{Reference Type}: Journal Article
{Title}: DNA methylation levels at individual age-associated CpG sites can be indicative for life expectancy.
{Author}: Lin Q;Weidner CI;Costa IG;Marioni RE;Ferreira MR;Deary IJ;Wagner W;
{Journal}: Aging (Albany NY)
{Volume}: 8
{Issue}: 2
{Year}: Feb 2016
{Factor}: 5.955
{DOI}: 10.18632/aging.100908
{Abstract}: DNA-methylation (DNAm) levels at age-associated CpG sites can be combined into epigenetic aging signatures to estimate donor age. It has been demonstrated that the difference between such epigenetic age-predictions and chronological age is indicative for of all-cause mortality in later life. In this study, we tested alternative epigenetic signatures and followed the hypothesis that even individual age-associated CpG sites might be indicative for life-expectancy. Using a 99-CpG aging model, a five-year higher age-prediction was associated with 11% greater mortality risk in DNAm profiles of the Lothian Birth Cohort 1921 study. However, models based on three CpGs, or even individual CpGs, generally revealed very high offsets in age-predictions if applied to independent microarray datasets. On the other hand, we demonstrate that DNAm levels at several individual age-associated CpGs seem to be associated with life expectancy - e.g., at CpGs associated with the genesPDE4C and CLCN6. Our results support the notion that small aging signatures should rather be analysed by more quantitative methods, such as site-specific pyrosequencing, as the precision of age-predictions is rather low on independent microarray datasets. Nevertheless, the results hold the perspective that simple epigenetic biomarkers, based on few or individual age-associated CpGs, could assist the estimation of biological age.