Fig. 1: Genome-wide analysis of DNA methylation in peripheral blood samples shows rapid changes in the first week of life.

A Overview of study design and sample collection from each day of life (DOL). B Volcano plot of differentially methylated regions significantly associated with DOL. The X-axis represents the average methylation change from DOL0-7, and the y-axis shows the number of CpGs within each region, which is a function of region size. C Correlation of t-test statistics for DOL regression model between main and validation cohorts. Each point is an individual observation from n = 308,655 data points measured in both cohorts. The solid line indicates the linear regression fit for DOL. A two-sided P-value for Pearson’s correlation coefficient (R) is shown. D Cross-sectional analyses of mean effect size (% methylation) at each time point, stratified by hypermethylation (gain) or hypomethylation (loss). E Methylation ratios expressed as percentage (y-axis) for DOL associated CpGs stratified by genomic feature (x-axis). Boxplots show the median and interquartile range (IQR, 25th-75th percentile). Whiskers extend to the most extreme data points within 1.5 times the IQR from the box hinges (the 25th and 75th percentiles). Points outside this range are considered outliers and are plotted individually). UTR = untranslated region.Total n = 1267 samples.