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C9orf72 hexanucleotide repeat expansions in clinical Alzheimer disease
Harms M, Benitez BA, Cairns N, Cooper B, Cooper P, Mayo K, Carrell D, Faber K et al.. JAMA neurology, 2013-06-01
Topic: Amyloid, tau and blood-test diagnosis
Importance Hexanucleotide repeat expansions in the chromosome 9 open reading frame 72 (C9orf72) gene underlie a significant fraction of frontotemporal dementia and amyotrophic lateral sclerosis. Objective To investigate the frequency of C9orf72 repeat expansions in clinically diagnosed late-onset Alzheimer disease (AD). Design, setting, and patients This case-control study genotyped the C9orf72 repeat expansion in 872 unrelated familial AD cases and 888 control subjects recruited as part of the National Institute on Aging Late-Onset Alzheimer Disease Family Study cohort, a multisite collaboration studying 1000 families with 2 or more individuals clinically diagnosed as having late-onset AD.
Key findings
- Objective To investigate the frequency of C9orf72 repeat expansions in clinically diagnosed late-onset Alzheimer disease (AD).
- Design, setting, and patients This case-control study genotyped the C9orf72 repeat expansion in 872 unrelated familial AD cases and 888 control subjects recruited as part of the National Institute on Aging Late-Onset Alzheimer Disease Family Study cohort, a multisite collaboration studying 1000 families with 2 or more individuals clinically diagnosed as having late-onset AD.
- Main outcomes and measures We determined the presence or absence of the C9orf72 repeat expansion by repeat-primed polymerase chain reaction, the length of the longest nonexpanded allele, segregation of the genotype with disease, and clinical features of repeat expansion carriers.
- RESULTS Three families showed large C9orf72 hexanucleotide repeat expansions.
Why it matters
This case-control study genotyped the C9orf72 repeat expansion in people with clinically diagnosed late-onset Alzheimer's disease and in control subjects. It examined frequency only and reports no treatment, cure or prevention.
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Study details
- Study designcase-control study
- Evidence strengthModerate
How this study scored 56/100
Published in a leading specialty journal, and it is a case-control study. Scored zero for sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 9 / 10 | Tier 2 — leading specialty journal (JAMA neurology) |
| Journal's citation record | 2 / 4 | JAMA Neurology: journal h-index 235 (OpenAlex, 2026-10-29) |
| Study design | 6 / 12 | A case-control study |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2013 — within 20 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 | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| 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 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 102 times (OpenAlex, 2026-10-10) |
| Citations per year | 2 / 5 | 6.8 citations a year over 15 year(s) since 2013 |
| Impact for its field and year | 4 / 6 | Cited 9.6× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 6 other studies in this library |
| Still being cited | 1 / 4 | Cited 5 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Carlos C Cruchaga: h-index 102 (OpenAlex, whole career) |
| Institution's track record | 3 / 3 | University of Washington: institution h-index 3,540 (OpenAlex) |
| Multi-centre collaboration | 2 / 3 | OpenAlex lists 7 institution(s) in 1 country |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 23588422) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 56 / 100 | — |
What each of these 20 components measures, and what this score is not →
Read the original
- DOI: 10.1001/2013.jamaneurol.537
- PubMed: 23588422
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Harms, M., Benitez, B. A., Cairns, N., Cooper, B., Cooper, P., Mayo, K., et al. (2013). C9orf72 hexanucleotide repeat expansions in clinical Alzheimer disease. JAMA neurology. https://doi.org/10.1001/2013.jamaneurol.537
Vancouver
Harms M, Benitez BA, Cairns N, Cooper B, Cooper P, Mayo K, et al. C9orf72 hexanucleotide repeat expansions in clinical Alzheimer disease. JAMA neurology. 2013. doi:10.1001/2013.jamaneurol.537. PMID: 23588422.
BibTeX
@article{harms2013-23588422,
author = {Harms, M. and Benitez, B. A. and Cairns, N. and Cooper, B. and Cooper, P. and Mayo, K. and Carrell, D. and Faber, K. and others},
title = {{C9orf72 hexanucleotide repeat expansions in clinical Alzheimer disease}},
journal = {JAMA neurology},
year = {2013},
doi = {10.1001/2013.jamaneurol.537},
pmid = {23588422},
url = {https://doi.org/10.1001/2013.jamaneurol.537}
}
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