17 de setembre 2015

Epigenetics contribution to clarify disease mechanisms

Epigenetics at the Crossroads of Genes and the Environment

You may find an updated definition of epigenetics in this JAMA article:
 Epigenetics refers to information transmitted during cell division other than the DNA sequence per se, and it is the language that distinguishes stem cells from
somatic cells, one organ from another, and even identical twins from each other. Examples include (1) DNA methylation, a covalent modification of the nucleotide cytosine, that is copied during cell division at CpG dinucleotides by the maintenance enzyme DNA methyltransferase I; (2) posttranslational modifications of nucleosome proteins about which the DNA double helix is wrapped; and (3) the density of  nucleosomes and higher-order packaging of chromatin within the nucleus, including its relationship to the nuclear lamina.
If this is so, why is the message of predictive genetics so widespread?. I've insisted on this issue before.
 The field of epigenetics and epigenetic epidemiology have much to do to improve measurement of epigenetic marks, inform natural variation in such marks, and the biological and population level relationships between genes, environment, and epigenetics. This is an important emerging area as it holds promise for better risk prediction in precision medicine as well as for clarification of disease mechanisms among the existing opaque landscape only partially informed by traditional genetic and environmental studies to date.
 A short and relevant article that provides hints for further reading.

PS. Epigenetic phenomena, from Nature.