Research Paper Volume 14, Issue 14 pp 5641—5668
Aging the brain: multi-region methylation principal component based clock in the context of Alzheimer’s disease
Figure 2. Understanding core principal component composition. Principal component loadings for individuals in the training dataset were correlated using biweight midcorrelation (bicor) to selected author-provided phenotypic annotations (A). The same procedure was applied to the projected principal component loadings for all individuals in the test dataset, including those with and without Alzheimer’s disease (B). To ensure that future correlations between age prediction and disease are not the result of unrealistic distortions in PC loadings following the prediction process, we used ridgeplots to visualize the distribution of loadings in each PC in age 65+ training individuals (C) and the test data (D). [Abbreviations: NPCs: neural progenitor cells; Cort: cortical; ESCs: embryonic stem cells; DA: dopaminergic].