Fig. 3

Genome-wide methylation profiles of MZ twin pairs based on buccal-derived DNA measured on the EPIC array. a Scatterplot showing genome-wide methylation β-values of co-twins of 1 exemplary twin pair (median correlation). b Scatterplot showing genome-wide methylation β-values of co-twins of 1 exemplary twin pair (lowest correlation). c Scatterplot showing genome-wide methylation β-values of co-twins of 1 exemplary twin pair (highest correlation). d Histogram of correlations between samples from: MZ twins (purple), unrelated subjects (green), and replicates (same DNA sample run twice on EPIC; blue lines). e The correlation between genome-wide methylation values of twins (r, y  axis) is plotted against the absolute within-pair difference in epithelial cell percentage % (x axis). Samples are colored by age at DNA collection. f Relationship between the number of CpGs with a methylation difference > 30% between MZ twins (y axis) and within-pair difference in proportion of epithelial cells(x axis). Colors denote the mean proportion of buccal cells of the two twin samples. g Within-pair differences in one MZ twin pair assessed twice on EPIC (technical replicates). The scatterplot shows two replicate measures of the within-pair difference of this twin pair. Horizontal and vertical lines indicate within-pair difference greater than 30%. h Venn diagram of the overlap across four replicate measures (rep1–rep 4) of within-pair methylation differences > 0.3 detected in one MZ twin pair assessed twice on EPIC array