Targeted epigenetic clock based on mortality-linked CpG sites tested for frailty
Researchers built a simplified epigenetic clock from three CpG sites linked to all-cause mortality and age, but in 446 ActiFE samples it did not significantly predict mortality and showed no clear link to frailty or age-related clinical parameters. [1]
Automatic summary · not editorially reviewed
The key findings
Three CpG sites strongly associated with all-cause mortality in the Lothian Birth Cohorts and with chronological age in public repositories formed the targeted age- and mortality-associated clock (TaM clock). [1]
In a subset of 20 frail and 20 non-frail ActiFE participants, the TaM clock showed a significant association between delta age and frailty status based on a 32-item frailty index. [1]
In 446 ActiFE samples, predictions from either targeted clock were not significantly associated with mortality, and there was no clear relationship with frailty or age-related clinical parameters. [1]
The source at a glance
- Study type / format
- Abstract of a biomarker development study with benchmarking and cohort analysis
- Population / context
- Participants of the ActiFE cohort, including 20 frail and 20 non-frail participants in the initial subset and 446 samples in the larger analysis.
- Summary based on
- Study abstract
- Original publication
- July 7, 2026
Three CpG sites chosen for mortality and age links
The authors aimed to build a simplified, targeted clock measurable by digital PCR, because second-generation epigenetic clocks need genome-wide profiles, which hampers practical use. They selected three CpG sites strongly associated with all-cause mortality in the Lothian Birth Cohorts and with chronological age in several public repositories, forming the targeted age- and mortality-associated clock (TaM clock). For comparison they used a previously published three-CpG signature chosen only for correlation with chronological age (TaC clock).
Supporting source [1]
Small frail/non-frail subset versus 446 ActiFE samples
Both signatures were first benchmarked on DNA methylation profiles from 20 frail and 20 non-frail ActiFE participants. In this subset the TaM clock showed a significant association between delta age and frailty status based on a 32-item frailty index, and it outperformed the TaC clock at capturing a significant increase in epigenetic age in Down syndrome, Werner syndrome and HIV. The team then developed digital PCR assays and analysed 446 ActiFE samples. One TaM site (cg20595453) was significantly associated with both mortality and frailty, but predictions from either targeted clock were not significantly associated with mortality, and there was no clear relationship with frailty or age-related clinical parameters in this larger cohort.
Supporting source [1]
Abstract-only limits in a relatively healthy cohort
The authors conclude that their targeted signatures were not sensitive enough to reliably predict frailty or mortality in a relatively healthy study population, which they describe as a general challenge for epigenetic clocks. They suggest that additional disease-associated target sites may be needed to support frailty analysis in personalized medicine. These are associations, not causal findings, and the abstract does not report follow-up duration or full methods; the full text was not reviewed.
Supporting source [1]
How to interpret this
Abstract only; the full text was not reviewed. The abstract does not report follow-up duration or full methods, and the findings are associations in a relatively healthy cohort, not causal effects.
Based on the study abstract; the full paper, tables and supplementary data were not reviewed.
Source & supporting passages
Awuah J, Dallmeier D, Boehm F, Herdtle L, Rothenbacher D, Perez-Correa JF, Wagner W. · europepmc.org · July 7, 2026