-reviewed articles
The query: title or abstract mentions "Down syndrome", "Down's syndrome" or "trisomy 21", matched case-insensitively against each record's title and abstract (its summary field) in alzhub's library of 29,380 study records, as of 2026-11-08. Every count on this page comes from that match. The matched list as JSON.
Chromosome 21 carries the APP gene, so three copies of the chromosome mean more amyloid-beta from birth. Plaques appear decades earlier than in the general population, and dementia follows in a large share of adults from their fifties onward. Because the sequence is so predictable, Down syndrome is studied as a genetic form of Alzheimer's, and biomarkers and treatments are being tested in this group specifically.
This page describes what published research in alzhub's library reports. It is not medical advice and does not apply to any one person: a doctor who knows the person's history is the only one who can say what a result or a treatment means for them.
What the studies report, in their own words
Whole sentences copied from the abstract or key findings of the highest-scoring matched studies, chosen because they mention the subject and give a figure. 8 of the 826 matched records are quoted; each links to its study page and from there to the paper.
“From May 13, 2015, to July 22, 2020, 185 participants with Down syndrome were assessed for eligibility and 160 (86%) were randomly assigned either memantine (n=81) or placebo (n=79).”
“US mortality data revealed an increase in life expectancy in Down syndrome (median [IQR], 1 [0.3-16] years in 1968 to 57 [49-61] years in 2019), but with clear ceiling effects in the highest percentiles of age at death in the last decades (90th percentile: 1990, age 63 years; 2019, age 65 years).”
“For samples of people with Down syndrome, the pooled estimate from data in 13 studies was 12.4% (95% CI 9.1-16.7), decreasing to 10.3% (95% CI 8.4-12.6) following removal of two studies focusing on older people.”
“These findings suggest that plasma p-tau217 and GFAP might be valuable for prognostic assessment of Alzheimer's disease in people with Down syndrome in both clinical and research contexts.”
“Specific 2024 updates include guidance on fracture risk assessment by ethnicity, Parkinson's disease, Down's syndrome and lower-limb amputation; furthermore, the definition of very high fracture risk has been clarified.”
“Results There were 132 720 unique adults with Down syndrome from 2011 to 2019: 79 578 (53.2%) were male, 17 090 (11.7%) were non-Hispanic Black, 20 777 (15.7%) were Hispanic, 101 120 (68.8%) were non-Hispanic White, and 47 692 (23.3%) had ever had an Alzheimer dementia diagnosis.”
“METHODS Longitudinal PiB (n=175 participants) and FBP (n=92 participants) data from the Alzheimer Biomarkers Consortium-Down Syndrome were used to measure cortical and striatal binding.”
“Our work revealed similar prevalence, age at diagnosis and Cambridge Cognitive Examination for Older Adults with Down Syndrome scores by sex, but males showed lower modified cued recall test scores from age 45 compared with females.”
What kind of evidence it is
By study design
| Design (as recorded) | Studies |
|---|---|
| Systematic review or meta-analysis | 4 |
| Randomised controlled trial | 2 |
| Other clinical trial | 4 |
| Cohort or longitudinal study | 56 |
| Case-control study | 8 |
| Cross-sectional study | 34 |
| Other recorded design | 7 |
| No design recorded | 711 |
The design is the one named in alzhub's record for the study; a record with none is counted as "no design recorded".
By year
| Year | Studies | Share |
|---|---|---|
| 2026 | 48 | |
| 2025 | 70 | |
| 2024 | 30 | |
| 2023 | 18 | |
| 2022 | 20 | |
| 2021 | 25 | |
| 2020 | 29 | |
| 2019 | 28 | |
| 2018 | 24 | |
| 2017 | 22 | |
| 2016 and earlier | 512 |
Other counts within the matched set
| Peer-reviewed articles | 799 |
| Marked open access in the record | 194 |
| Rated "high" evidence strength in alzhub's summary | 12 |
| Rated "moderate" evidence strength in alzhub's summary | 102 |
| Rated "low" evidence strength in alzhub's summary | 706 |
| No evidence-strength rating | 6 |
| Records stating a participant count | 198 |
| Median participants (those records) | 76 |
| Largest participant count | 847,430 |
Within the 826 matched studies
| Studies… | Count | Rule |
|---|---|---|
| …that mention blood or spinal fluid biomarkers | 170 | the abstract also contains "plasma", "biomarker", "CSF" or "cerebrospinal" |
| …that mention a clinical trial | 22 | the abstract also contains "trial" |
| …that mention age of onset or age at diagnosis | 197 | the abstract also contains "age of/at onset", "age at diagnosis" or "onset" |
The 10 highest-scoring matched studies
Title matches first, then by alzhub's usefulness score, which rates a study's design, journal, evidence and recency, not whether its result is good news.
- Safety, efficacy, and tolerability of memantine for cognitive and adaptive outcome measures in adolescents and young adults with Down syndrome: a randomised, double-blind, placebo-controlled phase 2 trial
- Association of Alzheimer Disease With Life Expectancy in People With Down Syndrome
- Prediction of amyloid and tau brain deposition and cognitive decline in people with Down syndrome using plasma biomarkers: a longitudinal cohort study
- Safety, Tolerability, and Immunogenicity of the ACI-24 Vaccine in Adults With Down Syndrome: A Phase 1b Randomized Clinical Trial
- Cognitive and functional performance and plasma biomarkers of early Alzheimer's disease in Down syndrome
- Association of Dementia With Mortality Among Adults With Down Syndrome Older Than 35 Years
- The Alzheimer's Biomarker Consortium-Down Syndrome: Rationale and methodology
- Comparison of tau spread in people with Down syndrome versus autosomal-dominant Alzheimer's disease: a cross-sectional study
- The efficacy, safety, and tolerability of donepezil for the treatment of young adults with Down syndrome
- The Down Alzheimer Barcelona Neuroimaging Initiative (DABNI) and its contributions to understanding Alzheimer's disease in Down syndrome: A decade of discovery
Systematic reviews and meta-analyses in the set
4 of the matched records are recorded as a systematic review, meta-analysis or umbrella review; the highest-scoring not already listed above:
- Prevalence of epilepsy among people with intellectual disabilities: A systematic review
- The 2024 UK clinical guideline for the prevention and treatment of osteoporosis
- Emerging Putative Associations between Non-Coding RNAs and Protein-Coding Genes in Neuropathic Pain: Added Value from Reusing Microarray Data
Newest matched studies
- Differential endothelial cell remodeling in Down syndrome and APP duplication drives distinct blood brain barrier dysfunction
- Memory and Plasma pTau217 Refine Prognosis in Down Syndrome
- Tau extent is associated with lower cognition in Down syndrome-related Alzheimer's disease
- Epilepsy Mechanisms in Down Syndrome: Genetic and Pathophysiological Perspectives Across the Lifespan
- Sleep Health in Adults with Intellectual Disability: Recent Advances and Persistent Evidence Gaps
Journals with the most matched studies
| Journal | Studies |
|---|---|
| Proceedings of the National Academy of Sciences of the United States of America | 30 |
| Alzheimer's & dementia : the journal of the Alzheimer's Association | 24 |
| Alzheimer s & Dementia | 21 |
| Neurobiology of aging | 21 |
| Journal of Alzheimer's disease : JAD | 20 |
Questions
- Why does Down syndrome lead to Alzheimer's?
- The amyloid precursor protein (APP) gene sits on chromosome 21, so a third copy of the chromosome means more amyloid-beta is produced throughout life, and plaques form decades earlier than usual. The studies below measure when changes appear and how they progress.
- How many studies on down syndrome and alzheimer's does alzhub hold?
- 826 of the 29,380 study records in alzhub's library match the query "title or abstract mentions "Down syndrome", "Down's syndrome" or "trisomy 21""; 559 of them name it in the title. Counted from the records when this page was built.
- What kinds of study are they?
- 4 systematic review or meta-analysis, 2 randomised controlled trials, 4 other clinical trials, 56 cohort or longitudinal studys, 8 case-control studys, 34 cross-sectional studys; 711 record no design.
- What is the most recent study in the set?
- "Differential endothelial cell remodeling in Down syndrome and APP duplication drives distinct blood brain barrier dysfunction" (bioRxiv, 2026), the newest by publication date among the matched records.
- Which journals publish most on it?
- Proceedings of the National Academy of Sciences of the United States of America (30); Alzheimer's & dementia : the journal of the Alzheimer's Association (24); Alzheimer s & Dementia (21), counted across the matched records.
Read on
- Down syndrome: research in the libraryThe subject hub, every study ranked.
- Is Alzheimer's hereditary?The other genetic forms.