Fig. 1.

Methylation in MZ twin pairs is highly concordant at candidate metastable epialleles (MEs). Each plot shows probe-specific β values for 97 MZ (blue, twin 2 > twin 1) and 162 DZ (red, twin 2 < twin 1) twin pairs, at loci previously identified as bona fide or candidate MEs [13, 14]. Insets show locus-average mean square errors (MSE) across all the MZ and DZ twins. MSE is much lower in MZ compared to DZ twins. a VTRNA2-1, 15 probes, 10.6-fold lower MSE (in MZ vs. DZ). b DUSP22, 11 probes, 16.5-fold lower. c PAX8, eight probes, 2.5-fold lower. d CYP2E1, three probes, 10.8-fold lower. e SFT2D3, four probes, 3.1-fold lower. f CFD, one probe, 6.6-fold lower