Environmental epigenetics has potential for preventing and treati...( New research on environmental influe...)

New research on environmental influences on health and disease has begun to shed light on why genetically identical individuals demonstrate different characteristics, such as susceptibility to disease. Scientists have found that environmental exposure to nutritional, chemical and physical factors can alter the epigenome. Literally meaning above the genome, the epigenome refers to differences in gene expression that are inherited without changing the sequence of DNA.

An article publishing in the January 2008 issue of Environmental and Molecular Mutagenesis examines some of the epigenetic mechanisms linked to disease, and explores how they occur and their significance in understanding, treating and preventing disease. Environmental and Molecular Mutagenesis, the official journal of the Environmental Mutagen Society, is published by John Wiley & Sons, Inc. and is available online via Wiley InterScience at http://www3.interscience.wiley.com/cgi-bin/jissue/114189787.

Authors Randy L. Jirtle and Dana C. Dolinoy of Duke University Medical Center in Durham, North Carolina, discuss genomic imprinting, a form of gene regulation in which epigenetic modifications in chromosomes result in differences in gene expression. First identified in 1991, there are approximately 80 imprinted genes that have been identified in mice and humans. Because imprinted genes behave as if they have a single set of chromosomes rather than the usual two, the health consequences of mutations in these genes are potentially disastrous, resulting in diseases such as cancer and several severe pediatric developmental disorders. In addition, mutations that occur in non-imprinted regions can influence the regulation of imprinted genes. The authors previously demonstrated that imprinting evolved anywhere from 230 to 150 million years ago, arising in mammals with the evolution of the placenta. They note that the
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