Individual epigenetic variation: when, why, and so what?

Abstract

Epigenetics provides a potential explanation for how environmental factors modify the risk for common diseases among individuals. Interindividual variation in DNA methylation and epigenetic regulation has been reported at specific genomic regions including transposable elements, genomically imprinted genes and the 'inactive' X chromosomes in females. We currently have a very poor understanding of the factors that contribute to interindividual epigenetic variation. In particular, it is important to understand when during the life cycle epigenetic variation arises, why epigenetic regulation varies among individuals, and whether epigenetic interindividuality affects susceptibility to diet-related chronic disease. In this review we will summarize current progress toward answering these questions.