Epigenetic modifications are changes to gene regulation and expression which do not alter the DNA sequence itself. One epigenetic modification is DNA methylation - the binding of a methyl group to a cytosine. DNA methylation can be affect by environmental exposures and therefore can serve as biomarkers of environmental exposures.

Some environmental exposures can be difficult to measure. For example, maternal smoking during pregnancy (prenatal maternal smoking) has negative health impacts on the exposed child throughout the lifecourse, but prenatal maternal smoking can be difficult to measure. In cohorts of adults, individuals may be unaware of their exposure status, and even when mother’s are availble for interview, they may be reluctant to disclose prenatal smoking due to social desirability bias.

Investigations of cord blood and children’s peripheral blood has demonstrated that DNA methylation in blood samples can serve as an accurate and reliable biomarker of exposure to prenatal maternal smoking. In my current research work, I explore if DNA methylation from saliva samples serve the same purpose, and provide an easily collectable biomarker of prenatal exposures.