Figure 1. The epigenetic clock and Asthma Across the
Life Course . Panel A illustrates different environmental exposures
which may alter the rate of the epigenetic clock. Panel B is an
illustrative representation of the proportion of male vs. female
asthmatics over the life stages. Arrows show key changes in sex-specific
patterns of asthma prevalence as extrapolated from25,91,92and
are intended for illustrative purposes only. Panel C shows the different
life stages. DNAm during periods of significant hormone changes (e.g.,
puberty, pregnancy, and menopause) DNA is particularly vulnerable to
alteration by environmental exposures. Panel D shows the key genes
undergoing changes in methylation during development
(39,40,88).