A ‘treasure map’ for epigenetic causes of diseases

The cell-specific nature of epigenetics makes it challenging to study, but new research has unveiled a possible “treasure map” to help understand the link between epigenetics and disease.

Epigenetics is a mechanism for marking sections of DNA that require expressional regulation. The most stable form of epigenetic regulation is the addition of methyl groups known as DNA methylation. This occurs in the embryonic state and can determine the fate of your health, establishing an association between epigenetics and disease.  A study, recently published in Genome Biology, profiled DNA methylation to map out regions called correlated regions of systemic interindividual variation (CoRSIVs), providing a new level of molecular individuality in humans.

“Since these tissues each represent a different layer of the early embryo, we’re essentially going back in time to events that occurred during early embryonic development.”

Epigenetics are important contributing factors to disease, with the ability to silence or activate genes. However, due to their cell-specific nature, they are problematic to study. A blood sample can often be used to genotype an individual providing an indication of the DNA damage present across all somatic cell types, however, epigenetic markers found in a blood test will provide very little information about the epigenetic dysregulation in cells from other tissues in the body.  Robert Waterland (Baylor University; TX, USA) analyzed DNA Methylation in genomes taken from cells of the thyroid, heart and brain, in each of 10 cadavers. The research team identified that while DNA methylation always differs between individuals, it is uniform at specific sites in the genome, known as CoRSIVs, throughout different tissues.

“Since these tissues each represent a different layer of the early embryo, we’re essentially going back in time to events that occurred during early embryonic development,” Waterland said. “To map DNA methylation, we converted methylation information into a genetic signal, then sequenced the genomes. Our atlas required massive amounts of sequencing data — 370 times more than were used for the first map of the human genome in 2001.”

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From this analysis of methylation patterns, the researchers were able to identify almost 10,000 CoRSIVs. These results could offer a gateway to understanding the disease processes from an epigenetic perspective, enabling future researchers to focus on these CoRSIVs when studying conditions affected by epigenetics. Waterland believes that these findings will transform the field of epigenetics, where recent research has already linked DNA methylation at the established CoRSIVs to a range of diseases such as obesity, cancer, autism, Alzheimer’s disease and cleft palate.