Home › Research › How common it is
Mitochondrial DNA copy number in neurodegenerative diseases: a global meta-analysis of 156 comparisons across 76 studies
Mathews R, Bouyadjera SB, Donegan JJ, Havird JC.. bioRxiv, 2026-08-29
Topic: Genetics and APOE
Consequently, changes in mitochondrial DNA copy number (mtDNA-CN), the number of mtDNA genomes per cell or tissue sample, are associated with diseases ranging from cancer and obesity to psoriasis and all-cause mortality. MtDNA-CN especially holds promise as a biomarker for neurodegenerative diseases given the high-energy demands of neurons, but the relationship between neurodegeneration and mtDNA-CN is controversial due to mixed results among studies. Overall, mtDNA-CN was ∼5.3% lower with neurodegeneration, but the difference was not statistically significant (14% decrease – 4% increase, P = 0.244), with extreme heterogeneity among studies ( I 2 = 99.5%). Results varied significantly among neurodegenerative diseases, with Alzheimer’s showing a convincing 21% decrease in mtDNA-CN, but no change in mtDNA-CN in Parkinson’s despite large sample sizes. Surprisingly, the tissue and assay method used to quantify mtDNA-CN did not influence overall patterns. However, significant interactions were found among moderators. We conclude that the general perception of decreased mtDNA-CN with neurodegeneration is a vast oversimplification that may stem from “legacy” effects of early studies. Significance statement Mitochondrial dysfunction is associated with many diseases and the number of mitochondrial genome copies in a given (mtDNA-CN) is a promising biomarker for overall health and disease risk. While mtDNA-CN has been linked to neurodegenerative diseases, many studies find contradictory results. Overall, we found only a small, statistically non-significant decrease in mtDNA-CN with neurodegeneration, but results varied widely among studies.
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
APA 7th
Mathews, R., Bouyadjera, S. B., Donegan, J. J., & Havird, J. C. (2026). Mitochondrial DNA copy number in neurodegenerative diseases: a global meta-analysis of 156 comparisons across 76 studies. bioRxiv. https://doi.org/10.64898/2026.08.25.747144
Vancouver
Mathews R, Bouyadjera SB, Donegan JJ, Havird JC. Mitochondrial DNA copy number in neurodegenerative diseases: a global meta-analysis of 156 comparisons across 76 studies. bioRxiv. 2026. doi:10.64898/2026.08.25.747144.
BibTeX
@article{mathews2026-7aad1a5f,
author = {Mathews, R. and Bouyadjera, S. B. and Donegan, J. J. and Havird, J. C.},
title = {{Mitochondrial DNA copy number in neurodegenerative diseases: a global meta-analysis of 156 comparisons across 76 studies}},
journal = {bioRxiv},
year = {2026},
doi = {10.64898/2026.08.25.747144},
url = {https://doi.org/10.64898/2026.08.25.747144}
}
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. Check the citation against the original before you use it.
Key findings
- Consequently, changes in mitochondrial DNA copy number (mtDNA-CN), the number of mtDNA genomes per cell or tissue sample, are associated with diseases ranging from cancer and obesity to psoriasis and all-cause mortality.
- MtDNA-CN especially holds promise as a biomarker for neurodegenerative diseases given the high-energy demands of neurons, but the relationship between neurodegeneration and mtDNA-CN is controversial due to mixed results among studies.
- Overall, mtDNA-CN was ∼5.3% lower with neurodegeneration, but the difference was not statistically significant (14% decrease – 4% increase, P = 0.244), with extreme heterogeneity among studies ( I 2 = 99.5%).
- Results varied significantly among neurodegenerative diseases, with Alzheimer’s showing a convincing 21% decrease in mtDNA-CN, but no change in mtDNA-CN in Parkinson’s despite large sample sizes.
- Surprisingly, the tissue and assay method used to quantify mtDNA-CN did not influence overall patterns.
New to this subject? Start with our plain-English guide: Alzheimer's in numbers →
Study details
- Study designsystematic review
- Effect size5.3%; 99.5%; 85.7%
- Evidence strengthHigh
How this study scored 16/100
Preprint — not yet peer-reviewed. It scored 50 on the same rubric, but non-peer-reviewed sources are capped at 16, so it shows as 16. Scored zero for sample size and studied in people because the record does not state it. We have no data on times cited, citations per year, impact for its field and year, cited by studies here, still being cited, senior author's track record, institution's track record and multi-centre collaboration, so those were left out: it earned 31 of the 62 points we could judge it on, which is 50 out of 100.
| Component | Points | Why |
|---|---|---|
| Journal tier | 2 / 10 | Tier 4 — not a peer-reviewed journal (bioRxiv) |
| Journal's citation record | 0 / 4 | Not a journal article, so the journal's record does not count |
| Study design | 12 / 12 | A systematic review of all the studies on the question |
| Strength of evidence | 5 / 5 | Rated “high” in our summary |
| Peer-review validation | 4 / 10 | Preprint — not yet peer-reviewed. Hosted on a preprint server. |
| How recent | 5 / 5 | 2026 — within 1 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 2 / 3 | Effect reported as a number, without an interval or test |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | A review of other studies — randomisation is not credited here |
| Times cited | — / 7 | No citation count (not found in OpenAlex) — left out of this score |
| Citations per year | — / 5 | No citation count or no year — left out of this score |
| Impact for its field and year | — / 6 | No field-weighted citation impact (OpenAlex has none yet) — left out of this score |
| Cited by studies here | — / 6 | Not yet checked against this library's citation graph — left out of this score |
| Still being cited | — / 4 | No yearly citation counts — left out of this score |
| Senior author's track record | — / 4 | Senior author's record not available — left out of this score |
| Institution's track record | — / 3 | No institution listed in OpenAlex — left out of this score |
| Multi-centre collaboration | — / 3 | Institutions not listed — left out of this score |
| Indexed in PubMed | 1 / 2 | Not in PubMed, but has a DOI |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Points | 31 / 62 | Scored on 12 of 20 parts. We have no data for the rest, so they are left out: 31 of the 62 points we could judge it on is 50 out of 100. |
| Total | 50 / 100 | Capped to 16 because this is not a peer-reviewed article. |
What each of these 20 components measures, and what this score is not →
Read the original
Free copy unknown: no free-copy check has an answer for this record yet. That does not mean it is paywalled.
Related studies in How common it is
Also tagged “oxidative”
275 studies in the library carry the topic tag “oxidative”; these are this study's neighbours in a fixed, alphabetical-by-hash tour of them, not the closest in content. All 275 tagged studies.